Transmission systems and transmission methods

Abstract

To provide a transmission system and transmission method that are excellent at preventing packet loss that may occur over long periods of time. [Solution] In the transmission system, the ETBN (Ethernet® Train Backbone Node) 14 comprises a first unit 30 having multiple ports connected to multiple trunk lines 10 and a switch IC 20 connected to the ports of the first unit via multiple branch lines. The first unit has a redundant connection that connects a port to which a trunk line is connected to a port to which a branch line is connected, or a bypass relay that relays a port to which a trunk line is connected to another port to which another trunk line is connected, and a second unit 34 that controls the switching of the bypass relay connection. The second unit has a supercapacitor 38 that is charged by a power supply from the trunk line and a relay controller that is driven by the power supply or the supercapacitor and controls the operation of the bypass relay.

Description

Technical Field

[0001] Embodiments of the present invention relate to a transmission system and a transmission method.

Background Art

[0002] In the backbone transmission of a vehicle Ethernet network, with the transmission of multimedia information in the vehicle, the communication speed of 100 Mbps has become insufficient, and the adoption of 1 Gbps lines has been increasing. As the transmission of multimedia information in the vehicle increases, the communication speed of 100 Mbps has become insufficient, and the adoption of 1 Gbps lines has been increasing. There is an increasing trend of adoption.

[0003] The Ethernet (registered trademark) standards for realizing a communication speed of 1 Gbps include 1000BASE-T and 1000BASE-Tx. E-T and 1000BASE-Tx exist.

[0004] In 1000BASE-T, transmission and reception are not physically separated, and transmission and reception are simultaneously performed in half-duplex communication using 4 pairs of cables. Transmission and reception are simultaneously performed in half-duplex communication.

[0005] On the other hand, in 1000BASE-Tx, like 100BASE-Tx, transmission and reception are physically separated, which makes the design of network devices easier than 1000BASE-T. However, for 1000BASE-Tx communication, a cable of Category 6 or higher is required. In 1000BASE-Tx, transmission and reception are physically separated, which makes the design of network devices easier than 1000BASE-T. However, for 1000BASE-Tx communication, a cable of Category 6 or higher is required. A cable of Category 6 or higher is required for 1000BASE-Tx communication.

[0006] [[ID=3…]] From the above, 1000BASE-T has become widely popular. Even in the 1 Gbps line of the vehicle Ethernet network, 1000BASE-T, which is adopted in RFC (request for comments) and is widely popular, is used. In the 1 Gbps line of the vehicle Ethernet network, 1000BASE-T, which is adopted in RFC (request for comments) and is widely popular, is used. In the case of a 1 Gbps line, since half-duplex communication is performed, if the power is cut off and suddenly connected by a bypass relay, the information on each transmission line cannot be synchronized, and it is difficult to recover.

[0007] In the case of a 1 Gbps line, since half-duplex communication is performed, if the power is cut off and suddenly connected by a bypass relay, the information on each transmission line cannot be synchronized, and it is difficult to recover. If the power is cut off and suddenly connected by a bypass relay, the information on each transmission line cannot be synchronized, and it is difficult to recover. In some cases, this can take about a minute. In railway vehicle transmission, such as brake control, Since we sometimes handle vehicle control, communication interruptions lasting seconds are unacceptable. Such behavior is not practical as a recovery procedure for redundant paths. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2018-101887 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The problem that this invention aims to solve is to provide an excellent solution for preventing packet loss that may occur over long periods of time. The objective is to provide a transmission system. [Means for solving the problem]

[0010] The transmission system of this embodiment has a first unit having multiple ports connected to multiple trunk lines. A knit and a switch IC connected to the port of the first unit via multiple branch wires. , comprising, the first unit, the port to which the main line is connected to the branch line A redundant connection is made to the port to which the main line is connected, or another main line connects to the port to which the main line is connected. A bypass relay that relays to other connected ports, and the connection of the bypass relay It has a second unit that controls the switching of connections, and the second unit is connected from the main line A supercharger that is driven by a supplied power supply and charged by the same power supply. The passiter and the bypass relay are driven by the power supply or the supercapacitor. It has a controller for controlling the operation of the [transmission system of the embodiment]. In the [transmission system], when an abnormality is detected, the controller sends a bypass switching notification to the trunk line and changes the switch of the bypass relay to relay connection. The bypass relay that has received the bypass switching notification discards the received bypass switching notification frame and temporarily disconnects the link with the switch IC and then reconnects it.

