JP2014143518A - Transmitter and transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique which allows for adjustment of the intensity of an optical signal having a predetermined wavelength, even in a state where optical signals of a plurality of wavelengths are superposed.SOLUTION: A measurement section measures the intensity of optical signals of a plurality of wavelengths taken out from a wavelength division multiplexed signal. A transponder receives the optical signals of a plurality of wavelengths thus taken out and outputs the optical signals to the outside, and measures the total intensity of the optical signals of a plurality of wavelengths thus received. Based on the intensity of the optical signals of a plurality of wavelengths measured by the measurement section, and the total intensity of the optical signals of a plurality of wavelengths measured by the transponder, a control section estimates the intensity of one optical signal received by the transponder, and adjusts the intensity of an optical signal of one wavelength thus received.

Description

  The present invention relates to a transmission apparatus and a transmission system.

  2. Description of the Related Art Conventionally, a transmission apparatus extracts a plurality of wavelengths of optical signals from a received wavelength division multiplexing (WDM) signal, separates the extracted plurality of wavelengths of optical signals, and accommodates the plurality of wavelengths. Output to each transponder.

  For example, a technology is known in which a transmission apparatus adjusts the intensity for each optical signal having a separated wavelength and outputs the signal to each transponder (see, for example, Patent Document 1).

JP 2003-198478 A

  However, with the conventional technology, it is difficult to adjust the intensity of an optical signal having a predetermined wavelength in a state where optical signals having a plurality of wavelengths are superimposed.

  In view of the problems of the prior art, it is an object of the present disclosure to provide a technique capable of adjusting the intensity of an optical signal having a predetermined wavelength even when optical signals having a plurality of wavelengths are superimposed.

  One aspect of the transmission device of the present disclosure includes a measuring unit that measures the intensity of an optical signal having a plurality of wavelengths extracted from a wavelength division multiplexed optical signal, and an external device that receives the extracted optical signals having a plurality of wavelengths. At least one transponder that outputs and measures the total intensity of the received optical signals of the plurality of wavelengths, the intensity of the optical signals of the plurality of wavelengths measured by the measuring unit, and the light of the plurality of wavelengths measured by the transponder And a controller that estimates the intensity of the optical signal of one wavelength received by the transponder based on the total intensity of the signal and adjusts the intensity of the optical signal of one wavelength received.

  One aspect of the transmission system according to the present disclosure includes a plurality of transmission apparatuses, and each transmission apparatus includes a measurement unit that measures the intensity of an optical signal having a plurality of wavelengths extracted from the wavelength-division multiplexed optical signal, and an extraction unit. Receiving at least one optical signal of a plurality of wavelengths and outputting the same to the outside, at least one transponder for measuring the total intensity of the received optical signals of the plurality of wavelengths, and the intensity of the optical signals of the plurality of wavelengths measured by the measuring unit And the intensity of the optical signal of one wavelength received by the transponder based on the total intensity of the optical signals of a plurality of wavelengths measured by the transponder, and adjust the intensity of the optical signal of one wavelength received A control unit.

  The transmission device and the transmission system of the present disclosure can adjust the intensity of an optical signal having a predetermined wavelength even in a state where optical signals having a plurality of wavelengths are superimposed.

It is a figure which shows one Embodiment of a transmission system and a transmission apparatus. It is a figure which shows the example of the relay apparatus shown in FIG. 3 is a flowchart showing an operation of adjusting the intensity of an optical signal by the repeater shown in FIG. It is a figure which shows the other example of the relay apparatus shown in FIG. 6 is a flowchart showing an operation of adjusting the intensity of an optical signal by the relay device shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<< One Embodiment >>
FIG. 1 shows an embodiment of a transmission system and a transmission apparatus according to the present disclosure.

