US 6,748,174 B2 · WDM optical network with passive pass-through at each node

Abstract

A communications network has a plurality of nodes interconnected by an optical transmission medium. The transmission medium is capable of a carrying a plurality of wavelengths organized into bands. A filter at each node for drops a band associated therewith and passively forwards other bands through the transmission medium. A device is provided at each node for adding a band to the transmission medium. Communication can be established directly between a pair of nodes in the network sharing a common band without the active intervention of any intervening node. This allows the network to be protocol independent. Also, the low losses incurred by the passive filters permit relatively long path lengths without optical amplification.

Claims8

Dependent claims

A set of interfaces for use in a communications network in which pairs of nodes of the network are associated with distinct bands of optical channels used for communication between said pairs of nodes, each interface comprising:

an optical band demultiplexer for separating a selected band of optical channels from non-selected bands of optical channels and passively forwarding the non-selected bands of optical channels;
and
an optical band multiplexer for combining a band of optical channels with the passively forwarded non-selected bands of optical channels;
the set of interfaces being constructed such that each band of optical channels comprises a plurality of distinct optical channels at respective distinct wavelengths, and adjacent bands are separated by at least one wavelength channel which is not used for communicating information.

1 more element

Dependencies are inferred from the claim text.

WDM optical network with passive pass-through at each node

Life of this patent

WDM optical network with passive pass-through at each node

Life of this patent

Abstract

Claims8