Joint Distributed Cache and Power Control in Haptic Communications: A Potential Game Approach

Since haptic communications have an extreme requirement for the latency performance, the overdue content delivery will decrease the application experience. In order to reduce the transmission delay, we try to construct a cache-enabled D2D-assisted content sharing framework, where the neighbouring helpers preset contents and adjust their transmission power to timely serve more requesters. In particular, we modify the existing definition of the “closest” friend and take the social relationship into account to measure the overall influence caused by available neighboring helpers. However, such cooperation consumes the storage space and energy of the helpers, and accordingly, we introduce blockchain technology to propose an effective incentive mechanism where the helpers act as consensus users of blockchain and obtain the reward, i.e., the allocated computing power by the base station (BS), by contributing their local resources. Guided by this, the benefit of each helper is defined as a tradeoff of the reward and overheads. Meanwhile, we formulate the multi-user content delivery problem with the goal of maximizing the global benefits as the multi-user content delivery game. Then, we prove that the proposed game is an exact potential game (EPG) with at least one pure-strategy Nash equilibrium (NE). Meanwhile, the context-aware content delivery based concurrent better reply (CCDCBR) algorithm is proposed to achieve a desirable solution. Finally, simulation results verify the validity of the proposed game model as well as the proposed algorithm.