  The transmission system 100 of this embodiment includes terminal devices 1 (1-1 to 1-M), 2 (2-1 to 2-M), WDM devices 3a and 3b, and relay devices 10 (10-1 to 10-1) such as computers. 10-N). M and N are positive integers. The WDM device 3a, the relay device 10-1 to the relay device 10-N, and the WDM device 3b are connected to each other via a transmission path 4 (4-1 to 4- (N + 1)) such as an optical fiber. The relay devices 10-1 to 10-N are examples of transmission devices.

The WDM device 3a wavelength-division-multiplexes the optical signals having the wavelengths λ _{1 to} λ _M from each terminal device 1, and outputs the obtained WDM signal to the transmission line 4-1. Also, the WDM device 3a separates the optical signals having wavelengths λ ₁ to λ _M from the WDM signal received via the transmission path 4-1, and outputs the optical signals to each terminal device 1. For example, the WDM signal is an optical signal such as SONET (Synchronous Optical Network) / SDH (Synchronous Digital Hierarchy) standard. Further, since the WDM device 3b performs the same operation as the WDM device 3a, the description of the WDM device 3b is omitted.

  FIG. 2 shows an example of the relay apparatus 10 shown in FIG. The relay apparatus 10-k illustrated in FIG. 2 is a positive integer and 1 ≦ k ≦ N. That is, the relay apparatuses 10-1 to 10-N illustrated in FIG. 1 have the same configuration.

  The relay apparatus 10-k includes a control unit 30, a WSS (Wavelength Selective Switch) 31, an optical coupler 32, a measurement unit 33, and a plurality of transmission / reception units 34 (34-1 to 34-S) (S is a positive integer). .

  For example, the control unit 30 is a microprocessor that executes a control program stored in a memory 35 such as a ROM (Read Only Memory) and comprehensively controls each unit of the relay device 10-k. The control unit 30 controls relay processing of the WDM signal that is transmitted through the transmission lines 4-k and 4- (k + 1). Further, the control unit 30 adjusts the intensity of the optical signal of the wavelength received by the transponders 42 (42-1 to 42-L) included in each transmission / reception unit 34 as described in FIG. 3 (L is a positive integer). ).

  Under the control of the control unit 30, the WSS 31 extracts optical signals having a plurality of wavelengths set in the respective transmission / reception units 34 from the WDM signals transmitted through the transmission paths 4-k, 4- (k + 1), and transmits / receives each transmission / reception unit. 34. The WSS 31 also outputs the optical signal output to each transmission / reception unit 34 to the optical coupler 32. The WSS 31 is an example of an extraction unit.

  The measurement unit 33 receives optical signals having a plurality of wavelengths extracted by the transmission / reception units 34 via the optical coupler 32. The measurement part 33 measures the intensity | strength of the received optical signal of each wavelength. For example, the measurement unit 33 uses a local light source that is a built-in variable wavelength laser light source, and causes the local light source to emit laser light of each wavelength based on the control of the control unit 30. The measurement unit 33 causes the laser light of the local light source to interfere with the received optical signals having a plurality of wavelengths, and measures the intensity of the optical signal having each wavelength. Or the measurement part 33 may measure the intensity | strength of the received optical signal of each wavelength using the wavelength-variable bandpass filter built in.

  The transmission / reception units 34-1 to 34-S include an optical amplifier 40, an optical coupler 41, and a transponder 42-1 to a transponder 42-L. FIG. 2 shows elements of the transmission / reception unit 34-1. The transmission / reception units 34-2 to 34-S also have the same configuration as that of the transmission / reception unit 34-1.

  Note that each of the transmission / reception units 34-1 to 34-S includes L transponders 42, but is not limited thereto. For example, each transmission / reception unit 34 may have a different number of transponders 42. One transmission / reception unit 34 having one transponder 42 may be arranged.

  Each transmission / reception unit 34 receives optical signals of a plurality of wavelengths from the WSS 31 according to the number of transponders 42 to be accommodated. That is, the WSS 31 extracts an L × S wavelength optical signal from the WDM signal, and outputs an L wavelength optical signal to each transmission / reception unit 34.

