Optimal Zone (OZON) Protocol for Broadcast Control in Ad-Hoc Networks

Mobile ad-hoc networks have been envisioned as the future of wireless networking technology. Continuous efforts are being put to improve the performance of ad-hoc networks in terms of path selection, quality of service (QoS), battery efficiency and security. Various routing protocols (proactive and reactive) have been proposed in this field for selecting the best path between the source and the destination. Self Learning Ad-Hoc Routing Protocol (SARP) is one such routing protocol which tries to reduce the control overhead during the path establishment process by piggybacking the information about the intermediate nodes in every path establishment message. Broadcasting of route discovery messages is an essential process in an ad-hoc network. However, in most cases, every node rebroadcasts these messages, resulting in broadcast storms which affect the ad-hoc network performance. In this research work, the authors propose a multicast based approach, i.e., Optimal Zone (OZON) with respect to SARP routing protocol, to control the number of rebroadcasts. OZON defines an optimal zone for every node where only the nodes at the boundary of the optimal zone are allowed to rebroadcast the messages. This reduces the number of broadcast messages in an ad-hoc network to a large extent and also helps in conserving the battery power. The authors evaluate the efficiency of the proposed OZON concept by comparing the performance of OZON enabled SARP (EE-SARP) with AODV, DSR and SARP. Simulation results indicate a significant reduction in the number of control packets and energy consumption.