GrLS: Group-Based Location Service in Mobile Ad Hoc Networks

In this paper, we propose a group-based location service protocol named GrLS for mobile ad hoc networks (MANETs). The novelty of GrLS is in its exploitation of group mobility to improve the efficiency of the location service. GrLS uses different location management strategies for single nodes and for groups of nodes. A single node is responsible for recruiting its own location servers and performing location update. On the other hand, in a group of nodes, only the group leader recruits the location servers and updates its location to a specific home region called group home region. Since the location update cost normally dominates the location service cost for all practical purposes, the overhead of the location service protocol is significantly reduced. Furthermore, when the nodes join or leave groups, GrLS can provide seamless location service handoff. To the best of our knowledge, GrLS is the first location service protocol in MANETs that has explored group mobility and developed group location management for mobile nodes. Both theoretical analysis and simulation results show that GrLS can achieve a higher success ratio of location query and better load balance with much lower overhead than the existing protocols without considering group mobility.