Brief Description of the Drawings

[0011] [Figure 1] FIG. 1 is a schematic diagram of 1Gbps trunk transmission of a vehicle. [Figure 2] FIG. 2 is a block diagram showing the schematic configuration of the switch IC according to the present embodiment. [Figure 3] FIG. 3 is a block diagram showing the normal operation of the transmission system of the present embodiment. [Figure 4] FIG. 4 is a schematic diagram of the internal configuration of the ETBN (Ethernet Train Backbone Node) according to the present embodiment and the first unit. [Figure 5] FIG. 5 is a diagram showing the operation of the second unit according to the present embodiment. [Figure 6] FIG. 6 is a block diagram showing the operation of the transmission system of the present embodiment during abnormality and power-off. [Figure 7] FIG. 7 is a flowchart showing the operation of the first unit during abnormality. [Figure 8] FIG. 8 is a diagram showing the control method during power-off.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments for carrying out the invention will be described.

[0013] (First Embodiment) The transmission system of the first embodiment will be described with reference to Figures 1 to 3.

[0014] Figure 1 is a schematic diagram of a 1Gbps trunk line transmission. Multiple ETBNs (E The thernet Train Backbone Node)14 is placed. Figure 1 shows Each vehicle is equipped with two ETBN14s, but there is no limit to the number of units that can be two or more.

[0015] The ETBN14 is a device for connecting a network of multiple vehicles and managing data communication. It is located. ETBN14 is a 1Gbps line connected by trunk line 10, and half Duplex communication is being performed. Data is transmitted appropriately from the source to the destination according to the train configuration. This enables efficient data transmission (dynamic routing) and ensures communication even during power failures. By providing a bypass relay 32 (see Figures 3 and 4) to maintain the connection between vehicles, Ensure communication and provide redundancy.

[0016] First, the switch IC20 according to this embodiment will be described with reference to Figure 2.

[0017] Figure 2 is a block diagram showing the schematic configuration of the switch IC 20 according to this embodiment.

[0018] As shown in Figure 2, the switch IC 20 of this embodiment includes a storage unit 22 and a controller unit It has 23, a switch unit 24, and a plurality of ports 26 (26-1 to 26-12).

[0019] The memory unit 22 is a non-volatile memory. The memory unit 22 controls the operation of the controller unit 23. It stores programs and other data.

[0020] The controller unit 23 has one or more CPUs (central processing This is a control unit including the controller unit. The controller unit 23 is the operation stored in the storage unit 22 It operates based on a control program, and the switch unit 24 switches the connection between ports 26. Control. That is, the controller unit 23 controls the operation control program stored in the memory unit 22. Based on this, the switch unit 24 controls the switching of connections between ports 26 according to various conditions. do.

[0021] The switch unit 24 disconnects the connection between ports 26 based on instructions from the controller unit 23. It's a circuit to be replaced.

[0022] Multiple ports 26 (26-1 to 26-12) are connected to multiple trunk lines 10 and multiple branch lines 12. The connection is established. As shown in Figures 2 and 3, ports 26-1 to 26-4 (top) are bypassed. It is connected to the main line 10 via relay 32, and ports 26-5 to 26-12 (lower) are branch lines 1 It is connected to 2. Ports 26-5 to 26-12 (lower part) connected to branch line 12 are as follows: It is connected to various devices. The number of ports 26 is not limited.

[0023] Switch IC20 is for link aggregation. It has the functionality to combine multiple physical links into a single logical link through link aggregation. Bundle them together.

[0024] Next, the normal operation of the trunk line redundancy control system will be explained with reference to Figure 3.

[0025] Figure 3 is a block diagram showing the normal operation of the transmission system in this embodiment. Bypass Relay 32 and switch IC 20 are connected via branch line 12. Under normal circumstances, bypass The relay of relay 32 never operates, and a 1Gbps redundant connection is established. The IPA relay 32 has multiple first ports (27-1~27) connected to multiple trunk lines 10. -4) A first group of ports 27 including and a second group of ports connected to a plurality of branch lines 12 ( It includes a second group of ports 28, including ports 28-1 to 28-4.

[0026] The trunk line transmission within the ETBN14 according to this embodiment will be described with reference to Figures 4 and 5. ru.

[0027] Figure 4 is a schematic diagram of the internal configuration of the ETBN14 and the first unit 30 according to this embodiment. Figure 5 is a diagram illustrating the operation of the second unit 34 according to this embodiment.

[0028] As shown in Figure 4, the inside of ETBN14 is the switch IC20 (integrated c ircuit) and the bypass relay 32 incorporate the necessary operating functions in case of abnormality. It has a unit 30 and a 1000BASE-T trunk line 10. Also, switch I C20 and the bypass relay 32 are connected by a branch wire 12.

[0029] The first unit 30 switches the bypass relay 32 and the connection of the bypass relay 32. It has a second control unit 34.

