JP2017103510A - Communication system, communication device and communication failure determination method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system, a receiver and a fault determination method, capable of detecting the cause of a communication abnormality in a distinguished manner to identify an abnormal point early and securely.SOLUTION: In a communication system 10 in which a first and a second communication device perform communication through a transmission line, a first communication device 20 includes: an electro-optic conversion unit which generates a transmission optical signal to be transmitted toward a second communication device 30 on the basis of a data signal; and a data insertion unit which inserts transmission intensity information which indicates the transmission intensity of the transmission optical signal into the data signal. The second communication device includes: a photoelectric conversion unit which converts the reception optical signal including the transmission intensity information into a reception electric signal; a data extraction unit which extracts the transmission intensity information from the reception electric signal; a measurement unit which measures the reception intensity of the reception optical signal; and a comparison and determination unit which, based on the transmission intensity and the reception intensity, determines a communication state between the first and second communication devices.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a communication system, a communication apparatus, and a communication failure determination method.

  For example, an optical communication system is a communication system that converts an electrical signal into an optical signal and transmits and receives information using the optical signal. For example, Patent Document 1 discloses a light input break detection system that detects a light break of an optical input signal and outputs an alarm signal.

Japanese Patent Laid-Open No. 10-229365

  For example, when a failure occurs in the photoelectric conversion function of the communication device, the communication device may generate a signal that is outside the communication standard. For example, when the strength of a signal used for communication falls below a predetermined level, the communication device may not be able to convert the signal into information (for example, voice or image).

  The above is an example of communication failure, but communication failure is caused by various factors. When a communication failure occurs, the maintenance manager identifies the cause of the failure and takes action. In order to resolve the failure at an early stage, it is required to identify the cause of the failure at an early stage, for example, to identify a defective part at an early stage.

  The present invention has been made in view of the above points, and is a communication system, a receiving device, a transmitting device, and a failure determination method capable of distinguishing and detecting the cause of a communication abnormality and identifying an abnormal part early and reliably. The purpose is to provide.

  The communication system according to the present invention is a communication system in which the first and second communication devices communicate via a transmission line, and the first communication device is directed to the second communication device based on the data signal. The second communication apparatus includes: an electro-optical conversion unit that generates a transmission optical signal to be transmitted; and a data insertion unit that inserts transmission intensity information indicating the transmission intensity of the transmission optical signal into the data signal. An optical-electric conversion unit that converts a received optical signal including information into a received electrical signal, a data extraction unit that extracts transmission intensity information from the received electrical signal, a measurement unit that measures the received intensity of the received optical signal, and a transmission intensity And a comparison / determination unit that determines a communication state between the first and second communication devices based on the reception intensity.

  Also, the receiving device according to the present invention is an optical-electrical conversion that converts a received optical signal that is transmitted from a transmitting device via a transmission path and includes transmission intensity information indicating transmission intensity at the time of signal transmission of the transmitting device into a received electrical signal. And a data extraction unit that extracts transmission intensity information from the received electrical signal, a measurement unit that measures the reception intensity of the received optical signal, and a communication state between the transmission apparatus and the transmission apparatus based on the transmission intensity and the reception intensity And a comparison / determination unit.

  The transmission device according to the present invention includes an electro-optical conversion unit that generates a transmission optical signal to be transmitted to the reception device based on a data signal, a measurement unit that measures the intensity of the transmission optical signal, and a measurement result of the measurement unit. A data generation unit that generates data including the transmission intensity information of the transmission optical signal and a data insertion unit that inserts the transmission intensity information into the data signal.

  The communication failure determination method according to the present invention measures the reception intensity of a received optical signal that is transmitted from a transmission apparatus to a reception apparatus via a transmission path and includes transmission intensity information indicating transmission intensity at the time of signal transmission of the transmission apparatus. A step of converting the received optical signal into a received electrical signal, a step of extracting transmission intensity information from the received electrical signal, and determining a communication state between the transmitting device and the receiving device based on the transmission strength and the received strength. And a step.

