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Tank Level Probing Radars

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Released: January 15, 2014

Federal Communications Commission

FCC 14-2

Before the

Federal Communications Commission

Washington, D.C. 20554

)
In the Matter of
)
)

Amendment of Part 15 of the Commission’s
)
ET Docket No. 10-23
Rules To Establish Regulations for Tank Level
)
Probing Radars in the Frequency Band
)
77-81 GHz
)
)

Amendment of Part 15 of the Commission’s
)
Rules To Establish Regulations for Level Probing )
Radars and Tank Level Probing Radars in the
)
Frequency Bands 5.925-7.250 GHz,
)
24.05-29.00 GHz and 75-85 GHz
)
)

Ohmart/VEGA Corp., Request for Waiver of
)
ET Docket No. 10-27
Section 15.252 to Permit Marketing of Level
)
Probing Radars in the 26 GHz Band
)

REPORT AND ORDER and ORDER

Adopted: January 15, 2014

Released: January 15, 2014
By the Commission:

TABLE OF CONTENTS

Heading
Paragraph #
I. INTRODUCTION.................................................................................................................................. 1
II. BACKGROUND.................................................................................................................................... 4
III. REPORT AND ORDER ...................................................................................................................... 13
A. Certification under Section 15.209 ................................................................................................ 17
B. New Section 15.256....................................................................................................................... 21
1. Frequency Bands of Operation................................................................................................ 21
a. 5.925-7.250 GHz frequency band..................................................................................... 22
b. 24.05-29.0 GHz frequency band....................................................................................... 25
c. 75-85 GHz frequency band............................................................................................... 26
2. Technical Requirements .......................................................................................................... 31
a. Radiated Emission Limits................................................................................................. 33
a. Antenna Requirements...................................................................................................... 41
(i) Antenna Beamwidth ......................................................................................................... 42
(ii) Antenna Side-Lobe Gain................................................................................................... 45
b. Automatic Power Control ................................................................................................. 49
3. Other Requirements................................................................................................................. 50
a. Operational and Marketing Restrictions ........................................................................... 50
a. Equipment Certification.................................................................................................... 57
b. Additional Protection for the Radio Astronomy Service (RAS)....................................... 59

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IV. ORDER ................................................................................................................................................ 65
V. PROCEDURAL MATTERS................................................................................................................ 67
VI. ORDERING CLAUSES....................................................................................................................... 70
APPENDIX A - Final Regulatory Flexibility Analysis
APPENDIX B - Parties Submitting Comments
APPENDIX C - Antenna Side-Lobe Gain
APPENDIX D - Final Rules

I.

INTRODUCTION

1.
By this action, we modify Part 15 of our rules for level probing radars (LPRs)
operating on an unlicensed basis in the 5.925-7.250 GHz, 24.05-29.00 GHz, and 75-85 GHz bands to
revise our measurement procedures to provide more accurate and repeatable measurement protocols
for these devices. LPR devices are low-power radars that measure the level (relative height) of
various substances in man-made or natural containments. In open-air environments, LPR devices
may be used to measure levels of substances such as water basin levels or coal piles. An LPR device
that is installed inside an enclosure, which could be filled with liquids or granulates, is commonly
referred to as a tank level probing radar (TLPR). LPR (including TLPR) devices can provide accurate
and reliable target resolution to identify water levels in rivers and dams or critical levels of materials
such as fuel or sewer-treated waste, reducing overflow and spillage and minimizing exposure of
maintenance personnel in the case of high risk substances.1
2.
LPR devices have operated for years under the general technical standards for
intentional radiators in Section 15.209 of the Commission’s rules, primarily inside metal or concrete
tanks which substantially attenuate radio frequency energy from the LPR antenna.2 Although we will
continue to certify LPR under this rule, manufacturers have had a difficult time demonstrating
compliance with the rule’s low emission limits for certain types of level-measuring applications in
fiberglass or polyethylene (plastic) tanks or in open air. Such difficulty occurs because reflections off
of the surfaces being measured attenuate inconsistently due to devices’ orientation and the material
being measured, the physical shape of which can change continuously depending on the material and
circumstances. Thus, it is difficult to make a measurement that will validly apply to all installations
of a given LPR device when measuring LPR emissions in situ for certification purposes. The
amended rules adopted in this Report and Order would establish a comprehensive and consistent
approach that would provide simplicity and predictability for authorizing LPRs for level-measuring
applications in any type of tank or open-air environments, in the following frequency bands:
5.925-7.250 GHz, 24.05-29.00 GHz, and 75-85 GHz. 3 Certification of LPR equipment under the new
rules will require measuring emissions in the main beam of the LPR antenna, while adjusting the
emission limits in Part 15 for devices so measured to account for the significant attenuation that
occurs upon reflection of those emissions. These emission limits will protect any nearby receivers
from encountering any increase in interfering signal levels. The new rules will benefit the public and
industry by improving the accuracy and reliability of these measuring tools, and providing needed
flexibility and cost savings for LPR device manufacturers which should in turn make them more

1 Over-filling of plant equipment can damage machinery, threaten workers’ safety, and cause environmental
damage. Under-filling of equipment such as rock crushers or lubricant reservoirs can result in machinery running
empty or dry, leading to severe product or machinery damage and collateral worker injury.
2 47 C.F.R. § 15.209. This rule section permits any type of unlicensed intentional radiator to operate in any
frequency band, other than “restricted” bands identified in 47 C.F.R. § 15.205(a), as long as it complies with the
general radiated emission limit and associated technical provisions.
3 Consistent with 47 C.F.R. § 15.215(a), the regulations adopted herein in new Section 15.256 “…provide
alternatives to the general radiated emission limits for intentional radiators operating in specified frequency bands.”
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available to users, without causing harmful interference to authorized services. To the extent
practicable, these amended rules harmonize our technical rules for LPR devices with similar
European standards, thus improving the competitiveness of U.S. manufacturers in the global
economy.
3.
In the Order, we also dismiss as moot a request by VEGA Americas, Inc. (formerly
Ohmart/VEGA Corporation) (VEGA)4 to waive the use restrictions in Section 15.252 so that it can
operate an LPR device in the 26 GHz band.5

II.

BACKGROUND

4.
Traditionally, measuring the level of various materials is accomplished using a
variety of mechanical devices such as differential-pressure tools, air bubblers, and displacers. In
contrast, LPRs take such measurements with technology-based tools that employ radio frequency
(RF) signals. More specifically, LPR devices are downward-looking low-power transceivers that can
operate either inside a tank (or similar enclosure) or in an open-air environment, e.g., mounted under
a bridge to measure water levels in a basin/river or under a roof structure to measure mounds of
granulates such as coal. An LPR device is typically mounted at the top of an enclosure or on a
support rail and emits RF signals from an antenna aimed downwards at the surface of the substance
below. The device measures or calculates the time delay between the transmitted signal and the
return echo reflected off the surface of the substance being measured to determine the substance’s
level.
5.
Most LPR devices on the U.S. market currently operate on an unlicensed basis at 6 GHz,
24 GHz, or 26 GHz under the Section 15.209 general emission limits for intentional radiators. LPR
devices operate at different frequency bands according to the type of substance being measured and the
installation. For example, LPR devices operating in the 6 GHz frequency range are often used for
applications where the substance to be measured may have high dust content or severe foaming
characteristics; because the dust or foam is made up of relatively large particles, these substances tend to
scatter a higher frequency signal. A relatively low frequency, therefore, is necessary to penetrate the
surface below. LPR devices operating in the 24-26 GHz frequency range can accommodate a wide
variety of applications but are less effective on foam, turbulent materials, or substances that tend to
generate condensation or dust. LPR devices operating at even higher frequencies, i.e., above 30 GHz in
the “millimeter wave” spectrum,6 could be very effective in applications where access is limited because
they can employ smaller antennas.7 Smaller antennas can accommodate existing small connection flanges
more easily, enabling the radar to be installed in tighter spaces and in smaller enclosures than is possible
with LPR devices operating at lower frequencies.8
6.
Existing technology typically uses either traditional pulsed modulation techniques or
frequency-modulated continuous waves (FMCW), typically producing bandwidths greater than or equal
to 50 megahertz. With a pulsed-modulated LPR, short duration pulses are transmitted toward the target,
and the target distance is calculated using the pulse transit time. With an FMCW-modulated LPR, a
continuous frequency-modulated signal is transmitted, and the frequency difference caused by the time

4 See VEGA’s request for waiver, Public Notice DA 10-128, ET Docket No. 10-27 (rel. Jan. 26, 2010).
5 47 C.F.R. § 15.252.
6 The term “millimeter wave” arises from the fact that the wavelength of radio signals operating on frequencies
between 30 GHz and 300 GHz ranges from 10 millimeters to 1 millimeter, respectively.
7 Part 15 rules do not currently permit unlicensed operation above 38.6 GHz, except in certain specific frequency
bands. See 47 C.F.R. §§ 15.205(a), 15.253, 15.255 and 15.257.
8 As the frequency increases, the wavelength decreases and antennas operating at higher frequencies in most cases
are physically smaller than those operating at lower frequencies.
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delay between transmission and reception indicates the target distance. To conserve power, LPR devices
operate with a low duty cycle: 20 percent or below for FMCW and much lower for pulsed LPR
emissions. LPR devices do not communicate with one another, and there is minimal likelihood that two
or more devices will emit simultaneously within close proximity of one another.
7.
To date, the Commission has authorized LPR devices primarily for use in enclosed tanks
upon demonstration of compliance with Section 15.209 of the rules, which specifies an average
Equivalent Isotropic Radiated Power (EIRP) limit of -41.3 dBm for operations above 960 MHz.9 In
addition, Section 15.35(b) of the rules sets a peak limit at 20 dB above the average limit, e.g., a peak
EIRP limit of -21.3 dBm.10 For pulsed signals, it may be necessary to take into account the limitation of
the measurement instrumentation to determine the total peak power level, through the use of a pulse
desensitization correction factor (PDCF).11 Therefore, pulsed LPR devices often must reduce their peak
power output in order to comply with the peak emission limit in Section 15.209 and thus may sacrifice the
precision and accuracy required by certain applications. LPR devices using other modulation techniques,
e.g., FMCW, also need wider bandwidth in certain frequency ranges (e.g., above 40 GHz frequency
range) to achieve higher measurement precision.
8.
Because some LPR devices need higher power within their main antenna beam and wider
bandwidth than permitted under Section 15.209 to achieve performance objectives for certain
level-measuring applications, LPR manufacturers also have considered whether they could operate under
other Part 15 rules applicable to wideband devices, i.e., those employing a bandwidth greater than
10 megahertz. Those rules allow higher peak-to-average power ratios than are permitted by Section
15.35(b) and specify a power limit in terms of power spectral density rather than total peak power, thus
eliminating the need to apply a PDCF.12 Section 15.250 permits operation in the 5.925-7.250 GHZ band
but prohibits “fixed outdoor infrastructure.”13 Section 15.252 only permits operation of radars mounted in
terrestrial transportation vehicles in the 16.2-17.7 GHz and 23.12-29.0 GHz bands.14 Because of these
various frequency and operational restrictions, LPR devices currently cannot be certified to operate under
either of these alternative wideband rules without grant of a waiver.
9.
On January 14, 2010, the Commission adopted the Notice and Order in this proceeding.15
The Notice and Order proposed to modify Part 15 of the rules to allow the restricted 77-81 GHz

9 47 C.F.R. § 15.209.
10 47 C.F.R. § 15.35(b).
11 Amendment of Part 15 of the Commission’s Rules To Establish Regulations for Tank Level Probing Radars in the
Frequency Band 77-81 GHz and Amendment of Part 15 of the Commission’s Rules To Establish Regulations for
Level Probing Radars and Tank Level Probing Radars in the Frequency Bands 5.925-7.250 GHz, 24.05-29.00 GHz
and 75-85 GHz, Further Notice of Proposed Rulemaking,
ET Docket 10-23, 27 FCC Rcd 3660, 3666-67, para. 7
(2012) (FNPRM). A PDCF is an adjustment factor that must be added to the indicated value of a pulsed emission on
a spectrum analyzer when the emission bandwidth of the pulse exceeds the resolution bandwidth of the analyzer.
12 Wideband devices are required to comply with a peak limit based on power density in a specific bandwidth, not a
total peak limit over their entire operating frequency range. Both Sections 15.250 and 15.252 permit a maximum
peak emission limit of 0 dBm as measured in a 50-megahertz resolution bandwidth. 47 C.F.R. §§ 15.250 and
15.252.
13 47 C.F.R. § 15.250.
14 47 C.F.R. § 15.252.
15 See Amendment of Part 15 of the Commission’s Rules To Establish Regulations for Tank Level Probing Radars in
the Frequency Band 77-81 GHz, Notice of Proposed Rulemaking and Order
, ET Docket Nos. 10-23, 06-216 and
07-96, 25 FCC Rcd 601 (2010) (Notice and Order).
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frequency band16 to be used on an unlicensed basis for the operation of LPR equipment installed inside
closed storage tanks made of metal, concrete, or other material with similar attenuating characteristics and
also sought comment on whether to allow TLPR operation on an unlicensed basis in the 75-85 GHz
band.17 The Notice and Order also granted conditional waivers of the restriction in Section 15.205(a) that
bars intentional radiators in the 77-81 GHz restricted band to Siemens, VEGA, and any other responsible
party18 that can meet the waiver conditions specified in that decision.19 Under the terms of the waivers,
these parties could employ TLPR devices in this band if installed inside tanks with high attenuation
characteristics (e.g., metal and concrete tanks), pending the conclusion of the concurrently initiated
rulemaking.
10.
Since the adoption of the Notice and Order, the Commission received an additional
waiver request (disposed herein), as well as some inquiries, regarding outdoor use on additional
frequencies under existing Part 15 rules.20 To address the apparent need for a comprehensive and
consistent approach to LPR devices, on March 26, 2012, the Commission adopted a Further Notice of
Proposed Rule Making
(FNPRM) in this proceeding, proposing a set of common technical rules for the
operation of LPRs in any type of tanks (i.e., with low RF attenuation characteristics such as fiberglass, or
high RF attenuation characteristics such as metal) as well as in open-air environments in the following
frequency bands: 5.925-7.250 GHz, 24.05-29.00 GHz, and 75-85 GHz.21 In the FNPRM, the Commission
made new proposals that treat LPR and TLPR devices the same with respect to emission limits and
frequency bands of operation without any additional installation limitations.22 That is, a level measuring
radar that complies with our proposed rules would be able to be used in any application, whether outdoors
in the open or inside any type of enclosure.23 In adopting the FNPRM, the Commission held in abeyance

16 “Restricted” bands are frequency bands where unlicensed devices are not allowed to intentionally radiate energy
and may only emit spurious emissions. These bands are usually used by licensed services for safety-of-life
communications or for radio operations that use very low received levels, e.g., satellite downlinks or by critical and
sensitive federal services. The restricted bands are listed in 47 C.F.R. § 15.205(a).
17 Notice and Order, supra at 606-07, para. 14.
18 In this context, the “responsible party” is the party responsible for demonstrating that the communications
equipment at issue complies with the Commission’s technical requirements. Section 2.909 of the Commission’s
rules specifies the responsible party under various circumstances. 47 C.F.R. § 2.909.
19 Notice and Order, supra at 614-15, para. 41. The Commission has only granted one certification based on the
waiver terms in this Order to Siemens Milltronics Process Instruments (Siemens), FCC ID No. NJA-LR560, granted
on Dec. 23, 2010. There are no pending requests for certification under the terms of this waiver. Because the rules
we adopt here are less stringent than the waiver terms, Siemens may continue to operate its device under the waiver
for the life of the device, or submit a new application to certify the device under the new rules in Section 15.256.
20 On January 26, 2010, the Commission placed on public notice a request for waiver of Section 15.252(a) of the
Commission’s rules filed by VEGA to permit certification of LPR devices installed at fixed locations at outdoor
sites as well as inside storage tanks in the 24.6-27 GHz frequency band. See Public Notice DA 10-128, ET Docket
No. 10-27 (rel. Jan. 26, 2010). (VEGA amended this request on April 26, 2012 to ask only for certification of LPR
devices that would comply with the FNPRM proposals, pending the adoption of the LPR rules.)
21 Amendment of Part 15 of the Commission’s Rules To Establish Regulations for Tank Level Probing Radars in the
Frequency Band 77-81 GHz and Amendment of Part 15 of the Commission’s Rules To Establish Regulations for
Level Probing Radars and Tank Level Probing Radars in the Frequency Bands 5.925-7.250 GHz, 24.05-29.00 GHz
and 75-85 GHz, Further Notice of Proposed Rulemaking,
ET Docket 10-23, 27 FCC Rcd 3660 (2012) (FNPRM).
22 Id., at 3666-67, para. 15.
23 There is a growing trend towards using plastic or fiberglass tanks. FNPRM, supra at 3672, n. 65. These tank
materials provide very little RF attenuation characteristics and would be equivalent, or nearly so, to operating the
radar in open air. See Electromagnetic compatibility and Radio spectrum Matters (ERM); Short Range Devices
(SRD); Level Probing Radar (LPR) Equipment Operating in the frequency bands 6 GHz to 8,5 GHz, 24,05 GHz to
26,5 GHz, 57 GHz to 64 GHz and 75 GHz to 85 GHz; Part 1: Technical characteristics and test methods,
European
(continued….)
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all waiver requests regarding LPR operations pending final action in this rulemaking proceeding.24
11.
The FNPRM’s technical and operational proposals were based in large part on
measurements and analytical work conducted in support of the European Telecommunications Standards
Institute (ETSI) LPR Technical Standard for LPR devices.25 This standard is based on the research,
modeling and recommendations provided by the Electronic Communications Committee (ECC) within
the European Conference of Postal and Telecommunications Administrations (CEPT) in ECC Report 139,
a study of the co-existence of LPR devices with various authorized services in the 6-8.5 GHz,
24.05-26.5 GHz, 57-64 GHz, and 75-85 GHz and adjacent frequency bands.26
12.
Fourteen parties filed comments and nine parties filed replies in response to the FNPRM.
The majority of commenters support the FNPRM proposals. Some TLPR manufacturers request
variations to the proposed rules, primarily to accommodate TLPR devices inside enclosures with high RF
attenuation characteristics.27 Radio astronomy interests request a distance separation from radio
astronomy sites and a public database (or list) of LPR installations.28 Some commenters propose
additional technical restrictions on LPR devices.29 A list of commenting parties is included in
Appendix B.

