列控数据传输与GSM-R越区切换发生碰撞的建模与分析

Modeling and Analyzing of Data Transmission Colliding with GSM-R Handover in Train Control System

在CTCS-3级列控系统中,RBC与车载ATP通过GSM-R系统传输数据,保证列车运行安全。列车在线路上高速运行时,频繁发生越区切换。如果数据传输和GSM-R越区切换发生碰撞,将导致数据丢失重传,影响行车效率甚至行车安全。本文建立了数据传输与越区切换发生碰撞模型,利用该模型可以评估影响碰撞概率的因素,可以验证本文给出的计算碰撞概率公式,还可研究碰撞时间的分布情况。首先,通过模型仿真,发现数据长度、列车运行速度、数据发送周期均会影响碰撞的发生概率。数据长度越长,列车运行速度越高,数据发送周期越短,则数据传输与越区切换发生碰撞的概率越高。其次,利用'数据传输与越区切换发生碰撞模型'仿真出的碰撞概率与本文给出的碰撞概率计算公式计算出的理论值基本相同,证明了模型和公式的准确性。最后,利用碰撞模型仿真,研究碰撞时间的分布情况,并得到一些定性结论。

In the CTCS-3 train control system, RBC and ATP transmit data to each other through the GSM-R system to ensure train running safety. When a train runs on railway lines at high speed, the GSM-R handover will happen frequently. If the data transmission collides with the GSM-R handover, communication will be interrupted shortly and part of data will be lost and retransmitted. In this paper the model of data transmission colliding with the GSM-R handover was designed. The model can be used to assess the effects of collision probability factors, verify the collision probability formula and research the collision time distribution. The model simulation results show as follows： The longer the application layer data length, the higher the train speed; the shorter the data transmission period, the higher the collision probability between data transmission and GSM-R handover; the collision probability abtained from model simulation is basically consistent with the collision probability calculated with the proposed formula. So the correctness of the model and formula are proved. Finally, the collision time distribution is researched with the collision model, and some qualitative conclusions are drawn.