A subway system consists of one or more lines, a control center, and one or more depots. Each line is about 10-20KM, usually 10-20 stations. Most of the communication takes place at the station/vehicle section and the control center.
Transmission Subsystem (OTN), Programmable Switch (PABX), Wireless (RADIO), Broadcast (PA), Television (CCTV), Network Management (NMS), and Uninterruptible Power Supply (UPS). The subway communication system consisting of these 8 subsystems not only provides various services such as voice, TV image and data for the city subway, but also provides control and data channels for the traffic control and environmental control systems of the subway line. Therefore, the subway communication system is a communication link network integrating voice, image, data and control channels, ensuring the provision of transmission services, providing information to passengers, and ensuring high-level control of stations and passengers on board, and ensuring Their safety.
FR-8000 Advantage Description
OTN is an open-loop fiber-optic loop transmission network. Its biggest feature is that it can configure transmission bandwidth through network management and according to user requirements. It has a rich user interface, can transmit broadband digital video and Ethernet information, and provides 1+1 loop self. The more protection function, the higher the network security. The OTN device has a transmission system to control the collinear digital compressed video channel and interface. The network interface has an internal interface connected to other OTN networks, and also has an external interface compatible with the SDH service, the FC service, and the CPRI service, thereby facilitating the connection. Other networks are easy to connect.
Since OTN has the above advantages, China has obtained corresponding applications in Guangzhou Metro, Shanghai Metro, Chongqing Metro, Nanjing Metro, etc. It can be said that OTN has certain advantages in the application of subway.
solution
The fiber loop of the transmission system adopts the dual-fiber bidirectional channel protection mode, and the transmission of the optical cable in the subway is assumed to form a loop network on both sides of the tunnel, as shown in Fig. 1. The nodes in the OTN network are interconnected by point-to-point fibers that form two loops that are in reverse loops.
A ring that transmits data clockwise in FIG. 1 is referred to as a primary link, and a ring that transmits data in a counterclockwise direction is referred to as a backup link. In normal operation, all data is transmitted in the clockwise direction on the primary link, while the standby link is in the backup state. The backup link works mainly to keep pace with the primary link and monitor the primary chain at all times. The working state of the road. In the event of a failure, he can quickly replace all the traffic in the transmission on the primary link, and automatically recover to the primary link after the failure is fixed.
In the actual subway project, the distribution of each station is often chain-like. In order to form a loop, we use a jump link to form a loop. as shown in picture 2
The FR8000 series is a transmission system developed for the application of the metro field. It takes into account all the application needs of the subway and integrates the interfaces and functions required for all services in the subway.
Modern communication transmission systems are not only used for traditional voice and data communication, but also widely used as a backbone transmission network for dedicated control networks formed by various industrial and traffic control systems. This requires the transport backbone network to be highly serviceable, highly reliable and highly available in order to ensure safe and reliable operation of the control network formed thereon. OTN's self-healing capability for system failure provides users with a reliable transmission network. Therefore, in the subway project, not only used as the transmission backbone of the communication system, but also provides transmission channels for each driving control system and environmental control system, such as signal system (point-to-point mode of RS422 card), station equipment control System (BAS, Ethernet), power monitoring system (SCADA, RS422 card point-to-point mode) and automatic ticket checking system (AFC, RS422 card point-to-point mode), etc. are all using OTN network as a transmission channel to form control The internet.
A subway system consists of one or more lines, a control center, and one or more depots. Each line is about 10-20KM, usually 10-20 stations. Most of the communication takes place at the station/vehicle section and the control center. Various types of voice communication (scheduling telephone, emergency telephone), broadcasting, wireless system, signal system, power monitoring system, ticketing system, and environmental control system constitute a communication and control network. With the OTN network, the transmission of this system can be unified in a single, integrated system. Due to the anti-harsh environment (EMC/EMI/EFI) capability of the fiber, the high serviceability of the OTN network, high reliability and high availability, and its flexible networking capabilities, the OTN network is particularly suitable for metro systems.
FR-6000+FR-8000 application diagram
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