JP2657543B2 - Optical add / drop device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] Regarding an optical add / drop device, an optical add / drop device that branches and inserts an optical signal as it is, thereby simplifying the device configuration and increasing the speed and size of the device. In an optical add / drop multiplexer for dropping / adding a wavelength-multiplexed optical signal, it is an object of the present invention to provide an optical add / drop multiplexer for transmitting light of a wavelength including control information in the wavelength-multiplexed optical signal to a terminal or a subscriber. A wavelength demultiplexer that splits light having a wavelength to be output and light having another wavelength, a control unit that inputs light including control information from the wavelength demultiplexer, and extracts control information, A wavelength converter for converting the wavelength of light from the terminal or the subscriber according to control information; and a multiplexer for multiplexing the output of the wavelength converter and the light of the other wavelength from the wavelength demultiplexer. It is configured with.

[Industrial applications]

The present invention relates to an optical add / drop multiplexer, and more particularly to an optical add / drop multiplexer that drops and inserts a signal at an optical level.

[Conventional technology]

In the optical communication system, communication is performed between nodes by converting a large number of signals to be transmitted into optical signals and transmitting and receiving the signals via a plurality of nodes.

In such an optical communication system, it is desired that each node can drop and add the optical signal without converting the optical signal into an electric signal.

FIG. 3 shows a schematic block diagram of a conventional optical communication system, and particularly shows a schematic block diagram of an optical add / drop device provided at each node.

As shown in FIG. 3, an input optical signal time-division multiplexed by a large number of signals is converted into an electric signal in an optical / electrical conversion unit (O / E) 11 and added to a demultiplexing unit 12.

The demultiplexing unit 12 extracts a synchronization signal from the control signal (C) in the output electric signal of the photoelectric conversion unit 11 and performs channel (CH) identification, thereby obtaining data of each channel in the data signal (D). Separates the branch 13
To enter.

Under the control of the control unit 14, the branching unit 13 branches data of some channels and inputs the data to the electro-optical conversion unit (E / Os) 15, and sends signals of the remaining channels to the insertion unit 16.

As a result, the electro-optical converter 15 converts the electric signal of each channel split by the splitter 13 into an optical signal and sends out the generated optical signals CH _{a to} CH _d to the terminal or the subscriber.

On the other hand, the optical signal CH _I to CH _IV of each channel to be inserted into the node from the terminal or subscriber, the optical-electrical converter (O / E
s) It is added to 17, converted into an electric signal, and input to the insertion unit 16.

Under the control of the control unit 14, the insertion unit 16 inserts the data from the photoelectric conversion unit into the supported position and transmits the data to the multiplexing unit 18 to the data of each channel input from the branching unit 13 .

The multiplexing unit 18 multiplexes the data of each channel sent from the insertion unit 16, creates a data signal (D) and a control signal (C), and inputs them to the electro-optical conversion unit (E / O) 19. The electro-optical converter 19 converts the input electric signal into an optical signal, thereby generating a multiplexed optical signal output.

At this time, the control unit 14 controls the above-described branching / insertion processing in the branching unit 13 and the insertion unit 16 based on the synchronization signal and control information extracted from the control signal (C) in the demultiplexing unit 12. I do.

As described above, in the conventional optical communication system, when an optical signal is dropped or added, the transmitted optical signal is once converted into an electrical signal, and then the drop and insertion processing is performed in the state of the electrical signal. The optical signal is converted into an optical signal again and transmitted, thereby realizing branching and insertion of the optical signal.

For this reason, there has been a problem that the configuration of the apparatus is complicated, and it is inevitable that the speeding up and downsizing of the apparatus are hindered.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION The present invention is to solve such a problem of the prior art, and simplifies the device configuration by performing dropping and insertion of an optical signal in an optical add / drop device as it is, thereby achieving high-speed operation of the device. It is an object of the present invention to provide an optical add / drop multiplexer that can be made smaller and smaller.

[Means for solving the problem]

FIG. 1 is a schematic block diagram showing the basic configuration of the optical add / drop multiplexer of the present invention.

As shown in FIG. 1, the present invention comprises a demultiplexing means 101, a multiplexing means 102, and a wavelength converting means 103.

The demultiplexing unit 101 receives the wavelength-multiplexed optical signal,
The optical signal of a predetermined wavelength is branched and output.

The wavelength conversion means 103 performs wavelength conversion of an optical signal to be inserted according to control information extracted from the optical signal of the common wavelength (λ _c ) in the wavelength-multiplexed optical signal input to generate an optical signal output. Is what you do.

The multiplexing unit 102 inserts the output optical signal of the wavelength conversion unit 103 into the remaining optical signal that has not been split by the demultiplexing unit 101 to generate a wavelength-multiplexed optical signal output.

Accordingly, the configuration of the present invention is as described below. That is, in an optical add / drop multiplexer for dropping / adding a wavelength-multiplexed optical signal, light of a wavelength including control information in the wavelength-multiplexed optical signal, light of a wavelength to be output to a terminal or a subscriber, and other A wavelength demultiplexer (1) for splitting light having a wavelength, a control unit (14) for inputting light containing control information from the wavelength demultiplexer and extracting control information, and the control information from the control unit A wavelength converter (3) for converting the wavelength of light from the terminal or the subscriber, and a multiplexer for multiplexing the output of the wavelength converter and the light of the other wavelength from the wavelength demultiplexer. (2) The configuration as an optical add / drop multiplexer characterized by having (2).

