USV Bidirectional Data Completion Time Minimization in Multi-RIS-Assisted UAV-USV Cooperative MEC Network

Yangzhe Liao, Lin Liu, Yi Han, Yong Ma, Gabriel-Miro Muntean

Abstract: A potential approach to satisfy the emerging unmanned surface vehicle (USV) bidirectional tasks with time window constraints is to utilize a multi-reconfigurable intelligent surface (RIS)-assisted data transmission scheme, where fixed RIS and unmanned aerial vehicle (UAV)-carried RIS are cooperatively deployed. However, very few works have thoroughly explored this avenue due to its high mathematical complexity. This work proposes a multi-RIS-assisted UAV-USV cooperative mobile edge computing (MEC) network architecture and formulates an USV bidirectional task completion time minimization problem by jointly considering USV task execution parameters, UAV flight routes indicators, UAV hovering coordinates and multi-RIS phase shift vectors. The problem is then decomposed into three subproblems focusing on USV task execution optimization, joint UAV flight routes and hovering optimization and multi-RIS phase shift vector optimization, respectively. The paper introduces CHRISM, an innovative heuristic solution, which includes three algorithms to solve each of these optimization subproblems in the context of the proposed network architecture. The performance of CHRISM is tested in various scenarios and the results show that CHRISM can significantly decrease USVs bidirectional task execution time compared to alternative algorithms.

External IDs:doi:10.1109/tvt.2026.3656367