WO2020111335A1 - Method and device for monitoring ring-type optical network - Google Patents

Abstract

Disclosed is a method and device for monitoring a ring-type optical network. According to an aspect of the present embodiment, a method for monitoring a ring-type optical network by an in-house device comprises the steps of: generating a monitoring signal; converting the generated monitoring signal into an optical signal, and transmitting the converted optical signal; receiving the optical signal and converting the received optical signal into an electrical signal; and analyzing the converted electrical signal, wherein the monitoring signal includes a bit error rate (BER) code, a forward error correction (FEC) code, and a time code, and an ID.

Description

Ring type optical network monitoring method and apparatus

The present invention relates to a ring-type optical network monitoring method and apparatus.

The content described in this section merely provides background information for the present invention and does not constitute a prior art.

In a recent communication system, a base station uses a DU (Digital Unit) (or a BaseBand Unit) (hereinafter referred to as'DU' or'BBU') and a RU (Remote Unit) (or Remote Radio Head). (Hereinafter referred to as'RU' or'RRH'), DU and RU are separated and installed separately. In such a communication system, DUs are centralized in one place, and multiple RUs are connected to one DU. In this case, to reduce optical fiber cost, wavelength division multiplexing (WDM) (hereinafter referred to as'WDM') fronthaul equipment is used between the DU and the RU, and the operation of the equipment is stabilized. For this, the line redundancy method is applied. In implementing the WDM-type front hole equipment, the use of a remote terminal (RT) using a passive optical element that is easy to install and has fewer obstacles and defects is gradually expanding. However, in the case of a ring-type network using passive optical elements, switching in the clockwise or counterclockwise direction (or the first port or the second port) has been determined by using the sum of the optical powers of the lines, which causes the remote device to start before the service starts. There is a problem that there is no means to check the presence or absence of the installation, the installation location and the network structure.

Therefore, in order to grasp the installation location and structure of the remote device, the operator must directly grasp the location of the remote device and the ring-type network structure, and if the ring-type network structure is changed, it is difficult to directly modify and redistribute the ring-type network structure diagram. There was. Due to this, the information of the ring-type network structure in the field is less reliable, and there is a problem in that the service operation cost increases even in continuous management.

This embodiment has a main purpose in identifying a remote device in a ring-type optical network using a WDM method and determining a path for transmitting and receiving signals through switching. In addition, this embodiment has a main purpose to automatically grasp the structure of a ring-type optical network including the location of a remote device.

According to an aspect of the present embodiment, a method for monitoring a ring-type optical network by an in-house device includes generating a monitoring signal, converting the generated monitoring signal into an optical signal, and transmitting the received optical signal. Converting to an electrical signal, and analyzing the converted electrical signal, the monitoring signal includes a bit error rate (BER) code, forward error correction (FEC) code, time code, and ID .

According to another aspect of this embodiment, a domestic device for monitoring a ring-shaped optical network includes: a processor for generating a monitoring signal and analyzing a converted electrical signal, converting the generated monitoring signal into an optical signal, and transmitting the converted signal; 1 digital optical transceiver, and a second digital optical transceiver for receiving the optical signal and converting it into the electrical signal, the monitoring signal is a BER (Bit Error Rate) code, FEC (Forward Error Correction) code, Time code, And an ID.

As described above, according to the present embodiment, the device in the company can detect the abnormality of the line such as disconnection or twist by monitoring the optical power received in both directions, and operating the switch to reflect this to continuously operate the communication system. It can be done. Further, according to the present embodiment, even if the operator does not manually measure the distance to the remote device by using an OTDR (Optical Time Domain Reflectometer), it is possible to grasp the distance from the domestic device to the remote device.

1 is a diagram illustrating a communication system in which a device in a company and a plurality of remote devices are connected in a ring network structure through an optical path according to an embodiment of the present disclosure;

2 is a flowchart illustrating a device in a domestic company according to an embodiment of the present disclosure,

3 is a view showing the configuration of a device in a domestic company according to an embodiment of the present disclosure;

4 is a view showing a flow of a monitoring signal transmitted and received in a domestic device according to an embodiment of the present disclosure;

5 is a view showing the configuration of a remote device according to an embodiment of the present disclosure.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. It should be noted that in adding reference numerals to the components of each drawing, the same components have the same reference numerals as possible even though they are displayed on different drawings. In addition, in describing the present invention, when it is determined that detailed descriptions of related well-known structures or functions may obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the nature, order, or order of the component is not limited by the term. Throughout the specification, when a part is'included' or'equipped' a component, this means that other components may be further included rather than excluded, unless otherwise stated. . In addition,'… Terms such as "unit" and "module" mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software.

