A Cross-Layer Admission Control Scheme for High-Speed Railway Communication System

In high-speed railway communication system, due to its intrinsic features, on-going services are more prone to drop than in common communication systems. Therefore, existing admission control (AC) schemes designed for common communication systems cannot be directly used, otherwise the service dropping probability (SDP) requirement cannot be guaranteed. In this paper, a cross-layer AC scheme is designed to improve system SDP performance in high-speed railway communication system. Firstly, we clearly classify the main potential origins of service dropping into two types: modulation and coding scheme (MCS) changed service dropping and handoff service dropping. And then corresponding adaptive resource reservation algorithms are proposed to improve SDP performance, where the influence of MCS change and the unique characteristics of high-speed railway communication are taken into account. Simulation results show that compared with traditional cutoff AC scheme, the proposed AC scheme can effectively improve SDP performance while maintaining fairly desirable performance of service blocking probability and system bandwidth utilization.