MSAT interactive mobile data services

The interactive mobile data services implemented in the multi-beam MSAT ground segment are presented. The mobile data system (MDS) provides two-way packet switched data communications between mobile terminals and fixed terrestrial users. It also supports mobile-to-mobile communications through the data hub. The MDS supports two types of services: the basic services: X.25 and asynchronous interactive terminal interface, and the specialized services which have been tailored to fit the multiple access schemes. The specialized services which consist of the reliable transaction service and the unacknowledged data service are described in detail. Performance analysis of the network is discussed. Results from simulating the satellite protocols are introduced reflecting channel throughput and loading as well as network response time for different traffic models. Finally, various mobile applications are introduced and analyzed