Network Architecture for an All-optical Internet

To meet the growing need for higher capacities, a new architecture for an all-optical Internet is proposed. Based on traffic statistics and number of available wavelengths in the WDM trunks at network nodes, wavelength allocation and assignment is performed. Distribution of wavelength allocation decisions is accomplished using signaling messages encapsulated in optical “labels” or “tags” associated with each wavelength channel. Signaling messages are generated and modulated onto the individual wavelength channels at the nodes. These messages are then used to reflect changes in the network configuration at each optical element. Wavelength-selective and wavelength-interchanging cross-connects form the basic building blocks of an all optical network. In response to the signaling commands, each optical crossconnect reconfigures itself based on pre-determined wavelength assignments, generates and forwards new signals to the downstream elements. Since labels are associated with wavelength channels, they may be exchanged across wavelength changers without modification. Exchange of allocation commands and wavelength updates are performed periodically. The assignment of WDM wavelengths remains unchanged until traffic at the access points to the network differ significantly from the previous decision interval and also based on the wavelength routing process.