  The optical amplifier 40 amplifies the optical signals of L wavelengths received by each transmission / reception unit 34.

  The optical coupler 41 distributes optical signals of L wavelengths received and amplified by the respective transmission / reception units 34 to the transponders 42-1 to 42-L. In place of the optical coupler 41, a WSS similar to the WSS 31 may be arranged. However, the optical coupler 41 is preferably used because it is less expensive than WSS.

  Each transponder 42-1 to transponder 42-L receives the optical signal of L wavelengths distributed by the optical coupler 41, and selects an optical signal of one preset wavelength from the received L optical signals. This is a multi-channel receiving transponder. For example, each transponder 42 uses a local light source that is a built-in variable wavelength laser light source, emits a laser beam having a wavelength set in the local light source, and interferes with an optical signal having L wavelengths. An optical signal having a single wavelength is selected. Each transponder 42 extracts data from the optical signal of the selected wavelength, and outputs the extracted data to each terminal device 50 (50-1 to 50-S) such as a computer. Each transponder 42 includes a photodiode that measures the total intensity of the total of the intensities of optical signals having L wavelengths.

  FIG. 3 shows an operation of adjusting the intensity of the optical signal by the repeater 10-k shown in FIG.

  Step S101: Based on the control of the control unit 30, the WSS 31 extracts, from the WDM signal, optical signals of L wavelengths respectively set in the transponders 42-1 to 42-L of each transmission / reception unit 34. The WSS 31 outputs the extracted optical signals of L wavelengths to each transmission / reception unit 34. At the same time, the WSS 31 also outputs optical signals of L wavelengths extracted for each transmission / reception unit 34 to the measurement unit 33 via the optical coupler 32.

Step S102: The measurement unit 33 sequentially receives optical signals of L wavelengths output for each transmission / reception unit 34. The measuring unit 33 measures the intensity PW (λ _i (j)) of the optical signal having L × S wavelengths λ _i (j). Here, λ _i (j) represents the wavelength of the received optical signal set in the transponder 42-i of the transmission / reception unit 34-j. Further, i is a positive integer of 1 to L, and j is a positive integer of 1 to S.

In addition, the measurement unit 33 uses, for example, the expression (1) to measure the total intensity APW (j) of the optical signals of L wavelengths output to each transmission / reception unit 34, and measure the intensity PW (λ _i (j )). Here, the total intensity APW (j) is the total intensity of the optical signals of L wavelengths output to the transmission / reception unit 34-j.

  Step S103: The transponders 42-1 to 42-L of each transmission / reception unit 34 measure the total intensity TPW (j, i) of the received optical signals of L wavelengths using a photodiode or the like. Here, the total intensity TPW (j, i) indicates the total intensity of signals of L wavelengths measured by the transponder 42-i of the transmission / reception unit 34-j.

Step S104: Based on the obtained intensity PW (λ _i (j)), total intensity APW (j), and total intensity TPW (j, i), the control unit 30 applies each transponder 42 included in each transmission / reception unit 34 to each transponder 42. The intensity of the optical signal having the set wavelength λ _i (j) is estimated. For example, the control unit 30 uses Equation (2) to estimate the intensity E (λ _i (j)) of the optical signal having the wavelength λ _i (j) in the transponder 42-i included in the transmission / reception unit 34-j. Is calculated.

Step S105: The control unit 30 determines that the estimated value E (λ _i (j)) estimated in Step S104 is an optical signal intensity allowable value β set in advance in the transponder 42-i included in the transmission / reception unit 34-j. It is determined whether or not (j, i) or less. When the estimated value E (λ _i (j)) is equal to or smaller than the allowable value β (j, i), the control unit 30 proceeds to step S107 (YES side). On the other hand, when the estimated value E (λ _i (j)) is larger than the allowable value β (j, i), the control unit 30 proceeds to step S106 (NO side). The allowable value β (j, i) is preferably set according to the performance of the transponder 42 and is preferably stored in the memory 35 in advance.

