Railway wireless communication system supports data transmission and voice communication functions, such as train dispatching and mobile communication between railway sections, and it plays an increasingly important role in ensuring railway transportation safety. Designed mainly for voice communication, the existing single-channel analog wireless communication system is lagging behind technological development and growing transportation. The devices have long been plagued by a series problems including co-frequency interference in hub areas, difficult channel access, and poor voice quality.
(1) Serious interference
The existing system is prone to interference from radios operating at the same frequency inside or more often outside the system.
(2) Lack of central dispatching among sections
Repeaters that operate at different frequencies are deployed in different sections. Therefore, they cannot support trans-section calls. As a result, departments are unlikely to supervise various engineering tasks in an efficient way. Moreover, they lack real-time information of progress status and cannot respond rapidly to emergencies.
(4) Lack of communication between departments
As the departments work independently and communicate at different frequencies, they are isolated from each other, which further complicates central information management.
(5) Poor management of terminals
Terminals are used randomly, and specific responsibility is assigned to the users. In response to railway communication over a long distance, a simple, powerful, and cost-efficient wireless communication system must be put in place to support group calls and central dispatching, thus improving the operational efficiency of railways.
To answer all the challenges, Hytera designs TS-2601 wired link simulcast solution.
1. Build the system with each railway section as a unit; determine the number of base stations required for each unit through field electrical measurement(usually one base station every 15-20 kilometers);
2. Set up dual channels at railway crossings to support dial calling over DTME-based two-way radios;
3. Utilize existing equipment rooms, towers and links along railways for each base station; Connect base stations to the dispatching room with E1 lines of G.703 standard;
4. Connect the base station to the power supply system in the equipment room;
5. Deploy an integrated dispatching platform for voice transmission at the command center of the railway bureau to support trans-section calls within the simulcast system;
6. Equip each base station with Digital Cross Connect (DXC) to connect timeslots in series on one shared E1 link;
7. Deploy remote IP dispatching consoles in divisions like communication and signal, maintenance and power supply to facilitate dispatching respectively at railway sections.
With the simulcast transmission technology, this solution delivers large-scale seamless coverage along railways. Through conventional terminal signaling, the solution can manage mobile terminals and support digital call recording and inquiry. Combined with central dispatching capabilities, the system enables the railway bureau to flexibly and suitably assign tasks to various divisions, thus increasing productivity and responsiveness. In emergencies, a division center can dispatch and allocate human and material resources on the shortest notice.
1.Clear voice and no interference in overlapped areas
Benefiting from GPS phase synchronization and software definition radio and other cutting-edge technologies, the system effectively eliminates interference within overlapped coverage areas and delivers voice quality comparable to stereo radios within any coverage area.
2.Wire base station grouping
Base stations on any link can be grouped into any combinations, and the base station groups can work independently.
The central dispatcher can manage, monitor, troubleshoot, repair, maintain and dispatch link simulcast base stations and other equipment on a routine basis without the hassle of climbing up mountain-top iron towers.
4.Connectivity to recording server, consoles and network administrators
The integrated dispatching platform provides connectivity to one communication server, one recording server, multiple IP consoles and network administrators. Different access rights are assigned to users as needed.
Sustainable and scalable, one central link station can be connected to 26 wired simulcast base stations.
TS-2601 simulcast system
TC-780 and TC-880GM
Hanxi-Danjiangkou and Xiangfan-Chonqing railways under the Wuhan Railway Bureau, China
Chengdu-Suining-Chongqing railway, China