PROTOTYPE OF A DIGITAL ON-BOARD PROCESSOR FOR SATELLITE COMMUNICATION OF MOBILE TERMINALS

In recent years the growing demand for satellite communication changed the old idea of "repeaters in the sky" into the new one of "switchboards in the sky". In particular, new requirements emerged in terms of: connections to fixed earth stations, mobile terminals and other satellites; new services; access schemes to cope with different RX/TX equipment of the various terminals in connection with the satellite. Following this trend a prototype of a digital on-board processor for mobile communications is now under development at Laben; it provides on demand circuit-switched services (i.e. voice and bidirectional low data rate channels) and packet-switched services (i.e. direct forwarding of short mesages). A variety of satellite access schemes has been analyzed and implemented. This paper describes the prototype architecture and its main features.