KR100729387B1 - Management solution to monitor the reflected fiber optic signal from the optic cable line to transfer the multichannel CWDM - Google Patents

Abstract

According to the present invention, when transmitting and receiving using the same wavelength in a CWDM (Coarse Wavelength Division Multiplexing) transmission system using an optical wavelength, an optical signal incident on an optical line of the system may be cut or terminated. Reflected optical signal is generated due to poor connection of the physical contact type connector used in the system. Since the reflected and reversed optical signal is input back to the transmission system, the optical signal is normally received in the management system. In some cases, it may not be possible to detect an error in transmission or data may not be transmitted through an optical signal. To monitor these problems and detect them early, add one channel in addition to the n channels for transmission used in low-density wavelength division multiplexing (CWDM) transmission systems so that the optical signal generated by reflection is incident on the added channel. The present invention relates to a method for monitoring a reflected light source of a multi-channel low density wavelength division multiplexing (CWDM) transmission system that detects a light signal reflected from a module and detects a malfunction due to reflection at an early stage so that the system can operate normally.

Low Density Wavelength Division Multiplexing (CWDM), Media Converter, Reflected Light, PC Type Connector

Description

 Management solution to monitor the reflected fiber optic signal from the optic cable line to transfer the multichannel CWDM}

1 is a conceptual diagram of an optical signal transmission apparatus of a low-density wavelength division multiplexing system operating normally according to the prior art.

2 is a conceptual diagram of an optical signal transmission device of a system malfunctioning due to reflected optical signals

3 is a conceptual diagram of an optical signal monitoring device for early detection of a reflected optical signal according to a preferred embodiment of the present invention

 <Description of Symbols for Major Parts of Drawings>

101: media conversion unit consisting of n channels 102: multiplexing / demultiplexing unit (MUX / DEMUX)

103: light path

201: n-channel media converter 202: multiplexer / demultiplexer (MUX / DEMUX)

203: optical line

204: an optical signal transmitted through an optical line

205: optical signal reflected from the optical line

301: media conversion unit consisting of n channels

302: new channel developed to receive reflected optical signal

303: multiplexing / demultiplexing unit (MUX / DEMUX) 304: PC type connector

305: optical path 306: optical signal transmitted through the optical path

307: optical signal reflected from the optical line

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The low density wavelength division multiplexing system is an efficient and economical optical subscriber network system for providing subscribers with high-speed, high-capacity Internet services including broadband multimedia services. Transmitting optical signals from the national office provides up to 100Mbps of bandwidth per channel, making it a very efficient Internet transmission system.

This system performs the demultiplexing function for the downlink optical signal and the media converter which converts the downlink Ethernet signal to the optical signal and the uplink optical signal to the Ethernet signal, and performs the multiplexing function for the uplink optical signal. Optical splitter (RN: Remote Node), a multiplexed demultiplexer, and an optical subscriber terminal (ONU) that converts a downlink optical signal into an Ethernet signal and converts an uplink Ethernet signal from a subscriber in service into an optical signal. Optical Network Unit). The maximum number of ports connected to the subscriber is 24 ports, which performs Layer 2 switch functions.

Conventional low density wavelength division multiplexed transmission methods transmit and receive at different wavelengths. Therefore, transmission and reception were possible through n / 2 channels at limited n optical wavelengths. Therefore, the conventional transmission method does not cause a problem due to reflection on the optical line but provides an n / 2 channel internet service.

In order to efficiently use optical wavelengths in the existing low density wavelength division multiplexing transmission scheme, the optical wavelength of the same channel is transmitted and received at the transmitting and receiving terminals by using the n optical wavelengths to expand to the n channels. However, when the same wavelength is used, an optical signal incident on the optical line is reflected and transmitted in the reverse direction of the transmission direction, and when the optical signal is input to the transmission system, an error may occur in the transmitted data or the data transmission may be stopped.

The present invention is designed to provide a high-speed, high-capacity Internet service, and to detect and detect the above-mentioned conventional problems early. In order to implement the present invention, the first part to be developed is to manufacture one additional channel for receiving the reflected optical signal in addition to the n channels for transmitting and receiving optical signals at the same wavelength in the multiplexing / demultiplexing unit. Since the optical signal transmitted from the transmitter is separated into n wavelengths for each channel and transmitted to the n channels, transmission is not performed through one additional channel. Since each channel is composed of a thin film filter, the optical splitter is manufactured to additionally manufacture one channel using the same method so that only the reflected optical signal passes.

In addition to n channels, one channel is added and the management program is installed so that the media converter can detect the reflected optical signal that has passed through the channel of the optical splitter. If the reflected optical signal enters the media converter, it can be detected immediately. It was.

