A Dual-Link Soft Handover Scheme for C/U Plane Split Network in High-Speed Railway
A Dual-Link Soft Handover Scheme for C/U Plane Split Network in High-Speed Railway
复制标题
高速铁路C/U平面分离网络双链路软切换方案
DOI：
10.1109/access.2018.2794770
复制
发表时间：
2018
期刊：
影响因子：
3.9
通讯作者：
Fan Lisheng
中科院分区：
文献类型：
--
作者：
Zhao Junhui;Liu Yunyi;Gong Yi;Wang Chuanyun;Fan Lisheng
基于C/U （control/user）平面分割的异构网络架构是5G通信系统的研究热点。这种新的高速铁路通信系统架构能够为乘客提供高质量的服务，如更高的系统传输容量、更好的传输可靠性和更低的同信道干扰。将较为关键的C平面扩展维护在可靠的低频段，保证传输的可靠性；将U平面扩展维护在可用的高频频段，满足日益增长的系统容量需求。但是，在C/U平面分离网中，为了保证传输的可靠性，还有很多问题需要解决。在高铁通信系统中，C平面由宏进化节点（enb）支持，U平面由小进化节点（enb）支持。不同宏观enb之间的切换涉及两种类型的切换，这直接降低了其在高铁中的适用性和可靠性。为此，本文提出了一种高铁C/U平面分网的双链路软切换方案。通过在列车上部署一个列车中继站（TRS）和两个天线，可以降低切换中断的概率。采用双播方式减少通信中断时间，并对宏内eNB切换和宏间eNB切换的信令流进行了详细设计。仿真结果表明，在宏观间eNB切换中，所提出的切换方案能够显著降低中断概率，提高切换成功概率。
The heterogeneous network architecture based on control/user (C/U) plane split is a research hot spot in the fifth generation (5G) communication system. This new architecture for the high-speed railway (HSR) communication system can provide high quality of service (QoS) for the passengers, such as higher system transmission capacity, better transmission reliability, and lower co-channel interference. The relatively critical C plane is expanded and maintained in a reliable low-frequency band to guarantee transmission reliability, and the U plane is supported by the available high-frequency band to meet the increasing system capacity demands. However, there are still many problems to be solved in the C/U plane split network to ensure reliable transmission. In the HSR communication system, the C plane and the U plane are supported by the macro evolved NodeBs (eNBs) and the small eNBs, respectively. The handover between the different macro eNBs involves two types of handovers, which directly reduces its applicability and reliability in HSR. Therefore, a dual-link soft handover scheme for C/U plane split network in HSR is proposed in this paper. By deploying a train relay station (TRS) and two antennas in the train, the handover outage probability will be reduced. Moreover, the bi-casting is adopted to decrease the communication interruption time and the signaling flows of the intra-macro eNB handover and inter-macro eNB handover are designed in detail. Simulation results show that the proposed handover scheme can significantly reduce the outage probability and improve the handover success probability in the inter-macro eNB handover.