JPH0618383B2 - Line supervisory controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a line supervisory control device for supervising and controlling a communication line, and more specifically, to superimpose a control signal and a supervisory signal on a main signal for transmission. The present invention relates to the line monitoring control device.

[Prior Art] In the field of wired communication in recent years, optical fibers have come to be used for communication lines. The amount of information that an optical fiber can carry is equivalent to thousands of copper cables when compared with a single cable, and it is possible to transmit 30 km at present without amplifying the information on the way. Suitable for sending large amounts of information over long distances.

In a communication line using such an optical fiber, it is necessary to monitor and control whether or not the line is operating normally, like the line using a conventional copper wire cable.

As a conventional line supervisory control device, in order to transmit control signals and supervisory signals, a system in which a specialized supervisory control line is provided separately from the main line that transmits the main signal, and the main line is shared as the supervisory control line, A method has been used in which a control signal and a supervisory signal are superimposed and transmitted on surplus bits provided in the signal.

[Problems to be Solved by the Invention] By the way, when the former method is applied to monitor and control a communication line using an optical fiber, a conventional copper wire cable is used as a monitor and control line installed in parallel with a main line. I can't. This is because the non-repeatered transmission distance of the copper wire is extremely short, which is one-tenth or less of that of the optical fiber, and it is meaningless to use the optical fiber as the main line. However, since it is not possible to separately provide a supervisory control line composed of an optical fiber, this method cannot be practically applied to supervisory control of an optical communication line.

In this respect, the latter method is suitable for the supervisory control of the above-mentioned optical communication line because it requires only the main line and does not require a transmission line dedicated to the supervisory control. However, since this method shares both lines, there is a problem in that if the main line fails, such as a line disconnection, the supervisory control function is lost at the same time as the main signal. Has the drawback of requiring special measures and laborious operations.

An object of the present invention is to provide a line supervisory control device capable of ensuring a supervisory control function even if a failure occurs in the shared line in a line supervisory control device that shares a main line and a supervisory control line. Especially.

[Means for Solving Problems] Means adopted by the present invention will be described.

A control signal from a line control device of one terminal station is superimposed on a main signal having a frame synchronization signal and a parity signal and transmitted through one line, and the control signal is separated in a relay device to correspond to the relay device. A monitoring signal from the monitoring device based on the control signal is superposed on the main signal transmitted from the other terminal station through the other circuit and transmitted to the line monitoring device of the one terminal station. In the line supervisory control device, an alternate signal is generated in each relay device that constitutes the line, (a) an alternate signal that has the same frame configuration as the transmission signal sent from the terminal station and that the parity signal violates the parity rule. Means, (b) an input signal loss detection means for detecting an input signal loss of the relay device, and (c) when the input signal loss of the interruption device is detected by the input signal loss detection means, the alternative signal generation means Output signal switching means for switching and outputting a signal generated from the stage as a relay device output signal.

[Operation] The alternative signal generating means of each relay device generates an alternative signal in which the frame configuration of the transmission signal transmitted from the terminal station is the same, and only the parity signal is a signal that violates the parity rule.

The input signal disconnection detecting means detects disconnection of a signal input to the relay device.

In the output signal switching means, when the input signal disconnection detecting means detects that the signal input to the relay device is disconnected, the signal generated by the substitute signal generating means is switched as the relay device output signal and output to the transmission path. To do.

When a line failure occurs and the reception input signal of the relay device is cut off as described above, the relay device that has detected the reception input signal disconnection has the same frame configuration of the transmission signal sent from the terminal station. In addition, since the alternative signal in which only the parity signal violates the parity rule is sent to the subsequent repeaters, each repeater separates the control signal and inserts the supervisory signal based on the frame synchronization signal of the alternative signal. It is possible to secure a line monitoring control function and detect a failure point.

Further, when the terminal station receives a signal that violates the parity rule, it can determine that it is not a signal from the subscriber and immediately stop transmitting the signal to the receiving subscriber.

