Hierarchical Geographic Multicast Routing for Wireless Sensor Networks

Multicast is a fundamental routing service for efficient data dissemination required for activities such as code updates, task assignment and targeted queries in large-scale wireless sensor networks. Recently, two protocols were proposed to optimize two orthogonal aspects of location-based multicast protocols: GMR [1] improves the forwarding efficiency by exploiting the wireless multicast advantage but it suffers from scalability issues when dealing with large sensor networks; HRPM [2] reduces the encoding overhead by constructing a hierarchy at virtually no maintenance cost via the use of geographic hashing but it is energy-inefficient due to inefficacies in forwarding data packets. In this paper, we present HGMR (Hierarchical Geographic Multicast Routing), a new location-based multicast protocol that seamlessly incorporates the key design concepts of GMR and HRPM and optimizes them for wireless sensor networks by providing both forwarding efficiency (energy efficiency) as well as scalability to large networks. Our simulation studies in an ideal environment and in a realistic environment confirm that HGMR exhibits the strength of both GMR and HRPM.