1 is a block diagram illustrating a configuration of a communication system according to a first embodiment. (A) And (b) is a figure which shows the structural example of the communication signal (The signal which a receiving device receives) in the communication system which concerns on Example 1. FIG. 3 is a failure determination flow of a receiving device in the communication system according to the first embodiment. It is a figure which shows the content of the failure determination in the communication system which concerns on Example 1. FIG.

  Examples of the present invention will be described in detail below.

  FIG. 1 is a block diagram illustrating a configuration of a communication system 10 according to the first embodiment. In the present embodiment, the communication system 10 has a configuration in which two communication devices (first and second communication devices) 20 and 30 communicate via the transmission path 40. In the present embodiment, the transmission line 40 is made of an optical fiber. That is, the communication devices 20 and 30 are optical communication devices, and the communication system 10 is an optical communication system.

  In the following, a case where the communication devices 20 and 30 are each connected to a terminal (not shown) and a data signal is transmitted from the communication device 20 to the communication device 30 will be described. That is, in the present embodiment, a case will be described in which the first communication device 20 functions (operates) as a transmission device and the second communication device 30 functions (operations) as a reception device. Hereinafter, the communication device 20 is referred to as a transmission device, and the communication device 30 is referred to as a reception device.

  The transmission apparatus 20 generates an optical signal (transmission optical signal) S03 to be transmitted to the reception apparatus 30 based on an electrical signal (data signal) S01 supplied from the outside (for example, a terminal). A conversion unit 21 is included. The EO conversion unit 21 includes, for example, a semiconductor laser. The data signal S01 is supplied from a terminal connected to the transmission device 20, for example. The transmission optical signal S03 is output from the transmission device 20 and transmitted to the reception device 30 via the transmission path 40.

  The reception device 30 receives the transmission optical signal S03 transmitted through the transmission path 40 as an optical signal (reception optical signal) S11. The receiving device 30 includes an OE (optical-electrical) converter 31 that converts a received optical signal (received optical signal) S11 into an electrical signal (received electrical signal) S13. The OE conversion unit 31 includes, for example, a photo detector. The received electrical signal S13 is supplied as an output electrical signal S15 via the data extraction unit 33, for example, to a terminal connected to the receiving device 30.

  The transmission device 20 includes a measurement unit 22 that measures the signal intensity of the transmission optical signal S03. More specifically, the transmission device 20 includes a branching unit JC1 that branches the transmission optical signal S04 for measurement from the transmission optical signal S03. The branch part JC1 is made of, for example, an optical coupler. The measurement unit 22 measures the signal intensity (for example, light intensity level) of the branched transmission optical signal (measurement signal) S04. For example, the measurement unit 22 measures the intensity of the measurement signal S04 for a predetermined period based on the input of the measurement signal S04. Further, the measurement unit 22 generates an electrical signal (transmission intensity signal) S05 indicating a measurement result, that is, a measurement value (transmission intensity) of the signal intensity of the measurement signal S04.

  Further, the transmission apparatus 20 includes a data generation unit 23 that generates signal intensity data of the transmission optical signal S03 based on the transmission intensity signal S05. For example, the data generation unit 23 generates an electric signal (insertion signal) S06 based on the communication method of the communication system 10 as the signal strength data. Further, the transmission device 20 includes a data insertion unit 24 that inserts the signal strength data (transmission strength information) of the transmission optical signal S03 into the data signal S01 based on the insertion signal S06. The data insertion unit 24 inserts transmission intensity data into the data signal S01 and generates a data signal S02 with transmission intensity information.

  The EO conversion unit 21 performs photoelectric conversion on the data signal S02 with transmission intensity information generated (inserted) by the data insertion unit 24. That is, the transmission optical signal S03 includes data (information) indicating the signal intensity of the transmission optical signal S03.

  The receiving device 30 includes a measuring unit 32 that measures the signal intensity of the received optical signal S11. More specifically, the receiving device 30 includes a branching unit JC2 that branches the received optical signal S12 for measurement from the received optical signal S11. The branch part JC2 is made of, for example, an optical coupler. The measuring unit 32 measures the signal intensity (for example, light intensity level) of the branched received optical signal (measurement signal) S12. In addition, the measurement unit 32 generates an electrical signal (reception strength signal) S16 indicating the measurement result, that is, the measurement value (reception strength) of the signal strength of the measurement signal S12.

