CN110290042B

CN110290042B - Transmission network system for rail transit

Info

Publication number: CN110290042B
Application number: CN201810225409.1A
Authority: CN
Inventors: 张桂园
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2018-03-19
Filing date: 2018-03-19
Publication date: 2020-11-06
Anticipated expiration: 2038-03-19
Also published as: CN110290042A

Abstract

The invention provides a transmission network system for rail transit, which comprises: the backbone ring network layer comprises a core switch arranged in a core node and a link connected with the core switch; the core nodes adjacent to each other are connected with the core switch by the link by using a network protocol IP networking technology to form a backbone ring network layer for rail transit; wherein the core node at the starting position is adjacent to the core node at the ending position. By the system, an integrated service transmission system of communication and signal transmission is realized by using IP networking, and compared with the technology of communication and signal independent networking, the system has the advantages that the required equipment is less, the implementation cost can be effectively reduced, and the development direction of rail transit integration is met; by adopting the switch, three-layer networking is realized, the networking is flexible, and the expandability is good.

Description

Transmission network system for rail transit

Technical Field

The invention relates to the technical field of rail transit, in particular to a transmission network system for rail transit.

Background

At present, a transmission system of information in urban rail transit is composed of a communication Network and a signal Network, and the existing transmission system includes a Multi-Service Transfer Platform (MSTP) based on SDH, a Resilient Packet Ring (RPR), and an Open Transfer Network (OTN).

Most of existing transmission systems are networked independently, communication services and signal services are transmitted separately, functions of three-layer networking (a physical layer, a link layer and a network layer) are not supported, an additional router needs to be added to achieve three-layer networking, and complexity and implementation cost of the network are increased. In addition, the transmission equipment is limited by the cross capability, the expandable space is limited, and the bandwidth requirement of the rapidly developed urban rail transit service is difficult to meet.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

Therefore, the invention provides a transmission network system for rail transit, which utilizes IP networking to realize a service comprehensive transmission system integrating communication and signal transmission, compared with the technology of independent communication and signal networking, the invention has the advantages of less required equipment, effectively reduced implementation cost and accordance with the development direction of rail transit integration; by adopting the switch, three-layer networking is realized, the networking is flexible, and the expandability is good.

The embodiment of the invention provides a transmission network system for rail transit, which comprises:

the backbone ring network layer comprises a core switch arranged in a core node and a link connected with the core switch;

the adjacent core switches are connected by the link by utilizing the IP networking technology to form a backbone ring network layer; wherein the core node at the starting position is adjacent to the core node at the ending position.

In the transmission network system for rail transit of the embodiment of the invention, the core switches are arranged in the core nodes, the adjacent core switches are connected by a link by using a network protocol IP networking technology to form a backbone ring network layer, and the backbone ring network layer is used for forming a transmission network system to transmit communication services and signal services. The integrated service transmission system integrating communication and signal transmission is realized by using IP networking, compared with the technology of independent communication and signal networking, the system has the advantages that the required equipment is less, the implementation cost can be effectively reduced, and the development direction of rail transit integration is met; by adopting the switch, three-layer networking is realized, the networking is flexible, the expandability is good, and the technical problems that the three-layer networking cannot be realized and the expandability is poor in the prior art are solved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of a first transmission network system for rail transit according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a second transmission network system for rail transit according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a third transmission network system for rail transit according to an embodiment of the present invention;

FIG. 4 is a schematic view of an access topology of a communication and signal service subsystem access network;

FIG. 5 is a schematic diagram of a ring network protection method; and

fig. 6 is a schematic diagram of a network topology of a transmission network system according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

A transmission network system for rail transit according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

To facilitate understanding of the embodiments of the present invention, the following explains terms that may be involved in the embodiments of the present invention:

communication service: the service System includes Public telephone service, private telephone service, Office Automation (OA) service, Passenger Information System (PIS) service, Closed Circuit Television (CCTV) service, environment and equipment monitoring System (Electrical and Mechanical control System-EMCS or Building Automatic System-BAS) service, broadcast System (PA) service, Automatic Fare Collection System (Automatic Fare Collection System, FAS) service, and Fire Alarm System (Fire Alarm System, FAS) service.

Signal service: the System comprises Automatic Train monitoring System (ATS) service, Automatic Train Protection System (ATP) service, and Maintenance Support System (MSS) service.

The existing transmission system applied to urban rail transit separately performs networking transmission on communication services and signal services, for example, different services are managed by using MSTP equipment and IP equipment respectively, so that professional personnel of different services are required to maintain the equipment, and the maintenance cost is increased.

