The EUTELSAT system - A multipurposed satellite system tailored to the needs of the European region

Design and performance features of the communications segment of the first European Communications Satellite (ECS) are described. The ECS was constrained by economic factors to augment, rather than replace, the existing terrestrial network and provide various services accessible by small earth-based dish antennas. An 11/14 GHz frequency mode was selected, along with a 120 Mbit/sec TDMA system, 80 MHz repeaters, and on-board switching. Nine active transponders are used with three spares ready in case of failures. The transmission capacity of the ECS is 44 telephony channels per MHz due to the implementation of TDMA, PCM, digital speech interpolation, and QPSK modulation. The bit error rate is expected to average one/million for 99 percent of the year. Ground antennas will have diameters that vary from 3.3-8 m, depending on the location relative to the coverage zone of the GEO-stationed satellite.