  For example, the measurement unit 32 measures the intensity of the measurement signal S12 for a predetermined period based on the input of the measurement signal S12. The measurement unit 32 measures the signal intensity of the measurement signal S12 under the same conditions as the conditions under which the measurement unit 22 measures the intensity of the measurement signal S04.

  The reception device 30 includes a data extraction unit 33 that extracts data (transmission strength information) indicating the signal strength at the time of signal transmission in the transmission device 20, that is, the strength of the transmission optical signal S03, from the received electrical signal S13. Here, as described above, the received optical signal S11 includes data indicating the signal strength at the time of signal transmission of the transmission device 20. Therefore, the received electrical signal S13 obtained by converting the received optical signal S11 by the OE converter 31 includes transmission intensity information.

  The data extraction unit 33 extracts the transmission intensity data from the reception electrical signal S13, and generates an electrical signal (transmission intensity signal) S14 indicating the intensity of the transmission optical signal S03. For example, the signal S14 is a signal similar to the transmission intensity signal S05 generated by the measurement unit 22 in the transmission device 20.

  Further, the data extraction unit 33 generates an output electrical signal S15 obtained by extracting transmission intensity information data from the reception electrical signal S13 generated by the OE conversion unit 31. The output electrical signal S15 is transmitted to the terminal and is informationized by the terminal. That is, in the present embodiment, the data extraction unit 33 separates the transmission strength information from the received electrical signal S13 and supplies it to the comparison determination unit 34 as the transmission strength signal S14. On the other hand, the data extraction unit 33 generates an output electrical signal S15 that does not include transmission intensity information, and outputs it to the outside.

  The reception device 30 compares the reception intensity signal S16 generated by the measurement unit 32 with the transmission intensity signal S14 generated by the data extraction unit 33, and compares the communication state between the transmission device 20 and the reception device 30. The determination unit 34 is included. That is, the comparison determination unit 34 determines the communication state of the communication system 10 based on the strengths of both the communication signal at the time of transmission and the communication signal at the time of reception. The comparison / determination unit 34 generates an electrical signal (determination signal) S <b> 17 indicating the determination result of the communication state in the communication system 10.

  In addition, the receiving device 30 includes a reporting unit 35 that reports the communication state in the communication system 10 to the outside based on the determination signal S17. The reporting unit 35 generates a reporting signal S18 that reports the determination result of the comparison determining unit 34 to the outside. For example, when the determination signal 34 indicates a communication abnormality of the communication system 10, the notification unit 35 generates a notification signal S18 and outputs it to the outside. For example, the notification signal S18 is transmitted to the monitoring terminal.

  FIG. 2A is a diagram illustrating a received optical signal S11 received by the receiving device 30, that is, a signal format (format) of the transmitted optical signal S03 generated by the transmitting device 20. As shown in FIG. 2 (a), in this embodiment, the received optical signal S11 is a frame format (STM format) F1 of an STM (Synchronous Transfer Mode) format including a section overhead SOH and a virtual container VC. It is configured based on. That is, in the present embodiment, the communication system 10 is a communication system using an SDH (Synchronous Digital Hierarchy) system.

  The received optical signal S11 includes transmission intensity information TOP of the transmission device 20 in a portion corresponding to an empty byte (Z1 byte in the present embodiment) in the section overhead SOH of the STM format F1. In this embodiment, the transmission strength information TOP is generated as bit data by the data generation unit 23 and inserted into the section overhead SOH by the data insertion unit 24.

  Note that the format of the received optical signal S11 is not limited to the STM format F1. For example, FIG. 2B is a configuration example of the received optical signal S11A when the received optical signal S11A is configured based on the Ethernet (registered trademark) frame format F2. When the format F2 is used for the communication signal, the communication system 10 is a communication system using Ethernet (registered trademark). When the received optical signal S11A is used, the transmission intensity information TOP is added to a data portion in an Ethernet (registered trademark) frame, for example. In this way, the transmission intensity information TOP is inserted (added) into the transmission optical signal S03, that is, the reception optical signal S11 or S11A. The data extraction unit 33 of the reception device 30 extracts the transmission strength information TOP and supplies it to the comparison determination unit 34.

