Abstract

In the commercial caching system, both Infrastructure Provider (InP), who owns the infrastructure and wireless network resource and Service Providers (SPs), who provide service to its users based on the virtual resource provided by the InP, are beneficial in leasing and renting the cache space. By partitioning the cache space at the BS into slices and leasing each partition to the SPs, the InP can receive a payment. Meanwhile, the SPs can serve their users with faster download service with local caching. However, both SPs and InP are selfish and want to maximize their own benefits. In addition, in practice, there is asymmetric information between SPs and InP. Thus, some SPs may declare inaccurate private information to get more cache space or less payment. To deal with these problems, in this paper, we propose an incentive mechanism based on contract theory, in which the InP, the employer, who designs and offers contracts to SPs, the employees. In particular, SPs are specified into types based on their valuation parameters and request rates. Different from the traditional contract model with two feasible contract conditions, we impose cache capacity constraints, which induces the interaction among SPs and makes the contract design more complicated. We propose an algorithm that achieves the optimal contract so that the InP can motivate SPs to participate into renting caching space while maximize its utility. Simulation results show that the proposed approach not only ensures no SP has incentive to select another contract but also outperforms the baseline allocation algorithm.