Cost-aware resource allocation for optimization of energy efficiency in fog radio access networks

Taking full advantage of centralized cooperation and edge caching, fog radio access network has been considered as a promising paradigm to provide high spectral efficiency and energy efficiency. However, the overheads on fronthaul transmission and content caching also significantly affect the affordability, which makes it an increasingly urgent problem to achieve the performance improvement with reasonable overheads. In this paper, the economical energy efficiency (E³) metric is adopted to comprehensively consider the impacts on different aspects. Under the constraints of maximum transmitting power, cache status, and fronthaul capacity, a resource allocation problem is formulated, in which throughput, energy consumption, as well as cost on fronthaul transmission and content caching are jointly considered. The problem is solved using fractional programming, weighted minimum mean square error approach, and greedy algorithm, and an adaptive transmitting method selection algorithm is proposed. The simulation results demonstrate the effectiveness and gains of the proposed algorithm, and the corresponding key factors impacting on E³ are accordingly analyzed and evaluated.