CN201226519Y - Communication system for railway special network based on passive optical network - Google Patents

Abstract

The utility model discloses a railway special network communication system based on a passive optical network. The utility model solves the problems that the existing railway special network communication system based on twisted pair has high maintenance cost and limited bandwidth, can not satisfy practical application, and the like, and has the advantages of simple structure, lower cost, enough bandwidth, satisfying practical application, and the like, and is an ideal proposal for railway special network upgrading and transformation. The railway special network communication system comprises at least three optical fibers; and one of the optical fibers is a main trunk line used for changing adjacent sites and connecting transmission devices; the other two of the optical fibers are provided with connection post monitoring points every other two km, and passive optical couplers are placed to realize the connection of a railway tour line phone and an emergency communication device. A mode with one wavelength broadcast is adopted in the directions of the site device to each connection post monitoring points; and a mode with WND is adopted in the directions of the connection post monitoring points to the site device, and a plurality of the connection post monitoring points are allowed to be communicated with the site device at the same time.

Description

Railway private network communication system based on passive optical network

technical field

The utility model belongs to the technical field of optical fiber communication, and is a special railway network communication system based on a passive optical network.

Background technique

With the rapid development of my country's economy, the railway transport capacity has increased year by year, which puts forward higher requirements for the informatization of the railway private network. At present, most of the old railway lines still use copper wire as the transmission medium, and the information transmission bandwidth and transmission distance are limited (the commonly used SHDSL symmetrical transmission system can only transmit information with a bandwidth of 2Mb/S on a copper wire with a diameter of 0.9mm. The transmission is about 13Km, and the transmission bandwidth is 4-5Mb/S, the distance is only a few kilometers), the signal transmission quality is unstable, and for the section with a large distance between stations, multiple active stations are required. Moreover, with the passage of time, the lines are seriously aging and the maintenance costs are high. It is imminent to implement optical cable transformation on these railway information communication lines.

At present, some railway lines use the GSMR system to form a railway private network communication. This method has high investment costs and limited bandwidth, and the bandwidth is limited when transmitting dynamic emergency images. There are some railway ends where optical fibers are laid, and optical cables are generally only used for information transmission between railway stations, and there are basically no applications for daily line inspection and emergency communication.

Utility model content

The purpose of this utility model is to solve the problems of high maintenance cost and limited bandwidth of the current railway private network communication system based on twisted pair, which cannot meet the practical application, and provide a simple structure, low cost, and sufficient bandwidth to meet The railway private network communication system based on passive optical network with practical application and other advantages.

In order to achieve the above object, the utility model adopts the following technical solutions:

A railway private network communication system based on passive optical network, its structure is as follows: it includes at least 3 optical fibers, one of which is the main line, which is used for the connection of switching and transmission equipment between adjacent stations, and the other two Set up terminal monitoring points at 2Km, place passive optical couplers, and realize the access of railway line inspection telephones and emergency communication equipment. In the direction from the site equipment to each terminal monitoring point, one wavelength broadcast is adopted; in the direction from the terminal monitoring point to the site equipment, the wavelength division multiplexing method is adopted, allowing several terminal monitoring points to communicate with the site equipment at the same time .

Described site equipment comprises wavelength division multiplexer, and it is connected with audio frequency, video data processing module by optical transceiver unit, and audio frequency, video data processing module grounds Ethernet data signal, video signal, audio signal; In wavelength division multiplexer There is an optical line sending module and several optical line receiving modules between the audio and video data processing modules.

The railway line inspection telephone is connected to the optical line through the passive optical coupler, and connected to the program-controlled telephone exchange through several FXO interfaces of the station equipment, thereby realizing the telephone line inspection.

The emergency communication equipment is connected to the optical line by a passive optical coupler, and after being processed by the adjacent site equipment, it is relayed and transmitted by the optical transmission equipment in the switching and transmission equipment of each site equipment to the emergency command center equipment, where Audio, video and data signals were recovered from the emergency command center equipment.

The emergency command center equipment includes an Ethernet switch, which is connected to the video server through the Ethernet, and is connected to the program-controlled switch through the soft switch device and the relay gateway; at the same time, the Ethernet switch also directly transmits Ethernet data.

