Energy efficient broadcasting in wireless Ad hoc networks

Abstract

Energy efficiency is a key issue in research area of wirc1ess,ad hoc and sensor network. Many wireless applications are inherently broadcasting based and here the energy consumption issue becomes even 'more pronounced. To address the problem numerous approaches are proposed throughout the last decade. Among these proposed schemes, construction of Connected Dominating Set (CDS) is well established. Research in this area has been fostered by incorporation of selectable directional antennas for the last few years. Reducing number of open antennas significantly conserves energy of wireless node as unnecessary transmissions or receptions may be avoided. In this thesis, we have devised a localized deterministic distributed heuristic to incorporate directional antennas to a CDS which ensures connectivity of wireless nodes and minimizes energy consumption for broadcasting. Considering the best case scenario, we calculated the gain of using our antenna with mathematical analysis. Here we found expected number of open antennas after applying our proposed approach decreases significantly. This decrease in number is inversely proportional to density of the network. This is supported by the simulation analysis. We simulated our proposed algorithm using Network Simulator-2 (NS-2) and found that it increases energy efficiency to a considerable extent. The performance is tested for several topologies with random number of nodes in terms of over all energy consumption of the network and also for the individual nodes which die first. We found in the simulation result that in both these criterion our proposed scheme perfon11S better. However, perfomlance improvement decreases with the increase in node density. Still for all the topologies consisting of different number of nodes (i.e. 25, 50, 100) that we used in our simulation, our approach performs considerably better compared to traditional approaches. We have also analyzed the , possible case of local minima in case of routing over this backbone for specific types of network topologies.