taken of it in the design of satellites. vehicles. Thus, the ASTRA satellites of SES and the EUTELSAT II series, Various other satellite systems are also being set up to provide both transmitting in the 10.7GHz to 11.7GHz band, have relatively communication services to mobile stations and in particular to road large beam footprints for international coverage and are used, for vehicles. Some of these will operate in the same frequency bands as example, to distribute programmes to designated fixed earth station- INMARSAT. Others, and particularly some that are emerging in S for onward distribution to the public. However, the transponders North America, will use the frequency allocations at 800MHz to 960 of these satellites, being equipped with 50 watt transmitters, provide a signal strength on the ground which is not so very much less than the objective set for high power satellites in the planned 12GHz bands; in consequence these satellites tend to be seen by the public 51.6.4 Satellite broadcasting as broadcasting satellites and large numbers of homes treat them as such. Subject to various constraints to protect terrestrial radio services, and in particular terrestrial television broadcasting, which make extensive use of the same band and has superior allocation status, Future developments paragraph 693 of the ITU Radio Regulations permits satellite broad- casting to be done in the band 620GHz to 790GHz. The USSR has For communication by satellite between fixed earth stations the been using EKRAN satellites to broadcast FM TV in this band for distant future lies in a struggle, technical and economic, with terre- a number of years, providing signals that can be received over a strial systems, cabled or by radio relay system. How fast will the wide area. However, there seems to be little prospect that satellite public telecommunications network become converted to a univer- broadcasting will expand in this band. sally available, omni-purpose, global, integrated, synchronised, The main frequency bands foreseen for s