According to the present invention, when a high-speed Internet service provider provides a service to a subscriber by using a multi-channel low density wavelength division multiplexing system, an optical signal transmitted to the subscriber passes through n channels in a media converter and is demultiplexed to be transmitted through an optical line And then provided to the subscriber via the optical subscriber terminal. In addition, the optical signal transmitted from the subscriber is transmitted to the media converter through the same process through the optical subscriber terminal.
When transmitting and receiving using the same wavelength, the optical signal incident on the optical line reflects the optical signal at the cut surface of the optical line and the optical connector end face due to the problem of cutting of the optical line and poor connector connection of the optical line. The reflected optical signal is returned to the media conversion unit through one optical channel additionally produced by the multiplexing / demultiplexing unit and transmitted to the additional reflection light monitoring media conversion unit. When the optical signal is transmitted to the additionally manufactured monitoring channel through the media conversion management system, the service provider can identify early that a problem has occurred in the optical line or the connector of the optical line, and the action can be taken promptly. It can be induced to work.
In order to implement the present invention, a monitoring channel for detecting a reflected optical signal in addition to the optical transmission channel must be added to the multiplexer / demultiplexer and the media converter, and a method to be detected by the media converter management module must be implemented.
* Description of the main parts of the drawings
1 is a conceptual diagram of an optical signal transmission apparatus of a low density wavelength division multiplexing system in normal operation;
Referring to FIG. 1, an optical signal transmission diagram of a conventional multi-channel low density wavelength division multiplexing passive optical subscriber network (CWDM-PON) system according to the related art is shown. Low density wavelength division multiplexing systems multiplex and demultiplex optical signals of different wavelengths to transmit and receive at the same wavelength. When the optical signal is transmitted, the multiplexer / demultiplexer 102 can transmit / receive using one optical line 103, and each light source and detector are configured to use one optical line 103. It is. The optical signal 104 transmitted from the transmitting end passes through the optical multiplexing unit 102 and enters the optical line 103, passes through the optical line 103, passes through the demultiplexing unit on the receiving end side, and is transmitted to the optical transmitting / receiving module. Then, the optical signal 104 is detected by the optical detector. At this time, the transmitted optical signal has no influence on the receiving end signal light source, and the optical signal coming from the other side is also transmitted to the transmitting end on the same principle. Therefore, even if the light source of the same wavelength is used in both directions, it can transmit without colliding with each other.
2) FIG. 2 is a conceptual diagram of an optical signal transmission device of a system malfunctioning due to reflected optical signals.
Referring to FIG. 2, the optical signal 205 reflected by the optical signal 204 transmitted from the low density wavelength division multiplexing system passing through the multiplexer 202 and incident on the optical line 203 proceeds in the reverse direction. If so, the reflected optical signal 205 is input to the media converter 201 again. The reflected light signal 205 is the same as the light signal normally received and is incident on the light transmission channel.
This results in many errors in the transmission of data in the transmission system and, in severe cases, leads to data transmission.
3) FIG. 3 is a conceptual diagram of an optical signal transmission apparatus for early sensing a reflected optical signal according to a preferred embodiment of the present invention.
Referring to FIG. 3, in addition to the media converter 301 including n transmission channels used in the low density wavelength division multiplexing system, one monitoring media converter 302 may be provided to the optical splitter and the media converter 301. Additionally connected. The monitoring channel to be added is different from the wavelength of the channel used for transmission.
Normally, the optical signal 306 transmitted from the demultiplexer 303 of the transmitting end is transmitted to the n transmission channels included in the media converter 301, but the reflected optical signal 307 is monitored media converter 302. Is added to one additional monitoring channel. The added surveillance optical signal has a new optical wavelength that does not affect the optical transmission system for transmitting data. The transmission system senses the optical signal that is transmitted with the added optical channel and then reflected back during the transmission. The manager early detects that a problem has occurred in the cutting of the optical line transmitted through the management device or the connection of the PC type connector used on the optical line.

1. The ability to monitor the reflection of optical signals on optical lines

The present invention distinguishes between the optical signal transmitted from the subscriber end and the optical signal reflected and returned during transmission, and detects the problem on the optical line early when the optical signal is reflected to induce the system to operate normally. Is that there is.

2. Supports many optical transmission channels of multichannel low density wavelength multiplexing system

Conventional transmission methods transmit and receive at different wavelengths due to the reflected optical signal. Therefore, it transmits and receives through n / 2 channels with n optical wavelengths and provides internet service with less channel. However, the present invention can detect and manage the reflected optical signal early, so that even when transmitting and receiving at the same wavelength, the reflected optical signal does not significantly affect the system or can be detected early. Therefore, it is possible to utilize n channels with n optical wavelengths, and more optical transmission channels can be used through the present invention.

Claims (3)

   An optical signal sensing device for early detection of reflection of an optical signal in a multi-channel low density wavelength division multiplexing passive optical subscriber network system,     A media converter converting the electrical Ethernet data signal into an optical signal;     Transmission unit for transmitting and receiving the optical signal transmitted by the media up-conversion unit: And    And a monitoring media converter configured to monitor the reflected optical signal including a reflected light monitor configured to transmit and receive an optical signal having a wavelength different from that of the transmitter.    The method of claim 1,   And the monitoring media converter is configured to transmit and receive the reflected optical signal through an additional optical channel.   In a multi-channel low density wavelength division multiplexing passive optical subscriber network system,   De-multiplexed the reflected optical signal due to at least one of a connector connection failure on the optical line, cutting of the optical line and poor fusion connection of the optical line, and transmits to the monitoring media conversion unit provided separately.    The reflected optical signal has a different wavelength from the transmission unit for transmitting and receiving the optical signal transmitted from the media conversion unit for converting the Ethernet data signal into the optical signal.

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