Nortel Networks Corporation

Northern Telecom Limited

Other

Alcatel Lucent

Ciena Corporation

Alcatel-lucent USA Inc.

Innovance, Inc.

Mark Stephen Wight

Alan Glen Solheim

Mohammed Ismael Tatar

Ronald Joseph Gagnon

David Wright Martin

David John Nicholson

Timothy James Armstrong

Christian Scheerer

Stephane Gagnon

Jingyu Zhou

Robert Au-Yang

Gerard Leo Swinkels

Roland A Smith

Kevan Peter Jones

Petre Popescu

Gwendolyn Kate Harris

Thomas E Moore

James A McEachern

Mei Du

Paul Edward Beer

Hamid R Mehrvar

Gwenda Lindhorst-Ko

Valerie A Van Alstine

Trevor D Corkum

Mervin Doda

Andreas Franz Ludwig Sizmann

Peter J Barry

Xiaoming Fan

Kalamaljit S Masonde

Kathryn Louise Howlett

David Woods

Ian I Grant

Bernard Lemieux

Stephen H Brazeau

Methods for transfer of bulk data from a leader device to a follower device over a bus are described. The methods employ address frames and write frames. The bus, the address frames, and the write frames are compatible with Clause 45 of IEEE Std 802.3-2015. The methods achieve a reduction in the number of frames employed to transfer data as contrasted with conventional indirect write transactions. After transmitting on a Management Data Input/Output (MDIO) data signal an address frame that specifies the follower device and that contains the address of an initial register, the leader device proceeds to transmit on the MDIO data signal multiple write frames that specify the target follower device, the multiple write frames transmitted one at a time, each write frame containing a different block of the bulk data. A follower device implements a post-write-increment-address action, despite the absence of any definition in Clause 45 of IEEE Std 802.3-2015 of a post-write-increment-address frame.

Bulk data transfer over MDIO (clause 45) bus

A method for engineering of a connection in a WDM photonic network with a plurality of flexibility sites connected by links comprises calculating a physical end-to-end route between a source node and a destination node and setting-up a communication path along this end-to-end route. An operational parameter of the communication path is continuously tested and compared with a test threshold. The path is declared established whenever the operational parameter is above the margin tolerance. The established path is continuously monitored by comparing the operational parameter with a maintenance threshold. A regenerator is switched into the path whenever the operational parameter is under the respective threshold, or another path is assigned to the respective connection. An adaptive channel power turn-on procedure provides for increasing gradually the power level of the transmitters in the path while measuring an error quantifier at the destination receiver until a preset error quantifier value is reached. As the connection ages, the power is increased so as to maintain the error quantifier at, or under the preset value. The path operation is controlled using a plurality of optical power/gain control loops, each for monitoring and controlling a group of optical devices, according to a set of loop rules.

Method for engineering connections in a dynamically reconfigurable photonic switched network

A method and system for conveying an arbitrary mixture of high and low latency traffic streams across a common switch fabric implements a multi-dimensional traffic classification scheme, in which multiple orthogonal traffic classification methods are successively implemented for each traffic stream traversing the system. At least two diverse paths are mapped through the switch fabric, each path being optimized to satisfy respective different latency requirements. A latency classifier is adapted to route each traffic stream to a selected path optimized to satisfy latency requirements most closely matching a respective latency requirement of the traffic stream. A prioritization classifier independently prioritizes traffic streams in each path. A fairness classifier at an egress of each path can be used to enforce fairness between responsive and non-responsive traffic streams in each path. This arrangement enables traffic streams having similar latency requirements to traverse the system through a path optimized for those latency requirements.

Traffic switching using multi-dimensional packet classification

The topology of a network is represented, or emulated, by a topology engine comprising processing elements interconnected via a connection matrix. Queries representing physical problems of the network are supplied by a host processor to the topology engine, where they are processed in the processing elements in accordance with the topology to produce responses which are returned to the host processor. In particular, the network can be a communications network and the queries can comprise search requests for determining connection paths between devices of the network. The topology engine can use processors with multiple instances so that it is more compact than the communications network that it represents.

Method of addressing physical problems of a topological network using a topology engine

The present invention provides a method and apparatus for establishing dedicated local area network (LAN) connectivity between network elements (NEs) in an optical transmission network without using any of the payload transport capacity available. In order to provision dedicated LAN connections between NEs, the invention reallocates existing overhead functionality to provide dedicated bandwidth for LAN communications between NEs. At each NE, a respective LAN interface unit provides access to this dedicated bandwidth and allows LAN devices such as personal computers (PCs), servers and monitoring equipment to communicate across NEs of an optical transmission network without consuming any payload transport capacity available therein.

