An optimized TCP for Internet access of vehicular ad hoc networks

Communication efficiency at the transport layer is of specific importance for ad hoe networks. Especially in vehicular ad hoc networks, vehicles will have a temporary and rather short-lived connectivity to the Internet, which has to be utilized efficiently. In this paper, we propose a TCP-based transport protocol called MCTP that is optimized for the Internet access in vehicular environments. Therefore, MCTP is combined with split performance enhancing proxy architectures, where a proxy separates the end-to-end TCP connection. This enables the deployment of optimized transport protocols while maintaining interoperability with TCP used in the Internet. For the evaluation, we emulated the communication characteristics of a "typical" vehicular scenario. This clearly shows the advantages of MCTP over traditional approaches; the overall data throughput is significantly higher when MCTP is used for communication between vehicle and proxy. The evaluation also emphasizes the usefulness of performance enhancing proxies in vehicular environments.