Creating motives for cooperation to achieve high throughput in wireless ad hoc networks

In wireless ad hoc networks, nodes that are not within the same transmission range communicate using intermediate nodes as relays. Due to their limited battery life, wireless nodes can decide to deny incoming relay requests, in which case the network´s connectivity and aggregate throughput decreases. In this paper, we describe two algorithms that create motives for cooperation among node in an ad hoc network. The first algorithm, called neighbor GTFT (N-GTFT) is an extension of the GTFT (generous tit-for-tat) algorithm presented in V. Srinivasan et al. (2003), according to which a node relays packets for a particular neighbor based on the amount of given help it has received from that neighbor. The second algorithm maintains the difference between the amount of received and the amount of given help within bounds defined by a token bucket, and yields higher throughput in the case of bursty traffic. Both algorithms can be extended to a weighted version, which inappropriate when the destinations are not uniformly distributed, as in the case where most nodes send traffic to an access point.