User Cooperation in Wireless Powered Transfer-Mobile Edge Computing (WPT-MEC) Networks: A Comprehensive Review

Abstract

User cooperation has emerged as an effective way to improve the efficiency and sustainability of Wireless Powered Transfer-Mobile Edge Computing networks. The relaying, task forwarding, and resource-sharing-based cooperative schemes enhance system efficiency by alleviating energy imbalance and computation bottleneck problems in heterogeneous users. Finally, it discusses various next-generation cooperative methods: UAV-based transmission, integration aided by RIS and STAR-RIS, NOMA-based multi-access, and the harvest-then-cooperate protocol. Optimization techniques ranging from convex programming, deep reinforcement learning, matching theory, and game-theoretic models have been exhaustively studied to optimize for efficient smart resource allocation with network dynamics. Emerging frameworks involve key trade-offs in energy efficiency, latency, fairness, and scalability. Moreover, this paper presents open research issues and pinpoints some of the key limitations in current designs. It is concluded that user cooperation significantly enhances the functionality and fairness of WPT-MEC systems, making them more viable for large-scale, heterogeneous deployments. Also, continued interdisciplinary research combining wireless communication, machine learning, distributed systems, and cybersecurity is necessary to unlock the full potential of cooperative edge computing in 6G and smart edge computing era.