OPTICAL TRANSMISSION SYSTEM

• US 20110318007A1
• Filed: 01/14/2010
• Published: 12/29/2011
• Est. Priority Date: 03/13/2009
• Status: Abandoned Application

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Oikawa, Shingo
• Application Number:
  US13/255,674
• Publication Number:
  US 20110318007A1
• Time in Patent Office: Days
• US Class Current: 398/50
• CPC Class Codes: H04B 10/0793 Network aspects, e.g. central monitoring of transmission parameters
• CPC Class Codes: H04J 14/0284 WDM mesh architectures
• CPC Class Codes: H04J 14/0294 Dedicated protection at the optical channel (1+1)
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/62 Wavelength based optical switching H04Q11/0062
• CPC Class Codes: H04Q 2213/1301 Optical transmission, optical switches
• CPC Class Codes: H04Q 2213/1302 Relay switches

Abstract

An optical transmission system 100 includes a plurality of transmission devices 110 to 150 each configured to be capable of transmitting and receiving an optical signal at each of a plurality of different wavelengths and thereby transmitting and receiving a plurality of optical signals simultaneously. The transmission device 120 transmits an optical signal received at a transmission wavelength to each of the transmission device 130 and the transmission device 140. The optical transmission system transmits the optical signal at the transmission wavelength from the transmission device 110 to the transmission device 150 via each of a plurality of paths that partly overlap. The optical transmission system estimates, for each of the paths, a line quality representing the degree of coincidence between an optical signal transmitted by the transmission device 110 and an optical signal received by the transmission device 150.

Claims

1. An optical transmission system comprising a plurality of transmission devices, each transmission device being configured to be capable of transmitting and receiving an optical signal at each of a plurality of different wavelengths and thereby transmitting and receiving a plurality of optical signals simultaneously, wherein:

the transmission device is configured to transmit an optical signal received at a certain wavelength, at the wavelength;

the plurality of transmission devices include a transmission source device serving as the transmission device, a transmission destination device serving as the transmission device, a branching source device serving as the transmission device, a first branching destination device serving as the transmission device, and a second branching destination device serving as the transmission device; and

the branching source device is configured to transmit an optical signal received at a predetermined transmission wavelength to each of the first branching destination device and the second branching destination device,

the optical transmission system comprising;

an optical signal transmission unit configured to transmit an optical signal at the transmission wavelength from the transmission source device to the transmission destination device via each of a plurality of paths including a first path and a second path, the first path being formed by an overlapping part connecting the transmission source device to the branching source device and a first branching part connecting the branching source device to the transmission destination device via the first branching destination device, and the second path being formed by the overlapping part and a second branching part connecting the branching source device to the transmission destination device via the second branching destination device; and

a line quality estimation unit configured to estimate, for each of the paths, a line quality representing a degree of coincidence between an optical signal transmitted by the transmission source device and an optical signal received by the transmission destination device.

2. The optical transmission system according to claim 1, comprising:

a path selection unit configured to select one path from among the plurality of paths based on the estimated line quality, wherein;

the transmission destination device is configured to use an optical signal transmitted via the selected path, as an optical signal received from the transmission source device.

3. The optical transmission system according to claim 2, wherein:

the branching source device includes a branching unit configured to branch the received optical signal and thereby output a plurality of optical signals that are the same as the received optical signal, and is configured to transmit one of the plurality of optical signals having been outputted to the first branching destination device and transmit another one of the plurality of optical signals having been outputted to the second branching destination device.

4. The optical transmission system according to claim 3, wherein:

the branching source device includes a connection switching unit that has a plurality of ports including a first port into which one of the plurality of optical signals outputted by the branching unit is inputted, a second port into which another one of the plurality of optical signals outputted by the branching unit, a third port connected with the first branching destination device and a fourth port connected with the second branching destination device, and that is configured to be capable of connecting any two ports among the plurality of ports.

5. The optical transmission system according to claim 4, wherein:

the connection switching unit is a cross-connect device.

6. An optical transmission method applied to an optical transmission system comprising a plurality of transmission devices, each transmission device being configured to be capable of transmitting and receiving an optical signal at each of a plurality of different wavelengths and thereby transmitting and receiving a plurality of optical signals simultaneously, wherein:

the transmission device is configured to transmit an optical signal received at a certain wavelength, at the wavelength; and

the plurality of transmission devices include a transmission source device serving as the transmission device, a transmission destination device serving as the transmission device, a branching source device serving as the transmission device, a first branching destination device serving as the transmission device, and a second branching destination device serving as the transmission device,

the optical transmission method comprising;

by transmission of an optical signal received at a predetermined transmission wavelength to each of the first branching destination device and the second branching destination device by the branching source device, transmitting an optical signal at the transmission wavelength from the transmission source device to the transmission destination device via each of a plurality of paths including a first path and a second path, the first path being formed by an overlapping part connecting the transmission source device to the branching source device and a first branching part connecting the branching source device to the transmission destination device via the first branching destination device, and the second path being formed by the overlapping part and a second branching part connecting the branching source device to the transmission destination device via the second branching destination device; and

estimating, for each of the paths, a line quality representing a degree of coincidence between an optical signal transmitted by the transmission source device and an optical signal received by the transmission destination device.

7. The optical transmission method according to claim 6, comprising:

selecting one path from among the plurality of paths based on the estimated line quality; and

using an optical signal transmitted via the selected path, as an optical signal received from the transmission source device by the transmission destination device.

8. The optical transmission method according to claim 7, comprising:

by branching the received optical signal by the branching source device, generating a plurality of optical signals that are the same as the received optical signal; and

transmitting one of the plurality of optical signals having been generated to the first branching destination device and transmitting another one of the plurality of optical signals having been generated to the second branching destination device.

9. A transmission device:

configured to be capable of transmitting and receiving an optical signal at each of a plurality of different wavelengths and thereby transmitting and receiving a plurality of optical signals simultaneously, and configured to transmit an optical signal received at a certain wavelength, at the wavelength; and

configured to transmit an optical signal received at a predetermined transmission wavelength to each of a first branching destination device and a second branching destination device.

10. The transmission device according to claim 9:

including a branching unit configured to branch the received optical signal and thereby output a plurality of optical signals that are the same as the received optical signal, and being configured to transmit one of the plurality of optical signals having been outputted to the first branching destination device and transmit another one of the plurality of optical signals having been outputted to the second branching destination device.

11-12. -12. (canceled)