SpectrumWiki

Radio spectrum allocations

Look up a frequency or a range.

Examples: 88.5 MHz, 1350–1430 MHz, 2.4 GHz

311.999999 MHz (311,999,999 Hz)

U.S. Non-Federal-Government Allocations

267 – 322 MHz

U.S. Federal Government Allocations

267 – 322 MHz

FIXED

MOBILE

G27 G100

ITU Region 1 Allocations

273 – 312 MHz

FIXED

MOBILE

5.254

ITU Region 2 Allocations

273 – 312 MHz

FIXED

MOBILE

5.254

ITU Region 3 Allocations

273 – 312 MHz

FIXED

MOBILE

5.254

Footnotes

  • 5.254   The bands 235-322 MHz and 335.4-399.9 MHz may be used by the mobile-satellite service, subject to agreement obtained under No. 9.21, on condition that stations in this service do not cause harmful interference to those of other services operating or planned to be operated in accordance with the Table of Frequency Allocations except for the additional allocation made in footnote No. 5.256A. (WRC-03)

  • G27   In the bands 225-328.6 MHz, 335.4-399.9 MHz, and 1350-1390 MHz, the fixed and mobile services are limited to the military services.

  • G100   The bands 235-322 MHz and 335.4-399.9 MHz are also allocated on a primary basis to the mobile-satellite service, limited to military operations.

Wiki entries

Area Common User System (ACUS) (NTIA)

Current Use
225–328.6 MHz Military land mobile communications 225–328.6 MHz Military fixed point-to-point communications
The military agencies use the band 225-328.6 MHz for tactical and non-tactical land mobile and fixed service point-to-point communications. The most extensive use is by the Army's Area Common User System (ACUS), consisting of both land mobile and fixed communications systems. The mobile version uses mobile subscriber equipment (MSE) that functions like a cellular communications network, capable of providing communications to many users.

The fixed communications part of the ACUS is a high capacity line-of-sight point-to-point radio system. The radio provides voice and data communications over paths up to 70 miles. The system can use various data rates, with the highest being 34 Mbps, and it has a feature that provides a spectrum scan to detect spectrum congestion to identify frequencies to maximize link availability.

In general, the band 225-328.6 MHz is reserved for military uses by North Atlantic Treaty Organization (NATO), its member nations, and other U.S. allies. The band is harmonized among NATO-member nations for secure communications.

(Information extracted from the NTIA Federal Government Spectrum Use Reports, dated December 1, 2015)

Federal Maritime Mobile Communications (NTIA)

Current Use
225–328.6 MHz Federal Ship-to-Shore and Ship-to-Ship Communications
The Navy, Coast Guard, and NASA use the band 225-328.6 MHz for tactical and non-tactical operations such as ship-to-air-to-ship and ship-to-ship for clear and secure voice communications. The Coast Guard also uses the band for a secure data communications link.

In general, the band 225-328.6 MHz is reserved for military uses by North Atlantic Treaty Organization (NATO), its member nations, and other U.S. allies. The band is harmonized among NATO-member nations for secure communications.

(Information extracted from the NTIA Federal Government Spectrum Use Reports, dated December 1, 2015)

Military Aeronautical/ATC Communications and Telemetry (NTIA)

Current Use
225–328.6 MHz Military aeronautical communications and telemetry
The military agencies, National Guard units, the Coast Guard, and the FAA are the heaviest users of the band 225-328.6 MHz, using the band for critical air-to-ground-to-air communications systems. The military agencies and National Guard units use the band 225-328.6 MHz for various types of aeronautical communications, e.g., for training flights and air-traffic-control functions such as ground control, approach control, enroute aircraft separation, and in-flight refueling services. The Air Force, Army, Navy, and the FAA have thousands of frequency assignments for air-to-ground-to-air communications in the band 225-328.6 MHz. Most of these assignments are to ground stations.

The Coast Guard uses the band on its maritime search-and-rescue aircraft and other aircraft for air-to-ground-to-air communications. The military agencies, National Guard units, and the FAA make extensive use of the band 225-328.6 MHz which alleviates possible impact of the national airspace civilian air-to-ground-to-air communications operating in the bands within 117.975-137 MHz. Thus, the Federal use of the band 225-328.6 MHz for aeronautical communications plays an important part in national defense and security, and to control the nation's airspace.

The band 225-328.6 MHz is also used for essential communications by a number of other agencies such as NASA, DOE, and DOC. NASA uses the band for aircraft communications, and for International Space Station (ISS) communications during Extravehicular Activity (EVA); and DOC uses the band on National Oceanographic and Atmospheric Administration (NOAA) hurricane-hunter aircraft, and on ground stations to communicate with other hurricane-hunter aircraft.

The military agencies use the band 225-328.6 MHz for a major tactical communications system to provide anti-jam, secure, frequency-hopping radio communications for tactical air-to-air and air-to-ground-to-air communications. The uses include coordination and vectoring of aircraft to targets, and large scale training exercises.

For example, the major radio communications systems are deployed on all rotary wing aircraft, and are used by all operational aviation units, air traffic services, and units. The radio communications system enables interoperability communications among Air Force, Navy, Army, and NATO units.

The Navy makes extensive use of the band for aeronautical telemetry, and DOE also uses the band for this purpose. The Navy uses the band for flight testing of military aircraft. The military agencies also use this band for telemetry systems for rocket testing.

In generall, the band 225-328.6 MHz is reserved for military uses by North Atlantic Treaty Organization (NATO), its member nations, and other U.S. allies. The band is harmonized among NATO-member nations for secure communications.