[Embodiment] An embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a block diagram showing a configuration of a line supervisory control device of the present invention, FIG. 2 is a configuration diagram of a relay device showing an embodiment of the present invention, and FIG. 3 is a concrete example of a frame configuration of a transmission signal of the present invention. It is a figure which shows an example.

In FIG. 1, A and B are terminal stations, L _A is a line for transmitting a main signal from the terminal station A to the terminal station B, L _B is a line for transmitting a main signal from the terminal station B to the terminal station A, 11 and Reference numeral 12 is a terminal relay device, and 13 is a relay device installed in the middle. Generally, a plurality of relay devices exist, but in the figure, one relay device is shown as a representative.

The line control device 14 and the line monitoring device 15 are provided to the terminal stations A and B, and the monitoring devices 16 to 16 are provided to the relay devices 11 to 13.
18 is provided.

Also, the terminal station A and B, the switching device 19 is provided, the line L _A or L _B transmits to bypass the signal from the subscriber in the event of a failure in the line.

To the line L _A from the end station A, also a frame configuration of a transmission signal sent from the end station B on the line L _B, as shown in FIG. 3, the frame sync to transmit a frame synchronizing signal as a reference for multiplexing It comprises a working bit F _r , a data bit D _A for transmitting a communication signal, a parity bit P for checking a transmission error of the communication signal, and a surplus bit S _U for transmitting a supervisory control signal.

A control signal for each relay device is transmitted from the line control device 14A connected to the terminal station A, and the transmitted control signal is inserted into the surplus bit S _U described in FIG. It is transmitted to the relay apparatus via a line L _a. The monitoring signals from each of the relay devices based on the control signal is transmitted are inserted into the surplus bit S _U by line L _B to the terminal station A, to monitor the line are transferred to the line monitoring apparatus 15A.

Similarly, in the terminal station B, the control signal from the line control device 14B is inserted into the surplus bit S _U transmitted to the line L _B and transmitted to each relay device, and the monitoring from each relay device based on this control signal is performed. signals are transmitted using the excess bits transmitted to the line L _a to the terminal station B, it is transferred to the line monitoring apparatus 15B.

Insertion of the control signal and the supervisory signal into the surplus bit S _U is
The control signal is assigned the first half, for example, 8 bits of the surplus bits S _U , and the supervisory signal is assigned the second half, for example, 16 bits of the surplus bits S _U , and the control signal and the control signal are assigned using these assigned bits. The monitoring signal is transmitted.

Therefore, 8-bit first half of the redundancy bits of the transmission signal transmitted via the line L _A is the control signal sent from the line control device 14A is also a 16-bit in the second half of the excess bits of from the line control unit 14B A supervisory signal sent from each relay device is inserted based on the control signal and transferred to the line supervisory device 15B.

Also, 8-bit first half of the excess bits transmitted via the line L _B is a control signal sent from the line control unit 14B is also based on a control signal from the line control apparatus 14A in 16 bits of the second half each The supervisory signal sent from the relay device is inserted and transferred to the line supervisory device 15A.

Therefore, each relay device can be monitored and controlled by both the terminal station A and the terminal station B.

That is, the monitoring devices 16 to 16 connected to each relay device.
Reference numeral 18 indicates whether or not the status data of the respective relay devices, for example, the reception signal level received via the lines L _A and L _B is normal, and the transmission signal level transmitted to the lines L _A and L _B is normal. Whether the signal received via the lines L _A and L _B is disconnected, and whether the DC voltage supplied to the relay device is normal or not. Transferred from each part.

From the line control device 14A, the interruption devices 11, 13, ...
, 12 are sent out at regular intervals, for example, at intervals of 1 second, and control signals for sequentially instructing the transfer of the state data of each relay device. As the status data transfer command control signal to the relay device 11, for example, the device number 11 of the relay device 11 is set to 2
"0101111", which is a combination of "01011" represented by a 5-digit base number and a state data transfer request code, for example, "111"
1 ”of each bit from the first bit of the surplus bit S _U to the 8th bit
Insert in bit and transfer.