1 is a diagram illustrating a communication system in which a device in a company and a plurality of remote devices are connected in a ring-type optical network structure through an optical path according to an embodiment of the present disclosure.

Referring to FIG. 1, a base station of a communication system is divided into a BaseBand Unit (BBU) 110 (hereinafter'BBU') and a Remote Radio Head (RRH) (151, 152, 153, 154) (hereinafter'RRH'). Consists of. The BBU 110 is connected to a communication network through a backhaul, and the BBU 110 and RRHs 151, 152, 153, and 154 are connected to each other through a front hole, and RRHs 151, 152, and 153 , 154 is wirelessly connected to a terminal (not shown).

In addition, signals transmitted between the BBU 110 and the RRHs 151, 152, 153, and 154 are transmitted to a central office terminal (COT) 120 and a plurality of remote terminals (RT) 130. It is relayed through the formed ring type optical network. The domestic device 120 is connected to the BBU 110 to transmit and receive signals through a backhaul, and the remote device 133 is directly connected to each RRH or through a sub-remote device (SRT: Sub-RT) 142 It is connected to RRH (151, 152, 153, 154) and transmits a signal.

The domestic device 120 and the plurality of remote devices 130 are connected in a ring shape through one optical path, and the domestic device 120 performs two-way communication with the plurality of remote devices 130. The plurality of remote devices 130 is a passive node composed of passive elements, and distributes signals transmitted from the domestic device 120 or the RRH in such a ring-like network. In other words, the domestic device 120 transmits a down-link signal to the remote devices 131, 132, 133, 134 in both directions or one direction, and the remote devices 131, 132, 133, 134 The uplink signal is transmitted to the domestic device 120 in both directions or in one direction. In addition, the domestic device 120 receives the uplink signal from the remote devices 131, 132, 133, 134 in both directions or one way through the optical path to the distance to each remote device (131, 132, 133, 134). And a section where a failure has occurred.

Specifically, the domestic device 120 may transmit signals in both directions by wavelength division multiplexing a signal to be transmitted to each remote device 131, 132, 133, or 134. Each of the remote devices (131, 132, 133, 134), among the multiplexed signals, branch the signal of the wavelength assigned to it, and distribute it to the sub-remote devices (141, 142) or RRH directly connected to each remote device. Each remote device (131, 132, 133, 134) is provided with a switch therein can use only one of the signals in both directions.

On the other hand, in the ring-type optical network according to an embodiment of the present invention, since transmission of an uplink or downlink signal can be performed in both directions, even if a failure occurs in an optical path of any section of the connected optical path, the domestic device 120 may have multiple The remote device 130 may receive an uplink signal and each remote device 131, 132, 133, 134 may receive a downlink signal from the domestic device 120.

2 is a diagram illustrating a flowchart of an in-house device according to an embodiment of the present disclosure.

The domestic device generates a monitoring signal for monitoring the structure of the ring-shaped optical network (S210). The monitoring signal includes at least one of a bit error rate (BER) code, a forward error correction (FEC) code for correcting an error, a header for frame synchronization, a time code for distance measurement, and an ID for distinguishing a system and a remote device. One can be included. At this time, at least two monitoring signals are generated per remote device.

The domestic device converts the generated monitoring signal into an optical signal and transmits it (S220). Since the generated monitoring signal is an electrical signal, it is converted into an optical signal using a digital optical transceiver. The converted optical signal has at least two or more wavelengths per remote device, and is separated from the wavelength of the service signal.

On the other hand, the service signal is multiplexed only with the wavelength of the service signal, and is output from the optical switch in one direction of both directions of the ring-type optical network.

The domestic device receives the light signal reflected from the remote device and converts it into an electrical signal (S230). At this time, the reflected optical signal is an optical signal that is reflected by the remote device to the monitoring signal transmitted by the domestic device.

The domestic device analyzes the converted electrical signal (S240). First, the device in the domestic company checks the FEC code to determine whether there is an error, and if there is an error, corrects the error. In the absence of an error, the in-house device checks the time code to check the transmission time. Thereafter, the time transmitted by the time code is checked, and a clock counter up to the received time is multiplied by a clock period to obtain a transmission time, and the obtained transmission time is divided by the optical speed to calculate a distance from the domestic device to the remote device. Can be. In addition, the device in the company can confirm whether the network is properly connected by checking the ID. Specifically, the device in the domestic company may determine that the connection of the network is correct when the transmitted ID and the received ID are the same, but if it is not the same, the network connection may be twisted. In addition, the in-house device can monitor cutting and damage in both directions with the power of the received optical signal. That is, when the loss of the received optical signal power exceeds a threshold value or when the received optical signal power is below a reference value, the service can be maintained by changing the direction of the optical switch in view of damage to the optical path. However, if the power of the received optical signal is 0 in both directions, it may be determined that the domestic device does not have a remote device, or even if there is a remote device, the connection between the first port and the second port is switched with each other. .

