[attachment=232]
Abstract
A mobile ad hoc network is a mobile, multihop wireless network that does not rely on any preexisting infrastructure. Mobile ad hoc networks are characterized by dynamic topologies due to uncontrolled node mobility, limited and variable shared wireless channel bandwidth, and wireless devices constrained by battery power. One of the key challenges in such networks is to design dynamic routing protocols that are efficient, i.e., consume less overhead. The key characteristic of an on-demand protocol is the source-initiated route discovery procedure. Whenever a traffic source needs a route, it initiates a route discovery process by sending a route request for the destination (typically via a network-wide flood) and waits for a route reply. Each route discovery flood is associated with significant latency and overhead. This is particularly true for large networks. Therefore, for on-demand routing to be effective, it is desirable to keep the route discovery frequency low. Among the on-demand protocols, multipath protocols have a relatively greater ability to reduce the route discovery frequency than single path protocols. On-demand multipath protocols discover multiple paths between the source and the destination in a single route discovery. So, a new route discovery is needed only when all these paths fail. In contrast, a single path protocol has to invoke a new route discovery whenever the only path from the source to the destination fails. Thus, on-demand multipath protocols cause fewer interruptions to the application data traffic when routes fail. They also have the potential to lower the routing overhead because of fewer route discovery operations.