Joint 3C Scheduling with Coordinated Multi-point Transmission

In this paper, the joint scheduling of communication-computation-caching (3C) is studied in a fog radio access network (F-RAN) to accommodate differentiated quality-of-service (QoS) requirements. A representative application of adaptive bit-rate (ABR) content streaming deployed in the 3C-enabled F-RAN is considered, by allowing multiple fog access points (F-APs) to jointly provide services to users with coordinated multi-point (CoMP) transmission. Minimization of the average download time is considered, within which the sequential arrivals and processing of users' requests are modeled by a multi-class processor queue. The proposed problem corresponds to a joint optimization on the cache content placement at each F-AP and the collaborative content provision among multiple F-APs using CoMP. To solve this mixed integer nonlinear programming (MINLP) problem, an alternating optimization framework is proposed, in which the genetic algorithm (GA) is used to solve discrete variables and the alternating direction method of multipliers (ADMM) is used to solve continuous variables. Simulation results demonstrate that the traffic load can be better balanced through CoMP transmission, thus effectively reducing average latency. By exploiting the synergy between 3C, the network performance can be significantly improved with a joint coordinated allocation of 3C resources.