Determination device and determination method

Patent metadata

Field	Value
Publication number	US-9509435-B2
Application number	US-201314100140-A
Country	US
Kind code	B2
Filing date	Dec 9, 2013
Priority date	Jan 17, 2013
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A determination device for a wavelength division multiplex communication system, configured to set each of different paths each of which is formed by connection of spans each of which is a zone between two adjacent transmission devices, among transmission devices forming a communication network, in the communication network, or a single span in the communication network, for the corresponding one of different wavelengths, and configured to transmit an optical signal of each of the wavelengths via the corresponding path set to the wavelength, the device includes: a determination section configured to determine whether an optical signal of at least one of the wavelengths is transmittable only to a path, among newly formed paths, for which the number of spans forming the path is equal to or less than a predetermined upper-limit number, in order to transmit one or more optical signals of one or more wavelengths among the wavelengths.

First claim

What is claimed is:

1. A determination device for a wavelength division multiplex communication system that includes a plurality of transmission devices, each set of adjacent transmission devices being connected by a span, the transmission devices being configured to transmit optical signals of a plurality of wavelengths, each of the optical signals being transmitted via one of a plurality of paths, each of the paths being formed by one or more of the spans, the determination device comprising:
a processor configured to:
when an optical signal of a wavelength among the plurality of wavelengths is to be switched from a currently used path to a new path, determine spare paths that can be used as the new path, each of the spare paths including at least one newly used span that is not included in the currently used path,
for each of the spare paths, determine whether a total number of spans, including the at least one newly used span, forming the spare path is equal to or less than a predetermined upper-limit number of spans,
when the total number of spans forming the spare path is not equal to or less than the predetermined upper-limit number of spans, perform no further processing for that path, and
when the total number of spans forming the spare path is equal to or less than the predetermined upper-limit number of spans, determine whether an optical signal of at least one wavelength among the plurality of wavelengths is transmittable through the spare path.

2. The determination device according to claim 1 , wherein the processor is further configured to use, as the upper-limit number of spans, a value determined in advance in accordance with a modulation method set in advance for a usable wavelength in the target path.

3. The determination device according to claim 1 , wherein the processor is further configured to use, as the upper-limit number of spans, a value determined in advance in accordance with a minimum value of a guard band for spans forming the target path.

4. The determination device according to claim 1 , wherein the processor is further configured to use, as the upper-limit number of spans, a minimum value of a value determined in advance in accordance with a type of an optical fiber for spans forming the target path.

5. The determination device according to claim 1 , wherein the processor is further configured to:
detect an occurrence of a failure in each span,
switch, when the occurrence of the failure is detected, a path formed by the span in which the failure has occurred to a path which bypasses the span in which the failure has occurred, and
perform the determination immediately after the switching of the path is completed.

6. The determination device according to claim 1 , wherein the processor is further configured to:
inform, when it is determined that none of the optical signals of the plurality of wavelengths is newly transmittable to at least one path, the determination result.

7. The determination device according to claim 1 , wherein the processor forms at least a section of one of the transmission devices.

8. A determination method for use in controlling an optical wavelength division multiplex communication system that includes a plurality of transmission devices, each set of adjacent transmission devices being connected by a span, and the transmission devices being configured to transmit optical signals of a plurality of wavelengths, each of the optical signals being transmitted via one of a plurality of paths, each of the paths being formed by one or more of the spans, the method comprising:
determining, when an optical signal of a wavelength among the plurality of wavelengths is to be switched from a currently used path to a new path, spare paths that can be used as the new path, each of the spare paths including at least one newly used span that is not included in the currently used path,
for each of the spare paths, determining whether a total number of spans, including the at least one newly used span, forming the spare path is equal to or less than a predetermined upper-limit number of spans,
when the total number of spans forming the spare path is not equal to or less than the predetermined upper-limit number of spans, performing no further processing for that path, and
when the total number of spans forming the spare path is equal to or less than the predetermined upper-limit number of spans, determining whether an optical signal of at least one wavelength among the plurality of wavelengths is transmittable through the spare path.

Assignees

• Fujitsu Ltd

Inventors

• Shinohara Haruka
• Noheji Kiyotoshi
• Miyashita Takuya

Classifications

• H04B10/038

  using bypasses · CPC title

• H04J14/0257

  Wavelength assignment algorithms · CPC title

• H04J14/0267

  Optical signaling or routing · CPC title

• H04J14/0268 Primary

  Restoration of optical paths, e.g. p-cycles · CPC title

• H04Q2011/0081

  Fault tolerance; Redundancy; Recovery; Reconfigurability · CPC title