III.

REPORT AND ORDER

13.
In this Report and Order, we adopt a comprehensive set of technical and operational rules
for authorizing LPR devices operating on an unlicensed basis in the 5.925-7.250 GHz, 24.05-29.00 GHz,
and 75-85 GHz in any RF level-measuring application, whether in an open-air environment or inside any
type of enclosure. New Section 15.256 will allow for the introduction of more diverse applications of
LPR in several frequency bands and improve the accuracy and reliability of these level-measuring tools
beyond what is achievable under Section 15.209. The new rules will also help to streamline equipment
development and certification of LPR devices, allowing manufacturers to take advantage of economies of
scale by marketing the same LPR device for a variety of RF level-measuring applications, as well as
provide a simplified method for measuring the radiated emissions from these devices.
14.
Our action here addresses a significant obstacle to authorizing LPR devices under our
current rules, namely, the difficulty of obtaining repeatable and accurate radiated emission measurements.
Unlike most Part 15 devices that operate with the emitter/transmitter pointing horizontally, LPR devices
must operate in a downward-pointing position such that their emissions are directed toward the substance
to be measured located below. Our current rules are designed for devices with horizontal emitters or
transmitters, and require measuring radiated emissions at a 3-meter horizontal distance from the radiating
(Continued from previous page)
Telecommunications Standards Institute (ETSI) European Norm (EN) 302 729-1 V1.1.2 (2011-05), (ETSI LPR
Technical Standard) at p. 57, Appendix G3.
24 FNPRM, supra at 3664, para. 9.
25 See Electromagnetic compatibility and Radio spectrum Matters (ERM); Short Range Devices (SRD); Level
Probing Radar (LPR) Equipment Operating in the frequency bands 6 GHz to 8,5 GHz, 24,05 GHz to 26,5 GHz,
57 GHz to 64 GHz and 75 GHz to 85 GHz; Part 1: Technical characteristics and test methods,
European
Telecommunications Standards Institute (ETSI) European Norm (EN) 302 729-1 V1.1.2 (2011-05), (ETSI LPR
Technical Standard).
26 See Impact Of Level Probing Radars Using Ultra-Wideband Technology On Radiocommunications Services,
ECC Report 139 (Feb. 2010).
27 Comments of Emerson, Krohne and Siemens.
28 Comments of NRAO and CORF.
29 Comments of Delphi, EIBASS and O3b.
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source, with the radiating source pointed directly at the measurement antenna (boresighted),30 while
varying the measurement antenna height from 1 meter to 4 meters to obtain worst-case emissions.31 This
compliance measurement practice does not yield repeatable results when LPR emissions are measured in
situ
, i.e., with the radar pointing down toward a representative substance.32 This difficulty arises because
the current measurement procedures are optimized for directly measuring device emissions,33 whereas in
situ
measurements for LPRs would essentially only measure reflected emissions, which can vary
erratically, depending on the nature of the surface at the precise moment(s) of measurement.34 To obtain
repeatable and accurate emission test results, manufacturers can measure LPR emissions directly in the
main beam of the antenna for certification compliance purposes. However, when so measured, the
general emission limit in Section 15.209 constrains LPR emissions to such a low level that the device
cannot be used for most high-precision, high-accuracy applications, such as measuring volatile liquids
inside non-corrosive fiberglass tanks or water level in rivers, for which LPR devices need higher power
than a main-beam measurement permits under our current rules to achieve the necessary precision in
these applications. The Part 15 rules that permit higher power for similar wideband devices, such as
Sections 15.250 and 15.252, contain frequency and operational restrictions which preclude the
certification of LPR devices absent a waiver, which some LPR manufacturers have sought.35
15.
Due to the normal operating condition of an LPR where it radiates in a downward
direction, potential victims of interference from LPRs are unlikely to be located in the main beam and
subject to the maximum radiated power from the device. Rather, it is the reflected emissions from
LPRs - which will be lower than the main-beam emissions - that present the greatest potential for harmful
interference.36 Because of this, and the difficulty in measuring reflected emissions discussed above, we
are amending Part 15 to add new Section 15.256 to increase the (main-beam) emissions limit for LPRs to
a level that will still ensure that the reflected emissions remain within the maximum permitted level. This
will allow LPR devices to achieve better accuracy in certain applications while not increasing the
potential of causing harmful interference to other devices. We also are requiring that all spurious or

30 Antenna boresight is the axis of maximum gain (maximum radiated power)) of a directional antenna. FNPRM,
supra at 3665, para. 11 and n. 31.
31 FNPRM, supra at 3666, para. 14.
32 47 C.F.R, § 15.31(d) requires that “[f]ield strength measurements shall be made, to the extent possible, on an open
field site.” However, the rules also allow these devices to be measured in situ, “[i]n the case of equipment for which
measurements can be performed only at the installation site,” with the device tested in its normal operating position
in an actual installation. 47 C.F.R. § 15.31(d). For LPRs, testing in situ would position the antenna pointed down
toward a representative substance, instead of pointing directly at the measurement antenna. Thus, the measurement
antenna would only capture any emission that is reflected off of the representative substance or the ground surface.
33 Measurement of direct emissions requires the antenna of the device under test be pointed directly at the
measurement antenna (boresighted). Because the LPR device is typically installed in a downward position,
measuring the LPR emissions in situ would not have the LPR device pointed directly at the measurement antenna.
34 This is because the patterns of reflected emissions tend to vary based on the irregularity of the surface of the
material below, and are therefore difficult to measure consistently, propagation losses in the higher frequency bands
are significant, and it is not always practical to create a test bed that is representative of all of the substances that an
LPR will measure, making it difficult to determine the worst-case reflectivity factor. In addition, the current
measurement procedure does not consider any potential emissions that may radiate from the top of an LPR device.
35 47 C.F.R. §§ 15.250 and 15.252. See supra para. 8.
36 All radio signals attenuate as they travel in space away from the transmitter. Free-space propagation loss is a
function of both the distance traveled and the frequency of the signal. Reflected waves are lower in amplitude than
direct waves because of the additional losses they experience (through absorption, scattering, etc.) in addition to the
distance traveled.
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unwanted emissions from LPR devices not exceed the general emission limits in Section 15.209.37
Measuring a main beam emission limit rather than measuring reflected emissions will make certification
measurements simpler, repeatable and more reliable, and allow certified LPR devices to be used either in
tanks or in open-air environments without increasing interference to any authorized services. LPRs will
have the higher power and bandwidth needed without manufacturers having to request waivers of
operational restrictions in Sections 15.250 and 15.252 for similar wideband devices as they have in the
past. To further protect authorized services operating in the same and adjacent frequency bands, we will
(1) require the LPR antenna to be dedicated or integrated as part of the transmitter and installed in a
downward position; (2) limit installations of LPR devices to fixed locations; and (3) prohibit hand-held
applications of LPR and the marketing of LPR devices to residential consumers.38 The final rules are set
forth in Appendix D.
16.
We will continue to permit certification of LPR devices under the provisions of Section
15.209 of our rules as unlicensed intentional radiators. Certification of LPRs under Section 15.209
provides an alternative for those manufacturers who may not need higher power or who want to operate in
frequency bands that are not covered by the new LPR rules. We are modifying Section 15.31 of the rules
to provide compliance testing guidance for those manufacturers who choose to certify LPR under Section
15.209.

A.

Certification under Section 15.209

17.
In the FNPRM, the Commission observed that some TLPR devices have been certified
under Section 15.209 of our rules.39 The Measurement, Control & Automation Association (MCAA)
requests that we continue to provide an option to certify LPR under the much lower general emission
limits of Section 15.209. MCAA states that because some LPR devices need to use wider bandwidth to
achieve precision measurements, it requests that LPRs be allowed to operate in any frequency range that
does not contain a restricted band as permitted by Section 15.209.40 MCAA is concerned about the 6 GHz
frequency range because the proposed LPR rules would allow operation only in the 5.925-7.250 GHz
band, whereas under Section 15.209 any unlicensed device could operate from 5.460-7.250 GHz. MCAA
also asserts that many of the metal and concrete tanks come with an existing opening for an LPR antenna,
but the opening is often too small to accommodate an antenna big enough to meet the antenna
specifications as proposed in the FNPRM.41
18.
We will continue to certify LPRs under Section 15.209. Although the new LPR rules are
intended to simplify measurement procedures and permit certification of LPR devices that could be used
both in any type of tank and outdoors in specific frequency bands, including the restricted band
75-85 GHz, we recognize that the new rules’ frequency and technical requirements may limit options for
some applications. LPR certified under Section 15.209 may operate in any non-restricted band at much
lower emission limits than permitted under the new LPR rule and, except as discussed below, would
demonstrate compliance by measuring their worst-case emissions in the main beam of the antenna; peak
emissions for pulsed LPRs may be reduced further because the rules require that peak power output use a

37 The measurement procedure for unwanted emissions would also utilize elevation and azimuth measurement scans
to determine the location at which these unwanted emissions are maximized; it is possible that the source of the
worst-case unwanted emissions from a device may be its control circuitry and/or RF leakage from its enclosure,
rather than the device's transmitter circuitry and antenna.
38 A “dedicated” antenna is an integrated antenna that is part of the main transmitter unit and cannot be replaced with
another antenna with different gain characteristics.
39 FNPRM, supra at 3674, para. 36.
40 MCAA comments at 3. This is presumably due to the fact that some LPR designs take advantage of higher power
to provide higher precision whereas some other designs take advantage of wider bandwidth to achieve such results.
41 MCAA comments at 2-3.
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pulse desensitization correction factor (PDCF).42 We observe that legacy LPR operations certified under
Section 15.209 have primarily operated in enclosed tanks with high attenuation levels and have not
caused harmful interference over the years, but manufacturers have had difficulty in demonstrating
compliance with Section 15.209 for other types of applications (e.g., open-air operation).43
19.
While TLPRs are currently receiving certification under Section 15.209 using in situ
measurement procedures,44 we will provide specific measurement guidelines for certifying LPRs that are
intended for installation inside enclosed tanks made of metal or concrete to promote consistency and
repeatability.45 Some manufacturers who have operated LPRs inside metallic and concrete tanks for
many years request that, for these uses, they continue to be permitted to demonstrate compliance with the
Section 15.209 general emission limits by measuring radiated emissions outside a representative test tank
with the LPR installed inside, as they have in the past.46 These parties point out that a tank wall made of
metal or concrete provides a substantial RF shield, and they request that LPRs intended for this type of
application not be subject to any further restriction on antenna beamwidth or main-beam emission limits,
as long as emissions measured at 3 meters outside of the tank meet the general emission limit as currently
required by Section 15.209.47
20.
We find that there is good reason for providing specific measurement procedures that
allow more flexibility for certifying, under Section 15.209, LPRs intended for installation inside
enclosures made of metal or concrete. At the same time, the rules will continue to permit manufacturers
to demonstrate compliance with the Section 15.209 general emission limits as they have in the past, by
measuring radiated emissions outside a representative enclosure with the LPR installed inside. As we
observed in the Notice and Order, TLPR emissions outside of enclosed tanks with very high RF
attenuation characteristics, e.g., steel or concrete, will likely be minimal when considering the enclosure’s
attenuation coefficient in addition to the absorption characteristics of the target material (liquid or solid),
and thus, any reflected signal will be mostly contained within the tank.48 Because metal and concrete

42 Besides the very low emission limit (i.e., -41.3 dBm EIRP), operation under the provisions of Section 15.209
requires compliance with the 20-dB peak-to-average ratio requirement and the pulse operation restrictions of Section
15.35(b) and (c), inter alia; however, it allows intentional emissions in any non-restricted frequencies, including the
5.460-7.250 GHz band. See supra n. 2.
43 We also note that those TLPR devices now operating under waiver may continue to do so provided they continue
to meet the terms of their respective waivers. See, e.g., Krohne model BM702 operating at 8.5-9.9 GHz at
http://www.krohne.com/html/dlc/MA_BM702_e_72.pdf. Krohne TLPR operation inside steel tanks in this band is
pursuant to a waiver of the 9-9.2 GHz and 9.3-9.5 GHz restricted bands of Section 15.205(a) issued in 2001 on
delegated authority by the FCC’s Office of Engineering and Technology, with concurrence of the National
Telecommunication Information Administration (NTIA).
44 In accordance with 47 C.F.R. § 2.947(a)(3), “any measurement procedure acceptable to the Commission may be
used to prepare data”.
45 The Commission’s Laboratory will establish measurement guidelines for LPR and TLPR devices following the
adoption of this Report and Order.
46 Comments of Krohne at 2, Emerson at 2 and Siemens at 2.
47 Krohne states that the RF environment around a tank with high RF attenuation characteristics is unique and
deserves to be considered separately from other LPR applications. Krohne comments at 4. Krohne does specify that
its recommendations and requests are only for metallic tanks. Krohne comments at fn. 2. Emerson states that
metallic tanks effectively shield radio frequency; therefore Emerson argues that the emission limit of Section 15.209
is easily complied with, even if the radar by itself would not pass the proposed rules for LPR. Emerson comments at
2. MCAA requests that we not specify a restriction on the antenna beamwidth for LPR intended to be installed
inside tanks made of metal or concrete that would provide enough attenuation to eliminate the effects of the
beamwidth exterior to the tank. MCAA comments at 2-3.
48 Notice and Order at 605, para. 11.
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enclosures provide substantial RF attenuation, the power in the main beam of the antenna installed within
such tanks can be increased beyond the limits required for unenclosed devices, thus permitting better
measurement performance in LPR applications49 (e.g., higher power may permit the LPR to better focus
and receive accurate echoes from the substance to be measured below the LPR), but the potential for
harmful interference is significantly diminished because the signal can be substantially attenuated by the
enclosure itself. We also note that this addresses MCAA’s concerns regarding the difficulties of
accommodating some antennas in existing openings of some metal and concrete tanks. Because other
materials do not provide the same attenuation,50 we limit these measurement procedures to LPR devices
intended to be used only in completely enclosed metal or concrete tanks.51 We are modifying Section
15.31 of the rules to provide compliance testing guidance for those manufacturers who choose to certify
LPR under Section 15.209. The final rules are found in Appendix D.

B.

New Section 15.256

1.

