Packet forwarding strategies for cooperation enforcement in mobile wireless ad hoc networks

Abstract

In self-organized ad hoc networks, all networking functions rely on the contri- bution of the relay nodes. Nodes have to forward packets for each other in order to enable multi-hop communication. In recent years, researchers have identi ed the problem of stimulating cooperation in ad hoc networks and proposed several solutions to give nodes incentive to contribute to common network services. These solutions are based on incentive mechanisms like reputation based system or virtual currency based system. This paper aims at determining conditions under which, such cooperation without incentives can exist, while taking the network topology into account. We have focused on the most basic networking mechanism, namely, packet forwarding and proposed a game theoretic approach for achieving cooperation. We have de ned a game model where nodes act as players, their actions (forward or drop a packet) de ne strategies and they are given payo s based on the payo functions designed in terms of network parameters. We have considered di erent parameters for simulation like tramsmission range, di erent strategies, initial condition of nodes, energy cost for sending or forwarding packets, tra c rate, noise e ect, mobility, etc. Our simu- lation result shows how cooperation is achieved in network with nodes getting better payo s. Later we have extended our work to cover network with mobile nodes.