In addition, the state data transfer command control signal for the relay device 12 is "0110" in which the device number 12 is represented by a binary digit of 5 digits.
"0" and state data transfer request code "111"
8 bits of "100111" are inserted into the first to eighth bits of the surplus bits and transferred.

Each relay device transfers to the monitoring device by captures and first to eighth bits of the first half of the redundancy bits of the transmitted signal received from the line L _A and L _B.

The monitoring device 16 of the relay device 11 determines whether or not the data value of the first to fifth bits of the transferred signal is “01011”, which is the device number 11 of the own relay device 11 represented by a 5-digit binary number. If the determination is YES, the 6th to 8th bit codes are analyzed.

If sixth to eighth bits are "111", the status of each unit data of the relay apparatus 11, the control signal is different from the line came transmitted line, i.e., the control signal is transmitted by the line L _A If it comes, the 9th of the latter half of the surplus bit of the line L _B
~ Line monitoring device 1 by inserting status data in the 24th bit
Transfer to 5A.

The monitoring signal output from the monitoring device connected to each relay device is composed of a device number and status data. Taking the monitoring device 16 as an example, the device number “0101
1 ", followed by, _{L A} and _{L B} line receiving level" 11 "
( "1" if successful, "0" if abnormal), _{L A} and _{L B} line transmission level "11", _{L A} and _{L B} line signal loss "11", a total of 12 bits of the DC voltage "1" It is transmitted and inserted in the 9th to 20th bits of the surplus bit.

That is, if the relay device 11 is operating normally,
For the 20th bit, “01011111111111” is L _A
When the line signal is disconnected, the signal "0101111111011" is inserted.

The number of bits assigned to the surplus bits as the supervisory signal is 16 bits, of which 12 bits are used, and the remaining 4 bits are used for transmitting other supervisory signals.

When the supervisory signal is transferred to the line supervisory device 15 connected to the terminal station, it is first checked whether or not the first 5-bit device number matches the device number sent from the line control device 14, When they do not match, the control signal is sent again. Further, when the number of times of re-sending is, for example, 5 or more, the failure occurrence is output, and the control signal is sent to the next relay device.

When the device signals match, the device status corresponding to the transferred monitoring signal is output to monitor the line.

Next, the configuration and operation of each relay device will be described with reference to FIG.

FIG. 2 shows the configuration of the relay device 13, and other relay devices have the same configuration.

In FIG. 2, 13a is an uplink repeater that relays a signal to the line L _A , 13b is a downlink repeater that relays a signal to the line L _B , and the configuration thereof is the uplink repeater 13a. It has the same configuration.

The uplink repeater 13a includes a receiver 21, a control signal separator 22 that separates control signals, an alternative signal generator 23 that generates an alternative signal when a line failure occurs, and a signal received and reproduced by the receiver 21. Switch unit 2 for switching the alternative signal
4, an insertion unit 25 for inserting the monitoring signal from the monitoring device 18 into the surplus bits, and a transmission unit 26.

Receiving unit 21, the equalizing amplifier 31, the timing pulse extractor 32 for extracting a timing pulse from the received signal to correct the distortion of the signal passed through the line L _A, unipolar format digital signals transmitted in a bipolar form A double-wave rectifier 33 for converting into a signal, a pulse shaping circuit 34 for reproducing and outputting a received signal, and an integrating circuit 35.

The integration circuit 35 generates an integrated output of a certain value or more when a frame synchronization signal in which the signal "1" is continuous exists, but the line is disconnected and random signals of "1" and "0" are received. If it is, an integrated output below a certain value is generated. Therefore, if the integrated output is less than a certain value, it is determined that the line is disconnected and the determination result is sent to the switch unit 24.

The control signal separation unit 22 is composed of a synchronization circuit 36 and a separation circuit 37.

As described with reference to FIG. 3, the synchronization circuit 36 detects the frame synchronization signal from the transmitted signals to establish frame synchronization, and the first 8 bits of the surplus bit S _U (allocated to the transmission of the control signal). The transmitted signal is separated and transferred to the monitoring device 18.