Frequency Bands of Operation

21.
As discussed above, most LPR devices on the U.S. market currently operate on an
unlicensed basis in frequencies around 6 GHz, 24 GHz, or 26 GHz under the general emission limits of
Section 15.209 of the Commission’s rules. These operating frequency ranges are chosen by the different
LPR manufacturers to accommodate various level-measuring applications.52 As we proposed in the
FNPRM, we will allow LPR devices certified under new technical rules we adopt herein to operate both
in any type of enclosure and in open air, in the following frequency bands: 5.925-7.250 GHz,53
24.05-29.00 GHz,54 and 75-85 GHz.55 As discussed below, the new rules address the specific spectrum

49 As an example of improved performance, the use of higher power may permit the LPR to better focus and receive
accurate echoes from the substance to be measured below the LPR.
50 ETSI found that a tank made of concrete provides approximately 35 dB attenuation around 20 GHz, whereas a
tank made of fiberglass or polyethylene (plastic) provides less than 5 dB in the same frequency range. See
Electromagnetic compatibility and Radio spectrum Matters (ERM); Short Range Devices (SRD); Level Probing
Radar (LPR) Equipment Operating in the frequency bands 6 GHz to 8,5 GHz, 24,05 GHz to 26,5 GHz, 57 GHz to
64 GHz and 75 GHz to 85 GHz; Part 1: Technical characteristics and test methods,
European Telecommunications
Standards Institute (ETSI) European Norm (EN) 302 729-1 V1.1.2 (2011-05), (ETSI LPR Technical Standard) at p.
57, Annex G. ETSI has adopted a specific standard for TLPR devices inside high-attenuation tanks. See
Electromagnetic compatibility and Radio spectrum Matters (ERM); Short Range Devices (SRD); Equipment for
Detection and Movement; Tanks Level Probing Radar (TLPR) operating in the frequency bands 5,8 GHz, 10 GHz,
25 GHz, 61 GHz and 77 GHz; Part 1: Technical characteristics and test methods,
European Telecommunications
Standards Institute (ETSI) European Norm (EN) 302 372-1 V1.2.1 (02-2011) (ETSI TLPR Technical Standard).
The FNPRM did not propose the emission levels in the ETSI TLPR Technical Standard; rather, its proposals follow
the ETSI LPR Technical Standard in order to provide one set of comprehensive requirements for all LPRs, including
TLPRs.
51 The Commission’s Office of Engineering and Technology Laboratory will publish guidance for LPR
measurements for devices designed for use inside metallic and concrete enclosures.
52 See supra para. 5.
53 The Commission currently authorizes LPR devices operating near 6 GHz under Section 15.209 in this frequency
band. See, e.g., Siemens VEGA model Sitrans LR300IQ300, FCC ID No. NJA-1Q300; Endress+Hauser model
FMR5X, FCC ID No. LCGFMR5XC.
54 The Commission currently authorizes LPR devices operating in the 24-26 GHz frequency range under Section
15.209 in this frequency band. See e.g., VEGA model VEGAPULS40, FCC ID No. MOIPULS40; Siemens model
Sitrans LR400, FCC ID No. NJA-LR400; Endress+Hauser model FMR240, FCC ID No. LCGFMR2.
55 We note that these frequencies are slightly different than those adopted by ETSI and also that in the U.S. there are
several “restricted” bands in some portions of the ETSI LPR lower frequency range. For instance, ETSI /ECC
permits LPR devices in the 6-8.5 GHz frequency range, but in the U.S., the 7.25-7.75 GHz and 8.025-8.5 GHz bands
(continued….)
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needs and restrictions in the U.S., and to the extent practicable, harmonize our technical rules for LPR
devices with similar European standards.56
a.
5.925-7.250 GHz frequency band
22.
The Commission authorizes unlicensed wideband transmitter operation within the
5.925-7.250 GHz band under Section 15.250 of its rules.57 LPR devices seeking higher power and wider
bandwidths than provided therein in order to improve their performance cannot be authorized under this
rule absent a waiver of certain usage restrictions in the rule. In this band, licensed users include
non-Federal fixed, fixed satellite, and mobile services from 5.925 GHz to 7.125 GHz; and Federal fixed
and space research services (deep space & Earth-to-space) from 7.125 GHz to 7.250 GHz.58 Part 15
transmitters operating in this band are prohibited from being used in toys or operating on board an aircraft
or satellite. They cannot utilize fixed outdoor infrastructure, including outdoor-mounted transmit
antennas, to establish a wide area communications network.59 The Commission observed in the FNPRM
that it would consider LPR operation in the 5.925-7.250 GHz band, including permitting limited fixed
outdoor installations, consistent with the intent underlying the usage restrictions in Section 15.250,
because in this regard, LPRs are single, i.e., relatively isolated, transmitters whose individual operations
outdoors would not result in the establishment of a local area network of transmitters.60
23.
Sutron, an LPR manufacturer with products intended for waterway-level measurement,
requests that the LPR rules allow operation in the 5.650-7.250 GHz band, a band slightly wider than what
was proposed in the FNPRM (i.e., 5.925-7.250 GHz). Sutron states that this wider frequency band would
provide a usable bandwidth of 1.6 gigahertz instead of 1.3 gigahertz, which would enable its products to
achieve the specific performance goals required by some of its customers. Sutron notes that the requested
additional bandwidth does not include any restricted bands listed in Section 15.205(a) of the rules.61
Krohne America Inc. (Krohne) supports Sutron but only for TLPRs inside metal tanks and suggests
(Continued from previous page)
are restricted, where the Federal Government operates critical and sensitive services such as fixed microwave, fixed
satellite, and meteorological satellite services. 47 C.F.R. § 2.106.
56 ETSI permits TLPR and LPR devices to operate in several frequency bands that we did not propose in the
FNPRM. For example, ETSI permits operation of TLPR devices inside tanks made of steel or concrete or other
material of comparable RF attenuation in the 4.5-7 GHz and 8.5-10.6 GHz bands and LPR (including TLPR)
devices in the 57-64 GHz band. See ETSI TLPR Technical Standard at p. 20; ETSI LPR Technical Standard at
p. 24. We took a different approach in the FNPRM by proposing that each authorized band be available for both
LPR and TLPR applications.
57 47 C.F.R. § 15.250.
58 47 C.F.R. § 2.106.
59 47 C.F.R. § 15.250(c). This rule prohibits fixed outdoor infrastructure to avoid the establishment of wide-area
networks of devices seeking to operate under this section. See Revision of Part 15 of the Commission’s Rules
Regarding Ultra-Wideband Transmission Systems
, Second Report and Order and Second Memorandum Opinion
and Order
, ET Docket No. 98-153, 19 FCC Rcd 24558, 24571, para. 27 (2004) (WideBand Order).
60 FNPRM, supra at 3664, n.23 and 3668, para. 20. No commenter disputes the Commission’s conclusion that LPRs
will not operate as local area networks of transmitters. While there may be multiple LPRs installed at a single site,
each device would be pointed at and computing readings from its particular target (coal or gravel piles, waterways at
a specific location, etc.) to perform the level measurement and would not be communicating with the other LPRs at
the same site. We note that EIBASS disputes as unfounded the Commission’s observation at para. 20 of the
FNPRM that it would not expect dense deployment of transmitters at an individual site (EIBASS comments at 2).
However, given the absence of networking and the manner of operation of LPR devices, there is no reason to believe
such proliferation would occur, and EIBASS provides no concrete suggestion otherwise.
61 See Sutron comments at 3.
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extending the 5925-7250 MHz band to 5460-7250 MHz band.62 MCAA in reply comments states that the
proposed bandwidth at 5925-7250 MHz is acceptable to the industry as long as Section 15.209
certification on in-tank units remains available.63
24.
We decline to expand the frequency band for LPR devices under the new rules at this
time. First, the technical and operational requirements that we are adopting under the new rules are based
on analytical work that encompasses frequencies from 6.0-8.5 GHz for LPR operations;64 therefore, we
find that compatibility of these limits with authorized services below 6 GHz has not been studied.65
Neither Sutron nor any other commenter provided technical analyses or studies to support compatibility
of LPR operating at the proposed higher emission limit with incumbent operations below 5.925 GHz.
Although Sutron argues that greater bandwidth would yield greater level measurement resolution,66
neither it nor any other party indicated with any specificity, much less demonstrated, how permitting a
higher resolution than that which can be attained under the rules we are adopting herein would further the
public interest. We conclude that, without further analyses, it would be imprudent to permit a wider
bandwidth than what we proposed in the FNPRM and to expose incumbent services unnecessarily to
additional radio noise. Further, the Commission and the NTIA are involved in active discussions relating
to the 5.850-5.925 GHz bands.67 Pending the outcome of these activities, we find that LPR devices
should be confined to the 5.925-7.250 GHz band when operating at the higher emission limit we are
adopting herein for LPR devices. Manufacturers requiring wider bandwidth than permitted under new
Section 15.256 may seek authorization, as we discussed above, by demonstrating compliance under
Section 15.209.
b.
24.05-29.0 GHz frequency band
25.
In the FNPRM, the Commission proposed to permit LPR operation in the 24.05-29.00
GHz band to provide expanded flexibility for optimizing LPR applications and to enhance global
marketing opportunities by more closely harmonizing with ETSI in this frequency range. Currently, the
Commission authorizes unlicensed wideband operation in the 23.12-29.0 GHz band under Section 15.252

62 Krohne comments at 3-5 and n. 2.
63 MCAA reply comments at 3.
64 The analysis conducted by the ECC to support the ETSI Technical Standard for LPR devices calculate main-beam
emission limits.
65 Incumbent services (fixed satellites, mobile and fixed services) between 5.925 GHz and 6 GHz in the U.S. are the
same as those above 6 GHz (up to 6.425 GHz). Incumbent services below 5.925 GHz are different than those above
5.925 GHz, and ECC’s analysis would not pertain to the protection of those services. See 47 C.F.R. § 2.106.
66 Technically, either wider bandwidth or higher power, or both, would provide higher level-measurement accuracy
and resolution, depending on the design of the LPR. Sutron’s equipment design appears to need wider bandwidth.
67 Section 6406(b)(1) of the Middle Class Tax Relief and Job Creation Act of 2012 (Tax Relief Act) requires the
Assistant Secretary of Commerce for Communications and Information (i.e., the NTIA Administrator), in
consultation with the Department of Defense (DoD) and other impacted agencies, to conduct a study evaluating
known and proposed spectrum-sharing technologies and the risk to federal users if the FCC allows Unlicensed-
National Information Infrastructure (U-NII) devices to operate in the 5.350-5.470 MHz and 5850-5.925 GHz bands.
See Pub. Law No. 112-96, § 6406(b)(1), 126 Stat. 156 at 231 (Feb. 22, 2012). NTIA published the results of its
initial study in a report (NTIA 5 GHz Report) on both these bands on January 25, 2013. 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. The Tax Relief Act also
requires the Commission to begin a proceeding to modify 47 C.F.R. Part 15 to allow unlicensed U-NII devices to
operate in the 5.35-5.47 GHz band no later than 1 year after the date of the enactment of the Act. See Revision of
Part 15 of the Commission’s Rules to Permit Unlicensed National Information Infrastructure (U-NII) Devices in the
5 GHz Band
, Notice of Proposed Rule Making, ET Docket No. 13-49, 28 FCC Rcd 8864 (2013).
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of its rules.68 LPR devices seeking higher power and wider bandwidths to improve their performance
cannot be authorized under this rule absent a waiver of certain usage restrictions in the rule. While some
LPRs currently operate in this band, their utility is limited by the restrictions of Section 15.252. This
band is shared between Federal and non-Federal services. Authorized licensed operations include
radiolocation, Earth exploration satellite service (EESS) (active), amateur, fixed, inter-satellite,
radionavigation, radiolocation satellite (Earth-to-space), fixed satellite (Earth-to-space), mobile, standard
frequency and time signal satellite (Earth-to-space), space research (space-to-Earth), and EESS
(space-to-Earth) services. Unlicensed transmitters operating in the 23.12-29.0 GHz band subject to this
rule must be mounted on vehicles and cannot be used in aviation applications.69 Finally, in the FNPRM,
the Commission observed that the proposed frequency band is wider than that which ETSI has adopted; 70
however, it believed that the risk of interference to incumbent authorized services from LPR devices will
be no greater than it is from Part 15 vehicular radars currently operating in this band because LPR devices
operate in a fixed downward-looking position, and because there have been no interference complaints
related to the operation of these Part 15 radars, which unlike LPRs do not always operate in a downward
position.71 There were no comments related to our proposals in this band, and for the reasons stated
above, we will allow LPRs to operate within the 24.05-29 GHz frequency band at the radiated emission
limits under new Section 15.256.
c.
75-85 GHz frequency band
26.
Apart from a handful of specified frequency bands, spectrum above 38.6 GHz, including
most of the 75-85 GHz band,72 is designated as “restricted” in Section 15.205 of the rules.73 Unless
expressly permitted by rule or waiver, unlicensed devices are not allowed to intentionally radiate energy
into a restricted band, in order to protect sensitive radio services from harmful interference.74 The
Commission has permitted unlicensed operation within specific frequency bands above 38.6 GHz, i.e.,
46.7-46.9 GHz, 57-64 GHz, 76-77 GHz, and 92-95 GHz.75
27.
The 75-85 GHz band is shared between Federal and non-Federal services. Authorized
operations in this band currently include radio astronomy, fixed/mobile/fixed satellite, mobile satellite,
broadcast and broadcast satellite, radiolocation, space research (space-to-Earth), amateur and amateur
satellite services.76 In addition, unlicensed vehicular radars are currently permitted to operate in the
76-77 GHz band.77 In the FNPRM, the Commission observed that the services in this band typically

68 47 C.F.R. § 15.252.
69 Unlicensed devices authorized in this band under the general limits of 47 C.F.R. § 15.209 are not subject to these
restrictions, except that they may not operate at all in the 23.6-24.0 GHz restricted band (see 47 C.F.R. § 15.205).
70 The ETSI LPR standard specifies LPR operation in the 24.05-26.5 GHz band.
71 FNPRM, supra at 3668, para. 21.
72 The Commission opened the 76-77 GHz band to unlicensed vehicular radars in 1995 in Amendment of Parts 2, 15
and 97 of the Commission’s Rules to Permit Use of Radio Frequencies Above 40 GHz for New Radio Applications,
First Report and Order and Second Notice of Proposed Rule Making,
ET Docket 94-124, 11 FCC Rcd 4481 (1996).
73 47 C.F.R. § 15.205(a).
74 See Revision of the Rules Regarding Operation of Radio Frequency Devices Without an Individual License, First
Report and Order,
GEN Docket 87-389, 4 FCC Rcd 3493 (1989). See also 47 C.F.R. § 15.205(a).
75 See 47 C.F.R. §§ 15.253, 15.255 and 15.257. The 57-64 GHz band is open to most types of unlicensed
operations, while the 46.7-46.9 GHz and 76-77 GHz bands are limited to unlicensed vehicular radars, and operation
within the 92-95 GHz band is limited to indoor applications.
76 47 C.F.R. § 2.106.
77 47 C.F.R. § 15.253.
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employ highly directional antennas to overcome the relatively higher propagation loss that occurs at these
frequencies.78 The Commission stated its belief that LPR operation in the 75-85 GHz band would not
adversely affect incumbent authorized users, because this band is currently sparsely used and the
propagation losses are significant at these frequencies, making harmful interference unlikely beyond a
short distance from the LPR device.79
28.
CORF notes that RAS has primary allocations at 76-77.5 GHz and 78-85 GHz and does
not oppose sharing these bands with LPRs provided the Commission adopts certain protections designed
to ensure that RAS can operate in the interference-free environment that the service requires for picking
up extremely weak signals.80
29.
Delphi Automotive (Delphi) reminds us that the European Union (EU) has authorized the
entire 77-81 GHz band for short-range vehicle radar applications and urges us to take automotive radar
into account when considering TLPR/LPR operations in this band.81 We observe that the Commission
has authorized vehicular radar operation, including Foreign Object Debris (FOD) detection fixed radar
operations at airports, in the 76-77 GHz band under its Part 15 unlicensed rules; 82 and a rulemaking
petition is now pending asking that we permit unlicensed vehicular radars to operate in the 77-81 GHz
band as well.83 We further note that the Commission has modified Section 90.103 of the rules to permit
the certification, licensing and use of FOD detection radars in the 78-81 GHz band.84 We find that FOD
radars and LPR devices would most likely not operate in the same geographical location, because the
FOD radars are only authorized to operate at airports whereas LPR typically operate in industrial or
remote areas. However, as discussed above, even if they were co-located, at these frequencies, the
potential for harmful interference to FOD radars from LPR is extremely unlikely, given the substantial
free-space propagation losses and the extremely narrow beamwidths of the FOD radar.85 As for spectrum
sharing between vehicular radars and LPR, we believe that LPR devices will be able to co-exist
successfully with vehicular radars because the LPR is installed in a downward-looking position at fixed
locations and the main-beam emission limits have been carefully calculated to avoid harmful interference
to other radio services. We further find that the extreme propagation losses of radio signals at these

78 FNPRM, supra at 3669, para. 23. There is approximately 58 dB of free space attenuation at 3 meters for a 6 GHz
signal and 80 dB of free space attenuation at 3 meters for an 80 GHz signal. Free space path loss (FSPL) is
calculated according to the formula FSPL = 20 log F(GHz) + 20 log D(m) + 32.5, with frequency F in GHz and
distance D in meters. FNPRM, supra at 3669, n.51.
79 See FNPRM, supra at 3669, para. 23 and n.55 (observing that the wavelength of an LPR device operating at
75 GHz is 4 millimeters, and the free space path loss at this frequency is approximately 79.5 dB at a distance of
3 meters (i.e., 750 wavelengths away) from the transmitter).
80 CORF comments at 1-3.
81 Delphi comments at 3.
82 See Amendment of Sections 15.35 and 15.253 of the Commission’s Rules Regarding Operation of Radar Systems
in the 76-77 GHz Band, and Amendment of Section 15.253 of the Commission’s Rules to Permit Fixed Use of Radar
in the 76-77 GHz Band,
ET Docket Nos. 11-90 and 10-28, Report and Order, 27 FCC Rcd 7880 (2012).
83 See Petition for Rulemaking filed by Robert Bosch, LLC. Filed on April 16, 2012 in Amendment of Part 15 of the
Commission’s Rules to Permit the Operation of Vehicular Radar Systems in the 77-81 GHz
, RM-11666,
DA 12-1139.
84 Amendment of the Commission’s Rules to Permit Radiolocation Operations in the 78-81 GHz Band, and Request
by the Trex Enterprises Corporation for Waiver of Section 90.103(b) of the Commission’s Rules
, WT Docket No.
11-202, Report and Order, 28 FCC Rcd 10423 (2013) (Part 90 FOD Order).
85 A FOD radar operating in the 78-81 GHz band under Part 90 of the rules typically has a 1 degree (elevation) x 0.4
degree (azimuth) antenna beamwidth. See Part 90 FOD Order at para. 11, n. 37.
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frequencies would mitigate any potential harmful interference beyond a very short distance from the LPR
device, as noted above.
30.
Accordingly, we will allow LPR to operate within the 75-85 GHz frequency band, at the
radiated emission limits specified in new Section 15.256 discussed below. To permit LPR operation in
the 75-85 GHz band, we also modify Section 15.205 of the rules to remove the prohibition on intentional
emissions in this band for LPR devices authorized under the new rules.86
2.