The switching and transmission equipment includes layer 3 Ethernet switches, fiber optic transceivers or SDH transmission equipment.

The railway private network communication system based on the passive optical network of the utility model adopts a passive optical coupler at the terminal monitoring point, and adopts a wavelength broadcasting method in the direction from the station to each terminal monitoring point; The direction from the monitoring point to the site can adopt the method of wavelength division multiplexing, allowing several terminal monitoring points to communicate with the site equipment at the same time. The 40Km section does not need an active relay, and the 80Km section only needs one active relay station. It is used in railway line inspection telephone applications and emergency communication applications.

The utility model adopts passive optical network and wavelength division multiplexing technology, and a passive optical coupler is placed at each terminal monitoring point. The distance between the two terminal monitoring points is 2Km, so there are 19 There are 39 optocouplers on the 80Km section. During communication, one wavelength broadcasting method is adopted in the direction from the site to each terminal monitoring point; while in the direction from the terminal monitoring point to the site, the wavelength division multiplexing method can be used, allowing several terminal monitoring points to communicate with the site at the same time Device communication.

For the 40Km section, there are 19 couplers. If a coupler with a splitting ratio of 90/10 is used, the total insertion loss from the last optical coupler to the 19 optical couplers in the inter-station equipment is 19×0.62=11.78dB , the insertion loss of the device connected by an arm with a splitting ratio of 10 is: 12dB, and the loss of a 40Km optical fiber is 40×0.3=12dB. The total loss is: 11.78+12+12=35.78dB. If both the site equipment and the terminal monitoring point equipment use DFB optical modules, the transmission power can reach +2dBm, and the receiving sensitivity of the optical receiving (PIN/FET) module can reach -38dBm when the transmission rate is 125Mb/S. It can be seen that there is no need to use active relay stations on the 40Km section. For the section greater than 40Km, an active relay station is required. Since the section distance will not be greater than 80Km, only one active relay station is required at most.

The utility model has the beneficial effects that the system is simple in structure, low in cost, and can provide sufficient bandwidth to meet the actual needs of upgrading and reforming the current railway special network. The 40Km section does not need an active relay station, and the 80Km section only needs one active relay station, which is convenient for implementation.

Description of drawings

Fig. 1 is a system block diagram of the utility model;

Figure 2 is a block diagram of the site equipment;

Fig. 3 is the principle block diagram of line patrol phone application;

Fig. 4 is a functional block diagram of emergency communication application;

Figure 5 is a block diagram of the equipment structure of the emergency communication command center.

Among them, 1. Switching and transmission equipment, 2. Site equipment, 3. Passive optical coupler, 4. Wavelength division multiplexer, 5. Audio and video data processing module, 6. Optical line receiving module, 7. Optical line Sending module, 8. Line patrol telephone, 9. Program-controlled telephone exchange, 10. Emergency communication equipment, 11. Emergency command center equipment, 12. Ethernet switch, 13. Soft switch equipment, 14. Relay gateway, 15. Video server .

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described further.

The system architecture and functional block diagram are shown in Figure 1. It includes a number of switching and transmission equipment 1 set on the trunk line, each switching and transmission equipment 1 corresponds to a site equipment 2, communicates between adjacent site equipment 2 through an optical fiber, and sets a number of switches on the other two optical fibers A terminal monitoring point, the terminal detection point adopts passive optical coupler 3, adopts at least one wavelength broadcasting method in the direction from site equipment 2 to each terminal monitoring point; The direction adopts the method of wavelength division multiplexing, allowing several terminal monitoring points to communicate with the station equipment 2 at the same time; at the same time, the terminal monitoring points are also connected to the railway line inspection telephone 8 and emergency communication equipment 10 .

If both site equipment 2 and terminal monitoring point equipment use DFB optical modules, there is no need to use an active relay station on the 40Km section, and only one active relay station is required on the 80Km section.

