The term “millimeter wave” derives from the wavelength of radio signals on frequencies between 30 GHz and 300 GHz, which ranges between 1 and 10 millimeters.
At these frequencies, radio signals attenuate more rapidly with distance than at other frequencies and antennas that can narrowly focus transmitted energy are practical and of modest size. While the limited range of such transmissions might appear to be a major disadvantage for many applications, it does allow the reuse of frequencies within very short distances and, thereby enables a higher concentration of transmitters to be located in a geographical area than is possible at lower frequencies.
Because of shorter wavelengths, the 71-76 GHz, 81-86 GHz, and 92-95 GHz (70/80/90 GHz) bands permit the use of smaller antennas, than would be required for similar circumstances in the lower bands, to achieve the same high directivity and high gain. The immediate consequence of this high directivity, coupled with the high free space loss at these frequencies, is the possibility of a more efficient use of the spectrum for point-to-multipoint applications. Since a greater number of high directive antennas can be placed than less directive antennas in a given area, the net result is higher reuse of the spectrum, and higher density of users, as compared to lower frequencies. Furthermore, due to the fact that one can place more voice channels or broadband information using a higher frequency to transmit the information, this spectrum could potentially be used as a replacement for or supplement to fiber optics.
On October 16, 2003, the Commission adopted a Report and Order establishing service rules to promote non-Federal Government development and use of the “millimeter wave” spectrum in the 70/80/90 GHz bands on a shared basis with Federal Government operations, and subsequently modified the Report and Order with a Memorandum Opinion and Order (FCC 05-45) (pdf). The Commission adopted a flexible and innovative regulatory framework for the 70/80/90 GHz bands, allowing links to be registered with third party database managers after they are issued a geographic nationwide license by the Commission.
Details of the licensing, link registration, and interference protection are explained in the Report and Order (FCC-03-248), Public Notice DA-04-1493, and the Memorandum Opinion and Order (FCC-05-45).
In 2016, in the context of the Commission's spectrum frontiers proceeding, the 71-76 GHz and 81-86 GHz bands were considered as a potential candidate for mobile services. See GN Docket No. 14-177.
In 2017 the Commission found broad support in the record of the spectrum frontiers proceedings for focusing on and enhancing the existing rules for fixed use of the 71-76 GHz and 81-86 GHz bands, but little consensus among the proponents of mobile use as to how to coexist with fixed links. The Commission also found that, under the existing licensing mechanism, these bands can play an important role in 5G development by facilitating backhaul and other fixed uses. The Commission stated that it is important not only to protect existing links but also to provide an opportunity for future growth of fixed service in these bands as demand for backhaul and other related services increases. The Commission also noted that several proposals are pending to modify the existing rules for these bands and reserved the right to revisit this issue as mobile use deploys in other millimeter wave bands, technology develops, and as further thought is given to mobile/fixed coexistence. See GN Docket No. 14-177 for more information.
In June 2020, the Commission adopted a Notice of Proposed Rulemaking seeking comment on potential rule changes, proposed by interested parties, for non-Federal uses of the 70/80/90 GHz bands. See Modernizing and Expanding Access to the 70/80/90 GHz Bands, WT Docket No. 20-133, Notice of Proposed Rulemaking, 35 FCC Rcd 6039 (2020) (70/80/90 GHz NPRM). Certain of the proposals in the 70/80/90 GHz NPRM, such as changes to antenna standards and link registration processes, were aimed at improving efficiency in traditional uses of the bands, such as wireless backhaul. Other inquiries contemplated use of the bands for new service offerings, such as Aeronet Global Communications, Inc.’s (Aeronet) proposals that the Commission authorize point-to-point links to endpoints in motion to facilitate broadband service to ships and aircraft, provided that they do not cause interference to other authorized uses. The Commission also sought comment on whether the 70/80/90 GHz bands could accommodate other types of services, such as High Altitude Platform Stations (HAPS) or similar services.
In October 2021, the Wireless Telecommunications Bureau released a Public Notice seeking to supplement the record in the ongoing rulemaking on the 70/80/90 GHz bands. In particular, the Commission sought comment on whether HAPS or other stratospheric-based platform services could be deployed in the 70/80/90 GHz bands to provide broadband Internet access to consumers and communities that may otherwise lack robust, consistent connectivity. The Commission also sought additional information regarding the potential use of these bands to provide broadband Internet access to customers on airplanes and aboard ships, as proposed by Aeronet.
The Commission adopted a flexible and innovative licensing framework for the 70/80/90 GHz bands that does not require separate FCC license applications for most links or traditional frequency coordination among non-Federal Government users. Rights with regard to specific links are established based upon the date and time of link registration.
A license (FCC authority) to operate a link in the Millimeter Wave 70-80-90 GHz Radio Service consists of two parts: (1) a non-exclusive nationwide license (see below), combined with (2) registration of each link (see link registration tab).
The non-exclusive nationwide license does not authorize operation until the link is registered as an approved link in the Link Registration System administered by third party database managers (see link registration tab).
Nonexclusive Nationwide License
The nationwide license serves as a prerequisite for registering individual point-to-point links.
A licensee is not authorized to operate a 70/80/90 GHz link unless/until the link is registered as an approved link in the Link Registration System administered by third-party Database Managers.
Because the 70/80/90 GHz bands are allocated on a shared basis with Federal Government users, each link must be coordinated with the National Telecommunications and Information Administration (NTIA) with respect to Federal Government operations as part of the registration process (see link registration tab).
Applicants for non-exclusive nationwide licenses will be required to file FCC Form 601 Main Form and Schedule B. Because the non-exclusive nationwide license serves as a prerequisite for registering links, an applicant will initially receive a single license for all available frequency bands (71-76, 81-86, 92- 94.0, and 94.1 - 95 GHz).
Notice to Common Carriers
EXAMPLE: On June 30, 2004, the Bureau releases the weekly Public Notice of applications filed between June 21-25, 2004, that are acceptable for filing. The 31st day following this public notice is Saturday, July 31, 2004, making Monday, August 2, 2004, the first day on which a common carrier application can be granted. A license is required to file link registrations. Given that July 19, 2004, is the starting date for filing link registrations, and that no common carrier licenses can be granted prior to August 2, 2004, applicants seeking to operate under more than one regulatory status may wish to file one application for common carrier regulatory status and a second application for non-common carrier and/or private, internal regulatory status, as applicable.
The non-exclusive nationwide license (see licensing tab) is a required prerequisite for registering individual links in the 71-76 GHz, 81-86 GHz, and 92-95 GHz (70/80/90 GHz) bands. Individual links cannot be registered until a non-exclusive nationwide license is obtained.
Licensees must register links through one of the approved Third Party Database Managers (see below). In a few special circumstances an application must also be filed in ULS (e.g., if the link has received a “yellow light” response from NTIA, requires environmental assessment; requires coordination because of a quiet zone; or is subject to international coordination requirements). Licensees may contact any of the Database Managers for more information about link registration and each Database Manager provides public access online to link registration data.
The interference protection afforded to a link is based on the date and time that a licensee submits a link registration (new or modified) to a third-party database manager with an electronic copy of an interference analysis that demonstrates that the potential for harmful interference to or from all previously registered non-government links has been analyzed according to the standards of the FCC rule section 101.105 and generally accepted good engineering practice, and that the proposed link will neither cause harmful interference to, nor receive harmful interference from, any previously registered non-government link.
Further information about registering links is provided in Public Notice DA 05-311 (pdf).
Third Party Database Managers