ENERGY EFFICIENT CLUSTERING AND FAULT TOLERANCE IN MOBILE ADHOC NETWORKS

Abstract

Mobile ad hoc networks (MANET) technology is used for communications during emergency newlinesituations like disaster management and military deployment, which don t have any fixed newlineinfrastructure.This has drawn much attention for research, due to its adhoc nature. The newlineinfrastructure based cellular architecture sets up base stations to support the node mobility. Thus, newlinemapping the concepts of base stations into MANET could meet its challenges like limited battery newlinepower, scalability, available band width etc. This leads to the design of logical clusters, where newlinethe cluster heads in every cluster play the role of base station. The cluster heads also form the newlinevirtual back bone for routing the packets in the network. As MANET is very much used for newlineemergency communication, this network should meet with this challenges and it must tolerate newlinethe faults occurred due to node death and link failure. In this thesis, simulation based survey has newlinebeen made to study the strengths and weaknesses of existing algorithms that motivated for the newlinedesign of energy efficient clustering in MANET. newlineNeighbour Detection Protocol (NDP) has been designed to help the nodes to probe their newlineimmediate neighbours. In this protocol, every node broadcasts its own information to the newlinenetwork, so that it is received by a node that lies within its transmission range. The receiver newlinesenses its neighbours and updates its neighbour table (NTAB) from time to time. newlineEnergy Efficient Clustering for Fault Tolerance (EECFT) algorithm has been proposed in newlinethis work , that uses the node mobility and its available battery power for calculating the node newlineweights. A node having the highest weight among its immediate neighbours declares itself as the newlineprimary cluster head. As the current head consumes its battery power beyond a threshold, newlinesecondary cluster heads are selected locally. The algorithm aims to utilize the battery power in a newlinefairly distributed manner so that the total network life time is enhanced with reduced cluster newlinemaintenance overhead. newlineDuring the process of clustering, some isolated heads without having any members are newlineformed. This increases the delay in communication as the number of hops in the routing back newlinebone is increased. In this work Modification of Transmission Range in Isolated nodes (MTRI) has newlinebeen proposed, that allows the isolated nodes to adjust their ranges to maintain connectivity with newlineexisting cluster heads. The results show that, MTRI reduces the delay in communication by newlinereducing the number of cluster heads in the network. newlineA local repair algorithm is proposed with the aim of providing fault-tolerance a critical newlinefeature in providing QoS in the link failure prone environment of mobile networks. Performance newlineof this new fault-tolerant cluster based QoS wireless algorithm is evaluated according to failure newlinerecovery time, dropped packets, throughput via simulations involving various node failure newlinescenarios along QoS paths. newlineEach of the proposed work is evaluated separately to analyze their performances and newlinecompared with the competent results. newline