Northern Telecom Limited

Nortel Networks Corporation

Ranovus Inc.

David John Nicholson

David Wright Martin

Alan Glen Solheim

Mohammed Ismael Tatar

Ronald Joseph Gagnon

Mark Stephen Wight

Timothy James Armstrong

Dylan Logan

Kim Bryon Roberts

Donald Russell Ellis

Juergen Hauenschild

Wang-Hsin Peng

Douglas J S Beckett

Yves Tremblay

James A McEachern

Dino Cosimo DiPerna

Jürgen Hauenschild

Richard Romagnino

Jeffrey Otha Hutchins

Dino Diperna

Thomas P Flanagan

Wayne Ergle

John B Mills

Douglas Beckett

A device that includes a multi-segment ring modulator is provided. In particular, the device comprises: an optical waveguide; an optical ring modulator optically coupled to the optical waveguide; a first voltage control device along a first segment of the optical ring modulator; a second voltage control device along a second segment of the optical ring modulator; a first driver device configured to control the first voltage control device to a first voltage and a second voltage; and, a second driver device configured to control the second voltage control device to a third voltage and a fourth voltage. In particular implementations, a ratio of a length of the first segment to a length of the second segment can be one or more of about 2:1 and greater than 1:1, and non-linear driver devices can be used.

Multi-segment ring modulator

A single laser multi-frequency transmitter is provided, comprising: a laser generating given modes; an optical input bus; a common optical output bus; coupling optics coupling the laser to the optical input bus; a plurality of ring resonator filters: arranged in series along the optical input bus in a one-to-one relationship with a sub-band of the given modes; optically coupled to both the optical input bus and the common optical output bus; and each configured to couple one respective frequency from the sub-band to the common optical output bus; and, a plurality of ring resonator modulators: arranged in series along the common optical output bus in a one-to-one relationship with the plurality of ring resonator filters; and each configured to modulate one given respective frequency from the sub-band so that all modes in the sub-band are modulated on the common optical output bus.

Single laser multi-frequency transmitter

A configuration for a transport node of a telecommunication system comprises a pair of transparent mux/demuxs provided at two sites and connected over a high rate span. The T-Muxs provide continuity of all tribs and maintain a lower bit rate linear or ring system through the higher bit rate span. The lower bit rate linear or ring system operates as if it were directly connected without the higher bit rate midsection. For the forward direction of the traffic, the T-Mux comprises a multi-channel receiver for receiving a the trib signals and providing for each trib signal a trib data signal and a trib OAM&P signal. The data signals are multiplexed into a supercarrier data signal and the OAM&P signals are processed to generate a supercarrier OAM&P signal. A supercarrier transmitter maps the supercarrier data signal and the supercarrier OAM&P signal into a supercarrier signal and transmits same over the high rate span. Reverse operations are effected for the reverse direction of traffic. With this invention, an entire ring system does not have to be upgraded to a higher line rate due to fiber exhaust on a single span. The invention is particularly applicable to SONET OC-48/OC-12/OC-3 linear and ring networks and the high rate span could be an OC-192 line.

Transparent transport

Architectures for a synchronous transport network of a telecommunications system using transparent transport capabilities are presented. The telecommunications network comprises a pair of transparent multiplexers (TMuxs) connected over a bidirectional high speed span for transparently transporting high rate traffic. Each TMux consolidates traffic from a plurality (I) of linear systems or a plurality of bidirectional self-healing rings, each ring (K,) having a ring rate R,and at least two nodes (A,, B,). In another configuration, each TMux subtends a plurality of rings, such TMuxes being adapted for connection as ring nodes in a high-speed ring. The upgrades obtained with TMuxes in both the linear and ring configurations provide for per span relief for fiber exhaust where no changes to the existing systems are desired. As well, the bandwidth of an existing system may be increased on a per-span basis or the equipment count may be reduced.

Network architectures with transparent transport capabilities

A configuration for a SONET transport node comprises a pair of transparent mux/demuxs provided at two sites and connected over a high rate span. The T-Muxs provide continuity of all tribs and maintain a lower bit rate linear or ring system through the higher bit rate span. The lower bit rate linear or ring system operates as if it were directly connected without the higher bit rate midsection. For the forward direction of the traffic, the T-Mux comprises a multi-channel receiver for receiving the trib signals and providing for each trib signal a trib SPE and a trib OH. The trib SPEs are multiplexed into a supercarrier SPE and the trib OHs signals are processed to generate a supercarrier OH. A supercarrier transmitter maps the supercarrier SPE and the supercarrier OH into a supercarrier signal and transmits same over the high rate span. Reverse operations are effected for the reverse direction of traffic. With this invention, an entire ring system does not have to be upgraded to a higher line rate due to fiber exhaust on a single span. The invention is particularly applicable to OC-48/OC-12/OC-3 linear and ring networks and the high rate span could be an OC-192 line.

Transparent multiplexer/demultiplexer

A communications system is provided having SONET communications channels extending between first and second locations. The channels include pairs of forward and reverse channels for carrying traffic in normal operation between first and second locations and a protection channel for carrying traffic of one channel in the event of a fault. Each pair of forward and reverse channels is provided on a shelf at each location, the shelves having the same relative position at both locations and the protection channel is provided on a protection shelf. The protection channel includes, between the first and second locations, a forward optical link and a reverse optical link and at each of the first and second locations, a single protection loop, coupling the forward and reverse optical links, that forms the protection channel. The protection loop is used to provide, at each location, a local virtual protection loop for indicating the protection requirements and status of the respective location, and a remote virtual protection loop for indicating the protection requirements and status of the location remote from the respective location. The local protection loop is provided by inserting K1 and K2 bytes into E1 slots of STS-1 #25 and #2, respectively. The remote protection loop is provided by inserting K1 and K2 bytes into E1 slots of STS-1 #26 and #3, respectively.

Communications system with a single protection loop

A transmission system comprises nodes coupled in a ring via two multiplexed transmission paths having opposite transmission directions. The two paths can be time, space, or wavelength division multiplexed. Bidirectional communications between any two nodes are provided in normal operation using both paths around a first, most direct, part of the ring. In the event of a fault affecting such communications, a protection switch is made to maintain bidirectional communications between the two nodes using both paths around a second, remaining, part of the ring. In this manner, each path can simultaneously carry both normal and protection switched signals. In an embodiment of the invention, only the two nodes adjacent a fault need be aware of the fault, each of these nodes effecting a protection switch for signals terminated at the node and effecting a protective loopback for other signals needing protection. The invention enhances the total capacity of the paths for carrying normal and protection switched signals. A network may comprise a plurality of such ring transmission systems intersecting at at least one network node, the network node comprising a node of each ring and a cross connect switch for switching signals therebetween.

Ring transmission system

A binary data signal is regenerated with respect to three threshold levels, one of which is derived from and lies between the other two so that it is an optimum level for producing a regenerated output signal. Two control loops are used to produce the other two threshold levels to produce regenerated signals with predetermined error rates, the errors occurring on the two control loops for the two respective states of the binary data signal, whereby the optimum threshold level is maintained regardless of the nature of signal degradation. The arrangement provides rapid performance monitoring which can also be used to adjust other parameters, such as detector bias, equalizer tuning, and clock phase, for optimum performance in an active and ongoing manner.

Binary data regenerator with adaptive threshold level

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Ottawa, Canada

David John Nicholson