Technical Requirements

31.
To maintain the existing interference protection criteria to authorized services in the
frequency bands covered by new Section 15.256 for LPR operations, the FNPRM invited comment on
establishing requirements for the following interdependent parameters: main-beam radiated emission
limits,87 antenna beamwidth,88 and antenna side-lobe gain.89 Main-beam emissions must be measured
with the LPR antennas “boresighted” to produce the maximum realizable antenna coupling.90 The
main-beam emission limits we adopt will allow an LPR device to operate at higher peak levels than
Part 15 currently permits91 but would continue to provide the same level of interference protection to
authorized services as any other Part 15 device operating under the general emission limits,92 provided
that the LPR antenna always maintains a downward position and utilizes a relatively narrow beamwidth.93
Because the LPR is always pointing downward and direct emissions from the LPR antenna are focused by
a narrow beamwidth toward the substance being measured, it is unlikely that emissions reflected from this
material or from the ground surface would cause interference to a potential victim receiver located at any
height relative to the LPR due to the significant attenuation of the reflected signal.
32.
The technical and operational requirements proposed in the FNPRM and discussed below
are based on analytical work performed by the ECC in support of the ETSI Technical Standard for LPR
devices.94 This standard specifies compliance measurements based on main-beam emission limits. To

86 47 C.F.R. § 15.205.
87 FNPRM, supra at 3669-72, paras. 24-28.
88 Id. at 3672, para. 29.
89 Id. at 3672, para. 30.
90 Antenna boresight is the axis of maximum gain (maximum radiated power) of a directional antenna. The LPR
transmitter antenna would be pointed directly at the measurement antenna, which would receive and measure the
maximum radiated power.
91 Sections 15.209 and 15.35(b) impose a total peak limit of -21.3 dBm for operation of Part 15 devices above
960 MHz. 47 C.F.R. §§ 15.209 and 15.35(b). Sections 15.250 and 15.252 impose a peak limit of 0 dBm in a
50-megahertz bandwidth for Part 15 devices operating in the 5.925-7.250 GHz, 16.2-17.7 GHz and
23.12-29.00 GHz frequency bands. 47 C.F.R. §§ 15.250 and 15.252. The ECC LPR peak emission limits are
+7 dBm for LPR devices operating in the 5.925-7.250 GHz band, +26 dBm for LPR devices operating in the
24.05-29.00 GHz band and +34 dBm for LPR devices operating in the 75-85 GHz band, as measured in a
50-megahertz resolution bandwidth. The limits differ for each frequency band because the modeling took into
account the frequency-dependent propagation loss characteristics in each band.
92 The Part 15 rules specify an average emission limit of -41.3 dBm from Part 15 devices operating above 960 MHz,
as the minimum protection to authorized services. The ECC modeling provides for an equivalent main-beam
average emission limit of -33 dBm in the 5.925-7.250 GHz band, -14 dBm for LPR devices operating in the
24.05-29.00 GHz band, and -3 dBm for LPR devices operating in the 75-85 GHz band, as measured in a
1-megahertz resolution bandwidth. The limits again differ for each frequency band because the modeling took into
account the frequency-dependent propagation loss characteristics in each band.
93 “Beamwidth” refers to the angle between the half-power points (i.e., the -3 dB points) of the main lobe of an
antenna, when referenced to the maximum power of the main lobe. Beamwidth is usually expressed in degrees.
94 See supra para. 11; FNPRM, supra at 3667, para. 16.
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determine the maximum allowable radiated emission limits for LPR devices operating in each authorized
frequency band, the ECC studied the interference potential of an LPR by taking into account reflected
emissions within a hemispherical boundary around the LPR device. The ECC assumed a worst-case
material reflectivity coefficient and determined the main-beam emission level that correlates to the
appropriate reflected emission level. We find that the analytical work of ETSI/ECC provides a reliable
correlation between main-beam emissions and emissions at 3 meters from the LPR that is sufficiently
conservative to conclude that the use of a main-beam emission limit rather than limits based on reflected
emissions will not create a greater interference potential, thus providing strong support for the approach
we are taking here. Moreover, a main-beam emission limit would represent a more realistic evaluation of
interference potential and permit higher power, thus increasing the accuracy and utility of LPRs. At the
same time, it will simplify compliance measurements of LPR emissions, because emissions from the LPR
would be measured directly in the main beam of the antenna where maximum emissions are found, thus
avoiding the measurement of reflected emissions that can be highly variable due to the variable
site-related factors involved with in situ testing.95 Under this approach, certification measurements will
be simpler, repeatable and more reliable. Accordingly, we amend the rules to require that LPR radiated
emissions be measured in the main beam of the LPR antenna.96 We note that no party opposes the use of
main-beam emission measurement or the general measurement principles in the FNPRM proposed rules.97
a.

Radiated Emission Limits

33.
In the FNPRM, the Commission proposed radiated emission limits that are listed in
Table 1 below.98 These limits are based on the results of the ECC’s mathematical modeling and
supported by measurement data,99 which show that if the LPR complies with the main-beam (boresight)
emission limits specified in the second and third columns of Table 1, all emissions, including antenna
back-lobe and side-lobe emissions and worst-case reflections from the target material, will also comply
with the existing average emission limit specified in Section 15.209 for devices operating above
960 MHz, shown in the table’s fourth column.100 The main-beam emission limits vary with frequency
bands because the mathematical model accounts for the frequency-dependent propagation loss

95 ECC Report 139 at p. 2 and p. 11.
96 The Commission’s Office of Engineering and Technology (OET) will publish guidance for LPR measurements
for devices designed to operate under new Section 15.256.
97 With respect to the measurement principles proposed in the FNPRM, we are clarifying step (6) of proposed
Section 15.256(j) in the FNPRM as follows: “…(6) compliance measurements for minimum emission bandwidth of
frequency-agile LPR devices shall be performed with any related frequency sweep, step, or hop function activated.”
This provision is intended to apply only to minimum bandwidth measurements, and not to other measurements such
as power level measurements, as originally requested by the LPR industry (see MCAA Notes on Rulemaking filed
Jan 31 2011). This provision is necessary for minimum emission bandwidth measurements because it is very
difficult to get accurate emission bandwidth measurements if the frequencies are not properly activated while doing
such measurements. The clarified provision is found in Appendix B, Section 15.256(l)(6).
98 FNPRM, supra at 3670, para. 24.
99 ECC Report 139 at Annex 4.
100 FNPRM, supra at 3670, para. 24. We note that the ETSI equivalent average reflected emission level in the
5.925-7.250 GHz band (used to derive the average and peak main-beam limits) – which we are adopting here for
those who seek certification of LPR devices under the provisions of new Section 15.256 – is more stringent than
the -41.3 dBm EIRP limit that applies to certification under Section 15.209; for Section 15.256 certifications, we
nevertheless employ the stricter limit to harmonize with Europe on the derived main-beam limits for this frequency
range. We note also that in our rules, the limits at these frequencies for some UWB devices are also more stringent
than Section 15.209. See e.g., 47 C.F.R. §§ 15.510(c)(4) and 15.515(d).
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characteristics associated with each band.101 The Commission stated that because the emission limits for
main-beam emissions were derived by mathematically correlating the reflected emissions from an LPR
with the existing Part 15 average emission limit for devices operating above 960 MHz, it expected that the
LPR main-beam emission limits would maintain the existing level of interference protection to incumbent
radio services.102 The Commission further noted that harmonization of its emission limits with the ETSI
limits is desirable because it could serve to expand global marketing opportunities for U.S.
manufacturers.103

Table 1 – LPR Emission Limits

Frequency
Average Emission
Peak Emission Limit
Equivalent Average
Band
Limit (EIRP in
(EIRP in dBm
Reflected Emissions if
(GHz)
dBm/MHz) as
measured in 50 MHz)
measured in situ (EIRP
measured boresight
as measured boresight
in dBm/MHz) (Note 3)
(main beam) (Note 2)
(main beam) (Note 2)
5.925-7.250
-33
+7
-55
24.05-29.00
-14
+26
-41.3
75-85
-3
+34
-41.3

Notes:

1. Minimum bandwidth at the -10 dB points is 50 megahertz.
2All emission limits defined herein are based on boresight measurements (i.e., measurements
performed within the main beam of an LPR antenna).
3. Equivalent reflected emissions include antenna back-lobe and side-lobe emissions and
worst-case reflections from material being measured.
34.
We are adopting distinct radiated emission limits for LPR devices operating in each of
the frequency bands, as set forth in Table 1 above. As discussed above, the emission limits for
main-beam emissions were derived by mathematically correlating the reflected emissions from an LPR
with the existing Part 15 average emission limit at -41.3 dBm EIRP for devices operating above 960 MHz
–or lower levels (at -55 dBm EIRP for frequencies below 8.5 GHz).104 The LPR main-beam emission
limits therefore would maintain the existing level of interference protection to incumbent radio services.

101 Higher frequencies have more associated propagation losses. For example, there are approximately 58 dB of free
space path loss at 3 meters for a 6 GHz signal versus 80 dB for an 80 GHz signal.
102 ETSI/ECC calculated through mathematical modeling the amount of main-beam emissions of a
downward-pointing antenna that would limit reflected emissions to 500V/m at a distance of 3 meters from the
source, which is equivalent to an EIRP level of -41.3 dBm (this is the same as the Part 15 existing average emission
limit.) Its mathematical modeling took into account reflected emissions in the vertical plane above the LPR device–
as in the case of an open-air LPR installation over water–as well as reflected emissions in the horizontal plane
around the LPR device with a worst-case scenario of material reflectivity coefficient. ETSI/ECC determined that
because the LPR is always pointing downward, only reflected emissions would be seen by a potential victim
receiver of an authorized radio service located overhead (e.g., a satellite receiver) or horizontally relative to the LPR
transmitting source.
103 FNPRM, supra at 3670, para. 24.
104 In order to derive the main-beam emission limit for each of the LPR operating frequency bands, ECC modeling
uses -41.3 dBm EIRP (the same level as the general emission limit in Section 15.209 of the Commission’s rules) as
equivalent reflected emission levels for frequencies higher than 8.5 GHz. For frequencies below 8.5 GHz, ECC
modeling uses the lower value of -55 dBm EIRP to account for lesser propagation losses and different incumbent
services.
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As the Commission tentatively concluded in the FNPRM, the LPR emission limits for each of the
specified operating frequency bands as measured in the main beam of the LPR antenna will adequately
protect against harmful interference to incumbent authorized services in any of the proposed frequency
bands, based on several factors.105 First, LPR devices will be required to utilize downward-focused
narrow-beam transmit antennas, which are also needed to optimize level-measuring performance;
therefore, the only LPR emissions likely to be incident on an incumbent receiver within proximity will be
reflected from the target material and thus significantly attenuated. Second, the LPR emission limits are
consistent with the results expected from application of the existing limits in radiated in situ
measurements and therefore will maintain the existing level of protection afforded to incumbent
authorized services under existing rules and their attendant measurement procedures.106 Third, as the
operating frequency increases, the propagation path loss also increases as a result of the increased
attenuating effects on radio waves from intervening objects and atmospheric conditions, and we account
for this by varying the permitted radiated emission limit for each frequency band. None of the
commenters took issue with any of these factors or with the conclusion that the proposed limits will
provide adequate protection against harmful interference. Moreover, our adoption of several operational
restrictions, discussed below, in addition to these emission limits, provides further assurance that
authorized services will not be subject to harmful interference.
35.
The Engineers for the Integrity of Broadcast Auxiliary Services Spectrum (EIBASS)
argue that, for LPRs operating in the 6 GHz frequency range, an increase from the existing peak EIRP
of -21.3 dBm allowed in Sections 15.209 and 15.35(b)107 to the proposed +7 dBm would be a potential
co-channel interference threat to TV Broadcast Auxiliary Service (BAS) service in the 6.425-6.525 GHz
and 6.875-7.125 GHz frequency bands.108 EIBASS contends that, while the 6.425-6.525 GHz TV BAS
operations are mobile only, the primary use of the 6.875-7.125 GHz TV BAS band is for fixed,
point-to-point links, including studio-to-transmitters link (STL) paths that demand the highest level of
interference protection.109 EIBASS is also concerned about allowing LPRs to operate outdoors in these
bands despite the restriction against “fixed outdoor infrastructure” for 6 GHz wideband devices operating
under Section 15.250(c).110 EIBASS states that there is no basis for the Commission to assume that only
one high-power outdoor LPR device would be employed at a particular site.111 In reply, MCAA argues
that TV BAS STL links are installed high off the ground and use highly directional receive antennas,
making received interference from LPRs highly unlikely. It further contends that no 6 GHz authorized
users – including those operating TV BAS STLs -- have received interference from Part 15 devices
operating under Section 15.250 and using the same general modulation techniques as LPR devices.112
36.
We agree with MCAA that because STL links are installed high off the ground with
highly directional receive antennas, received interference from LPRs that point downward toward the
measured substance is highly unlikely. We do not believe that EIBASS is correct in comparing LPR

105 FNPRM, supra at 3671, para. 26.
106 See 47 C.F.R. §§ 15.250(d)(1), 15.252(b)(1) & (2), 15.509(d), 15.510(d)(3), 15.511(c), 15.513(d), 15.515(d),
15.517(c), and 15.519(c).
107 47 C.F.R. §§ 15.209 and 15.35(b).
108 EIBASS comments at para. 1.
109 Id.
110 Id., at para. 3. Section 47 C.F.R. § 15.250(c) prohibits fixed outdoor infrastructure to avoid the establishment of
wide-area networks of devices seeking to operate under this section. See Wide-Band Order, 19 FCC Rcd 24558,
24571, para 27 (2004).
111 Id.
112 MCAA reply comments at 8.
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devices to other unlicensed narrowband Part 15 devices that operate under Sections 15.209 and 15.35(b)
of our rules because LPR devices are wideband devices that are more similar to unlicensed devices
operating under Section 15.250 of the rules.113 While it is true that the proposed main-beam peak
emission limit for LPR is 7 dB higher than the peak emission limit in Section 15.250, i.e., 0 dBm peak
EIRP,114 with the LPR antenna pointing down toward the substance being measured, only reflected
emissions (which typically are already attenuated from the direct emission levels) would be expected.115
Because of reflection losses, LPR emission levels are therefore lower than other unlicensed wideband
devices operating in the same frequency range. Further, because STL antennas are also directional in
nature, there are additional antenna losses in the potential STL victim receive antenna, unless the LPR
emissions are in the STL antenna main beam, which is a highly unlikely circumstance. We further note
that the number used to derive the LPR equivalent main-beam emission limit at 6 GHz is actually 14 dB
lower (at -55 dBm EIRP) than the average emission limit in Section 15.250 (at -41.3 dBm EIRP)116 for
Part 15 devices operating in the same bands as STLs.117 Therefore, in the 6 GHz frequency range, the
proposed main-beam emission limit is constraining any potential reflected emissions from an LPR to a
level lower than the existing interference protection level for authorized services from unlicensed devices,
resulting in a 14 dB additional interference protection margin for authorized services as compared to that
provided by other Part 15 devices. Furthermore, as MCAA observes, there has not been any case of
harmful interference to STL links from other Part 15 devices that currently operate in the same frequency
band (devices that do not even have the interference-avoiding characteristic of being pointed
downward).118 We further note that LPR devices are not by their nature used to establish local or wide
area networks119 because LPRs are designed to measure the level of a substance at a single, circumscribed