Step S106: When the estimated value E (λ _i (j)) is larger than the allowable value β, the control unit 30 adjusts the angle of the mirror of the WSS 31 with respect to the WSS 31 to thereby adjust the wavelength λ _i (j) to be extracted. Reduce the intensity of the optical signal. Here, the mirror is a MEMS (Micro Electro Mechanical System) mirror or the like, and is provided in the WSS 31 in order to extract an optical signal having a plurality of wavelengths from the WDM signal and output it to a port determined for each wavelength according to the mirror angle. . Control part 30 transfers to Step S101 and performs processing of Step S101-Step S105.

Step S107: The control unit 30 calculates a difference between the estimated value E (λ _i (j)) estimated in step S104 and the intensity PW (λ _i (j)), and whether the calculated difference is equal to or greater than a predetermined threshold value. Determine whether. When the calculated difference is equal to or greater than the predetermined threshold, the control unit 30 proceeds to step S108 (YES side). On the other hand, when the calculated difference is smaller than the predetermined threshold (NO side), the control unit 30 operates normally in the transponder 42-i of the transmission / reception unit 34-j in which the estimated value E (λ _i (j)) is estimated. It is determined that it is in progress, and the series of operations is terminated.

Step S108: The control unit 30 determines that an abnormality has occurred in the transponder 42-i of the transmission / reception unit 34-j whose estimated value E (λ _i (j)) has been estimated. The control unit 30 outputs information that warns an administrator who manages the transmission system 100. In addition, it is preferable that the control part 30 outputs the information of the transponder 42-i of the transmission / reception unit 34-j where the abnormality has occurred together with the alarm of the occurrence of the abnormality. Based on the information, the administrator can quickly recover the transponder 42-i of the transmission / reception unit 34-j in which an abnormality has occurred. The control unit 30 ends a series of operations.

  In addition, it is preferable that the control part 30 repeats the process of step S101-step S108 with a predetermined time interval.

  In the present embodiment, the measurement unit 33 and each transponder 42 independently measure the intensity of optical signals having a plurality of wavelengths. Thereby, the control part 30 can estimate the intensity | strength of the optical signal of the predetermined wavelength which each transponder 42 receives from those measurement results, and can adjust the intensity | strength of the optical signal of the predetermined wavelength to receive.

Further, the control unit 30 can determine whether or not each transponder 42 is operating normally based on a comparison between the estimated value E (λ _i (j)) and a predetermined threshold value. The quality of the optical signal can be improved as compared with the prior art.

In the present embodiment, an example in which the transmission system 100 includes the relay device 10 as an example of a transmission device has been described, but the present invention is not limited to this. For example, when the WDM devices 3a and 3b include a transponder 42 having a multi-channel reception function, the WDM devices 3a and 3b may operate as a transmission device of the present disclosure.
<< Other embodiments >>
Other embodiments of the transmission system and the transmission apparatus of the present disclosure are the same as the transmission system 100 illustrated in FIG. Therefore, detailed description of the same elements as those in FIG. 1 is omitted.

FIG. 4 shows another example of the relay device 10 shown in FIG. 4 having the same functions as those of the relay device 10-k shown in FIG. 2 are assigned the same reference numerals and detailed descriptions thereof are omitted. In the relay apparatus 10-k illustrated in FIG. 4, an optical amplifier 60 is disposed instead of the optical amplifier 40 in each transmission / reception unit 34 of the relay apparatus 10-k illustrated in FIG. 2. The optical amplifier 60 has a wavelength dependency in which the amplification factor of the optical signal changes according to the wavelength. In the memory 35, the wavelength dependency data of the amplification factor measured when the optical amplifier 60 of each transmission / reception unit 34 is manufactured. Are stored together with the control program. The wavelength dependence data stored in the memory 35 is, for example, the ratio α (λ _i (j)) of the amplification factor of the optical signal having the wavelength λ _i (j) to the amplification factor of the optical signal having the reference wavelength. The optical amplifier 60 is an example of an amplification unit, and the memory 35 is an example of a storage unit.