  In the present embodiment, as described above, the communication device 30 includes the measurement unit 32 that measures the intensity of the received optical signal S11. The communication device 30 is supplied with a received optical signal S11 including the signal strength of the communication device 20 during transmission, that is, the signal strength of the transmitted optical signal S03. In addition, the communication device 30 includes a comparison / determination unit 34 that determines a communication state of the communication system 10, for example, a communication failure, based on the signal strengths of both the transmission optical signal S03 and the reception optical signal S11. Therefore, for example, it is possible to distinguish and determine a transmission-side abnormality and a transmission line abnormality. As a result, it is possible to quickly and reliably identify an abnormal part when a communication failure occurs.

  FIG. 3 is a flowchart showing a failure determination flow of the receiving device 30. A communication failure determination method using the receiving device 30 will be described with reference to FIG. First, the receiving device 30 receives the received optical signal S11 with transmission intensity information TOP of the transmitting device 20 from the transmitting device 20 (step ST10). Next, the received optical signal S11 is branched by the branching unit JC2 (step ST20). Subsequently, the measurement unit 32 measures the intensity (reception intensity) of the branched received optical signal S12 (step ST30).

  Subsequently, the OE converter 31 performs photoelectric conversion on the received optical signal S11 to generate a received electrical signal S13 (step ST40). Next, the transmission strength information TOP is extracted from the received electrical signal S13 by the data extraction unit 33 (step ST50). Subsequently, the comparison determination unit 34 compares the measured reception intensity and the extracted transmission intensity to determine the communication state (for example, presence or absence of communication failure) (step ST60). Next, the reporting unit 35 reports the determination result to the outside (step ST70). In this way, the failure determination flow of the receiving device 30 ends (step ST80).

  In addition, when the failure has not arisen in the communication system 10, it is not necessary to report a determination result. That is, this flow can omit the reporting step ST70 in the presence or absence of communication failure.

  Through the above steps, the communication devices 20 and 30 can determine (monitor) a communication failure in the communication system 10 by comparing the signal strength at the time of transmission and the signal strength at the time of reception. Therefore, it is possible to detect the communication state in detail and to identify the abnormal part at an early stage when an abnormality occurs.

FIG. 4 is a diagram illustrating determination conditions and determination contents in the comparison determination unit 34 of the reception device 30. The determination content (determination result) of the comparison determination unit 34 will be described with reference to FIG. First, in the present embodiment, the receiving device 30 includes signal strength standards (upper and lower limits) A _max and A _min at the time of transmission by the transmitting device 20 and signal strength standards (upper and lower limits) at the time of reception by the receiving device 30. ) B _max and B _min and a threshold C set by the user, for example, are stored. Note that the transmitting device 20 and the receiving device 30 are provided with a member that attenuates light even in a normal communication state, such as branching portions JC1 and JC2 (optical couplers). The above upper and lower strength standards are set in consideration of the designed attenuation.

First, the comparison determination unit 34 compares the transmission strength measurement value A obtained by the extraction of the data extraction unit 33 with the transmission strength standard upper limit A _max and the transmission strength standard lower limit A _min (condition 1). The comparison determination unit 34 determines that an abnormality has occurred in the transmission device 20 when the transmission intensity measurement value A is less than the transmission standard lower limit A _min . Similarly, when the transmission strength measurement value A is larger than the transmission standard upper limit A _max , the comparison determination unit 34 determines that an abnormality has occurred in the transmission device 20. This is because a case where an abnormality has occurred in the transmission device 20 such as a case where an abnormality has occurred in the photoelectric conversion unit 21 of the transmission device 20 is assumed.

