CMAB: Cross layer mobility-adaptive broadcasting in mobile ad hoc networks

Broadcasting is a fundamental operation underlying different routing, multicasting and address resolution protocols. Broadcasting in a network requires that all the nodes in the network receive the broadcast packet. Mobility in the network induces link failures which cause some nodes to lose the broadcast packets. Objective of all broadcasting protocols is to achieve high reachability while keeping the broadcast redundancy as low as possible. In this paper we propose a cross layer protocol, called cross layer mobility adaptive broadcasting (CMAB) to handle the mobility in mobile ad hoc networks (MANETs). CMAB uses two Disjoint Sets of Broadcast Relay Gateways (BRGsl and BRG2) to ensure high reliability in case of high mobility. Our approach minimizes broadcast redundancy by activating the second set of BRG2s only in highly mobile scenarios. A further reduction in broadcast redundancy is achieved by forcing the second Disjoint BRG2 to rebroadcast only if it is covering a maximum number of 2-hop neighbors of upstream sender or source to be covered by BRG1. The proposed protocol balances the retransmission redundancy avoiding the broadcast storm problem and increasing reachability in highly mobile and denser network scenarios. Simulation results show that CMAB provides high delivery ratio, low forwarding ratio and low end-to-end delay in highly mobile and denser network scenarios.