The European Communications Satellite multi-service transponder

The various ways in which the transponder can be used are described. It is noted that the multiservice transponder must provide data channels for the following rates: 64, 128, 256, and 1920 kbit/s in point-to-point and point-to-multipoint mode. Attention is called to the need for simple earth stations which will minimize the earth segment cost. It is shown that a single-channel-per-carrier FDMA system is a suitable solution since it provides reasonably high capacity through the use of forward error correction (approximately 550 64-kbt/s channels) while allowing freedom to modify the channel performance by increasing the carrier power level. Another advantage of the FDMA approach is that different modulation/access techniques can be used on individual frequencies, and the operation of 2 Mbit/s TDMA systems on one or more of the allocated frequencies can be foreseen.