Split-proxy concept for application layer handover in mobile communication systems

This paper presents an HTTP based approach for handover within and between heterogeneous communication systems. Therefore a split-proxy concept has been developed, consisting of client- and server side proxies. Communication between proxies takes place using TCP connections, thus benefiting from existing IP mobility approaches and virtual serial connections as provided by Bluetooth or circuit switched access. The latter allows one to forgo a full TCP/IP stack allowing very light-weight implementations on resource limited client devices such as smart phones. Furthermore, the protocol allows payload data caching and retransmission in case of gaps of network coverage. Throughput measurements indicate that the signaling overhead for the inter-proxy communication can be very well compensated by HTTP header and optional payload compression.