METHOD, DEVICE AND SYSTEM FOR MAINTAINING CONTINUITY OF GROUP COMMUNICATION SERVICE

摘要

Disclosed are a method, device and system for maintaining the continuity of a group communication service, for solving the problem in the prior art that the service continuity requirement of group communication may not be satisfied due to the switching of network service from multicast transmission to unicast transmission in an MBSFN domain. The method comprises: when determining that group communication service needs to be switched from multicast transmission to unicast transmission, a GCSE-AS notifies a terminal served by the GCSE-AS that the GCSE-AS is going to switch the group communication service from multicast transmission to unicast transmission; and after receiving a first notification message transmitted by the terminal, the GCSE-AS transmits the group communication service over a unicast carrier established by the terminal for unicast transmission, and stops transmitting the communication service in multicast mode. The terminal has already established a unicast carrier for unicast transmission before the GCSE-AS switches the group communication service from multicast transmission to unicast transmission, thus ensuring the continuity of the group communication service.