The operation mode selection in FMIPv6

The Fast Handover for Mobile IPv6 (FMIPv6) [2] aims at reducing the long handover latency in Mobile IPv6 [1] by fast movement detection and fast binding update. Furthermore, it also reduces packet loss by buffering before the real link layer handover takes place. Due to uncertain link layer trigger time, however, the buffering mechanism sometimes introduces unacceptable handover latency for realtime traffics such as voice over IP (VoIP). In addition, if it's the mobile node that makes the handover decision, FMIPv6 also suffers from uncertainty of handover target, which is unfavorable to TCP traffics such as FTP. In order to eliminate these negative effects, we propose that FMIPv6 should operate in predictive mode under the control of network if possible for TCP traffics. As to the VoIP traffic, in terms of the handover latency and packet loss requirements, a proposed hybrid mode is chosen adaptively. Numerical simulation results for the VoIP traffic demonstrate obvious performance improvement in terms of call drop rate and a new performance metric called packet cost.