Abstract—Device-to-Device (D2D) content sharing is an excellent solution to offload the traffic from the core 5G networks and backhaul links. Caching the most popular files at the network edge and in users’ devices to support user proximity services in 5G helps to offload traffic in the core network and increases the cache hit probability. D2D communication in 5G can be utilized to share the cached files between a pair of devices with a minimal involvement from the base station. This paper presents a collaborative content caching scheme with the primary objective to maximize the overall system offloading gain and the cache hit probability in downloading the popular file contents. The proposed system model exploits the social-networking concept within the WiFi Direct radio range, assuming the cell structure present in a densely populated area such as a university campus or an auditorium. The performance of the proposed cache scheme is evaluated through extensive simulations taking into consideration the device mobility and disconnection, and the results are presented.