Recent progress in deployment and standardization of geostationary mobile satellite systems

We describe recent progress in the development and standardization of two geostationary mobile satellite systems (GMSS). These standards, denoted GMR-1 and GMR-2, for GEO mobile radio 1 and 2, were developed jointly in both US (TIA) and European (ETSI) standards bodies, and the complete set of standards have recently been published. In parallel, two regional geostationary mobile satellite systems using these standards have been launched and have commenced service. The Thuraya system, using GMR-1, serves a region centered in the Middle East, and the Asia Cellular System (ACeS), using GMR-2, serves a region in southeast Asia. This paper describes the key features of both systems, and the status of current and future GMSS standards.