Energy-efficient location services for mobile ad hoc networks

Location-based routing protocols are stateless since they rely on position information in forwarding decisions. However, their efficiency depends on performance of location services which provide the position information of the desired destination node. Several location service schemes have been proposed, but the most promising among them, hierarchical hashing-based protocols, rely on intuitive design in the published solutions. In this paper, we provide full analysis of the efficiency of routing in hierarchical hashing-based protocols as a function of the placement of the routers. Based on the theoretical analysis of the gain and costs of the query and reply routing, we propose a novel location service protocol that optimizes the distance traveled by the location update and query packets and, thus, reduces the overall energy cost. These gains are further increased in the second presented protocol by the optimal location of servers that we established through analysis of geometrical relationships between nodes and location servers. Simulation results demonstrate that the proposed protocols achieve around 30-35% energy efficiency while improving or maintaining the query success rate in comparison to the previously proposed algorithms. (C) 2012 Elsevier B.V. All rights reserved.