AHYBRID PROTOCOL FOR WIRELESS AD HOC NETWORKS OVER THE VHF LINK

Abstract

Rapid advancements in wireless technologies have fuelled parallel research in two areas, one in which wireless devices use a central authority to establish and maintain the network and one in which no such central authority is used. Mobile Ad-Hoc networks (MANETs) are part of the latter research. Most researchers define a mobile Ad Hoc network as "a self-organizing network formed on the fly without the aid of any established infrastructure or central authority". Many routing protocols have been developed to establish and maintain routes in MANETs. They try to address the unique challenges that MANETs present over traditional wired networks. Some of these challenges are use of unreliable wireless medium for communication and lack of a central authority to facilitate any communication in the network. These protocols find a route to a destination if such a route exists. However, in the wireless medium, there are quite a few options that have not been explored. For example, no implementation has been focused to address the possibility of using VHF for Ad Hoc networks. In general, all the routing protocols can be used for communication over every kind of wireless link. However, in this project we have presented an approach to implement a new routing protocol for application specific to a VHF device and a MAC protocol to match the requirements of the routing protocol in the given scenario. Our protocol uses the concept of MPR nodes as taken from OLSR to act as the local routing heads to reduce congestion of network due to control messages and for better utilization of bandwidth and other network resources. This report describes the protocol in detail and provides a simulation-based evaluation of its performance compared to other possible schemes and the optimal scheme.