KR101397299B1 - Method and apparatus for controlling transmitting and receiving frame in ring network applied hsr protocol - Google Patents

Abstract

A method and apparatus for improving traffic performance using a Traffic Control IED in a ring network to which the HSR protocol is applied is disclosed. According to the present invention, there is provided a method of controlling transmission and reception of a frame in a ring network to which HSR protocol is applied in which one of a plurality of intelligent electronic devices (IED) is set as traffic control IED (TCIED) Storing a previously received data frame on a first port of a transmitted data frame; Determining a maximum delay time of the data frame; And determining discarding and transmission of the stored data frame according to whether the data frame is received via the second port within the maximum delay time. According to the present invention, it is possible to safely transmit and receive data frames by significantly reducing the traffic load on the network, while assuring stability that the data frame can be safely transmitted in the network disconnection of the conventional HSR protocol.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for controlling frame transmission / reception in a ring network to which HSR protocol is applied,

Embodiments of the present invention relate to a method and apparatus for controlling frame transmission / reception in a ring network to which HSR protocol is applied. More particularly, the present invention relates to a method and apparatus for reducing a traffic load caused by frame transmission in an HSR network.

HSR (High-availability Seamless Redundancy) protocol is a proposed technology to recover ring network disconnection in a short time. It is characterized by short recovery time compared to other recovery protocols (recovery time: 'zero' time).

1 is a diagram illustrating a process of transmitting a data frame in a ring network to which a conventional HSR protocol is applied.

Referring to FIG. 1, a method of transmitting a data frame in a ring network to which a conventional HSR protocol is applied will be described in detail. Assuming that there are two ports in all Intelligent Electronic Devices (IEDs) in a ring network, The source IED transmits the same frame to the destination IED through each port so that even if a disconnection occurs in one link, the frame can be transmitted to the remaining one link. Therefore, the HSR protocol is characterized in that it takes no time to recover the ring network when it is disconnected.

FIG. 2 is a diagram illustrating a method of managing information of all IEDs existing in a network through a supervision frame in a ring network to which the conventional HSR protocol is applied, for example, in the case of IED3

Referring to FIG. 2, a method of managing information of all IEDs in a ring network to which the conventional HSR protocol is applied will be described in detail. The HSR protocol uses a system in which each IED in a ring network periodically exchanges supervision frames , The state of the entire network can be known through the transmission of the Supervision frame, and each IED stores information of different IEDs.

In order to guarantee a short recovery time and enable the transmission of the Supervision frame, the HSR protocol transmits the data frame and the Supervision frame, which each IED transmits in a bi-directional manner, To be discarded when reaching the opposite port of the IED.

However, this structure of the HSR protocol causes a lot of traffic load to the ring network, and there is a problem that data transmission may be delayed due to traffic load, or data may not be transmitted. Therefore, the HSR protocol is disadvantageous in that it can cause serious problems when applied to IEC 61850-based smart grid communication system, which is very sensitive to transmission time and recovery time.

In order to solve the above problems, the present invention proposes a method and apparatus for improving traffic performance in a ring network to which the HSR protocol is applied.

Other objects of the invention will be apparent to those skilled in the art from the following examples.

To achieve the above object, according to a preferred embodiment of the present invention, in a ring network in which one of a plurality of Intelligent Electronic Devices (IED) is set as a traffic control IED (TCIED), a TCIED transmits / CLAIMS What is claimed is: 1. A method comprising: storing a first received data frame on a first port of a data frame transmitted on a bidirectional port of a source IED; Determining a maximum delay time of the data frame; And determining discarding and transmission of the stored data frame according to whether the data frame is received via the second port within the maximum delay time.

And transmitting the stored data frame through the second port if the data frame is not received within the maximum delay time through the second port.

Discarding all of the data frames if the data frames transmitted from the source IED arrive at the first and second ports simultaneously or the data frames are received within the maximum delay time via the second port .

The maximum delay time may be determined according to at least one of a type of the data frame, a size of the data frame, a line speed, and a hop count between the source IED and the destination IED.