As described above, the monitoring device 18 analyzes the first half 5-bit signal from the transferred signal, determines whether or not the code corresponds to the own relay device, and if it is not the own relay device,
If the transferred data is abandoned, and if it is the self-relay device, the subsequent 3-bit data is analyzed, and the supervisory signal corresponding to the control signal is inserted into the downlink relay unit 13b (not shown).
Send to.

The inserting unit 25 inserts the supervisory signal transmitted from the supervisory device 18 into the latter 16 bits (bits allocated for transmitting the supervisory signal) of the surplus bit S _U described in FIG. Send to.

The substitute signal generator 23 generates a substitute signal in synchronization with a timing pulse from a timing pulse extractor 32 (not shown) of the downlink repeater 13b.

The substitute signal generated by the substitute signal generator 23 is exactly the same as the frame structure of the transmission signal transmitted in the normal state. However, the parity bit P is a signal that violates the parity rule.

That is, in FIG. 3, the frame synchronization bit F _r
Contains "1011", which is the same as the frame sync signal in normal operation.
However, the data bit D _A has, for example, “10” as a pseudo signal.
10 parity signal against the parity law of the normal to signal ...... "is repeated parity bits P are also all due to the surplus bit S _U for inserting a monitoring signal from the monitoring device" 0 "Alternate A signal is generated by the alternative signal generation unit 23 and transferred to the switch unit 24. Switch part 24
Is composed of AND circuits 38 and 39, an inverter 40, and an OR circuit 41.

When the integrated value in the integrating circuit 35 is a certain value or more,
That is, when the received signal input through the line L _A is successfully received, the transmission signal that has passed through the control signal separation unit 22 is output to the insertion portion 25 through the AND circuit 38 and OR circuit 41 It

When the integration value of the integration circuit 35 is below a certain value, i.e., when the received signal input through the line L _A is detected as received signal loss, the output is "1" of the inverter 40, and the The substitute signal output from the substitute signal generator 23 is transmitted to the insertion unit 25 through the AND circuit 39 and the OR circuit 41. In this case, the transmission signal that has passed through the control signal separation unit 22 has the control terminal of the AND circuit 38 set to "0".
Therefore, passage through the AND circuit 38 is blocked.

Next, the line L _A at point X between the first view of the relay apparatus 11 and 13 will be described operation when a disconnection.

When the line L _A is the cross-sectional at point X, it is determined that the line disconnection by the integrating circuit 35 of the uplink relay of the relay device 13 to 12,
All the relay device sends the alternate signal output from the alternate signal generator 23 as mentioned above to the line L _A.

In this case, the integration circuit 35 of the relay device 13, as long as the radio link failure of the X point of the line L _A is not restored, and continue the determination of the line disconnection continues to sends the alternate signal.

However, in the relay device subsequent to the relay device 13, the substitute signal is transmitted from the relay device 13 and the same frame synchronization signal as in the normal state is received, so that the integrated output of the integration circuit 35 is sequentially set to a certain value. As described above, it is determined that the line is normal, and the alternative signal sent from the relay device 13 is reproduced, transmitted to the succeeding relay device, and sequentially relayed to the terminal station B.

Thus, the transfer of the monitoring signal based on the control signal from the terminal station A is susceptible transferred from all the relay devices because the line L _B is normal, the transfer of the control signal is to the relay device 11. That is, the terminal station A can perform line monitoring control up to the relay device 11.

Further, the control signal can be transferred from the terminal station B to all the relay devices, but the transfer of the supervisory signal from the relay device is performed by the relay device 13.
It is limited to the relay device between ~ 12. That is, the terminal station B can perform line monitoring control between the relay devices 13-12.

Therefore, as described above, the line control device 1 of the terminal station A
Although the relay device 11 responds to the status data transfer command control signal sent from 4A to each relay device, the other relay devices do not respond and the line failure can be known.

At the terminal station B, as described above, the relay device 1
3 from the reception level error and the line L _A break in the line L _A is transferred, thereby, it is possible to know that a fault has occurred between the relay apparatus 11 and 13.

