Improving Resource Allocation for eMBB and URLLC: Caching at the Edge

This paper investigates the problem of caching placement and wireless backhaul resource allocation for enhanced mobile broadband (eMBB) and ultra-reliable low latency communications (URLLC) coexistence. Different from existing works which focus on the resource allocation for eMBB and URLLC in the access but ignore the backhaul traffic, this paper considers that the backhaul traffic can be alleviated by caching eMBB contents at the edge, such that more transmission resources can be released for scheduling URLLC traffic in wireless backhaul networks. We first propose an upper confidence bound (UCB)-based caching algorithm to reduce eMBB traffic in the backhaul, resulting in more backhaul resources that can be punctured by URLLC traffic. To minimize the URLLC delay while ensuring eMBB throughput, a greedy resource allocation algorithm is then proposed to allow URLLC traffic to puncture resources of eMBB traffic in the backhaul as many as possible. Simulation results demonstrate the superior performance of the proposed algorithms in terms of URLLC delay.