Dynamic Assignment Of Wavelengths In Agile Photonic Networks

Abstract

In an automatically switched optical network, the wavelengths are assigned to optical path based on their intrinsic physical performance and on the current network operating parameters. The wavelength performance information is organized in binning tables, based primarily on the wavelength reach capabilities. A network topology database provides the distance between the nodes of the network, which is used to determine the length of the optical path. Other network operating parameters needed for wavelength selection are also available in this database. Once a bin corresponding to the path length is identified in the binning table, the wavelength for that path is selected based on length only, or based on the length and one or more additional parameters. The optical path performance is estimated for the selected wavelength, and the search continues if the estimated path performance is not satisfactory. Several available wavelengths are searched and of those, the wavelength that is most used along the optical path in consideration or alternatively network-wide is selected and assigned. This method helps minimize wavelength fragmentation. The binning tables may have various granularities, and may be organized by reach, or by reach, wavelength spacing, the load on the respective optical path, the fiber type, etc.

Description

PRIORITY PATENT APPLICATION[0001]This patent application is a continuation in part of the co-pending U.S. patent application Ser. No. 09 / 909,265, entitled “Wavelength Routing and Switching Mechanism for a Photonic Transport Network”, Smith et al., filed Jul. 19, 2001, assigned to Innovance Networks, docket 1021.RELATED U.S. PATENT APPLICATION[0002]U.S. Patent Application “Wavelengths assignment in an optical WDM network”, (Solheim et al.), Ser. No. Not available yet, filed Dec. 12, 2001 assigned to Innovance Networks, docket 1011.[0003]U.S. Patent Application “Regenerator Placement Mechanism For Wavelength Switched Optical Networks” (Rider et al.), Ser. No. not available yet, filed Mar. 13, 2002 and assigned to Innovance Networks, docket 1045.FIELD OF INVENTION[0004]The invention is directed to an agile photonic network (also known as automatically switched optical network ASON, or as all optical network), and in particular to a system and method for assigning wavelengths to a conne...

AI Technical Summary

Benefits of technology

[0020]Advantageously, the wavelength assignment mechanism according to the invention allows fast, automatic establishment of new connections based on the current network architecture, connectivity and loading and also on conditions in the connection request. Finding an appropriate wavelength-path match is performed in a meaningful way, using searching techniques with various degrees of sophistication. Selection of a wavelength for each optical path is performed with optimal use of current network resources, while ensuring that the quality of the selected trail is adequate for the respective call.

[0021]The wavelength searching and selection techniques according to the invention allow reducing the time-to-bandwidth (TTB). Furthermore, the wavelength searching and selection techniques are designed with a view to reduce network resource utilization, by minimizing wavelengths fragmentation, which lowers the need for regenerators, reduces call blocking, and hence contributes to network service costs reduction, while increasing the quality-of-service.

Problems solved by technology

In this architecture, the advantages of the ULR cannot be fully exploited.

This approach dramatically reduces the node complexity, and consequently the network cost.

Nonetheless, the selection and assignment of the right wavelength for each optical path for the best possible utilization of available wavelengths is a complex problem.

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