At present, because the transmission of signal service is carried out by using a switch for networking, and each communication subsystem is basically IP-based for transmitting communication service, and a general core switch is used as transmission network equipment without any technical obstacle, the comprehensive networking transmission of the communication service and the signal service by using an IP networking mode is feasible and effective. Based on this, the embodiment of the invention provides a transmission network system for rail transit, which can comprehensively bear communication services and signal services, realize integration of communication and signal transmission, facilitate unified management and reduce maintenance cost.

Fig. 1 is a schematic structural diagram of a first transmission network system for rail transit according to an embodiment of the present invention.

As shown in fig. 1, the transmission network system 10 for rail transit includes: a backbone hoop layer 110.

The backbone ring layer 110 includes core switches 111 provided in the core nodes and links 112 connecting the core switches. Wherein the core nodes include, but are not limited to, a control center node, and at least one centralized station node and/or at least one vehicle segment node, the core nodes not shown in fig. 1.

In this embodiment, when constructing the backbone ring network, the adjacent core switches 111 are connected by using the IP networking technology through the link 112 to form the backbone ring network layer 110. The core node at the starting position is adjacent to the core node at the end position, that is, the core switch at the starting position is adjacent to the core switch at the end position.

It should be noted that the IP networking technology is prior art, and the present invention is not described in detail to avoid redundancy.

In the transmission network system for rail transit of the embodiment, the core switches are arranged in the core nodes, the adjacent core switches are connected by links by using a network protocol IP networking technology to form a backbone ring network layer, and the backbone ring network layer is used to form a transmission network system for transmitting communication services and signal services. The integrated service transmission system integrating communication and signal transmission is realized by using IP networking, compared with the technology of independent communication and signal networking, the system has the advantages that the required equipment is less, the implementation cost can be effectively reduced, and the development direction of rail transit integration is met; by adopting the switch, three-layer networking is realized, the networking is flexible, the expandability is good, and the technical problems that the three-layer networking cannot be realized and the expandability is poor in the prior art are solved.

In the prior art, one device is deployed at each station to complete data transmission, and when the device at one station fails, the access of the whole station is interrupted, so that the reliability is poor.

In order to solve the problem, the embodiment of the invention provides another transmission network system for rail transit, so as to improve the reliability of the network.

Fig. 2 is a schematic structural diagram of a second transmission network system for rail transit according to an embodiment of the present invention.

As shown in fig. 2, based on the embodiment shown in fig. 1, in the transport network system 10 for rail transit, each core node includes two core switches, namely a first core switch and a second core switch, and the first core switch and the second core switch in each core node are respectively marked as 111-a and 111-B. Links 112 in system 10 include a first link 112-a and a second link 112-B. Wherein adjacent first core switches 111-a are connected by a first link 112-a to form a first loop; and adjacent second core switches 111-B are connected by second links 112-B to form a second loop, the first loop and the second loop forming a backbone ring network layer.

In this embodiment, the established backbone ring network layer is utilized to perform transmission of communication service and signal service in rail transit. When one of the first loop and the second loop fails, data transmission is continued through the other loop. For example, when the first loop fails, the second loop is switched to continue to transmit data.

As shown in fig. 2, adjacent first core switches 111-a are connected by a first link 112-a to form a first loop, and adjacent second core switches 111-B are connected by a second link 112-B to form a second loop, the first loop and the second loop forming a backbone ring layer 110.

It should be noted that fig. 2 only illustrates the embodiment of the present invention by taking the first core switch 111-a in each core node connected through the first link 112-a and the second core switch 111-B in each core node connected through the second link 112-B as an example, and should not be taken as a limitation to the present invention. The first link 112-a may also connect to a second core switch 111-B in the core node, and the second link 112-B may also connect to a first core switch 111-a in the core node, as long as it is satisfied that the first link 112-a and the second link 112-B connect to two different core switches in one core node, respectively.

In this embodiment, the first core switch 111-a and the second core switch 111-B in each core node may be virtualized into one core switch by a virtualization technology, for example, a stacking technology may be adopted, and the first core switch 111-a and the second core switch 111-B may be logically changed into one core switch by using a cable connection interface connecting the core switch 111-a and the core switch 111-B. Therefore, when one core switch fails, the other core switch can continue to work normally, and the reliability of the core node can be improved.

In the transmission network system for rail transit of this embodiment, a first core switch and a second core switch are deployed at each core node, and a first link and a second link are set, adjacent first core switches are connected by the first link to form a first loop, adjacent second core switches are connected by the second link to form a second loop, and the first loop and the second loop form a backbone loop network layer, so that redundant backup of the core switches and the network links can be realized, the reliability of the core switches and the network is improved, and the technical problem of poor reliability in the prior art is solved.

