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5 GHz Unlicensed Spectrum (UNII)

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Released: February 20, 2013

Federal Communications Commission

FCC 13-22

Before the

Federal Communications Commission

Washington, D.C. 20554

In the Matter of
)
)

Revision of Part 15 of the Commission’s Rules to
)
Permit Unlicensed National Information
)
ET Docket No. 13-49
Infrastructure (U-NII) Devices in the 5 GHz Band
)

NOTICE OF PROPOSED RULEMAKING

Adopted: February 20, 2013

Released: February 20, 2013

Comment Date: [45 days after publication in the Federal Register]
Reply Comment Date: [75 days after publication in the Federal Register]

By the Commission: Chairman Genachowski and Commissioners McDowell, Clyburn, Rosenworcel, and
Pai issuing separate statements.

TABLE OF CONTENTS

Heading
Paragraph #
I. INTRODUCTION.................................................................................................................................. 1
II. BACKGROUND.................................................................................................................................... 3
III. DISCUSSION ...................................................................................................................................... 15
A. The Current U-NII Bands .............................................................................................................. 23
1. Unlicensed Operations in the U-NII-3 Band ........................................................................... 23
2. Unlicensed Operations in the U-NII-1 Band ........................................................................... 36
3. Ensuring Compliance with the Rules for the U-NII Bands ..................................................... 42
4. The U-NII-2A and U-NII-2C Bands ....................................................................................... 66
B. Future Unlicensed Operations at 5 GHz ........................................................................................ 75
1. Future Unlicensed Operations at 5 GHz.................................................................................. 78
2. Incumbent Services in the U-NII-2B Band ............................................................................. 82
3. Incumbent Services in the U-NII-4 Band................................................................................ 88
4. Technical Requirements for U-NII-2B and U-NII-4 Bands.................................................... 95
5. NTIA 5 GHz Report .............................................................................................................. 102
C. Other Issues.................................................................................................................................. 113
1. Miscellaneous Rule Modifications........................................................................................ 113
2. Transition Periods.................................................................................................................. 114
IV. PROCEDURAL MATTERS.............................................................................................................. 116
A. Ex Parte Rules – Permit-But-Disclose......................................................................................... 116
B. Comment Period and Procedures................................................................................................. 117
C. Initial Regulatory Flexibility Analysis......................................................................................... 119
D. Paperwork Reduction Analysis.................................................................................................... 120
E. Further Information...................................................................................................................... 121
V. ORDERING CLAUSES..................................................................................................................... 122

Federal Communications Commission

FCC 13-22

APPENDICES:
APPENDIX A-

Proposed Rules

APPENDIX B-

Compliance Measurement Procedures for U-NII Devices

APPENDIX C-

Existing Technical Summary Charts for Unlicensed Bands

APPENDIX D-

Initial Regulatory Flexibility Analysis

I.

INTRODUCTION

1.
By this Notice of Proposed Rulemaking (NPRM), we propose to amend Part 15 of our
rules governing the operation of Unlicensed National Information Infrastructure (U-NII) devices in the 5
GHz band.1 U-NII devices are unlicensed intentional radiators that operate in the frequency bands 5.15-
5.35 GHz and 5.47-5.825 GHz, and which use wideband digital modulation techniques to provide a wide
array of high data rate mobile and fixed communications for individuals, businesses, and institutions.2
Since the Commission first made available spectrum in the 5 GHz band for U-NII in 1997, we have
gained much experience with these devices. We believe that the time is now right for us to revisit our
rules, and, in this NPRM, we propose to modify certain technical requirements for U-NII devices to
ensure that these devices do not cause harmful interference and thus can continue to operate in the 5 GHz
band and make broadband technologies available for consumers and businesses.
2.
We also seek comment on making available an additional 195 megahertz of spectrum in
the 5.35-5.47 GHz and 5.85-5.925 GHz bands for U-NII use. This could increase the spectrum available
to unlicensed devices in the 5 GHz band by approximately 35 percent and would represent a significant
increase in the spectrum available for unlicensed devices across the overall radio spectrum. The initiation
of this proceeding satisfies the requirements of Section 6406 (a) of the “Middle Class Tax Relief and Job
Creation Act of 2012” which requires the Commission to begin a proceeding to modify part 15 of title 47,
Code of Federal Regulations, to allow unlicensed U-NII devices to operate in the 5350-5470 MHz band.3
We believe that an increase in capacity gained from 195 megahertz of additional spectrum, combined
with the ease of deployment and operational flexibility provided by our U-NII rules, would continue to
foster the development of new and innovative unlicensed devices, and increase wireless broadband access
and investment.

II.

BACKGROUND

3.
Part 15 of the Commission’s rules permits the operation of radio frequency devices
without issuing individual licenses to operators of these devices. The Commission’s Part 15 rules are
designed to ensure that there is a low probability that these devices will cause harmful interference to
other users of the same or adjacent spectrum. Typically, unlicensed devices operate at very low power
over relatively short distances, and often employ various techniques, such as dynamic spectrum access or
listen-before-talk protocols, to reduce the interference risk to others as well as themselves. The primary
operating condition for unlicensed devices is that the operator must accept whatever interference is
received and must correct whatever interference it causes. Should harmful interference occur, the
operator is required to immediately correct the interference problem or cease operation.4
4.
In 1997, the Commission made available 300 megahertz of spectrum at 5.15-5.25 GHz
(referred to hereinafter as U-NII-1), 5.25-5.35 GHz (referred to hereinafter as U-NII-2A), and 5.725-

1 See 47 C.F.R. Part 15 Subpart E – Unlicensed National Information Infrastructure Devices.
2 See 47 C.F.R. § 15.403(s).
3 See Middle Class Tax Relief and Job Creation Act of 2012, Pub. L. No. 112-96, § 6406, 126 Stat. 156, 231 (2012),
47 U.S.C. § 1453 (Spectrum Act).
4 See 47 C.F.R. §§ 15.5(b) and (c).
2

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FCC 13-22

5.825 GHz (referred to hereinafter as U-NII-3) for use by a new category of unlicensed equipment, called
U-NII devices which are regulated under Part 15, Subpart E of the Commission’s rules.5 In 2003, the
Commission made an additional 255 megahertz of spectrum available in the 5.47-5.725 GHz (referred to
hereinafter as U-NII-2C) for U-NII devices.6 These actions align the frequency bands used by U-NII
devices in the United States with the frequency bands used by U-NII devices in other parts of the world,
thus decreasing development and manufacturing costs by allowing for the same products to be used in
most parts of the world.
5.
The U-NII-1 band is allocated on a primary basis to the Aeronautical Radionavigation
Service for both Federal and non-Federal operations and on a primary basis for Fixed Satellite Service
(Earth-to–space) for non-Federal operations.7 The U-NII-2A band is allocated on a primary basis to the
Earth Exploration Satellite (active), Radiolocation, and Space Research (active) Services for Federal
operation, and for non-Federal operation on a secondary basis.8
6.
The U-NII-2C band is allocated on a primary basis to the Radiolocation Service for
Federal operation. The sub-band at 5.47-5.65 GHz band is allocated on a primary basis to the
Radiolocation Service for non-Federal operation, and on a primary basis to the Maritime Radionavigation
Service for both Federal and non-Federal operations. The 5.47-5.570 GHz band segment is allocated on a
primary basis to the Earth Exploration-Satellite (active) and Space Research (active) Services for Federal
operation and on the secondary basis for non-Federal operation. The 5.6-5.65 GHz band segment is
allocated on a primary basis to the Meteorological Aids Service for both Federal and non-Federal
operations. The band segment at 5.65-5.725 GHz is allocated on a secondary basis to the Amateur Radio
Service for non-Federal operation.9
7.
The U-NII-3 band is allocated on a primary basis to the Radiolocation Service for Federal
operation, and is allocated on a secondary basis to the Amateur Radio Service for non-Federal operation.10
8.
In early 2009, Federal Aviation Administration (FAA) reported interference to their
Terminal Doppler Weather Radar (TDWR) that operates within the 5.60-5.65 GHz band. Early field
studies performed by the National Telecommunications and Information Administration’s (NTIA’s)
Institute for Telecommunications Sciences (ITS) and FAA staff indicated the interference sources were

5 See Amendment of the Commission’s Rules to Provide for Operation of Unlicensed NII Devices in the 5 GHz
Frequency Range, Report and Order, ET Docket No. 96-102, 12 FCC Rcd 1576 (1997). (U-NII Report and Order).
See 47 C.F.R. Part 15 Subpart E. In this NPRM, we have assigned sequential numbers to identify the 5 GHz band
segments, both the current U-NII bands and future potential U-NII bands, which are discussed below. We recognize
that different organizations, both Federal and non-Federal, have used a variety of different identifiers for these band
segments, but we have chosen sequential numbering to make it easier for the reader to follow the discussion in the
NPRM.
6 See Revision of Parts 2 and 15 of the Commission’s Rules to Permit Unlicensed National Information
Infrastructure (U-NII) devices in the 5 GHz band, Report and Order, ET Docket No. 03-122, 18 FCC Rcd 24484
(2003). In this decision, the Commission also required that U-NII devices in the U-NII-2A and U-NII-2C bands
employ dynamic frequency selection (DFS) to protect Federal radar operations and transmit power control (TPC) to
protect the Earth exploration satellite service. See 47 C.F.R § 15.407(h).
7 See 47 C.F.R. § 2.106, Table of Frequency Allocations.
8 Id.
9 Id.
10 Id.
3

Federal Communications Commission

FCC 13-22

unlicensed U-NII devices that incorporated dynamic frequency selection (DFS),11 from different
manufacturers, and operated in the same frequency band as these Federal radar systems.
9.
The Commission brought together all of the principal parties including NTIA, FAA,
industry participants and the FCC’s Enforcement Bureau and Office of Engineering and Technology to
analyze the interference situation. Based on these investigations, the Commission has taken actions to
mitigate the interference situation, including issuing enforcement advisories to heighten users’ awareness
of TDWR interference issues,12 and the Office of Engineering and Technology has placed conditions on
U-NII device certifications to curtail the interference risk. The Commission also has sent enforcement
teams to work with FAA staff in the field, and has taken enforcement actions against operators of U-NII
devices that caused interference to TDWR installations including issuing Letters of Inquiry and Notices of
Apparent Liability for Forfeitures to operators found to be causing interference.13 Most of these
interference cases were caused by devices not certified for operation in the U-NII-2C band, which
includes the 5.6-5.65 GHz band used by the TDWRs. Instead, these devices had been certified for
operation in the U-NII-3 band, either as U-NII devices under Section 15.407 of our rules or as digitally
modulated intentional radiators under Section 15.247 of our rules, and which were operating at high
power levels in elevated locations. The Commission’s investigations found that most U-NII devices are
manufactured to enable operation across a wide range of frequencies, extending down into the 4-GHz
bands and up to almost 6 GHz. In many cases, the interference was caused by third parties modifying
software configurations to enable operation in frequency bands other than those for which the device had
been certified but without meeting the technical requirements for operation in those frequency bands.
There was also an issue with devices that employed frame based architectures that allowed operators to
reconfigure the talk/listen ratio of their devices.
10.
In 2006 the Commission issued measurement procedures that it would use to test the
devices to ensure that they comply with the radar detection and the dynamic frequency selection (DFS)
requirements for the U-NII-2A and U-NII-2C bands.14 In response to the TDWR interference cases,

11 DFS is a mechanism that detects the presence of radar signals and dynamically guides a transmitter to switch to
another channel whenever a particular condition is met. Prior to the start of any transmission, a U-NII device
equipped with DFS capability must continually monitor the radio environment for radar’s presence. If the U-NII
device determines that a radar signal is present, it must either select another channel to avoid interference with radar,
or go into a “sleep mode” if no other channel is available.
12 See FCC Enforcement Advisory, TDWR and U-NII Devices, “Enforcement Bureau Takes Action to Prevent
Interference to FAA-Operated Terminal Doppler Weather Radars Critical to Flight Safety,” (TDWR Enforcement
Advisory) DA 12-459, September 27, 2012, Enforcement Advisory No. 2012-07, available at:
http://www.fcc.gov/encyclopedia/weather-radar-interference-enforcement. Users of U-NII devices include wireless
Internet service providers (WISPs), which were the focus of the Enforcement Advisory for outdoor fixed
installations, as well as consumers for indoor wireless networking.
13 See VPNet, Inc., Notice of Apparent Liability for Forfeiture and Order, 27 FCC Rcd 2879 (Enf. Bur. 2012); Argos
Net, Inc.
, Notice of Apparent Liability for Forfeiture and Order, 27 FCC Rcd 2786 (Enf. Bur. 2012); Insight
Consulting Group of Kansas City, LLC
, Notice of Apparent Liability of Forfeiture and Order, 26 FCC Rcd 10699 (Enf.
Bur. 2011); Ayustar Corp., Notice of Apparent Liability for Forfeiture and Order, 26 FCC Rcd 10693 (Enf. Bur.
2011); Rapidwave, LLC, Notice of Apparent Liability for Forfeiture and Order, 26 FCC Rcd 10678 (Enf. Bur.
2011); AT&T, Inc., Notice of Apparent Liability for Forfeiture, 26 FCC Rcd 1894 (Enf. Bur. 2011); Utah
Broadband
, Notice of Apparent Liability for Forfeiture, 26 FCC Rcd 1419 (Enf. Bur. 2011) (forfeiture paid). See
also Ayustar Corp.
, Memorandum Opinion and Order, 25 FCC Rcd 16,249 (Enf. Bur. 2010); Sling Broadband, LLC,
Forfeiture Order, 26 FCC Rcd 13062 (Enf. Bur. 2011).
14 These procedures were based on the work of the International Telecommunication Advisory Committee-
Radiocommunication (ITAC-R) Government/Industry Project Team (Project Team) /Industry Project Team (Project
Team) and recommendations from NTIA. See Letter from Fredrick R. Wentland, Associate Administrator, NTIA to
Julius Knapp, Deputy Chief, OET, filed in ET Docket No. 03-122 on March 30, 2006, and the enclosure
(continued....)
4

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FCC 13-22

NTIA and the Federal Aviation Administration (FAA) have recently recommended to the Commission
that the 2006 compliance and measurement procedures for DFS be revised15to include modified
definitions, technical requirements (e.g., detection bandwidth and pulse repetition interval values), radar
test waveforms, test procedures, and test report guidelines.
11.
In recent years, there has been an industry wide push to increase the amount of spectrum
available for unlicensed use. In June 2010, the President issued an Executive Memorandum that
encouraged the Commission to work closely with the Department of Commerce, through NTIA, to make
available a total of 500 megahertz for commercial mobile and fixed wireless broadband use by the year
2020.16 The FCC’s 2010 National Broadband Plan recommended that the Commission make available
500 megahertz of new spectrum for wireless broadband within 10 years.17 In analyzing the need for
broadband spectrum, the Commission also concluded that nearly 300 megahertz of spectrum is needed by
2014, and that making available additional spectrum for mobile broadband would create value in excess
of $100 billion through avoidance of unnecessary costs.18
12.
In addition, Congress has enacted legislation that addresses unlicensed use of the 5 GHz
band. The Spectrum Act requires the Commission to begin a proceeding to modify Part 15 of the title 47,
Code of Federal Regulations (CFR), to allow unlicensed U-NII devices to operate in the 5.35-5.47 GHz
band (referred to hereinafter as U-NII-2B) no later than 1 year after the date of the enactment of the Act19
if, in consultation with the Assistant Secretary of Commerce (i.e., the NTIA Administrator), it determines
that licensees will be protected by technical solutions and that the primary mission of Federal spectrum
users in the band will not be compromised by the introduction of unlicensed devices in this band.20
13.
The Spectrum Act also requires NTIA, in consultation with the Department of Defense
and other impacted agencies, to conduct a study evaluating known and proposed spectrum sharing
technologies and the risks to Federal users if unlicensed U-NII devices were allowed to operate in the U-

(...continued from previous page)
Compliance Measurement Procedures for Unlicensed National Information Infrastructure Devices Operating in the
5250-5350 MHz and 5470-5725 MHz bands Incorporating Dynamic Frequency Selection (Compliance
Measurement Procedures)
. See also Revision of Parts 2 and 15 of the Commission’s Rules to permit Unlicensed
National Information Infrastructure (U-NII) devices in the 5 GHz Band, Memorandum Opinion and Order, ET
Docket No.03-122,21 FCC Rcd 7672 Appendix Compliance Measurement Procedures for Unlicensed-National
Information Infrastructure Devices Operating in the 5250-5350 MHz and 5470-5725 MHz Bands Incorporating
Dynamic Frequency Selection.
15 See Letter from Lawrence E. Strickling, Administrator, NTIA to Julius Genachowski, Chairman, FCC, filed
February 19, 2013, and the enclosure Appendix - Proposal for New Unlicensed National Information Infrastructure
Dynamic Frequency Selection Certification Waveforms.
A copy of this document has been placed in the docket file
for this proceeding.
16 See Presidential Memorandum: Unleashing the Wireless Broadband Revolution (Executive Memo) (June 28,
2010), available at: http://www.whitehouse.gov/the-press-office/presidential-memorandum-unleashing-wireless-
broadband-revolution.
17 FCC, Connecting America: The National Broadband Plan at Chapter 5, available at: http://www.broadband.gov.
18 See Omnibus Technical Report, Mobile Broadband: The Benefits of Additional Spectrum (Oct. 2010), pg 18,
available at: http://download.broadband.gov/plan/fcc-staff-technical-paper-mobile-broadband-benefits-of-
additional-spectrum.pdf. While the statements in the paper were aimed at unleashing 300 megahertz of licensable
spectrum, unlicensed spectrum has the potential to ease the strain of the spectrum deficit. Unlicensed wireless
networks operating in the U-NII bands help to decrease the demands on mobile cellular providers that use mobile
data offloading. Mobile data offloading is the process by which data that would normally be transmitted over the
cellular network is rerouted to complementary networks. For cellular phones and smart phones in particular, the
offloaded data is typically routed over unlicensed wireless networks. This decreases the traffic load and helps to
alleviate the congestion created by increased broadband data use on the cellular networks.
5

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FCC 13-22

NII-2B band as well as in the 5.85-5.925 GHz band (referred to hereinafter as U-NII-4). NTIA was
required to publish a report on the U-NII-2B band no later than 8 months after the date of enactment of
the Spectrum Act and a report on the 5.85-5.925 GHz band (referred to hereinafter as U-NII-4) no later
than 18 months after the date of enactment of the Spectrum Act. NTIA published a report (hereinafter
referred to as “NTIA 5 GHz Report”) on both the U-NII-2B and U-NII-4 bands on January 25, 2013.21
14.
The chart below summarizes the frequency bands for U-NII device operation that are
discussed in the NPRM. The chart also indicates that unlicensed devices may be authorized to
operate in the U-NII-3 band, as well as the 25 megahertz between that band and the potential future
U-NII-4 band, under the digital modulation rules in Section 15.247.
z

U-NII-

NII 3

H

(100 MHz)

New Band

New Band

U-

U NII-1

-

U-NII-

NII 2A

U-

U NII-2C

2
5

M

U-

U NII-2B

-

U-NII-4

-
(100 MHz)
(100 MHz)
(255 MHz)
(120 MHz)

Part 15.247 Rules

(120 MHz)
(75 MHz)
(125 MHz)
5.150GHz
5.250GHz
5.350GHz
5.470GHz
5.725GHz
5.850GHz
5.925GHz

III.

