Access control schemes for high-speed train communications

With the fast deployment of high-speed railways of more than 300 km/h, providing quality of service of multimedia applications for users in the train is a key issue in wireless communications. The more challenging problem rests on the need to trade-off two performance metrics: the handover call dropping probability and the new call blocking probability. In this paper, we propose some prioritized access control schemes. These schemes take the advantages of the high-speed railway communication scenario. A position-based access factor is introduced to decrease the handover call dropping probability. In addition, separating resource reservation schemes are also proposed for both handovers and new calls. The system resource utilization has also been taken into account. Simulation results show that the proposed schemes may improve quality of service compared with schemes that do not apply the access factor and separating resource reservations.