  FIG. 5 shows an operation of adjusting the intensity of the optical signal by the repeater 10-k shown in FIG. In each step shown in FIG. 5, the same step numbers are assigned to those performing the same process as the step shown in FIG. 3, and detailed description thereof is omitted.

However, in step S <b> 201, the control unit 30 reads the wavelength dependency data of the optical amplifier 60 of each transmission / reception unit 34 stored in the memory 35. Based on the read wavelength dependence data, the control unit 30 causes the WSS 31 to have L wavelengths of the L wavelengths so that the intensities of the L wavelength optical signals amplified by the optical amplifier 60 are equal to each other. The light signal intensity is adjusted and extracted. For example, the control unit 30 includes a mirror included in the WSS 31 so that the intensity of the optical signal having the wavelength λ _i (j) is 1 / α (λ _i (j)) times based on the wavelength dependency data. Are adjusted to extract an optical signal having a wavelength λ _i (j).

  In the present embodiment, the measurement unit 33 and each transponder 42 independently measure the intensity of optical signals having a plurality of wavelengths. Thereby, the control part 30 can estimate the intensity | strength of the optical signal of the predetermined wavelength which each transponder 42 receives from those measurement results, and can adjust the intensity | strength of the optical signal of the predetermined wavelength to receive.

  Further, the control unit 30 causes the WSS 31 to adjust the intensity of the optical signal of each wavelength based on the wavelength dependency data so that the intensity of the optical signal of each wavelength after amplification by the optical amplifier 60 becomes equal. . Thereby, this embodiment can adjust the intensity | strength of the optical signal of a receiving wavelength more correctly than one embodiment.

Furthermore, the control unit 30 can determine whether or not each transponder 42 is operating normally based on a comparison between the estimated value E (λ _i (j)) and a predetermined threshold value. The quality of the optical signal can be improved as compared with the prior art.

  In the present embodiment, an example in which the transmission system 100 includes the relay device 10 as an example of a transmission device has been described, but the present invention is not limited to this. For example, when the WDM devices 3a and 3b include a transponder 42 having a multi-channel reception function, the WDM devices 3a and 3b may operate as a transmission device of the present disclosure.

In FIG. 5, the control unit 30 causes the WSS 31 to adjust the intensity of the optical signal having the wavelength λ _i (j) in steps S <b> 105 to S <b> 106, but is not limited thereto. For example, in step S201 illustrated in FIG. 5, the control unit 30 sets the allowable value β (j, i) in which the intensity of the optical signal of each wavelength is set in each transponder 42 in the WSS 31 based on the wavelength dependence data. ) You may adjust it so that it becomes the following. In that case, it is preferable that Steps S105 to S106 shown in FIG. 5 are omitted.

  From the above detailed description, features and advantages of the embodiments will become apparent. This is intended to cover the features and advantages of the embodiments described above without departing from the spirit and scope of the claims. Also, any improvement and modification should be readily conceivable by those having ordinary knowledge in the art. Therefore, there is no intention to limit the scope of the inventive embodiments to those described above, and appropriate modifications and equivalents included in the scope disclosed in the embodiments can be used.

