Key Technologies of High Speed Maglev Soft Handoff for MAC Layer

Abstract

As a high speed vehicle, maglev train requires a safe and reliable train-ground communication. Firstly, this paper analyses the high-speed maglev vehicle-to-ground communication system. In order to meet the requirements of low-delay, high-reliability maglev train transport management service transmission and ensure the probability of successful handoff, this paper designs a wireless network soft handoff mechanism based on MAC layer control of TDD system for handoff of high-speed maglev train. The relationship between the packet loss rate and the number of retransmissions is analyzed, and a reasonable frame structure is designed. The retransmit mechanism and signaling protection mechanism are adopted to improve the probability of successful soft handoff. Finally, through simulation, the improved algorithm’s probability of success achieves 99.6% and the handoff delay is 176 ms when the train speed is 600 km/h. Compared with the A3 algorithm, the probability of successful handoff is significantly improved, and the time delay of train handoff is guaranteed.