Towards Risk-Averse Edge Computing With Deep Reinforcement Learning

Recently, artificial intelligence paves the way for the development of smart services for people anytime and anywhere, which poses great challenges on accessing computing resources. Multi-access edge computing complements existing cloud computing infrastructure at the edge of the network, where mobile users can offload computationally intensive tasks of smart applications to edge servers that are in proximity to the users themselves. Existing offloading schemes mainly focus on selecting edge servers for each offloading task with the goal of optimizing the overall average latency. However, the solutions with the optimal overall average latency may be not the most suitable for all offloading tasks. There is still a possibility that offloading leads to an extreme case of ultra-high latency, which is not acceptable for latency-sensitive applications. To address this problem, we therefore introduce modern portfolio theory (MPT) to jointly consider the overall average latency and potential risks in optimal edge server selection. The task offloading problem is regarded as an investment portfolio with the objective of maximizing the ‘return’ while minimizing the risk. Combining MPT with deep reinforcement learning (DRL), we design two proximal policy optimization (PPO)-based task offloading algorithms to jointly optimize these two objectives. The algorithm computes a portfolio for each mobile user that enables the diversification of edge server selection, thereby minimizing the risk and the average latency. Extensive simulation results based on three real-world trace datasets show that our algorithms significantly outperform the state-of-the-art solutions and can reduce the overall average latency and the risk by 59% and 85% at most, respectively.