Simultaneous Handover Support for Mobile Networks on Vehicles

With high mobility rates of vehicles, there may be frequent occurrences of simultaneous handover. Our work focuses on and straightens out the problems resulting from simultaneous handover in SIP-NEMO. This article proposes a proxy-aided simultaneous handover (PASH) mechanism for the architecture of mobile networks operating on vehicles. The system architecture is modified from SIP-NEMO. We design a Fast Route/local routE re-Establishment (FREE) algorithm capable of re-establishing the optimized routing path fast and ensuring signaling messages buffered in local proxy could be sent to the correct destination without loss. Moreover, the Master- Slave Determination procedures derived from H.245 are introduced to handle the racing conditions fairly when two local proxies involved in a simultaneous handover issue re-INVITE requests at about the same time. Analytical results show that the handover delay can be improved significantly using the PASH, compared with the home-aided simultaneous handover.