Energy Prioritized Caching for Cellular D2D Networks

Multimedia content transmission heavily taxes network resources and puts a significant burden on wireless systems in terms of capacity and energy consumption. In this context, device-to-device (D2D) paradigm has a utilitarian value to alleviate the network burden by utilizing short-range transmissions with less energy cost. For the realization of proper D2D networking, caching in devices is essential. Additionally, caching needs to operate efficiently with the aim of realizing network-wide energy improvements. To this end, we study multimedia caching in cellular D2D networks and propose an energy prioritized D2D caching (EPDC) algorithm in this work. We also investigate the optimal caching policy in that system setting. The impact of device capacity and D2D transmission range on energy consumption is studied by focusing on different operation modes such as D2D and base station transmissions. According to the simulation results, EPDC algorithm has substantial energy-efficiency gains over the commonly utilized Least Recently Used (LRU) algorithm and content-based caching algorithms PDC and SXO. For larger D2D transmission ranges, this improvement becomes more evident.