Optimal D2D Cooperative Caching System In SDN Based Wireless Network.

The prosperity of data-enabled mobile devices and wireless-enabled data applications in today’s mobile ecosystem has fostered the rapid development of wireless content caching, which has recently been considered as an efficient way to mitigate the contradiction between huge amount of multimedia data traffic and limited wireless communication rate. In this paper, a software-defined network (SDN) caching system is proposed where the cache of every mobile device (MD) is divided into two partitions for caching files in different levels of popularity by different cache manners. The requested files of MDs can be obtained locally, through device to device (D2D) cooperation or cellular network. The proposed D2D cooperative caching strategy is optimized by maximizing the cache hit probability (CHPro) and we analyze the effect of the power consumption expectation (PCExp) on the strategy in the SDN based network. Simulation about the influence of cache splitting coefficient on CHPro and PCExp under different conditions, as well as the impact of file popularity order on caching probability when the cache splitting coefficient gets the optimal value reminds us to optimize CHPro and PCExp comprehensively, and we propose a method to solve the comprehensive optimization.