随着 LTE(long term evolution，长期演进)综合承载在城市轨道交通中应用的逐步深入，越来越多的车地通信业务承载在LTE 网络上。针对 LTE-M 综合承载 CBTC+集群(+其他宽带接入业务)的地铁业务组合，充分利LTE-M 承载信号的 AB 双网，通过 LTE RAN 共享技术，将传统单网承载的集群业务的应用模式改进成基于空中接口的、AB 双网主备保障的机制模式。正常情况下 A 网承载集群语音业务，当 A 网空口异常时终端重选至 B 网驻留或接入，显著提升了 LTE-M 综合承载业务中集群列调的可靠性。

With the wide application of long-term evolution (LTE) integrated bearer for urban rail transit, increasing number of vehicle-ground communication services are carried on the LTE network. This study analyzes the LTE-M (long term evolution-metro) integrated bearer service of CBTC + Trunk (+ other broadband access services) and fully utilizes the LTE-M A+B dual-net. The LTE RAN-Sharing technology improves the Trunk service mode of the traditional single-net bearer to a mode based on the air interface AB dual-net guarantee, which significantly increases the reliability of the Trunk service in the LTE-M integrated bearer service. In general, net-A carries the Trunk service, and the UE will reselect to net-B when net-A is in the signal-abnormal condition.

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