Preemptive Multipath-Adhoc On Demand Distance Vector Routing Protocol

A mobile ad hoc network (MANET) [1] consists of a set of mobile hosts capable of communicating with each other without the assistance of base stations. The topology of ad-hoc networks changes rapidly. The Ad hoc On Demand Distance Vector (AODV) [2] routing protocol and other ondemand routing protocols suffers with many problems like delay and packet loss caused due to link break, time required in route re-discovery, and high routing over heads. Existing on-demand ad-hoc routing protocols starts route re-discovery only after a link break occurs, which incurs a significant cost in finding the link break and in establishing a new route. Preemptive routing algorithm tried to solve this problem by initiating route re-discovery before the actual link break occurs. But time requires in finding new route increases delay in data transfer. In this paper, Preemptive Multipath-AODV (PM-AODV) routing protocol is proposed to enhance the performance of AODV routing protocol by overcoming the listed inherited problems. Our proposed scheme PM-AODV uses the concept of Ad hoc on demand multipath distance vector (AOMDV) [5] and Preemptive routing protocol. Similar to AOMDV routing protocol, PM-AODV stores multiple disjoint routes from source to destination during route discovery phase. Route maintenance phase of PMAODV is similar to preemptive routing protocol but instead of starting new route discovery source node switch to alternate already stored path for data transfer. This switching to previously stored alternate path reduces route re-discovery latency time. A comparison of the proposed scheme with AODV and preemptive routing protocol is also presented. The proposed scheme reduces global flooding and increases bandwidth utilization. It also reduces number of packet drops caused by link break in AODV.