The maximum delay time may be determined by subtracting the maximum transmission time between the source IED and the TCIED from the sum of the maximum transmission time between the destination IED and the destination IED and the maximum transmission time between the destination IED and the TCIED in the source IED.

The maximum transmission time may be determined according to the following equation.

[Mathematical Expression]

Maximum Transmission Time

이며, Wire Speed는 회선 속도이다.Here, the transmission time (Transmission Time)

And Wire Speed is the line speed.

Transmitting a Supervision frame through the first and second ports; Receiving a response frame (Supervision Ack) frame including information of its own IED transmitted by each of the other IEDs receiving the supervision frame; And storing information about all the IEDs included in the ring network in the node table using the response frame.

It is possible to transmit the supervision frame at a predetermined period.

There is provided a computer-readable recording medium on which a program for performing the above-described method is recorded.

A traffic control device included in a ring network to which an HSR protocol is applied,

A transmitting and receiving unit transmitting and receiving a data frame through the first port and the second port;

A storage unit for storing a data frame received first through a first port of a data frame transmitted through the bidirectional port of the source IED; And

Determining a maximum delay time of the data frame after receiving the data frame and determining the discarding and transmission of the stored data frame according to whether the data frame is received through the second port within the maximum delay time A traffic control device is provided.

The controller may determine the maximum delay time using at least one of the type of the data frame, the size of the data frame, the line speed, and the hop count between the source IED and the destination IED.

The controller may determine the maximum delay time by subtracting the maximum transmission time between the source IED and the TCIED from the sum of the maximum transmission time between the destination IED and the destination IED and the maximum transmission time between the destination IED and the TCIED in the source IED.

According to the present invention, there is an advantage that the traffic load on the network can be remarkably reduced while ensuring stable transmission of data frames in the ring network of the HSR protocol.

1 is a diagram illustrating a process of transmitting a data frame in a ring network to which a conventional HSR protocol is applied.
FIG. 2 is a diagram illustrating a method of managing information of all IEDs existing in a network through a supervision frame in a ring network to which the conventional HSR protocol is applied, for example, in the case of IED3
3 is a flowchart illustrating an overall flow of a method for controlling frame transmission / reception in a ring network to which the HSR protocol is applied according to an exemplary embodiment of the present invention.
4 is a diagram illustrating a TCIED according to an embodiment of the present invention.
FIG. 5 is a diagram illustrating a case where a data frame is transmitted 1: 1 in a ring network to which an HSR protocol is applied according to an embodiment of the present invention, Fig.
FIG. 6 is a diagram illustrating a case where a data frame is transmitted 1: 1 in a ring network to which an HSR protocol is applied according to an embodiment of the present invention, and a data frame is transmitted using TCIED As shown in Fig.
FIG. 7 is a flowchart illustrating a method for transmitting a data frame in a one-to-many manner in a ring network to which an HSR protocol is applied according to an embodiment of the present invention. In a case where no error occurs during transmission, Fig.
FIG. 8 is a diagram illustrating a case where a data frame is transmitted in a one-to-many manner in a ring network to which an HSR protocol is applied according to an embodiment of the present invention. As shown in Fig.
9 is a diagram illustrating a method for managing information of all IEDs existing in a network in a ring network to which the HSR protocol is applied, according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

FIG. 3 is a flowchart illustrating an overall flow of a method for controlling frame transmission / reception in a ring network to which an HSR protocol is applied according to an exemplary embodiment of the present invention. FIG. 6 is a diagram illustrating a method of transmitting a data frame using a TCIED when a data frame is transmitted 1: 1 in a ring network and an error does not occur during transmission. FIG. 1 illustrates a method of transmitting a data frame using a TCIED when a data frame is transmitted 1: 1 in a ring network to which an HSR protocol is applied according to an embodiment, and an error occurs during transmission; to be.

Hereinafter, a method of controlling data frame transmission / reception in a ring network to which the HSR protocol is applied will be described in detail with reference to FIGS. 3, 5, and 6. FIG.

