Global mobile N-ISDN satellite communication system

Current and planned global mobile satellite systems (MSSs) are aimed mainly at serving voice, facsimile and low-bit-rate data services with rates of up to about 4.8 kbit/s. In the multimedia communication era, however, this channel rate, regardless of the use of GEO or LEO satellites, is too low to realize comfortable mobile computing for operations such as Internet access, e-mail, remote LAN access, image transmission, and videophone. This paper proposes a global mobile N-ISDN satellite communication (GMISC) system: a GEO satellite communication system offering the ISDN basic rate up to 144 kbit/s (2B+D) with notebook size user terminals and vehicular terminals to provide a comfortable nomadic communication environment. It also discusses satellite channel control techniques for the proposed GMISC system. It is clear that a layered satellite channel control scheme consisting of a master satellite channel controller and plural local satellite channel controllers that assign shared satellite channels within a country, is suitable for the proposed system