When the transmission strength measurement value A is within the range of the transmission strength standard upper limit A _max and the transmission strength standard lower limit A _{min in} the condition 1, the determination flow of the comparison determination unit 34 proceeds to the condition 2. Under condition 2, the comparison / determination unit 34 compares the received strength measurement value B obtained by the measurement of the measuring unit 32 with the received strength standard upper limit B _max and the received strength standard lower limit B _min . First, when the received strength measurement value B is greater than the received strength standard upper limit B _max or less than the received strength standard lower limit B _min , the comparison / determination unit 34 determines that an abnormality has occurred in the transmission path. This is because there may be a case where an abnormality has occurred in the transmission path, such as breakage of the transmission path (optical fiber).

In Condition 2, when the received strength measurement value B is within the range of the received strength standard upper limit B _max and the received strength standard lower limit B _min , the determination flow of the comparison determination unit 34 proceeds to Condition 3. Under condition 3, the comparison determination unit 34 compares the transmission strength measurement value A and the reception strength measurement value B. When the difference between the transmission strength measurement value A and the reception strength measurement value B is greater than the threshold value C, the comparison determination unit 34 determines that the transmission path has deteriorated. On the other hand, when the difference between the transmission strength measurement value A and the reception strength measurement value B is equal to or less than the threshold value C, the comparison determination unit 34 determines that the communication state is normal, that is, no communication failure has occurred.

  The comparison determination unit 34 supplies a determination signal S17 indicating these determination contents to the notification unit 35. The comparison determination unit 34 generates a different determination signal S17 for each determination content. The determination signal S17 includes the determination result by the comparison determination unit 34, the transmission intensity of the transmission optical signal S03, and the reception intensity of the reception optical signal S11. For example, when receiving the determination signal S17 except when the communication state is normal, the notification unit 35 outputs the notification signal S18 to the outside (for example, a monitoring terminal). For example, the notification unit 35 outputs a notification signal S18 indicating the determination result by the comparison determination unit 34, the transmission intensity of the transmission optical signal S03, and the reception intensity of the reception optical signal S11 to the outside.

  As described above, the comparison determination unit 34 uses both the transmission intensity and the reception intensity to determine, for example, an abnormality in the transmission device 20 and an abnormality in the transmission path. Therefore, it is possible to shorten the time for examining the abnormal part and the countermeasure time. Further, by outputting (reporting) the measurement values of each signal strength in addition to the determination contents, it is possible to provide a lot of determination materials to the administrator.

  In the present embodiment, in the communication system 10 in which the communication devices 20 and 30 are connected via a transmission line, the communication device 30 determines the communication state in the communication system 10 based on the signal strength at both transmission and reception. It has the comparison determination part 34 which determines. Therefore, it is possible to provide the communication system 10 that can determine the communication state in detail and identify an abnormal part at an early stage in the event of a failure.

  In the present embodiment, the case where the transmission apparatus 20 supplies the reception optical signal S11 with the transmission intensity information TOP has been described. However, the reception optical signal S11 is supplied to the reception apparatus 30 via another communication apparatus, for example. May be. Moreover, although the case where the communication device 20 includes the measurement unit 22 and the data generation unit 23 has been described, the insertion data may be generated by another device. In other words, the reception optical signal S11 including the transmission intensity information TOP may be supplied to the reception device 30. Moreover, although the case where the transmission optical signal S03 is transmitted to the reception device 30 has been described, the transmission optical signal S03 may be transmitted to another reception device. That is, only one of the transmission device 20 and the reception device 30 may be provided with a device and a member that complement the other function.

  Further, the case where the receiving device 30 includes the data extraction unit 33, the comparison determination unit 34, and the notification unit 35 has been described. However, other communication devices such as the communication device 20 may perform data extraction, measurement, and comparison determination. That is, the same effect can be obtained through a flow (step) as shown in FIG. In other words, by executing the steps shown in FIG. 3, it is possible to provide a failure determination method capable of detecting an abnormality in detail and identifying an abnormal part at an early stage.

  Moreover, although the case where the comparison determination unit 34 performs the determination operation as illustrated in FIG. 4 has been described, this determination operation (determination content) is merely an example. For example, in the present embodiment, the notification signal S18 includes information indicating the measured values of the transmission strength and the reception strength in addition to the determination result, so that various examinations can be performed on the maintenance manager side. Therefore, other determination contents can be set in the comparison determination unit 34 according to the actual connection configuration. These can be achieved by the comparison / determination unit 34 performing a failure determination based on both signal strengths before and after transmission. Further, for example, it is possible to make a more detailed determination including a plurality of other communication devices and the state of the communication device 30 itself.

