Impact of User Mobility on D2D Caching Networks
Sameh Hosny, Atilla Eryılmaz, Hesham El Gamal · 2016
The mismatch between user demand and service supply creates a congestion in mobile wireless networks. The literature has a strong evidence that user behavior is highly predictable. Taking advantage of user demand predictability allows the carrier to apply proactive caching in order to smooth out the network load. Moreover, harnessing the information about user mobility enhances carrier's caching decision and minimizes the incurred service cost. The information about users' trajectories allows the carrier to predict their availability in some popular locations which experience high demand. Finding an optimal caching strategy alleviates the network congestion in these locations and improves the overall network performance. We introduce a system model where the carrier takes a decision to proactively cache some of the requested data items in users' devices. Users are equipped with D2D communication which is used to share cached data items between them in these popular locations. Users get reward to compensate their memory usage and battery consumption. Although caching helps users to save some of their payment, this reward promotes them to participate in the proposed model. We establish a lower bound on the proactive service cost which yields some insights on how user demand and mobility statistics affect carrier's caching decision.