Game-based incentive mechanism for enabling edge video caching over passive optical networks

With the ever-increasing mobile video traffic, edge caching enabled passive optical networks (PONs), where storages are deployed on optical network units (ONUs), are becoming a desirable back-end for mobile backhaul (MBH). By caching videos on ONUs, video requests generated in MBH can be efficiently accommodated. Thus, many previous works focus on leveraging the caching capabilities of ONUs to maximize the video cache-hit ratio. However, it is largely ignored how to stimulate individual ONUs to contribute their storages for caching videos. In this paper, we propose a game-based incentive mechanism through which the content provider (CP) rewards ONUs for their storage-contributions. We firstly formulate a two-level Stackelberg game to capture the interaction between the CP and ONUs. At the first level, the CP determines rewarding policy to maximize its utility. At the second level, ONUs react with the amount of provided storages with the aim to cooperatively maximize the social utility or competitively maximize their respective utilities, and thereby two sub-games are further modeled to depict the cooperation and competition among ONUs. We then give the specific strategies of cooperative ONUs and competitive ONUs, respectively. We also show the existence of an equilibrium in the formulated Stackelberg game. The performance of the proposed incentive scheme is finally evaluated by simulations.