Patent attributes
A handoff method in a communication system where BSs providing different radio access interfaces to an MS are connected to an IP-based network through routers. A handoff from a first BS to a second BS is decided for an MS that receives IP service data from the first BS and an L2 connection is established between the MS and the second BS. During the L2 connection establishment, movement of the MS in the IP network is detected. Handoff negotiations are conducted between the first and second BSs by IP signaling. If the handoff is available according to the negotiations, mobility management control is performed considering movement of the MS. The IP service data is transmitted to the MS in a network path reset to the second BS by the mobility management control and an L2 connection is released between the MS and the first BS.