A GEO satellite mobile telecommunications system architecture design based on UMTS/S-UMTS

China has begun to consider the plan of establishing its public satellite mobile network (PSMN) due to the national demands. As the result of one earlier research sponsored by the Ministry of Science and Technology of China, a network architecture of the satellite mobile service system, which is compatible to 3GPP/UMTS R4 and bases on appropriate GEO satellite on-board processor modeling, is proposed in this paper, with several new defined functional entities, interfaces, and protocols. The proposed network architecture could act as a basis of further design of the China's PSMN system.