[0030] As shown in Figure 4, the second unit 34 is powered by a power supply (not shown) from the main line. The supercapacitor 38 is charged, and the power comes from the main line, or the supercapacitor... A CPU 40 powered by these power supplies, and a control program that controls the operation of the CPU 40. It has a relay controller 36 in which the data is stored. CPU 40 and relay controller 36 constitutes the controller. These second units 34 are configured in the event of a communication error or power failure. It is equipped with the necessary operating functions for the bypass relay 32 to operate in the event of a power source malfunction.

[0031] Furthermore, the relay controller 36 also has the function of controlling the operation of the switch IC 20. .

[0032] The supercapacitor 38 is normally charged by power supplied from the main line, When a power supply malfunction occurs, the power stored in the supercapacitor is used. It can supply enough power to operate a CPU and other components for several hundred milliseconds.

[0033] The CPU 40 is a main component of the control unit (controller), and the relay controller 3 The control device's operation is determined according to the program stored in the ROM (such as the one in unit 6).

[0034] Next, referring to Figure 5, the operation of the second unit 34 will be explained. Under normal circumstances, the main line or The second unit is driven by the power supplied from the supercapacitor. It's charged to 38.

[0035] Due to some kind of malfunction, the power supply to ETBN14 is cut off, or the branch lines of ETBN14 are affected. If a communication error occurs, the half-duplex communication on the communication path will be interrupted, and then the communication will be restored. This will take time. This is especially noticeable with 1Gbps half-duplex communication.

[0036] As shown in Figure 5, the supercapacitor 38 is charged in the event of a power supply malfunction or a communication malfunction. The power supplied drives the CPU40. The operation of this CPU40 enables the bypass relay. When relay 32 is activated and you specify either the redundant connection or the relay connection, switch 29 is switched off It will be replaced. That is, based on the specification of redundant connections, the predetermined first port 2 of the first port group will be replaced. Connect 7-1 to the designated second port 28-1 of the second port group, and specify relay connection. Based on this, the two first ports 27-1 and 27-4 of the first port group are connected. By connecting the main line ports of the IPA relay 32, the main lines are bypassed. This will enable communication on trunk line 10 to continue.

[0037] Next, with reference to Figure 6, the operation of the trunk route redundancy control system in the event of an abnormality will be explained.

[0038] Figure 6 shows the operation of the transmission system of this embodiment during communication failure and power outage. This is a diagram. Similar to Figure 3, the bypass relay 32 and the switch IC 20 are connected by the branch wire 12. It continues.

[0039] The program for the relay controller 36 specifies redundant connections in its initial state. However, if switch IC20 fails or port 26 connected to switch IC20 suddenly becomes unavailable... If communication with switch IC20 becomes impossible due to some factor such as loss of signal, When an abnormality is detected, such as when the power supply to ETBN14 is cut off, Bypass by the operation of the CPU 40 and relay controller 36 of the second unit 34. By operating relay 32, the main line 10 can be connected via relay. That is, see Figure 5. Activate switch 29 to connect ports 27-1 and 27-4. As shown in Figure 6, since the main lines are connected to each other, the connection status of the communication lines can be maintained. It is possible.

[0040] In the case of a 1000BASE-T line, transmission and reception are not physically separated, and the transmission signal It has become difficult to make a simple determination. Therefore, the bypass relay 32 is switched to change the transmission route. After the change, it takes a long time to return to the normal state, resulting in prolonged packet loss. It ends up happening.

[0041] In this embodiment, immediate restoration of transmission on the trunk line 10 is possible on a 1000BASE-T line. The specific operation will be explained with reference to Figure 7.

[0042] Figure 7 is a flowchart showing the operation of the first unit 30 in the event of an abnormality.

[0043] First, if communication with switch IC20 becomes impossible due to some factor, or ETBN If the power supply to 14 is cut off (S01), a special frame for abnormal situations will be displayed. As such, a bypass switching notification (frame) is sent from a port connected to the main line (S02 ). A bypass switching notification is received by the receiving switch IC20, and the first unit 3 on the transmitting side If the value is 0, the bypass will automatically close (S03).

[0044] In the receiving unit 30, when a bypass switching notification (frame) is sent, In conclusion, the frame is discarded (S05). This is because a frame that would not normally be received is sent. If the program remains active, the receiving CPU 40 may not perform as intended. However, However, there is no need to discard it.

[0045] After that, the link on the switch IC20 side is temporarily brought down and then reconnected. (10 (about 0ms) (S06) By following the steps above, each frame being transmitted will be reset and sent. Therefore, frame delimiter detection can be performed without any problems, and transmission and reception are not physically separated. Even with an unsupported 1000BASE-T line, no packet loss occurs. It is possible to immediately restore the transmission of 10 main lines within a few hundred milliseconds after an anomaly occurs.

