关键词: 移动性增强, 铁路5G专网, 条件切换, 双激活协议栈, 快速切换失败恢复

Abstract: Ultra-Reliable and Low-latency Communication (URLLC) is one of the three major characteristics of 5G mobile communication systems, and mobility enhancement is a key technology to achieve ultra-high reliability and low-latency characteristics. The 5G for Railways (5G-R) network also has those requirements, to provide reliable connectivity and enhanced performance for safe and efficient railways. During the high-speed operation of trains, the user equipment (UE) needs to continuously handover between adjacent cells. This paper mainly discusses the application scenarios of three functions of the mobility enhancement technology, conditional handover, dual active protocol stack and fast handover failure recovery, in the 5G-R network. According to the working mechanism of these three functions and the characteristics of the 5G-R network coverage model, this paper believes that the dual active protocol stack and fast handover failure recovery have good application value in reducing service interruption delay and ensuring train operation safety.

Key words: mobility enhancement, 5G-R network, conditional handover, dual active protocol stack, fast handover failure recovery