The vehicle-ground safety communication of the New Train Control System adopts a brand-new underlying network and a communication mechanism of safe and reliable transmission. Based on the GPRS packet switching network, the data link layer adopts the PPP protocol, and the TCP protocol is adopted in the transmission layer to provide reliable transmission services. According to the GPRS network service quality index and the retransmission mechanism of the TCP protocol in the transport layer, this paper adopts the Matlab/SimEvents discrete event simulation method and uses the entity as the communication carrier to conduct a hierarchical and modular system-level modeling of New Train Control System vehicle-ground communication protocol. It simulates the communication process of the message from the application layer, the security layer to the transport layer, and finally transmitted on the GPRS network channel with random delay and packet loss probability. From the quantitative point of view, this paper analyzes the safety connection establishment time and success rate of the new train control system vehicle-ground wireless communication under different channel conditions, the timeliness of the non-periodic message receiving a reply to complete the specific scene function, and the reliability of the periodic message receiving delay. The analysis results show that the new train control system vehicle-ground wireless communication adopts GPRS network and TCP protocol retransmission mechanism to improve the real-time and reliability of communication.
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