Patent ID: 8599821

Claim:
A method for changing the status of a packet switched domain, comprising: receiving, by a second terminal that has not activated the packet switched domain, an instruction for activating the packet switched domain, wherein the instruction is one of the following: a dual tone multi-frequency message that is generated by a first terminal and transmitted by a first switching center when the first and second terminals belong to the first switching center, wherein the dual tone multi-frequency message is transmitted by the first switching center and a second switching center when the first terminal belongs to the first switching center and the second terminal belongs to the second switching center, and a signaling message generated based on the dual tone multi-frequency message that is generated and sent by the first terminal, wherein the second terminal and the first terminal are in an ongoing circuit switched session in which the dual tone multi-frequency message is transmitted; and activating, by the second terminal, the packet switched domain according to the instruction.