Hierarchical Location-Based Services for Wireless Sensor Networks

Abstract

Nowadays Wireless Sensor Networks have attracted worldwide research and industrial interest, because they can be applied in various areas. Geographic routing protocols are very suitable to wireless sensor networks because they use location information when they need to route packets. Obviously, location information is maintained by Location-Based Services provided by network nodes in a distributed way. The location based services can be classified into two classes: Flooding-Based and Rendezvous-based location services.In this paper we choose to compare two hierarchical rendezvous location based-services, GLS (Grid Location Service) and HLS (Hierarchical Location Service) coupled to the GPSR routing protocol (Greedy Perimeter Stateless Routing).The simulations were performed using NS2 simulator for wireless sensor networks to evaluate the performance and power of the two services in term of location overhead, the request travel time (RTT) and the query Success ratio (QSR).This work presents also the scalability performance study of both GLS and HLS, specifically, what happens if the number of nodes N increases. The study will focus on three qualitative metrics: The location maintenance cost,the location query cost and the storage cost.