Low-cost TDMA for the INTELSAT system

The employment of Time Division Multiple Access (TDMA) techniques in communications satellite systems makes it possible that all earth stations operating via the same satellite may communicate directly with one another via the same earth station equipment. Because of this benefit and some other advantages of TDMA, it appears that TDMA provides a preferred modulation and multiple access technique for the INTELSAT systems. However, in the earlier years of communications satellite systems, the implementation costs of TDMA were higher than those required in the case of other techniques. Since 1978, a significant development effort has been exerted toward reducing the cost of TDMA. The various developments leading to a low-cost TDMA for the INTELSAT system are discussed, taking into account large scale integrated circuits advances, the INTELSAT TDMA system with Digital Speech Interpolation (DSI) equipment, integral TDMA/DSI design, and the TDMA control processing architecture.