Fault tolerant polynomial time for minimum cost path routing in MANET

Link failure is common in dynamic topology network. Link failure occurs due to mobility of nodes, power limitation and resource failure in the network. The links in MANET are of dynamic topology having high rate of interruption causing link breakage. Therefore the link recovery mechanism has to be employed in MANET to recover from resource failures. This paper presents a method to find an alternative path from source to destination after the link failure occurs in network, before the IGP (Interior Gateway protocol) has had a chance to reconverge in response to the failure. Since IGP takes hundreds of milliseconds to re-converge, therefore there is a need to find a method which will find a alternative path in less time than IGP. The target application is limited to small number of nodes in network. This paper develops a solution to convergence problem by using two approaches namely: 1) Detect link failure before IGP convergence; 2) Developing a polynomial time modified Dijkstra based minimum cost path routing.