Fatemeh Tavakoli - Department of Computer Engineering, Aligudarz Branch, Islamic Azad University, Aligudarz, Iran
Meisam Kamarei - University of Applied Science& Technology (UAST), Tehran ,Iran
Gholam Reza Asgari - Department of Computer Engineering, Aligudarz Branch, Islamic Azad University, Aligudarz, Iran

In this paper, an efficient fault-tolerant routing algorithm for Mobile Ad-hocNetworks (MANETs) is presented. The proposed algorithm increases the networkfault-tolerance using natural redundancy of Ad-hoc networks. This algorithm iscarried out in two stages; 1)the selection of backup nodes 2) the selection of backuproute(s). In the first stage, the proposed algorithm chooses nodes with the same pathas backup nodes. Prediction and diagnosis of nodes` paths is performed throughbackup tables. Since the selection of backup nodes is fulfilled, the proposedalgorithm begins fault-tolerance routing. For this purpose, initially the proposedalgorithm provides the main route between each pair of source & destination nodesbased on DSR routing algorithm. Then, from a destination node towards a sourcenode, the backup route(s) is established between the chosen backup nodes in the firststage. Experimental results taken from NS-2 simulator demonstrate that incomparison with previous methods the proposed increases; 1) 10% the pachagedelivery ratio against the percentages of faulty nodes, 2) 22% package deliveryratio against the pause time of various mobile nodes.

Backup Nodes, Mobile Ad- hoc Networks, Fault-tolerance, Redundancy Routing