some particular scenarios, locations of mobile hosts become
as important as their identifiers in ad hoc routing in mobile
wireless networks. Location lookup services are henceforth
needed to aid location-based routing.
In this paper, we present a source routing based location
lookup service that can be used as the location discovery
component in a location-based routing protocol. The design
goal of this service lies in two folds: having high success
rates on location discovery while keeping low demands on
network resources. The goal of having high success rates is
achieved through encouraging mobile hosts to cooperate in
serving location queries. The goal of keeping overhead low
is achieved through making each location query be served
by a small number of hosts.
Each mobile host is associated with a number of friend
hosts and distributes replicas of its up-to-date location to
them in order to enhance chances of answering queries
about its location. Discovering or updating the location of
a target host is served through the cooperation among a set
of friends of the target host. The friendship among mobile
hosts forms into an index structure used in our location
lookup service. In order to ensure a small number of
hosts participating in serving a location query, we construct
the index structure into a complete binary search tree and
distribute it across mobile hosts. DSR routing protocol has
been modified and used in forwarding location lookup service
related packets. The path of forwarding packets reflects
underlying temporary connectivities among mobile hosts.
Evaluated by simulating mobile wireless networks, the
performance of our location lookup service exhibits high
success rates and low demands on network resources.
Keywords— Location Lookup Service, Dynamic Source
Routing,Wireless Ad Hoc Networks