Demand assignment VSAT system compatible with the ISDN
Hajime Nakamura, Fumio Watanabe · 15th International Communicatons Satellite Systems Conference and Exhibit · 1994
In this paper we propose a new configuration of s a d lite communication systems using very small apcrturc terminals (VSATs) to provide a terminal-network interface compatible with ISDN. The proposed VSAT system supports thc I-interface (the basic interface) of the ISDN for uscr's terminal equipment, and the system can be interconnected with the ISDN at the I-interface as if it were a network termination. The system will be effective as an ISDN subscribcr transmission system or a private digital network compatiblc with thc ISDN interface. It embodies features of its intcrface techniquc to ISDN, protocol of demand assignment control on satellitc channels, and interworking mechanism betwccn an ISDNPBX and a computer. The ISDN-PBX at a hub station pcrforms all functions dealing with the layer-2 ant1 laycr-3 protocol. Each VSAT, on the other hand, handles only layer-l signals. Consequently the system can be implemented cconomically and simply. We have assembled an expcrimcntal system in order to confirm the feasibility of Lhc configuration. Thc paper describes some technical aspeccs of thc expcrimcntal system, specifically the interface bctwccn ISDN m i VSATs and the method of dcmand assignment control and signalling.