First, one of a plurality of IEDs is selected as a traffic control intelligent electronic device (TCIED) in a ring network to which an HSR protocol including a plurality of IEDs (Intelligent Electronic Device) is applied (step 301)

TCIED can be selected as an IED with relatively high CPU performance over a ring network.

Next, the method of managing TCIED frame transmission / reception differs depending on the type of frame, and it is determined whether transmission / reception of a supervision frame or transmission / reception of a data frame is performed (step 302).

In case of a data frame, if a data frame is received through the first port of the TCIED, the TCIED stores the data frame (step 303).

On the ring network, the source IED sends a data frame on a one-to-one basis to the destination IED, or a data frame on the bidirectional port of the source IED in order to transmit one-to-many data frames to destination IEDs.

Considering that the connection structure between the IEDs in the ring network is circular, if any one of the bidirectional data frames transmitted by the source IED is transmitted via all the IEDs on the ring network, the destination IED or destination IEDs It can be said that the data transmission is done correctly.

In this case, depending on the connection position between the source IED and the TCIED, the arrival time of the data frame through the bidirectional port of the source IED may be the same or different. The TCIED may simultaneously receive the data frame with its own bidirectional port, One data frame is received first.

If one of the data frames transmitted by the source IED through the bidirectional port is first received through the first port of the TCIED, then the TCIED does not transmit the data frame through the second port of the TCIED, Directional data frame transmitted to the IED of the ring network is transmitted twice to all the IEDs existing in the ring network.

Next, the timer is operated based on the time when the TCIED receives the data frame through the first port (step 304).

According to the present invention, the TCIED calculates the maximum delay time of the data frame at the time of the first reception of the data frame transmitted by the source IED through the bidirectional port, and operates the timer based on the calculated time.

When the reception of the data frame is delayed to the second port of the TCIED due to a trouble such as the ring network being disconnected by operating the timer, it is determined whether to transmit the data frame to the second port of the TCIED.

The TCIED determines whether the data frame is received within the maximum delay time through the second port (step 305).

The maximum delay time according to the present invention is such that after the data frame transmitted by the source IED is received at the first port of the TCIED, the data frame transmitted by the source IED is received by the second port of the TCIED, It means the waiting time that should be saved without transmitting to the port.

The maximum delay time is an important factor that must be computed to prevent a data frame transmitted from the source IED from being unnecessarily duplicated to the ring network.

Hereinafter, a calculation method of the maximum delay time will be described.

Parameter Value Wire Speed 100 Mbps Frame Size 180 Bytes Hop Count 1 or more

Table 1 shows an example of parameters required for calculating the maximum delay time.

The frame size refers to the size of a frame to be transmitted.

Wire Speed refers to the amount of data that a wire (communication wire, Wire) connecting IEDs in a ring network can transmit per second.

The Hop Count is the number of times a data frame has passed through a wire between adjacent IEDs, i. E., The total number of IEDs except IEDs transmitted from the IED to which the data frame was transmitted to the received IED.

Transmission time can be calculated by using the above-mentioned parameters according to the following equation (1).

Through this transmission time, the time required for data transmission between adjacent IEDs directly connected to the wire in the ring network can be calculated.

The maximum transmission time can be calculated using the transmission time and the hop count of Equation (1). The maximum transmission time can be calculated by Equation (2) below.

The maximum transmission time means a time required for transmitting a data frame between a receiving IED receiving a data frame and a transmitting IED transmitting a data frame. The transmission time and the hop count ). ≪ / RTI >

Finally, the maximum delay time that is calculated after the TCIED receives the first data frame from the source IED is the sum of the maximum transmission time between the source IED and the destination IED and the maximum transmission time between the destination IED and the TCIED, Can be calculated by subtracting the maximum transmission time between the source IED and the TCIED.

The maximum delay time calculated by the TCIED receiving the data frame at the first port can be calculated by Equation (3) below.