DISCUSSION

15.
Wireless broadband services are in high demand by the public and that demand is
expected to grow significantly in the coming years. Increasingly, U-NII devices have played a role in
meeting some of that demand, particularly U-NII devices used for wireless local area networking and
broadband access. The U-NII bands hold significant promise for helping to accommodate the needs of
businesses and consumers for fixed and mobile broadband communications, and thus it is important that
we explore fully ways to reduce significantly the potential for interference to authorized users of the 5
GHz band that arise from U-NII operations.
16.
The Commission’s U-NII rules were developed to address the particular sharing
scenarios presented by each frequency band. For example, devices in the U-NII-1 band operate only
indoors and at very low power (50 mW); devices in the U-NII-2A and U-NII-2C bands may operate either
indoors or outdoors at higher power (250 mW) but must deploy dynamic frequency selection (DFS) to
protect incumbent radar operations and transmit power control (TPC) to protect the Earth exploration–
satellite service; and devices in the U-NII-3 band may operate either indoors or outdoors at even higher
power (1 W).22 A U-NII device uses radar detection along with DFS in the U-NII-2A and U-NII-2C
bands to monitor the spectrum and operate only on frequencies not already in use by Federal radar
systems.23 TPC is used in the U-NII-2A and U-NII-2C bands to further protect operations in the Earth

(...continued from previous page)
19 See supra note 3 at Section 6406(a).
20 Id. The Spectrum Act states that technical solutions may include existing, modified or new spectrum-sharing
technologies and solutions, such as dynamic frequency selection.
21 See Department of Commerce, “Evaluation of the 5350-5470 MHz and 5850-5925 MHz Bands Pursuant to
Section 6406(b) of the Middle Class Tax Relief and Job Creation Act of 2012,” available at
http://www.ntia.doc.gov/files/ntia/publications/ntia_5_ghz_report_01-25-2013.pdf. A copy of this report has been
placed in the docket of this proceeding.
22 A chart displaying the different technical requirements for each band is provided in Appendix C.
23 Before starting any transmission, a U-NII device equipped with DFS capability must continually monitor the radio
environment for the presence of a radar system. If the U-NII device determines that a radar system is present, it
must either select another channel or enter a “sleep mode” if no channels are available. See 47 C.F.R. §§ 15.403(g)
and 15.407(i).
6

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Exploration-Satellite Service (active) (EESS) and the Space Research Service (active) (SRS) from
harmful interference.24
17.
Over time, we have gained considerable experience with U-NII devices operating in each
of these bands as both indoor and outdoor uses have evolved and increased. Based on this experience, we
have identified issues that we need to address so that the spectrum in the 5 GHz band can continue to
provide much needed support for broadband and other wireless services while protecting authorized
operations. In particular and as described above, we have seen an increase in interference incidences in
U-NII bands that are caused by users unlawfully modifying and operating unlicensed devices that have
not been certified to meet the required technical rules for these bands. This type of conduct occurs mainly
because devices are designed and manufactured that are capable of operating over a wide swath of
frequencies, and only the software configuration of these devices limits their operation to permissible
bands or operational parameters that comply with the Commission’s rules. Also, unlicensed devices in
the U-NII-3 band and above can be authorized under two different sets of rules as either spread spectrum
devices or U-NII devices, which introduces complexity in the compliance testing process and also permits
an uneven playing field for band sharing with authorized services.25
18.
There are other forces at work that make this an opportune time for the Commission to
re-examine the U-NII rules. A new Wi-Fi standard—IEEE 802.11ac that is expected to be finalized in the
near future—would allow for wider bandwidth transmissions by devices that would operate over more
than one U-NII band, thus increasing use of the band for broadband services.26 Also, the amount of
contiguous spectrum available for U-NII devices may increase as we, in conjunction with NTIA,
investigate opening the U-NII-2B and U-NII-4 bands to these devices. Both of these circumstances
present exciting opportunities for new unlicensed uses of the 5 GHz band. Three sets of Wi-Fi standards
are used for the 5 GHz U-NII bands: 802.11a, 802.11n and 802.11ac. Each standard specifies different
channel bandwidths and data rates. For example, the 802.11a standard defines a 20 megahertz channel
bandwidth with maximum data rate up to 54 Mbit/s,27 and the 802.11n standard specifies 20 and 40
megahertz channel bandwidths with maximum data rate from 54 Mbit/s to 600 Mbit/s.28 The new
802.11ac standard would allow for a significant increase in bandwidth and data rates in the 5 GHz band—
it specifies bandwidths of 20, 40, 80, and 160 megahertz with a link data rate of approximately 1 Gbit/s.29

24 TPC is a feature that adjusts a transmitter’s output power based on the signal level present at the receiver. As the
signal level at the receiver rises or falls, the transmit power will decrease or increase as needed. Therefore, TPC will
cause the transmitter to operate at less than the maximum power when lower signal levels can provide acceptable
quality of service. See 47 C.F.R. § 15.407(h).
25 See infra para. 23.
26 See www.Wi-Fi.org. How does Wi-Fi technology work? Wi-Fi is a short range technology that is often used in
conjunction with a customer’s DSL, FIOS, or cable modem service to connect end-user devices, such as PCs,
laptops and smart phones, located within the customer’s home or business to the Internet. In these cases, Wi-Fi
allows users to move Wi-Fi enabled devices around within their homes or businesses without installing additional
inside wiring, but the actual ”connection” to the service provider is via the customer’s DSL, FIOS, or cable modem
service. Wi-Fi is widely available in airports, city parks, restaurants, bookstores and other public places called
“hotspots,” allowing those who are away from their homes or businesses to access the Internet.
27 The 802.11a standard is an amendment to the original standard that was ratified in 1999. The amendment was
incorporated into the published IEEE 802.11-2007.
28 IEEE 802.11n is an amendment to the IEEE 802.11-2007 standard and was published in 2009.
29 At the time of writing this document, the 802.11 ac standard is still under development. The IEEE 802.11ac
standard is expected to be finalized in February 2014. See
http://grouper.ieee.org/groups/802/11/Reports/802.11_Timelines.htm.
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19.
The current U-NII bands can easily accommodate implementation of the new 802.11ac
standard. For example, 160 megahertz channels do not need to rely on contiguous spectrum, and a single
transmission can aggregate multiple smaller channels by simultaneously transmitting in different bands.
The current U-NII bands can accommodate two 160 megahertz high-speed channels, and, if additional 5
GHz spectrum is made available for U-NII devices, would provide for five high-speed channels.
However, each U-NII band presents its own sharing challenges, and thus the technical and operational
requirements for U-NII devices are not consistent across the 5 GHz band. We should strive to provide as
much consistency in our rules as possible so that wide bandwidth U-NII devices operating across multiple
bands are not driven to comply with the most restrictive requirements for any one band and forfeit
opportunities for new broadband applications that may be permitted in other bands.
20.
In this NPRM, we take the first steps towards ensuring the U-NII bands continue to meet
the demand for broadband spectrum, while ensuring protection of authorized operations, by proposing
modifications to the Part 15 rules. In particular, we are proposing to align the provisions for operation of
digitally modulated devices in the 5.725-5.85 GHz band, now permitted under Section 15.247 of our
rules,30 with the rules for the U-NII-3 band under Section 15.407. This will expand the U-NII-3 band by
25 megahertz and provide consistent rules across 125 megahertz of spectrum. We also seek comment on
aligning the power limits and permissible location for operations in the U-NII-1 and U-NII-2A bands to
permit the introduction of a new generation of wireless devices in 200 megahertz of contiguous spectrum.
21.
We also address ways to ensure compliance with our rules across all of the U-NII bands
and, in particular, the U-NII-2A and U-NII-2C bands to curtail interference to incumbent Federal
operations (e.g. TDWR installations). We seek comment on various ways to prevent unlawful
modification and operation of unlicensed devices in the U-NII bands as well as compliance issues that are
likely to arise as we move toward wider bandwidth systems operating across multiple U-NII bands.
Although some of the methods discussed below would ensure that manufacturers and users comply with
the Commission’s requirements across any of the U-NII band segments, we also seek comment on some
techniques that may be useful mainly in curtailing interference to incumbent Federal operations, such as
TDWR installations, in the U-NII-2A and U-NII-2C bands, such as geo-location and database
registration, unwanted emissions limits, and guard band requirements. We also seek comment on several
issues specific to the U-NII-2A and U-NII-2C bands regarding DFS functionality, the sensing threshold
for co-channel operation, and revised DFS measurement procedures. We ask that commenters address the
benefits of adopting any of the proposals in the NPRM as well as the costs to do so, and that they weigh
and compare the benefits and costs in each case. This assessment should address which costs should be
borne by U-NII device manufacturers, U-NII device operators or other third parties, as appropriate.
22.
In this NPRM, we also seek comment on modifying Part 15 Subpart E of the
Commission’s rules governing the operation of U-NII devices to make available an additional 195
megahertz of spectrum in the 5.350 – 5.470 GHz (U-NII-2B) and 5.850 – 5.925 GHz (U-NII-4) bands.
This would increase the spectrum available to unlicensed devices in the 5 GHz band by nearly 35 percent
and would represent a significant increase in spectrum available for unlicensed operations. Finally, we
seek comment on transition periods for requiring compliance with any modified rules that we ultimately
adopt in this proceeding.

A.

The Current U-NII Bands

1.

Unlicensed Operations in the U-NII-3 Band

23.
Background. Prior to the adoption of the DFS requirements for U-NII devices in the U-
NII-2A and U-NII-2C bands in 2003, the Commission amended Part 15 to provide for the introduction of
digital transmission technologies and to improve spectrum sharing by unlicensed devices operating under

30 See 47 C.F.R. §15.247.
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the provisions of Section 15.247 of its rules.31 Specifically, the Commission revised Section 15.247 to
allow new digital transmission technologies and direct sequence spread spectrum systems to operate
under the same rules in the 5.725-5.85 GHz band.32 The Commission noted that the permitted uses under
Section 15.247 were similar to the rules for U-NII devices in the U-NII-3 band and sought comment on
whether these new digital technologies could be accommodated under the U-NII rules. The Commission
recognized that in order to accommodate the proposed digital devices under the U-NII rules, the upper
limit of the U-NII-3 band would need to be extended 25 megahertz to 5.85 GHz to align the requirements
with those permitted under Section 15.247. The Commission declined to modify the U-NII rules and
determined that digitally modulated devices were best accommodated under Section 15.247 for digitally
modulated systems.33 Consequently, digital devices are permitted to operate in the 5.725 – 5.85 GHz
band under Section 15.247 rules as well as in the 5.725 – 5.825 GHz band under the U-NII rules in
Section 15.407. Thus, our rules permit manufacturers to examine the different technical requirements for
digitally modulated devices in Section 15.247 and the U-NII rules in Section 15.407 to determine which
requirements are best suited for a particular 5.7 GHz digital device.
24.
The primary differences between the two rule sections are that 25 megahertz of spectrum
covered by Section 15.247 are not part of the U-NII rules and that point-to-point devices authorized under
Section 15.247 are permitted higher power based on increasing antenna gain. Although the total
conducted power levels for Section 15.247 and U-NII-3 devices are the same (1 W), the radiated power
levels permitted under Section 15.247 are higher for point-to-point operations because we do not apply a
power penalty for high antenna gain. In general, the power spectral density (PSD) limit under Section
15.247 is higher (8 dBm/3 kHz, which is equivalent to 33 dBm/MHz) 34 than the power spectral density
limit for U-NII-3 devices (17 dBm/MHz).35 In addition, while we use an absolute unwanted emissions
limit of -17 dBm/MHz for the U-NII-3 devices, the unwanted emissions limit for Section 15.247 devices
is a function of the in-band power which could be as much as 33 dBm higher than that of a U-NII-3
device.36 Finally, the unwanted emission limits from Section 15.247 require emissions in all restricted
frequency bands to meet the Section 15.209 general emission limits, while Section 15.407 requires all
emissions below 1 GHz to meet the Section 15.209 general emission limits. The result of this rule
disparity is that manufacturers are opting to certify devices under Section 15.407 for the U-NII-1, U-NII-

31 See Amendment of Part 15 of the Commission’s Rules Regarding Spread Spectrum Devices, Second Report and
Order
, ET Docket No. 99-231, 17 FCC Rcd 10755 (2002) (Spread Spectrum Second Report and Order).
32 Id. Spread spectrum modulation reduces the power density of the transmitted signal at any frequency, thereby
reducing the possibility of causing interference to other signals occupying the same spectrum. Similarly, at the
receiver end, the power density of interfering signals is minimized, making spread spectrum systems relatively
immune to interference from outside sources. In frequency hopping spread spectrum (FHSS) systems, an
information signal, usually a data stream, modulates a radio frequency carrier that quickly moves from frequency to
frequency in concert with a receiver. In direct sequence spread spectrum (DSSS) systems, the information data
stream is combined with a high speed digital spreading code that is used to modulate a radio carrier, producing a
radio signal that has a bandwidth covering anywhere from 0.5 to hundreds of megahertz. See also 47 C.F.R. §
2.1(c). Digital systems spread their transmitted energy across a wide bandwidth, thereby minimizing the amount of
energy transmitted in any one portion of the occupied frequency band. Therefore, such digital modulation systems
may exhibit no more potential to cause interference to other devices than direct sequence systems. However,
because digital modulation systems do not meet the Commission’s definition of a spread spectrum system, the rules
were amended in 2002 to allow their operation under the Section 15.247 rules, which had previously allowed for
only FHSS and DSSS systems.
33 See Spread Spectrum Second Report and Order at 10761.
34 See 47 C.F.R. §15.247(e).
35 See 47 C.F.R. § 15.407(a)(2).
36 See 47 C.F.R. §15.247(c).
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2A and U-NII-2C frequency bands, but opting to certify devices operating in the U-NII-3 band under
Section 15.247 in order to access more spectrum and use higher PSD levels.
25.
This rule disparity has led to several difficulties in managing digital devices in the 5.725
– 5.85 GHz band. For example, the introduction of devices capable of operating across multiple frequency
bands and under different rule parts introduces complexity to the equipment authorization process.37 In
addition to the complexity in equipment authorization, our investigation of interference complaints has
shown that equipment is often designed and manufactured in a way that the devices are able to operate
over a swath of frequencies much wider than the bands in which they are certified to operate. This
hardware capability is sometimes exploited by third parties who modify the device software to enable
operation across more frequency bands without the device being certified to meet the technical rules
necessary for operation in those other frequency bands. Most frequently we have seen devices certified to
operate in the 5.725-5.85 GHz band with higher power levels and later modified to enable operation in the
U-NII-2 frequency bands. These device modifications have resulted in non-compliant devices creating
interference scenarios that were not anticipated when the U-NII rules were created.
26.
Discussion. We believe that now is an appropriate time to review our rules to eliminate
the disparity and decrease the complexity associated with interpreting our rules for digitally modulated
devices operating in the U-NII-3 band under Section 15.407 and in the 5.725 – 5.85 GHz band under
Section 15.247 We believe the changes we propose below will ensure compliance with requirements
designed to protect authorized services in the U-NII bands, simplify our authorization procedures, and
reduce certification cost for manufacturers of these devices. The spectrum ecosystem has changed
considerably since the Commission allowed the certification of “digitally modulated” devices. For
example, the standards for wireless broadband devices are now capable of producing data rates in excess
of 1 Gbits/s. In addition, devices are now able to utilize advances in antenna technology that allow the
multiple data streams to be transmitted over multiple antennas. This provides an opportunity for us to
reflect on recent industry developments and propose new rules that have the potential to increase
consistency in the process of certifying 5 GHz wireless broadband devices, while continuing to protect
authorized services.
27.
As we discuss in more detail below, we are proposing two changes that will eliminate the
disparity in our rules for 5.7 GHz digitally modulated devices. First, we propose to extend the upper edge
of the U-NII-3 band from 5.825 GHz to 5.85 GHz to match the amount of spectrum available for digitally
modulated devices under Section 15.247. We believe that this change would eliminate the complexity
and costs associated with multiple rule part certifications for these devices which are technically similar.
Adopting this proposal would not increase the potential for harmful interference because this 25
megahertz segment is already available for devices certified under Section 15.247. We seek comment on
the potential benefits of expanding the U-NII-3 band to include an additional 25 megahertz of spectrum at
the upper band edge. We invite comment on whether there are cost advantages of this proposal. We ask
that commenter’s assessment of adopting the proposal weigh and compare the benefits and costs to do so.
This assessment should address which costs should be borne by U-NII device manufacturers, U-NII
device operators or other third parties, as appropriate.

37 In addition to higher emissions limits, the measurement procedures for Sections §15.247 and §15.407 vary
considerably. The FCC’s Lab has issued guidance through its knowledge data base program (KDBs) for testing of
emissions for compliance with Sections 15.247 and the U-NII device rules in Sections 15.401 through 15.407. See
KDB 644545 D01 – Guidance for IEEE 802.11ac and Pre-ac Device Emission Testing and KDB 644545 D02
Alternative Guidance for IEEE 802.11ac and Pre-ac Emissions Testing. These KDB documents are available at:
www.fcc.gov/labhelp. The alternative guidance permits all emissions testing for operation between 5.725 and 5.85
GHz to be performed using testing procedures for U-NII devices and emission limits based on the U-NII rules at
Section 15.407 even though operations may extend above the 5.825 GHz upper bound of the U-NII-3 band. We
discuss compliance issues for composite devices more fully in Section III. B., below.
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28.
Second, we propose to consolidate all equipment authorizations for digitally modulated
devices in the 5.725-5.85 GHz band under the U-NII rules, while maintaining many of the technical rules
that currently make equipment authorization under Section 15.247 more attractive for equipment
manufacturers. We also propose to remove the 5.725-5.85 GHz band for digital modulation devices from
Section 15.247. By doing this, we will ensure that all digitally modulated equipment, which is technically
similar, operates under a single rule part using identical technical rules.38 We propose to modify Section
15.407 for digitally modulated devices as discussed below, and we seek comment on all of these proposed
rule changes. We invite comment on the benefits of adopting any of the proposed rule changes below as
well as the costs to do so. We ask that commenter’s assessment of adopting the proposals weigh and
compare the benefits and costs to do so. This assessment should address which costs should be borne by
U-NII device manufacturers, U-NII device operators or other third parties, as appropriate.
29.
Frequency Band. Section 15.247 allows operation throughout the 5.725-5.85 GHz band,
while Section 15.407 allows operation only in the 5.725-5.825 GHz band. The extra 25 megahertz of
spectrum that is allowed under Section 15.247 provides incentive for device manufacturers to certify
devices under that rule rather than under Section 15.407. We propose to expand the frequency band of
operation in Section 15.407 to include the 5.825-5.85 GHz band. This will allow U-NII-3 devices to
operate across the full range of spectrum that can currently be accessed by digitally modulated devices
under Section 15.247.
30.
Power. Section 15.247 allows 1 Watt of total peak conducted power (alternate
measurement procedures are permitted), whereas Section 15.407 limits maximum conducted output
power to the lesser of 1 Watt or 17 dBm + 10 log B (in MHz, alternate measurement procedure in Section
15.247 is required).39 In addition to the 1 watt power limit, there is a separate PSD limit in both Sections
15.247 and 15.407 such that 1 Watt of total power is available only when the 6-dB bandwidth is 500
kilohertz or more under Section 15.247 and when the 26-dB bandwidth is 20 megahertz or more under
Section 15.407.40 Because we are trying to accommodate digitally modulated devices that are currently
permitted under both rules, we propose to remove the bandwidth dependent term (i.e., remove 17 + 10 log
B) from Section 15.407 so that the power limit will be 1 Watt. We do not believe removing the variable
power limit in 15.407 would increase any potential for interference, because under current rules
manufacturers are able to certify equipment that uses up to 1 Watt of power under Section 15.247.
31.
Power Spectral Density. Section 15.247 requires a maximum PSD of 8 dBm/3 kHz (33
dBm/MHz), whereas Section 15.407 requires a maximum PSD of 17 dBm/MHz. The only difference
between these two PSD limits is the bandwidth at which the 1 Watt total power, rather than the PSD,
becomes the limiting factor. Specifically, Section 15.247 allows a higher PSD when the device emission
bandwidth is between 0.5 to 20 megahertz. Above 20 megahertz emission bandwidth, the 1 Watt power
limit becomes the limiting parameter, and PSD is the same for both Sections 15.247 and 15.407. We
propose to modify Section 15.407 to require the PSD limit used in Section 15.247 (i.e., 8 dBm/3 kHz (33
dBm/MHz)), so that digitally modulated devices designed to meet this limit will continue to comply with
the new PSD requirement in Section 15.407. This will ease the transition of all digitally modulated
devices in the 5.725-5.85 GHz band to authorization and compliance under Section 15.407. The only

38 We would continue to authorize under Section 15.247 frequency hopping spread spectrum devices in the 5725-
5850 MHz band and hybrid devices, i.e., those that can function as either spread spectrum or digitally modulated
systems because these devices have not been observed to cause interference to TDWRs and do not have the
similarities to U-NII devices that other digitally modulated systems have.
39 See 47 C.F.R. §§ 15.247(b)(3) and 15.407(a)(3). See also KDB 644545 D01 – Guidance for IEEE 802.11ac and
Pre-ac Device Emission Testing and KDB 644545 D02 Alternative Guidance for IEEE 802.11ac and Pre-ac
Emissions Testing. These KDB documents are available at: www.fcc.gov/labhelp.
40 See 47 C.F.R. §§ 15.247(e) and 15.407(a)(3).
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change for digitally modulated devices will occur when emission bandwidth is between 500 kilohertz and
20 megahertz. High-bandwidth devices like those typically used in U-NII applications will still be
limited by 1 Watt total power, and thus the proposed change in PSD limits would not increase the risk of
any potential interference. However, we do realize that limiting the PSD to 8dBm/kHz (33dBm/MHz)
would result in a PSD that is higher than the total power limit of 1 watt (30dBm). In addition, we realize
that requiring devices that employ wider bandwidths to utilize a measurement bandwidth of 3 kHz may
unnecessarily increase the time that it takes to complete measurement tests. We seek comment on
whether we should increase the measurement bandwidth to 1 megahertz to reduce the complexity in
measurement tests. We note that changing the measurement bandwidth would promote consistency
within the U-NII rules. Should we consider implementing a different PSD limit and measure this limit
across differing bandwidths, e.g. 500 kHz or 100 kHz measurement bandwidths?
32.
Emission Bandwidth. Section 15.247 requires a minimum 6-dB bandwidth of 500
kilohertz. No minimum or maximum bandwidth is required under Section 15.407, but the emission
bandwidth is defined and measured as the 26-dB down points of the U-NII signal and is used to determine
the total power allowed under that rule. Because we are proposing to eliminate the bandwidth-dependent
limit on total power, we propose to modify Section 15.407 to eliminate the 26-dB bandwidth requirement
and to add the minimum 6-dB bandwidth requirement from Section 15.247.
33.
Antenna Gain. Under Section 15.247, the assumed antenna gain is 6 dBi, with a 1 dB
reduction in power required for every 1 dB that the antenna gain exceeds 6 dBi. For fixed point-to-point
systems, no power reduction is required. Section 15.407 assumes the same antenna gain of 6 dBi, with 1
dB reduction in power required for every 1 dB that gain exceeds 6 dBi. For fixed point-to-point systems,
a 1 dB reduction in power is required for every 1 dB that gain exceeds 23 dBi. The only difference
between the two rule parts is the maximum antenna gain that can be deployed without a penalty in
transmitter power. We propose to apply the more stringent 23 dBi maximum antenna gain that is
currently required under Section 15.407. We believe that using the more stringent antenna gain
requirement will ensure that there is no increase in the potential for interference from unlicensed devices
operating under the new combined rule parts.
34.
Unwanted Emissions. Section 15.247(d) requires 20 dB of attenuation (30 dB if the
alternate measurement procedure detailed in Section 15.247(b)(3) is used). In restricted bands,41
emissions must meet the Section 15.209 general emission limits.42 Section 15.407 requires unwanted
emissions to be below -17 dBm/MHz within 10 megahertz of the band edge, and below -27 dBm/MHz
beyond 10 megahertz of the band edge.43 Also, all emissions below 1 GHz must comply with the Section
15.209 general emission limits. The unwanted emission limits in Section 15.407 are somewhat more
restrictive than those in Section 15.247. Because unwanted emission can be reduced without affecting the
utility of the device, and because using the more stringent unwanted emissions requirement will ensure
that there is no increase in the potential for interference from unlicensed devices operating under the new
combined rule parts, we are proposing that the more restrictive limits in Section 15.407 be required for
digitally modulated devices.