1-1 to 1-M, 2-1 to 2-M, 50-1 to 50-S... Terminal device; 3a, 3b ... WDM device; 4-1 to 4- (N + 1). -10-N ... repeater; 30 ... control unit; 31 ... WSS; 32 ... optical coupler; 33 ... measuring unit; 34-1 to 34-S ... transmission / reception unit; 35 ... memory; ... Optical coupler; 42-1 to 42-L ... Transponder; 100 ... Transmission system

Claims (8)

A measurement unit for measuring the intensity of optical signals of a plurality of wavelengths extracted from the wavelength-division multiplexed optical signal;
At least one transponder that receives and outputs the extracted optical signals of the plurality of wavelengths to the outside, and measures the total intensity of the received optical signals of the plurality of wavelengths;
An optical signal of one wavelength received by the transponder based on the intensity of the optical signal of the plurality of wavelengths measured by the measuring unit and the total intensity of the optical signal of the plurality of wavelengths measured by the transponder A control unit that estimates the intensity of the optical signal and adjusts the intensity of the optical signal having one wavelength to be received;
A transmission apparatus comprising: The transmission apparatus according to claim 1,
The measurement unit measures the intensity of the optical signal of each wavelength, calculates the total intensity of the optical signals of the plurality of wavelengths,
The control unit is configured to receive light of one wavelength received by the transponder based on the intensity and the total intensity of the optical signal of each wavelength by the measurement unit and the total intensity of the optical signal of the plurality of wavelengths by the transponder. A transmission apparatus characterized by estimating the strength of a signal. The transmission apparatus according to claim 1 or 2,
An extraction unit for extracting the optical signals of the plurality of wavelengths from the wavelength division multiplexed optical signal;
When the estimated intensity of the optical signal of one wavelength to be received is larger than a preset allowable value, the controller reduces the intensity of the optical signal of the one wavelength to be received to the extraction unit. A characteristic transmission device. The transmission apparatus according to claim 1 or 2,
An extraction unit for extracting the optical signals of the plurality of wavelengths from the wavelength-division multiplexed optical signal;
An amplification unit that amplifies the optical signals of the plurality of wavelengths extracted by the extraction unit;
A storage unit for storing data indicating the wavelength dependence of the amplification factor of the amplification unit,
The control unit causes the extraction unit to adjust the intensity of the optical signal of each wavelength based on the data so that the intensity of the optical signal of each wavelength amplified by the amplification unit becomes equal to each other. A characteristic transmission device. A plurality of transmission devices,
Each of the transmission devices is
A measurement unit for measuring the intensity of optical signals of a plurality of wavelengths extracted from the wavelength-division multiplexed optical signal;
At least one transponder that receives and outputs the extracted optical signals of the plurality of wavelengths to the outside, and measures the total intensity of the received optical signals of the plurality of wavelengths;
An optical signal of one wavelength received by the transponder based on the intensity of the optical signal of the plurality of wavelengths measured by the measuring unit and the total intensity of the optical signal of the plurality of wavelengths measured by the transponder And a control unit that adjusts the intensity of the optical signal having one wavelength to be received. The transmission system according to claim 5, wherein
The measurement unit measures the intensity of the optical signal of each wavelength, calculates the total intensity of the optical signals of the plurality of wavelengths,
The control unit is configured to receive light of one wavelength received by the transponder based on the intensity and the total intensity of the optical signal of each wavelength by the measurement unit and the total intensity of the optical signal of the plurality of wavelengths by the transponder. A transmission system characterized by estimating signal strength. In the transmission system according to claim 5 or 6,
Each of the transmission devices is
An extraction unit for extracting the optical signals of the plurality of wavelengths from the wavelength division multiplexed optical signal;
When the estimated intensity of the optical signal of one wavelength to be received is larger than a preset allowable value, the controller reduces the intensity of the optical signal of the one wavelength to be received to the extraction unit. Characteristic transmission system. In the transmission system according to claim 5 or 6,
Each of the transmission devices is
An extraction unit for extracting the optical signals of the plurality of wavelengths from the wavelength-division multiplexed optical signal;
An amplification unit that amplifies the optical signals of the plurality of wavelengths extracted by the extraction unit;
A storage unit that stores data indicating the wavelength dependence of the amplification factor of the amplification unit;
The control unit causes the extraction unit to adjust the intensity of the optical signal of each wavelength based on the data so that the intensity of the optical signal of each wavelength amplified by the amplification unit becomes equal to each other. Characteristic transmission system.

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