(SIED↔DIED) means the maximum delay time between the source IED and the destination IED, (DIED↔TCIED) means the maximum delay time between the destination IED and TCIED, and (SIED↔DIED) means the maximum delay time between the source IED and the TCIED Of the maximum delay time.

The maximum delay time is generally calculated in the same manner as in Equation (3), but may be varied according to the type of the data frame.

For example, in the case of a data frame in which real-time fast transmission is required, such as a voice data frame, the maximum delay time can be calculated in the same manner as in Equation (3) to ensure real-time communication.

However, in the case of a data frame in which real-time transmission is not required, such as a message data frame or an E-mail data frame, the maximum delay time may be set to be longer than the time calculated by Equation (3).

For example, a method of setting a maximum delay time for each data frame type is a method of multiplying a maximum delay time calculated according to a data frame type by a predetermined constant, You can set the time.

Next, if the data frame is received within the maximum delay time through the second port of the TCIED, the TCIED discards the stored data frame (step 306).

Referring to FIG. 5, after a data frame (A, B frame) is transmitted in two directions from a source IED, a data frame (B frame) reaches a TCIED first at a first port of TCIED and is stored in a storage section of TCIED A method is shown in which all data frames are discarded when a data frame (B frame) is received within a maximum delay time by the second port of the TCIED.

If the TCIED receives the data frame on the second port within the maximum delay time, it is guaranteed that the data frame has passed through all the IEDs in the ring network, and thus the destination IED in the ring network.

Accordingly, when the TCIED receives a data frame to the first port and then a data frame to the second port, the TCIED determines that the transmission of the data frame from the source IED to the destination IED has been performed, Thereby preventing transmission of unnecessary data frames.

When a TCIED simultaneously receives a data frame as a bidirectional port of the TCIED, the TCIED does not transmit the data frame but discards it.

The fact that a data frame is received on the bidirectional port of TCIED means that the data frame transmitted by the source IED is guaranteed to be transmitted to all IEDs including the destination IED through the inside of the ring network. This is because there is no need to transmit to the IED.

Thus, at this time, TCIED discards all non-storing data frames and reduces network traffic by not sending unnecessary data frames to the ring network.

If the data frame is not received within the maximum delay time at the second port of the TCIED, the TCIED transmits the received data frame through the second port without discarding the received data frame (step 307).

Referring to FIG. 6, a data frame (B frame) transmitted from the source IED may not be transmitted as TCIED due to an error during transmission.

In such a case, the TCIED can not confirm that the data frame has not been received within the maximum delay time and that the data frame transmitted from the source IED has passed through all the IEDs in the ring network, thus ensuring that the data frame is correctly transmitted to the destination IED Can not.

Therefore, TCIED transmits the stored data frame through the second port of TCIED.

Assuming that a data transmission error occurred in one part of the ring network, the data frame transmitted by the source IED can be securely transmitted to the destination IED by transmitting the data frame to the TCIED on the second port.

FIG. 7 is a flowchart illustrating a method for transmitting a data frame in a one-to-many manner in a ring network to which an HSR protocol is applied according to an embodiment of the present invention. In a case where no error occurs during transmission, FIG. 8 is a diagram illustrating a method of transmitting a data frame using TCIED when an error occurs during transmission. FIG.

As described above, when the TCIED receives the data frame transmitted from the source IED at the first port, it stores the data frame until the data frame is received at the second port, and i) If the frame arrives, all data frames are discarded. Ii) If the data frame does not reach the second port within the maximum delay time, the data frame is transmitted.

Through this method, the data frame transmitted by the source IED goes through all the IEDs in the ring network. In the same way as 1: 1 data transmission, it guarantees secure data transmission while reducing load on the network The method comprising:

When the frame transmission / reception is controlled using the TCIED in the ring network to which the HSR protocol is applied in the above-described method, the traffic load of the network can be remarkably reduced in a normal state in which the ring network is not disconnected, As with the conventional HSR protocol, secure data transmission is ensured.