Furthermore, for non-centralized stations, such as stations, only communication services can be formed by laying a convergence switch and using the centralized station as a tangent point to form a ring network. Thus, in a possible implementation manner of the embodiment of the present invention, as shown in fig. 3, on the basis of the embodiment shown in fig. 2, the transmission network system 10 for rail transit may further include: at least one aggregation ring layer 120 of the backbone ring layer 110 is accessed at a core node.

Specifically, the convergence mesh layer 120 includes: an aggregation switch 121 disposed in a non-core node (i.e., a non-centralized station, not shown in fig. 3) and a third link 122 connecting the aggregation switch. Adjacent aggregation switches 121 are connected by a third link 122 using an IP networking technology to form an aggregation ring layer 120.

Further, different aggregation ring layers access the backbone ring layer 110 through the affiliated core node.

Taking the example that the transmission network system 10 for rail transit includes two aggregation ring network layers 120, as shown in fig. 3, the two aggregation ring network layers 120 respectively access the core switches 111-a in different core nodes to access the backbone ring network layer 110.

In order to implement service access, in a possible implementation manner of the embodiment of the present invention, the transport network system 10 for rail transit may further include a service access layer. The service access layer includes an access switch, each service subsystem in the communication system is accessed to the convergence ring network layer 120 through the access switch, and the convergence ring network layer 120 is accessed to the backbone ring network layer 110; each service subsystem in the signal system is accessed into the backbone ring network layer 110 through an access switch.

Specifically, an automatic train monitoring ATS subsystem and an automatic train protection ATP subsystem in a signal system are respectively connected with two access switches, one access switch is connected into a first loop, the other access switch is connected into a second loop, a train maintenance support MSS subsystem in the signal system is connected into one access switch, the access switch is connected into a backbone ring network layer 110, and signal service is connected into the backbone ring network through the access switch.

In order to ensure the safety and isolation of each signal service and avoid mutual interference among the signal services, each signal service can be independently accessed at a core node, and for ATS subsystem services and ATP subsystem services with higher importance, two access switches are respectively accessed to two core switches in the core node. The core switch divides a first loop and a second loop into five logic subnets by adopting a Virtual Local Area Network (VLAN) technology, the frequency bands of the logic subnets are different, an ATS subsystem and an ATP subsystem in the first loop are accessed, the ATS subsystem and the ATP subsystem in the second loop are respectively accessed into four logic subnets in the five logic subnets, and the MSS subsystem is accessed into the rest logic subnet in the logic subnets.

In order to facilitate understanding of the implementation process of accessing the aggregation ring layer 120 and the backbone ring layer 110 through the access switch in the embodiment of the present invention, the following description is made with reference to the accompanying drawings.

Fig. 4 is a schematic view of an access topology of a communication and signal service subsystem access network. In fig. 4, a core node is taken as an example, where a signal service and a communication service of a station service layer access a convergence ring network layer and a backbone ring network layer. As shown in fig. 4, the ATS service and the ATP service in the signal service of the station service layer are respectively accessed to the core switch 1 and the core switch 2 through two access switches to be accessed to the logical subnet divided by the VLAN technology, and because the core switch 1 and the core switch 2 respectively belong to different loops, the ATS service and the ATP service are also accessed to different loops, thereby achieving the purpose of redundancy backup. The MSS traffic is accessed to the core switch 2 through one of the access switches. Communication services such as public telephone service, OA service, AFC service and the like are connected with a convergence switch in the convergence ring network layer through an access switch so as to be accessed to the convergence ring network layer, and then the convergence ring network layer is accessed to the backbone ring network layer.

By accessing the ATS service and the ATP service with high importance degree into the first loop and the second loop, redundant backup of the ATS service and the ATP service can be realized, and the safety of service data is guaranteed. Because one port of the access switch can be regarded as a virtual local area network, when data is transmitted in the network, the access switch can not forward the data packet to other ports, thereby realizing the isolation between service data and ensuring the data safety.

Further, in a possible implementation manner of the embodiment of the present invention, a Multi-Protocol Label Switching (MPLS) Virtual Private Network (VPN) technology is supported between core switches in each core node, so that Multi-service communication of data, voice, image, and the like, which is cross-regional, safe, high-speed, and reliable, can be implemented.

