Energy- and Bandwidth-Efficient, QoS-Aware Edge Caching in Fog-Enhanced Radio Access Networks

The emerging video services are associated with stringent quality-of-service (QoS) requirements and place high bandwidth demands on the core networks. Edge caching can facilitate the stringent QoS demands while easing the bandwidth requirement from core networks. However, such schemes require on-field caching equipment, in which energy consumption is a function of cache utilization. Designing opportunistic caching strategies for energy efficiency is therefore essential in such schemes. This paper studies the possibilities for achieving high energy efficiency, QoS, and low bandwidth consumption from the core network, in an optically fronthauled fog-enhanced radio access network that implements edge caching. An analytical model for such a network has been derived to measure latency, bandwidth consumption, and cache utilization. It is deduced from the results that low latency (high QoS) and bandwidth consumption can be ensured in such schemes while reducing the energy consumption by up to 93%. The derived model allows to design caching strategies for addressing the trade-off between energy efficiency, QoS, and bandwidth efficiency.