JPH0260242A - Fault point searching equipment for optical repeating installation - Google Patents

Abstract

PURPOSE:To standardize the disconnection section of an optical fiber cable and an optical relaying equipment in which a pulse code error rate is deteriorated at low cost and with less power consumption by transmitting a pulse pattern inherent to the optical relaying equipment to an optical transmission circuit on an output side as an optical signal when the optical relaying equipment does not receive an input signal. CONSTITUTION:The optical signal transmitted from the optical fiber cable 1 for an incoming transmission line is converted into an electric signal, identified and reproduced in a light- receiving circuit 2 in the optical intermediate relaying equipment 14. The electric signal is again converted into the optical signal in the optical transmission circuit 3, and transmitted to the optical fiber cable 4. A outgoing transmission line is the same. When the optical fiber cable 1 is disconnected, the light-receiving circuit 2 detects the disconnection of light reception and transmits a detection signal to a timer 5. The timer 5 transmits a control signal to a pulse pattern generator 6 at the period of intervals for specified T seconds for X periods. The pulse pattern generator 6 generates the characteristic pulse pattern and supplies it to the light transmission circuit 3 in response to the control signal. The light transmission circuit 3 converts the pulse pattern into the optical signal and transmits it to the optical fiber cable 4 at the period of the intervals of T seconds for X seconds.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a failure point searching device for an optical relay transmission system.
In particular, a failure point search device that makes it possible to locate optical fiber cable disconnected sections and optical repeaters with worsened pulse code error rates.

(Prior Art) Conventionally, a wide variety of devices have been proposed as failure point searching devices for this type of optical repeater.

(Problems to be Solved by the Invention) However, the conventional failure point search device for an optical relay transmission system has disadvantages in that it has a large circuit scale, is uneconomical, and consumes a large amount of power.

(Means for Solving the Problems) A fault point searching device for an optical repeater according to the present invention performs predetermined processing on an input optical signal received via an optical transmission line.
An optical repeater that sends out an output optical signal to the next optical transmission line detects non-reception of the input optical signal, and in response to this detection, pulses are generated for failure detection unique to the optical repeater at predetermined time intervals. Means for generating a pattern and transmitting it to the next optical transmission line is provided, and a fault point is searched for based on the presence of the fault searching pulse pattern.

(Example) Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a failure point search device showing one embodiment of the present invention.

The optical signal transmitted from the optical fiber cable 1 of the uplink transmission path is converted into an electrical signal and identified and regenerated by the optical receiving circuit 2 in the optical terminal relay device 14.

Thereafter, the signal is converted back into an optical signal by the optical transmission circuit 3 and sent to the optical fiber cable 4. Similarly, the optical signal transmitted from the optical fiber cable 8 on the down transmission line is converted into an electrical signal and identified and regenerated by the optical reception circuit 9, and then converted into an optical signal by the optical transmission circuit 10 and sent to the optical fiber cable 11. be done.

Now, considering the case where the optical fiber cable 1 is disconnected, the optical receiving circuit 2 detects the optical reception disconnection due to the disconnection of the optical fiber cable 1, and transmits the optical reception disconnection detection signal to the timer 5.
Send to. When the timer 5 receives the optical reception interruption detection signal, it sends a control signal to the pulse pattern generator 6 at a constant interval of T seconds for X seconds. A pulse pattern generator 6 that generates a unique pulse pattern at the same transmission speed and code rule as the transmission signal generates a unique pulse pattern in response to a control signal from the timer 5 and supplies it to the optical transmission circuit 3. The optical transmission port l1I83 converts this pulse pattern into an optical signal, and the unique pulse pattern converted into the optical signal is transmitted to the optical fiber cable 4 at a period of X seconds at an interval of T seconds. Here, the frequency oscillator 7 is provided so that the clock cannot be extracted from the optical signal from the optical fiber cable 1 in the case of optical reception cutoff, and is provided in a predetermined manner in the timer 5.12 and the pulse pattern generator 6.13. Supply a frequency clock.

When the disconnection of the optical fiber cable 1 is restored, the optical receiving circuit 2 detects the optical signal via the optical fiber cable 1, so the timer 5 is reset. The transmission signal identified and regenerated by the optical receiving circuit 2 is converted into an optical signal by the optical transmitting circuit 3 and sent to the optical fiber cable 4'.

Note that even if the optical fiber cable 8 is disconnected and restored, the timer 12 and pulse pattern generator 13 are activated in the same way as above.
operates to send out a unique pulse pattern.

FIG. 2 is a block diagram of an optical relay transmission system according to an embodiment of the present invention.

Optical terminal relay device T1. T2 is installed at both end stations of the optical fiber cable relay transmission line, and the fault point search circuit of the present invention is added to the optical fiber cable relay transmission line.

The optical signal sent from the optical terminal repeater T1 is transmitted through the optical fiber cable L1 of the uplink transmission line, and the optical signal attenuated on the transmission line is identified and regenerated by the optical intermediate repeater R1 and sent to the optical fiber cable L2. Ru. Hereinafter, similarly, the optical signals relayed and transmitted by the optical repeaters R2 and R3 are transmitted through the optical fiber cable L4 to the optical terminal station manufactured by Nakasha! Received at T2. On the other hand, the optical signal sent from the optical terminal station ffT2 made by Chusha Co., Ltd. is transmitted through the downlink optical fiber cable L4-, and is identified and regenerated by ffR3 made by Chusha Co. The signal is received by the rIIT1 manufactured by Senpai Manchusha Co., Ltd. via the optical fiber cable L1-.