Since the core node carries both the signal service and the transmission of the communication service, in order to make a graduation of the mutual interference between different services, it is necessary to make physical isolation of channels on hardware, so that the communication service and the signal service are transmitted separately. In this embodiment, a core switch in the core node may adopt a core switch including a plurality of boards, and each board is provided with a different virtual private network VPN instance, where different service subsystems in the communication system and the signal system correspond to different boards. Different services are accessed to different board cards for transmission, so that the isolation among different services can be realized, and the risk of mutual interference among the services is reduced to the minimum.

Further, in order to ensure reliability of transmission of each service data, in a possible implementation manner of the embodiment of the present invention, the transmission network system 10 for rail transit may further include a Bidirectional Forwarding Detection (BFD) device disposed between adjacent core switches, and configured to detect whether a network fault exists between the adjacent core switches, record a fault location of the network fault when the network fault is detected, and control a data stream to be switched from a current transmission path to a protection path for transmission. The protection path is reversely transmitted from a source node of the data stream to a destination node; or, the protection path is that the data stream is transmitted from the source node to the first node before the fault position, then transmitted from the first node to the source node, and then transmitted from the source node to the destination node in a reverse direction.

In this embodiment, the MPLS-VPN technology is supported between the core switches, and since MPLS supports ring network protection, and the ring network protection mode is as shown in fig. 5, when the transmission network is interrupted, fast transmission line switching can be implemented to ensure that the data stream continues to be transmitted.

The ring network protection mode supported by MPLS includes two modes of wrapping protection and steering protection. When the wrapping protection is started, the protection path is that the data stream is transmitted to a first node in front of a fault position from a source node, and then is transmitted to the source node from the first node and then is reversely transmitted to a destination node from the source node; when the steering protection is enabled, the protection path is transmitted from the source node of the data flow to the destination node in the reverse direction. As shown in fig. 5, the transmission path of the data stream is: when the BFD device detects that the link between the intermediate node 1 and the destination node is failed, the BFD device can start the wrapping protection or the stepping protection to switch the transmission path of the data flow. When the wrapping protection is started, the data stream is transmitted according to the transmission path of the intermediate node 1, the source node, the intermediate node 2, the intermediate node 3 and the destination node; when the steering protection is started, the data flow is transmitted according to the transmission path of the source node, the intermediate node 2, the intermediate node 3 and the destination node. Since the data flow continues to be transmitted from the source node back to the destination node when the steering protection is enabled, part of the data that has been transmitted from the source node to the intermediate node 1 before the failure is detected cannot reach the destination node, resulting in loss of this part of the data.

Network fault detection is carried out through adopting the BFD device, cooperates the integrated circuit board simultaneously, can realize that the transmission path at 50ms rank switches, effectively improves switching speed, realizes the quick self-healing looped netowrk protection.

The transmission network system for rail transit provided by the embodiment of the invention can be provided with a set of network management in the control center, so that the transmission network system has the functions of network management and self-diagnosis, and further can perform safety management, fault management, performance monitoring, system management and configuration management on the network.

Fig. 6 is a schematic diagram of a network topology of a transmission network system according to an embodiment of the present invention. As shown in fig. 6, the transmission network system includes four core nodes including a control center, two concentration stations, and a vehicle segment, each core node includes two core switches, one core switch of every two adjacent core nodes is connected to form a first loop, the other core switch of every two adjacent core nodes is connected to form a second loop, and the first loop and the second loop form a backbone loop network layer. Each station in fig. 6 is used as a non-core node, a convergence switch is arranged in each station, and the convergence switches in two adjacent stations are connected to form a convergence ring layer. As can be seen from fig. 6, the convergence ring network layer formed by the convergence switches in each station belonging to the control center is accessed to the backbone ring network layer through the core switch in the access control center, and the convergence ring network layer formed by the convergence switches in each station belonging to the convergence station is accessed to the backbone ring network layer through the core switch in the access convergence station.