113 47 C.F.R. § 15.250. This section covers unlicensed wideband devices operating within the 5.925-7.250 GHz
band with operating bandwidths at least 50 MHz. LPR devices typically have bandwidths exceeding 50 MHz. The
Commission has recognized that the peak emission limit specified in 47 C.F.R. § 15.35(b) was established based on
the operation of narrowband transmission systems and may unfairly penalize some wideband operations, effectively
prohibiting the operation of these devices, and has stated that this existing limit on the total peak power level is not
well suited to measure the operation of, or represent the interference potential of, transmitters that employ extremely
wide bandwidths. See Revision of Part 15 of the Commission’s Rules Regarding Ultra-Wideband Transmission
Systems, Second Report and Order and Second Memorandum Opinion and Order,
ET Docket No. 98-153, 19 FCC
Rcd 24566, 24558, para. 17 (2004) (UWB Second Order and Second MO&O).
114 47 C.F.R. § 15.250(d)(3).
115 Due to the operating nature of LPR devices, their emissions sustain several losses before they can reach a
potential victim receiver. An LPR antenna is typically mounted at least 3 meters above the material it is intended to
measure, pointing down toward that material. Free-space path loss (FSPL) from the LPR antenna to the measured
material in the 5.925-7.250 GHz band is approximately 58 dB. Worst-case reflection losses calculated by
ETSI/ECC studies add another 22 dB. Therefore, peak reflected emissions that could reach a potential STL victim
receiver in this receiver’s antenna main beam would be attenuated by 80 dB, from the proposed +7dBm peak EIRP
to -73 dBm peak EIRP.
116 The -41.3 dBm EIRP average emission limit in Section 15.250 is the same as the general emission limit in
Section 15.209. 47 C.F.R. §§ 15.250 and 15.209. This limit is generally used as interference protection criteria for
authorized radio services from unlicensed operations.
117 See Table 1, fourth column, above. ETSI/ECC calculations for LPR main-beam emission limits in the 6 GHz
frequency range are based on maintaining a -55 dBm EIRP reflected emission level within a 3-meter hemispheral
boundary around the LPR antenna. See Impact Of Level Probing Radars Using Ultra-Wideband Technology On
Radiocommunications Services
, ECC Report 139, at 19-20 (Feb. 2010).
118 See, e.g., Zebra Technologies Corporation Model UWT1100, FCC Identifier XWX-UWT1100; TDC Acquisition
Holdings, Inc. Model PLUS-0309, FCC Identifier NUF-PLUS-0309; Ubisense Ltd. Model UbiTagV2.3, FCC
Identifier SEAMOD23.
119 The basis of the prohibition of outdoor fixed structure in Section 15.250(c) is to prevent devices operating in the
5.925-7.250 GHz band to establish wide-area networks. 47 C.F.R. § 15.250(c).
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site (e.g., a pile of coal or gravel, or water in a tank or under a bridge).
37.
Aggregate emissions of LPR devices. CORF notes that there are important Earth
Exploration-Satellite Service (EESS) passive observations made in the primary allocated bands at 22.21-
22.5 GHz and 23.6-24.0 GHz, and urges us to consider aggregate emission limits for LPRs to avoid the
impact of interference from multiple LPR devices on EESS activities in these bands.120 O3b Limited
(O3b) is also concerned about potential interference to its non-geosynchronous orbit (non-GSO) satellites
operating in the 26 GHz band from aggregate operation of LPRs raising the noise floor. O3b requests that
we require LPR to adhere to Section 15.5 non-interference rules.121
38.
We observe that in calculating the LPR main-beam emission limits, the ECC Report 139
did take into account the co-existence between LPRs and EESS operating in the EESS allocated
frequencies. ECC simulations show that in the most critical scenarios, there are wide margins of safety
against harmful interference to EESS, even when using a very conservative number for the possible future
growth of LPR devices in the long-term. CORF did not dispute these ECC analyses.122 We therefore find
that there would be minimal or no effect on EESS or non-GSO satellite services from LPRs operating in
the 24-26 GHz frequency range, and thus we do not adopt aggregate emission limits for LPR in these
bands. We also observe that LPR, as all unlicensed devices operating under Part 15 of the Commission
rules, are subject to the non-interference rules in Section 15.5.
39.
Unwanted (harmonic and spurious) emissions of LPR devices. In the FNPRM, the
Commission proposed that LPR unwanted emissions for LPRs operating in any of the specified operating
frequency bands be suppressed to below -41.3 dBm EIRP.123 Hach, a manufacturer for LPRs operating in
the 26 GHz frequency range, states that establishing a limit for harmonic emissions at an average power
spectral density of 20 dB below the fundamental emissions would bring our rules in line with ETSI and
help manufacturers take advantage of economies of scale.124 In reply, MCAA contends that a 20-dB
difference between harmonic and fundamental emission limits would relax the limits for LPRs operating
in the 26-GHz band, such as the Hach equipment, as well as for LPRs operating in the 80-GHz range, but
would subject those LPRs operating in the 6-GHz frequency range to more stringent standards.125
Although MCAA states that it does not oppose the Hach proposal, it asserts that the proposal needs
further study.126
40.
We note that similar Part 15 equipment operating under Section 15.250 in the
5.925-7.250 GHz band and under Section 15.252 in the 23.12-29 GHz band are subject to unwanted

120 CORF comments at 4.
121 O3b reply comments at 2. See also 47 C.F.R. § 15.5. Under these rules, all unlicensed devices operating under
Part 15 are subject to the condition that they not cause harmful interference and that they cease operation if they do
cause such interference.
122 ECC Report 139, at 35-38. ECC noted that although the data from ETSI Technical Report 102 601 regarding
LPR market growth up to 2015 indicate a maximum expected LPR density per km2 of 0.00238, ECC decided to use
a very conservative figure of 0.005 in calculating the interference scenario for worst-case vertical LPR emissions in
ECC Report 139, and a good interference safety margin was still found.
123 FNPRM, supra at 3667, para.16. This means that for LPRs operating in the 26 GHz range at the maximum
average emission limit of -14 dBm EIRP must suppress their unwanted emissions by 27.3 dB.
124 Hach comments at 8; Hach reply comments at 2.
125 MCAA reply comments at 3-4. Using a 20-dB difference, the unwanted emission limit would be -53 dBm EIRP
for LPRs operating in the 6 GHz range, -34 dBm EIRP for LPRs operating in the 26 GHz range, and -23 dBm EIRP
for LPRs operating in the 80 GHz range. The Commission has proposed to limit all LPR unwanted emissions to less
than -41.3 dBm EIRP, the same as the general emission limit in Section 15.209 of the rules. 47 C.F.R. § 15.209.
126 MCAA reply comments at 4.
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emission limits that are much more stringent than what we proposed for LPR devices,127 because we
expect that LPRs will have a low interference potential as they operate in a fixed downward position.
However, we do not believe that LPR unwanted emissions should be allowed to be as high as -34 dBm
EIRP as Hach requests for LPRs operating in the 26 GHz frequency range, because as we discussed above
our goal is to maintain the existing interference protection criteria (i.e., the Part 15 general limit of less
than -41.3 dBm EIRP) to authorized services from LPR’ unwanted emissions.128 Further, the same
principle of establishing an unwanted emissions limit at 20 dB below the fundamental limit would allow
unwanted emissions from LPRs operating in the 80 GHz range to be as high as -23 dBm EIRP.129 We
find that the -41.3 dBm EIRP general emission limit of Section 15.209 is appropriate so as to constrain
any LPR unwanted emissions to the existing level of interference protection for incumbent users of the
spectrum and Hach has not presented evidence that this is an inappropriately strict level for Part 15
devices in general or for LPRs in particular. We therefore deny Hach’s request for LPR unwanted
emissions to be 20 dB below the fundamental emissions.
a.

Antenna Requirements

41.
An antenna converts electrical signals traveling along a transmission line into
electromagnetic energy that is radiated into the environment. Antennas such as those used in LPR
devices are directional, in that the energy being transmitted is concentrated into one direction. If the gain
characteristics of the antenna are plotted, a pattern is formed that consists of a single main lobe in the
direction in which the majority of the energy is transmitted. In addition to the main lobe, there are
multiple side lobes in undesired directions. The magnitude of the main lobe is called the gain of the
antenna, and is compared to the magnitude of an isotropic antenna that transmits energy equally in every
direction. Because an antenna can only focus energy, but cannot create additional energy, a higher gain
(more energy) in the main lobe of the antenna can be realized only when the beamwidth of the main lobe
is narrowed, accordingly reducing the gain in the side lobes (lessening the energy in other directions). In
other words, the beamwidth, main-beam gain, and side-lobe gain of the antenna are all interdependent.
Since we are specifying a maximum antenna beamwidth, for any given antenna, there is necessarily a
minimum antenna gain that corresponds to the maximum beamwidth and a corresponding maximum
side-lobe gain as well.
(i)

Antenna Beamwidth

42.
In the FNPRM, the Commission proposed an antenna beamwidth no greater than
12 degrees for frequencies below 57 GHz and no greater than 8 degrees in the 75-85 GHz bands.130
Because the main source of the scattering of LPR emissions is the interaction with the surface being
measured, the proposed maximum antenna beamwidth for LPRs was restricted to limit emission

127 See 47 C.F.R. §§ 15.250(d)(1) and Section 15.252(b)(2). For example, Part 15 devices operating in the
5.925-7.250 GHz band under Section 15.250 must suppress unwanted emissions to less than the following EIRP
levels: -75.3 dBm in the 960-1610 MHz band, -63.3 dBm in the 1610-1990 MHz band, -61.3 dBm in the
1990-3100 MHz band, - 51.3 dBm in the 3100-5925 MHz band, -51.3 dBm in the 7250-10600 MHz band,
and -61.3 dBm above 10600 MHz. All of these levels are at least 10 dB more stringent than what we are proposing
for LPR unwanted emissions.
128 For LPRs operating in the 24.05-29 GHz band, the fundamental emission limit proposed in the FNPRM and
adopted herein is -14 dBm EIRP. Thus, with Hach’s proposal for a 20-dB difference, the unwanted emissions would
only be suppressed to less than -34 dBm EIRP, which is higher than the Part 15 interference criteria
of -41.3 dBm EIRP.
129 For LPRs operating in the 75-85 GHz band, the fundamental emission limit proposed in the FNPRM and adopted
herein is -3 dBm EIRP. Thus, with Hach’s proposal for a 20-dB difference, the unwanted emissions would only be
suppressed to less than -23 dBm EIRP, which is higher than the Part 15 interference protection criteria
of -41.3 dBm EIRP.
130 FNPRM, supra at 3672, para. 29; ECC Report 139 at p. 3.
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scattering in order to control the interference potential of LPRs to other radio services.131 The
Commission also observed that maintaining a narrow antenna beamwidth could enhance LPR
performance because a narrower beam reduces false echoes from objects other than the desired target
material.132
43.
In its comments, Sutron requests that the proposed antenna beamwidth of 12 degrees be
changed to permit an antenna beamwidth of 35 degrees, which is 23 degrees wider.133 Sutron states that
because a narrower beamwidth would result in a physically larger antenna, the size of a 6 GHz antenna
with a 12 degrees beamwidth would be 10x12 inches for the aperture opening and a length of 28 inches.
It contends that such an antenna in an open outdoor environment will increase the cost to support the
antenna structure in windy conditions or under heavy snow loading. Sutron states that it has performed
an actual antenna test to show that the horizontal emissions of its LPR device are less than the equivalent
proposed horizontal emission level for LPRs operating in this frequency band134 and argues that the
horizontal emissions it measured are too low to constitute a threat to spectrum incumbents.135
44.
We are adopting our proposed antenna beamwidth limitations of no greater than
12 degrees for frequencies below 57 GHz and no greater than 8 degrees in the 75-85 GHz bands. First,
the antenna beamwidth limits proposed in the FNPRM were designed to be consistent with the proposed
main-beam emission limits, which in turn were based on ETSI standards.136 As noted above,
harmonization of our emission limits with the ETSI limits serves to expand global marketing
opportunities for U.S. manufacturers. We conclude that any benefits that might result from Sutron’s
proposed beamwidth limits would be outweighed by the potential benefits of harmonization with
European standards. Moreover, we note that a wider main beam could result in greater reflected
emissions, and increase the potential for harmful interference to other spectrum users. We further observe
that other waterways level-measuring LPR manufacturers such as Hach state in their comments that their
devices use planar antennas which have outer dimensions much smaller than a horn antenna, are less
obtrusive and less susceptible to vandalism and can still meet the proposed rule for antenna beamwidth.137
In addition, we do not find Sutron’s argument about wind/snow effects on the LPR antenna compelling,
because this problem could be addressed by judiciously choosing an installation location that would
shield the LPR antenna from weather conditions. Accordingly, we deny Sutron’s request to increase the
antenna beamwidth limit to 35 degrees.
(ii)

Antenna Side-Lobe Gain

45.
In the FNPRM, the Commission proposed a fixed side-lobe gain limit of -10 dBi for off-
axis angles greater than 60 degrees.138 The Commission also sought comment on the necessity of
establishing limits on the gain of the antenna in the side lobe region and off-axis angles.139

131 ETSI LPR Standard at Section 7.4.1, p. 29.
132 FNPRM, supra at 3672, para. 29.
133 A wider antenna beamwidth would allow more emission scattering horizontally.
134 For the 5.925-7.250 GHz band, the expected equivalent horizontal emissions, which include antenna back-lobe
and side-lobe emissions and worst-case reflections from the material being measured, is -55 dBm EIRP. ECC
Report 139 at p. 3, ETSI LPR Technical Standard at p. 26, FNPRM, supra at para. 24.
135 Sutron comments at 2-3.
136 FNPRM, supra at 3672, para. 29. See also ECC Report 139 at p. 11, ETSI LPR Technical Standard at p. 29.
137 Hach comments at 6.
138 FNPRM, supra at 3672, para. 30.
139 Id.
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46.
Delphi, a mobile electronics and vehicle radar manufacturer, takes issue with the proposed
fixed side lobe gain limit. It contends that an inefficient antenna could allow side lobe emissions to exceed
the intended general emission limit (i.e., -41.3 dBm EIRP in 75-85 GHz band, the same as the general
15.209 emission limit) and yet still comply with the proposed fixed -10 dBi gain.140 Delphi recommends
that we specify antenna side lobe emission limits and require that these emissions be verified by
measuring the ratio of main lobe gain to side lobe gain or tested at the system level if it is determined that
side lobe emission levels can be accurately measured.141
47.
In reply, MCAA argues that Delphi’s analysis using 10% antenna efficiency is
unrealistic. MCAA contends that for a given beamwidth, and holding all other properties constant, the
gain of an antenna (as a numeric value) is directly proportional to its efficiency.142 MCAA further
observes that, in the 77-81 GHz band that Europe has authorized for short-range automotive radar
applications, radio wave propagation is subject to both high free-space attenuation143 and high attenuation
from terrain and ground clutter.144 MCAA states however that it has no objection to the Commission’s
measuring the side-lobe gain as part of the certification, so long as the measurement ascertains gain,
rather than side-lobe emissions.145
48.
We agree with Delphi that, in some cases, an LPR operating at the maximum main-beam
power as proposed in the FNPRM could have side-lobe emissions that exceed the -41.3 dBm EIRP
interference protection criteria in Section 15.209, depending on the efficiency of the antenna used and the
power at which the LPR is operated. The Commission noted in the FNPRM that it did not intend any
rule revisions adopted in this proceeding to permit the gain of any LPR side lobe to exceed the EIRP limit
in Section 15.209.146 Therefore, we will modify the side-lobe gain limits from those proposed in the
FNPRM.147 We note that antenna side-lobe gains correlate to main-beam gains; as the antenna
main-beam gain varies, the side-lobe gain also varies. Therefore, to ensure that LPRs provide the same
interference protection to authorized radio services as other Part 15 devices (i.e., maintain the
general -41.3 dBm EIRP limit from Section 15.209 on horizontal transmissions from LPRs), we adopt a
side-lobe gain limits relative to the main-lobe gain,148 as shown in Table 3 below. The calculations for
these limits are found in Appendix C.

140 Delphi calculates that for an LPR operating in the 75-85 GHz band with the required 8 degrees maximum
beamwidth, a 10% efficient antenna could allow a resulting side lobe emission of -32 dBm EIRP, which would be
10 dB above the intended general emission limit of -41.3 dBm EIRP, while still complying with the required fixed
antenna side lobe gain of -10 dBi.
141 Delphi comments at 2.
142 MCAA states that by redoing Delphi’s calculation, but with a more realistic low-value antenna efficiency of
60%, its calculations instead yield a side lobe emission of just 1.5 dB above the emission limit of -41.3 dBm EIRP.
143 There is approximately 80 dB of free space attenuation at 3 meters for an 80 GHz signal. See FNPRM, 27 FCC
Rcd at 3669 n.51.
144 MCAA reply comments at 6.
145 Id.
146 FNPRM, supra at 3670, para. 25.
147 ECC Report 139 at p. 12. We note that although ECC uses the fixed -10 dBi antenna side lobe gain as an initial
reference value in the simulations in ECC Report 139, it states that the eventual ETSI harmonized standard for LPRs
may establish a different value for side-lobe gain based on further practical measurement results.
148 If an antenna has a low main-beam gain because of losses due to inefficiency and the input power to the antenna
is increased to compensate for the loss and to attain the maximum main beam EIRP, the specified side-lobe EIRP
gain limit relative to the main beam gain has been calculated to ensure that side-lobe power is always suppressed to
less than the general emission limit of Section 15.209 (i.e., less than -41.3 dBm EIRP), even if the main beam gain is
increased up to the maximum main-beam limit. See infra Appendix C.
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Table 3 – Side Lobe Gain Limit Relative to Main Beam Gain Limit

Frequency Range
Antenna Side Lobe Gain Limit
(GHz)
Relative to Main Beam Gain
(dB)
5.925-7.250
-22
24.05-29.00
-27
75-85
-38
b.

Automatic Power Control

49.
In the FNPRM, the Commission noted that as a consequence of its proposed main-beam
emission limits, all reflected emissions from the LPR device will be kept at or below the Section 15.209
general emission limits, and thus it did not to propose to adopt automatic power control (APC)
requirements for LPR devices. The Commission sought technical analyses from parties advocating a
requirement for APC to show the inadequacy of the emission limit in Section 15.209.149 No party
provided comments on APC. Accordingly, we do not adopt APC requirements for LPR devices.
3.

Other Requirements

b.