If the optical fiber cable L1 is disconnected here, the optical reception disconnection is detected by the upstream optical transceiver board A1 of the optical intermediate repeater R1, and the unique pulse pattern FAI is transmitted at a certain interval of T seconds for X seconds. The signal is sent to the optical fiber cable L2, and is relayed as described above to the optical terminal relay device T.
Received at 2.

After X seconds, the unique pulse pattern P from the optical transceiver panel A1
AI transmission is stopped. Due to this stop, the upstream optical transmitter/receiver panel A2 of the optical intermediate repeater R2 detects the interruption of optical reception, and sends out a unique pulse pattern PA2 periodically for X seconds at intervals of T seconds to the optical fiber cable L3. This pulse pattern PA2 is received by the optical terminal relay device T2 through relay transmission by WIR manufactured by Hikari Chusha Co., Ltd. Similarly, after X seconds, the unique pulse pattern PA2 from the optical transceiver board A2
Since the transmission of the signal is stopped, the upstream optical transmitter/receiver board A3 of FFR3 manufactured by Hikari Chusha Co., Ltd. detects the interruption of optical reception, and sends out a unique pulse pattern PA3 to the optical fiber cable L4 at intervals of T seconds for X seconds. This pattern PA3 is received by the optical terminal station fiT2 made by Chusha Co., Ltd. 6M While the pulse pattern PAL starts to be transmitted at the upstream optical transceiver panel A1 of the optical intermediate repeater R1 that first detected the interruption of optical reception, the pulse pattern PAL is After seconds, the optical transceiver board A1 again sends out the pulse pattern PAL for X seconds. The pulse pattern PAI sent to the optical fiber cable L2 is received again by the optical terminal relay device T2 through relay transmission.

Optical transceiver panel A2. A3 detects the optical signal and the timer of each fault search circuit is reset.

Therefore, the pulse pattern PA2 is
．． PA3 is sequentially relayed and transmitted and received again by the optical terminal relay device T2.

FIG. 3(a) is a time chart of a unique pulse pattern train of each optical transceiver board received by the optical intermediate repeater T2 when the above-mentioned optical fiber cable L1 is disconnected. Pulse pattern PAL.

PA2. PA3 is transmitted sequentially at a repetition period of 1゛,
In the optical terminal relay device T2, the optical fiber cable disconnection section can be located by monitoring the presence or absence of transmission of the unique pulse pattern of each optical transceiver board set in advance.

In this example, optical transceiver boards AI, A2. Since the unique pulse pattern of A3 is being transmitted, it can be determined that a disconnection has occurred in the optical fiber cable L1.

FIG. 3(b) is a chime chart of the pulse patterns of each optical transceiver panel received by the optical intermediate repeater T2 when the optical fiber cable L2 is disconnected. Since the unique pulse pattern PAI of the optical transceiver board A1 is not transmitted, the cable l! It can be determined that the IT line section occurs in the optical fiber cable L2.

Furthermore, if the pulse code error rate of the transmission signal worsens due to deterioration of the optical transceiver board, the deteriorated optical transceiver board can be located using the following method. In Fig. 2, the optical terminal repeater] If the pulse code error rate of the signal transmitted from 1 to T2 worsens,
The connection with the optical fiber cable L1 connected to the optical terminal station relay device T1 is removed, and the optical fiber cable L1 is disconnected in a pseudo manner. As a result, the unique pulse pattern of each optical transceiver board shown in FIG. The pulse code error rate can be found. For example, if a pulse code error occurs in the optical transmitter/receiver A5 board A2, it can be determined that the code error rate of the transmitted pulse pattern A1 is getting worse. Also, code J on optical transceiver board A3! (If this occurs, it can be determined that the bit error rates of the transmitted pulse patterns PAI and PA2 are deteriorating.

(Effects of the Invention) As explained above, in the present invention, when an optical repeater does not receive an input optical signal, it sends a pulse pattern unique to the optical repeater to the output optical transmission line as an optical signal. This has the effect that the location of fiber cable disconnection sections and optical repeaters with worsened pulse code error rates can be realized at low cost and with low power consumption.

FIG. 1 is a block diagram showing an embodiment of a fault point search circuit according to the present invention, FIG. 2 is a block diagram showing an embodiment of an optical relay transmission system to which the present invention is applied, and FIGS. b
) is a time chart of the pulse pattern of each optical transmitter/receiver board received by the optical F41 station repeater.

1.4,8.11...Optical fiber cable, 2.9
...Optical receiving circuit, 3.10... Optical transmitting circuit, 512
...Timer 613...Pulse pattern generator,
7... Frequency oscillator, 14... Optical intermediate repeater.

Claims (1)

[Claims] An optical repeater that performs predetermined processing on an input optical signal received via an optical transmission line and sends it as an output optical signal to the next optical transmission line detects non-reception of the input optical signal, and In response, means is provided for generating a fault searching pulse pattern unique to the optical repeater at predetermined time intervals and transmitting it to the next optical transmission line, and searching for a fault point by the presence of the fault searching pulse pattern. A failure point search device for an optical relay device, characterized in that: