Nortel Networks Corporation

Mitel Corporation

Gino Totti

Kexing Liu

Michel Pigeon

David Milton

Tomas Valis

Conrad Lewis

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.

WDM optical network with passive pass-through at each node

Technique for detecting noise on a data channel

WDM optical network and switching node with pilot tone communications

A digital switching system which is comprised of a circuit switching network under control of a main system control for carrying and switching transmission paths for signals transmitted between peripherals (i.e. lines, trunks, service circuits, etc.), and a separate message switching network under control of the main system control for carrying supervisory and control signals related to the status of the peripherals between peripheral unit management circuit controller(s) and the main system control.

Switching system with separate supervisory links

Growing community of inventors

Kanata, Canada

Gino Totti