Brief introduction of the CBTC System

It is characterized by the use of communication network to realize the two-way communication between train and ground equipment, and the use of real-time reported train position and calculation of mobile authorization to replace the fixed track section block to achieve train operation control.

CBTC outstanding advantages are that it can realize two-way communication between vehicle and ground, and can transmit large amount of information, fast transmission speed, easy to realize mobile automatic block system, greatly reduce interval laying cable, reduce one-time investment and reduce daily maintenance work. Flexible organization of two-way operation and one-way continuous departure, easy to adapt to different speed, different volume, different types of traction train operation control and so on. CBTC can not only realize train operation control, but also can be integrated into operation management, because two-way communication system can not only have two-way transmission of security information, but also two-way transmission of non-security information, such as vehicle number, crew group number, vehicle number, running time, locomotive status, fuel consumption parameters and a large number of locomotive, public works, electrical and other related information. Using CBTC can not only realize fixed automatic block system (CBTC-FAS), but also realize mobile automatic block system (CBTC-MAS). A key technology in CBTC application is two-way wireless communication system, train positioning technology, train integrity detection and so on. Among two-way wireless communication systems, it is applied in Europe, but GSM-R other kinds of wireless communication technologies such as spread spectrum communication are used in America. Train positioning technology has a variety of ways, such as vehicle equipment speed- ranging system, global satellite positioning, induction loop and so on.

Characteristics of the CBTC System

CBTC has many characteristics compared with traditional railway signal systems, such as:

• Instead of complicated cables, wireless communication systems are used to reduce cable laying and maintenance costs.
• It can realize the two-way communication between the vehicle and the control center, and greatly improve the capacity of train passage.
• The information transmission flow is large, the efficiency is high, the speed is fast, easy to realize the moving automatic block system.
• Easy to adapt to various models, different speed, different volume, different traction mode of trains, strong compatibility.
• Information can be classified and transmitted, centralized transmission and centralized processing to improve the efficiency of the dispatching center.

Application of the CBTC System

CBTC can use a variety of two-way communication systems, Europe, for example, uses GSM-R systems, The United States uses a variety of other wireless communication systems, such as spread spectrum communications, China uses wireless free wave, waveguide tube, leakage cable or three combination of ground vehicle information transmission mode. At present, the CBTC system is used by the New York subway in the United States, the Taipei MRT Lake Line in Taiwan, Chinese mainland some urban rail transit uses CBTC systems, Such as Wuhan Metro Line 1, Shanghai Rail Transit Line 8, Beijing Metro (except Line 13), Guangzhou Metro (except Line 1,2,8), Kunming subway, etc. Among them, The successful opening of Beijing Metro Yizhuang Line marks China's becoming the ground transportation department following Germany's Siemens, France's Alstom and France's Tirez, After Bombardier, Canada, the fifth country to successfully master CBTC core technology and successfully open practical engineering, To achieve the highest cost-effective life cycle goal, About 20% lower than the introduction system. Construction projects include: Guangzhou Line 6 and so on.

Function of the CBTC System

Communication traffic control can contain different levels of track automation technology, including the following main functions:

• Automatic train protection (ATP,Automatic Train Protection)
• Automatic train operation (ATO,Automatic Train Operation)
• Automatic train monitoring (ATS,Automatic Train Supervision)

Additionally, individual vendors also use data communication systems (DCS,Data Communication System) as subsystems independently.