In the above, a method of controlling data frame transmission / reception as a method for reducing a frame in a ring network to which the HSR protocol is applied has been described.

Hereinafter, a method for controlling all IEDs present in a network in a ring network to which the HSR protocol is applied, according to an embodiment of the present invention, will be described in detail with reference to the accompanying drawings.

3 is a flowchart illustrating an overall process of managing information of all IEDs existing in a network in a ring network to which the HSR protocol is applied according to an embodiment of the present invention. In the ring network to which the HSR protocol is applied, information of all IEDs present in the network is managed.

3 and 9, a method of managing information of all IEDs existing in a network through a method of transmitting a Supervision frame only by the TCIED in a ring network to which the HSR protocol is applied will be described in detail.

First, TCIED periodically transmits a Supervision frame including information of a Nodes Table stored in the TCIED to a bidirectional port (first and second ports).

In the present invention, only the TCIED allows a Supervision frame containing information of all IEDs in the network to be transmitted in both directions within the network, and the remaining IEDs on the network can only receive the Supervision frame transmitted by the TCIED and can not transmit the Supervision frame .

The TCIED transmits a Supervision frame at a preset cycle, which can be set differently depending on the characteristics of the network.

 Next, all the IEDs in the network receiving the Supervision frame transmit the Supervision Ack frame through the bidirectional port of each IED.

Each IED in the network can know the information of all IEDs in the network from the Supervision frame received from the TCIED. TCIED stores information about all IEDs in the network, updates information about all IEDs, and informs all IEDs that other IEDs in the network do not need to transmit Supervision frames and receive Supervision frames from TCIED An IED induces an update of information by transmitting a Supervision Ack frame containing information of its own IED.

Finally, the TCIED receiving the Supervision Ack frame from the IED in the network stores and updates (updates) information about all IEDs in the network to the node table in the TCIED.

The Nodes Table can contain various information such as Source Address (MAC Address) and Sequence Number of each IED in the network.

The information of the updated node table is transmitted when the TCIED transmits the Supervision frame to the IED in the network, and informs all the IEDs in the network about all the IEDs in the network.

In this manner, in the ring network to which the HSR protocol is applied, each IED transmits a Supervision Ack frame instead of transmitting a Supervision frame, and only TCIED only periodically transmits, stores, and updates information of all IEDs in the network ) Can reduce the traffic load in the network.

As described above, by using the TCIED in the ring network to which the HSR protocol is applied, the transmission of the data frame is controlled, and the transmission of the Supervision frame is restricted, It is possible to securely transmit and receive data frames by significantly reducing the traffic load on the network while ensuring stability that can be transmitted.

4 is a diagram illustrating a TCIED according to an embodiment of the present invention.

The TCIED includes a transmission / reception unit 401, a storage unit 402, and a control unit 403.

The transmission / reception unit 401 receives the data frame transmitted by the source IED, stores the received data frame on one port, and transmits the stored data frame when the data frame is not received on another port within the maximum delay time .

The storage unit 402 stores the data frame received from the source IED through one of the bidirectional ports (the first port).

When the data frame is received through the first port of the TCIED, the control unit 403 determines whether the data frame through the second port is received within the maximum delay time, and if i) the data frame is received within the maximum delay time , Removes the data frame, and ii) transmits the data frame to the second port if the data frame is not received within the maximum delay time.

The controller 403 controls the maximum delay time using at least one of a type of a data frame, a frame size, a wire speed, a source IED, and a hop count with the destination IED. (Maximum Delay Time).

The controller 403 determines whether the maximum delay time is a sum of the maximum transmission time between the source IED and the destination IED and the maximum transmission time between the destination IED and the TCIED, It can be determined by subtracting the maximum transmission time between IED and TCIED.

The controller 403 may include a timer for determining whether a frame is received within a maximum delay time.

The meanings of Transmission Time, Frame Size, Wire Speed, Hop Count, Maximum Transmission Time and Maximum Delay Time, And can be calculated by the above equations.

