Dynamic Resource Allocation in High-Speed Railway Fog Radio Access Networks with Delay Constraint

Abstract

By applying caching resource at the remote radio heads (RRHs), the fog radio access network (Fog-RAN) has been considered as an promising wireless architecture in the future network to reduce the transmission delay and release the heavy burden of backhaul link for huge data delivery. In this paper, we propose to use the Fog-RAN to assist the data transmission in the high-speed railway scenario. In specific, we investigate the dynamic resource allocation in high-speed railway Fog-RAN systems by considering the delay constraint. The instantaneous power allocation at the RRHs and the instantaneous content delivery rate over the backhaul links are jointly optimized with an aim to minimize the total power consumed at the RRHs and over the backhaul links. An alternating optimization (AO) approach is used to find solutions of the instantaneous power and instantaneous content delivery rate in two separate subproblems. The closed-form solutions are derived in two subproblems under certain special conditions. Simulation results demonstrate that the proposed dynamic resource allocation is significantly superior to the constant resource allocation scheme.