On the Feasibility of Using 802.11p for Communication of Electronic Toll Collection Systems

Abstract

In an 802.11p (the so-called DSRC) network, the WSMP protocol is used for the communication between OBU and RSU. Unlike a wired network, an 802.11p wireless network is prone to fading, shadowing, and interferences, which might result in high error rates. However, there is no reliability mechanism embedded in the WSMP protocol, which can become an important issue for mission-critical ITS applications such as ETC (Electronic Toll Collection). In this work, we develop a protocol on top of WSMP to build a reliable session for the message exchanges between RSU and OBU. Our protocol uses a timer-based mechanism for the message retransmission in the case of message losses. In this paper, we first describe the design of our session protocol and evaluate its performance for ETC communication in simulations. We then discuss the implementation of our protocol on the ITRI WAVE box and evaluate its effectiveness on real roads.