Wavelength multiplexing apparatus and method

Patent metadata

Field	Value
Publication number	US-9407396-B2
Application number	US-201414323356-A
Country	US
Kind code	B2
Filing date	Jul 3, 2014
Priority date	Jul 11, 2013
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A wavelength multiplexing apparatus includes: a dividing unit to divide a multiplexed optical signal into a plurality of groups each including a plurality of channels; a designating unit to designate, for each group, an arbitrary channel as a designated channel and to designate an adjacent channel in a predetermined frequency direction; an acquisition unit to acquire a first optical level at a central wavelength in the designated channel and a second optical level at a wavelength at which the designated channel and the adjacent channel interfere with each other; a comparison unit to compare a determined ratio of the second optical level to the first optical level with a reference ratio of a third optical level to the first optical level; and an adjustment unit to adjust a wavelength spacing between the designated channel and the adjacent channel in the group, based on a result of the comparison.

First claim

What is claimed is:

1. A wavelength multiplexing apparatus, comprising:
a dividing unit configured to divide a multiplexed optical signal, in which optical signals of channels in different wavelength bands are multiplexed, into a plurality of groups each including a plurality of channels;
a designating unit configured to designate, for each group, an arbitrary channel of the channels in the group as a designated channel and to designate an adjacent channel that is adjacent to the designated channel in a predetermined frequency direction;
an acquisition unit configured to acquire a first optical power level at a central wavelength in the designated channel and a second optical power level at a wavelength at which the designated channel and the adjacent channel interfere with each other; a comparison unit configured to compare a determined ratio of the second optical power level to the first optical power level with a reference ratio of a third optical power level to the first optical power level; and
an adjustment unit configured to adjust a wavelength spacing between the designated channel and the adjacent channel in the group, based on a result of the comparison.

2. The wavelength multiplexing apparatus according to claim 1 , wherein the third optical power level is an optical level at a wavelength at which adjacent channels in the group interfere with each other and is to be guaranteed in a communication environment of the wavelength multiplexing apparatus.

3. The wavelength multiplexing apparatus according to claim 2 ,
wherein the adjustment unit shifts a central wavelength in the adjacent channel so that the determined ratio and the reference ratio become equal to each other.

4. The wavelength multiplexing apparatus according to claim 3 ,
wherein, when the determined ratio is smaller than the reference ratio, the adjustment unit shifts the central wavelength in the adjacent channel in the predetermined frequency direction; and
when the determined ratio is larger than the reference ratio, the adjustment unit shifts and adjusts the central wavelength in the adjacent channel in a direction opposite to the predetermined frequency direction.

5. The wavelength multiplexing apparatus according to claim 2 ,
wherein, in order that the determined ratio and the reference ratio become equal to each other, the adjustment unit adjusts a filter frequency in a filter band from which a frequency corresponding to a central wavelength in the adjacent channel is to be extracted.

6. The wavelength multiplexing apparatus according to claim 5 ,
wherein, when the determined ratio is smaller than the reference ratio, the adjustment unit shifts the filter frequency in the predetermined frequency direction; and
when the determined ratio is larger than the reference ratio, the adjustment unit shifts the filter frequency in a direction opposite to the predetermined frequency direction.

7. The wavelength multiplexing apparatus according to claim 3 ,
wherein, when the determined ratio in the group becomes equal to the reference ratio, the designating unit designates, in the group, the adjacent channel as a designated channel until a second channel from an end in the group is designated as the adjacent channel and designates, as an adjacent channel, a channel that is adjacent to the designated channel in the predetermined frequency direction.

8. The wavelength multiplexing apparatus according to claim 5 ,
wherein, when the determined ratio in the group becomes equal to the reference ratio, the designating unit designates, in the group, the adjacent channel as a designated channel until a second channel from an end in the group is designated as the adjacent channel and designates, as an adjacent channel, a channel that is adjacent to the designated channel in the predetermined frequency direction.

9. The wavelength multiplexing apparatus according to claim 1 ,
wherein the multiplexed optical signal is transmitted from another wavelength multiplexing apparatus, and the adjustment unit notifies the another wavelength multiplexing apparatus so as to adjust the wavelength spacing between the designated channel and the adjacent channel in the same group in a multiplexed optical signal to be transmitted.

10. The wavelength multiplexing apparatus according to claim 1 ,
wherein, of the channels in the group, a last channel located at a last end in the predetermined frequency direction is set as a signal-less channel.

11. The wavelength multiplexing apparatus according to claim 1 ,
wherein the predetermined frequency direction is a direction in which a frequency in the channels increases.

12. The wavelength multiplexing apparatus according to claim 1 ,
wherein the predetermined frequency direction is a direction in which a frequency in the channels decreases.

13. A wavelength multiplexing method for a wavelength multiplexing apparatus that receives a multiplexed optical signal in which optical signals of channels in different wavelength bands are multiplexed, the wavelength multiplexing method comprising:
dividing the multiplexed optical signal into a plurality of groups each including a plurality of channels;
designating, for each group, an arbitrary channel of the channels in the group as a designated channel and designating an adjacent channel that is adjacent to the designated channel in a predetermined frequency direction;
acquiring a first optical power level at a central wavelength in the designated channel and a second optical power level at a wavelength at which the designated channel and the adjacent channel interfere with each other;
comparing a determined ratio of the second optical power level to the first optical power level with a reference ratio of a third optical power level to the first optical power level; and adjusting a wavelength spacing between the designated channel and the adjacent channel in the group, based on a result of the comparison.

14. A non-transitory computer-readable recording medium storing a program that causes a computer to execute a procedure, the procedure comprising:
dividing a multiplexed optical signal into a plurality of groups each including a plurality of channels, the multiplexed optical signal in which optical signals of channels in different wavelength bands are multiplexed, being received;
designating, for each group, an arbitrary channel of the channels in the group as a designated channel and designating an adjacent channel that is adjacent to the designated channel in a predetermined frequency direction;
acquiring a first optical power level at a central wavelength in the designated channel and a second optical power level at a wavelength at which the designated channel and the adjacent channel interfere with each other;
comparing a determined ratio of the second optical power level to the first optical power level with a reference ratio of a third optical power level to the first optical power level; and adjusting a wavelength spacing between the designated channel and the adjacent channel in the group, based on a result of the comparison.

Assignees

• Fujitsu Ltd

Inventors

• Ishikawa Eiji

Classifications

• H04B10/07957

  Monitoring or measuring wavelength · CPC title

• H04J14/0257 Primary

  Wavelength assignment algorithms · CPC title

• H04J14/0224 Primary

  Irregular wavelength spacing, e.g. to accommodate interference to all wavelengths · CPC title

• H04J14/0227

  Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation · CPC title

• H04J14/0221

  Power control, e.g. to keep the total optical power constant · CPC title