A caching-based incentive mechanism for cooperative data offloading

The ever-increasing demand for multimedia contents has imposed severe traffic overload pressure on mobile network operators (MNOs). Cooperative data offloading is a promising approach to alleviate the traffic congestion, which leverages the device-to-device (D2D) communications among mobile users. However, mobile users may not be obligated to participate in cooperative data offloading, since it will involve additional costs such as storage, bandwidth and battery energy. In this paper, we propose a centralized caching-based incentive mechanism, which stimulates mobile users to cache and forward contents for MNOs. First, we formulate a caching user selection and content allocation problem by considering the service coverages of mobile users and the content popularity in cellular networks. Due to the NP-hardness of the problem, we introduce a heuristic algorithm with polynomial time complexity. Second, we propose a payment determination algorithm, which satisfies the properties of individual rationality and truthfulness. Finally, simulations are carried out to evaluate the effectiveness of the proposed incentive mechanism. Compared with conventional caching schemes, our coverage-aware caching strategy achieves a better performance in terms of the utility of both MNOs and mobile users.