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Rule Part

47 C.F.R, Part 30

Radio Service Code(s)

  • UU - Upper Microwave Flexible Use Service (UMFUS) millimeter frequency bands
    • 24.25 - 24.5 GHz (24 GHz band)
    • 24.75 - 25.25 GHz (24 GHz band)
    • 27.5 - 28.35 GHz (28 GHz band)
    • 37.0 - 37.6 GHz (Lower 37 GHz band)
    • 37.6 - 38.6 GHz (Upper 37 GHz band)
    • 38.6 - 40.0 GHz (39 GHz band)
    • 47.2 - 48.2 GHz (47 GHz band)


Upper Microwave Flexible Use Service (UMFUS) is the collective term the FCC uses for innovative fixed, temporary fixed, mobile and Internet of Things (IoT) terrestrial wireless services using bandwidth that is sufficient for the provision of a variety of applications, including those using voice and data (such as Internet browsing, message services, and full-motion video) content. The services provided by UMFUS licensees are limited only by the Fixed, Mobile, and co-primary Fixed Satellite Service (FSS) and Federal use designation of the spectrum we allocate for UMFUS, and the services rules we adopted for those specific frequency bands.

The Commission has designated several different UMFUS spectrum bands in recent years. The following contains a general description of the individual UMFUS bands based on recent actions the Commission has taken for establishing the Part 30 rules to license these bands. The descriptions contain links to pages with more detailed information about each band, including historical information.

Historically, mobile wireless services have been targeted at bands below 3 GHz due to technological and practical limitations.  However, there have been significant developments in antenna and processing technologies that may allow the use of higher frequencies – in this case those above 24 GHz – for mobile applications.  Studies show that these new technologies can ultimately facilitate dramatically faster wireless broadband speeds and lower latencies than those available today. 



  • Notice of Inquiry: On October 17, 2014, the Commission released a Notice of Inquiry that sought to broaden its understanding of the state of the art in technological developments for using frequencies above 24 GHz for mobile and other uses.
  • Notice of Proposed Rulemaking: On October 22, 2015, the Commission adopted a Notice of Proposed Rulemaking, which built on the record developed by the Notice of Inquiry. The Notice of Proposed Rulemaking proposed a mix of licensed and unlicensed bands, with a licensing framework that supports flexible use of the spectrum and creates opportunities for sharing among different kinds of users and use cases.
  • First Report and Order: On July 14, 2016, the Commission adopted a Report and Order and Further Notice of Proposed Rulemaking.
    • The First Report and Order created new fixed and mobile licenses in three bands: 27.5-28.35 GHz (28 GHz band), 38.6-40 GHz (39 GHz band), and 37-38.6 GHz band (37 GHz band).It named the new service in these bands the Upper Microwave Flexible Use Service (UMFUS).
    • The First Report and Order granted incumbent licensees in the 28 GHz and 39 GHz bands new mobile rights.New licenses not held by incumbents were designated to be auctioned in these bands, along with 1000 megahertz of the 37 GHz band. New licenses not held by 28 GHz incumbents were offered in Auction 101; new licenses not held by 39 GHz incumbents will be offered in an incentive auction (Auction 103).
      • In the 37 GHz band, the Report and Order adopted a band plan that allows for continuity of commercial operations between the 37 and 39 GHz bands, while protecting federal uses and creating a path for their future use.  It protected a limited number of Federal military sites across the full 37 GHz band and maintained the existing Federal fixed and mobile allocations throughout the band.  In the 37-37.6 GHz band, the Report and Order created a space for coordinated co-primary shared access between Federal and non-Federal users.
    • The First Report and Order adopted mechanisms to protect incumbent FSS operations in some areas and provided multiple paths for current and future FSS operations in 28 GHz to gain protection and expand operations in a manner consistent with terrestrial systems.
    • The First Report and Order adopted a variety of other service and technical rules to facilitate the use of these bands.
    • To meet the Commission’s statutory duty to ensure that spectrum is being placed in use, the First Report and Order adopted performance requirements that are flexible to allow multiple use cases to evolve over time.
    • In addition to creating rules for licensed services, the First Report and Order also established a new unlicensed band at 64-71 GHz, making a 14 gigahertz unlicensed band from 57-71 GHz.
  • The FNPRM sought comment, among other things, on:
    • authorizing fixed and mobile use in the 31.8-33 GHz (32 GHz band), 42-42.5 GHz (42 GHz band), 50.4-52.6 GHz (50 GHz band).
    • developing the sharing framework for the 37-37.6 GHz band, both among non-Federal operators and with the Federal government.
    • circumstances under which Federal government users can gain coordinated access to spectrum in the 37.6-38.6 GHz band (in addition to the protected sites) in the future.  


