Using “refuge proxy” to prevent packet loss/out-of-sequence and path loop in micro-cell wireless networks

In a micro-cell packet switching mobile network, handover may cause packet loss, packet out-of-sequence and even path loop. These mishaps can be prevented by the transport layer protocol employing end-to-end packet re-transmission and path re-calculation, which however are prohibitively expensive and inefficient under the trend of decreasing micro-cells size and increasing mobility. We present a novel architecture and handover protocols based on the concept of refuge proxy. A refuge proxy, as a shared, stand-by agent, allows handover avoiding packet loss/out-of-sequence and path loop on the network layer. Unlike a plain forwarding scheme, this architecture minimizes the overhead of signaling and synchronization at base stations. When packets are stranded at a base station, they are simply sent to a close-by refuge proxy and subsequently forwarded to the new base station. The signaling and synchronization is handled largely by refuge proxies; when consecutive handovers during a conversation lead to a network path loop (e.g., a mobile station moves out a micro-cell and later comes back), the refuge proxies help remove the path loop. The idea of using refuge proxy for efficient handover may also be suitable for other types of PCS networks