Top > Search of International Patents > Optical network

Optical network

Foreign code F170009041
File No. J1020-12WO
Posted date Apr 26, 2017
Country EPO
Application number 15754670
Gazette No. 3113391
Date of filing Feb 12, 2015
Gazette Date Jan 4, 2017
International application number JP2015053872
International publication number WO2015129472
Date of international filing Feb 12, 2015
Date of international publication Sep 3, 2015
Priority data
  • P2014-039190 (Feb 28, 2014) JP
  • 2015JP53872 (Feb 12, 2015) WO
Title Optical network
Abstract Provided is an optical network which makes it possible to increase frequency use efficiency of an optical signal when transmitting wavelength division multiplexed light. One or more optical path cross connection devices (OXC) through which a wavelength division multiplexed light signal travels when being transmitted from a prescribed transmission node to a prescribed receiving node, wherein when an optical channel inputted from an input optical fiber (Fi1-Fin) is routed or switched to one or more output optical fibers (Fo1-FoN), a plurality of optical channels adjacent on a frequency axis which are outputted to the same output optical fiber (FoN) in the input optical fibers (Fi1-Fin) are routed or switched to an output optical fiber by demultiplexing the plurality of optical channels as one bundle without demultiplexing each of the optical channels individually. Thus, it is possible to increase frequency use efficiency of an optical signal when transmitting wavelength division multiplexed light, because the instances of optical channel filtering are reduced and the loss caused by filtering is decreased.
Outline of related art and contending technology BACKGROUND ART
An optical network is known that transmits wavelength division multiplexed (WDM) lights including multiple wavebands each consisting of multiplexed optical channels (wavelength channels) of a predetermined bit rate on the order of GHz to THz for each of multiple wavelengths respectively corresponding to multiple optical (wavelength) channels (wavelength channels or light paths) divided based on wavelength by, for example, 100 GHz in a predetermined communication wavelength band, from a predetermined optical node to a plurality of other optical nodes through respective multiple optical fibers in series or in parallel among optical nodes. In such an optical network, an optical path cross-connect apparatus making up each optical node routes optical channels on the basis of wavelengths making up wavelength division multiplexed optical signals transmitted through optical fibers by using the wavelengths as labels to be routed to desired routes (destinations) directly as optical signals through optical paths on the basis of wavelengths, thereby implementing large-capacity transmission with low power consumption.
Because a traffic amount is predicted to increase at an accelerated rate in the optical network due to the recent deployment of ADSL and FTTH and the deployment of services such as high-definition moving image distribution, it is desired to increase the available numbers of wavelength paths and optical fibers and to further increase the scale of optical path cross-connect apparatuses making up nodes in the optical network.
Scope of claims [claim1]
1. An optical network transmitting a wavelength division multiplexing optical signal from a predetermined transmission node to a predetermined reception node via one or more reconfigurable optical add/drop multiplexer and/or optical path cross-connect apparatuses, wherein
when optical channels or optical super channels made up of successive optical subcarriers input from any of input optical fibers are routed or switched to one or more output optical fibers in at least one of the reconfigurable optical add/drop multiplexer and/or the optical path cross-connect apparatus passed through by a wavelength division multiplexing optical signal transmitted from the predetermined transmission node to the predetermined reception node, a plurality of optical channels or optical super channels adjacent to each other on a frequency axis output to the same output optical fiber in each input optical fiber is collectively demultiplexed without being demultiplexed for respective optical channels or optical super channels and is routed or switched to the output optical fiber.
[claim2]
2. The optical network according to claim 1, wherein
when any one of the optical channels or the optical super channels is routed or switched from the transmission node through a plurality of nodes to the reception node, and a plurality of optical channels or optical super channels adjacent to each other on the frequency axis including an optical channel output to the same output optical fiber in each input optical fiber or dropped at the reception node is collectively demultiplexed without being demultiplexed for respective optical channels or optical super channels and is routed or switched to the output optical fiber, filtering of an optical signal for dropping is permitted only for the optical channel or the optical super channel to be dropped at the reception node, and wherein
routing paths and frequency arrangements of the optical channel or the optical super channel as well as optical channels or optical super channels terminated at path-through nodes located on the way are controlled such that the number of times of filtering by a wavelength division filtering mechanism on one or both sides on the frequency axis of the optical channel or the optical super channel becomes equal to or less than a predetermined value.
[claim3]
3. The optical network according to claim 1 or 2, wherein
a plurality of optical channels or optical super channels in a constant width on the frequency axis is collectively routed from the input optical fibers to the output optical fibers at the path-through node, wherein filtering of an optical signal is permitted for the optical signal terminated at the path-through node, and wherein one or more said constant widths are used in the optical network.
[claim4]
4. The optical network according to claim 3, wherein
arrangements of plurality of frequency bands in said one or more constant widths used in the optical network are kept unique in the optical network.
[claim5]
5. The optical network according to claim 3 or 4, wherein
in the case of static design in which the optical network is designed by giving a traffic demand, a route and a frequency arrangement of an optical channel or an optical super channel in the optical network are searched for and assigned such that the number of drop processes of adjacent optical channels at a predetermined node is minimized or becomes equal to or less than a predetermined value with respect to the optical channel or the optical super channel accommodated in a bundle of optical channels or optical super channels having a constant width on the frequency axis, and wherein
in the case of dynamic design in which an optical channel or an optical super channel is accommodated in the optical network each time a demand occurs, a route or a frequency of a demanded optical channel is searched for and assigned such that the number of drop processes at a node is minimized or becomes equal to or less than a predetermined value with respect to the demanded optical channel or optical super channel as well as existing adjacent optical channels or optical super channels when a route or a frequency is assigned to a newly arriving demand.
[claim6]
6. The optical network according to any one of claims 1 to 5, wherein
a plurality of optical channels or optical super channels is collectively routed as a bundle with a constant width on the frequency axis from input optical fibers to output optical fibers at a path-through node located on the way, and wherein the optical channels or the optical super channels are separately routed or switched in a frequency band in which the bundle is not set.
  • Applicant
  • JAPAN SCIENCE AND TECHNOLOGY AGENCY
  • Inventor
  • SATO Ken-ichi
  • HASEGAWA Hiroshi
  • MORI Yojiro
  • TERADA Yuki
IPC(International Patent Classification)
Specified countries Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Please contact us by E-mail or facsimile if you have any interests on this patent.

PAGE TOP

close
close
close
close
close
close