Contract Theory and Stackelberg-Game-Based Storage Resource Allocation in Edge Caching Systems

With the booming of Internet of Things (IoT), a content provider (CP) traditionally supported by the storage resources of a network service provider (NSP) can provide content services through the resources of IoT devices to significantly reduce the service latency. The CP, NSP, and IoT devices constitute an edge caching system, and it is crucial to efficiently utilize the storage resources in the system. Most existing studies ignore the idle storage resources of IoT devices. The few studies that consider the storage resources of IoT devices either are based on the assumption of complete information, or only utilize the storage resources of part of the IoT devices. In this article, we propose a contract theory and Stackelberg game-based storage resource allocation method to effectively utilize the storage resources in edge caching systems under information asymmetry. The interaction between the CP and the IoT is formalized as a contract design problem, and the interaction between the NSP and the CP is formulated as a two-stage Stackelberg game with a single leader and a single follower. We analyze the constraints in contract design and the Nash equilibrium of the Stackelberg game. We also propose a golden section search-based optimal contract design and pricing (GSSCP) algorithm to obtain the optimal contract of the CP and optimal price of the NSP storage resources. Simulation results demonstrate that the proposed method can make effective use of the storage resources and improve the CP utility in edge caching systems under information asymmetry.