METHOD FOR OPTIMIZING THE CAPACITY OF OPTICAL COMMUNICATION NETWORKS

• US 20130022355A1
• Filed: 02/24/2011
• Published: 01/24/2013
• Est. Priority Date: 03/18/2010
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Charlet, Gabriel, Bertran-Pardo, Oriol, Vacondio, Francesco
• Granted Patent: US 8,849,118 B2
• Time in Patent Office: Days
• US Class Current: 398/48
• CPC Class Codes: H04J 14/0204 Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping
• CPC Class Codes: H04J 14/0208 Interleaved arrangements
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0213 Groups of channels or wave bands arrangements
• CPC Class Codes: H04J 14/0217 Multi-degree architectures, e.g. having a connection degree greater than two
• CPC Class Codes: H04J 14/0224 Irregular wavelength spacing, e.g. to accommodate interference to all wavelengths
• CPC Class Codes: H04J 14/0257 Wavelength assignment algorithms
• CPC Class Codes: H04J 14/026 using WDM channels of different transmission rates

Abstract

The embodiments of the present invention describe a method for optimizing the capacity of an optical communication network that uses wavelength division multiplexing, wherein the spectral distribution of the signals intended to be transmitted over a plurality of channels is done dynamically through the use of a variable spectrum grid whose spectral spacings between two successive channels are determined based on the spectral width of said signals and in which dynamic filtering of said signals is carried out before their transmission in order to adjust their spectral width based on the available spectral space, and thereby reduce crosstalk between adjacent channels when the signals are transmitted.

Claims

1. A method for optimizing the capacity of an optical communication network that uses wavelength division multiplexing, wherein the spectral distribution of the signals intended to be transmitted over a plurality of channels is done dynamically through the use of a variable spectral grid whose spectral spacings between two successive channels are determined based on the spectral width of said signals and in which dynamic filtering of said signals is carried out before their transmission in order to adjust their spectral width based on the available spectral space, and thereby reduce crosstalk between adjacent channels when the signals are transmitted.

2. An optimization method according to claim 1, wherein the determination of the spectral spacings and the filtering applied to the signals is carried out with consideration for the inter-symbol interferences introduced by said filtering.

3. An optimization method according to claim 1, wherein the determination of both the spectral spacings and the filtering applied to the signals is carried out with consideration for the range desired for said signals.

4. An optimization method according to claim 1, wherein the dynamic filtering of the signals is carried out within a wavelength-selective switch.

5. An optimization method according to claim 4 wherein the signals intended to be transmitted are distributed into at least two groups, said at least two groups being sent to at least two distinct input ports of the wavelength-selective switch in order to be filtered separately.

6. An optimization method according to claim 5 wherein the distribution of the signals within said at least two groups is carried out so as to produce a maximum spectral spacing between two successive channels within said at least two groups.

7. An optimization method according to claim 5 wherein, after filtering, the signals of said at least two groups are wavelength division multiplexed within an optical coupler.

8. An optimization method according to claim 5, wherein a dynamic reception procedure is used in order to select a channel and detect it.

9. An optical signal transmission device comprising means configured to:

determine the optimal spectral spacings between the various channels carrying optical signals intended to be transmitted as a function of the spectral width of said signals and the desired range present signals,

establishing a special grid whose spectral spacings between two successive channels correspond to the previously determined spectral spacings,

filtering said signals in order to adjust their spectral width as a function of the available spectral spacing and thereby to reduce crosstalk between adjacent channels when signals are transmitted.

10. An optical signal transmission device according to claim 9, wherein the means configured to filter said signals comprise a wavelength-selective switch equipped with dynamic filters.

11. An optical signal transmission device according to claim 9 wherein said device also comprises means configured to distribute the signals intended to be transmitted into at least two distinct groups, said two groups being sent to two distinct ports of the wavelength-selective switch so that they can be filtered separately.

12. An optical signal transmission device according to claim 11 wherein said device comprises means configured to multiplex the filtered signals corresponding to said at least two groups of signals.

13. An optical signal transmission device comprising means configured to:

dynamically filter the received signals in order to select the spectral widths corresponding to the transmission channels in order to transmit the signal corresponding to a transmission channel to a receiver in order to enable the detection of said signal.