Group Strategyproof Multicast in Wireless Networks

Abstract-We study the dissemination of common information from a source to multiple nodes within a multihop wireless network, where nodes are equipped with uniform omnidirectional antennas and have a fixed cost per packet transmission. While many nodes may be interested in the dissemination service, their valuation or utility for such a service is usually private information. A desirable routing and charging mechanism encourages truthful utility reports from the nodes. We provide both negative and positive results toward such mechanism design. We show that in order to achieve the group strategyproof property, a compromise in routing optimality or budget-balance is inevitable. In particular, the fraction of optimal routing cost that can be recovered through node charges cannot be significantly higher than 1/2. To answer the question whether constant-ratio cost recovery is possible, we further apply a primal-dual schema to simultaneously build a routing solution and a cost-sharing scheme, and prove that the resulting mechanism is group strategyproof and guarantees 1/4-approximate cost recovery against an optimal routing scheme.