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United States Patent | 3,564,147 |
Puente , et al. | February 16, 1971 |
A demand assigned multiple access system provides for the sharing of satellite circuits by a large number of terrestrial users. Demand assignment of satellite circuits is especially useful and efficient to the developing nations as compared to preassignment of satellite circuits, since they have a low number of call minutes per day. Terrestrial transmissions are FDM multiplexed through the satellite on a single channel or carrier, and since no carriers are preassigned between specific terrestrial locations, any ground station may select any one of the carriers available in the entire system, provided that carrier is not presently in use. A common TDM channel is used at all terrestrial locations for maintaining a record of the carriers used and requested by all locations.
Current U.S. Class: | 370/321 ; 370/324; 370/330; 455/13.2 |
Current International Class: | H04B 7/204 (20060101); H04B 7/185 (20060101); H04J 4/00 (20060101); H04j 001/14 () |
Field of Search: | 325/4,39,40,54,57,58,15 (SAT)/ 325/3 343/176,200 179/15,15 (SIG)/ 179/15 (ATI)/ 179/15 (AS)/ 179/15 (Async)/ 179/15 (APR)/ 179/15 (MM)/ |
3261922 | July 1966 | Edson |
3363180 | January 1968 | Geissler |