Efficient token circulation strategies against misers in device-to-device relay using token-based incentive mechanisms

Abstract

Device-to-device (D2D) relay not only broadens the service coverage of a base station (BS) but also raises network capacity. When the channel quality of a user equipment (UE) is not good, it requests another UE to relay its data from the BS. Since many UEs are owned by self-interested users, token-based incentive (TBI) mechanisms allow UEs selling and buying relay services by exchanging tokens, thereby pricking UEs on to act as relay nodes. However, such mechanisms are vulnerable to the miser problem, where malicious UEs keep collecting tokens from others but never spend tokens. Eventually, negotiable tokens will gradually decrease, so more and more UEs have very few tokens to buy relay services, which restrains D2D relay. To conquer the miser problem, this paper proposes three token circulation strategies, which tax UEs and redistribute the taxed tokens to those UEs in need. Thus, misers can be prevented from hoarding tokens and breaking a TBI mechanism. The proposed strategies need not add tokens to the network, so they will not cause inflation of tokens. Simulation results show that these strategies can keep high D2D throughput with the existence of misers, which protects TBI mechanisms and promotes the performance of D2D relay.