Wavelength switched optical network
Wavelength switched optical network (WSON) is a type of telecommunications network.
A WSON consist of two planes: the data and the control planes. The data plane comprises wavelength-division multiplexing (WDM) fiber links connecting optical cross-connect (OXCs) through a comb of several tens of wavelength channels, with typical data rates of 10 or 40 Gb/s. Optical end-to-end connections (i.e., lightpaths) are established in the optical domain and switched by OXCs at the wavelength granularity.
In WSONs the optical signal is switched at the wavelength granularity, therefore the wavelength assignment process, selecting the carrier of each established lightpath, plays a crucial role in dynamic network operation.
The dynamic provisioning and maintenance of lightpaths is managed by the control plane. The control plane is implemented on a separate network and typically employs one network controller for each node in the data plane, as shown in the figure. The Generalized Multi-Protocol Label Switching (GMPLS) protocol suite, the de facto standard control plane for WSONs proposed by the IETF, is composed of three protocols.
- G. M. Bernstein, Y. Lee, A. Galver, J. Martensson, “Modeling WDM wavelength switching systems for use in GMPLS and automated path computation,” IEEE/OSA J. Optical Comm. Netw., vol. 1, no. 1, pp. 187–195, Jun. 2009. DOI: http://dx.doi.org/10.1364/JOCN.1.000187.
- N. Sambo, N. Andriolli, A. Giorgetti, P. Castoldi, “Wavelength Preference in GMPLS-controlled Wavelength Switched Optical Networks,” Network Protocols and Algorithms, vol. 3, no. 2, pp. 110–125, 2011. http://www.macrothink.org/journal/index.php/npa/article/view/819/704
- A. Farrel and I. Bryskin, “GMPLS architecture and applications,” The Morgan Kaufmann Series in Networking, 2006.