(Information extracted from the NTIA Federal Government Spectrum Use Reports, dated December 1, 2015)

Military Battle Simulation Systems (NTIA)

Current Use
225–328.6 MHz Military battle simulation systems
The military agencies use the band for research, development, testing, and evaluation of various types of communications and sensing systems. The military agencies operate training center instrumentation systems in this band for data links connecting battle simulation systems on participants' platforms (airborne, shipborne, or surface) to central processing facilities.

In general, the band 225-328.6 MHz is reserved for military uses by North Atlantic Treaty Organization (NATO), its member nations, and other U.S. allies. The band is harmonized among NATO-member nations for secure communications.

(Information extracted from the NTIA Federal Government Spectrum Use Reports, dated December 1, 2015)

Military Mobile-Satellite Communications (NTIA)

Current Use
225–322 MHz Military mobile-satellite communications
Satellites operating in the mobile-satellite service in this band are used by the military services and the Coast Guard. The military mobile-satellite communications networks in the band serve ships at sea, aircraft, land-based forces, and a variety of other U.S. military fixed and mobile terminals used by mobile users. The bands 225-322 MHz and 335.4- 399.9 MHz are the only bands below 7250 MHz available for Federal Government mobile-satellite communications, and the narrowband satellite links are frequently the only reliable means of communications.

The military makes extensive use of the mobile-satellite service operating in this band because the electromagnetic waves can penetrate foliage, inclement weather, and urban terrain including concrete-reinforced buildings. Small antennas can be used at the earth terminals making it easy to transport the stations. There are numerous satellite earth terminals currently in use by the military, many of which are small and portable enough to be carried deep into theaters of operation.

The Federal use of the band for mobile satellites was initiated in 1978 with the Navy's Fleet Satellite Communications System (FLTSATCOM), a constellation of five geostationary satellites operating in the band 235-322 MHz, channelized into the downlinks at 243.855-269.95 MHz and corresponding uplinks in the band 292.85- 317.325 MHz. The Navy began upgrading the FLTSATCOM in the 1990s with the UHF Follow-On (UFO) satellites. The UFO satellites offer increased communications channel capacity over the same frequency spectrum used by the previous FLTSATCOM systems. Each UFO satellite has 39 channels with a total 555 kHz bandwidth. The satellite payload comprises 21 narrowband channels at 5 kHz each and 17 relay channels at 25 kHz.3 These channels are used by the military agencies for tactical communications on land, ships, submarines, and aircraft. The Coast Guard also uses channels on the military satellites on some of their ships.

The Department of Defense (DOD) Defense Satellite Communications System (DSCS-III) series of geostationary satellites operating in the 7- and 8- GHz bands also carry a transponder in this band called the single channel transponder (SCT) that provides communications for emergency action messages to the forces. The Military, Strategic, and Tactical Relay Satellite (MILSTAR) geostationary satellite also has mobile-satellite capability in this band, with a transponder that provides four Air Force Satellite Communications (AFSATCOM IIR) channels and a fleet broadcast channel.

The Navy has launched the next generation mobile satellites, termed the Multiple User Objective System (MUOS) that use the bands 243.525-270.05 MHz and 280-320 MHz. The MUOS is undergoing testing and is not fully operational as of September, 2014. The Navy has awarded contracts for the MUOS, and overall, the MUOS will be $6.4 billion system. The MUOS enables communications to various terminal devices such as handhelds, laptops, and personal communications units. To support legacy systems, the MUOS will use a narrowband system of 64 kbps/channel and below. The MUOS will use wideband-code-division-multiple-access (WCDMA) technology, the same technology as some forms of the third generation (3G) commercial cellphone technology. The capacity is 4 Mbps per antenna beam.

In general, the band 225-328.6 MHz is reserved for military uses by North Atlantic Treaty Organization (NATO), its member nations, and other U.S. allies. The band is harmonized among NATO-member nations for secure communications.

(Information extracted from the NTIA Federal Government Spectrum Use Reports, dated December 1, 2015)

UHF Follow-On (UFO) Satellite Constellation

Current Use
292–317 MHz UFO service uplink
UFO is a narrowband satellite communications system belonging to the U.S. military. The first UFO satellite was launched in September 1993, and the tenth was launched in December 2003. Presently eight of the satellites remain functional, and the constellation is passing its expected lifetime. MUOS (see separate wiki entry) is the UFO replacement. All UFO satellites are in geostationary orbit. Each satellite provides 21 5-kHz channels and 17 25-kHz channels.

Mobile User Objective System (MUOS)

Current Use
300–320 MHz MUOS service uplink
According to the U.S. Navy:

Mobile User Object System (MUOS) is a narrowband Military Satellite Communications (MILSATCOM) system that supports a worldwide, multi-Service population of mobile and fixed-site terminal users in the Ultra High Frequency (UHF) band, providing increased communications capabilities to smaller terminals while still supporting interoperability to legacy terminals.

MUOS adapts a commercial third generation Wideband Code Division Multiple Access (WCDMA) cellular phone network architecture and combines it with geosynchronous satellites (in place of cell towers) to provide a new and more capable UHF MILSATCOM system. The constellation of four operational satellites and ground network control will provide greater than 10 times the system capacity of the current UHF Follow-On (UFO) constellation.

The first MUOS satellite was launched February 24th, 2012, and began operations in August 2012. The MUOS constellation will eventually be comprised of four GSO satellites and one in-orbit spare. The operational satellites will be located at 177 deg W (Pacific), 100 deg W (CONUS), 15.5 deg W (Atlantic), and 75 deg E (Indian). The spare satellite will be parked at 72 deg E.

The satellites transmit 9.8 W of power into a 14 m dish. The service links are comprised of four 5 MHz-wide SA-WCDMA channels occupying the 20 MHz wide UHF uplink and downlink bands.