The traditional Vehicular ad hoc Network (VANET) data offloading was enabled when a vehicle is inside the signal coverage of an IEEE 802.11p Road Side Unit (RSU) or Wi Fi Access Point (AP). This work proposed to have the VANET data offloading from cellular network's Base Station (BS) to IEEE 802.11p RSU or Wi Fi AP using the multiple hop vehicular to vehicular (V2V) path that can connect with the ahead or the rear RSU/AP to increase the possibility of VANET data offloading. The aforementioned scenario is called V2V2I VANET offloading in this work. The key point of the proposed V2V2I VANET offloading is how to find the multiple hop V2V path that can connect the ahead/rear RSU/AP from the source vehicle to have the VANET data offloading as early as possible and as long as possible. This work proposed the Mobile Edge Computing (MEC)-based method to tackle related issues for the V2V2I VANET offloading. Based on MEC's centralized computing paradigm, each vehicle reports its context to the MEC server periodically. Since a multiple hop V2V path becomes more unstable when the path has a bigger number of hops, the MEC server gathers reported contexts from vehicles and then uses the proposed k-hop-limited Offloading Time-based V2V2I offloading path Selection (k-hop-limited OTS) method to find the suitable V2V2I VANET offloading path for vehicle V before (after) V entering into (has left) the signal coverage of the ahead (rear) RSU/AP. The performance analysis shown that the proposed MEC-based V2V2I VANET offloading method outperforms the traditional V2I VANET offloading method in different vehicle density's situations.

当车辆位于IEEE 802.11p路边单元（RSU）或Wi Fi接入点（AP）的信号覆盖范围内时，启用传统的车载自组织网络（VANET）数据卸载。这项工作建议使用多跳车到车（V2V）路径将VANET数据从蜂窝网络的基站（BS）卸载到IEEE 802.11p RSU或Wi Fi AP，该路径可以与前面或后面的RSU / AP连接。增加了VANET数据卸载的可能性。在此工作中，上述方案称为V2V2I VANET卸载。提议的V2V2I VANET卸载的关键是如何找到可以连接源车辆的前/后RSU / AP的多跳V2V路径，以尽早和尽可能长地卸载VANET数据。这项工作提出了基于移动边缘计算（MEC）的方法来解决V2V2I VANET卸载的相关问题。基于MEC的集中式计算范例，每辆车都会定期向MEC服务器报告其上下文。由于多跳V2V路径在跳数较大时会变得更加不稳定，因此MEC服务器会从车辆收集报告的上下文，然后使用建议的基于k跳限制的基于卸载时间的V2V2I卸载路径选择（k-hop-有限OTS）方法，以在V进入（左）前（后）RSU / AP的信号覆盖范围之前（之后）为车辆V找到合适的V2V2I VANET卸载路径。性能分析表明，在不同车辆密度情况下，基于MEC的V2V2I VANET卸载方法优于传统的V2I VANET卸载方法。