41 See 47 C.F.R. § 15.205(a). There are a number of restricted bands in which low power, non-licensed transmitters
are not allowed to operate because of potential interference to sensitive radio communications such as aircraft
radionavigation, radio astronomy and search and rescue operations. Only spurious emissions from Part 15 devices
are permitted in these restricted bands.
42 See 47 C.F.R. § 15.247(d). See also 47 C.F.R § 15.209.
43 In KDB 789033 D01– UNII General Test Procedures v01r02 (available at: http://www.fcc.gov/labhelp) , our
Office of Engineering and Technology (OET) has advised applicants that they can demonstrate compliance with the
-27 dBm/MHz and -17 dBm/MHz out-of-band emission limits outside of the restricted bands with spectrum
measurements performed with the peak detection and “max hold” settings of the spectrum analyzer.
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35.
Peak to Average Ratio. Section 15.407 contains a requirement to maintain a peak-to-
average ratio of no more than 13 dB across any 1 megahertz band, whereas Section 15.247 does not
contain any peak-to-average ratio requirement. We believe that using the more stringent peak-to-average
requirement will ensure that there is no increase in the potential for interference from unlicensed devices
operating under the new combined rule parts, thus we are proposing to keep the peak-to-average ratio
requirement that is currently in Section 15.407.
2.

Unlicensed Operations in the U-NII-1 Band

36.
Background. The U-NII-1 band is one of the first 5 GHz band segments made available
for U-NII devices in 1997.44 The frequency band is allocated on a primary basis for Federal and non-
Federal Aeronautical Radionavigation and non-Federal Fixed Satellite Service (FSS) (Earth-to-space) to
provide feeder links for non-geostationary orbit (NGSO) satellite systems in the Mobile Satellite Service
(MSS).45 The Commission adopted technical rules for U-NII devices in this band to protect the nascent
NGSO/MSS industry which had gained an international FSS allocation at 5 GHz in 1995.46 Specifically,
the Commission adopted a peak transmitter output power limit of 50 mW with up to 6 dBi antenna gain
permitted, which equates to 200 mW EIRP, and a transmitter peak power spectral density of 2.5
mW/MHz (4 dBm/MHz) for the same 6 dBi antenna gain. The Commission believed that a 50 mW peak
output power with up to 6 dBi gain antenna would provide U-NII devices with sufficient flexibility in
using the band. The Commission also restricted U-NII devices to indoor operation to provide additional
protection to co-channel NGSO/MSS operations. The Commission determined that the low power limits
would allow U-NII devices to provide a variety of short-range communications within a very local area,
such as in a room or in adjoining rooms, and, along with the restriction on outdoor operation, balanced the
need to provide sufficient power for U-NII devices with protection of co-channel NGSO/MSS operations.
37.
Discussion. The Commission adopted technical rules for the U-NII-1 band in 1997 that it
believed would provide sufficient flexibility for the introduction of a variety of short-range
communication devices within localized indoor settings. Although that vision was reasonable at the time,
we find that today—over 15 years since those rules were adopted—the wireless device market has
changed dramatically and the assumptions made in 1997 may not be valid for today’s market. Unlicensed
communication links are included in a wide variety of devices which are increasingly mobile or portable
in nature, not easily limited to indoor locations, and often needing more power to link with other networks
at farther locations.
38.
At the same time, we must protect incumbent authorized services, both Federal and non-
Federal. The U-NII-1 band is used for feeder links by a global NGSO/MSS network that requires co-
channel interference protection.47 We also need to consider the potential for interference to services in the

44 See supra para. 5.
45 We note that NTIA in conjunction with the Federal agencies performed an assessment of the viability of
accommodating commercial wireless broadband services in the1.755-1.85 GHz band, and that they have identified
the 5.15-5.25 GHz band as a comparable band to relocate aeronautical mobile telemetry systems. See United States
Department of Commerce, An Assessment of Viability of Accommodating Wireless Broadband in the 1755-1850
MHz Band
(March 2012).
46 See Amendment of Parts 2, 25 and 97 of the Commission's Rules with Regard to the Mobile-Satellite Service
Above 1 GHz, ET Docket No. 98-142, Report and Order, 17 FCC Rcd 2658 (2002) (FCC 02-23).
47 Globalstar Licensee LLC and GUSA Licensee LLC (collectively referred to as “Globalstar”) are wholly owned
subsidiaries of Globalstar, Inc. Globalstar’s space stations are authorized to receive uplink transmissions from the
feeder link stations in the 5096-5250 MHz band. Globalstar’s feeder link earth stations in Clifton, Texas also
transmit telecommand signals to the satellites in the 5091-5092 MHz band. See Globalstar Licensee LLC
Application for Modification of Non-geostationary Mobile Satellite Service Space Station License, Order, 26 FCC
Rcd 3948 (DA 11-520).
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bands immediately adjacent to the U-NII-1 band. Microwave landing systems operate below 5.15 GHz,
and the Commission has proposed to add an allocation for Aeronautical Mobile Telemetry at 5.091-5.15
GHz.48
39.
We seek comment on whether the rules for the U-NII-1 band should be modified to
harmonize with the rules for the U-NII-2A band in three areas.49 Specifically, we seek comment on
whether we should increase the power limits to those applicable in the U-NII-2A band, i.e., 250 mW with
a maximum EIRP of 30 dBm with 6 dBi antenna gain.50 We also invite comment on whether the rules for
the U-NII-1 band should be modified to increase the PSD limits to those applicable in the U-NII-2A band,
i.e., 11 dBm/MHz.51 Finally, we seek comment on whether the rules for the U-NII-1 band should be
modified to eliminate the restriction on outdoor operation, and, if we were to do so, whether we should
allow outdoor operation only under the current power and PSD limits for the band or under the limits now
permitted only in the U-NII-2 bands. We believe that these changes would permit a new generation of
wireless devices to be developed in the U-NII bands, particularly if industry develops wider bandwidth
devices that would operate across multiple U-NII band segments. Harmonizing the power and use
conditions across the lower 200 megahertz of U-NII spectrum would likely permit the introduction of a
wide-range of new broadband products capable of operating at higher data rates than is now possible. We
seek comment on these assumptions, and on the potential impacts to incumbent services, including any
suggestions for mitigating interference.
40.
We also seek comment on whether the rules for the U-NII-1 band should be modified to
harmonize with the rules for the U-NII-3 band to: (a) increase the power limits to 1 W with a maximum
EIRP of 36 dBm with 6 dBi antenna gain; (b) increase the PSD limits to 17 dBm; and (c) limit out-of-
band emissions to an EIRP of -27 dBm/MHz and (d) eliminate the restriction on outdoor operation. We
believe that these changes would permit for wider bandwidth devices that would not rely on contiguous
spectrum under new Wi-Fi standards, discussed below, and would permit the introduction of more
outdoor access points for broadband use. We seek comment on these assumptions, and on the potential
impacts to incumbent services, including any suggestions for mitigating interference.
41.
We invite comment on the benefits of adopting either of these approaches as well as the
costs of doing so. We ask that commenter’s assessment of adopting either approach weigh and compare
the benefits and costs to do so. This assessment should address which costs should be borne by U-NII
device manufacturers, U-NII device operators or other third parties, as appropriate.
3.

Ensuring Compliance with the Rules for the U-NII Bands

42.
Background. As stated above, in early 2009, the FAA reported interference to their
TDWR systems that operate within the 5.6-5.65 GHz band.52 The interference manifests itself as a strobe
or lines on the radar display. Through further study, investigation, and enforcement activity, we have

48 See Amendment of Parts 1, 2, 15, 74, 78, 87, 90, and 97 of the Commission’s Rules Regarding Implementation of
the Final Acts of the World Radiocommunication Conference (Geneva, 2007) (WRC-07), Other Allocation Issues,
and Related Rule Updates, ET Docket No. 12-338, Notice of Proposed Rulemaking and Order, 27 FCC Rcd 14598
(2012) (FCC 12-140).
49 The U-NII-2A band includes requirements for DFS to protect radar operations and TPC to protect EESS
operations, neither of which operates in the U-NII-1 band. Thus U-NII-1 devices would not need to include these
functions.
50 See 47 C.F.R. § 15.407(a)(2).
51 Id.
52 See also NTIA, Technical Report TR 11-473. John E. Carroll et.al., Case Study: Investigation of Interference into
5 GHz Weather Radars from Unlicensed National Information Infrastructure Devices, Part I (Technical Report Part
I), p. 1, available at http://www.its.bldrdoc.gov/publications/.
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found that the interference at each location has generally been caused by a few fixed 5 GHz wireless
transmitters operating outdoors in the vicinity of the airports at high elevations that are line-of-sight to the
TDWR installations. In most instances, the interference is caused by operations in the same frequency
band as TDWR, but there are some instances where the interference is caused by adjacent channel
emissions. Such interference is unacceptable and must be eliminated, given the public safety risks.53
43.
The Commission’s Enforcement Bureau working cooperatively with the FAA has been
successful in finding and resolving a large number of interference cases. In some cases, equipment that
met the Commission’s certification standards nonetheless caused interference, due to a variety of factors
such as the configuration of the transmitter, its height and azimuth relative to the TDWR, and the device’s
failure to detect and avoid the radar signal.54 In many cases, however, the Commission staff found that
the interfering devices were not certified or otherwise were not compliant with our rules.55 For example,
we found that devices that were certified as digital devices under Section 15.247 for operation in the
5.725-5.850 GHz band had been unlawfully modified to transmit in the U-NII-2C band without
demonstrating compliance with the DFS and TPC requirements for those bands. Typically, these
modifications are made by operators of the devices, but manufacturers have produced equipment that is
easily modified, especially through software changes, to permit devices to operate in non-compliant
modes. The Enforcement Bureau is continuing to take action against companies for operating devices
that cause interference to the TDWRs.56 We note that, while the TDWRs have been the focus of
Commission investigations, DFS was designed to protect all incumbent radar operations and modification
of devices as described above poses a risk of interference to more than just TDWRs.
44.
Interference studies conducted by NTIA and the FAA indicate that there may be some
potential for interference from U-NII devices operating in frequencies occupied by or adjacent to radar
systems. In its Third Technical Report, NTIA explores frequency separations, distance separations, and
maximum U-NII emissions limits needed to preclude harmful interference into the TDWR.57 The report
analyzes the distances at which U-NII transmissions can be expected to routinely interfere with TDWR
receivers. U-NII devices on rooftops, towers, and other high points that are 153 m to 305 m (500 to 1000
ft.) above ground level, as NTIA observed in San Juan, PR, will interfere with a TDWR mainbeam at
distances within 25 km to 41 km (16 mi to 25 mi), respectively, of a TDWR station.58 The report also
specifies frequency separations necessary to protect TDWR from interference due to unwanted emissions
from U-NII devices.
45.
As a result of its ongoing discussions with NTIA, FAA and industry representatives, as
well as the results of investigations conducted by the Commission, NTIA and FAA, and discussed above,
the Office of Engineering and Technology has provided applicants for certification a representative way
for demonstrating that their U-NII devices should not cause harmful interference to TDWR installations
operating in the U-NII-2C band and accordingly can be authorized for manufacture and use. Specifically,

53 See Memorandum from Julius Knapp, Chief, Office of Engineering and Technology, FCC, and P. Michele
Ellison, Enforcement Bureau, FCC, to Manufacturers and Operators of Unlicensed 5 GHz Outdoor Network
Equipment Re: Elimination of Interference to Terminal Doppler Weather Radar (TDWR) (dated July 27, 2010),
available at: http://www.fcc.gov/encyclopedia/weather-radar-interference-enforcement.
54 Id. See also Technical Report Part I, p. 23, available at http://www.its.bldrdoc.gov/publications/.
55 See supra para. 9.
56 See supra note 13.
57 See NTIA Technical Report TR-12-486, Case Study: Investigation of Interference into 5 GHz Weather Radars
from Unlicensed National Information Infrastructure Devices, Part III (Technical Report III), available at:
http://www.its.bldrdoc.gov/publications/2677.aspx
58 Id. at 10-13.
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OET has advised applicants that it will approve such devices upon assurance by the applicant that: (a) U-
NII devices may not operate co-frequency with TDWR operations at 5.6-5.65 GHz;59 (b) grantee will
provide owners, , operators and installers of these devices with instructions that a master or client device
within 35 km of a TDWR location must be separated by at least 30 megahertz (center-to-center) from the
TDWR operating frequency and procedures for registering the devices in an industry-sponsored
database;60 (c) the device does not include configuration controls to change the frequency of operation to
any frequency other than those specified in the grant of certification; and (d) the device’s software
configurations do not allow for ad hoc networking, country code selection, or other mode of operation
that would disable the DFS functionality of the U-NII device.61
46.
The interference cases we have seen to date raise serious concerns with ensuring
compliance with the Commission’s rules in the U-NII-2C band, but there are other circumstances that also
make this an opportune time for the Commission to consider compliance issues across the 5 GHz U-NII
bands. For example, unlicensed wireless broadband device manufactures are now designing devices
employing wider bandwidths (e.g., IEEE 802.11ac standard currently in development) using transmitters
that are capable of operating across two or more U-NII bands. When devices are designed to operate
across multiple frequency bands, the Commission’s rules require that applicants demonstrate compliance
with the rules for each of the individual frequency bands in which they intend to operate in order to be
certified for operation in each band.
47.
We expect that more and more devices with even wider bandwidths will continue to be
introduced in the 5 GHz band in the not too distant future as a result of new technical standards. The
introduction of wider bandwidths under the IEEE 802.11ac standard presents complex issues for
emissions testing to demonstrate compliance with the various requirements in the different U-NII bands.
The Office of Engineering and Technology has published two guidance documents addressing these
issues for testing of devices designed under this new standard as well as “pre-ac” devices, taking into
account the current rules that permit authorization of digitally modulated devices under both Sections
15.407 and 15.247.62
48.
Discussion. The Commission, NTIA, and the FAA have been working with
manufacturers of U-NII devices and the WISPA to fully understand the causes of interference to TDWR
systems and to identify ways to mitigate and significantly reduce the likelihood of interference. The
Commission believes the rules proposed herein, in addition to continuing enforcement efforts, will enable
us to achieve this goal while allowing U-NII devices to continue to operate successfully in the 5 GHz
band.
49.
Wireless networking devices that operate within the 5 GHz band typically have similar
operational parameters, so that a device certified for operation in any one of the 5 GHz frequency bands,
whether a U-NII band or not, can be easily tuned to another frequency band in the same spectrum range
through software modifications. Our experience with these devices shows that some of these devices are

59 This restriction is placed on the certification grant as a condition of operation.
60 We note that the Wireless Internet Service Providers Association (WISPA) maintains a (voluntary) database
accessible to the public, containing TDWR system locations. See http://www.wispa.org.
61 See FCC, OET, “Interim Plans to Approve UNII Devices Operating in the 5470-5725 MHz Band with Radar
Detection and DFS Capabilities”, KDB Publication No. 443999 DO1. See, e.g., KDB 594280 available at:
http://www.fcc.gov/labhelp.
62 See supra note 37. The Commission has already approved devices designed to the 802.11ac standard, which IEEE
has published as an interim standard. The Commission’s rules permit OET to recognize the use of measurement
procedures endorsed by industry standards groups, which often includes interim published standards, or even
suggested by equipment applicants themselves, provided they fully document the approach. See 47 C.F.R. §
2.947(a).
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designed so that end-users can modify them to operate in bands for which they are not certified and thus
do not meet the specific requirements intended to protect sensitive incumbent services. For example, in
some recent interference cases investigated by the Commission’s Enforcement Bureau, operators of
devices certified under Section 15.247 were tuned down into the U-NII-2C frequency band and operated
with a higher gain antenna than what is permitted by our U-NII rules.63 The modification of devices in
this manner resulted in both in-band and out-of-band emissions that were far in excess of what Section
15.407 allows in the U-NII-2C band. Such unlawful modification and operation of these devices could
considerably increase the distance at which these non-compliant devices cause harmful interference to
incumbent services. We believe that our proposals, discussed above, to authorize all digitally modulated
devices under identical rules in a modified Section 15.407 will allow us to more effectively and
efficiently address interference risk to incumbent operations in the U-NII-2C and U-NII-3 bands.
50.
We believe that we should consider additional steps to further reduce the likelihood of
interference not only to TDWR systems but to all other incumbent services in the 5 GHz bands as more
composite and wideband devices are introduced across the 5 GHz band. We recognize that one of the
difficulties in ensuring compliance with our current rules comes from the fact that these devices can easily
be re-configured by operators modifying the software that controls the device’s operational parameters,
such as frequency band. This makes it difficult for the Commission not only to ensure compliance with
its rules but also to enforce those rules.
51.
Because the current and future use of the 5 GHz bands is heavily reliant on the successful
implementation of our technical rules, we propose to require that manufacturers implement security
features in any digitally modulated device capable of operating in the U-NII bands, so that third parties
are not able to reprogram the devices to operate outside the parameters for which the device was certified.
We propose and seek comment on adopting this safeguard regardless of whether or how we modify
Sections 15.247 or 15.407. We are particularly concerned that U-NII devices- which are not certified
under the Commission’s rules as software defined radios (SDRs)64 and thus may lack safeguards that are
required for certified SDRs – may nevertheless be susceptible to manipulation by third parties who can
modify the operating parameters of country code, frequency range, modulation type, maximum output
power or the circumstances under which the transmitter has been approved.65 Specifically, we seek
comment on whether we should require manufacturers to make it difficult for third parties to reprogram
the embedded transmitter chip in certified devices. For example, should we require that manufacturers
ensure that modifying or reconfiguring firmware or software will make a device inoperable in certain
bands? We also seek comment on whether we should require U-NII devices to transmit identifying
information so that, in the event interference to authorized users occurs, we can identify the source of
interference and its location. What type of information should be transmitted and in what format?66

63 See, e.g., VPNet, Inc., Notice of Apparent Liability for Forfeiture and Order, 27 FCC Rcd 2879 (Enf. Bur. 2012).
64 The Commission will approve a device as an SDR, which permits authorized third parties to make certain changes
to the radio’s operating parameters consistent with the scope of the radio’s certification, provided that the grantee
has incorporated security measures to prevent unauthorized third parties from modifying the radio. See 47 C.F.R. §
2.944.
65 The Office of Engineering and Technology has published guidance on these issues which clarifies that any
installer, fabricator, or operator cannot modify a radio to operate outside the parameters for which the device is
certified. See Restrictions on Software Configuration for devices not approved as Software Defined Radios, KDB
594280, published October 24, 2012, available at www.fcc.gov/labhelp.
66 We note, for example, that our rules require unlicensed fixed TV band devices to transmit identifying information
that conforms to a standard established by a “recognizable industry standards setting organization” and should be
sufficient “to identify the device and its geographic coordinates.” See 47 C.F.R. § 15.711(d).
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52.
Although we believe that requiring manufacturers to secure the software in their radios to
prevent modifications by third parties provides a clear public benefit in ensuring that these devices
comply with our rules as more devices are introduced and the number of users increases, we recognize
that this requirement will add some cost to these devices. We seek comment on the proposals discussed
above, particularly information on the costs to manufacturers for implementing them. We invite comment
on the benefits of adopting these proposals as well as the costs to do so. We ask that commenter’s
assessment of adopting the proposals weigh and compare the benefits and costs to do so. This assessment
should address which costs should be borne by U-NII device manufacturers, U-NII device operators or
other third parties, as appropriate.
53.
We believe that our proposals to modify the technical rules in the U-NII-3 band, along
with our proposal to enhance the security requirements of all U-NII devices, would have prevented most
of the interference cases that we have observed to date. We also note, however, that the NTIA Third
Technical Report and our own discussions with NTIA, FAA and industry representatives have identified
additional techniques that could mitigate in-band and adjacent band interference to incumbents. These
include using a database registration process combined with geo-location technology to determine
whether there is any potential interference to radar systems such as the TDWR; limiting the unwanted
emission levels of the U-NII devices; or increasing the sensing frequency range (e.g., detection
bandwidth) of U-NII devices operating in the U-NII-2A and U-NII-2C bands. These other techniques,
could supplement or replace the assurances (described above in paragraph 45) that OET has accepted
from certification applicants on an ad-hoc basis as sufficient to address interference concerns that might
otherwise warrant denial of equipment certification requests for U-NII devices in the U-NII-2C band. We
also observe that these techniques would place responsibility on users, rather than on manufacturers, for
mitigating interference. We invite comment on whether the security requirements we are proposing to
place on U-NII devices, along with the more stringent unwanted emission limits that we are proposing for
devices that would previously have been certified under Section 15.247, are sufficient to protect
incumbent radar operations, including TDWR installations, from interference, or whether we should
further modify our rules to require implementation of other techniques, discussed below. In particular, we
seek comment on the likely effectiveness of each technique discussed below in reducing the incidence of
interference to TDWR systems or other incumbent operations by ensuring compliance with and in
facilitating enforcement of our rules. We invite comment on whether any of these techniques would be
beneficial in protecting other incumbents from interference, not only in the U-NII-2C band but also in
other segments of the 5 GHz band. We invite comment on the benefits of adopting any of the methods
discussed below as well as the costs to do so. We ask that commenters’ assessment of adopting any of the
methods below weigh and compare the benefits and costs to do so. This assessment should address which
costs should be borne by U-NII device manufacturers, U-NII device operators or other third parties, as
appropriate.
54.
Geo-Location/Database: The NTIA Third Technical Report specifies the frequency
separations and distance separations needed to preclude interference from U-NII devices into the TDWR
under the study conditions used for NTIA’s investigation. The separation requirements differ for the
various types of devices, but, in general, as the frequency separation increases the required separation
distance between the U-NII devices and the TDWR decreases. For example, with main-beam coupling
and ±30 megahertz of frequency separation from 20 megahertz-wide 802.11-based U-NII devices
operating at an EIRP of 17 dBm, a TDWR needs a protection distance of 11 km. For 40 megahertz-wide
802.11 devices with a frequency separation of ±30 megahertz, the distance is 35 km; that distance is
reduced to 15 km at a frequency separation of 50 megahertz above the center frequency and 10 km below
the center frequency with a 50 megahertz frequency separation.67 As noted above, the Office of

