A USER DEVICE, A CALL CONTINUITY APPLICATION SERVER AND A NETWORK SWITCH METHOD

摘要

A network switch method is provided. The method is applied to network switch during the process of ringing/ring back tone or the process of call holding, in which the implementation process is that a party performs call negotiation with another party on the opposite side through the call continuity application server during the process of ringing/ring back tone, after negotiation succeed, the party transmits a off-hook signal to the opposite side through the call continuity application server. Furthermore, a call continuity application server and a user device are provided. In the present invention, during the process of ringing/ring back tone or the process of call holding, the user device also can switch to another network through the call continuity though the network coverage is not good, so that it can effectively avoid the user device call-off during the process of ringing/ring back tone or the process of call holding, and improve the call quality of the user.