Token System Design for Autonomic Wireless Relay Networks

This paper proposes a novel framework for incentivizing self-interested transceivers operating in autonomic wireless networks to provide relaying services to other transceivers in exchange for tokens. Tokens represent a simple internal currency which can be used by the transceivers in a network to exchange services. Our emphasis in this paper is on developing optimal designs for the token system, which maximize the system efficiency, i.e. the probability that the relay transmission will be executed by transceivers whenever they are requested to provide such services. Particularly, we prove that the efficiency of the relay network heavily depends on issuing the proper amount of tokens rather than an arbitrary amount. First, we study the transceivers' optimal strategies (i.e. the strategies that maximize the transceivers' own utilities) using the formalism of repeated games. We prove that these strategies exhibit a simple threshold structure. We also prove that the threshold is unique given transmission costs. Second, we determine the optimal token amount which needs to be introduced in the relay system to maximize the overall relay network efficiency. This amount needs to be neither too small (since a too small amount leads to a small relaying service request probability) nor too large (since a too large amount leads to a small relaying service provision probability) and depends on the threshold strategy that the self-interested transceivers adopt. We subsequently develop an efficient algorithm which is able to determine, depending on the network characteristics, the threshold to be implemented by the optimal strategies and the optimal token amount. Finally, simulation results show the effectiveness of our token system design in providing incentives for cooperation among self-interested relays in autonomic wireless relay networks.