A Mobile Infrastructure Based VANET Routing Protocol in the Urban Environment

The vehicular ad hoc network (VANET) is an emerging new technology. Developing multi-hop routing protocols for urban VANETs is a challenging task due to many factors such as frequent network disconnections. Many VANET routing protocols use a carry-and-forward mechanism to deal with the challenge. However, this mechanism introduces a large packet delay, which might be unacceptable for some applications. In this paper, we first analyze the unique features of urban VANET that vehicles have different types, and move like clusters due to the influence of traffic lights. So, the concept of using buses as the mobile infrastructure to improve the network connectivity is proposed. We also develop a novel routing protocol named MIBR (Mobile Infrastructure Based VANET Routing Protocol). This protocol makes full use of the buses, making them a key component in route selecting and packet forwarding. Simulation results show significant performance improvement in terms of packet delivery ratio and throughput.