Boasting fast speed, safety, punctuality, small land use, large carrying capacity, low energy consumption and small pollution, urban railway transportation has been the first choice for the public transportation in all major cities of the world.

In urban railway transportation, several trains run at high speeds on enclosed tracks and the time intervals between them are very short. Hence, an efficient and reliable dispatch system must be established to keep trains operating in a safe and efficient manner.

System Requirements

1. Fast call set-up and reliable call quality

The dispatch system is mainly used to help personnel interact with one another, control the train departure, stop and acceleration as well as coordinate proper operations of the whole railway transportation. In this regard, the major functions of the dispatch system include:

• Rolling stock depot (parking lot) dispatch
• Platform dispatch

In case of emergency, the dispatch system can be used to organize and coordinate actions taken by emergency response teams.

No matter in daily dispatches or emergencies, fast call set-up and reliable call quality are the most important requirements for the dispatch system.

2. Customizable dispatch console

The railway transportation dispatch center monitors the operation conditions of the whole railway transportation and uses dispatch consoles to control trains by issuing different commands. Urban railway transportations in different cites vary from one another, so it is required to customize dispatch consoles for each city according to their transportation characteristics. These consoles are all tailored for the purpose of satisfying functional requirements and facilitating operations to the utmost.

3. High-speed wireless data access

With the development of science and technology, a lot of control technologies are applied to control railway transportation dispatches. All train condition information (such as the internal temperature, noxious gas concentration, train axle temperature and realtime speed) and compartment video images must be transferred to the dispatch center to facilitate the control of train status. Therefore, the dispatch system must have a high-speed wireless data access.

4. High performance-price ratio

Presently, the majority of the railway transportation dispatch systems in use have paid exorbitantly high costs in system construction and maintenance, and terminal procurement as they were imported from other countries. The accelerating development of urban railway transportation in China cries out for high performance-price ratio dispatch communication systems.

Solution

To address the pressing needs, ZTE has customized its self-developed GoTa trunking technologies and launched a solution that can fully meet the dispatch requirements. This solution not only improves the economic and social benefits of railway transportation enterprises, but also saves huge financial and material resources for the state’s urbanization process.

The following figure shows the network topology of ZTE railway transportation dispatch communication system. The dispatch control center is connected with the GoTa system through IP network and by using the GoTa system, the control center implements the railway transportation dispatch.

Figure 1 ZTE railway transportation dispatch communication system

1. Dispatch control center

A dispatch control center consists of several dispatch consoles, Including:

• Traffic dispatch console: implements dispatch of trains on the go. The station can make calls to trains on the move and receive calls from them.
• Parking lot dispatch console: implements dispatch of the trains in parking lots. It can call the trains in parking lots (for example, inform the trains to prepare for running) or receive calls from incoming trains and offer helps and guidance to them.
• Security dispatch console: coordinates security personnel’s works.
• Maintenance dispatch console: coordinates maintenance personnel’s works.

Currently, the dispatch consoles adopt the popular WEB mode that enables them to upgrade on the GoTa server other than on each console computer. Moreover, the dispatch consoles provide open customization interfaces to allow for secondary development according to different transportation requirements. After customization, the dispatch consoles will provide the most suitable function options and the most convenient operation modes for the dispatch control center to use various dispatch and monitoring functions conveniently.

2. GoTa network

As a control node of trunking calls, GoTa controls the set-up and release of dispatch calls and provides services to the dispatch consoles in the dispatch control center.

Besides group, one-to-one and broadcasting calls, GoTa system also provides abundant high-level trunking services so as to ensure the dispatch commands can be delivered rapidly and accurately. For example:

• Priority: Dispatch consoles have the highest priority to ensure that the dispatch control center issue can commands at any time and all trains and stations receive the commands immediately.
• Function number: GoTa system transfers function number calls to appointed post terminals, simplifying the operation process.
• Emergency call: With the highest priority, emergency calls can be set up rapidly even under the condition of resource congestions, ensuring the emergencies can be handled in a timely manner.

In order to meet railway transportation enterprise requirements for diversified communication services such as general communications, remote monitoring and wireless official businesses, ZTE solution integrates general mobile voice call, multi-media and high-speed wireless data access (maximum 3.1 Mbit/s by EV-DO REV.A and 14.7Mbit/s by EV-DO REV.B) functions. For example, the solution transfers a large amount of video monitor and train condition information to the dispatch control center so that the dispatch and control center can control train conditions in a timely manner.

ZTE solution provides highly-efficient and economical network coverage over the dispatch and control center, rails, tunnels and stations in different ways.

• For short and straight tunnels, adopt external high-power transmitters (or repeaters for long distance coverage).

Figure 2 Short tunnel coverage solution

• For long and winding tunnels, adopt leakage cables or in-tunnel outdoor microcellular stations.

Figure 3 Long and winding tunnel coverage solution

GoTa provides feature-rich, reliable and secondary-development-capable interfaces to address the high reliability and complex interface needs of the purpose-built railway dispatch system.

Figure 4 Schematic diagram of GoTa second development

The Dispatch Agent System (DAS) is the access unit of the GoTa system dispatch consoles. DAS provides access services to the dispatch consoles and executes the control commands issued by the dispatch consoles, such as group call and one-to-one call commands.

Data of the ATS data server comes from the automatic ATS control system, including the information of train location, train number, train group and train mounted stations. In the secondary development of dispatch system, the dispatch consoles mainly obtain some dynamic data through the ATS data server, including the information on the relationship between train numbers and train IDs as well as train locations.

DWS indicates the PC used by dispatchers. The commands issued by DWS are executed by DAS.

3. Terminal

ZTE offers varieties of terminals including vehicle-mounted stations, handsets and modules. Moreover, ZTE packages the implementation of GoTa call dispatch into a hardware module for third-party vendors to customize and develop handheld terminals and train mounted stations.

Figure 5 Serialized terminals

Customer Benefits 

Compared with other railway dispatch system solutions, ZTE solution has striking advantages in terms of customization capability, function as well as system and terminal prices.

• Full customization capability

The dispatch console provides fully open interfaces by which transportation enterprises can customize 100% suitable dispatch consoles for themselves. ZTE packages the implementation of GoTa call dispatch into a hardware module. Customers only need to design terminal peripherals for interconnection with ZTE hardware module.

• Abundant services

ZTE solution provides a full set of wireless mobile services to the network, including dispatch calls, mobile voice and high-speed wireless data access. This not only satisfies customers’ requirements, but also saves costs for them.

• Low cost

Based on mature CDMA technology, ZTE provides professional end-to-end trunking solutions at a reasonable price to save capital investment for transportation companies.

• Professional after-sales service team

As one of the largest communication equipment vendors in China, ZTE boasts strong R&D and after-sales service capabilities. ZTE’s professional after-sales teams in all the provinces and cities of China offer 7*24 hour services to ensure safe and reliable GoTa system operation.