The in-house device calculates the distance to the remote devices using the distance measurement value obtained from a plurality of monitoring signals, and arranges the remote devices in the same direction according to the distance. In addition, after aligning the distance measurement values obtained from the plurality of monitoring signals in the same direction, the difference between the neighboring distance values becomes the distance between the remote devices. As a result, the domestic device can grasp the structure of the ring-type optical network using the order and distance of the aligned remote devices.

In FIG. 2, it is described that the steps S210 to S240 are sequentially executed, but this is merely illustrative of the technical idea of an embodiment of the present invention. In other words, a person having ordinary knowledge in the technical field to which one embodiment of the present invention pertains may execute or change the order described in FIG. 2 without departing from the essential characteristics of one embodiment of the present invention, or one of the processes S210 to S240 Since the above process can be applied in various modifications and variations by executing in parallel, FIG. 2 is not limited to the time series order.

Meanwhile, the processes illustrated in FIG. 2 can be implemented as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data readable by a computer system is stored. That is, the computer-readable recording medium includes magnetic storage media (eg, ROM, floppy disk, hard disk, etc.), optical reading media (eg, CD-ROM, DVD, etc.) and carrier waves (eg, the Internet). Storage). In addition, the computer-readable recording medium can be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

3 is a diagram illustrating a configuration diagram of an in-house device according to an embodiment of the present disclosure.

In FIG. 3, the configuration is divided into a plurality of configurations, but multiple configurations may be integrated and implemented as one configuration, or a single configuration may be divided into multiple configurations. In addition, in describing the present disclosure, when it is determined that a detailed description of related known configurations or functions may obscure the subject matter of the present disclosure, the detailed description will be omitted.

The flow of the signal shown in FIG. 3 shows the flow of the optical signal converted from the electrical signal, which will be described below with reference to the optical signal.

The domestic device generates at least two monitoring signals per remote device. That is, the device in the domestic company generates at least two monitoring signals 310 and 315 to transmit to the bidirectional, that is, the first port 360 and the second port 365 because the network structure is ring-shaped. At this time, the generated monitoring signals 310 and 315 have different wavelengths.

The in-house device may transmit a service signal 320 in addition to the monitoring signals 310 and 315. The service signal 320 is multiplexed through the Mux/DeMux 330, and a direction in which the service signal 320 is to be transmitted is selected in one direction rather than in both directions through the optical switch 340. The service signal 320 may be multiplexed and transmitted through the monitoring signal and Mux/DeMux before transmission.

Specifically, referring to FIG. 3, the in-house device decides to transmit the service signal 320 using the first port 360 so that the service signal 320 is transmitted to the Mux/DeMux 350 using the optical switch 340. ). That is, a signal transmitted to the first port 360 transmits a monitoring signal and a service signal, and a signal transmitted to the second port 365 transmits only a monitoring signal.

In addition, the in-house device may receive signals received from a remote device through the first port 360 and the second port 365. As in the case of transmission, only one of the first port 360 and the second port 365 can receive a signal for monitoring reflected from the remote device, and the other port can receive the signal from the remote device. Reflected monitoring signals and service signals can be received. Here, the service signal received by the domestic device may be a signal corresponding to the transmitted service signal.

The signals for monitoring transmitted and received through the first port 360 and the second port 365 will be described in detail with reference to FIG. 4.

4 is a diagram illustrating a flow of a monitoring signal transmitted/received by an in-house device according to an embodiment of the present disclosure.

Referring to FIG. 4, the processor 410 of a domestic device generates two monitoring signals to be transmitted to a remote device using a BER & Time code generator/monitor. Since each of the generated monitoring signals is an electrical signal, it is converted into an optical signal through digital optical transceivers #1, #2 (420, 430). The converted optical signal is transmitted through ports M1 and M2.

Conversely, the in-house device may receive a monitoring signal transmitted from a remote device through the ports M1 and M2. Since the received monitoring signal is an optical signal, it is converted into an electrical signal through digital optical transceivers #1 and #2 (420, 430). The converted electrical signal can be confirmed through the BER & Time code generator/monitor of the processor 410.

