5G无线通信技术在城市轨道交通中的应用探讨

第五代移动通信(5G)网络将于2020年实现大规模商用，这意味着我国乃至全球无线通信将进入5G时代。无线通信系统是城市轨道交通通信系统的重要组成部分，是保障各系统信息无线传输和线路正常运营的重要前提。当前城市轨道交通无线通信系统存在系统传输速率较低、延时较长等局限性，随着传输信息量的急剧增长，已无法很好地满足各系统在高速移动环境下的无线信息传输需求。5G无线通信技术凭借其先天性技术优势，能提供更高的传输速率(10 Gb/s)、更低的传输时延(毫秒级)，以及高速移动(500 km/h)环境下更好的系统传输性能。对5G的典型应用场景、关键技术、典型网络架构进行研究，并结合城市轨道交通无线通信系统的特点，就5G在城市轨道交通领域从业务承载、网络架构、频段资源、信号覆盖、应用开发等方面的应用进行探讨。随着系统制式、标准化进程的逐步完善，各厂商产品链的日益丰富和成熟，5G无线通信技术必将在城市轨道交通中大有作为。

Application of the Fifth-generation (5G) Wireless Communications Technology in Urban Rail Transit

The fifth-generation (5G) mobile communications network is being planned to achieve large-scale commercial application in 2020, which means that China and wireless communications networks globally will enter an era of 5G. Wireless communications system forms a crucial part of an urban rail transit communications system, and it is an important prerequisite to ensure wireless transmission of information and the normal operation of railway lines. At present, the wireless communications system of urban rail transit has some limitations, such as low transmission rate and large delay. With the rapid growth of transmitted information, the current wireless communication system is becoming unable to meet the requirements of various systems under the high-speed mobile environment. 5G wireless communications technology, with its inherent technical advantages, can provide higher transmission rate (10 Gb/s), lower transmission delay (Millisecond class), and superior system transmission performance under high-speed mobile environments (500 km/h). In this paper, a typical network architecture, application scenarios and key technologies of 5G are investigated, and combined with the characteristics of the urban rail transit wireless communications system. Additionally, the application of 5G in the field of urban rail transit is discussed from the perspectives of application hosting services, network architecture, frequency resources, signal coverage, application development, etc. Owing to the gradual improvement of the system standardization processes and the increasingly mature product chains of various manufacturers, 5G wireless communications technology will certainly play a significant role in urban rail transit.