Operational and Marketing Restrictions

50.
In the FNPRM, the Commission proposed, for LPR devices authorized under the higher
emission limits in the new rule, that the antenna of an LPR device be dedicated or integrated as part of the
transmitter and professionally installed in a downward position; to limit installations of LPR devices to
fixed locations; to prohibit hand-held applications of LPR devices; and to prohibit the marketing of LPR
devices to residential consumers. It stated that these restrictions are intended to protect incumbent
authorized services operating in the same and adjacent frequency bands from potential harmful
interference from LPRs.150 As we discuss below, we will require the antenna of an LPR device to be
dedicated or integrated as part of the transmitter; limit installations of LPR devices to fixed locations;
prohibit hand-held applications of LPR devices; and prohibit the marketing of LPR devices to residential
consumers. A requirement for professional installation appears unnecessary as we are requiring LPRs to
be installed in a downward position and LPRs would not function correctly if they are not pointed down
toward the substance to be measured. Accordingly, we are not adopting a requirement for professional
installation.
51.
CORF specifically supports the proposals that the LPR antenna be dedicated or integrated
as part of the transmitter and professionally installed in a downward position; to limit installations of LPR
devices to fixed locations; to prohibit hand-held applications of LPR devices; and to prohibit the
marketing of LPR devices to residential consumers.151 EIBASS argues that the proposed requirement for
“professional installation” is meaningless unless there is a requirement for LPRs operating at 6.6 GHz
under the higher emission limits to produce upon FCC request a record showing the qualifications of the
person making the installation and when the installation took place.152 EIBASS also recommends that
LPRs operating in the 6 GHz frequency range include a built-in circuit that would not allow the LPR to

149 FNPRM, supra at 3672, para. 31.
150 Id., at 3673, para. 34.
151 CORF comments at 4; see also NRAO reply comments at 2.
152 EIBASS comments at para. 7. EIBASS recommends that to meet such qualifications, the “professional” installer
of LPRs should be a person holding certification from either the Society of Broadcast Engineers (SBE) at the
broadcast engineer level or higher, or the National Association of Radio and Television Engineers (NARTE) as an
Electromagnetic Compatibility (EMC) engineer, or be registered as a Professional Engineer (PE). Id., at para. 6.
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transmit if the transmitting antenna is not within + 10 degrees of straight downwards.153
52.
We conclude that the LPR antenna must be dedicated or integrated as part of the
transmitter. We do so because, as we explain above, antennas used in LPR devices must satisfy the
requirements for main-beam radiated emissions, beamwidth and side-lobe gain, which are interdependent,
to demonstrate compliance with new Section 15.256. By requiring a dedicated or integrated antenna as
part of the transmitter, we will ensure that the LPR when operated will meet the emission limits necessary
to protect authorized users. We also conclude that there is no need to adopt a rule to require professional
installation of LPR. We observe that the Commission has not adopted a specific definition for
“professional installation” in any of our rules for unlicensed devices but has rather left it to be assessed on
a case-by-case basis as a certification grant condition.154 Here, LPR devices are commercial products
intended to measure industrial types of materials such as coal, gravel, sand piles or waterways such as
rivers or dams, and the rules we adopt herein prohibit their marketing to residential consumers. We also
find that the installation of these devices is relatively simple, and because they are commercial products,
they will typically be handled by people with product knowledge, unlike many Part 15 devices that have
consumer-oriented applications. Further, we are prohibiting the marketing of LPR devices to residential
consumers. We therefore find that the operational and marketing restrictions placed on LPR devices are
sufficient to avoid harmful interference to authorized radio services without imposing the requirement for
professional installation on LPR devices. We also observe that by its operating nature, an LPR device
must be directed toward the substance being measured; the device would not operate correctly if there are
too many false echoes caused by reflections from various neighboring physical objects. Thus, installation
errors or unintentional misuse of the product will require correction to operate effectively and would need
no additional hardware or software safeguard. We are also requiring in the rules adopted herein that
LPRs be installed in a downward position. However, we find that additionally requiring built-in circuits
to prevent transmission in case of installation errors as recommended by EIBASS an unnecessary cost
without correlating benefits.
53.
EIBASS also states that while some LPRs appear large enough to make hand-held or
mobile applications unlikely, others are clearly small enough to be operated as a non-fixed device, and
violation of the hand-held restriction in the LPR rules could cause interference to a TV station’s
studio-to-transmitter links (STL).155 EIBASS therefore recommends that LPRs operating in the 6 GHz
frequency range include a built-in circuit to ensure that the LPR is stationary (i.e., it would detect motion
if the LPR device is used in a hand-held fashion).156
54.
We conclude that LPR devices should only be operated when installed in fixed locations,
and thus we will prohibit hand-held and mobile applications to prevent interference to authorized services
in the same or adjacent frequency bands. The record supports this conclusion. YSI Incorporated (YSI)
urges us to confirm that “fixed” also means temporary fixed installations, to allow users the flexibility to
operate an LPR at different locations to meet diverse measurement needs, without requiring it to remain
permanently at a specific fixed location.157 We clarify that an LPR may be temporarily affixed to a
structure, so long as it operates only when at a fixed location as required by the rules. We are prohibiting
hand-held applications since these could increase the potential for harmful interference to authorized
radio services; they could easily be moved, operated while in motion, or operated when not pointed
straight downward. The same concerns apply to operating an LPR while it is moving (e.g., while being
transported inside a tanker truck), and the rules will prohibit such use. Because we believe that misuse of

153 Id., at para. 4.
154 See e.g., 47 C.F.R. §§ 15.203, 15.231, 15.247 and 15.711.
155 EIBASS comments at para 5.
156 Id., at para. 4.
157 YSI comments at 3-4.
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an LPR will render it ineffective and thus is quite unlikely to be pursued or to occur, we find that
requiring built-in circuits to detect motion as recommended by EIBASS is an unnecessary cost without
sufficient correlating benefits.158
55.
EIBASS also argues that the Commission lacks jurisdiction when it comes to the
advertisement of Part 15 devices that are already approved, and submits that the Commission’s authority
ends after a device has obtained certification. EIBASS contends that even if the manufacturer of the
Part 15 device complies with the marketing requirement and sells only to industrial users, the
manufacturer has no control over second-tier distributors. EIBASS is therefore concerned about
expanded commercial use that does not comply with the marketing restrictions for LPR.159
56.
We disagree with EIBASS’ assertion that the Commission lacks authority to prohibit
marketing of LPR devices to certain types of customers or for certain types of applications. We note that
Congress granted the Commission authority to regulate the marketing, offering for sale, sale or use of RF
devices in Section 302 of the Communications Act,160 and the Commission implemented that authority in
Section 2.803 of its rules.161 Further, as an unlicensed Part 15 device, an LPR is subject to the provisions
of Section 15.5 of the rules, which require the user of a transmitter that causes interference to authorized
radio communications to stop operating the transmitter or correct the problem causing the interference.162
The Commission has the authority to investigate Part 2 and Part 15 violations and take action accordingly,
including imposing fines and penalties through its Enforcement Bureau’s actions.163 Therefore, the rules
provide several safeguards against the improper use of an LPR (e.g., using it for hand-held applications),
that could result in harmful interference to authorized spectrum services.
a.

Equipment Certification

57.
In the FNPRM, we proposed to permit Telecommunications Certification Bodies (TCBs)
to certify LPR devices operating under the proposed rules.164 We noted that the FNPRM proposals
specify direct measurement of emissions within the main beam of the LPR antenna and are consistent
with compliance measurement methodologies currently used by TCBs with other types of unlicensed

158 EIBASS contends that the FNPRM cost-benefit analysis fails to consider the costs to incumbent TV BAS
licensees in tracking down harmful interference caused by unlicensed high power LPRs. However, EIBASS
concedes that tracking down interference from a stationary, continuously radiating IX source is far easier than trying
to locate interference from a mobile or intermittently transmitting device. EIBASS comments at para. 11. We do
not anticipate that BAS licensees will incur costs to investigate interference from LPR because, as we discuss above,
we do not anticipate that LPRs will cause harmful interference to BAS.
159 Id. at para. 9-10.
160 47 U.S.C. § 302a. Section 302 of the Communications Act of 1934, as amended, states that the Commission
may, consistent with the public interest, convenience, and necessity, make reasonable regulations governing the
interference potential of devices which in their operation are capable of emitting RF energy by radiation,
conduction, or other means in sufficient degree to cause harmful interference to radio communications. 47 U.S.C. §
302a(a). It further states that no person shall manufacture, import, sell, offer for sale, or ship devices or home
electronic equipment and systems, or use devices, which fail to comply with regulations promulgated under this
section. This provision of the law is intended to prevent devices that could cause harmful interference to radio
communications from reaching the marketplace or being operated. 47 U.S.C. § 302a(b).
161 47 C.F.R. § 2.803.
162 47 C.F.R. § 15.5.
163 See 47 U.S.C. §§ 501-503, 510.
164 FNPRM, supra at 3672-3673, para. 35. TCBs are accredited third-party product certification bodies authorized to
issue a grant of certification for certain products in lieu of a traditional grant issued by the Commission. 47 C.F.R.
§§ 2.1031-2.1060.
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transmitters.165 We continue to hold this view, and we will allow LPR equipment certification by TCBs in
addition to the Commission. We note that no comment was received on this proposal.
58.
In the FNPRM, the Commission recognized that, currently, a certified TLPR device could
be approved to operate under other conditions, e.g., outdoor installations in open-air environments, in an
enclosure with low RF attenuation characteristics, or with higher power. To allow previously-certified
devices to take advantage of any changes proposed in the FNPRM and adopted in this Order, the
Commission proposed to allow the responsible party to file for a permissive change166 in accordance with
the existing rules and practices, provided that: (1) the LPR device operates only within the frequency
bands authorized by rules proposed herein; (2) measurement data taken in accordance with the
measurement procedure proposed above is provided to demonstrate compliance with the new emission
limits specified in these proposed rules; and (3) operational changes to the device are being implemented
by software upgrade without any hardware change.167 We continue to believe that these provisions are
appropriate because, consistent with our existing practice, they minimize additional certification burdens
on applicants without causing an increased potential for harmful interference to authorized services. We
will implement the above changes in our equipment certification guidelines for LPRs. We also note that
no comment was received on this proposal.
b.

Additional Protection for the Radio Astronomy Service (RAS)

59.
Distance Separation and Height Restrictions. As noted above,168 CORF notes that RAS
has primary allocations at 76-77.5 GHz and 78-85 GHz and does not oppose sharing these bands with
LPRs provided the Commission adopts certain protections designed to ensure that RAS can operate in the
interference-free environment that the service requires for picking up extremely weak signals.169 More
specifically, CORF and NRAO request that these protections include exclusion zones around RAS

165 Id. In the Notice and Order, we instead proposed to require that TLPR devices designed to operate in the
77-81 GHz band be certified by the Commission's Laboratory rather than by TCBs. We noted that, because a
standard test procedure for LPR devices had not yet been devised for use at these frequencies at that time, this
requirement would give the Commission time to develop appropriate measurement guidelines for devices intended
for operation in this frequency band. Notice and Order, supra at 610, para. 24. In the FNRPM, however, the
Commission observed that the new proposals made in the FNPRM would facilitate the direct measurement of LPR
emissions within the main beam of the antenna and were consistent with compliance measurement methodologies
used with other types of unlicensed transmitters. FNPRM, supra at 3674, para. 35. Accordingly, the Commission
proposed to permit TCBs to certify LPR devices for the proposed operations in the 77-81 GHz band. Id.
166 47 C.F.R. § 2.1043 defines three classes of permissive changes that may be made without obtaining a new grant
of equipment authorization and labeling a device with a new FCC identification number. The three classes of
permissive changes are: (1) Class I, which includes those modifications in the equipment that do not degrade the
characteristics reported by the manufacturer and accepted by the Commission when certification is granted; (2)
Class II, which includes those modifications that degrade the performance characteristics as reported to the
Commission at the time of the initial certification; and (3) Class III, which includes modifications to the software of
a software defined radio transmitter that change the frequency range, modulation type, or maximum output power
(either radiated or conducted) outside the parameters previously approved or that change the circumstances under
which the transmitter operates in accordance with Commission rules. 47 C.F.R. § 2.1043(b). No filing is required
with the Commission or a TCB for a Class I permissive change. Class II and III permissive changes require an
abbreviated filing with the Commission or a TCB and an acknowledgement that the changes are acceptable before
the changed equipment can be marketed but do not require a complete application for certification or new FCC
identification number. Class III permissive changes are not permitted on a device that has had a Class II permissive
change. See also, Knowledge Data Base (KDB) No. 178919 at
https://apps.fcc.gov/oetcf/kdb/forms/FTSSearchResultPage.cfm?id=33013&switch=P.
167 FNPRM, supra at 3674, para. 36.
168 See para. 28, supra.
169 CORF comments at 1-3.
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stations, restrictions on the height of LPR antennas, requirements for antenna installation, a restriction of
operations to fixed installations only, and the deployment of a publicly accessible database of all LPR
installations. CORF and NRAO state that the ECC Report 139 recommends a geographical region in
which LPRs cannot be installed within 4 km from RAS locations and a limit of 15 meters above ground
level on LPR antenna height within 40 km of these locations.170 They request that the Commission
require the same distance separation and height restrictions to protect RAS stations, particularly in the
6650-6675.2 MHz171 (part of the 5.925-7.250GHz band) and 75-85 GHz bands.172 MCAA, which
represents the LPR industry, agrees with the separation distance and height restrictions to protect RAS
sites.173
60.
The Commission did not propose these restrictions in the FNPRM because interference to
RAS observatories from downward-looking LPRs is unlikely. First, the ETSI/ECC distance and antenna
height limitation requirements are based on the RAS operating environment in Europe where RAS sites
are typically found in urban areas; this is a different environment than in the United States, where RAS
receivers are commonly located in remote or rural areas, not the industrial areas where LPRs are likely to
be found. Second, in the FNRPM, the Commission proposed radiated emission limits for LPRs, designed
to ensure that, at 3 meters from the LPR, the reflected emission level is less than the existing general limit
of -41.3 dBm EIRP of Section 15.209, which is the limit currently applicable to Part 15 devices, such as
computers and video monitors, which are likely being used inside a RAS site, apparently without harm.
Third, RAS receivers discriminate against off-beam signals and are pointed skyward, discriminating
against reflected signals that would be reflected from the side or below. Even in the case of LPRs
installed over waterways in remote areas, because the radio astronomy observatories typically have
control over access to a distance of one kilometer from the telescopes to provide protection from
interference caused by uncontrolled RFI sources,174 the potential for interference caused by LPRs at that
distance (one kilometer) would be infinitesimal, when also taking into account the variability in
propagation characteristics due to terrain, weather and other factors.175 Given these factors and the
additional operational and marketing restrictions on LPR devices that we are adopting herein (e.g.,
integrated antennas, downward operation, prohibition on marketing to consumers), we do not find that it
is necessary to also prohibit LPRs by rule to avoid operating in the line of sight of RAS stations as NRAO
requested.176 While the MCAA does not oppose the restrictions proposed by CORF and NRAO, MCAA
represents only a segment of current LPR users of the band and does not necessarily anticipate future
uses. Accordingly, we are denying CORF and NRAO’s requests for separation distances from radio
astronomy observatories and for a limitation on LPR antenna height within certain distances of the line of
sight of RAS stations.