In the method of managing information of all IEDs existing in the network, the transceiver unit 401 transmits a Supervision frame including the information of the Node Table stored in the storage unit to the bidirectional port, and transmits the Supervision Ack Frame.

The storage unit 402 stores the Supervision Ack frame received from the source IED through one port (the first port) of the bidirectional port, and stores and updates information about all the IEDs in the network in the Node Table.

The control unit 403 controls to update all the IED information included in the Supervision Ack frames received from the IED on the network to the Nodes Table and controls the TCIED to transmit the Supervision frame to the network at a predetermined period.

Embodiments of the present invention may be implemented in the form of program instructions that can be executed on various computer means and recorded on a computer readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Examples of program instructions, such as magneto-optical and ROM, RAM, flash memory and the like, can be executed by a computer using an interpreter or the like, as well as machine code, Includes a high-level language code. The hardware devices described above may be configured to operate as one or more software modules to perform operations of one embodiment of the present invention, and vice versa.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and limited embodiments and drawings. However, it should be understood that the present invention is not limited to the above- Various modifications and variations may be made thereto by those skilled in the art to which the present invention pertains. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (12)

A method for controlling transmission and reception of a frame in a ring network to which HSR protocol is applied, wherein one of a plurality of Intelligent Electronic Devices (IEDs) is set as a traffic control IED (TCIED)
(a) storing a data frame received first through a first port of a data frame transmitted via a bidirectional port of a source IED;
(b) determining a maximum delay time of the data frame; And
(c) determining to discard or transmit the stored data frame according to whether the data frame is received via the second port within the maximum delay time. The method according to claim 1,
And if the data frame is not received within the maximum delay time through the second port in the step (c), transmitting the stored data frame after the step (c) through the second port Frame transmission / reception control method. The method according to claim 1,
(C) when the data frame transmitted from the source IED reaches the first and second ports at the same time, or when the data frame is received within the maximum delay time via the second port, And discarding all of the data frames after the frame transmission / reception step. The method according to claim 1,
Wherein the maximum delay time is determined according to at least one of a type of the data frame, a size of the data frame, a line speed, and a hop count between the source IED and the destination IED. 5. The method of claim 4,
Wherein the maximum delay time is determined by subtracting a maximum transmission time between the source IED and the TCIED from a sum of the maximum transmission time between the destination IED and the destination IED and the maximum transmission time between the destination IED and the TCIED in the source IED. 6. The method of claim 5,
Wherein the maximum transmission time is determined according to the following equation.
[Mathematical Expression]
Maximum Transmission Time

Here, the transmission time (Transmission Time)

, And Wire Speed is the line speed The method according to claim 1,
Prior to step (a)
Transmitting a Supervision frame through the first and second ports;
Receiving a response frame (Supervision Ack) frame including information of its own IED transmitted by each of the other IEDs receiving the supervision frame; And
And storing information about all IEDs included in the ring network in the node table using the response frame. 8. The method of claim 7,
And transmitting the supervision frame at a predetermined period. 9. A computer-readable recording medium on which a program for performing the method according to any one of claims 1 to 8 is recorded. A traffic control device included in a ring network to which an HSR protocol is applied,
A transmitting and receiving unit transmitting and receiving a data frame through the first port and the second port;
A storage unit for storing a data frame received first through a first port of a data frame transmitted through the bidirectional port of the source IED; And
Determining a maximum delay time of the data frame after receiving the data frame and determining the discarding and transmission of the stored data frame according to whether the data frame is received through the second port within the maximum delay time Traffic control device. 11. The method of claim 10,
Wherein the control unit determines the maximum delay time using at least one of a type of the data frame, a size of the data frame, a line speed, and a hop count between the source IED and the destination IED. 12. The method of claim 11,
Wherein the control unit subtracts the maximum transmission time between the source IED and the traffic control apparatus from the maximum transmission time between the destination IED and the traffic control apparatus and the maximum transmission time between the destination IED and the traffic control apparatus in the source IED, A traffic control device that determines.

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