车载边缘计算网络中基于MAB的动态任务卸载方案研究

Study on Dynamic Task Offloading Scheme Based on MAB in Vehicular Edge Computing Network

将移动边缘计算技术应用到车载网络所形成的车载边缘计算系统,能够通过任务卸载为其他移动设备提供计算服务。然而,由于车载设备的移动性,导致了车载任务卸载环境是动态变化和不确定的,具有快速变化的网络拓扑、无线信道状态和计算负载,这些不确定性让任务卸载过程非理想化。针对这些不确定性,考虑将MEC服务器的计算资源下沉到车载设备,研究车辆之间的任务卸载,并提出了一种解决方案,使得车辆能够在未知状态信息的前提下学习周围车辆的服务性能并卸载任务。基于多臂老虎机框架,设计了一种二阶探索的强化学习算法,以最大化用户平均卸载回报,并且在一个卸载阶段结束后提出了一种服务集更新方式,以保证用户的服务质量。仿真结果表明,与现有的基于置信上限的算法相比,所提方案下的卸载回报提高了约34%。

The mobile edge computing system formed by applying mobile edge computing technology to Internet of Vehicles can provide computing services for other mobile devices through task offloading.However,due to the mobility of vehicle equipment,the environment of vehicular task offloading is dynamic and uncertain,with rapidly changing network topology,wireless channel state and computing load.These uncertainties make the task offloading process non-idealized.In view of these uncertainties,the computing resources of the MEC server are sunk into the vehicle equipment to study the task offloading between vehicles,and a solution is proposed to enable vehicles to learn the service performance of surrounding vehicles and offload tasks without knowing the status information.Based on the multi-arm bandits framework,a second-order exploration reinforcement learning algorithm is designed to maximize the average offloading return of users,and a service set update method is proposed after the end of an offloading phase to ensure the quality of service for users.Simulation results show that,compared with the existing algorithm based on upper confidence bound,the offloading return under the proposed scheme is improved by about 34%.