QoS Enhancements using IEEE 802.11p WLANs for Communication Based Train Control Systems

Abstract: In near future, communication based train control (CBTC) systems will play a major role in the urban railway networks in the world. CBTC systems are an automated railway signaling system that makes use of telecommunications to ensure safe operation between rail vehicles. For the urban railways Wireless local area networks (WLAN) based CBTC is the best approach because of wide availability of WLAN equipments. In the earlier works, IEEE 802.11a based WLANs are used to provide bidirectional train ground communications. But these WLANs are not suitable for high speed environments with frequent change in network topology, which may result in communication interrupt and long latency. In this paper IEEE802.11p WLANs are used to provide better communication availability in the CBTC environment. In the proposed work Quality of service (QoS) parameter metrics like throughput, delay are analyzed by using NS-2. Simulated results show 802.11p is more suitable than 802.11a for CBTC systems.

Keywords: CBTC system, Quality of services, IEEE 802.11p, Vehicular Networks.