Optical branch insertion device and optical branch insertion method

Patent metadata

Field	Value
Publication number	US-11722235-B2
Application number	US-202017435269-A
Country	US
Kind code	B2
Filing date	Mar 9, 2020
Priority date	Mar 20, 2019
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

The present invention is to provide an optical add/drop multiplexing device capable of realizing a configuration in which many transponders can be connected at low cost.An optical add/drop multiplexing device 30A includes branch function units 34a to 34d connected to each of WSSs 22a to 22d connected to respective routes 1 to D having a plurality of optical fibers and dropping optical signals having a plurality of wavelengths among the optical signals having the respective wavelengths transmitted by wavelength division multiplexing. The optical add/drop multiplexing device includes C-function units 35a to 35d configured to transmit the optical signals branched by the branch function units 34a to 34d to a plurality of transponders. The optical add/drop multiplexing device includes optical couplers 36a to 36d each connected between a set of K WSSs 22c and 22d each having 1 input and M outputs and one of the branch function units 34a, K being a number of 2 or more, the number of optical couplers being equal to or greater than a positive integer obtained by dividing a numerical value D(M−D) by K, the numerical value being obtained by multiplying the number (M−D) of optical signals dropped by each of the WSSs 22c and 22d by the number D of all of the WSSs 22a to 22d. The optical coupler 36a couples optical signals of different wavelengths dropped by a set of WSSs into one optical signal and outputs the coupled optical signal to the branch function unit 34a.

First claim

The invention claimed is:

1. An optical add/drop multiplexing device comprising:
branch function units, including one or more processors, connected to each of WSSs (Wavelength Selective Switches) connected to respective routes, each route i) having a plurality of optical fibers and ii) dropping a subset of optical signals having different wavelengths included in original optical signals having a plurality of wavelengths and being transmitted through the optical fibers by wavelength division multiplexing, wherein the dropped subset of optical signals includes M-D signals, where M is the number of output ports of each WSS, and D is the number of optical paths between the input WSS and the output WSS, wherein an output port for drop is additionally installed for each of the WSSs resulting in that each WSS has a total of M+1 output ports;
CD/CDC (Colorless and Directionless/Colorless, Directionless and Contentionless) function units, including one or more processors, configured to transmit the dropped subset of optical signals that is branched by the branch function units to a plurality of transponders;
a bypass unit, including one or more processors, is configured to be connected between the output port additionally installed and input ports of the CD/CDC function unit and transmit the optical signal by each of the WSSs to the CD/CDC function unit; and
optical couplers each connected between i) a set of K WSSs each having 1 input port and M output ports, K being a number of 2 or more indicating the number of input ports of each optical coupler, and ii) one of the branch function units, the number of optical couplers being equal to or greater than a positive integer obtained by dividing a numerical value D(M-D) by K, the numerical value D(M-D) being obtained by multiplying the number (M-D) of optical signals dropped by each of the WSSs by the number D, wherein
the optical coupler is configured to couple the subset of optical signals of different wavelengths dropped by the set of WSSs connected to the optical coupler into one coupled optical signal and output the one coupled optical signal to the branch function unit.

2. An optical add/drop multiplexing device comprising:
branch function units, including one or more processors, connected to each of WSSs connected to respective routes, each route i) having a plurality of optical fibers and ii) dropping a subset of optical signals having different wavelengths included in original optical signals having a plurality of wavelengths and being transmitted through the optical fibers by wavelength division multiplexing, wherein the dropped subset of optical signals includes M-D signals, where M is the number of output ports of each WSS, and D is the number of optical paths between the input WSS and the output WSS, wherein an output port for drop is additionally installed for each of the WSSs resulting in that each WSS has a total of M+1 output ports;
CD/CDC function units, including one or more processors, configured to transmit the dropped subset of optical signals that is branched by the branch function units to a plurality of transponders;
a bypass unit, including one or more processors, is configured to be connected between the output port additionally installed and input ports of the CD/CDC function unit and transmit the optical signal by each of the WSSs to the CD/CDC function unit; and
selectors each connected between i) a set of K WSSs each having 1 input port and M output ports, K being a number of 2 or more indicating the number of input ports of each selector, and ii) one of the branch function units, the number of selectors being equal to or greater than a positive integer obtained by dividing a numerical value D(M-D) by K, the numerical value D(M-D) being obtained by multiplying the number (M-D) of optical signals dropped by each of the WSSs by the number D, wherein
the selector is configured to select any one of the optical signals dropped by the set of WSSs and output the selected optical signal to the branch function unit, and when one selector of the selectors selects a first optical signal dropped by one of the set of WSSs, the other selector selects a second optical signal dropped by another WSS.

3. An optical add/drop multiplexing method of an optical add/drop multiplexing device including:
branch function units connected to each of WSSs connected to respective routes, each route i) having a plurality of optical fibers and ii) dropping a subset of optical signals having different wavelengths included in original optical signals having a plurality of wavelengths and being transmitted through the optical fibers by wavelength division multiplexing, wherein the dropped subset of optical signals includes M-D signals, where M is the number of output ports of each WSS, and D is the number of optical paths between the input WSS and the output WSS, wherein an output port for drop is additionally installed for each of the WSSs resulting in that each WSS has a total of M+1 output ports,
CD/CDC function units configured to transmit the dropped subset of optical signals that is branched by the branch function units to a plurality of transponders,
a bypass unit configured to be connected between the output port additionally installed and input ports of the CD/CDC function unit and transmit the optical signal by each of the WSSs to the CD/CDC function unit, and
optical couplers each connected between i) a set of K WSSs each having 1 input port and M output ports, K being a number of 2 or more indicating the number of input ports of each optical coupler, and ii) one of the branch function units, the number of optical couplers being equal to or greater than a positive integer obtained by dividing a numerical value D(M-D) by K, the numerical value D(M-D) being obtained by multiplying the number (M-D) of optical signals dropped by each of the WSSs by the number D,
the optical coupler executing: coupling the subset of optical signals of different wavelengths dropped by the set of WSSs connected to the optical coupler into one coupled optical signal and outputting the coupled one optical signal to the branch function unit.

Assignees

• Nippon Telegraph & Telephone

Inventors

• Kawahara Hiroki
• Seki Takeshi

Classifications

• H04J14/02122 Primary

  Colourless, directionless or contentionless [CDC] arrangements · CPC title

• H04J14/0219 Primary

  Modular or upgradable architectures · CPC title

• H04J14/0212 Primary

  using optical switches or wavelength selective switches [WSS] · CPC title

• H04J3/08

  Intermediate station arrangements, e.g. for branching, for tapping-off · CPC title

• H04B10/27

  Arrangements for networking · CPC title