MINIMIZING BANDWIDTH NARROWING PENALTIES IN A WAVELENGTH SELECTIVE SWITCH OPTICAL NETWORK

摘要

This invention relates to provisioning wavelength-selective switches and reconfigurable optical add-drop multiplexers to minimize the bandwidth narrowing effect from the optical filters. Novel architectures and methods are disclosed that can significantly reduce bandwidth-narrowing on channels in a reconfigurable WDM network where a large number of optical filter elements are cascaded. Instead of blocking unused channels as in the prior art, unused channels are selectively provisioned depending on the state of their adjacent channels. Unused adjacent channels of an active channel are provisioned to follow the same path as the active channels. As each channels is deployed, the channel frequency is selected so as to minimize bandwidth narrowing.

主权项

1. A method for provisioning a channel on which a client signal will be transmitted along a path from a source node through at least one intermediate node before reaching a destination node of a WDM optical network, the method comprising the following steps:
(a) selecting a signal channel and a path on which the client signal will be transmitted among a plurality of nodes of the network; (b) configuring an optical filter at each node along the path to reflect the state of the signal channel at that node; (c) determining, with respect to each node along the path, whether each of two channels adjacent to the signal channel is unused; and (d) configuring the optical filter at each node along the path by setting the state of each unused adjacent channel to the same physical state as that of the signal channel, (e) thereby effectively increasing the spectral passband of the client signal.