A Peer-Tree Based Location Lookup Service in Mobile Wireless Networks

We present a location look-up service for aiding location-based routing in wireless networks with mobile hosts. This location look up service is constructed based on a peer-tree indexing structure which represents the friendship relations among mobile hosts. The friendship is derived from the relations of sharing various-length common suffixes of host identifiers. A friendship relation determines the cooperation relation among mobile hosts. The Peer-Tree indexing structure provides a guideline for propagating location updates and queries in an organized manner. Each host periodically propagates its up-to-date location to a small number of its friends. Location queries are forwarded to and serviced at one of the hosts which hold a copy of the location under query. Paths for forwarding location updates or queries are jointly determined by the Peer-Tree indexing structure and the temporary connectivity in a network. The goals of this location look-up service include achieving a high success rate on location discovery, having low demands on network resources, and being robust to frequent changes of network topology.