Scalable Cross-Layer Wireless Access Control Using Multi-Carrier Burst Contention

The increasing demand for wireless access in vehicular environments (WAVE) supporting a wide range of applications such as traffic safety, surveying, infotainment etc., makes robust channel access schemes a high priority. The presence of selective fading, variable topologies, high density of nodes and feasibility issues represent important challenges in vehicular networks. We present Multi-Carrier Burst Contention, a cross-layer protocol based on a contention scheme that spans both time and frequency domains, employing short and unmodulated energy bursts and a randomized and recursive node-elimination mechanism in order to resolve collisions. It can overcome many of the vehicular environment challenges and provide desirable WAVE features such as scalability, robustness, prioritized access and others. We address physical layer related challenges, present an analytical model, hardware implementation and performance results from theoretical analysis, hardware measurements and simulations, which were run in comparison with the IEEE 802.11p. The results show high scalability and resilience to channel fading and variable topologies and a considerable performance improvement over IEEE 802.11p.