Caching Strategy Based on Data Freshness with Helpers in D2D Wireless Network

Recently, device-to-device (D2D) wireless network has become a research hotspot, which can reduce the traffic through the network. In the network, by caching popular files in the memory of end users, the users can obtain requested contents with lower energy consumption. Helper is defined as a dedicated device with large caching capacity, with helpers in a D2D wireless networks, the performance can be significantly improved. However, the data freshness has not been considered in previous works using helpers in D2D wireless network. In this paper, taking data freshness into consideration and aiming at reducing energy consumption, the access route for user content requests is formulated and a content access and updating strategy with helpers is proposed. In this strategy, a helper can improve service quality for adjacent users with low energy consumption and high data freshness. Simulation results demonstrate that our proposed strategy can reduce the system energy consumption while ensuring the content freshness.