With the growing interest in autonomous driving, constant connectivity for vehicles is becoming essential to enable the complete knowledge of the surrounding area, transmit and receive data that is crucial for the autonomous control. The vehicle mobility results in frequent service interruptions, and therefore, seamless handovers are required to mitigate this problem. Several IP-based solutions have been proposed in the literature, but they require tunneling approaches, which present excessive signaling and data overhead, service delay, and packet loss. One of these approaches, the NEMO-enabled Proxy Mobile IPv6 (N-PMIPv6) architecture, supports transparent handovers and simultaneous multi-homing, but at the cost of a high complexity and network overhead.

This work explores the flexibility of Software Defined Networks (SDNs) in the management of a Vehicular Ad-hoc NETwork (VANET). In particular, the SDN concept is used to provide a seamless horizontal handover for the vehicle and its end-users. Two different SDN architectures are proposed, evaluating the impact of the depth of the softwarization environment. Real vehicular hardware and emulated mobility scenarios are used in the evaluation process where different application services are exploited. Results show that the lower complexity of the SDN solution allows for a better performance during a handover in a VANET, in terms of delays, packet losses and network overhead, making it seamless for the vehicles and its users.

随着人们对自动驾驶的兴趣日益浓厚，车辆的持续连接对于实现对周围区域的全面了解，发送和接收对于自动控制至关重要的数据变得至关重要。车辆的机动性导致频繁的服务中断，因此，需要无缝切换以减轻该问题。文献中已经提出了几种基于IP的解决方案，但是它们需要隧道方法，这会带来过多的信令和数据开销，服务延迟以及数据包丢失。这些方法之一是启用NEMO的代理移动IPv6（N-PMIPv6）体系结构，支持透明切换和同时进行的多宿主，但要付出高昂的复杂性和网络开销的代价。

这项工作探讨了在车辆专用网络（VANET）的管理中软件定义网络（SDN）的灵活性。特别是，SDN概念用于为车辆及其最终用户提供无缝的水平切换。提出了两种不同的SDN架构，以评估软化环境深度的影响。在评估过程中使用了实际的车辆硬件和模拟的移动方案，在其中利用了不同的应用程序服务。结果表明，SDN解决方案的较低复杂性在延迟，数据包丢失和网络开销方面，在VANET切换过程中可提供更好的性能，从而使其对于车辆及其用户而言是无缝的。