In specific implementation, optical cables respectively laid on uplink and downlink lines can be used for networking, the optical fibers adopt ITU-TG.652D single-mode optical fibers, the working wavelength is 1310nm and 1550nm double-window wavelength, and the special communication optical cables provide the working wavelength. The optical cable inserts to each station, vehicle section and control center's communication equipment room, and when laying the optical cable, the interior distribution frame of cabinet can connect out with the tail optical fiber, can use the jumper connection between each switch. Two core switchboards are respectively arranged at the control center, the vehicle section/parking lot and each signal equipment centralized station to form a core backbone transmission network. The adopted core switch can be completely compatible with 10GE and 40GE Ethernet standards, the switching capacity is not less than 50Tbps (bps is bit rate), the packet forwarding capacity is not less than 8000Mpps (pps is a unit of packet forwarding rate, namely, each second of packet), and thus the gigabit interface full-line-speed forwarding is ensured. Access to communication traffic and signal traffic uses an access switch as an access layer. When the service is accessed, the service of the signal system is accessed by using two access switches to realize redundancy backup, each signal device of the centralized station is accessed into the two access switches, and the service of the communication systems such as the video monitoring system and the PIS system is accessed into other access switches. A convergence switch is configured at each station, the convergence switch is compatible with 10GE and 40GE Ethernet standards and has the switching capacity of 20.48Tbps, the switching capacity of the switch is not less than 20Tbps, and the packet forwarding capacity is not less than 5000Mpps, so that the gigabit interface full-line-speed forwarding is ensured. The adopted convergence switch can provide rich Ethernet interfaces of gigabit light, gigabit electricity, tera light, tera electricity and the like, the convergence switch of each station belonging to the same concentration station forms a convergence ring network, and the convergence ring network is accessed to a backbone transmission network through a core switch of the concentration station.

The transmission network system of the embodiment of the invention realizes a communication and signal transmission integrated service comprehensive transmission system by using IP networking, has less equipment compared with the communication and signal independent networking technology, can effectively reduce the implementation cost, and accords with the development direction of rail transit integration; by adopting the switch, three-layer networking is realized, the networking is flexible, the configuration is simple, the expandability is good, the cloud computing is supported, and the requirements of virtualization and cloud platform development can be better met.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

It should be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

In addition, functional units in the embodiments of the present invention may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

Claims

1. A transmission network system for rail transit, comprising:

the adjacent core switches are connected by the link by using a network protocol IP networking technology to form a backbone ring network layer; wherein the core node at a starting location is adjacent to the core node at an ending location;

the core node includes: the system comprises a control center node, at least one centralized station node and/or at least one vehicle section node, wherein each core node comprises a first core switch and a second core switch;

the link comprises a first link and a second link;

the adjacent first core switches are connected through a first link to form a first loop; adjacent second core switches are connected through a second link to form a second loop, and the first loop and the second loop form the backbone ring network layer;

the link comprises a first link and a second link;

the system further comprises: accessing at least one aggregation ring layer of the backbone ring layers at the core node;

the converging ring network layer comprises: the system comprises a convergence switch arranged in a non-core node and a third link connected with the convergence switch; the adjacent aggregation switches are connected by the third link by using the IP networking technology to form the aggregation ring network layer;

different convergence ring network layers are accessed to the backbone ring network layer through the affiliated core nodes;

the system also includes a service access layer, the service access layer including: accessing a switch; each service subsystem in the communication system is accessed to the convergence ring network layer through the access switch, and the convergence ring network layer is accessed to the backbone ring network layer; each service subsystem in the signal system is accessed into the backbone ring network layer through the access switch;

an automatic train monitoring ATS subsystem and an automatic train protection ATP subsystem in the signal system are respectively connected with two access switches, one access switch is connected into the first loop, and the other access switch is connected into the second loop;

a train maintenance support MSS subsystem in the signal system is accessed into one of the access switches;

the core switch divides the first loop and the second loop into five logical subnets by adopting VLAN technology, the frequency band of each logical subnet is different, the ATS subsystem and the ATP subsystem in the first loop are accessed, the ATS subsystem and the ATP subsystem in the second loop are respectively accessed into four logical subnets in the five logical subnets, and the MSS subsystem is accessed into the rest logical subnet.

2. The system of claim 1, wherein when one of the loops fails, data continues to be transmitted through the other loop.

3. The system according to any of claims 1-2, wherein multiprotocol label switching virtual private network technology is supported between said core switches.

4. The system of claim 3, wherein the core switch comprises: the system comprises a plurality of board cards, wherein different virtual private network VPN examples are arranged in each board card, and different service subsystems in a communication system and a signal system correspond to different board cards.

5. The system of any of claims 1-2, further comprising:

the bidirectional forwarding detection device is arranged between the adjacent core switches and used for detecting whether a network fault exists between the adjacent core switches or not, recording the fault position of the network fault when the network fault exists, and controlling the data flow to be switched from the current transmission path to the protection path for transmission.

6. The system of claim 5, wherein the protection path is a reverse transmission from a source node to a destination node of a data flow; or, the protection path is that the data stream is transmitted from the source node to a first node located before the fault location, then transmitted from the first node to the source node, and then transmitted from the source node to the destination node in a reverse direction.