170 CORF comments at 6, NRAO comments at 3. CORF comments are mostly concerned with the 75-85 GHz band.
171 Although the radio astronomy service (RAS) has no allocation in the 6650-6675.2 MHz band, NRAO observes
that footnote US 342 to the Table of Frequency Allocations states that “all practicable steps shall be taken to protect
the radio astronomy service from harmful interference.” NRAO comments at 2.
172 With respect to the specific bands mentioned for operation of LPR, radio astronomy has primary spectrum
allocations over the entirety of the region 76-85 GHz, except at 77.5-78 GHz where it is secondary. Id.
173 MCAA comments at 3-4, MCAA reply comments at 5.
174 See Amendment of Parts 2, 15 and 97 of the Commission’s Rules to Permit the Use of Radio Frequencies Above
40 GHz for New Radio Applications
, Third Memorandum Opinion and Order, ET Docket No. 94-124,
15 FCC Rcd 10515, 10517-18, para. 8 and n.15 (2000).
175 At d= 1000 m and f = 76.50 GHz, free-space path loss is approximately 130 dB. See also Amendment of Sections
15.35 and 15.253 of the Commission’s Rules Regarding Operation of Radar Systems in the 76-77 GHz Band and
Amendment of Section 15.253 of the Commission’s Rules to Permit Fixed Use of Radar in the 76-77 GHz Band
,
Report and Order, ET Docket Nos. 11-90 and 10-28, 27 FCC Rcd 7880, 7885, para. 15 (2012).
176 NRAO comments at 3.
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61.
LPR Installation Database. CORF and NRAO request that we implement a publicly
available LPR installation database so that RAS operators can readily identify sources of interference to
their stations should interference occur.177 They point out that the Commission required LPR
manufacturers to maintain such information and make it available to the Commission upon request when
we granted waivers to TLPR manufacturers to operate in the 77-81 GHz band.178 NRAO recognizes the
likely diversity of LPR vendors, installers and providers but continues to request that given the limited
number of RAS sites, only installations within 40 km of RAS sites need to be identified by sending an
email or a letter to the Spectrum Management Office at the National Science Foundation (NSF).179
MCAA and Krohne strongly oppose these requests for a database of LPR installation sites. Krohne states
that its customers, especially governmental users, need to protect their sensitive operational data, which
often include the location of tanks and storage facilities. Krohne also rejects NRAO’s suggestion to just
receive a letter or an email of new location installations, citing the cost burden, as well as the same type of
confidentiality concerns that it raised with respect to the proposal for a public database. MCAA states
that many installations are performed by third-party companies, so the manufacturers have no reliable
mechanism for maintaining location data.
62.
We decline to require a publicly available LPR installation database or to require
manufacturers to maintain lists of LPR installation sites. We note that it is customary for the Commission
to proceed in a very cautious manner in a waiver proceeding by imposing specific conditions on
operations that typically involve new technology products or new applications of existing technologies
and with which the Commission may have little or no prior experience regulating. In the case of the
waiver grant for TLPR devices operating in the 77-81 GHz band, we required manufacturers to maintain a
list of LPR installation sites as an additional safeguard to permitting LPR operations in a restricted band,
even though we expected that TLPR devices would not be operating in close proximity to radio
astronomy sites and thus not likely to cause harmful interference to them.180 As we discuss above in the
Report and Order, we are adopting new rules based on ETSI/ECC’s analysis which derived the limits for
LPR main-beam emissions by mathematically correlating them with reflected emissions from an LPR; the
resulting values are the same as the existing Part 15 average emission limit.181 The LPR main-beam
emission limits therefore would maintain the existing level of interference protection to incumbent radio
services, including RAS sites -- a level that has already proven to be adequate. We find that NRAO’s
recommendation that the NSF be notified of each LPR installation site is an unnecessary cost without
countervailing benefits, and agree with the LPR industry that this could give rise to confidentiality issues.
We conclude that the downward-looking operation of LPRs at such emission limits, when combined with
the various operating/marketing restrictions, is extremely unlikely to cause harmful interference to radio
astronomy telescopes, thereby making a database or list of LPR installation sites, or notification to
authorized users unnecessary. Further, we find that our decision not to require a publicly available
database addresses the LPR industry’s concern over potential security risks from the disclosure of LPR
locations.
63.
Cost Benefit Analysis. In the FNPRM, the Commission provided an analysis on the
potential costs of the proposed LPR regulation versus its potential benefits.182 The Commission stated
that, because LPR devices need higher power and wider bandwidth than that which is permitted under the
existing Part 15 rules to fully achieve the potential of this measuring technology, the proposed rules

177 CORF comments at 4-5; NRAO comments at 3.
178 Notice and Order, supra at 614, para. 38.
179 NRAO reply comments at 2.
180 Notice and Order, supra at 614, para. 38.
181 See supra para. 33, note 102.
182 FNPRM, supra at 3674-75, para. 37.
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would tender a necessary remedy for LPR devices to operate at the power levels and in the appropriate
frequency bands required to deliver the needed accuracy for diverse applications, thereby promoting the
expanded development and use of this technology to the benefit of businesses, consumers, and the
economy. The Commission tentatively concluded that the proposed higher power levels in the proposed
frequency bands would further the development of better and improved level-measuring tools, but these
changes would not increase the potential for interference to authorized users beyond what is permitted
under the current rules. The Commission also considered how the proposed rules would help to simplify
equipment development and certification of LPR devices, as well as provide a simplified method for
measuring the radiated emissions from these devices.183
64.
Except for a comment from EIBASS, none of the commenters took issue with any of
these factors or with our tentative conclusion. As we discussed above,184 EIBASS argues that the FNPRM
cost-benefit analysis fails to consider the costs to incumbent TV BAS licensees in the 6 GHZ frequency
range in tracking down harmful interference caused by unlicensed high power LPRs.185 We do not
anticipate, however, that BAS licensees will incur costs to investigate interference from LPR; we do not
find that LPRs will cause harmful interference to BAS or any other licensed user in any of the adopted
frequency bands for LPR operation, as discussed at length, above.186 We conclude that the rules adopted
herein will provide significant benefits to LPR manufacturers and users with no apparent cost to any
party.

IV.

ORDER

65.
In this Order, we are dismissing a waiver request from VEGA to operate LPR devices in
the 24.6-27 GHz frequency band under Section 15.252 as moot. The Commission previously held this
request in abeyance pending final action in this rulemaking proceeding because this waiver raises issues
that are, in part, similar to those raised in the FNPRM.187
66.
VEGA requested a waiver of Section 15.252(a) to operate LPR devices in the
24.6-27 GHz frequency band under this section as a fixed structure, either in tanks or in open air.188
Section 15.252(a) permits the use of field disturbance sensors within the frequency bands 16.2-17.7 GHz
and 23.12-29.0 GHz but requires them to be mounted in terrestrial transportation vehicles, whereas
VEGA’s LPR devices would only be installed at fixed locations.189 The waiver request also proposed an
emission method of measurement that does not take into account boresight emissions. After the release of
the FNPRM, VEGA amended this waiver request on June 6, 2012 for permission to market its 6 GHz and
26 GHz LPRs that would comply with the proposed rules.190 Because the rules we adopt in this Report
and Order will enable VEGA to operate LPR devices in the 24.6-27 GHz frequency band without a

183 Id.
184 See supra at para. 54, note 158.
185 However, EIBASS concedes that tracking down interference from a stationary, continuously radiating IX source
is far easier than trying to locate interference from a mobile or intermittently transmitting device. EIBASS
comments at para. 11.
186 See e.g., supra at paras. 15, 34 and 36.
187 FNPRM, supra at 3664, para. 9.
188 See Ohmart/VEGA Corporation Request for Waiver of Section 15.252 to Permit the Marketing of Level Probing
Radars in the 26 GHz Band
, ET Docket No. 10-27; see also supra n. 20. After the adoption of the FNPRM,
Ohmart/VEGA amended this waiver on April 26, 2012, to request immediate operation under the FNPRM’s
proposed rules pending the conclusion of this rulemaking. Id.
189 47 C.F.R. § 15.252(a).
190 Ohmart/VEGA Corporation Request for Waiver of Section 15.252 to Permit the Marketing of Level Probing
Radars in the 26 GHz Band
, ET Docket No. 10-27; see also supra n. 20.
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waiver of the usage restrictions in Section 15.252(a), VEGA will be able to apply for LPR certification
under new Section 15.256 for both in tank and open air applications. Accordingly, we dismiss VEGA’s
waiver request as moot.

V.

PROCEDURAL MATTERS

67.
Final Regulatory Flexibility Analysis. As required by Section 603 of the Regulatory
Flexibility Act, 5 U.S.C. § 603, the Commission has prepared a Final Regulatory Flexibility Analysis
(IRFA) of the possible significant economic impact on small entities of the changes adopted in this
document. The FRFA is set forth in Appendix A.
68.
Paperwork Reduction Analysis. This document contains no new or modified information
collection requirements 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).
69.
Congressional Review Act. The Commission will send a copy of this Report and Order in
a report to be sent to Congress and the Government Accountability Office pursuant to the Congressional
Review Act, see 5 U.S.C. 801(a)(1)(A).

VI.

ORDERING CLAUSES

70.
IT IS ORDERED that pursuant to Sections 4(i), 301, 302, 303(e), 303(f), 303(g), and
303(r) of the Communications Act of 1934, as amended, 47 U.S.C. Sections 154(i), 301, 302a, 303(e),
303(f), 303(g), and 303(r), this Report and Oder is hereby ADOPTED and Part 15 of the Commission’s
Rules ARE AMENDED as set forth in Appendix D, effective 30 days after publication in the Federal
Register.
71.
IT IS FURTHER ORDERED that pursuant to authority in Section 1.3 of the
Commission's rules, 47 C.F.R. Section 1.3, and Sections 4(i), 302, and 303(e), of the Communications
Act of 1934, as amended, 47 U.S.C. Sections 154(i), 302, and 303(e), the Request for Waiver filed by
VEGA Americas, Inc. (formerly Ohmart/VEGA Corporation) filed on December 3, 2009, IS
DISMISSED, consistent with the terms of this Order. This action is effective upon release of this Order.
72.
IT IS FURTHER ORDERED that the Commission’s Consumer and Governmental
Affairs Bureau, Reference Information Center, SHALL SEND a copy of this Report and Order, including
the Final 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

Final Regulatory Flexibility Analysis

1.
As required by the Regulatory Flexibility Act (RFA),1 an Initial Regulatory Flexibility
Analysis (IRFA) was incorporated in the Further Notice of Proposed Rulemaking (FNPRM) in ET
Docket No. 10-23.2 The Commission sought written public comment on the proposals in the FNPRM,
including comment on the IRFA. This present Final Regulatory Flexibility Analysis (FRFA) conforms to
the RFA.

A.

Need for, and Objectives of, the Report and Order

2.
In this Report and Order, we modify our rules to provide a set of new technical and
operational rules to govern the operation of level probing radar (LPR) devices installed both in open-air
environments and inside storage tanks (TLPR applications) in the following frequency bands:
5.925-7.250 GHz, 24.05-29.00 GHz, and 75-85 GHz. To permit LPR operation in the 75-85 GHz band,
we also modify the existing Section 15.205 of the rules to remove the prohibition on intentional emissions
in this band. The amended rules will allow devices with accurate and reliable target resolution to identify
water levels in rivers and dams or critical levels of materials such as fuel or sewer-treated waste, reducing
overflow and spillage and minimizing exposure of maintenance personnel in the case of high risk
substances. The amended rules would also, to the extent practicable, harmonize our technical rules for
LPR devices with similar European standards and would improve the competitiveness of U.S.
manufacturers in the global economy, leading to potential cost savings for small businesses, all without
causing harmful interference to authorized spectrum users in the affected frequency bands.

B.

Statement of Significant Issues Raised by Public Comments in Response to the IRFA

3.
There were no public comments filed that specifically addressed the rules and policies
proposed in the IRFA.

C.

Response to Comments by the Chief Counsel for Advocacy of the Small Business

Administration

4.
Pursuant to the Small Business Jobs Act of 2010, the Commission is required to respond
to any comments filed by the Chief Counsel for Advocacy of the Small Business Administration, and to
provide a detailed statement of any change made to the proposed rules as a result of those comments. The
Chief Counsel did not file any comments in response to the proposed rules in this proceeding.

D.

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

5.
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 proposed rules, if adopted.3 The RFA defines the
term “small entity” as having the same meaning as the terms “small business,” “small organization,” and

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), Public Law No. 104-121, Title II, 110 Stat. 857 (1996), and the
Small Business Jobs Act of 2010, Public Law No. 111-240, 124 Stat. 2504 (2010).
2 Further Notice of Proposed Rulemaking in ET Docket No. 10-23 (In the Matter of Amendment of Part 15 of the
Commission’s Rules To Establish Regulations for Tank Level Probing Radars in the Frequency Band 77-81 GHz
and Amendment of Part 15 of the Commission’s Rules To Establish Regulations for Level Probing Radars and Tank
Level Probing Radars in the Frequency Bands 5.925-7.250 GHz, 24.05-29.00 GHz and 75-85 GHz)
, 27 FCC Rcd.
3660 (2012) (FNPRM).
3 See 5 U.S.C. § 603(b)(3).
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“small business concern” under Section 3 of the Small Business Act.4 Under the Small Business Act, a
“small business concern” is one that: (1) is independently owned and operated; (2) is not dominant in its
field of operations; and (3) meets may additional criteria established by the Small Business
Administration (SBA).5
6.

Small Businesses, Small Organizations, and Small Governmental Jurisdictions.

Our
action may, over time, affect small entities that are not easily categorized at present. We therefore
describe here, at the outset, three comprehensive, statutory small entity size standards that encompass
entities that could be directly affected by the proposals under consideration.6 As of 2009, small
businesses represented 99.9% of the 27.5 million businesses in the United States, according to the SBA.7
Additionally, a “small organization” is generally “any not-for-profit enterprise which is independently
owned and operated and is not dominant in its field.”8 Nationwide, as of 2007, there were approximately
1,621,315 small organizations.9 Finally, the term “small governmental jurisdiction” is defined generally
as “governments of cities, counties, towns, townships, villages, school districts, or special districts, with a
population of less than fifty thousand.”10 Census Bureau data for 2007 indicate that there were 89,527
governmental jurisdictions in the United States.11 We estimate that, of this total, as many as 88,761
entities may qualify as “small governmental jurisdictions.”12 Thus, we estimate that most governmental
jurisdictions are small.
7.
The adopted rules pertain to manufacturers of unlicensed communications devices. The
appropriate small business size standard is that which the SBA has established for 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

4 Id. § 601(3).
5 Id. § 632.
6 See 5 U.S.C. § 601(3)–(6).
7 See SBA, Office of Advocacy, “Frequently Asked Questions,” available at
http://web.sba.gov/faqs/faqindex.cfm?areaID=24 (last visited Aug. 31, 2012).
8 5 U.S.C. § 601(4).
9 INDEPENDENT SECTOR, THE NEW NONPROFIT ALMANAC & DESK REFERENCE (2010).
10 5 U.S.C. § 601(5).
11 U.S. CENSUS BUREAU, STATISTICAL ABSTRACT OF THE UNITED STATES: 2011, Table 427 (2007).
12 The 2007 U.S Census data for small governmental organizations are not presented based on the size of the
population in each such organization. There were 89,476 local governmental organizations in 2007. If we assume
that county, municipal, township, and school district organizations are more likely than larger governmental
organizations to have populations of 50,000 or less, the total of these organizations is 52,095. If we make the same
population assumption about special districts, specifically that they are likely to have a population of 50,000 or less,
and also assume that special districts are different from county, municipal, township, and school districts, in 2007
there were 37,381 such special districts. Therefore, there are a total of 89,476 local government organizations. As a
basis of estimating how many of these 89,476 local government organizations were small, in 2011, we note that
there were a total of 715 cities and towns (incorporated places and minor civil divisions) with populations over
50,000. CITY AND TOWNS TOTALS: VINTAGE 2011 – U.S. Census Bureau, available at
http://www.census.gov/popest/data/cities/totals/2011/index.html. If we subtract the 715 cities and towns that meet
or exceed the 50,000 population threshold, we conclude that approximately 88,761 are small. U.S. CENSUS
BUREAU, STATISTICAL ABSTRACT OF THE UNITED STATES 2011, Tables 427, 426 (Data cited therein are
from 2007).
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broadcasting equipment.”13 The SBA has developed a small business size standard for firms in this
category, which is: all such firms having 750 or fewer employees.14 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, 784 had less than 500 employees and 155 had more than 100 employees.15 Thus,
under this size standard, the majority of firms can be considered small.

E.

Description of Projected Reporting, Record keeping and Other Compliance Requirements

for Small Entities
8.
Unlicensed devices operating in the 5.925-7.250 GHz and 24.05-29.00 GHz band are
already required to be authorized under the Commission's certification procedure as a prerequisite to
marketing and importation, and the Report and Order makes no change to that requirement. See 47
C.F.R. §§ 15.101, 15.201, 15.250, and 15.252. Currently, the 75-85 GHz band is a restricted band in
which unlicensed device may not only transmit spurious (unintentional) emissions. The Report and Order
modifies the existing Section 15.205, 47 C.F.R. § 15.205, of the rules to remove the prohibition on
intentional emissions in this band and adopt the same certification procedures for level probing radars
operating in this band as for the other above-listed frequency bands. The technical requirements adopted
in this Report and Order, as discussed below, do not impose significant burden and will not have a
significant economic impact on a substantial number of small entities that are, or may be, subject to the
requirements of the rules in the item.

F.

Steps taken to Minimize Significant Economic Impact on Small Entities and Significant

Alternatives Considered

9.
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, standards; and (4) an exemption from coverage of the rule, or any part thereof, for small
entities.16
10.
In this Report and Order, we modify our rules to provide a set of new technical and
operational rules to govern the operation of LPR devices installed both in open-air environments and
inside storage tanks (TLPR applications) in the following frequency bands: 5.925-7.250 GHz,
24.05-29.00 GHz, and 75-85 GHz. To permit LPR operation in the 75-85 GHz band, we also modify the
existing Section 15.205 of the rules to remove the prohibition on intentional emissions in this band.
These rule changes will provide needed flexibility and cost savings for LPR devices, benefiting the U.S.
consumers and manufacturers without causing harmful interference to authorized services. The amended
rules will allow devices with accurate and reliable target resolution to identify water levels in rivers and
dams or critical levels of materials such as fuel or sewer-treated waste, reducing overflow and spillage
and minimizing exposure of maintenance personnel in the case of high risk substances. The amended
rules would also, to the extent practicable, harmonize our technical rules for LPR devices with similar

13 U.S. Census Bureau, 2007 NAICS Definitions, “334220 Radio and Television Broadcasting and Wireless
Communications Equipment Manufacturing”; http://www.census.gov/naics/2007/def/ND334220.HTM#N334220.
14 13 C.F.R. § 121.201, NAICS code 334220.
15 http://factfinder.census.gov/servlet/IBQTable?_bm=y&-fds_name=EC0700A1&-geo_id=&-_skip=300&;-
ds_name=EC0731SG2&-_lang=en.
16 5 U.S.C. § 603(c).
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European standards and would improve the competitiveness of U.S. manufacturers in the global economy,
leading to potential cost savings for small businesses. We find that the benefits of the above changes to
the rules outweigh their regulatory costs. We believe that the adopted rules will apply equally to large
and small entities. Therefore, there is no inequitable impact on small entities.
11.

