Patent ID: 8644258

Claim:
A method for reducing break duration in a handover of a VoIP conversation, when a control device in a circuit switch domain receives a request of handover from a control device in a packet switch domain indicating a handover of a current conversation from the packet switch domain to the circuit switch domain, comprising: calculating a first time duration which is a time from transmission of a message from the control device in the circuit switch domain to a time the message arrives at a remote end communication terminal; generating a comparison result by comparing the calculated first time duration with a predetermined second time duration, the second time duration being a time from transmission of a message from the control device in the circuit switch domain to a time the message arrives at a local communication terminal; and determining, by the control device in the circuit switch domain, an order and time for transmitting a request of session handover to a device anchoring VoIP conversation and transmitting a request of cell handover to the control device in the packet switch domain based on the comparison result of the first time duration and the second time duration, and transmitting the two requests according to the order and time, to ensure that the request of session handover arrives at the remote end communication terminal at substantially the same time as the request of cell handover arrives at the local communication terminal.