  Moreover, although the case where the communication system 10 performs optical communication has been described in the present embodiment, the communication system 10 is not limited to the case where optical communication is performed. For example, the communication system 10 may be a system that performs telecommunications. In this case, it is not necessary to provide the photoelectric conversion unit in the transmission device 20 and the reception device 30. Moreover, the measurement part 22 should measure the intensity | strength of data signal S01, and the measurement part 32 should just measure the intensity | strength of the received data signal (reception electric signal).

10 Communication System 20 First Communication Device (Transmitter)
30 Second communication device (receiving device)
40 Transmission path S01 Data signal S03 Transmission optical signal S11 Reception optical signal S13 Reception electrical signal TOP Transmission intensity information 31 Photoelectric conversion unit 32 Measurement unit 33 Data extraction unit 34 Comparison determination unit 35 Notification unit

Claims (12)

A communication system in which the first and second communication devices communicate via a transmission line,
The first communication device generates an optical transmission signal to be transmitted to the second communication device based on a data signal, and indicates the transmission intensity of the transmission optical signal in the data signal A data insertion unit for inserting transmission strength information,
The second communication device includes an optical-electric conversion unit that converts a received optical signal including the transmission strength information into a received electrical signal, a data extraction unit that extracts the transmission strength information from the received electrical signal, and the reception A measurement unit that measures the reception intensity of an optical signal, and a comparison determination unit that determines a communication state between the first and second communication devices based on the transmission intensity and the reception intensity. Communication system.   The communication system according to claim 1, wherein the comparison determination unit generates a determination signal indicating a determination result that differs between an abnormality of the first communication device and an abnormality of the transmission path.   The first communication device generates a data including the transmission intensity information based on a measurement unit that measures the intensity of the transmission optical signal, and a measurement result of the measurement unit, and supplies the data to the data insertion unit The communication system according to claim 1, further comprising: a data generation unit that performs processing.   The communication system according to claim 2, wherein the second communication device includes a notification unit that notifies the determination result generated by the comparison determination unit to the outside.   The communication system according to claim 4, wherein the notification unit generates a notification signal indicating the determination result, the transmission strength, and the reception strength.   6. The received optical signal is configured based on an STM format, and the transmission intensity information is inserted into a free byte of a section overhead in the STM format. The communication system described. An optical-electric converter that converts a received optical signal that is transmitted from a transmission device via a transmission path and includes transmission intensity information indicating transmission intensity at the time of signal transmission of the transmission device into a received electrical signal;
A data extraction unit for extracting the transmission intensity information from the received electrical signal;
A measurement unit for measuring the reception intensity of the received optical signal;
And a comparison / determination unit that determines a communication state with the transmission device based on the transmission strength and the reception strength.   The receiving apparatus according to claim 7, wherein the comparison determination unit generates a determination signal indicating a determination result that differs between an abnormality of the transmission apparatus and an abnormality of the transmission path.   The receiving device according to claim 8, further comprising a reporting unit that reports the determination result generated by the comparison determination unit to the outside.   The receiving device according to claim 9, wherein the notification unit generates a notification signal indicating the determination result, the transmission strength, and the reception strength. An electro-optical converter that generates a transmission optical signal to be transmitted to the receiving device based on the data signal;
A measurement unit for measuring the intensity of the transmitted optical signal;
A data generation unit that generates data including transmission intensity information of the transmission optical signal based on a measurement result of the measurement unit;
And a data insertion unit that inserts the transmission intensity information into the data signal. Measuring the reception intensity of a received optical signal that is transmitted from a transmission apparatus to a reception apparatus via a transmission line and includes transmission intensity information indicating transmission intensity at the time of signal transmission of the transmission apparatus;
Converting the received optical signal into a received electrical signal;
Extracting the transmission intensity information from the received electrical signal;
Determining a communication state between the transmission device and the reception device based on the transmission strength and the reception strength.

Images