67 These frequency separations are based on the difference in center frequency of the TDWR and the center
frequency of the U-NII system. In the case of a 20 megahertz-wide U-NII device, 30 megahertz of separation
(continued....)
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Engineering and Technology has implemented these geographic and frequency separations as part of its
equipment authorization program. Industry representatives have recommended to Commission staff that
we should implement these protections for high power point-to-point systems, and have argued that no
additional limits or requirements are necessary for lower power, indoor systems.68 We seek comment on
whether we should require these geographic and frequency separations from TDWR and other Federal
radars operating in the U-NII-2C band for high power outdoor U-NII devices authorized for operation in
this band. How should we define and distinguish outdoor versus indoor U-NII devices, or high power
versus low power U-NII devices? How would we enforce compliance with these distinctions?
55.
One way to implement frequency and distance separation requirements is to require geo-
location and database registration. Because the TDWR locations are known and somewhat limited in
number, implementation of geo-location and database registration might be very straightforward and easy
to accomplish.69 With this interference avoidance method, the location of an unlicensed device could be
determined by a professional installer or by using geo-location technology such as GPS incorporated
within the device. Using either of these methods, a user could determine from either an internal or
external database whether the unlicensed device is located far enough from the TDWR to avoid causing
harmful interference; if not, it could transmit on a frequency farther away from the TDWR’s center
frequency. CSMAC, for example, recommends implementing a Dynamic Database approach to device
authorization.70 On a going-forward basis, devices and systems sharing a band would be “connected”
devices and a geo-location/database approach could enforce permission and terms-of-use updates on an
automated basis. The concept of database-enabled cognitive radios can lend itself to many applications,
including ultimately sharing spectrum with Federal users. As noted above, a voluntary database has been
implemented by WISPA, which disseminates the location of TDWR to WISPs and encourages operators
that install devices within 35 km or the line-of-sight of a TDWR, to operate at least 30 megahertz away
from the TDWR operation frequencies.71 WISPA has also agreed to voluntarily provide a database where
WISPs can register the locations of the outdoor transmitters that they use. We seek comment on whether,
given the limited number of TDWR locations, a geo-location/database approach could be effectively
implemented and maintained for numerous U-NII devices that would operate in the 5.6-5.65 GHz band.
How will this approach protect other incumbent operations?
56.
We recognize that our rules already require radar avoidance via the DFS mechanism. We
further recognize that requiring the implementation of a database for TDWR could increase the
complexity of U-NII devices if we require that they include a geo-location capability. Alternatively, we
could modify our rules to specifically require professional installation and permit manufacturers to pass
on this cost to the user of the device. In addition, a database for registering TDWR locations and,

(...continued from previous page)
between the center frequency of the TDWR and the U-NII device is equivalent to 20 megahertz of separation
between the TDWR center frequency and the band edge of the U-NII device.
68 See Letter to Dr. Rashmi Doshi, OET, FCC from Broadcom, Marvell, Intel and Qualcomm Atheros, dated Sept. 9,
2011; Letter to Dr. Rashmi Doshi, OET, FCC from Cisco Systems, dated Jan. 1, 2013. The companies suggest
criteria for identifying devices operating in the 5.57-5.68 GHz band that are primarily consumer access points that
pose little risk of interference to TDWR operations. Copies of these letters have been placed in the docket file for
this proceeding.
69 The FAA could add additional TDWR stations and/or make changes to the TDWR transmission parameters in the
future.
70 CSMAC, Unlicensed Subcommittee, Presentation of Final Report of Recommendations, July 24, 2012, at pages
5-8. The Commerce Spectrum Management Advisory Committee (CSMAC) advises the Assistant Secretary for
Communications and Information at NTIA on a broad range of spectrum policy issues.
71 See http://www.wispa.org/?q=node/84 . See also http://spectrumbridge.com/udrs/home.aspx.
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perhaps, U-NII device users and locations as well would entail some cost to establish and maintain. We
seek comment on what the cost would be to implement geo-location/database protection, what the
requirements should be, and how to define “professional installation.” We also seek comment on whether
requiring the implementation of both DFS and geo-location interference protection mechanisms would be
overly burdensome for equipment manufacturers and whether it is necessary to require both. Are there
alternative approaches that can be implemented to protect the incumbent radar systems? Because higher
power outdoor devices (such as those used by Wireless Internet Service Providers) in the U-NII-2C band
have a greater potential to cause harmful inference as compared to lower power consumer type devices,
we request comment on whether a geo-location/database requirement should apply only to those devices
or to lower power indoor U-NII devices as well.
57.
Unwanted emission limits. Emissions outside of the U-NII device’s occupied bandwidth
may have the potential to cause harmful interference into TDWR. Aside from increasing frequency
separation or distance separation, U-NII devices may avoid causing interference by lowering the
emissions on the radar’s fundamental frequency. This equates to lowering all emissions from U-NII
devices at the frequencies outside of the device’s operating bandwidth.72 We seek comment as to whether
TPC also contributes to reductions in unwanted emissions. For example, if the TPC function reduces the
fundamental power level by 1 dB, is there a corresponding 1 dB reduction in unwanted emissions?
58.
NTIA’s report details the measurements and analysis that determine the power levels at
which TDWR receivers experience interference from U-NII emissions at an interference-to-noise (I/N)
ratio of -8 dB.73 In its report, NTIA finds that the maximum allowable co-channel interference power that
can be received in the TDWR without exceeding the I/N level of -8 dB is shown to be -119 dBm/MHz at
the antenna terminals. This equates, for example, to a mainbeam-to-mainbeam interference power density
of -43 dBm/MHz between TDWR and U-NII transmitters at a distance of 8 km, or an interference power
density of -22 dBm/MHz when the mainbeam of the U-NII device is in the TDWR sidelobe at a distance
of 2 km. These power density thresholds are a function of separation distance between TDWR receivers
and U-NII transmitters as well as the receive antenna gain of the TDWR in the direction of the U-NII
transmitter.74
59.
Our existing rules for the U-NII-2C band specify that the peak power spectral density
shall not exceed 11 dBm in any 1 megahertz band. If transmitting antennas of directional gain greater
than 6dBi are used, both the maximum conducted output power and the peak power spectral density must
be reduced by the amount in dB that the directional gain of the antenna exceeds 6 dBi.75 These rules
implicitly allow a maximum EIRP of 17 dBm/MHz in the U-NII-2C band.76 Additionally, for devices
operating within the U-NII-2C band, our rules specify that all emissions transmitted outside of the U-NII-
2C band shall not exceed an EIRP of -27 dBm/ MHz.77 We recognize, based on NTIA’s report, that these

72 Commission rules typically specify unwanted emission levels outside of the frequency band in which the
unlicensed device is intended to operate, without requiring further attenuation on frequencies outside of the device’s
occupied bandwidth, but still within the specified frequency band.
73 See NTIA Technical Report III at pages ix and 15. NTIA notes that the value of -8 dB I/N is used solely for the
purpose of demonstrating interference analysis techniques. A different value, either higher or lower, could have just
as easily been used for such demonstration purposes. The FAA has not determined interference protection criteria
for this receiver.
74 See Technical Report III at pages ix-x, 19-20, available at http://www.its.bldrdoc.gov/publications/.
75 See 47 C.F.R. §15.407(a)(2).
76 Though the rules do not explicitly state a spectral density limit on EIRP, Section 15.407(a)(2) imposes an 11
dBm/MHz limit on conducted power spectral density for devices with antenna gains up to 6dBi. Thus, the effective
limit on EIRP spectral density is 17 dBm/MHz. See 47 C.F.R. § 15.407(a)(2).
77 See 47 C.F.R. §15.407(b)(3).
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two limits may not be sufficient to protect the TDWR from adjacent channel emissions from U-NII
devices. Accordingly, we seek comment on whether requiring new unwanted emission78 limits for U-NII
devices operating in the U-NII-2A and UNII-2C bands is appropriate and whether we should modify our
emission limits to reflect NTIA’s findings.
60.
If we were to impose new limits on U-NII devices, as suggested above, we believe that
different limits can be set for lower power indoor and higher power outdoor devices. For indoor devices,
we believe that setting an out-of-channel emissions limit of -27dBm/MHz maximum EIRP may be
appropriate because building materials would likely further attenuate these emissions. When measured
outside of the building, the emissions from an indoor device would likely drop to a level that would
appear as no more than -41dbm/ MHz.79 An out-of-channel emissions limit of -41 dBm/MHz for outdoor
devices may be appropriate as well. We seek comment modifying our rules to adopt these out-of-channel
limits for indoor versus outdoor U-NII devices, including how we should define the terms “indoor” and
“outdoor”, and how different operating requirements for indoor versus outdoor operations can be
accommodated through our equipment authorization and our enforcement procedures.
61.
As an alternative, if we determine that reductions in unwanted emissions are necessary,
we could allow outdoor devices to operate with an out-of-channel emissions limit of -27 dBm/MHz peak
EIRP as long as the separation distance between the device and the TDWR is at least 53 km.80 Should the
Commission impose this new out-of-channel limit based on the maximum power levels of the devices
rather than whether a device is based indoor or outdoor? For instance, we recognize that lower power
device devices provide short-range communications, such as those between computing devices within a
very local area and therefore pose less of a potential risk to TDWR operations. Higher power devices,
however, are intended to be used in an outdoor environment for longer-range communications. We seek
comment on the assumptions made in our analysis.
62.
Sensing. If we decide to require that a U-NII device move more than 30 megahertz81 in
frequency from the TDWR, one way to enable this is to require the U-NII device to sense for radar in the
channels adjacent to its occupied bandwidth. This will ensure that the unwanted emissions from U-NII
devices are placed far enough away in frequency from the TDWR fundamental frequency to preclude
harmful interference. We seek comment on this alternative approach.
63.
The DFS mechanism is designed to avoid co-channel interference to the TDWR by
dynamically detecting radar signals and avoiding co-channel operation with those systems. The efficacy
of the DFS mechanism is dependent upon the U-NII device’s ability to detect and avoid a radar pulse
within a region of its occupied bandwidth. Specifically, our current measurement procedures require that
a U-NII device sense for radar across 80 percent of its occupied bandwidth. With respect to the
remaining 20 percent, we do not require sensing in a 10 percent region above or below the occupied

78 The out-of-channel limit refers to the region of spectrum between the edge of the occupied bandwidth of the U-
NII device and the edge of the U-NII band of operation.
79 See National Institute of Standards and Technology, NISTIR 6055, William C. Stone, NIST Construction
Automation Program, Report No. 3, Electromagnetic Signal Attenuation in Construction Materials, available at
http://fire.nist.gov/bfrlpubs/build97/PDF/b97123.pdf.
80 See NTIA Technical Report III , page 15, Equation - 6. -27dBm/MHz used for EIRPmax and solved for
the separation distance, available at http://www.its.bldrdoc.gov/publications/.
81 Requiring 30 megahertz separation between the U-NII device and the TDWR frequencies is specific to a U-NII
device employing a 20 megahertz bandwidth. For devices with wider bandwidths, the frequency separation will
have to be greater than 30 megahertz means 20 megahertz separation from the edge of the emission bandwidth to the
fundamental frequency of the TDWR.
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bandwidth.82 We recognize that currently implementation of the sensing bandwidth will ensure co-
channel interference protection only when the radar signal falls within 80 percent of the U-NII device’s
occupied bandwidth. Therefore, it is possible for the U-NII device to transmit on the same frequency as
the radar when the radar signal falls within the 20 percent of occupied bandwidth that does not require
sensing. When the radar signal falls within the region of occupied bandwidth that does not require
sensing, the U-NII device will continue to transmit. This could result in simultaneous and overlapping
transmissions from the U-NII device and the TDWR, which would increase the potential for harmful
interference.
64.
In addition, NTIA’s Third Technical Report suggests that adjacent channel interference is
possible when the frequency separation between the radar and the U-NII device is less than a specified
amount. For example, when a radar signal falls outside of the sensing bandwidth and occupied
bandwidth, and is within 30 megahertz from the U-NII devices’ fundamental frequency, the unwanted
emissions from the U-NII devices could still cause harmful interference to the TDWR. If we require that
U-NII devices sense for radar on the frequencies immediately adjacent to the occupied bandwidth, we
would ensure that the fundamental frequency is more than 30 megahertz away from the radar.
65.
We seek comment on whether we should implement a rule requiring that U-NII devices
sense for radar signals at or exceeding 100 percent of its occupied bandwidth, or whether we should
continue to reference this, as we do now, as part of the U-NII measurement procedures. We believe that
expanding the sensing bandwidth will prevent the co-channel operations between U-NII devices and
radars receiver and thus will reduce the potential for harmful interference. We also invite comment on the
technical difficulty and cost of implementing this capability in U-NII devices.
4.

The U-NII-2A and U-NII-2C Bands

66.
Background. The DFS mechanism is designed to avoid co-channel interference to
incumbent Federal radar systems by dynamically detecting radar signals and avoiding co-channel
operation with those systems. Our rules require that U-NII devices use two detection thresholds to
ascertain whether radar signals are present, and we have issued measurement guidelines and procedures
for testing the DFS functionality as part of our equipment certification program. We have found that even
devices certified to operate in the U-NII band have the potential to cause harmful interference to the
TDWR and potentially other radar systems in the U-NII-2A and U-NII-2C. For instance, NTIA has found
that certain manufacturers provided an option for users to deactivate the DFS mechanism. Furthermore,
evidence from our Enforcement Bureau also suggests that the deactivation of DFS in certain devices
caused harmful interference to the TDWR. In addition, certain parameters of the DFS mechanism may
need improvement to enhance protection to vital incumbent systems within the U-NII-2A and U-NII-2C
bands.
67.
Discussion. DFS is an essential element allowing U-NII devices to share the U-NII-2A
and U-NII-2C bands successfully with vital government and military radar systems. As we have gained
experience with these devices and the implementation of DFS in the field, we are proposing changes in
three areas to improve the utility and reliability of this function, thus ensuring that incumbent services in
these bands are protected from interference. These changes include lowering the permitted PSD for lower
power devices that use the relaxed sensing threshold, and modifying the Bin-1 radar simulating waveform
used in our measurement procedures. We believe that these changes will reduce the potential for co-
channel interference to the TDWR and other radar systems. We are also proposing to remove the uniform
channel loading requirement found in our measurement procedures.

82 See Compliance Measurement Procedures for Unlicensed National Information Infrastructure Devices Operating
in the 5250-5350- MHz and 5470-5725 MHz Bands Incorporating Dynamic Frequency Selection (DFS Compliance
Measurement Procedures
) at: http://transition.fcc.gov/oet/ea/eameasurements.html.
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68.
DFS Functionality. To be certified for operation in the U-NII-2A and U-NII-2C bands,
devices must include a DFS radar detection function. In its field investigations, the Commission’s
Enforcement Bureau found that certain models of devices certified for use in these bands were designed
so that users could disable the DFS mechanism by setting the device’s operating mode to “Compliance
test.” In other cases, the device’s DFS mechanism could be turned off by manually changing the
“Country Code” for the device. If the DFS mechanism is not active, the device could transmit on an
active radar channel and cause harmful interference. We therefore propose that manufacturers prevent
the DFS mechanism from being disabled in devices certified to operate in the U-NII-2A and U-NII-2C
bands. We also propose that U-NII devices certified to operate in these bands must be operated with the
DFS function on.
69.
Recently, the Office of Engineering and Technology has had to clarify which types of U-
NII devices are required to demonstrate compliance with the DFS requirement.83 We know that many U-
NII devices operate in a master-client configuration, i.e., the master device controls the operational
parameters of the client devices.84 Typically, DFS-enabled master devices would include both the radar
sensing and DFS functions, but new configurations are being designed. For example, radios can operate
in a network configuration with the sensing function distributed among various “client” devices. Also,
some radios are designed so that they can communicate directly with each other, rather than through a
control point, and thus they could function as either a “master” that initiates a network or as a “client”
device within the network. We propose that any U-NII device that is subject to the DFS requirements in
Section 15.407 that is capable of initiating a network must have radar detection functionality and must be
approved with that capability.
70.
We believe that responsible operation of U-NII devices in these bands is a joint
responsibility of both manufacturers and users. We seek comment on these proposals regarding DFS
functionality as well as information on costs to implement them. We also invite comment on whether the
DFS requirement has limited in any way the types of applications that have been or could be implemented
in the U-NII-2A and U-NII-2C bands, particularly if wider bandwidth devices are deployed in this
spectrum. We invite comment on the benefits of adopting this proposal as well as the costs to do so. We
ask that commenters’ assessments of adopting the proposal weigh and compare the benefits and costs to
doing so. This assessment should address which costs should be borne by U-NII device manufacturers,
U-NII device operators or other third parties, as appropriate.
71.
Sensing Threshold for Co-channel operation: The current rules require that the DFS
mechanism continuously monitor the device’s environment for the presence of radar, both prior to and
during operation. We further require that U-NII devices certified under our rules use two detection
thresholds to ascertain whether radar signals were present. The required threshold levels are: (a) -62 dBm
for lower power devices with a maximum EIRP less than 200 mW (23 dBm), and (b) -64 dBm for higher
power devices with a maximum EIRP between 200 mW (23 dBm) and 1 W (30 dBm), averaged over 1
s.85 We also require that the conducted peak power spectral density shall not exceed 11 dBm in any 1
megahertz band. If transmitting antennas of directional gain greater than 6 dBi are used, we require that
both the maximum conducted output power and the power spectral density be reduced by the amount in

83 See supra note 65.
84 The Commission’s rules define a client device as “a device operating in a mode in which the transmissions of the
device are under control of the master. A device in client mode is not able to initiate a network.” See 47 C.F.R. §
15.202.
85 See 47 CFR §15.407(h)(2). The DFS detection threshold is defined as the received power averaged over 1 s
referenced to a 0 dBi antenna.
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dB that the directional gain of the antenna exceeds 6 dBi. Thus, the implicit limit on the EIRP spectral
density is 17 dBm in any 1 megahertz band.86
72.
The lower power U-NII devices are permitted to use the relaxed sensing threshold
because the range at which these devices can potentially cause interference is reduced and thus they are
allowed to operate closer to the radar. In order to ensure that interference potential does not increase with
the use of the relaxed sensing threshold, we believe that applying a reduction in EIRP spectral density for
devices that use the -62 dBm sensing threshold is appropriate. We propose that devices must operate with
both an EIRP of less than 200 mW (23 dBm), and an EIRP spectral density of less than 10 dBm/MHz (10
mW/MHz), in order to use the relaxed sensing detection threshold of -62 dBm. Devices that do not meet
the proposed EIRP and EIRP spectral density requirements must use the -64 dBm sensing threshold. The
proposed changes will further enhance protection for radars from co-channel interference by reducing
both the range and the in-band spectral density emissions of the U-NII device. We seek comment on this
proposal, including the cost to manufacturers to implement it. We note that a reduction in the EIRP
spectral density limit would be consistent with recent actions taken by European Telecommunications
Standards Institute (ETSI).87 Specifically, ETSI chose to restrict a device’s use of the relaxed sensing
threshold by reducing both the EIRP and the EIRP spectral density by 7 dB to 23 dBm (200 mW) and 10
dBm/MHz (10 mW/MHz), respectively. We invite comment on the benefits of adopting this proposal as
well as the costs to do so. We ask that commenter’s assessment of adopting the proposal weigh and
compare the benefits and costs to do so. This assessment should address which costs should be borne by
U-NII device manufacturers, U-NII device operators or other third parties, as appropriate.
73.
Measurement and Testing Procedures. Under Section 2.947(a) of the rules, the
Commission will accept data that is measured in accordance with (1) procedures or standards set forth in
bulletins or reports prepared by the Commission’s Office of Engineering and Technology (OET), (2)
procedures or standards that are acceptable to the Commission and are published by a national
engineering society, or (3) any other measurement procedure acceptable to the Commission.88 With
respect to the first option, OET’s most recent bulletin on measurement procedures for U-NII devices with
DFS capabilities was published in 2006.89 NTIA has recommended modifications to these 2006
measurement procedures, to further enhance protection for the TDWR.90 We invite interested parties to
comment on these modifications to the measurement procedures, which are set forth in Appendix B, and
to propose any additional modifications that are appropriate. Consistent with our rules and prior practice,

86 See 47 CFR §15.407(a)(2). The EIRP power spectral density is the amount of power per unit of spectrum.
87 ETSI EN 301 393 V1.6.1, Broadband Radio Access Networks; 5 GHz high performance RLAN; Harmonized EN
covering the essential requirements of article 3.2 of the R&TTE Directive (2011-11), Page 70. The proposed limits
are those that were adopted by ETSI. This new ETSI standard did not exist when our previous rules were written.
Adopting a rule that is consistent with ETSI standards will allow us to continue to harmonize with worldwide
standard that will, in turn, foster American industry’s flexibility to develop devices for international markets and
promote economies of scale in production of equipment.
88 47 C.F.R. § 2.947(a)(1)-(3).
89 See U-NII Reconsideration Order, 21 FCC Rcd at 7681 (Appendix A).
90 See Letter from Lawrence E. Strickling, Administrator, NTIA to Julius Genachowski, Chairman, FCC, filed
February 19, 2013, and the enclosure Appendix - Proposal for New Unlicensed National Information Infrastructure
Dynamic Frequency Selection Certification Waveforms
. A copy of this document has been placed in the docket file
for this proceeding.
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the Office of Engineering and Technology will evaluate comments on the recommended changes to the
measurement procedures and will issue updated measurement procedures in the future as needed.91
74.
Our current rules and measurement procedures require that the DFS function provide a
uniform spreading of loading over all available channels.92 The measurement procedure further explains
this provision by stating that “Uniform Channel Spreading” is the spreading of U-NII devices operating
over the DFS bands to avoid dense clusters of devices operating on the same channel. Some
manufacturers comply with this requirement by using random channel selection, but we believe that
similar benefits could be obtained by manual selection of channels and may actually result in better
spectrum usage at a given location. In particular, we note that enhanced spectrum use may be possible
when devices use a very high bandwidth and the number of usable channels is small. We also note that
the trend for U-NII devices is to operate with ever wider bandwidths. Operation over wider bandwidths
causes U-NII energy to be spread throughout the frequency band in which the device is operating, rather
than concentrated in a narrow bandwidth. This potentially makes the uniform channel spreading
requirement unnecessary. We propose to remove the “Uniform Channel Spreading” requirement from
our rules and measurement procedures. We also propose to permit either random channel selection or
manual selection of the initial channel. For example, should we permit a device to create a master list of
available channels that it would use if they continue to be available? We seek comment on whether these
changes will, in any way, negatively impact spectrum reuse or potentially increase interference to
incumbent users. In addition, our measurement procedures require that system testing be performed with
an MPEG test file that streams full motion video at 30 frames per second for channel loading. Experience
certifying U-NII devices has indicated that not all U-NII devices are designed for video transmission or
support the specific coding format, and so other methods of channel loading are used. We seek comment
on whether specifying video streaming as the preferred channel loading method for compliance
measurements is as appropriate today as it was when the measurement procedures were created, or
whether the channel loading requirement in our test procedures should be specified in a more general
manner so as only to specify that measurements be conducted with the device under test operating in a
loaded condition. We seek comments on how we should specify alternate means of channel loading for
measurement purposes. Additionally, we seek comment on the effects of wider U-NII device bandwidths
on channel loading requirements.

