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计算机工程 ›› 2025, Vol. 51 ›› Issue (9): 49-58. doi: 10.19678/j.issn.1000-3428.0069784

• AI算力赋能的车载边缘计算 • 上一篇    下一篇

面向卫星车载MEC网络的协同计算卸载方法

赵季红1,2, 臧若雨1,*(), 刘振1   

  1. 1. 西安邮电大学通信与信息工程学院, 陕西 西安 710121
    2. 西安交通大学电子信息工程学院, 陕西 西安 710049
  • 收稿日期:2024-04-25 修回日期:2024-07-10 出版日期:2025-09-15 发布日期:2024-08-20
  • 通讯作者: 臧若雨
  • 基金资助:
    国家重点研发计划重点专项项目(2018YFB1800305)

Collaborative Computation Offloading Method for Satellite Vehicle-Mounted Mobile Edge Computing Networks

ZHAO Jihong1,2, ZANG Ruoyu1,*(), LIU Zhen1   

  1. 1. School of Communication and Information Engineering, Xi'an University of Post and Telecommunications, Xi'an 710121, Shaanxi, China
    2. School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, China
  • Received:2024-04-25 Revised:2024-07-10 Online:2025-09-15 Published:2024-08-20
  • Contact: ZANG Ruoyu

摘要:

车联网(IoV)环境中任务的动态性提高了实时计算卸载的复杂性。针对IoV场景中地面网络覆盖受限导致的实时任务难以及时完成的问题,提出一种面向卫星车载移动边缘计算网络(SVMECN)的协同计算卸载方法。首先,构建卫星与地面间的几何关系模型,计算设备与卫星、地面网关与卫星之间的传输速率,并基于该模型计算任务处理时延,模型充分考虑任务的实时性,动态调整卫星移动对地面数据传输的影响,通过卫星与地面网关的协作处理来满足车载应用对时延的要求;其次,提出一种基于指针注意力机制和Actor-Critic(ST-PART)的协同计算卸载算法,根据任务的实时性动态调整任务优先级,按照优先级顺序对任务进行计算卸载,并在不同计算节点之间动态选择和协同处理任务,以最小化任务处理时延。在SVMECN中对所提算法进行仿真,结果显示,与传统的启发式算法相比,所提算法在提高运行效率方面表现突出。实验和分析结果表明,所提算法在满足任务实时性需求的同时能够显著降低任务处理时延,与地面和卫星未协同的算法相比,该算法能够降低2.35%~68.68%的时延成本。

关键词: 星地协同网络, 移动边缘计算, 指针注意力, 强化学习, 计算卸载

Abstract:

The dynamic nature of tasks in Internet of Vehicles (IoV) environments increases the complexity of real-time computational offloading. To address the difficulty of completing real-time tasks in a timely manner owing to limited terrestrial network coverage in IoV scenarios, this study proposes a collaborative computational offloading approach for Satellite Vehicular Mobile Edge Computing Networks (SVMECN). First, a geometric relationship model between satellites and the ground is constructed to calculate the transmission rates between devices and satellites, as well as between terrestrial gateways and satellites. The task processing delay is computed based on this model. The model fully considers the real-time nature of tasks and dynamically adjusts for the impact of satellite movement on terrestrial data transmission. Through collaborative processing between satellites and terrestrial gateways, the latency requirements of in-vehicle applications are met. Second, the study proposes a collaborative computational offloading algorithm based on Pointer Attention Mechanism and Actor-Critic (ST-PART). This algorithm dynamically adjusts task priorities according to their real-time nature, offloads tasks for computation in order of priority, and dynamically selects and collaboratively processes tasks among different computing nodes to minimize task processing delays. The proposed algorithm is simulated in an SVMECN environment. Compared with traditional heuristic algorithms, the proposed algorithm improves operational efficiency. Experimental and analytical results indicate that the proposed algorithm can significantly reduce task processing delays while meeting the real-time requirements of tasks. Compared with algorithms without collaboration between terrestrial and satellite components, the proposed algorithm can reduce latency costs by 2.35%-68.68%.

Key words: collaborative satellite-terrestrial network, Mobile Edge Computing (MEC), pointer attention, Reinforcement Learning (RL), computation offloading