论文标题
基于异步和深度增强学习的车辆边缘计算中的流动性合作缓存
Mobility-Aware Cooperative Caching in Vehicular Edge Computing Based on Asynchronous Federated and Deep Reinforcement Learning
论文作者
论文摘要
车辆边缘计算(VEC)可以在网络边缘的不同RSU中缓存内容,以支持实时车辆应用。在VEC中,由于车辆的高运动特性,有必要提前缓存用户数据,并为车辆用户学习最流行,最有趣的内容。由于用户数据通常包含隐私信息,因此用户不愿与他人共享其数据。为了解决这个问题,传统的联合学习(FL)需要通过汇总所有用户的本地模型来保护用户的隐私来同步更新全局模型。但是,车辆可能在实现本地模型培训之前经常将其驶离VEC的覆盖范围,因此无法按预期上传本地型号,这将降低全球模型的准确性。此外,本地RSU的缓存能力有限,并且流行内容是多种多样的,因此预测的流行内容的大小通常超过本地RSU的缓存能力。因此,在考虑内容传输延迟的同时,VEC应在不同的RSU中缓存预测的流行内容。在本文中,我们考虑了车辆的流动性,并提出了基于联合和深度强化学习(CAFR)的VEC中的合作缓存计划(CAFR)。我们首先考虑车辆的移动性,并提出一种异步FL算法以获得准确的全局模型,然后提出一种算法来预测基于全球模型的流行内容。此外,我们考虑了车辆的移动性,并提出了深入的强化学习算法,以获取预测流行内容的最佳合作缓存位置,以优化内容传输延迟。广泛的实验结果表明,CAFR方案的表现优于其他基线缓存方案。
The vehicular edge computing (VEC) can cache contents in different RSUs at the network edge to support the real-time vehicular applications. In VEC, owing to the high-mobility characteristics of vehicles, it is necessary to cache the user data in advance and learn the most popular and interesting contents for vehicular users. Since user data usually contains privacy information, users are reluctant to share their data with others. To solve this problem, traditional federated learning (FL) needs to update the global model synchronously through aggregating all users' local models to protect users' privacy. However, vehicles may frequently drive out of the coverage area of the VEC before they achieve their local model trainings and thus the local models cannot be uploaded as expected, which would reduce the accuracy of the global model. In addition, the caching capacity of the local RSU is limited and the popular contents are diverse, thus the size of the predicted popular contents usually exceeds the cache capacity of the local RSU. Hence, the VEC should cache the predicted popular contents in different RSUs while considering the content transmission delay. In this paper, we consider the mobility of vehicles and propose a cooperative Caching scheme in the VEC based on Asynchronous Federated and deep Reinforcement learning (CAFR). We first consider the mobility of vehicles and propose an asynchronous FL algorithm to obtain an accurate global model, and then propose an algorithm to predict the popular contents based on the global model. In addition, we consider the mobility of vehicles and propose a deep reinforcement learning algorithm to obtain the optimal cooperative caching location for the predicted popular contents in order to optimize the content transmission delay. Extensive experimental results have demonstrated that the CAFR scheme outperforms other baseline caching schemes.