B.

Future Unlicensed Operations at 5 GHz

75.
The 5.35 – 5.47 GHz (U-NII-2B) and 5.85 – 5.925 GHz (U-NII-4) bands have great
potential for fostering ongoing technological innovation, expanding broadband access, and encouraging
competitive entry. The additional spectrum also would expand opportunities for innovative spectrum
access models by creating new avenues for opportunistic and unlicensed use of spectrum and increasing
research into new spectrum technologies. Creating ways to access spectrum under a variety of new
models, including unlicensed uses, increases opportunity for entrepreneurs and other new market entrants
to develop wireless innovations that may not have otherwise been possible under licensed spectrum
models.
76.
These bands currently are used for various Federal and non-Federal services, and the
Spectrum Act requires that the Commission begin a proceeding to modify the Part 15 rules to permit
unlicensed devices in the U-NII-2B band93 if, in consultation with NTIA, it determines that licensed users
will be protected by technical solutions and that the primary mission of Federal spectrum users will not be

91 See 47 C.F.R. § 2.947(a). We note that, although these revisions to the 2006 measurement procedures are not
substantive rule changes that require notice and comment under the Administrative Procedures Act, this proceeding
provides a convenient vehicle to assist OET in crafting reliable and efficient measurement procedures.
92 See 47 C.F.R. §15.407(h)(2).
93 Spectrum Act, § 6406(a)(1).
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compromised by the introduction of unlicensed devices in these bands.94 Thus, our goal in this
proceeding is to promote efficient use of radio spectrum through spectrum sharing. As part of this
collaborative effort and as required by the Spectrum Act, NTIA has published a report, prepared in
consultation with Department of Defense and other impacted Federal agencies, evaluating spectrum-
sharing technologies and the risk to Federal users of unlicensed operations in the U-NII-2B and U-NII-4
bands.95
77.
In the discussion below, we explore the potential for future unlicensed operations in the 5
GHz band, incumbent operations in the U-NII-2B and U-NII-4 bands, and the technical requirements and
sharing technologies and techniques that could be used to protect Federal and non-Federal incumbent
operations. We also invite comments on the NTIA 5 GHz Report itself, including its underlying
assumptions and risk assessments.
1.

Future Unlicensed Operations at 5 GHz

78.
The current U-NII bands are already being used for a variety of different commercial uses
such as wireless internet services, cordless phone, scientific and medical applications, etc. In this
proceeding, we seek comment on what types of uses could be deployed in the U-NII-2B and U-NII-4
bands, used either independently of the current U-NII bands or in conjunction with them. We are
interested in knowing how companies of different types might deploy U-NII devices, what types of
services they might offer, and where they might deploy them. We are particularly interested in gathering
information on ongoing industry standards activity and international efforts to harmonize uses of the 5
GHz band to make more efficient use of the 5 GHz spectrum.
79.
We know, for example, that unlicensed and licensed broadband networks often
complement one another in important ways. The availability of unlicensed Wi-Fi networks in many
locations enables licensed wireless providers to take data traffic off of their networks, thus reducing
network congestion and delivering a better overall quality of service.96 Wi-Fi technology also can be
“networked” to provide wider geographic coverage and, when configured this way, may be used by some
service providers in offering broadband service.
80.
The introduction of the IEEE 802.11ac standard, discussed above, can open new
windows to wireless broadband for many users. The deployment of wide channel bandwidths with higher
data rates in the 5 GHz band can help meet the challenge that rapid growth in demand has posed for the
wireless industry which has called for more spectrum to increase network capacity. The new standard has
the potential to create new avenues for opportunistic use of spectrum in diverse broadband services.
Some forecasts predict that in 2015, shipments of mobile phones with embedded Wi-Fi are projected to
approach 800 million and by the same time 100 percent of mobile hotspot shipments will be 802.11ac
enabled.97 Infonetics forecasts the global carrier Wi-Fi equipment market to grow significantly at least
through 2016, when it will hit $2.1 billion.98 We seek comment on how the introduction of this new
standard might be implemented in the U-NII bands and how these developments should inform our
consideration of technical requirements for these bands and sharing technologies and techniques, which
are discussed in more detail below. We also invite comment on whether some technologies or techniques,

94 Id. at §6406(a)(2).
95 See NTIA 5 GHz Report.
96 See supra note 17. National Broadband Plan at 95.
97 Zero to a Billion; 802.11ac-Enabled Device Shipments to Soar by 2015, In-Stat (February 08, 2011), available at
http://www.marketwire.com/press-release/zero-to-a-billion-80211ac-enabled-device-shipments-to-soar-by-2015-
says-in-stat-1391854.htm.
98 Carrier Wi-Fi equipment market exploding to $2.1 billion by 2016, Infonetics research (May 10, 2012), available
at
: http://www.infonetics.com/pr/2012/Carrier-WiFi-Equipment-Market-Highlights.asp.
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such as DFS, might limit the types of applications that could be implemented in the U-NII bands,
particularly if wider bandwidth devices are deployed in this spectrum.
81.
Also, at the 2012 World Radio Conference, the United States along with other countries
agreed that the next World Radio Conference in 2015 (WRC-15) should consider additional spectrum
allocations to the mobile service for the development of terrestrial mobile broadband applications. In
preparation for WRC-15, the International Telecommunications Union initiated spectrum sharing studies
that consider possible expansion of the existing international allocations to the mobile services in the 5
GHz band which are used primarily by the radio local area network (RLAN) devices.99 We seek
comment on how these activities should inform our consideration of technical requirements for these
bands and sharing technologies and techniques, which are discussed in more detail below. We also seek
comment on importance and benefits of harmonization between our U-NII rules and the international
radio regulations.
2.

Incumbent Services in the U-NII-2B Band

82.
The 5.35 – 5.47 GHz band is allocated on a primary basis to the Earth Exploration
Satellite, Space Research, and Radiolocation Services for Federal operations and on a secondary basis for
non-Federal operations.100 The 5.35-5.46 GHz band segment is allocated on a primary basis to the
Aeronautical Radionavigation Service for both Federal and non-Federal operations.101 The 5.46-5.47
GHz band segment is allocated on a primary basis to the Radionavigation Service for both Federal and
non-Federal operations.102 The Table below summarizes these incumbent service allocations.

Frequency Band

Service Type

Federal

Non-Federal

Non-Federal

Primary

Primary

Secondary

5.35 -5.47 GHz
Earth Exploration Satellite
X
X
5.35 -5.47 GHz
Space Research
X
X
5.35 -5.47 GHz
Radiolocation
X
X
5.35 -5.46 GHz
Aeronautical Radionavigation
X
X
5.46 -5.47 GHz
Radionavigation
X
X
a.

Overview of Federal Systems

83.
RADAR Systems. The DoD uses the 5.35-5.47 GHz band for a wide variety of ground-
based, shipborne, and airborne radars. These military radars have the operational capability to tune across
the entire 5.25-5.725 GHz frequency range and can operate on a fixed frequency or can employ frequency
hopping techniques. In the past, these radars have operated on or near military installations. However,
situations may arise where these radars have to be used more widely in support of homeland security.
One of the areas of concern in assessing interference to military radars stems from future radar
deployments and the expanding role of military radars in support of homeland defense. This expanded
role could result in a requirement to deploy military radars in cities and metropolitan areas where

99 The pre-conference studies are being conducted by the ITU-R Joint Task Group (JTG) 4-5-6-7. Refer to ITU-R
Document 4-5-6-7/109, 16 November 2012.
100 See 47 C.F.R. § 2.106.
101 Id.
102 Id.
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unlicensed devices will have their highest usage.103 In addition to DoD, several other agencies operate
radar systems in the band. The Coast Guard operates shipborne radars, which are vital sensors for safe
navigation of waterways. NASA uses this band for test and launch range instrumentation radars to track
rockets, missiles, satellites, launch vehicles, and other targets. NOAA operates radar systems in this band
on “Hurricane Hunter” aircraft. The Department of Energy operates radar systems and associated
transponders in the band at two test ranges in the United States.
84.
Spaceborne Altimeter Radar Systems. NASA, in joint ventures with the French agency,
Centre National d'Etudes Spatiales (CNES), operates a space-based altimeter system in the 5.14-5.46 GHz
band that is used to obtain measurements of the Earth’s ocean surface height.
85.
Earth Exploration Satellite. Synthetic aperture radar (SAR) systems in the 5.35-5.47 GHz
band perform space-based observations and measurements of surface topography, soil moisture, and sea
surface height. The higher quality data collected using wideband SARs allow scientists to gain new
insights into the prediction of climatic changes. These wideband SARs also provide the higher resolution
necessary for commercial applications, such as high-resolution surface mapping. Canada operates an
Earth exploration-satellite, known as RADARSAT, in the 5.35-5.47 GHz band to provide mission critical
data in support of national security, public safety, law enforcement, and civilian applications in Canada
and the United States. These applications include disaster management, response and recovery for safety
of life, ice monitoring, surveillance, hydrology, mapping, and geology, safety of navigation, agriculture,
and forestry. For example, the United States Coast Guard International Ice Patrol uses RADARSAT data
operationally to detect and track icebergs.
86.
Unmanned aircraft systems (UAS).104 DoD utilizes this band for the testing and operation
of unmanned aircraft system (UAS) datalinks from aircraft-to-ground and from ground-to-aircraft. The
command link, a ground data terminal transmitter, operates at 5.625-5.85 GHz and the return link (UAS
transmitter) transmits at 5.25-5.475 GHz. The Army, Navy, and Air Force operate UASs in the 5 GHz
frequency range for intelligence, surveillance, and reconnaissance; combat search and rescue; and real-
time full-motion video for target development. The Department of Homeland Security also operates
UASs in this band for drug interdiction and border surveillance operations.105 In addition, NASA also
operates a limited number of systems in the 5.35-5.47 GHz band that are used for downlink transmissions
of data to ground control receivers.
b.

Overview of Non-Federal Systems

87.
The types of Federal and non-Federal systems in the 5.35-5.47 GHz band are similar
except that non-Federal users in the Earth Exploration Satellite, Space Research, and Radiolocation
Services operate on a secondary basis. Broadcast and media entities use radars operating in the 5.35-5.47
GHz band for tracking storms and providing weather radar information to the public via news and
weather reporting. Weather radars are employed by broadcasters throughout the USA and used to detect
supercell storms capable of developing tornados and severe weather. Local TV stations throughout the
country utilize 5.35-5.47 GHz band providing viewers with weather maps, weather pictures, and
informing the public on a range of local and regional weather warnings. Part 90 of FCC rules permit the
operation of weather radar services in the 5.35-5.47 GHz band.

103 NTIA 5 GHz Report at 4-1 to 4-2.
104 There is no allocation for UAS operations in the 5.35-5.47 GHz band; however, NTIA has authorized Federal
agencies to operate UAS systems throughout the United States on a non-interference basis.
105 NTIA 5 GHz Report at 4-2.
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3.

Incumbent Services in the U-NII-4 Band

88.
The 5.85 – 5.925 GHz band is allocated on a primary basis to the Radiolocation Service
for Federal operations and to the Fixed Satellite (Earth to space) and Mobile Services for non-Federal
operations.106 This band is also allocated on a secondary basis to the Amateur Service for non-Federal
operations. The Table below summarizes these incumbent service allocations.

Frequency Band Service Type

Federal

Non-Federal

Non-Federal

Primary

Primary

Secondary

5.85-5.925 GHz
Radiolocation
X
5.85-5.925 GHz
Fixed Satellite(Earth to Space)
X
5.85-5.925 GHz
Mobile Service
X
5.85-5.925 GHz
Amateur Service
X
a.

Overview of Federal Systems

89.
The radars that operate in the 5.825-5.925 GHz band are primarily military surveillance
and test range instrumentation systems and can be either mobile or transportable. In addition to the DoD
operation, NASA, NOAA, and Department of Energy operate radar systems in the 5.85-5.925 GHz band
throughout the United States.107
b.

Overview of Non-Federal Systems

90.
Fixed Satellite Services (FSS). The C-band is divided into a heavily-used “conventional”
segment (3.7-4.2 GHz downlink and 5.925-6.425 GHz uplink) and a lightly-used “extended” segment
(3.6-3.7 GHz downlink and 5.85-5.925 GHz and 6.425-7.075 GHz uplink). The non-Federal fixed-
satellite service allocation in the extended C-band FSS (5.85-5.925 GHz) is limited to international inter-
continental systems and is subject to case-by-case electromagnetic compatibility analysis.108 Earth
stations in stationary locations communicate uplink with geostationary satellites such as Intelsat,
Inmarsat, JCSAT-2, Mabuhay, New Skies, and Galaxy. The earth stations and satellites use directional
antennas which, along with the separation between the satellites, prevent interference with earth stations
communicating with adjacent satellites. The FSS operations in the 5.85-5.925 GHz band are authorized
under Part 25 of the FCC rules.
91.
The FSS is widely used to provide a variety of commercial services domestically and
internationally. For example, the FSS supports video distribution both on point-to-point basis and point-
to-multipoint bases. The FSS also provides network services consisting of “backbone” capacity for point-
to-point trunking for voice, data or Internet traffic; backhaul of communications services; and redundancy
and restoration of communications services when other primary technologies fail. Further, the FSS is
used to provide corporate, government, and military voice and data communications, as well as
broadband and video services directly to the home.
92.
Intelligent Transportation Service (ITS). The non-Federal Mobile allocation is limited to
Dedicated Short Range Communications Service (DSRC) systems operating in the Intelligent

106 See 47 C.F.R. § 2.106.
107 NTIA 5 GHz Report at 5-2 to 5-3.
108 See 47 C.F.R. § 2.106 Table of Allocations, footnote US245. The FCC policy for this band is codified at
47C.F.R. § 2.108.
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Transportation System radio service.109 ITS is a national program aimed at using state-of-the-art
communications system to make travel more efficient, safer and convenient for motorists, transit riders,
commercial vehicle operators and public safety providers. Through the use of technologies such as
roadside and/or overhead Variable Message Signs, Closed Circuit TV, Highway Advisory Radio
transmitters, traffic counter loops and Transcom's System for Managing Incidents and traffic flow
monitors, real-time traffic information is collected and conveyed to the traveling public. This multi-
modal information then allows motorists to make smarter choices about how, when and where to travel.
93.
DSRC is a wireless ITS system designed for automotive use. In October 1999, the FCC
allocated 75 megahertz of spectrum in the 5.85-5.925GHz band for DSRC to be used by ITS.110 DSRC is
a two-way short- to- medium-range wireless communications capability that permits very high data
transmission critical in communications-based active safety applications.111 DSRC which involves
vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications can save lives by warning
drivers of an impending dangerous condition or event in time to take corrective or evasive actions.112
Vehicle safety applications that use V2V and V2I communications need secure, wireless interface
dependability in extreme weather conditions, and short time delays; all of which are facilitated by
DSRC.113 FCC grants licenses for state and regional transportation agencies to operate DSRC roadside
units, while DSRC onboard units are licensed by rule under Part 95.114
94.
Amateur Radio. Amateur service stations are permitted to transmit in the 5.85-5.925
GHz frequency segment on a secondary basis. Operation of these stations in this frequency segment must
not cause harmful interference to, and must accept interference from, authorized stations in the fixed-
satellite (earth to space) and mobile services (DSRC) and also stations authorized by other nations in the
fixed service.115 The FCC does not have detailed information on use of this band by amateur service
stations.
4.

Technical Requirements for U-NII-2B and U-NII-4 Bands

95.
The technical requirements for U-NII devices operating in the U-NII-2B and U-NII-4
bands will depend ultimately on a determination of the types of unlicensed operations that can be
supported while maintaining interference protection to incumbent Federal and non-Federal users.
Nonetheless, we believe that because the types of incumbent services across the 5 GHz spectrum share

109 See 47 C.F.R. § 2.106 Table of Frequency Allocations- Non-Federal Government footnote NG-160.
110 See Amendment of Parts 2 and 90 of the Commission’s Rules to Allocate the 5.850-5925 GHz Band to the
Mobile Service for Dedicated Short Range Communications of Intelligent Transportation Services, ET Docket No.
98-95, Report and Order, 14 FCC Rcd 18221 (1999)(FCC 99-305).
111 U.S. Department of Transportation Research and Innovative Technology Administration, DSRC: The Future of
Safer Driving Fact Sheet, http://www.its.dot.gov/factsheets/dsrc_factsheet.htm (last visited Jan. 16, 2013).
112 See Amendment of the Commission’s Rules Regarding Dedicated Short-Range Communication Services in the
5.850-5.925 GHz Band (5.9 GHz Band); Amendment of Parts 2 and 90 of the Commission’s Rules to Allocate the
5.850-5.925 GHz Band to Mobile Service for Dedicated Short Range Communications of Intelligent Transportation
Services; WT Docket No. 01-90, ET Docket No. 98-95, Report and Order, 19 FCC Rcd 2458 (2004)(FCC 03-324).
113 See supra note 111.
114 The DSRC Road Side Units (RSUs) are authorized under Part 90 (Subpart M) of the Federal Communications
Commission (FCC) rules. The On-Board Units (OBUs) are authorized under Part 95 (Subpart L) of the FCC rules.
In addition, Section 90.371of the Commission’s rules indicates that DSRCS Roadside Units (RSUs) in the 5.85-
5.925 GHz require NTIA coordination if operating within 75 kilometers of 59 DoD radar installations.
115 See 47 C.F.R. § 97.303(r)(2).
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similar characteristics, the technical requirements for unlicensed devices also could share similar
characteristics.
96.
U-NII-2B Band. The U-NII-2B band falls between the existing U-NII-2A and U-NII-2C
bands. Most significantly, all three bands are allocated for Federal Earth Exploration Satellite, Space
Research and Radiolcoation Services on a primary basis, and sensitive services such as Federal radar
systems operate across all three bands. This suggests that U-NII devices could likely operate under the
same technical framework specified in rule Section 15.407 in all three bands ranging from 5.25 – 5.725
GHz.116 Thus, U-NII devices could operate across 475 megahertz either indoors or outdoors under the
following power and emission limits: maximum output power limit is the lesser of 250 milliwatts and
11dBm+10 Log (B), where B is 26 dB emission bandwidth; antenna gain requirement is 6 dBi for non-
point to-point systems and 23 dBi for point-to-point system; and power and power spectral density
reduction is applied if the antenna gain exceeds these values. The maximum power spectral density
should not exceed 11 dBm in any 1 megahertz band, and the out-of-band emission limit shall not exceed
an EIRP limit of -27 dBm/MHz.117 The out-of-channel emissions limit for an outdoors device should not
exceed -41 dBm/MHz. We invite comment on these technical parameters for U-NII-2B devices.
97.
U-NII-4 Band. The U-NII-4 band is situated 25 megahertz above the U-NII-3 band. A
primary Federal allocation for Radiolocation Services and a non-Federal secondary allocation for
Amateur Services range across the U-NII-3 and U-NII-4 bands, including the 25 megahertz located
between them at 5.825-5.85 GHz. This suggests that U-NII devices should operate under the same
framework and technical requirements specified in Section 15.407 in all three bands ranging from 5.725 –
5.925 GHz. We propose that the U-NII-3 rules be applied to the upper adjacent 25 megahertz band
segment at 5.825-5.85 GHz. If we adopt this proposal, we believe that the same framework and technical
requirements specified in Section 15.407 should apply across the expanded U-NII-3 and the U-NII-4
bands. Thus, U-NII devices could operate across 200 megahertz either indoors or outdoors under the
following power and emission limits: maximum output power limit is the lesser of 1Watt and 17dBm+10
Log (B) where B is 26 dB emission bandwidth; antenna gain requirements is 6 dBi for non-point to-point
systems and 23 dBi for point-to-point systems; and power and power spectral density reduction is applied
if the antenna gain exceeds these values. The maximum power spectral density should not exceed 17
dBm in any 1 megahertz band, and out-of-band emissions within the frequency range from the band edge
to 10 megahertz above or below the band edge should not exceed an EIRP limit of -17 dBm/MHz, and for
frequencies 10 megahertz or greater, the emissions should not exceed an EIRP of -27 dBm/MHz.118 We
invite comment on these technical parameters for U-NII-4 devices.
98.
Spectrum Sensing/DFS and TPC. The rules require that U-NII devices operating in the
U-NII-2A and U-NII-2C bands employ Dynamic Frequency Selection (DFS) in order to avoid causing
interference to Federal radar systems. We seek comment whether and how to integrate a DFS algorithm
into U-NII-2B and U-NII-4 bands. What are the advantages and/or disadvantages of utilizing DFS in
these bands? What are the technical challenges of DFS technology implementation in the U-NII-2B and
U-NII-4 bands? What changes are necessary in the existing DFS model to mitigate possible interference
with incumbent radar system in the new bands? What radar parameters/signal detection threshold should
be used for DFS to avoid assigning the occupied radar channel to U-NII device? If the U-NII device
would have to perform sensing outside its occupied bandwidth (adjacent channel sensing), what would be
the technical and cost implications of such deployment? Should the radar signal detection be sensed by
base/fix stations, mobile stations or all? Are there technical solutions other than DFS that would prevent

116 See 47 C.F.R. § 15.407 (a)(2)-(3).
117 See 47 C.F.R. § 15.407(b)(2)
118 See 47 C.F.R. § 15.407(b)(4)
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interference to Federal radar systems? Could database access offer any benefits for providing access to
this spectrum while protecting incumbent services against harmful interference?
99.
The signal detection technology currently used by U-NII-2A and U-NII-2C DFS devices
senses radar signals whose parameters (such as pulsewidth, pulse repetition interval, and the number of
pulses per burst) are well-known and can be used to improve signal detection. To improve range
resolution and accuracy, some radar systems operating in the U-NII-2B and U-NII-4 bands employ short
(sub-microsecond) pulse widths.119 The smallest pulsewidth used in the development of the existing U-
NII DFS regulations was 1 microsecond. A narrower radar pulsewidth used in conjunction with the
higher data rates associated with the 802.11ac standard could affect a device’s ability to detect pulsed
radar signals.120 We seek comment on the ability of signal sensing spectrum-sharing technologies to
detect sub-microsecond pulses and whether the current DFS mechanism would protect the current and
future radars that employ sub-microsecond pulses. Are there other detection mechanisms that could be
considered?
100.
In addition, some fielded and in-development radar systems in the U-NII-2B and U-NII-4
bands include low-power modes or are designed to avoid detection to meet their mission requirements.121
We seek comment on whether DFS or any other spectrum-sharing technology would be capable of
protecting such radar systems from possible interference.
101.
Finally, what measures should be taken to protect non-radar systems that operate in the
U-NII-2B and U-NII-4 bands and what is the cost implication for manufacturers, vendors and consumers?
We seek comment on what types of sharing technology or techniques could be used to protect non-radar
systems, such as the DSRCS which includes both road side units (RSU-fixed) and on board units (OBU-
mobile) operating under a primary allocation. For example, U-NII signal detection technologies used for
DFS may not be able to detect signals from incumbents other than radar systems. Could U-NII devices
detect signals from both DSRC fixed and mobile stations? We seek comments on evolving
technologies that may help to detect non-radar signals and to protect those operations from harmful
interference.
5.

