Design and implementation of radio access link for group call service based on TD-SCDMA network

PoC (Push to Talk over Cellular) is a kind of new real-time voice services which can be realized in TD-SCDMA network. The point-to-point communication and the point-to-multipoint communication are provided in the same mobile communication system. The same information is shared by users in different locations. In view of the communication features of group call service, the limited radio channel resources and the utilization of existing network elements in TD-SCDMA network, TD-SCDMA network structure which supports the group call service is designed. At the same time, the functions of main network elements are described. Then it is a focused discussion that TD-SCDMA system adopts wireless channel allocation mechanism for group call service, especially in traffic channel allocation mechanism. The communication protocols of the group call are given in detail. Finally, the group call communication is simulated by using OPNET software. The performance of group call and the impact on TD-SCDMA network are analyzed. The result shows that the radio resources can be efficiently shared by group call members after adopting the rational network structure and wireless channel allocation mechanism. It provides technical support for the development of PoC service based on TD-SCDMA network.