casting assignments in The inter satellite service allocations are all above 20GHz and nearby foreign countries. There are, however, no frequency assign- most of them are in parts of the millimetre wave frequency range ment plans in Regions 2 and 3. In Region 2 the broadcasting service where absorption is high, due to molecular resonances in the atmos- is protected from interference from the fixed and mobile services pheric gases. All the bands are shared with other services but the mostly by the secondary allocation status which the latter services inverse distance squared attenuation on potential interference paths, have. In Region 3 all of these services have primary status and the augmented by atmospheric absorption where it arises, makes partition of the bands between these various services is largely at the troublesome interference to or from stations of other services im- discretion of each administration, in consultation where necessary probable. with neighbouring administrations. A frequency co-ordination process, based on the one referred to in Finally there are little used broadcasting allocations at 12, 42 and Section 26.4.2.6 above, is used to limit interference between inter 85GHz. These bands are mostly shared with the fixed, mobile and satellite links. broadcasting satellite services. It is likely that the availability of these bands for the telecommunication services will be determined 26.4.6 The broadcasting services mainly by broadcasting satellite developments. 26.4.6.1 Terrestrial broadcasting 26.4.6.2 Satellite broadcasting In Region 1 there is a broadcasting allocation around 200kHz. World wide there is another allocation within the approximate limits of 530kHz and 1700kHz. Several relatively narrow bands between World wide frequency assignment plans have been agreed for the 2MHz and 5MHz are allocated for broadcasting, mainly in tropical broadcasting satellite service (ITU, 1990, Appendices 30 and 30A) International spectrum management 26/13 17-20 GHz (RH SCALE) 12-13 GHz 8-12 GHz 3-8 GHz 