NTIA 5 GHz Report

102.
NTIA has published a report of its initial study on the potential for U-NII devices to share
the U-NII-2B and U-NII-4 bands with incumbent Federal operations.122 The report includes an initial
evaluation of known and proposed spectrum-sharing technologies and also completed a high-level
evaluation of the risk to Federal users if the Commission allows U-NII devices to operate in the U-NII-2B
and U-NII-4 bands.123
103.
NTIA, in collaboration with the Federal agency members of the Policy and Plans Steering
Group (PPSG), developed a work plan for evaluating the risks to Federal systems operating in the U-NII-
2B and U-NII-4 bands. The plan outlined the technical and operational information necessary to perform
the evaluation. Several Federal agencies also conducted preliminary electromagnetic compatibility and

119 NTIA 5 GHz Report at 5-8. A narrow pulsewidth also improves radar detection capabilities in cluttered
environments.
120 Id.
121 Id.
122 We note that the NTIA 5 GHz Report does not use the same numerical designation for the 5 GHz band segments
that we use in this proceeding. The report refers to both the U-NII-2A and U-NII-2C bands as “UNII-2.” The report
does use the same numerical designations as this proceeding for the U-NII-1 and U-NII-3 bands, but it does not
assign numerical designations for the two new bands that we have designated as U-NII-2B and U-NII-4.
123 NTIA 5 GHz Report at 1-1.
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interference analyses to begin to quantify risks to their systems.124 NTIA also used input from industry
stakeholders related to their projected technical and deployment parameters for U-NII devices,125 and
reviewed domestic and international technical studies used in the development of the existing U-NII
regulations in performing their study. For the study, NTIA assumed that the FCC’s existing U-NII TPC
and DFS regulations would be extended to the U-NII-2B and U-NII-4 bands, and that the Federal
agencies will not have to alter their systems or operations to accommodate U-NII devices.126 The report
concludes that additional analysis is needed to determine the feasibility of introducing U-NII devices into
these two bands and includes a tentative schedule and milestones for quantitative study consistent with
the ongoing work for WRC-15, discussed above.
104.
We seek comments on all aspects of the NTIA 5 GHz Report, particularly the spectrum
sharing technologies and risk analysis described below.
a.

Spectrum Sensing Technologies

105.
The report addresses three spectrum sharing technologies that might be used as reference
models in the U-NII-2B and U-NII-4 bands. These are classified as sensing based, geo-location based,
and beaconing/pilot channel technologies.
106.
Sensing based technology. Sensing based spectrum sharing approaches enable radio
devices to identify unused spectrum by assessing and determining current use of a particular frequency
through, for example, transmitter detection, cooperative sensing, or interference detection. Transmitter
detection is the capability of determining if a signal from another transmitter is using a frequency nearby
by correlating a known signal with an unknown signal (matched filter detection), measuring signal energy
(signal detection), or utilizing statistical means. Cooperative sensing incorporates information about the
spectral environment from multiple sensing devices to accurately determine if spectrum is in use.
Interference detection refers to sensing changes in the local noise floor to determine if additional traffic
can be tolerated by primary users.127
107.
Geo-Location based technology. This approach requires the development of a database
infrastructure that contains information about incumbent spectrum users which, when used in
combination with a geo-location system (e.g., the Global Positioning System (GPS)) and an interference-
free location-data communications link, provides a mechanism to facilitate spectrum sharing with
incumbents operating at fixed or known locations with known technical parameters.128 Geo-location
spectrum-sharing technologies can be used in conjunction with a well maintained updated database to
define geographic areas where device operation will and will not be permitted, or where limitations
should be placed on the operating parameters to enable spectrum sharing.129
108.
Beaconing/pilot channel technology. In a beacon spectrum sharing approach, a new
entrant’s transceiver must have the ability to receive a control signal sent continuously by incumbent
systems at times when transmissions by the new entrant are permitted. The new entrant may not

124 Id.
125 NTIA 5 GHz Report at 1-3 (citing Letter from Mary L. Brown, Director, Government Affairs, Cisco Systems,
Inc. to Karl Nebbia, Associate Administrator, Office of Spectrum Management, NTIA (Sept. 26, 2012) (Industry
Input
).
126 NTIA 5 GHz Report at 1-2.
127 NTIA 5 GHz Report at 2-4 to 2-5. The report discusses about each sensing technologies and presents the
advantages and disadvantages of each sensing approach.
128 See supra note 70. See also NTIA 5 GHz Report on at 2-6.
129 Id.
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commence transmissions if beacon signals are not received. If any beacon signal is present but then stops
while the new entrant is transmitting, transmissions must cease within a specified time interval. The
beacons could be a radio frequency signal sent by incumbents on designated control frequencies, or they
may be signals received over a physical connection such as fiber, copper, or coaxial cable. Transmission
by the new entrant would cease if any beacon signal suffers from unfavorable propagation conditions or
the physical connection is lost such that the beacon signals are not properly received by the new entrant.
In other words, if the new entrant cannot hear the beacon signal, it must cease transmission.130
b.

Risk Analysis

109.
The NTIA 5 GHz Report provides an overview of the risk elements to each type of
Federal operation and suggests some mitigation strategies associated with each risk element for further
investigation.
110.
Description of risk elements in U-NII-2B band. The report indicates that changes in radar
signal parameters may impact U-NII device detection of radar and changes in U-NII device deployment
and technical parameters may result in harmful interference into radar systems. The report also
emphasizes that the current U-NII regulations may introduce hidden node interference131 and may not
adequately protect current and future radar systems while changes in the existing U-NII DFS detection
parameters, including channel response time, may not sufficiently shield current and future radar systems
from serious degradation. The report extends the risk element to the U-NII devices operating on an
adjacent channel and states this may cause harmful interference into radar systems. The report also
specifies that the radar receiver interference protection criteria used to develop existing U-NII DFS
regulations may not address low-level interference effects.132
111.
The report states that the existing U-NII signal detection technologies may not be capable
of detecting UAS signals because the existing U-NII regulations were not developed to detect such
signals (there is no UAS signal in the bands governed by the existing U-NII regulations) and changes to
U-NII DFS detection parameters may not protect UAS operations from performance degradation. The
report also points out that existing U-NII regulations were not developed to protect spaceborne
receivers.133 The report also states that the density of U-NII devices is one of the key parameters in
determining the amount of potential interference to the incumbent Federal systems.
112.
Description of risk elements in U-NII-4 band. The report cites the same risks to radar
systems operating in the U-NII-4 band as it cites for the U-NII-2B band discussed above.134 The report
also states that the existing U-NII signal detection technologies may not be capable of detecting DSRC
signals because the existing U-NII regulations were not originally developed to detect such signals (there
is no DSRC signal in the bands governed by the existing U-NII regulations) and changes to U-NII DFS
detection parameters may not protect DSRC operations from performance degradation.

130 NTIA 5 GHz Report at 2-7.
131 Hidden node refers to a scenario where the propagation path between the radar system and the U-NII master
device is obstructed but the propagation path between radar system and U-NII client device is unobstructed. Since
the master device cannot detect the radar signal, it may assign an occupied radar channel to the client device, which
could result in excessive interference into the radar system.
132 NTIA 5 GHz Report at 4-4 to 4-5.
133 Id.
134 NTIA 5 GHz Report at 5-4 to 5-5.
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C.

Other Issues

1.

Miscellaneous Rule Modifications

113.
In addition to the proposals outlined above, we believe that there are a number of other
changes that need to be considered to simplify and clarify Part 15 of the rules. Our analysis revealed
several sections that reference procedures or provisions that are no longer in use and therefore, may no
longer be necessary. We have also identified sections that need to be updated with minor revisions. The
proposed changes are listed below, and text of the proposed rules is provided in Appendix A. We request
comment on each of these proposals.

Section 15.403 Definitions.

We are proposing to clarify this section by replace the wording in
paragraph (m) from “Peak Power Spectral Density” with “Maximum Power Spectral Density.” In
addition, we are proposing to delete “peak or” from paragraph (o) for clarity.
● Section 15.407 General technical requirements. We are proposing to delete the second sentence in
paragraph (a)(4) because it contains language that is no longer relevant. We also propose to correct the
wording in paragraph (a)(5) by replacing “peak” with “maximum”. In addition, we are updating the
language in paragraph (a)(6) to clarify that all peak excursion measurements are to the highest average
rather than to the average in each corresponding 1 megahertz band
● Section 15.215 Additional provisions to the general radiated emission limitations. This section
includes language regarding the 20 dB bandwidth being contained entirely within a specific band as
specified in our rules. This 20 dB language was included in the UWB proceeding to preclude UWB
devices from operating at the same power levels as narrowband and wideband devices. We consider
Section 15.407 devices to be wideband devices. The 20 dB bandwidth limitation was not intended to
limit the simultaneous operation of a composite U-NII device over multiple channels. U-NII Band
straddling in the 5GHz-6GHz region of spectrum is allowed (This applies to 802.11ac bonded 80
megahertz and 160 megahertz channels). We propose to update this section to clarify that this rule does
not apply to 15.407 devices.

Section 15.247 Operation within the bands 902-928 MHz, 2400-2483.5 MHz, 5725-5850 MHz.

We
propose to correct the references in paragraph propose (b)(4)(iii) by replacing “(b)(3)(i) and (b)(3)(ii)”
with “(b)(4)(i) and (b)(4)(ii)”.
2.

Transition Periods

114.
We propose to establish a 12-month timetable after the effective date of any new or
modified rules that we eventually decide to adopt in this proceeding for manufacturers to produce U-NII
devices that comply with new or modified rules. We also propose to establish a 2-year timetable after the
effective date of any new or modified rules for requiring that any U-NII devices manufactured in or
imported into the United States for sale comply with the new or modified rules. We believe that a 12-
month transition period should provide sufficient time for manufacturers to design equipment that
complies with any new or modified rules and to obtain equipment certification. Therefore, we would
provide transitional provisions in our rules to allow for the certification of U-NII devices under the
current rules for up to 12 months after the new or modified rules are published in the Federal Register.
Beginning 12 months after the effective date of the new or modified rules, equipment certification could
no longer be obtained for U-NII devices that do not meet the new requirements. However, until the end
of the 2-year transition period, we would permit Class II permissive changes for equipment certified prior
to the 12-month transition date135 as well as their continued manufacture, marketing, installation, and

135 See 47 C.F.R. § 2.1043(b)(2).
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importation. After the end of the 2-year transition period, Class II permissive changes for such devices
would not be permitted nor would their manufacture, marketing, installation, or importation. We find that
these requirements would facilitate the transition to new requirements without unduly impairing the
availability or cost of U-NII devices or imposing undue burdens on manufacturers, translation services
providers, or the public. Comments are requested on these proposed transition provisions.
115.
We also propose that U-NII devices that are already installed or in use should be
grandfathered for the life of the equipment. Requiring the immediate upgrade or replacement of existing
U-NII devices would be a financial burden on operators of these devices. We believe that grandfathering
equipment that is installed and operating will ensure that entities will be permitted to operate their
existing U-NII devices until replacement is necessary or desired due to age, malfunction, or other
concerns. We seek comments on this proposal.

IV.

PROCEDURAL MATTERS

A.

Ex Parte Rules – Permit-But-Disclose

116.
The proceeding this Notice initiates shall be treated as a “permit-but-disclose”
proceeding in accordance with the Commission’s ex parte rules.136 Persons making ex parte presentations
must file a copy of any written presentation or a memorandum summarizing any oral presentation within
two business days after the presentation (unless a different deadline applicable to the Sunshine period
applies). Persons making oral ex parte presentations are reminded that memoranda summarizing the
presentation must (1) list all persons attending or otherwise participating in the meeting at which the ex
parte
presentation was made, and (2) summarize all data presented and arguments made during the
presentation. If the presentation consisted in whole or in part of the presentation of data or arguments
already reflected in the presenter’s written comments, memoranda or other filings in the proceeding, the
presenter may provide citations to such data or arguments in his or her prior comments, memoranda, or
other filings (specifying the relevant page and/or paragraph numbers where such data or arguments can be
found) in lieu of summarizing them in the memorandum. Documents shown or given to Commission
staff during ex parte meetings are deemed to be written ex parte presentations and must be filed
consistent with rule 1.1206(b). In proceedings governed by rule 1.49(f) or for which the Commission has
made available a method of electronic filing, written ex parte presentations and memoranda summarizing
oral ex parte presentations, and all attachments thereto, must be filed through the electronic comment
filing system available for that proceeding, and must be filed in their native format (e.g., .doc, .xml, .ppt,
searchable .pdf). Participants in this proceeding should familiarize themselves with the Commission’s ex
parte
rules.

B.

Comment Period and Procedures

117.
Pursuant to sections 1.415 and 1.419 of the Commission’s rules, 47 CFR §§ 1.415,
1.419, interested parties may file comments and reply comments on or before the dates indicated on the
first page of this document. Comments may be filed using the Commission’s Electronic Comment Filing
System (ECFS). See Electronic Filing of Documents in Rulemaking Proceedings, 63 FR 24121 (1998).

Electronic Filers: Comments may be filed electronically using the Internet by accessing the
ECFS: http://fjallfoss.fcc.gov/ecfs2/.

Paper Filers: Parties who choose to file by paper must file an original and one copy of each
filing. If more than one docket or rulemaking number appears in the caption of this proceeding,
filers must submit two additional copies for each additional docket or rulemaking number.

136 47 C.F.R. §§ 1.1200 et seq.
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Filings can be sent by hand or messenger delivery, by commercial overnight courier, or by first-
class or overnight U.S. Postal Service mail. All filings must be addressed to the Commission’s
Secretary, Office of the Secretary, Federal Communications Commission.

All hand-delivered or messenger-delivered paper filings for the Commission’s Secretary
must be delivered to FCC Headquarters at 445 12th St., SW, Room TW-A325,
Washington, DC 20554. The filing hours are 8:00 a.m. to 7:00 p.m. All hand deliveries
must be held together with rubber bands or fasteners. Any envelopes and boxes must be
disposed of before entering the building.

Commercial overnight mail (other than U.S. Postal Service Express Mail and Priority
Mail) must be sent to 9300 East Hampton Drive, Capitol Heights, MD 20743.

U.S. Postal Service first-class, Express, and Priority mail must be addressed to 445 12th
Street, SW, Washington DC 20554.
118.
People with Disabilities: To request materials in accessible formats for people with
disabilities (braille, large print, electronic files, audio format), send an e-mail to fcc504@fcc.gov or call
the Consumer & Governmental Affairs Bureau at 202-418-0530 (voice), 202-418-0432 (tty).

C.

Initial Regulatory Flexibility Analysis

119.
As required by the Regulatory Flexibility Act of 1980 (RFA), 137 the Commission has
prepared an Initial Regulatory Flexibility Analysis (IRFA) of the possible significant economic impact on
small entities of the policies and rules proposed in the Notice. The IRFA is found in Appendix D. We
request written public comment on the analysis. Comments must be filed in accordance with the same
deadlines as comments filed in response to the Notice, and must have a separate and distinct heading
designating them as responses to the IRFA. The Commission’s Consumer and Governmental Affairs
Bureau, Reference Information Center, will send a copy of this Notice, including the IRFA, to the Chief
Counsel for Advocacy of the Small Business Administration.

D.

Paperwork Reduction Analysis

120.
This document does not contain a proposed information collection(s) subject to the
Paperwork Reduction Act of 1995 (PRA, Public Law 104-13. In addition, therefore, it does not contain
any new or modified information collection burden for small business concerns with fewer than 25
employees, pursuant to the Small Business Paperwork Relief Act of 2002, Public Law 107-198, see 44
U.S.C. 3506(c)(4).

E.

Further Information

121.
For further information regarding this Notice of Proposed Rulemaking, please contact
Aole Wilkins, Technical Rules Branch, Policy and Rules Division, Office of Engineering and
Technology, Federal Communications Commission, 445 12th Street, S.W., Washington, DC 20554, at
202-418-2406 or via the Internet at Aole.Wilkins@fcc.gov.

V.

ORDERING CLAUSES

122.
IT IS ORDERED that pursuant to Sections 1, 4(i), 7(a), 301, 303(f), 303(g), 303(r), and
307(e) of the Communications Act of 1934, as amended, 47 U.S.C. Sections 151, 154(i), 157(a), 301,
303(f), 303(g), 303(r), and 307(e), and Section 6406(a) of the Middle Class Tax Relief and Job Creation

137 See 5 U.S.C. § 603.
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Act of 2012, Pub. L. No. 112-96, §6406(a), 126 Stat. 156, 231 (2012), this Notice of Proposed Rule
Making IS ADOPTED.
123.
IT IS FURTHER ORDERED that the Commission’s Consumer and Governmental
Affairs Bureau, Reference Information Center, SHALL SEND a copy of this Notice of Proposed Rule
Making, including the Initial Regulatory Flexibility Analysis, to the Chief Counsel for Advocacy of the
Small Business Administration.
FEDERAL COMMUNICATIONS COMMISSION
Marlene H. Dortch
Secretary
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APPENDIX A

Proposed Rules

PART 15 – RADIO FREQUENCY DEVICES

1. The authority citation for Part 15 continues to read as follows:

Authority:

47 U.S.C. 154, 302a, 303, 304, 307, 336, 544a, and 549
2. Section 15.215 is amended by revising paragraph (c) to read as follows:
§ 15.215 Additional provisions to the general radiated emission limitations.
*****
(c) Intentional radiators operating under the alternative provisions to the general emission limits,
as contained in §§ 15.217 through 15.257 and in Subpart E of this part, must be designed to ensure that
the 20 dB bandwidth of the emission, or whatever bandwidth may otherwise be specified in the specific
rule section under which the equipment operates, is contained within the frequency band designated in the
rule section under which the equipment is operated. In the case of intentional radiators operating under
the provisions of Subpart E, the emission bandwidth may span across multiple frequency bands identified
in that Subpart. The requirement to contain the designated bandwidth of the emission within the specified
frequency band includes the effects from frequency sweeping, frequency hopping and other modulation
techniques that may be employed as well as the frequency stability of the transmitter over expected
variations in temperature and supply voltage. If a frequency stability is not specified in the regulations, it
is recommended that the fundamental emission be kept within at least the central 80% of the permitted
band in order to minimize the possibility of out-of-band operation.
3. Section 15.247 is amended by revising paragraphs (a)(2), (b)(3) and (4) and by revising paragraph
(c)(1)(ii) and (iii) and paragraph (f) to read as follows:
§ 15.247 Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.
*****
(a) ***
(2) Systems using digital modulation techniques may operate in the 902-928 MHz, and 2400-
2483.5 MHz bands. The minimum 6 dB bandwidth shall be at least 500 kHz.
*****
(b) ***
(3) For systems using digital modulation in the 902-928 MHz, and 2400-2483.5 MHz bands: 1
Watt. As an alternative to a peak power measurement, compliance with the one Watt limit can be based
on a measurement of the maximum conducted output power. Maximum Conducted Output Power is
defined as the total transmit power delivered to all antennas and antenna elements averaged across all
symbols in the signaling alphabet when the transmitter is operating at its maximum power control level.
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Power must be summed across all antennas and antenna elements. The average must not include any time
intervals during which the transmitter is off or is transmitting at a reduced power level. If multiple modes
of operation are possible (e.g., alternative modulation methods), the maximum conducted output power is
the highest total transmit power occurring in any mode.
(4) The conducted output power limit specified in paragraph (b) of this section is based on the use
of antennas with directional gains that do not exceed 6 dBi. Except as shown in paragraph (c) of this
section, if transmitting antennas of directional gain greater than 6 dBi are used, the conducted output
power from the intentional radiator shall be reduced below the stated values in paragraphs (b)(1), (b)(2),
and (b)(3) of this section, as appropriate, by the amount in dB that the directional gain of the antenna
exceeds 6 dBi.
*****
(c) ***
(1) ***
(ii) Frequency hopping systems operating in the 5725-5850 MHz band that are used
exclusively for fixed, point-to-point operations may employ transmitting antennas with
directional gain greater than 6 dBi without any corresponding reduction in transmitter conducted
output power.
(iii) Fixed, point-to-point operation, as used in paragraph (c)(1)(i) and (c)(1)(ii) of this
section, excludes the use of point-to-multipoint systems, omnidirectional applications, and
multiple co-located intentional radiators transmitting the same information. The operator of the
spread spectrum or digitally modulated intentional radiator or, if the equipment is professionally
installed, the installer is responsible for ensuring that the system is used exclusively for fixed,
point-to-point operations. The instruction manual furnished with the intentional radiator shall
contain language in the installation instructions informing the operator and the installer of this
responsibility.
*****
(f) For the purposes of this section, hybrid systems are those that employ a combination of both
frequency hopping and digital modulation techniques. The frequency hopping operation of the hybrid
system, with the direct sequence or digital modulation operation turned off, shall have an average time of
occupancy on any frequency not to exceed 0.4 seconds within a time period in seconds equal to the
number of hopping frequencies employed multiplied by 0.4. The power spectral density conducted from
the intentional radiator to the antenna due to the digital modulation operation of the hybrid system, with
the frequency hopping operation turned off, shall not be greater than 8 dBm in any 3 kHz band during any
time interval of continuous transmission.
*****
4. Section 15.403 is amended by revising the definition in paragraph (m) to read as follows:
§ 15.403 Definitions.
*****

