Reducing group management overhead in group-based location management

Location management is fundamental in supporting location-dependent applications in a mobile environment. It is crucial to reduce the high uplink communication cost in reporting the location of mobile hosts. Group-based location updating scheme is able to exploit the spatial locality of mobile hosts to generate an aggregated location update from a group leader, thereby reducing the number of high cost individual location updates to the server. Under such a scheme, group management becomes an integral component for maintaining hosts' membership. A mechanism is needed for a mobile host to find a suitable group for joining. Those tasks induce more local messages. Based on our preliminary work, host interaction in the group finding process becomes a dominant factor in generating a high local communication overhead. Two improved variants of the group joining procedure are proposed for reducing the overhead. Performance study indicates that both variants do lead to a drastic reduction in local message count and hence the aggregated communication cost.