[0046] Furthermore, a standard bypass relay 32 has a linked ON / OFF function for both the power supply and the relay. Because it is in operation, if the power is frequently turned on and off, unnecessary ON / OFF switching of the relay will occur. There is a risk that the relay may fail due to cracking. However, in this embodiment, In the control unit of the bypass relay 32, control is performed by the relay controller 36. To determine whether the bypass relay 32 is ON or OFF, it is basically only turned ON when an abnormality occurs. N / OFF is performed. Therefore, compared to using the normal bypass relay 32, ON / OFF The risk of failure due to FF (front-wheel drive) is extremely low.

[0047] When performing control as shown in Figures 6 and 7, the side receiving the bypass switching notification will use a dedicated bypass switch for abnormal situations. When a frame is received on any port, the link on the switch IC20 side is temporarily down. It will be controlled, but the intention is to perform that control on all ports. Port 26, on the side where the malfunction is occurring, has indeed brought the link down and reset the transmission. It is necessary to do so, but since the other port 26 is transmitting normally, there is no need to transmit unnecessarily. This will temporarily block the connection.

[0048] Therefore, referring to Figure 8, control that can minimize the impact on transmission in the event of an abnormality. Let's explain the method. Figure 8 shows the control method when the power is cut off.

[0049] Figure 8 shows that two ETBN14s are installed and connected by a main line 10.

[0050] For example, if switch IC20-1 fails, the bypass switching notification will be sent to the transmitting side. It is transmitted from. The control method shown in Figure 7 is a relay controller mounted on the control unit. In configuration 36, the control of the bypass relay 32 is divided into front and rear blocks. Adding frames divides the content into front and back blocks.

[0051] Therefore, only switch IC20-2 on the side containing port 26 is temporarily reset. It will be downgraded. In that case, the immediate restoration of trunk line transmission in case of abnormality will be met, while normal transmission This allows for control that minimizes impact without interfering with transmission.

[0052] Based on the above, this embodiment is a transmission system that is excellent in countermeasures against packet loss that may occur over long periods of time. We can provide systems and transmission methods.

[0053] Although several embodiments of the present invention have been described, these embodiments are presented as examples only. Therefore, it is not intended to limit the scope of the invention. These novel embodiments are It can be implemented in various other forms, and without departing from the spirit of the invention, various Omissions, substitutions, and modifications are permitted. These embodiments and their variations fall within the scope of the invention. It is included in the abstract and also within the scope of the invention described in the claims and its equivalents. . [Explanation of Symbols]

[0054] 10…Main line 12…branch line 14…ETBN 20…Switch IC 22...Storage section 23…Controller section 24... Switch section 26…Port 27…Port 1 28…Second port 29... Switch 30...First unit (control unit) 32... Bypass relay 34...Second unit (small unit) 36… Relay Controller 38…Supercapacitor 40…CPU

Claims

1. A first unit having multiple ports connected to multiple trunk lines, The system comprises a switch IC connected to the port of the first unit via a plurality of branch wires. 、 The first unit is, Redundancy: Connecting the port to which the main line is connected to the port to which the branch line is connected. Connecting a trunk line or a port to which one trunk line is connected to another port to which another trunk line is connected A bypass relay to be connected, A second unit that controls the switching of the connection of the bypass relay, It has, The second unit is, It is driven by a power supply from the main line and is charged by the power supply. supercapacitors and The power supply or the supercapacitor is driven, and the operation of the bypass relay The controller that controls it, A transmission system having

2. The first unit is, A first group of ports including a plurality of first ports connected to the plurality of trunk lines, A second group of ports, including a plurality of second ports connected to the plurality of branch lines, The controller has a predetermined first port of the first port group and the second port group. Redundant connection of the trunk route connecting to a predetermined second port, and the two of the first port group Specify one of the relay connections of the trunk route connecting the two first ports, Based on the designation of the redundant connection, a predetermined first port of the first port group and the second Connects to a predetermined second port of the port group, and the first port based on the relay connection specification. The group further has a switch connecting two first ports, The transmission system according to claim 1.

3. The controller, in its initial state, specifies a redundant connection and communicates with the switch IC. Based on the detection of a signal anomaly or a power anomaly from the main line, the connection is changed from redundant to relay connection. Specify The transmission system according to claim 2.

4. In the transmission system according to claim 3, When the controller detects an abnormality, it sends a bypass switching notification to the main line. Both systems change the bypass relay switch to a relay connection and receive the bypass switching notification. The bypass relay, after being deactivated, will downlink to the switch IC and then reconnect. The transmission method of a transmission system.

Images