Mobile-Gateway Routing for Vehicular Networks 1

Development of vehicular ad hoc networks (VANETs) has drawn intensive attention in recent years. Designing routing protocols for vehicle-to-vehicle (V2V) communication in VANET may suffer from frequent link change and disconnection. Vehicleto-infrastructure (V2I) communication can overcome the challenge by relaying packets through the backbone network, but is limited to those areas where a RSU exists. In this paper, we present a position-based routing protocol, named mobile-gateway routing protocol (MGRP), for VANETs. The MGRP combines V2V and V2I communications, and utilizes certain vehicles as mobile gateways. Each mobile gateway connects with a base station through a 3G interface and communicates with other vehicles without the 3G interface through an IEEE 802.11 interface. Upon receiving packets from a vehicle, the mobile gateway forwards the packets to a gateway controller via the base station. The gateway controller then searches the position of the destination vehicle and determines a set of gateway vehicles close by the destination to forward the packets. Simulation results show that the MGRP can significantly improve the packet delivery ratios and reduce the transmission hop count. Keywordsvehicular ad hoc network; vehicle-to-vehicle; vehicle-to-infrastructure; position-based routing protocol;