Multiservice on-board switching for mobile satellite communications

Future satellites for mobile communications will be required to interface ground ISDN (integrated services digital network) and to provide services and performances comparable with those offered by cellular radio networks. Onboard processing is a key technique to satisfy these requirements and can provide efficient integration with fixed satellite services. The European Space Agency (ESA) has started the development of a laboratory prototype of the baseband elements of a mobile satellite system, including the onboard processor and the mobile terminals. The prototype will handle several services (voice, circuit, and packet data) and will be compatible not only with laboratory testing, but also with in-field experiments through double-hops via existing transparent satellite. The network requirements and system architecture aspects are reviewed, the relevant access and synchronization techniques are outlined, and the processor structure and operation are described