Among Fig. 2, site equipment 2 comprises wavelength division multiplexer 4, and it is connected with audio frequency, video data processing module 5 through optical transceiver unit, and audio frequency, video data processing module 5 grounds Ethernet data signal, video signal, audio signal; There is an optical line sending module 7 and several optical line receiving modules 6 between the wavelength division multiplexer 4 and the audio and video data processing module 5 .

The optical signals of different wavelengths from the monitoring points of each terminal post reach the corresponding optical receiving unit after passing through the wavelength division multiplexer, and then reach the audio, video and data processing unit after passing through each optical receiving unit, and recover the audio, video and data signals . One wavelength (1310nm) broadcasting method is adopted in the direction from the station to each terminal monitoring point. Audio, video and 10/100M Ethernet data signals are sent to the optical transmission unit after processing, and then enter the optical line to be sent through the wavelength division multiplexer. To each terminal monitoring point.

In Fig. 3, the railway line inspection telephone 8 is connected to the optical line through the passive optical coupler 3, and connected to the program-controlled telephone exchange 9 of the switching and transmission equipment 1 through several FXO interfaces of the station equipment 2, thereby realizing telephone line inspection.

In Figure 4, the emergency communication equipment 10 is connected to the optical line by the passive optical coupler 3, after being processed by the adjacent site equipment 2, it is relayed and transmitted by the optical transmission equipment in the switching and transmission equipment 1 of each site equipment 2 After arriving at the emergency command center equipment 11, the audio, video and data signals are recovered in the emergency command center equipment 11.

Among Fig. 5, emergency command center equipment 11 comprises Ethernet switchboard 12, and it is connected with video server 15 through Ethernet, connects program-controlled switchboard through soft switch equipment 13, relay gateway 14 simultaneously; Ethernet switchboard 12 also directly transmits Ethernet data.

Switching and transmission equipment 1 includes layer 3 Ethernet switches, fiber optic transceivers or SDH transmission equipment.

Claims (6)

1. railway private network communication system based on EPON, it is characterized in that, it comprises at least 3 optical fiber, article 1, be basic routing line, be used between the adjacent sites connection of exchange and transmission equipment, other 2 are provided with the binding post monitoring point every 2Km, place passive optical coupler, realize the access of railway patrol telephone and emergency communication equipment; Adopt the mode of 1 wavelength broadcasting to the direction of each binding post monitoring point at site apparatus; And adopt the mode of wavelength division multiplexing to the direction of site apparatus in the binding post monitoring point, allow several binding posts monitoring point to communicate by letter with site apparatus simultaneously.

2. the railway private network communication system based on EPON as claimed in claim 1, it is characterized in that, described site apparatus comprises wavelength division multiplexer, it is connected with audio frequency, video data processing module by the light Transmit-Receive Unit, and audio frequency, video data processing module are landed Ethernet data signal, vision signal, audio signal; Between wavelength division multiplexer and audio frequency, video data processing module, an optical link sending module and several optical link receiver modules are arranged.

3. the railway private network communication system based on EPON as claimed in claim 1, it is characterized in that, described railway patrol telephone equipment is through passive optical coupler incoming light ray road, is connected to SPC telephone exchange through several FXO interfaces of site apparatus, thereby realizes the phone line walking.

4. the railway private network communication system based on EPON as claimed in claim 1, it is characterized in that, described emergency communication equipment is by passive optical coupler incoming light ray road, after adjacent site apparatus is handled, by arriving Police Command Center equipment after the exchange of each site apparatus and the optical transmission device relay transmission in the transmission equipment, in Police Command Center equipment, recover audio frequency, video and data-signal.

5. the railway private network communication system based on EPON as claimed in claim 4, it is characterized in that, described Police Command Center equipment comprises Ethernet switch, and it is connected with video server by Ethernet, is connected to stored-program control exchange through Softswitch, Tandem Gateway simultaneously; Ethernet switch also directly transmits Ethernet data simultaneously.

6. the railway private network communication system based on EPON described in claim 1 or 3 or 4 or 5 is characterized in that described exchange and transmission equipment comprise 3 layers of Ethernet switch, fiber optical transceiver or SDH transmission equipment.

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