g satellite service and the associated feeder links around stations and those providing links to, and between, mobile stations. 14.6GHz and 17.7GHz (see Section 26.4.6). These two categories, including the satellite systems for each, comprise the fixed services and the mobile services. Extensive frequency bands have been allocated for them, and many are shared 26.4.2.2 Links via satellites between them. However, there are major differences in the regula- tory methods used in the international management of frequency Wide microwave and millimetre wave frequency bands are allo- assignments to fixed and mobile stations and spectrum management cated for the fixed satellite service. These allocations are used for for the two groups is considered separately in Sections 26.4.2 and links between fixed earth stations via satellites. 26.4.3. The amateur services follow in Section 26.4.4. The inter Feeder links may also be assigned frequencies in these bands. A satellite service, providing spectrum for inter satellite links for feeder link connects an earth station at a given location with a systems of any radio service, is reviewed in Section 26.4.5. satellite which is not of the fixed satellite service. The term covers, However, there are other kinds of radio system. About one half of for example, links between coast earth stations and satellites serving the spectrum below 1GHz is allocated for broadcasting. About one ships, links feeding programme material to broadcasting satellites third of the spectrum between 1GHz and 20GHz is allocated for and links used for down loading data from a data collection satellite. radars and similar position determination systems. There are lesser Some fixed satellite bands are allocated for transmission in the allocations for other specialised applications for radio. Some of this Earth to space direction (up links). The others are for the space to spectrum is shared with radio systems used for telecommunications Earth direction (down links). The important up link allocations are and the 