9.3 International Telecommunication Union (ITU): Radio Regulations
The International Telecommunication Union (ITU), originally the International Telegraph Union, was formed in 1865. It became a specialized agency of the United Nations (UN) in 1947; it is responsible for issues that concern information and communication technologies.
The ITU-R was established in 1927 (as the International Radio Consultative Committee or CCIR) to manage the international radio-frequency spectrum and satellite orbit resources. In 1992, the CCIR became the ITU-R. The ITU-R regulations define the limitations and requirements for radio transmissions, and the restrictions on interference with allocated radio frequency bands.
Specifically, the ITU-R regulations include the allocation of the frequency bands:
· 406.0 to 406.1 MHz[1]: for transmissions from distress beacons to satellites in orbit. (This band is used by the Cospas-Sarsat distress beacons to send their distress messages.)
· 1544.0 to 1544.1 MHz[2]: for Cospas-Sarsat satellite emergency downlink transmissions. (This band is used by the Cospas-Sarsat spacecraft to relay the beacon signals back to the Local User Terminal ground stations.)
In support of these allocations, the ITU also assists with the monitoring and management of these frequency bands.
Participants in the Cospas-Sarsat Programme, and especially the Ground Segment Providers and Organizations, monitor the frequency bands that are allocated for the use of the Cospas-Sarsat System, and report any interference[3] that they detect to the ITU. The ITU then works with the national authority responsible for the location where the interference has been reported to eliminate the offending transmissions.
In 2015, the ITU amended the Radio Regulations to explicitly identify the danger of interference to the Cospas-Sarsat uplink band from transmissions in adjacent frequency bands. States (and especially Cospas-Sarsat Participants) are invited to monitor these frequency bands and to report any transmissions that may affect the reliable operation of the Cospas-Sarsat System.
[1] Regulation ITU-R M.1478-3
[2] Regulation ITU-R M.1731-2
[3] Interference in a radio signal is any signal that is not within the authorized use of the frequency band. Such interfering signals may degrade the performance, increase the error rate, or completely stop the reception of authorized signals in the band. Interference may come from natural sources or from man-made signals.