The increasing number of connected and automated vehicles has led to a sharp increase in the demand for network access of moving vehicles. Although 5G networks support terminals with high mobility, the traffic load is too heavy to bear if all the vehicles have a large amount of data for transmission. Therefore, IEEE 802.11-based wireless network is a complementary offload solution to provide high-speed network access for vehicles with low cost, easy deployment and high scalability. However, frequent network handover of moving vehicles between multiple roadside access points (APs) results in network performance degradation, which is one of the challenges in vehicular communications. In this paper, we propose a framework (referred to as ASAP) based on the up-to-date IEEE 802.11ax standard to provide moving vehicles with seamless handover between multiple APs. By leveraging the high efficiency (HE) sounding protocol of IEEE 802.11ax, each AP is capable to monitor the current location of moving vehicles in real time. In addition, a mechanism is also proposed for AP uplink/downlink transmissions through collaboration between the APs and the backbone network to achieve seamless handover for moving vehicles. Since ASAP is based on IEEE 802.11ax, the compatible security scheme such as IEEE 802.11i can be applied to ASAP for security enhancement. The proposed solution does not require any modification on the user terminals, making it possible to be implemented in practice. Extensive simulations show that ASAP significantly reduces the network handover delay to microsecond level, and improves network throughput up to 59% compared with the state-of-the-art methods.

中文翻译：

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ASAP：基于 IEEE 802.11ax 的移动车辆无缝接入点切换


联网和自动驾驶车辆数量的不断增加导致移动车辆的网络接入需求急剧增加。虽然5G网络支持高移动性的终端，但如果所有车辆都有大量数据需要传输，那么流量负载就难以承受。因此，基于IEEE 802.11的无线网络是一种互补的卸载解决方案，可为车辆提供低成本、易于部署和高可扩展性的高速网络接入。然而，移动车辆在多个路边接入点（AP）之间频繁的网络切换会导致网络性能下降，这是车辆通信的挑战之一。在本文中，我们提出了一种基于最新IEEE 802.11ax标准的框架（称为ASAP），为移动车辆提供多个AP之间的无缝切换。通过利用 IEEE 802.11ax 的高效 (HE) 探测协议，每个 AP 都能够实时监控移动车辆的当前位置。此外，还提出了一种通过AP与骨干网协作进行AP上下行传输的机制，实现移动车辆的无缝切换。由于ASAP基于IEEE 802.11ax，因此可以将IEEE 802.11i等兼容的安全方案应用于ASAP以增强安全性。所提出的解决方案不需要对用户终端进行任何修改，使得可以在实践中实现。大量的仿真表明，与最先进的方法相比，ASAP 显着地将网络切换延迟降低到微秒级，并将网络吞吐量提高了 59%。