Bandwidth and Task Flow Control in Stochastic Relay-Assisted MEC

This letter studies stochastic Multi-hop Mobile Edge Computing (MMEC), where a Relay Node (RN) receives tasks from the users and randomly decides to assign them to its own computing server or to offload them to one of the multiple Higher-level computing Nodes (HNs). We take into account the waiting times in the computation and transmission queues and present the system Average Response Time (ART) in terms of offloading probabilities and links’ bandwidths. Based on that, we aim at minimizing the system ART by joint optimization of the task flow distribution among the RN/HNs and the bandwidth allocation among the links. We analyze the formulated problem and prove it is multi-convex. Moreover, we derive the closed-form expressions for the links’ bandwidths when the offloading probabilities are fixed, and based on the presented analysis and insights, we propose effective solution methods. Numerical results reveal the promising performance of the proposed methods in efficient use of the resources and reduction of the ART.