Collusion-resistant repeated double auctions for relay assignment in cooperative networks

Cooperative communication effectively enhances the channel capacity of wireless networks by allowing some single-antenna nodes to relay data for other nodes. In such a communication scheme, choosing appropriate relay nodes is critical to maximize the overall network performance. In this paper, we consider the assignment problem of relay nodes in a cooperative wireless network, where physical relay infrastructures and relay supporting services (relay assignment) are independently operated by different selfish entities, each of which is driven by its own benefit. We first formulate the problem as a repeated double auction by taking into account the benefits of all entities in the system. That is, we consider a system consisting of a set of source-to-destination pairs, relay nodes, group agents, and the auctioneer, where source nodes are grouped into different groups and each group is represented by a group agent. The source nodes and group agents seek opportunities to maximize their own benefits through untruthful bidding, colluding with each other, and so on. We then show that these behaviors will jeopardize the social benefit of all entities in the system. To mitigate the effect of such behaviors, we devise a truthful repeated double auction that is able to bound the collusion probability of each entity. We finally conduct experiments by simulations to evaluate the performance of the proposed auction mechanism. Empirical results show that the proposed auction is effective in collusion-resistance with bounded collusion probabilities. To our best knowledge, this is the first auction mechanism for relay assignment in wireless networks that is truthful, collusion-resistant, budget-balance and individual-rational.