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(m) Maximum Power Spectral Density. The maximum power spectral density is the maximum
powerin the specified measurement bandwidth, within the U-NII device operating band.
*****
5. Section 15.407 is amended by revising paragraphs (a) (3), (4), (5) and (6) and paragraph (b)(4) and
by adding new paragraphs (f) and (j) and by redesignating paragraphs (f) through (h) as paragraphs (g)
through (i) to read as follows:
§ 15.407 General technical requirements.
*****
(3) For the band 5.725-5.850 GHz, the maximum conducted output power over the frequency band
of operation shall not exceed 1 W. In addition, the maximum power spectral density shall not exceed 8
dBm in any 3-kHz band. If transmitting antennas of directional gain greater than 6 dBi are used, both the
maximum conducted output power and the maximum power spectral density shall be reduced by the
amount in dB that the directional gain of the antenna exceeds 6 dBi. However, fixed point-to-point U-NII
devices operating in this band may employ transmitting antennas with directional gain up to 23 dBi
without any corresponding reduction in the transmitter peak output power or maximum power spectral
density. For fixed, point-to-point U-NII transmitters that employ a directional antenna gain greater than
23 dBi, a 1 dB reduction in peak transmitter power and maximum power spectral density for each 1 dB of
antenna gain in excess of 23 dBi would be required. Fixed, point-to-point operations exclude the use of
point-to-multipoint systems, omnidirectional applications, and multiple collocated transmitters
transmitting the same information. The operator of the U-NII device, or if the equipment is professionally
installed, the installer, is responsible for ensuring that systems employing high gain directional antennas
are used exclusively for fixed, point-to-point operations.
NOTE TO PARAGRAPH ( a )(3): The Commission strongly recommends that parties employing U-NII
devices to provide critical communications services should determine if there are any nearby Government
radar systems that could affect their operation.
(4) The maximum conducted output power must be measured over any interval of continuous
transmission using instrumentation calibrated in terms of an rms-equivalent voltage.
(5) The maximum power spectral density is measured as a conducted emission by direct connection
of a calibrated test instrument to the equipment under test. If the device cannot be connected directly,
alternative techniques acceptable to the Commission may be used. Measurements are made over a
bandwidth of 1 MHz or the 26 dB emission bandwidth of the device, whichever is less. A resolution
bandwidth less than the measurement bandwidth can be used, provided that the measured power is
integrated to show total power over the measurement bandwidth. If the resolution bandwidth is
approximately equal to the measurement bandwidth, and much less than the emission bandwidth of the
equipment under test, the measured results shall be corrected to account for any difference between the
resolution bandwidth of the test instrument and its actual noise bandwidth.
(6) The ratio of the maximum peak excursion of the modulation envelope (measured in a 1 MHz
bandwidth using a peak hold function) to the maximum power spectral density during an interval of
continuous transmission (measured in a 1 MHz bandwidth) shall not exceed 13 dB. Each of the two
maxima shall be separately determined across the full emission bandwidth. If the emission bandwidth is
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less than 1 MHz, the measurement may be performed in a resolution bandwidth narrower than 1 MHz but
wider than or equal to the emission bandwidth.
*****
(b) ***
(4) For transmitters operating in the 5.725-5.850 GHz band: all emissions within the frequency
range from the band edge to 10 MHz above or below the band edge shall not exceed an e.i.r.p. of -17
dBm/MHz; for frequencies 10 MHz or greater above or below the band edge, emissions shall not exceed
an e.i.r.p. of -27 dBm/MHz.
*****
(f) Within the 5.725-5.85 GHz band, the minimum 6 dB bandwidth of U-NII devices shall be
at least 500 kHz.
(g) U-NII devices are subject to the radio frequency radiation exposure requirements specified in
§ 1.1307(b), § 2.1091 and § 2.1093 of this chapter, as appropriate. All equipment shall be considered to
operate in a “general population/uncontrolled” environment. Applications for equipment authorization of
devices operating under this section must contain a statement confirming compliance with these
requirements for both fundamental emissions and unwanted emissions. Technical information showing
the basis for this statement must be submitted to the Commission upon request.
(h) Manufacturers of U-NII devices are responsible for ensuring frequency stability such that an
emission is maintained within the band of operation under all conditions of normal operation as specified
in the user’s manual.
(i) Transmit Power Control (TPC) and Dynamic Frequency Selection (DFS).
*****
(j) All U-NII Devices must contain security features to protect against modification of software by
unauthorized parties.
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APPENDIX B

Changes to Compliance Measurement Procedures For Unlicensed-National

Information Infrastructure Devices Operating in The 5250-5350 MHz and

5470-5725 MHz Bands Incorporating Dynamic Frequency Selection
In 2006, the FCC released measurement procedures to be used in certifying U-NII equipment that requires
implementation of Dynamic Frequency Selection (DFS). Based on investigations into complaints of
interference to Terminal Doppler Weather Radar (TDWR), NTIA has recommended changes to the
measurement procedures that are described within this Appendix. The original 2006 measurement
procedures have been placed into the docket of this proceeding, and are proposed to be modified as
described in this appendix.
Throughout the measurement procedures, the old waveform 1 would be renamed waveform 0. A new
waveform 1is then added to Section 6 of the measurement procedures as described below. In addition,
channel availability check and non-occupancy tests that originally specified use of waveform 1 are
proposed to now allow use of any of the waveform types 0 - 4.
In table 4 of the measurement procedure, the U-NII Detection Bandwidth is specified as a minimum of
80% of the 99% transmission power bandwidth. This sensing bandwidth is one of the technical issues on
which we are seeking comment in the NPRM, and thus we will modify the measurement procedures to
reflect the determination made in the proceeding with respect to the U-NII Detection Bandwidth.
Finally, Section 6.1 (Short Pulse Radar Test Waveforms) of the measurement procedures is proposed to
be modified to read as shown below:
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6.1

Pulse Radar Test Waveforms

Table 5 – Short Pulse Radar Test Waveforms

Radar
Pulse
PRI
Number of Pulses
Minimum
Minimum
Type
Width
(µsec)
Percentage of
Number
(µsec)
Successful
of
Detection
Trials
0
1
1428
18
See Note 1
See Note
1
1
1
Test A: 15 unique



60%
30
1
PRI values




360



randomly selected


Roundup 

from the list of 23
6
 1910 


PRI values in



 PRI





Table 5a
sec

Test B: 15 unique
PRI values
randomly selected
within the range
of 518-3066 μsec,
with a minimum
increment of 1
μsec, excluding
PRI values
selected in Test A
2
1-5
150-230
23-29
60%
30
3
6-10
200-500
16-18
60%
30
4
11-20
200-500
12-16
60%
30
Aggregate (Radar Types 1-4)
80%
120

Note 1:

Short Pulse Radar Type 0 shall only be used for the channel availability and detection
bandwidth tests. It should be noted that any of the radar test waveforms 0 – 4 can be used for
the channel availability and detection bandwidth tests.
A minimum of 30 unique waveforms are required for each of the Short Pulse Radar Types 2 through 4. If
more than 30 waveforms are used for Short Pulse Radar Types 2 through 4, then each additional
waveform must also be unique and not repeated from the previous waveforms. If more than 30
waveforms are used for Short Pulse Radar Type 1, then each additional waveform is generated with Test
B and must also be unique and not repeated from the previous waveforms in Tests A or B.
For example if in Short Pulse Radar Type 1 Test B a PRI of 3066 usec is selected, the number of pulses
6

 1  1910 
would be Roundup 


 
 = Roundup{17.2} = 18.

 360


3066


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Table 5a - Pulse Repetition Intervals Values for Test A

Pulse Repetition

Pulse Repetition Frequency

Pulse Repetition

Frequency

(Pulses Per Second)

Interval

Number

(Microseconds)
1
1930.5
518
2
1858.7
538
3
1792.1
558
4
1730.1
578
5
1672.2
598
6
1618.1
618
7
1567.4
638
8
1519.8
658
9
1474.9
678
10
1432.7
698
11
1392.8
718
12
1355
738
13
1319.3
758
14
1285.3
778
15
1253.1
798
16
1222.5
818
17
1193.3
838
18
1165.6
858
19
1139
878
20
1113.6
898
21
1089.3
918
22
1066.1
938
23
326.2
3066
The aggregate is the average of the percentage of successful detections of Short Pulse Radar Types 1-4.
For example, the following table indicates how to compute the aggregate of percentage of successful
detections.
Radar Type
Number of Trials
Number of Successful Minimum Percentage
Detections
of Successful
Detection
1
35
29
82.9%
2
30
18
60%
3
30
27
90%
4
50
44
88%
Aggregate (82.9% + 60% + 90% + 88%)/4 = 80.2%
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APPENDIX C

EXISTING TECHNICAL SUMMARY CHARTS FOR UNLICENSED BANDS

Current technical characteristics of UNII devices for Rule Section 15.407

UNII-1

UNII-2A

UNII-2C

UNII-3

(5.150 – 5.250 GHz)
(5.250 – 5.350 GHz)
(5.470 – 5.725 GHz)
(5.725 – 5.825 GHz)

Indoor-Outdoor operations

Indoor Only
Indoor-Outdoor
Indoor-Outdoor
Indoor-Outdoor

Max TX Power, Lesser of

50 mW or
250 mW or
250 mW or
1W or
two(B= 26 dB emission BW)
4 dBm + 10 log B
11 dBm + 10 Log B
11 dBm + 10 Log B
17 dBm + 10 log B

Max EIRP (with 6 dBi Ant.)

23 dBm / 200 mW
30 dBm / 1 W
30 dBm / 1 W
36 dBm / 4 W (53 dBm / 200 W
for PTP)

Power reduction required

> 6 dBi
> 6 dBi
> 6 dBi
> 6 dBi (>23 dBi for PTP)
when antenna gain exceeds
Out of band emission

-27 dBm/MHz EIRP
-27 dBm/MHz EIRP
-27 dBm/MHz EIRP
-17 dBm/MHz EIRP for up to
10 MHz outside the band edge
and -27 dBm/MHz for further
than 10 MHz

Power Spectral Density/MHz

4 dBm
11 dBm
11 dBm
17 dBm

Dynamic Frequency

No
Yes
Yes
No

Selection (DFS) required

Transmit Power Control

No
Yes (Not required if
Yes (Not required if No
(TPC) required
EIRP<500 mW)
EIRP<500 mW)
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Current technical characteristics of devices in UNII-3 band (under Rule Section15.407) and devices under Rule Section 15.247

UNII-3 ( Rule Section 15.407)

Rule Section 15.247

(5.725 – 5.825 GHz)
(5.725 – 5.850 GHz)

Indoor-Outdoor operations

Indoor-Outdoor
Indoor-Outdoor

Max TX Power

1W or 17 dBm + 10 log B - Lesser of two
1 W
(B= 26 dB emission BW)

Max EIRP (with 6 dBi Ant.)

36 dBm / 4 W (53 dBm/200 W for PTP)
36 dBm / 4 W (No Maximum for PTP)

Power reduction required

> 6 dBi (>23 dBi for PTP)
> 6 dBi (No limit for PTP)
when antenna gain exceeds
Out of band emission

-17 dBm/MHz EIRP for up to 10 MHz outside the For any 100 KHz outside band, power should be
band edge and -27 dBm/MHz for further than 10
20 dB below that in any 100 KHz within the band.
MHz

Power Spectral Density/ MHz

17 dBm
8dBm/3KHz of TX power(33dBm/MHz)

Dynamic Frequency Selection

No
No
(DFS) required

Transmit Power Control

No
No
(TPC) required

Minimum BW Requirement

N/A
Minimum 500 KHz for 6dB BW
47

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APPENDIX D

Initial Regulatory Flexibility Analysis

1. As required by the Regulatory Flexibility Act of 1980, as amended (RFA),1 the Commission
has prepared this present Initial Regulatory Flexibility Analysis (IRFA) of the possible significant
economic impact on small entities by the policies and rules proposed in this Notice of Proposed Rule
Making (NPRM). Written public comments are requested on this IRFA. Comments must be identified as
responses to the IRFA and must be filed by the deadlines specified in the NPRM for comments. The
Commission will send a copy of this NPRM, including this IRFA, to the Chief Counsel for Advocacy of
the Small Business Administration (SBA).2 In addition, the NPRM and IRFA (or summaries thereof) will
be published in the Federal Register.3

A.

Need for, and Objectives of, the Proposed Rules

This NPRM proposes to amend Part 15 of the FCC’s rules governing the operation of unlicensed
National Information Infrastructure (U-NII) devices in the 5 GHz band. U-NII devices are unlicensed
intentional radiators that operate in the frequency bands 5150-5350 MHz and 5470-5825 MHz that use
wideband digital modulation techniques to provide a wide array of high data rate mobile and fixed
communications for individuals, businesses, and institutions. The NPRM proposes to modify certain
technical requirements for U-NII devices to ensure that these devices can continue to operate successfully
while protecting incumbent spectrum users..

B.

Legal Basis

2. This action is authorized under Sections 1, 4(i), 302, 303(f) and (r), 332, and 337 of the
Communications Act of 1934, as amended, 47 U.S.C. §§ 1, 4(i), 154(i), 302, 303(f) and (r), 332, 337.

C.

Description and Estimate of the Number of Small Entities to Which the Proposed
Rule Will Apply

3. The RFA directs agencies to provide a description of, and, where feasible, an estimate of, the
number of small entities that may be affected by the rules adopted herein.4 The RFA generally defines
the term “small entity” as having the same meaning as the terms “small business,” “small organization,”
and “small governmental jurisdiction.”5 In addition, the term “small business” has the same meaning as
the term “small business concern” under the Small Business Act.6 A “small business concern” is one
which: (1) is independently owned and operated; (2) is not dominant in its field of operation; and (3)

1 See 5 U.S.C. § 603. The RFA, see 5 U.S.C. § 601-612, has been amended by the Small Business Regulatory
Enforcement Fairness Act of 1996, (SBREFA) Pub. L. No. 104-121, Title II, 110 Stat. 857 (1996).
2 See 5 U.S.C. § 603(a).
3 See 5 U.S.C. § 603(a).
4 5 U.S.C. § 604(a)(3).
5 5 U.S.C. § 601(6).
6 5 U.S.C. § 601(3) (incorporating by reference the definition of “small-business concern” in the Small Business
Act, 15 U.S.C. § 632). Pursuant to 5 U.S.C. § 601(3), the statutory definition of a small business applies “unless an
agency, after consultation with the Office of Advocacy of the Small Business Administration and after opportunity
for public comment, establishes one or more definitions of such term which are appropriate to the activities of the
agency and publishes such definition(s) in the Federal Register.”
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satisfies any additional criteria established by the Small Business Administration (SBA).7

Radio and Television Broadcasting and Wireless Communications Equipment Manufacturing.


The Census Bureau defines this category as follows: “This industry comprises establishments primarily
engaged in manufacturing radio and television broadcast and wireless communications equipment.
Examples of products made by these establishments are: transmitting and receiving antennas, cable
television equipment, GPS equipment, pagers, cellular phones, mobile communications equipment, and
radio and television studio and broadcasting equipment.”8 The SBA has developed a small business size
standard for Radio and Television Broadcasting and Wireless Communications Equipment
Manufacturing, which is: all such firms having 750 or fewer employees. According to Census Bureau
data for 2007, there were a total of 939 establishments in this category that operated for part or all of the
entire year. Of this total, 912 had less than 500 employees and 17 had more than 1000 employees.9 Thus,
under that size standard, the majority of firms can be considered small.

D.

Description of Projected Reporting, Record Keeping, and Other Compliance
Requirements

4. The NPRM proposes to establish a 12-month timetable after the effective date of any new or
modified rules that we eventually decide to adopt in this proceeding for manufacturers to produce U-NII
devices that comply with new or modified rules. We also propose to establish a 2-year timetable after the
effective date of any or modified rules for requiring that any U-NII devices manufactured in or imported
into the United States for sale comply with the new or modified rules. We believe that a 12-month
transition period should provide sufficient time for manufacturers to design equipment that complies with
any new or modified rules and to obtain equipment certification. Therefore, we would provide
transitional provisions in our rules to allow for certification of U-NII devices under the current rules for
up to 12 months after the new or modified rules are published in the Federal Register. Beginning 12
months after the effective date of the new or modified rules, equipment certification could no longer be
obtained for U-NII devices that do not meet the new requirements. However, until the end of the 2-year
transition period, we would permit Class II permissive changes for equipment certified prior to the 12-
month transition date10 as well as their continued manufacture, marketing, installation, and importation.
After the end of the 2-year transition period, Class II permissive changes for such devices would not be
permitted nor would their manufacture, marketing, installation, or importation. We find that these
requirements would facilitate the transition to new requirements without unduly impairing the availability
or cost of U-NII devices or imposing undue burdens on manufacturers, translation services providers, or
the public.

E.

Steps Taken to Minimize Significant Economic Impact on Small Entities, and
Significant Alternatives Considered

5. The RFA requires an agency to describe any significant alternatives that it has considered in
reaching its proposed approach, which may include the following four alternatives (among others): (1) the
establishment of differing compliance or reporting requirements or timetables that take into account the
resources available to small entities; (2) the clarification, consolidation, or simplification of compliance or
reporting requirements under the rule for small entities; (3) the use of performance, rather than design,

7 15 U.S.C. § 632.
8 The NAICS Code for this service 334220. See 13 C.F.R 121/201. See also
http://www.census.gov/econ/industry/current/c334220.htm.
9 See http://factfinder2.census.gov/bkmk/table/1.0/en/ECN/2007_US/31SG3//naics~334220.
10 See 47 C.F.R. § 2.1043(b)(2).
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standards; and (4) an exemption from coverage of the rule, or any part thereof, for small entities.11
The proposals contained in this Notice of Proposed Rulemaking (NPRM) are aimed at improving the
sharing of the spectrum between U-NII devices and other spectrum users. This NPRM proposes to amend
Part 15 of our rules governing the operation of Unlicensed National Information Infrastructure (U-NII)
devices in the 5 GHz band.12 U-NII devices are unlicensed intentional radiators that operate in the
frequency bands 5.15-5.35 GHz and 5.47-5.825 GHz, and which use wideband digital modulation
techniques to provide a wide array of high data rate mobile and fixed communications for individuals,
businesses, and institutions.13 Since the Commission first made available spectrum in the 5 GHz band for
U-NII in 1997, we have gained much experience with these devices. We believe that the time is now
right for us to revisit our rules, and, in this NPRM, we propose to modify certain technical requirements
for U-NII devices to ensure that these devices do not cause harmful interference and thus can continue to
operate in the 5 GHz band and make broadband technologies available for consumers and businesses.
We also seek comment on making available an additional 195 megahertz of spectrum in the 5.35-5.47
GHz and 5.85-5.925 GHz bands for U-NII use. This could increase the spectrum available to unlicensed
devices in the 5 GHz band by approximately 35 percent and would represent a significant increase in the
spectrum available for unlicensed devices across the overall radio spectrum. The initiation of this
proceeding satisfies the requirements of Section 6406 (a) of the “Middle Class Tax Relief and Job
Creation Act of 2012” which requires the Commission to begin a proceeding to modify part 15 of title 47,
Code of Federal Regulations, to allow unlicensed U-NII devices to operate in the 5350-5470 MHz band.14
We believe that an increase in capacity gained from 195 megahertz of additional spectrum, combined
with the ease of deployment and operational flexibility provided by our U-NII rules, would continue to
foster the development of new and innovative unlicensed devices, and increase wireless broadband access
and investment.

F.

Federal Rules that May Duplicate, Overlap, or Conflict With the Proposed Rule

6. None.

11 See 5 U.S.C. § 603(c).
12 See 47 C.F.R. Part 15 Subpart E – Unlicensed National Information Infrastructure Devices.
13 See 47 C.F.R. § 15.403(s).
14 See Middle Class Tax Relief and Job Creation Act of 2012, Pub. L. No. 112-96, § 6406, 126 Stat. 156, 231
(2012), 47 U.S.C. § 1453 (Spectrum Act).
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STATEMENT OF CHAIRMAN

JULIUS GENACHOWSKI

Re:
Revision of Part 15 of the Commission’s Rules to Permit Unlicensed National Information
Infrastructure (U-NII) Devices in the 5 GHz band, ET Docket No. 13-49.

