An Empirical Study on Mobile Explicit Multicast for Small Group Communications

We perform an empirical study on mobile explicit multicast, named XMIP, by enhancing explicit multicast for a great number of small group multicast communications. XMIP is a straightforward multicast mechanism without maintaining multicast states due to the inheritance from the explicit multicast based on a unicast routing. This research modifies and extends the functionality of each mobility agent of IETF mobile IP. XMIP packets captured by an extended home agent are forwarded to each extended foreign agent through X-in-X tunnels made by the binding table of the extended home agent. X-in-X tunneling mechanism can effectively solve the serious traffic concentration problems of mobile IP multicast specifications. Finally WLAN-based testbed including 3G CDMA is built and a multi-user instant messenger system for small group communication is developed for verifying the feasibility of the implemented XMIP protocols