Date Added: Jan 2011
A Mobile Ad hoc NETwork (MANET) 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) routing protocol and other on demand 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.