  • Second Report and Order: On November 22, 2017, the Commission adopted a Second Report and Order, Second Further Notice of Proposed Rulemaking, Order on Reconsideration, and Memorandum Opinion and Order.
    • The Second Report and Order created new Upper Microwave Flexible Use Service rules for the 24.25-24.45 GHz and 24.75-25.25 GHz (collectively, 24 GHz band - See Auction 102) and the 47.2-48.2 GHz band (47 GHz band - See Auction 103). The Commission applied the existing UMFUS technical and service rules to those bands.
    • The Second Report and Order declined to adopt any limits on the amount of spectrum in the 24 GHz and 47 GHz bands an entity may acquire through competitive bidding at auction.The item also increased the threshold for mmW transactions that may warrant further competitive analysis to a combined 1850 megahertz for all mmW bands.
    • The Second Report and Order adopted rules to allow unlicensed operation onboard most aircraft in the 57-71 GHz band under Part 15 of our rules.
    • On reconsideration, the Commission modified and clarified the rules for sharing between UMFUS and Fixed-Satellite Service earth stations in order to encourage placement of earth stations in smaller markets without harming terrestrial operations.
    • The Commission decided to keep 40-42 GHz and 48.2-50.2 GHz as core satellite bands in order to encourage the deployment of advanced satellite broadband systems.Conversely, it declined to relax restrictions on satellite use of the 37.5-40 GHz UMFUS band.


  • Third Report and Order: On June 7, 2018, the Commission adopted a Third Report and Order, Memorandum Opinion and Order, and Third Further Notice of Proposed Rulemaking. The Third Report and Order takes the following actions: 
    • Adopted a geographic area metric for Upper Microwave Flexible Use Service licenses, to be included in the existing list of performance metrics choices, as an option potentially suitable to IoT-type deployments;
    • Adopted a sharing framework to allow use of the 24.75-25.25 GHz band for terrestrial wireless operations and for Fixed Satellite Service (FSS) earth stations;
    • Adopted 100 megahertz channels for the 37-37.6 GHz band (Lower 37 GHz band); and
  • The MO&O denied petitions for reconsideration asking for geographic area licensing in the Lower 37 GHz band and asking to allocate the 42 GHz band for satellite use.
  • Finally, the FNPRM sought comment on:
    • How the 42 GHz band could be used to provide commercial wireless broadband service including possible opportunities for unlicensed and/or shared use, pursuant to the MOBILE NOW Act;
    • Coordination mechanisms to facilitate shared use of the Lower 37 GHz band between Federal and non-Federal users, and among non-Federal users;
    • Making the 25.25-27.5 GHz band (26 GHz band) available for flexible fixed and mobile use; and
    • FSS use of the 50.4-51.4 GHz band for a limited number of earth stations.


  • Fourth Report and Order:; On December 12, 2018, the Commission adopted a Fourth Report and Order (following a Fourth Notice of Proposed Rulemaking), which:
    • Modified the band plans for the Upper 37 GHz, 39 GHz, and 47 GHz bands from 200 megahertz blocks to 100 megahertz blocks to be licensed by Partial Economic Area (PEA), which will facilitate the simultaneous auction of licenses in the three bands;
    • Adopted an incentive auction mechanism that would offer contiguous blocks of spectrum that conform to the newly adopted band plan and service rules throughout the Upper 37 GHz, 39 GHz, and 47 GHz bands (see Auction 103), while preserving the existing spectrum usage rights of incumbents as much as possible.
    • An incumbent may choose to: (1) retain its licenses but have them modified based on a proposal from the Commission; (2) have its licenses modified based on its own alternative proposal that satisfies specified conditions; or (3) relinquish its licenses in exchange for an incentive payment and/or the ability to bid for new licenses in the incentive auction.
    • The incentive auction will have two phases: a clock phase in which bidders bid on generic license blocks; and an assignment phase in which clock phase winners bid on specific frequencies.
      • Each incumbent choosing to relinquish its licenses will be offered an incentive payment equal to the auction’s final clock price for equivalent licenses in the same PEA.
      • New entrants and participating incumbents may bid for new licenses, but incumbents relinquishing their licenses do not have to bid for new licenses.
      • Incumbents that choose to bid for new licenses may rebid on spectrum blocks equivalent to their existing holdings but do not have to do so, unless they want to continue to hold licenses in those areas.Participating incumbents can apply their incentive payments toward payments for any new licenses.


