Cooperation in wireless ad hoc networks

Abstract

Abstract-In wireless ad hoc networks, nodes communicate with far off destinations using intermediate nodes as relays. Since wireless nodes are energy constrained, it may not be in the best interest of a node to always accept relay requests. On the other hand, if all nodes decide not to expend energy in relaying, then network throughput will drop dramatically. Both these extreme scenarios (complete cooperation and complete noncooperation) are inimical to the interests of a user. In this paper we address the issue of user cooperation in ad hoc networks. We assume that nodes are rational, i.e., their actions are strictly determined by self interest, and that each node is associated with a minimum lifetime constraint. Given these lifetime constraints and the assumption of rational behavior, we are able to determine the optimal throughput that each node should receive. We define this to be the rational Pareto optimal operating point. We then propose a distributed and scalable acceptance algorithm called Generous TIT-FOR-TAT (GTFT). The acceptance algorithm is used by the nodes to decide whether to accept or reject a relay request. We show that GTFT results in a Nash equilibrium and prove that the system converges to the rational and optimal operating point.

The design of a reliable reputation system

“…Significant work in mobile ad hoc networks has gone towards stimulating cooperation and maximizing the throughput of the network [8,48]. In ad hoc networks, nodes communicate with far off destinations using intermediate nodes as relays.…”

Analysis of coalition formation and cooperation strategies in mobile ad hoc networks

“…In an interesting approach presented in [2] the authors propose a game theoretical model in which energetic information is taken into account to describe the conflicting interaction between heterogeneous nodes involved in a forwarding game, i.e. a game in which nodes that belong to a path from a source to a destination have to collaboratively relay data packets.…”

“…The authors study the properties of a well known strategy (generous-tit-for-tat, G-TFT) and demonstrate that under the energy constraints imposed to the nodes, G-TFT promotes cooperation if every node of the network conforms to it. The model in [2] provides an accurate description of the energetic constraint of a node, which is the main reason for a selfish behavior, but provides only high-level guidelines towards the design of a cooperation enforcement mechanism based on the G-TFT strategy. The main difference between the work presented in this paper and the research conducted in [2] is that in our model we take into account a more realistic scenario where the observations made by a node on her neighbors can be affected by errors.…”

“…The model in [2] provides an accurate description of the energetic constraint of a node, which is the main reason for a selfish behavior, but provides only high-level guidelines towards the design of a cooperation enforcement mechanism based on the G-TFT strategy. The main difference between the work presented in this paper and the research conducted in [2] is that in our model we take into account a more realistic scenario where the observations made by a node on her neighbors can be affected by errors. The monitoring mechanism is indeed the key feature of a cooperation strategy based on the observation of the opponent's move (such as G-TFT) and we believe that a more accurate description of how these observations are made is fundamental.…”

“…The research presented in [2], [3], [4] and in the second part of this paper, is based on non-cooperative game theory: even when multiple players are considered, the strategy selection phase is always driven by a node-centric perception of the game. As a result, the cooperation strategies obtained through the proposed models take into account only the payoffs obtained by a single player.…”