Therefore, the end stations A and B, if normal transmission level of the line L _A of the relay apparatus 11 by the telephone connection, one of the receiving amplifier of the transmission path or the relay device 13 between the repeater 11 and 13 You can know that a failure has occurred.

Further, the same state occurs when a failure occurs in the transmission unit 26 of the relay device 11, but in this case, the terminal device A at the relay device 1
Since the transmission level abnormality of 1 is transferred, the failure point can be known.

Therefore, a fault in the line L _B, monitoring control of each relay side which exists between the lines L _A and L _B may both fails, similarly to fault point X and the terminal station A is Terminal A
Further, the terminal station B can monitor and control each relay device existing between the fault point X and the terminal station B.

Further, as described above, the substitute signal on the line L _A is transmitted by the relay station 13, signals transmitted to the terminal station B, since the signal against the parity law as described above is received,
A parity error occurs in all the received frames, and a switching signal is output to the switching device 19B by using the parity error as a trigger to switch the protection line to operate normally.

The terminal station B knows that a line failure has occurred due to this, and immediately disconnects the received signal from the subscriber and stops sending meaningless signals to the subscriber.

In addition, in addition to the embodiment, as a status data of each relay device, a parity check result of a transmission signal interrupted in the uplink and downlink relay units is also added, and the result is transferred to the terminal station as a supervisory signal. Since the parity error is transferred from all the relay devices whose signals are interrupted, the fault point can be detected also by this.

In the embodiment, the control signals are constantly transferred from the terminal stations A and B to the respective relay devices for line monitoring control.
One of the terminal stations A or B constantly performs line supervisory control, performs parity check of the transmission signal at both stations, sends a substitute signal when a line failure occurs, and sends a line error at both stations only when a parity error occurs. You may make it monitor-control.

[Effects of the Invention] As described above, according to the present invention, the following effects can be obtained.

When a line failure occurs and the reception input signal of the relay device is disconnected, the relay device in which the reception input signal disconnection is detected has the same frame configuration of the transmission signal transmitted from the terminal station,
Moreover, since only the parity signal sends an alternative signal that violates the parity rule to the succeeding repeater, each repeater separates the control signal and inserts the supervisory signal based on the frame synchronization signal of the alternative signal. It is possible to secure a monitoring control function and detect a failure point.

Further, when the terminal station receives a signal that violates the parity rule, it can determine that it is not a signal from the subscriber and immediately stop transmitting the signal to the receiving subscriber.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a line supervisory control device of the present invention, FIG. 2 is a configuration diagram of a relay device showing an embodiment of the present invention, and FIG. 3 is a concrete example of a frame configuration of a transmission signal of the present invention. The figure which shows an example. A, B ... Terminal station, 11, 12, 13 ... Relay device, 14
...... Line control device, 15 ...... Line monitoring device, 16-18
...... Monitoring device, 22 ... Control signal separation unit, 23 ... Alternative signal generation unit, 24 ... Switch unit, 25 ... Insertion unit, 32
...... Timing extraction circuit, 35 …… Integration circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naonobu Fujimoto 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (56) References JP-A-58-148548 (JP, A) JP-A-55- 132152 (JP, A)

Claims (1)

[Claims] 1. A control signal from a line control device of one terminal station is superposed on a main signal having a frame synchronization signal and a parity signal and transmitted through one line, and the control signal is separated in a relay device. The line monitoring device of the one terminal station is provided by passing the signal to the monitoring device corresponding to the relay device and superimposing the monitoring signal from the monitoring device based on the control signal on the main signal transmitted from the other terminal station through the other line. In the line supervisory control device that is configured to transmit to, the relay device that configures the line has (a) an alternative signal that has the same frame configuration as the transmission signal sent from the terminal station and whose parity signal violates the parity rule. Alternate signal generating means to be generated, (b) input signal disconnection detecting means for detecting input signal disconnection of the relay device, (c) when input signal disconnection of the interruption device is detected by the input signal disconnection detecting means, Generation An output signal switching means for switching and outputting a signal generated by a replacement signal generating means as a relay device output signal, and a line monitoring control device.