中文摘要：

根据GSM-R和LTE-R的越区切换过程，考虑信道占用、信道质量、参数设置、单点故障和多普勒频移5个主要因素对越区切换的影响，利用随机Petri网分别建立GSM-R和LTE-R的越区切换模型，比较研究不同列车运行速度时二者的越区切换成功率，以及频谱、列车运行速度对LTE-R越区切换成功率的影响。结果表明：越区切换成功率均随列车运行速度的增加而降低，但LTE-R的越区切换成功率高于GSM-R，且受列车运行速度增加的影响较小；LTE-R采用低频段800MHz的越区切换成功率高于高频段2．6GHz时。对于高频段的2．6GHz，列车运行速度低于350km·h^-1时，能够满足CTCS-3对数据传输安全性和可靠性的要求。

英文摘要：

According to the analysis of the handover processes of GSM-R （Global System for Mobile com- munications-Railway） and LTE-R （Long Term Evolution-Railway）, considering the influences on han- dover process by 5 major factors, namely, channel occupancy, channel quality, parameter setting, single point failure and Doppler shift, stochastic Petri nets were used to establish the handover models of GSM-R and LTE-R respectively. Both success rates were studied and compared under different speed, and the in- fluences of frequency spectrums and train running speed on the success rates of LTE-R were also studied. The results show that the handover success rate decreases with the increase of train speed, but the han- dover success rate of LTE-R is higher than that o{ GSM-R, and is less influenced by the increase of train running speed. LTE-R handover success rate of using 800 MHz low frequency is higher than that of using 2.6 GHz high frequency. For the 2.6 GHz high frequency, when train speed is under 350 km · h-1, the handover success rate can meet the requirement for the safety and reliability of data transmission in CTCS-3.