  • Fifth Report and Order: On April 12, 2019, the Commission adopted a Fifth Report and Order that takes the following actions:
    • Establishes rules to allow Fixed-Satellite Service (FSS) operators such as satellite broadband service operators, to operate with individually licensed earth stations transmitting in the 50.4–51.4 GHz band using criteria identical to those applicable in the 24.75–25.25 GHz band. 
    • Establishes a small coordination zone in the 37 GHz band around Edwards Air Force Base, California.   In addition, the Fifth Report and Order converts four overlapping coordination zones currently listed in the Table under the China Lake, California site into one zone.
    • Establishes a process for the Department of Defense to operate on a shared basis in the Upper 37 GHz band (37.6–38.6 GHz band) in limited circumstances.
      • The Department may submit requests for access to the Upper 37 GHz band for specific additional military bases and ranges, for the purpose of defense applications or national security;
      • Such requests must include a justification regarding why the proposed operations could not be accommodated in the Lower 37 GHz band;
      • FCC staff will review the request to assess any potential impact on non-Federal licensees, contacting the potentially affected licensees and facilitating direct coordination with the Department and NTIA (including establishing a mechanism for appropriate notice to prospective future successors-in-interest to the affected licensees).
      • The FCC will determine whether the request for access can be accommodated without creating a significant risk of harmful interference to current or planned deployments by potentially affected non-Federal licensees. 



Market Areas and Channel Blocks

UMFUS licenses are issued by market areas and channel blocks.

The market areas for UMFUS licenses are:

  • 28 GHz - Counties (based on 1990 US Census County Boundaries) – There are 3,232 Counties
  • 24 GHz band, Upper 37 GHz, 39 GHz, 47 GHz - Partial Economic Area (PEA) – There are 416 PEAs

Channel blocks are groups of frequencies. For the specific channel blocks associated with a particular UMFUS band, please see § 30.4 (Frequencies) and § 30.5 (Service areas).


The FCC typically uses an auctions process, absent a need to do otherwise, to assign initial licenses for UMFUS from among mutually exclusive applications. Access to UMFUS spectrum may also be attained through the secondary market, which generally allows UMFUS licensees to transfer, sell or lease spectrum, in whole or in part.

Existing licensees in the 27.5 – 28.35 GHz band and 38.6 – 40.0 GHz band were converted to UMFUS licenses and granted rights to provide mobile services.  Information about UMFUS licenses can be found in the Universal Licensing System (ULS).  The ULS radio service code and description for UMFUS is UU. 

Auctions have been conducted or will be conducted in the 28 GHz, 24 GHz, upper 37 GHz, 39 GHz, and 47 GHz UMFUS spectrum bands.  See Auction 101, 102, 103.   In conjunction with auction 103, WTB and OEA implemented procedures to reconfigure the 39 GHz band in preparation for the incentive auction.  (See Fourth Report and Order, Initial 39 GHz Reconfiguration Procedures and Order of Modification Public Notice)

The FCC service rules for UMFUS are located in 47 C.F.R. Part 30. 



FCC Takes Steps to Make Millimeter Wave Spectrum Available for 5G
Fifth Report and Order
PDF | Word

Initial 39 GHz Reconfiguration Procedures and Order of Modification
Public Notice: PDF | Word



FCC Adopts Innovative Incentive Auction For 5G High-band Spectrum
Fourth Report and Order
PDF | Word

Use of Spectrum Bands Above 24 GHz for Mobile Radio Services
Compliance Guide: PDF | Word

FCC Proposes Steps Towards Auction of 37 GHz, 39 GHz, and 47 GHz Bands
Forth Further Notice of Proposed Rule Making
News Release

39 GHz Voluntary Rebanding Public Notice
PDF | Word

FCC Takes Next Steps to Open Spectrum Frontiers for 5G Connectivity
Third Report and Order, FNPRM, Memorandum Opinion and Order
News Release

ULS UMFUS Incumbent License Conversion Public Notice
PDF | Word



FCC Takes Next Steps on Facilitating Spectrum Frontiers Spectrum
Second Report and Order, Order on Reconsideration, FNPRM, Memorandum Opinion and Order
News Release



Erratum - Use of Spectrum Bands Above 24 GHz for Mobile Radio Services
PDF | Word

FCC Adopts Rules to Facilitate Next Generation Wireless Technologies
First Report and Order, FNPRM
News Release



FCC Promotes Higher Frequency Spectrum for Future Wireless Technology
Notice of Proposed Rulemaking



NOI to examine use of bands above 24 GHz for mobile broadband
Notice of Inquiry
News Release

Monday, August 15, 2022