Most everyone in this room or watching at home has had a direct experience with the problem
we’re seeking to solve.
You’re at an airport, a convention, or hotel and you break out your laptop, tablet, or smartphone,
hoping you can get a Wi-Fi connection.
One moment you’re saying, “Great, I can get online.” Moments later, you’re saying, “Not so fast,”
literally.
Wi-Fi congestion is a very real and growing problem. Like licensed spectrum, demand for
unlicensed spectrum threatens to outpace supply. The core challenge is the dramatically increased use of
wireless devices, which require spectrum.
Recently published data from Cisco estimates that commercial wireless networks are already
offloading 33% of all traffic to Wi-Fi and project that offloading will grow to 46% by 2017.
So while Wi-Fi offload is part of the solution to the problem of congested cellular networks, Wi-
Fi’s popularity is creating congestion issues of its own.
And Wi-Fi congestion isn’t just a problem at airports or public venues. It’s becoming a problem in
the home, where it’s increasingly common to have multiple data-hungry devices using Wi-Fi at the same
time.
For the past few years, the Commission has been pursuing a strong agenda to free up both licensed
and unlicensed spectrum for broadband. We have been and will continue to be relentless in our work to
free up spectrum, and we will lean into every opportunity that can meet the country’s spectrum needs.
We’re moving forward with world-leading policies, like freeing up spectrum for auctions to
unleash very large amounts of licensed spectrum for our commercial wireless networks – a very high
priority.
Spectrum auctions have had, and will continue to have, a huge positive impact on our economy and
lives.
And as part of the incentive auctions proceeding, we’re also paving the way for next-generation
Wi-Fi by ensuring for the first time that low-band unlicensed spectrum will be available on a nationwide
basis, using consistent frequencies.
Today, the FCC takes a big step to ease congestion on traditional Wi-Fi networks, which will mean
faster speeds and fewer headaches for U.S. consumers.
Unlicensed spectrum is also a great success story for both the FCC and the U.S. economy.
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In the 1980s, the FCC became the world’s first agency to make available unlicensed spectrum
suitable for WiFi-type uses, meaning anyone could use it as long as they follow basic rules to prevent
interference. The use of this unlicensed spectrum sparked innovative technologies like Bluetooth and,
perhaps most notably Wi-Fi.
These technologies have spurred job creation and economic growth – hundreds of billions of
dollars of value creation for our economy and consumers, resulting in billions of dollars to the Treasury.
We must keep nurturing today’s Wi-Fi, as we also continue to be forward-looking, and develop the
next generation of unlicensed spectrum use policies.
Today’s proposal would modify the rules to make the existing unlicensed 5GHz spectrum more
usable, and to provide access to additional new unlicensed spectrum in that band.
Specifically, the proposal would increase and free up the unlicensed spectrum available for ultra-
high-speed, high-capacity Wi-Fi – known as “Gigabit Wi-Fi” – by up to 35 percent – from 555 megahertz
to 750 megahertz of spectrum: the largest block of unlicensed spectrum to be made available for
expansion of Wi-Fi since 2003.
This additional spectrum will increase speeds and alleviate Wi-Fi congestion at major hubs, such as
airports, convention centers and large conference gatherings.
In addition, this would also increase speed and capacity for Wi-Fi in the home where multiple users
and devices are often on the network at the same time.
Because the 5GHz band is already used for other purposes by both federal and non-federal users,
the effort will require significant consultation with stakeholders to enable non-interfering shared use of
the spectrum.
But consultation can’t be an excuse for inaction or delay.
We must all be guided by the President's directive to free up spectrum for commercial use, and by
the critical importance of increasing the availability of spectrum to drive economic growth, job creation,
and our country's global competitiveness.
These are goals and interests we all share. We must pursue all ideas to accelerate freeing up
spectrum.
We are committed to a process of consultation, and we’re also committed to moving expeditiously
to free up additional spectrum for Wi-Fi. We look forward to working with all government and non-
government stakeholders.
Thank you to OET, WTB, EB, IB and OGC for your excellent work on this item, and Renee
Gregory in my office.
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STATEMENT OF

COMMISSIONER ROBERT M. McDOWELL

Re:
Revision of Part 15 of the Commission’s Rules to Permit Unlicensed National Information
Infrastructure (U-NII) Devices in the 5 GHz band, ET Docket No. 13-49.

Last night, I had the privilege of attending the National Academy of Engineering Awards
ceremony. There is no Nobel Prize for engineering, so these awards are intended to fill that gap.
Included in the amazing array of honorees was my friend Marty Cooper, the inventor of the cell phone.
Also in attendance was Dr. Robert Kahn, whom I also have gotten to know over the years. Dr. Kahn is
the co-inventor of TCP/IP, the protocol that allows the Internet to work.
It ends up that Marty Cooper and Bob Kahn were fans of each other but had never met. Last
night, I had the incredible honor of being able to introduce them to each other. Although I still haven’t
recovered from the awe of the moment where an Internet pioneer met the father of the cell phone – quite
literally the personification of the Internet meeting mobility – I was able to ask each of them at once
whether, at the time of their inventions, they had foreseen the incredible effect their work would have on
the human condition. With characteristic honesty and humility, they both said “no.”
The point for all of us to learn from these great minds is that none of us can guess what
innovations may be coming over the horizon or their potential to improve the lives of all human beings.
Liberal arts majors who make public policy, such as myself, should learn to exercise regulatory humility
and allow engineers to have the freedom to experiment. I am hopeful that this proceeding does just that.
Marty’s and Bob’s inventions are doing just fine. In fact, in 2012, U.S. mobile data traffic
reached 207 petabytes per month, a 62 percent increase over the previous year. To put this amazing
growth into context, processing 207 petabytes per month is equivalent to watching 52 million DVDs per
month or sending 570 million text messages each second over our wireless networks.15 And mobile usage
will only continue to surge well into the future. It is estimated that mobile data traffic will grow nine fold
in the next five years.16 Furthermore, wireless devices are proliferating at an unprecedented rate. Fifty-
one million new devices were connected to U.S. mobile networks in the last year alone to bring the total
of American mobile-enabled devices to 424 million. It is estimated that 775 million wirelessly-connected
devices will be used by Americans in 2017.17
To relieve congested cell networks, consumers are choosing to move wireless data to unlicensed
systems. Last year, 96 percent of U.S. traffic associated with portable devices was carried on Wi-Fi
networks at some point. Not only does this percentage include data that originated on Wi-Fi systems, but
also the 47 percent of mobile data that was offloaded from cellular to Wi-Fi networks.18 What does this

15 VNI Mobile Forecast Highlights, 2012-2017, United States – 2012 Year in Review, CISCO SYSTEMS,
http://www.cisco.com/web/solutions/sp/vni/vni_mobile_forecast_highlight/index.html (last visited Feb. 20, 2013)
(filter by country to obtain information for the United States and select 2012 Year in Review).
16 VNI Mobile Forecast Highlights, 2012-2017, United States – 2017 Forecast Highlights, CISCO SYSTEMS,
http://www.cisco.com/web/solutions/sp/vni/vni_mobile_forecast_highlight/index.html (last visited Feb. 20, 2013)
(filter by country to obtain information for the United States and select 2017 Forecast Highlights).
17 VNI Mobile Forecast Highlights, 2012-2017, United States – Network Connections, CISCO SYSTEMS,
http://www.cisco.com/web/solutions/sp/vni/vni_mobile_forecast_highlight/index.html (last visited Feb. 20, 2013)
(filter by country to obtain information for the United States and select 2017 Network Connections).
18 Id. (select Offload Traffic).
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mean? The spectrum that is used for unlicensed Wi-Fi is also experiencing congestion, which will only
increase in the coming years if we do not make appropriate bands, like the 5 GHz band, more attractive
for investment and innovation.
Accordingly, I am pleased to vote in support of this notice which initiates the review of the
current requirements and takes steps to increase the amount of spectrum available for unlicensed use in
the 5 GHz band. Our proposals to harmonize the rules and requirements across the 5 GHz band will make
this spectrum more attractive to investors and innovators by providing certainty and consistency across a
wide swath of spectrum. This initiative, combined with the proposal to permit unlicensed use on an
additional 195 megahertz of spectrum, will make the 5 GHz band more attractive for the deployment of
faster, more robust Wi-Fi networks using the latest industry standards that provide the greatest
efficiencies on 80 to 160 megahertz slices of spectrum. I am also pleased that we specifically seek
comment on international efforts to harmonize uses of the 5 GHz band.
Launching this proceeding is just the beginning, of course, and we have a lot of work ahead us.
Federal and non-federal primary users are prevalent throughout the 5 GHz band – both in the bands where
unlicensed use is already permitted, and in the 195 megahertz of spectrum we hope to open to such use.
Today, we take the initial steps to fulfill Congress’s mandate in the Spectrum Act that we, along with
NTIA, look into opening certain 5 GHz frequencies for unlicensed use.19 Although we seek comment on
protecting incumbent licensees from harmful interference, the Commission, affected government
agencies, Wi-Fi providers and others will have to work together to ensure the successful unlicensed
deployment of this spectrum.
Although allowing unlicensed use in an additional 195 megahertz of spectrum will promote
continued innovation and investment in unlicensed devices and wireless broadband systems, it does not
mean that we can be complacent and stop advocating for additional federal spectrum to be auctioned for
exclusive use licenses. The federal government, specifically the executive branch, needs to evaluate its
spectrum usage with the goal of relinquishing bandwidth for exclusive and flexible private sector uses.
Spectrum “sharing” and the auctioning of exclusive use licenses are not equivalent.
I thank the Chairman for prioritizing this important proceeding. I also thank the dedicated and
tireless staff of the Office of Engineering and Technology for all of their work in preparing this notice and
for all of their efforts to come in opening up the 5 GHz band for new and improved unlicensed use and
opportunities that will benefit Americans.

19 See Middle Class Tax Relief and Job Creation Act of 2012, Pub. L. No. 112-96, 126 Stat. 156 (2012).
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STATEMENT OF

COMMISSIONER MIGNON L. CLYBURN

Re:
Revision of Part 15 of the Commission’s Rules to Permit Unlicensed National Information
Infrastructure (U-NII) Devices in the 5 GHz band, ET Docket No. 13-49.

In his State of the Union Address, President Obama spoke of “a smarter government that sets
priorities and invests in broad-based growth.” Our first priority, he said should be “making America a
magnet for new jobs and manufacturing.” Without a doubt, the wireless service industry is one sector
where smart policy can promote tremendous growth. One wireless analyst stated that, in 2011, this
industry was responsible for 3.8 million jobs, or 2.6 percent of all domestic employment. According to
other reports, the wireless industry now contributes, more to our nation’s GDP, than the agriculture,
hotels and lodging, air transportation, and motor vehicle manufacturing industries. In light of all the
wireless industry brings to our economy, promoting growth in this sector can greatly advance the
President’s domestic policy goals.
Under Chairman Genachowski’s leadership, the Commission has been adopting innovative
policies to promote broader deployment and adoption of mobile broadband services. These include the
data roaming order, the TV White Spaces proceeding, the interoperability in the lower 700 MHz band
proceeding, mHealth initiatives, and the Learning On The Go pilot program. This proceeding to promote
unlicensed services, in the 5 GHz band, is another prime example of how smart government policy can
advance growth in the wireless industry and the overall economy.
When the FCC first allocated unlicensed spectrum, in the 1980s, it was primarily used for
cordless phones, baby monitors, and garage door openers. Then Wi-Fi hit the scene and the demand has
been off the charts. In 2005, “tens of millions” of Wi-Fi devices were sold globally. In 2011, at least 150
million of those devices were sold only in the U.S. Unlicensed Wi-Fi offload is now an integral part of
the way mobile carriers deliver their services. In 2011, Consumer Federation of America found that Wi-
Fi offload allows wireless carriers to save more than $25 billion per year, in deployment costs. According
to some commenters, the annual contribution of the unlicensed wireless sector to our Nation’s economy is
estimated to be more than $50 billion per year.
The Nation’s demand for unlicensed services has increased so dramatically that we need more
spectrum to support these services. The 2.4 GHz band, while critical to the success of Wi-Fi and other
unlicensed technologies, is increasingly congested particularly in major cities. Densely populated centers
are the most expensive geographic areas to deploy licensed networks.
Therefore, I commend the staff, for recommending rule proposals that could make up to an
additional 195 megahertz of spectrum, available for unlicensed services. I hope commenters will provide
us with thoughtful detailed recommendations on how we can adopt technical rules that will create
incentives for the industry to make the most efficient use of this spectrum. As the item points out, there
are a number of technical issues to be resolved and we will have to coordinate with NTIA on the impact
of these proposed rules on federal users in the 5 GHz band. But it is important that we get started on
resolving these issues right away. The sooner we solve these issues, the sooner American innovation can
show leadership in developing this band for unlicensed services.
Special thanks are due to Julie Knapp, Mark Settle, Aole Wilkins, and the other talented
members, of OET, the Enforcement, International, and Wireless Bureau, for presenting us with an
excellent NPRM.
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STATEMENT OF

COMMISSIONER JESSICA ROSENWORCEL

Re:
Revision of Part 15 of the Commission’s Rules to Permit Unlicensed National Information
Infrastructure (U-NII) Devices in the 5 GHz band, ET Docket No. 13-49.

Look around. The wireless devices we pull to our ears, place in our pockets, tap on our laps, read
with at night, and hover over our desks at day—they are multiplying. We own more of them, do more
with them, and power more aspects of our lives with them than ever before. We are a nation whose every
day depends on wireless connectivity. It is an essential part of our economic and civic life.
So it is no surprise that the demand for our airwaves is growing at a fast clip. But it is important
to remember that the speed with which we face demand for our spectrum is not confined to licensed
wireless services. Congestion in our unlicensed spectrum bands is fast approaching a breaking point, too.
Why does this coming crush in unlicensed spectrum matter?
For starters, the unlicensed economy represents economic growth. Today, unlicensed wireless
devices contribute between $16-37 billion to our economy annually. To put that in perspective, that is
more than Americans spend on milk and bread each year, combined.
The unlicensed economy also represents innovation. Countless innovations that have made our
lives easier and more convenient every day are dependent on unlicensed spectrum. If you have ever
called on a cordless phone, changed the channel with a television remote, or pushed the button on a
garage door opener, you have benefited from the power of unlicensed technology.
The unlicensed economy also represents a critical pathway for Internet connectivity. Today,
more than one third of wireless data connections are offloaded onto unlicensed spectrum. Most of that
traffic uses the 2.4 GHz band, which is also the home of countless other devices, like cordless phones,
microwave ovens, and Bluetooth. Although the 2.4 GHz band continues to serve us well, it is becoming
mighty crowded.
So it is no wonder that the search is on to find more spectrum for unlicensed services. It is a
search that this Commission needs to support, consistent with the law. Because good spectrum policy
requires both licensed and unlicensed services—across multiple spectrum bands.
The proposals we make in this rulemaking regarding the 5 GHz band are good first steps. These
are ideas that can mean new near-term opportunities for unlicensed and long-term possibilities for
expanding unlicensed down the road.
Let us start with what we can do today. This rulemaking explores how to synchronize the varying
technical restrictions in place throughout the 5 GHz bands, while still respecting existing government and
commercial users. In practice, this means working to expand to more 5 GHz frequencies the kind of
flexible rules that have been the script for an unlicensed success story in the 5.725-5.825 GHz band. As a
result of these flexible rules, cable operators right now use this band to offer Wi-Fi services at hotspots in
their franchise areas, allowing consumers to take their broadband with them when they leave the house.
This means consumers can save money and reduce congestion on licensed wireless networks. So we
should explore whether or not restrictions impeding the expansion of unlicensed in other 5 GHz bands are
still necessary. At the same time, this investigation can include asking whether parts of the 5 GHz band
are appropriate for other federal services. But once those questions are answered, we should not hesitate
to remove limitations that are no longer needed.
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Fast forward from what we can do now to what we may be able to do down the road. Consistent
with the direction from Congress in the Middle Class Tax Relief and Job Creation Act, we are proposing
to make an additional 195 megahertz in the 5 GHz band available for unlicensed use. These airwaves can
be a colossal catalyst for new innovation, because it features enough continuous spectrum to unlock the
full potential of a new Wi-Fi standard, 802.11ac. Undoubtedly, cool new ways of connecting await.
But as enticing as it is to be swept away by that future promise, we must deal with present
realities. These 195 megahertz are occupied by federal users. The National Telecommunications and
Information Administration reports that additional testing of this spectrum will take at least until the end
of 2014. Plus, the types of uses that have been proposed in this spectrum will require resources like new
databases, dynamic frequency selection, and transmit power control. In short, finding ways to share this
195 megahertz of spectrum without interfering with critical government missions may take a long time.
So I think it is necessary to start identifying ways to accelerate this process by incentivizing
federal authorities to be more efficient with spectrum right now. To do this, we must look for ways that
federal users can realize value from using spectrum efficiently instead of only seeing loss from its
commercial reallocation. These incentives need not be purely financial. And the rewards do not have to
come directly from the spectrum rights being released. Instead, the incentives can come from benefits in
appropriations, budgeting, or through structured use of synthetic currency, as proposed by the President’s
Council of Advisors on Science and Technology.
When it comes to transitioning spectrum from strictly federal to new or shared commercial use,
we need not only use sticks—we should explore carrots. I think the latter is bound to facilitate more
opportunity in the 5 GHz spectrum—and beyond. Given the multiplying number of wireless devices in
our lives and the growing demands on our airwaves—licensed and unlicensed—now is not a moment too
soon.
Thank you to the Office of Engineering and Technology for your hard work on this rulemaking
and great dedication to these issues.
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FCC 13-22

STATEMENT OF

COMMISSIONER AJIT PAI

Re:
Revision of Part 15 of the Commission’s Rules to Permit Unlicensed National Information
Infrastructure (U-NII) Devices in the 5 GHz band, ET Docket No. 13-49.

Flexible unlicensed spectrum use was one of this country’s great innovations in the 1980s. The
Commission expanded several so-called “junk” bands to permit additional unlicensed uses and
streamlined the Part 15 rules accordingly. Unlicensed spectrum in the 2.4 GHz and 5 GHz bands is now
some of the most valuable spectrum in the world for broadband. And consumers are the ultimate
beneficiaries of unlicensed-use technologies such as Wi-Fi and Bluetooth. Millions of Americans rely on
Wi-Fi every day to connect their laptops, their smartphones, and their tablets to the Internet. And in the
words of The Big Bang Theory’s Sheldon Cooper: “Everything is better with Bluetooth.”
What excites me about today’s Notice of Proposed Rulemaking is that we are building on these
past successes and using spectrum ideally suited for unlicensed use. The short-range propagation
characteristics of 5 GHz spectrum enable localized reuse with minimal risk of interference. The next-
generation Wi-Fi standard, IEEE 802.11ac, will be finalized soon. Manufacturers are already building
devices to work on 5 GHz spectrum. And enhancing the contiguity and size of the 5 GHz blocks
contemplated in the item should allow wider channels for higher bandwidth transmissions. For example,
a 160 MHz-wide channel could deliver 1 gigabit of data per second. That’s “Super Wi-Fi.”
I am most pleased that today we are teeing up the expansion of unlicensed use by a full 195 MHz
in the 5 GHz band. I have called on the Commission to do so since October.20 We were not obligated to
go this far—the Spectrum Act only required that we commence a proceeding on opening up 120 MHz21—
but taking this step just makes sense. More spectrum will allow higher-speed, higher-capacity
connections and will mean less congestion in apartment buildings and coffee shops, libraries and offices.
For all these reasons, putting these bands to better commercial use could have tremendous benefits.
Achieving this vision will not be without its challenges. The statute lets us expand unlicensed use
into the 5350–5470 MHz band only if we determine that “licensed users will be protected by technical
solutions, including use of existing, modified, or new spectrum-sharing technologies and solutions.” We
also must find that “the primary mission of Federal spectrum users . . . will not be compromised by the
introduction of unlicensed devices.”22 To help us in these tasks, the National Telecommunications and
Information Administration (NTIA) has reported on the potential impacts to federal government users
from expanding unlicensed use.23 And I appreciate their work. But Congress gave the FCC the ultimate
responsibility, so I look forward to reviewing comments with an open mind. Given the wide swaths of
spectrum already allocated to the federal government, I hope that we will consider whether Federal users
should alter their systems or operations to accommodate unlicensed devices in this spectrum24 and what
solutions will work, keeping in mind the costs and benefits of all potential options.

20 Remarks of Commissioner Ajit Pai at CTIA’s MobileCon (Oct. 10, 2012), http://go.usa.gov/4tkA; see also
Statement of Ajit Pai, Commissioner, Federal Communications Commission, Hearing before the Subcommittee on
Communications and Technology of the U.S. House of Representatives Committee on Energy and Commerce (Dec.
12, 2012), http://go.usa.gov/4t8Q.
21 Middle Class Tax Relief and Job Creation Act of 2012, § 6406(a)(1).
22 Id. § 6406(a)(2).
23 NTIA, Evaluation of the 5350–5470 MHz and 5850–5925 MHz Bands Pursuant to Section 6406(b) of the Middle
Class Tax Relief and Job Creation Act of 2012 (Jan. 2013), available at http://go.usa.gov/4tZH.
24 See id. at ii (“NTIA assumed that the federal agencies will not alter their systems or operations to accommodate
U-NII devices on a shared basis in the potential 5 GHz expansion bands.”).
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Today’s Notice is just the beginning of what will surely be a highly technical process. Suffice it
to say that the Commission could not do it without the support of the Office of Engineering Technology,
especially Julius Knapp, Bruce Romano, Aole Wilkins, Geraldine Matise, Mark Settle, Karen Ansari, and
Navid Golshahi. Thank you for your work on this item and for all the work you do each day to advance
the FCC’s mission.
59

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