Specifically, the BER & Time code generator/monitor includes a BER (Bit Error Rate) code, a Forward Error Correction (FEC) code for correcting an error, a header for frame synchronization, a Time code for distance measurement, a system and a remote device. Generated as a signal for monitoring to transmit at least one of the IDs for classification, and then analyzes received from the remote device. That is, the BER & Time code generator/monitor checks the FEC code to determine whether an error exists, and corrects the error if an error exists. If it is determined that the BER & Time code generator/monitor has no errors, check the time code to check the transmission time, check the time transmitted with the time code, multiply the clock counter to the received time by the clock period, and transmit time And calculates the distance from the domestic device to the remote device by dividing the obtained transmission time by the optical speed. In addition, the BER & Time code generator/monitor checks the ID to confirm that the network is properly connected.

5 is a diagram showing the configuration of an in-house device according to an embodiment of the present disclosure.

In FIG. 5, the configuration is divided into a plurality of configurations, but multiple configurations may be integrated and implemented as a single configuration, or a single configuration may be divided into multiple configurations. In addition, in describing the present disclosure, when it is determined that a detailed description of related known configurations or functions may obscure the subject matter of the present disclosure, the detailed description will be omitted.

3, the flow of the signal shown in FIG. 5 represents the flow of the optical signal converted from the electrical signal, and will be described below with reference to the optical signal.

The remote device may receive the optical signal transmitted from the domestic device using the first port 510 and the second port 515. The optical signal received using the first port 510 and the second port 515 is not the same signal, and a monitoring signal and a service signal are used as one of the ports, and a monitoring signal is used as the other port. To receive. Each signal received through the first port 510 and the second port 515 is first separated through Mux/ DeMux 520, 525, and the separated monitoring signals 550, 555 are mirrors 570, 575) and transmitted back to the in-house device through the first port 510 and the second port 515.

In addition, the service signals separated through the Mux/ DeMux 520 and 525 are coupled through the coupler 530 and connected to the Mux/DeMux 540. Thereafter, the multiplexed service signal 560 is transmitted to a sub-remote device or RRH connected to the remote device.

The above description is merely illustrative of the technical idea of the present embodiment, and those skilled in the art to which this embodiment belongs may be capable of various modifications and variations without departing from the essential characteristics of the present embodiment. Therefore, the present embodiments are not intended to limit the technical spirit of the present embodiment, but to explain, and the scope of the technical spirit of the present embodiment is not limited by these embodiments. The protection scope of the present embodiment should be interpreted by the claims below, and all technical spirits within the equivalent range should be interpreted as being included in the scope of the present embodiment.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims priority to US Patent Law No. 119(a) (35 USC §119(a)) with respect to Patent Application No. 10-2018-0151633 filed in Korea on November 30, 2018. All contents are incorporated into this patent application as a reference. In addition, this patent application claims priority to countries other than the United States for the same reason as above, and all the contents are incorporated into this patent application as a reference.

Claims (6)

1. A method for monitoring a ring-type optical network by a device in a company,

   The process of generating a signal for monitoring,

   Converting and transmitting the generated monitoring signal to an optical signal,

   A process of receiving an optical signal and converting it into an electrical signal, and

   And analyzing the converted electrical signal,

   The monitoring signal comprises a BER (Bit Error Rate) code, FEC (Forward Error Correction) code, Time code, and a network monitoring method characterized in that it comprises an ID.
2. According to claim 1,

   The process of generating the monitoring signal,

   Network monitoring method characterized in that the process of generating at least two monitoring signals for each remote device.
3. According to claim 1,

   The process of analyzing the converted electrical signal,

   Network monitoring method characterized in that the process of analyzing the structure of the network by calculating the distance to the remote device using the Time code included in the monitoring signal.
4. According to claim 1,

   And measuring the power of the received optical signal and determining that the network is disconnected if it is below a certain value.
5. According to claim 1,

   The process of analyzing the converted electrical signal,

   And determining that there is no remote device if the transmitted ID included in the monitoring signal is not included in the converted electrical signal.
6. In the domestic device for monitoring the ring optical network,

   Processor that generates a signal for monitoring and analyzes the converted electrical signal,

   A first digital optical transceiver for converting and transmitting the generated monitoring signal to an optical signal, and

   And a second digital optical transceiver that receives the optical signal and converts it into the electrical signal.

   The monitoring signal is a domestic device for monitoring a ring-type optical network, characterized in that it comprises a bit error rate (BER) code, forward error correction (FEC) code, time code, and ID.

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