Performance and Reliability Analysis of IEEE 802.11p Safety Communication in a Highway Environment

Vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications are gaining increasing importance in vehicular applications. Dedicated short-range communication (DSRC) is a fundamental set of short-to-medium-range communication channels and a set of protocols and standards that are specifically designed for V2V and V2I communications. IEEE 802.11p is a protocol that has been standardized as the medium access control (MAC) layer of the DSRC standard. Due to the highly dynamic topology and low delay constraints in vehicular ad hoc networks (VANETs), direct (or one-hop) broadcast on the control channel (CCH) is an effective approach to inform the neighborhood of safety-related messages. The 802.11p enhanced distributed channel access (EDCA) mechanism allows four access categories (ACs) in a station for applications with different priorities according to their criticalities for the vehicle´s safety. This paper focuses on the analysis of the 802.11p safety-critical broadcast on the CCH in a VANET environment and improves the existing work by taking several aspects into design consideration. Extensive performance evaluations based on the NS-2 simulator help to validate the accuracy of the proposed model and analyze the capabilities and limitations of the standard 802.11p broadcast on the CCH.