Abstract: The problem of multiple handover failures occurred several times during the testing and commissioning of Chizhou-Huangshan High-speed Railway are gradually investigated, and it is found that the fault occurred when the service cell initiated handover to the target cell (the cell with BSIC=50). This paper checks the CTCS-3 interface monitoring data of the trains with handover failure and signaling tracking data of the base station, and deeply analyzes the cell handover principle of the GSM-R system, to judge that the fault is determined to be a compatibility problem between the Triorail terminal and the base station, resulting in an abnormal BSIC decoding (in BSIC X0 configuration) and a handover failure. In view of this situation, after temporary measures are taken to either replace the Triorail terminal with the Funkwerk terminal or change the BSIC code, the test results show that the handover failure has not happened. However, it is still necessary to conduct in-depth cause analysis and disposal of abnormal BSIC decoding to avoid the recurrence of handover failure.

Key words: GSM-R, CTCS-3, Triorail terminal, network optimization, abnormal BSIC decoding, handover failure

摘要： 对池黄高铁联调联试期间多次发生切换失败的问题进行逐步排查，发现故障发生于服务小区向目标小区（BSIC=50的小区）发起切换时，查看切换失败车次C3接口监测数据与基站信令跟踪数据，并结合GSM-R系统小区切换原理深入分析，判断故障是车载特优洛终端与基站存在兼容性问题，导致BSIC解码异常（BSIC X0配置下）引起切换失败。针对该情况，采用临时措施将特优洛终端更换为Funkwerk终端或更换BSIC码后，测试结果显示切换失败的情况未再复现。但仍需对BSIC解码异常进行深层次的原因分析及处置，以避免切换失败的再次发生。

关键词: GSM-R, CTCS-3, 特优洛终端, 网络优化, BSIC解码异常, 切换失败