An Optimal Incentive Mechanism for Blockchain-enabled Content Caching in Device-to-Device Communication

Cache-enabled device-to-device (D2D) communication is a promising approach to minimize data traffic and reduce communication costs and extra resource consumption. However, mobile user equipments (MUEs) have resource scarcity problems for storage, computation capacity, and battery lifetime. Due to these limited resources among untrusted MUEs, it becomes challenging to keep large content caches, maintain service quality, and provide secure transaction exchanges in D2D communication. Thus, Blockchain-enabled D2D content caching (BDCC) has recently become a new approach for caching popular content locally and sharing it with other MUEs securely and efficiently in a decentralized manner. Nevertheless, the existing BDCC system lacks an optimal incentive mechanism that motivates content providers (CPs) and content requestors (CRs) to maximize profit and utility. Hence, to address these problems, we introduce an efficient pricing-based incentive scheme that uses a two-stage Stackelberg game to allow the CPs and CRs to adjust the optimal strategy while maximizing their profit continually. Finally, the simulation results show that the proposed incentive scheme outperforms the baseline schemes in terms of the utility of CPs and CRs and the cache hit and miss ratio of the BDCC system.