Report to Congress

: The Commission will send a copy of the Report and Order, including
this FRFA, in a report to be sent to Congress pursuant to the Congressional Review Act.17 In addition, the
Commission will send a copy of the Report and Order, including this FRFA, to the Chief Counsel for
Advocacy of the SBA. A copy of the Report and Order and FRFA (or summaries thereof) will also be
published in the Federal Register.18

17 See 5 U.S.C. § 801(a)(1)(A).
18 See 5 U.S.C. § 604(b).
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APPENDIX B

Parties Submitting Comments

Comments

1. Delphi Automotive (Delphi)
2. Engineers for the Integrity of Broadcast Auxiliary Services Spectrum (EIBASS)
3. Emerson Process Management (Emerson)
4. Hach Company (Hach)
5. High Sierra Electronics (High Sierra)
6. Krohne America, Inc. (Krohne)
7. Magnetrol International, Incorporated (Magnetrol)
8. Measurement, Control & Automation Association (MCAA)
9. National Academy of Science’s Committee on Radio Frequencies (CORF)
10. National Radio Astronomy Observatory (NRAO)
11. Siemens Milltronics Process Instruments (Siemens)
12. Sutron Corporation (Sutron)
13. VEGA Americas, Inc. (formerly Ohmart/VEGA Corporation) (VEGA)
14. YSI Incorporated (YSI)

Reply Comments

1. Hach Company (Hach)
2. Krohne America, Inc. (Krohne)
3. Magnetrol International, Incorporated (Magnetrol)
4. Measurement, Control & Automation Association (MCAA)
5. National Radio Astronomy Observatory (NRAO)
6. O3b Limited (O3b)
7. Siemens Milltronics Process Instruments (Siemens)
8. Sutron Corporation (Sutron)
9. VEGA Americas, Inc. (formerly Ohmart/VEGA Corporation) (VEGA)
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APPENDIX C

Antenna Side-Lobe Gain

1.
Antennas can produce emissions in unwanted directions due to side lobes. The side lobes
are smaller beams that are away from the main beam. A good (highly efficient) antenna would
concentrate power into the main beam and limit the number of side lobes as well as suppress side lobe
emissions to very low levels, but could never completely eliminate them.
2.
Although an LPR operates in a downward direction and is constrained to a narrow
beamwidth, there are horizontal emissions from the LPR antenna side lobes. These emissions can be
controlled by a side-lobe gain limit, such that side-lobe emissions are suppressed to less than the general
emission limit in Section 15.209 (i.e., -41.3 dBm EIRP), which has been established as the minimum
interference protection level to authorized radio services from unlicensed operations above 960 MHz.
3.
The proposed rules require that the LPR antenna beamwidth be less than 8 degrees for the
75-85 GHz band and less than 12 degrees for the 24.05-29.00 GHz and 5.925-7.250 GHz bands. The
proposed rules also require a fixed -10 dBi side-lobe gain for elevation angles greater than 60 degrees.
4.
To achieve the above required antenna beamwidths, a parabolic antenna with 100 %
efficiency must have a certain minimum gain. For an LPR operating at the maximum EIRP power with a
parabolic antenna at the minimum main beam gain required to meet the maximum beamwidth limit, the
table below shows the maximum side-lobe gain limit when it is specified relative to the main beam gain
rather than an absolute gain limit of -10 dBi and the difference between the two limits.

Table 2 – Fixed Side-Lobe Gain vs. Relative Side-Lobe Gain

A
B
C
D
E
F
G
Frequency Main Beam
Side lobe
Minimum
Relative Side
Side lobe
Difference
Band
EIRP Limit
EIRP Limit
Main Beam
lobe Gain
Gain
between
(GHz)
(dBm/MHz) (dBm/MHz)
Gain
Limit
Limit
Fixed -10 dBi
(Note 1)
(Note 2)
(dBi)
(dB)
(dBi)
Proposed
(Note 3)
(C) – (B)
(D) + (E)
Limit and
Relative Side
Lobe Gain
(dB)
(-10 – (F))
5.925-
-33
-55
22.7
-22
0.7
-10.7
7.250
24.05-
-14
-41
22.7
-27
-4.3
-5.7
29.00
75-85
-3
-41
26.3
-38
-11.7
1.7
Notes:
1. These limits are the proposed EIRP limits for the different LPR frequency bands.
2. These limits are the general interference protection criteria for the different
frequency bands.
3. These numbers show the minimum main beam gain for a parabolic antenna
operating in accordance with the required antenna beamwidth (less than 8 degrees for
the 75-85 GHz band and less than 12 degrees for the lower frequency bands.)
5.
As illustrated in Table 2 above, when the LPR operates at maximum EIRP power with
the minimum main beam gain for a parabolic antenna, the side-lobe gain limit based on the relative gain
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specification varies from 1.7 dB below to 10.7 dB above the proposed fixed -10 dBi side-lobe antenna
gain limit. Therefore, in the 75-85 GHz band, the relative side-lobe gain is 1.7 dB less than an antenna
with a -10 dBi fixed side-lobe gain, while in the two lower frequency bands, the relative side-lobe gain
limit is 5.7 dB and 10.7 dB higher than an antenna with a -10 dBi fixed side-lobe gain. The difference
between the two limits will depend on the actual main beam gain of the antenna. Based on the examples
above, when the LPR is operated at the maximum proposed EIRP power limits, a fixed side-lobe gain
limit may result in side-lobe power which may be greater or less than the side-lobe limits shown in
column C in Table 2. Side-lobe power greater than the limit increases the interference potential and
side-lobe power less than the limit requires the side-lobe suppression to be more than necessary, making
the antenna design more challenging.
6.
These problems can be eliminated by specifying the antenna side-lobe gain limit relative
to the main-beam gain, instead of the proposed -10 dBi fixed side-lobe gain. If an antenna has a low
main-beam gain because of losses due to inefficiency and the input power to the antenna is increased to
compensate for the loss and to attain the maximum main beam EIRP, a side-lobe EIRP gain limit relative
to the main beam gain will ensure that side-lobe power is always suppressed to less than the general
emission limit of Section 15.209. This will maintain the existing interference protection criteria for
authorized radio services. The side-lobe gain limits relative to main-beam gain limits are illustrated in
Table 3 below.

Table 3 – Side-Lobe Gain Limit Relative to Main Beam Gain Limit

Frequency Range
Antenna Side lobe Gain
(GHz)
Relative to Main Beam Gain
(dB)
5.925-7.250
-22
24.05-29.00
-27
75-85
-38
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APPENDIX D

Final Rule Changes

For the reasons discussed in the preamble, the Federal Communications Commission amends title 47 of
the Code of Federal Regulations Part 15 to read as follows:

Part 15 – RADIO FREQUENCY DEVICES

1. The authority citation for Part 15 continues to read as follows:
Authority: 47 U.S.C. 154, 202, 303, 304, 307 and 544A.
2. Section 15.3 is amended by adding paragraph (ii) to read as follows:
§ 15.3 Definitions.
* * * * *
(ii) Level Probing Radar (LPR): A short-range radar transmitter used in a wide range of
applications to measure the amount of various substances, mostly liquids or granulates. LPR equipment
may operate in open-air environments or inside an enclosure containing the substance being measured.
* * * * *
3. Section 15.31 is amended by revising paragraphs (c) and (g) and adding paragraph (q) to read as
follows:
§ 15.31 Measurement standards.
* * * * *
(c) Except as otherwise indicated in § 15.256, for swept frequency equipment, measurements shall
be made with the frequency sweep stopped at those frequencies chosen for the measurements to be
reported.
* * * * *
(g) Equipment under test shall be positioned and adjusted, using those controls that are readily
accessible to or are intended to be accessible to the consumer, in such a manner as to maximize the level
of the emissions. For those devices to which wire leads may be attached by the operator, tests shall be
performed with wire leads attached. The wire leads shall be of the length to be used with the equipment if
that length is known. Otherwise, wire leads one meter in length shall be attached to the equipment.
Longer wire leads may be employed if necessary to interconnect to associated peripherals.
* * * * *
(q) As an alternative to § 15.256 of this part, a level probing radar (LPR) may be certified as an
intentional radiator by showing compliance with the general provisions for operation under Part 15
Subpart C of this chapter, provided that the device is tested in accordance with the provisions in either
39

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paragraphs (q)(1) or (q)(2) below. Compliance with the general provisions for an intentional radiator may
require compliance with other rules in this part, e.g., § 15.5, § 15.31, § 15.35, etc., when referenced.
(1) An LPR device intended for installation inside metal and concrete enclosures may show
compliance for radiated emissions when measured outside a representative enclosure with the LPR
installed inside, in accordance with the measurement guidelines established by the Commission for these
devices. LPR devices operating inside these types of enclosures shall ensure that the enclosure is closed
when the radar device is operating. Care shall be taken to ensure that gaskets, flanges, and other openings
are sealed to eliminate signal leakage outside of the structure. The responsible party shall take reasonable
steps to ensure that LPR devices intended for use in these types of enclosures shall not be installed in
open-air environments or inside enclosures with lower radio-frequency attenuating characteristics (e.g.,
fiberglass, plastic, etc.). An LPR device approved under this subsection may only be operated in the type
of enclosure for which it was approved.
(2) Except as provided in paragraph (q)(1) of this section, an LPR device shall be placed in testing
positions that ensure the field strength values of the radiated emissions are maximized, including in the
main beam of the LPR antenna.
* * * * *
4. Section 15.35 is amended by revising paragraphs (b) and (c) to read as follows:
§ 15.35 Measurement detector functions and bandwidths.
* * * * *
(b) Unless otherwise specified, on any frequency or frequencies above 1000 MHz, the radiated
emission limits are based on the use of measurement instrumentation employing an average detector
function. Unless otherwise specified, measurements above 1000 MHz shall be performed using a
minimum resolution bandwidth of 1 MHz. When average radiated emission measurements are specified
in this part, including average emission measurements below 1000 MHz, there also is a limit on the peak
level of the radio frequency emissions. Unless otherwise specified, e.g., see §§ 15.250, 15.252, 15.255,
15.256, and 15.509-15.519 of this part, the limit on peak radio frequency emissions is 20 dB above the
maximum permitted average emission limit applicable to the equipment under test. This peak limit
applies to the total peak emission level radiated by the device, e.g., the total peak power level. Note that
the use of a pulse desensitization correction factor may be needed to determine the total peak emission
level. The instruction manual or application note for the measurement instrument should be consulted for
determining pulse desensitization factors, as necessary.
(c) Unless otherwise specified, e.g., Section 15.255(b), and Section 15.256(l)(5), when the radiated
emission limits are expressed in terms of the average value of the emission, and pulsed operation is
employed, the measurement field strength shall be determined by averaging over one complete pulse
train, including blanking intervals, as long as the pulse train does not exceed 0.1 seconds. As an
alternative (provided the transmitter operates for longer than 0.1 seconds) or in cases where the pulse train
exceeds 0.1 seconds, the measured field strength shall be determined from the average absolute voltage
during a 0.1 second interval during which the field strength is at its maximum value. The exact method of
calculating the average field strength shall be submitted with any application for certification or shall be
retained in the measurement data file for equipment subject to notification or verification.
* * * * *
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5. Section 15.205 is amended by revising paragraph (d)(4) to read as follows:
§ 15.205 Restricted bands of operation.
* * * * *
(d) * * *
* * * * *
(4) Any equipment operated under the provisions of § 15.253, § 15.255, § 15.256 in the frequency band
75-85 GHz, or § 15.257 of this part.
* * * * *
6. New Section 15.256 is added to read as follows:
§ 15.256 Operation of level probing radars within the bands 5.925-7.250 GHz, 24.05-29.00 GHz, and
75-85 GHz.
(a)
Operation under this section is limited to level probing radar (LPR) devices.
(b)
LPR devices operating under the provisions of this section shall utilize a dedicated or integrated
transmit antenna, and the system shall be installed and maintained to ensure a vertically downward
orientation of the transmit antenna’s main beam.
(c)
LPR devices operating under the provisions of this section shall be installed only at fixed
locations. The LPR device shall not operate while being moved, or while inside a moving container.
(d)
Hand-held applications are prohibited.
(e)
Marketing to residential consumers is prohibited.
(f)
The fundamental bandwidth of an LPR emission is defined as the width of the signal between two
points, one below and one above the center frequency, outside of which all emissions are attenuated by at
least 10 dB relative to the maximum transmitter output power when measured in an equivalent resolution
bandwidth.
(1) The minimum fundamental emission bandwidth shall be 50 MHz for LPR operation under the
provisions of this section.
(2) LPR devices operating under this section must confine their fundamental emission bandwidth
within the 5.925-7.250 GHz, 24.05-29.00 GHz, and 75-85 GHz bands under all conditions of
operation.
(g)
Fundamental Emissions Limits
(1) All emission limits provided in this section are expressed in terms of Equivalent Isotropic
Radiated Power (EIRP).
(2) The EIRP level is to be determined from the maximum measured power within a specified
bandwidth.
(i) The EIRP in 1 MHz is computed from the maximum power level measured within
any 1-MHz bandwidth using a power averaging detector;
(ii) The EIRP in 50 MHz is computed from the maximum power level measured with a
peak detector in a 50-MHz bandwidth centered on the frequency at which the
maximum average power level is realized and this 50 MHz bandwidth must be
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contained within the authorized operating bandwidth. For a RBW less than 50 MHz,
the peak EIRP limit (in dBm) is reduced by 20 log(RBW/50) dB where RBW is the
resolution bandwidth in megahertz. The RBW shall not be lower than 1 MHz or
greater than 50 MHz. The video bandwidth of the measurement instrument shall not
be less than the RBW. If the RBW is greater than 3 MHz, the application for
certification filed shall contain a detailed description of the test procedure, calibration
of the test setup, and the instrumentation employed in the testing.
(3) The EIRP limits for LPR operations in the bands authorized by this rule section are provided
in Table 1 below:

Frequency Band of

Average Emission Limit

Peak Emission Limit (EIRP

Operation (GHz)

(EIRP in dBm measured
in dBm measured in
in 1 MHz)
50 MHz)
5.925-7.250
-33
7
24.05-29.00
-14
26
75-85
-3
34
Table 1 – LPR EIRP emission limits
The emission limits in Table 1 are based on boresight measurements (i.e., measurements performed
within the main beam of an LPR antenna).
(h)
Unwanted Emissions Limits
Unwanted emissions from LPR devices shall not exceed the general emission limit in § 15.209 of
this chapter.
(i)
Antenna Beamwidth
(1) LPR devices operating under the provisions of this section within the 5.925-7.250 GHz and
24.05-29.00 GHz bands must use an antenna with a -3 dB beamwidth no greater than
12 degrees.
(2) LPR devices operating under the provisions of this section within the 75-85 GHz band must
use an antenna with a -3 dB beamwidth no greater than 8 degrees.
(j)
Antenna Side Lobe Gain
LPR devices operating under the provisions of this section must limit the side lobe antenna gain
relative to the main beam gain for off-axis angles from the main beam of greater than 60 degrees
to the levels provided in Table 2 below:
Antenna Side Lobe
Frequency Range
Gain Limit Relative to
(GHz)
Main Beam Gain
(dB)
5.925-7.250
-22
24.05-29.00
-27
75-85
-38
Table 2 – Antenna side lobe gain limits
(k)
Emissions from digital circuitry used to enable the operation of the transmitter may comply with
the limits in § 15.209 of this chapter provided it can be clearly demonstrated that those emissions are due
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solely to emissions from digital circuitry contained within the transmitter and the emissions are not
intended to be radiated from the transmitter’s antenna. Emissions from associated digital devices, as
defined in § 15.3(k) of this chapter, e.g., emissions from digital circuitry used to control additional
functions or capabilities other than the operation of the transmitter, are subject to the limits contained in
Subpart B of Part 15 of this chapter. Emissions from these digital circuits shall not be employed in
determining the -10 dB bandwidth of the fundamental emission or the frequency at which the highest
emission level occurs.
(l)
Measurement Procedures
(1) Radiated measurements of the fundamental emission bandwidth and power shall be made
with maximum main-beam coupling between the LPR and test antennas (boresight).
(2) Measurements of the unwanted emissions radiating from an LPR shall be made utilizing
elevation and azimuth scans to determine the location at which the emissions are maximized.
(3) All emissions at and below 1000 MHz except 9-90 kHz and 110-490 kHz bands are based on
measurements employing a CISPR quasi-peak detector.
(4) The fundamental emission bandwidth measurement shall be made using a peak detector with
a resolution bandwidth of 1 MHz and a video bandwidth of at least 3 MHz.
(5) The provisions in §§ 15.35(b) and (c) of this part that require emissions to be averaged over a
100 millisecond period and that limits the peak power to 20 dB above the average limit do not
apply to devices operating under paragraphs (a)-(l) of this section.
(6) Compliance measurements for minimum emission bandwidth of frequency-agile LPR devices
shall be performed with any related frequency sweep, step, or hop function activated.
(7) Compliance measurements shall be made in accordance with the specific procedures
published or otherwise authorized by the Commission.
43

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