Method and apparatus for establishing dedicated local area network N) connections in an optical transmission network

A device for measuring dispersion of a link between two switching nodes of an optical network comprises a phase measuring unit PMU for determining a first phase of a data signal traveling on a first wavelength &lgr; , and a second phase of the same data signal traveling on a second wavelength &lgr; , received consecutively over the link under measurement. A dispersion measurement controller controls operation of the phase measuring unit and characterizes the dispersion of the link at a wavelength of interest &lgr;&equals;(&lgr; )/2, based on the first and second phases. The PMU includes a frame detector for determining a first and a second rotation signal indicative of the digital offset between the first and second test clocks with a respective frame start, and a phase detector for measuring the phase of these test clocks with respect to a static reference. The static reference is provided by the same data signal transmitted continuously over a reference wavelength. The test and reference clocks are 1:n divided to extend the range of the measurement. A method for characterizing the dispersion of a link of an optical network is also provided.

Dispersion measurement in optical networks

A line amplification system connected on the fiber between two flexibility sites of a wavelength switched network is built with a number of modules that can be arranged in a line amplifier, preamplifier and postamplifier configurations. The line and preamplifiers include a Raman module and a two-stage EDFA module provided with mid-stage access. A dynamic gain equalizer is connected in the mid-stage in the line amplification configurations. As well, dispersion compensating module may be connected in the mid-stage whenever/if needed. A line monitoring and control system operates the line amplification system so that all channels traveling along a link have substantially the same power, in the context of channels being added and removed to/from the line arbitrarily.

Line amplification system for wavelength switched optical networks

A peak detector for measuring the voltage amplitude of low amplitude balanced digital signals. The N-diode peak detector uses the non-linear characteristics of a diode to convert a high speed low amplitude input signal into a DC voltage, linearly proportional to the signal amplitude (peak). A compensation circuit is designed to match the characteristics of a digital modulation signal and track over a large range of temperatures and signal amplitudes. The circuit can be used for digital and analog modulation signals. For analog signals, the peak detector uses a larger number of diodes or a reduced range.

N-diode peak detector

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

A message hub is provided for use in a message communication system having a plurality of nodes connected to the message hub by a data communication medium for inter-node messaging. The message hub operates in a scheduling phase and a transmission phase. In the scheduling phase, request receiving means receives a messaging request signal is received from each node. In accordance with the messaging request signal, selecting means selects a selected node in the scheduling phase. Granting means generates a grant signal to the selected node for allowing the selected node to transmit a message to the message hub on the data communication medium. The granting means also generates a listen signal to the other nodes for commanding the other nodes to listen to the data communication medium. The message hub enters in the transmission phase in which message receiving means receives a message transmitted from the selected node on the data communication medium. The message includes an end of message signal at the end of the message. The message is then broadcasted by broadcasting means to all nodes on the data communication medium so as to enter into the scheduling phase by broadcasting the end of message signal.

Message hub

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 gain control amplifier includes an input differential circuit having a pair of transistors, the emitters of which are coupled via a pair of emitter resistors. The input differential circuit includes a current sink for providing an operating current. With variation of the operating current, the gain control amplifier's gain is varied. Two emitter coupled differential amplifiers are connected to the input differential circuit having a current sink. A current flowing in the transistors of the emitter coupled differential amplifier and the input differential circuit is split by an additional emitter coupled differential circuit having a current sink. A current splitting factor is controlled in response to the voltage difference between the collectors of the two transistors of the two emitter coupled differential amplifiers. Since the relatively small currents flow in the emitter resistors, noise caused thereby is relatively low. Thus, it provides a wide input dynamic range with low noise. The gain control amplifier is used in a variable gain amplifier and an automatic gain control amplifier.

Gain control, variable gain and automatic gain control amplifiers including differential circuit transistors and current splitter

It is an object of the invention to provide a peak detector with improved precision for low amplitude AC signals for a broad range of input frequencies. One embodiment of the invention is broadly defined as an AC peak detector for receiving an input signal and a negative DC potential and providing an inverted peak output signal approximating an inverted steady state peak of the input signal, the AC peak detector comprising: a semiconductor junction means for receiving the input signal and the inverted peak output signal, and generating a correction signal proportional to an exponential function of the input signal and the inverted peak output signal; a resistance means for receiving the correction signal and sinking a bias current through the semiconductor junction means to the negative DC potential, such that the current/voltage characteristic of the semiconductor junction remains in an exponential region; and an amplifying means for receiving the correction signal and amplifying and inverting the correction signal to produce the inverted peak output signal, and for sourcing the constant bias current.

Low amplitude peak detector

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.

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Ottawa, Canada

Mark Stephen Wight