[Action]

A wavelength to be branched is fixedly assigned to each node in advance, and the demultiplexing unit 101 branches an optical signal of a predetermined wavelength from the wavelength-multiplexed optical signal input and outputs the optical signal to a terminal or a subscriber or the like. At the same time, the remaining optical signal is sent to the multiplexing means 102.

On the other hand, since the wavelength-multiplexed optical signal includes an optical signal having a common wavelength that carries control information, the control information is extracted and provided to the wavelength conversion means 103.

The wavelength converter 103 converts the wavelength of the optical signal to be inserted at the node according to the given control information and outputs the converted signal.

The multiplexing means 102 inserts the output optical signal of the wavelength conversion means 103 into the remaining optical signals not split by the demultiplexing means 101 to generate a wavelength-multiplexed optical signal output which is the output of this node. I do.

As described above, the branching and insertion processing of the optical signal is performed in the wavelength region using the demultiplexing means, the multiplexing means, and the wavelength conversion means, and the wavelength conversion is controlled at the common wavelength. Can be added and dropped, thereby simplifying the configuration of the device, and increasing the speed and size of the device.

〔Example〕

FIG. 2 is a schematic block diagram of an optical add / drop multiplexer as one embodiment of the present invention, and particularly shows an example of the configuration of an optical add / drop device provided at each node. 1 is N (N is an arbitrary integer) wavelength demultiplexer, 2 is N
A wavelength multiplexer is shown, and 3 is a wavelength converter. Reference numeral 4 denotes a control unit.

In FIG. 2, the optical signal input is composed of signals obtained by wavelength multiplexing optical signals of wavelengths λ _{1 to} λ N corresponding to channels 1 to _N , respectively. It is assumed that the wavelength of the optical signal to be branched is fixedly assigned in advance at each node. The N-wavelength demultiplexer 1 separates the optical signals λ _{a to} λ _d having the wavelength corresponding to the determined channel and sends them to a terminal or a subscriber (not shown). Send to 2.

The wavelength converter 3 converts the wavelength of an optical signal input to be inserted at this node from a terminal or a subscriber (not shown) based on the control from the control unit 4, and converts the wavelengths λ _I to λ corresponding to the respective channels. Generates an _IV optical signal.

N wavelength multiplexer 2 and the optical signal having a wavelength corresponding to each channel sent from the N wavelength demultiplexer 1, by multiplexing the optical signals of wavelength lambda _I to [lambda] _IV from wavelength converter 3 , Resulting in a wavelength multiplexed optical signal output.

Control unit 4 controls the wavelength converter 3 by the control information extracted from the optical signal of the common wavelength lambda _c that is separated from the optical signal input at N wavelength demultiplexer 1, thereby, in the wavelength converter 3 converting an input optical signal to be inserted in a predetermined wavelength lambda _I to [lambda] _IV. This control can be performed at a low speed. Optical signal common wavelength lambda _c is a signal of a common wavelength for each node sent sequentially to each node is wavelength multiplexed with the optical signal of each channel, is used for controlling the wavelength conversion in each node.

As described above, in the optical add / drop multiplexer of the present invention, since the optical signal of each channel is added and dropped by combining the optical signal with a different wavelength, the demultiplexing and the multiplexing, processing such as bit synchronization and frame synchronization is unnecessary. Yes, the device configuration is simplified.

At this time, the data rate of the optical signal of each channel subjected to wavelength multiplexing may be low (that is, the rate required by the terminal or the subscriber).

〔The invention's effect〕

As described above, in the optical add / drop multiplexer of the present invention, since the processing of dropping and adding is performed with the wavelength-multiplexed optical signal as it is, the device configuration is simplified, and the speed and size of the device can be increased. become.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing the principle configuration of an optical add / drop multiplexer of the present invention, FIG. 2 is a schematic block diagram of an optical add / drop multiplexer as one embodiment of the present invention, and FIG. FIG. 2 is a schematic block configuration diagram of a conventional optical communication system, particularly a schematic block configuration diagram of an optical add / drop multiplexer. DESCRIPTION OF SYMBOLS 1 ... N wavelength splitter 2 ... N wavelength combiner 3 ... Wavelength converter 4 ... Control part 11 ... Optoelectric conversion part (O / E) 12 ... Demultiplexing part 13 ... Branch part 14 control unit 15 electro-optical conversion unit (E / Os) 16 insertion unit 17 photoelectric conversion unit (O / Es) 18 multiplexing unit 19 electro-optical conversion unit (E / O) ) 101 ...... dividing means 102 ...... multiplexing means 103 ...... wavelength converting means C ...... control signal D ...... data signal _{CH I ~CH IV, CH a ~CH} d ...... optical signal

Claims (1)

(57) [Claims] 1. An optical add / drop multiplexer for dropping / adding a wavelength-multiplexed optical signal, comprising: a light having a wavelength including control information in the wavelength-multiplexed optical signal and a light having a wavelength to be output to a terminal or a subscriber. And a wavelength demultiplexer that branches into light of other wavelengths; a control unit that inputs light including control information from the wavelength demultiplexer and extracts a control signal; and the terminal based on the control information from the control unit. Or a wavelength converter for converting the wavelength of light from the subscriber, and a multiplexer for multiplexing the output of the wavelength converter and the light of the other wavelength from the wavelength demultiplexer. Optical add / drop device.