Patents Represented by Attorney, Agent or Law Firm Dallas F. Smith
  • Patent number: 6366716
    Abstract: A single Hybrid Optical Integrated Circuit that contains an optical switch having six groups of ports using micro-electron mechanical or six-port MEMS for short, amplifiers, laser pumps (or inputs from laser pumps) in a single package. This is done either by providing alignment features between the MEMS devices and the amplifier silicon substrate, or by building both on a common silicon substrate. The optical switching device provides the expansion capability and add/drop functionality desired via the optical expansion input and output ports and the optical inter-matrix input and output ports, respectively. Additionally, since these separate matrices of divertors are used to selectively couple the ports of the device, less divertors are required than if one large matrix of divertors were used. Further, the optical path length, a major issue in the design of such devices, is less in this structure than it would be in a single MEMS crosspoint providing a similar function.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: April 2, 2002
    Assignee: Nortel Networks Limited
    Inventor: Alan F. Graves
  • Patent number: 6178178
    Abstract: A switching module provides connection of a processor to a redundant local area network. Redundant access units switch control selects the access unit used by the processor based on the status of each local area network. In particular, two 10BaseT Ethernet LANs are monitored by scanning for respective link beats or data.
    Type: Grant
    Filed: April 24, 1998
    Date of Patent: January 23, 2001
    Assignee: Nortel Networks Limited
    Inventors: Raymond Bruce Wallace, Alexandra Michelle Dopplinger, David Longbottom
  • Patent number: 6079036
    Abstract: In an Intelligent Network (IN) a method for acquiring data is provided. The method comprises a test call initiated from the SSP to a desired destination within the network. The test call with the log portion appended to TCAP (and ISUP) messages travel through the network and collects data in the log portion from each node on the test call path. The test call with the traveling log (TLog) helps the maintenance personnel isolate troubles and faults in the network without having to monitor each node (or office) on the route of a troubled message path.
    Type: Grant
    Filed: October 19, 1995
    Date of Patent: June 20, 2000
    Assignee: Nortel Networks Corporation
    Inventor: Omayma El-Sayed Moharram
  • Patent number: 6073031
    Abstract: A telephone base unit for use with a mobile telephone handset comprises means for interfacing the handset with the base unit for enabling user definable data entry key settings of the handset to be downloaded and emulated at the base unit such that when interfaced with the base unit, the mobile telephone handset operates to enable the use of the base unit as a wireless desktop interface. The interface means is comprised of means for transferring user definable data entry key settings of the handset to the base unit, means for storing the user definable data entry key settings of the handset at said base unit and controller means to enable a user to use the user definable data entry key settings with the user interface of the base unit to receive incoming and make outgoing calls from the base unit via the mobile telephone handset.
    Type: Grant
    Filed: December 24, 1997
    Date of Patent: June 6, 2000
    Assignee: Nortel Networks Corporation
    Inventors: Edmond J. Helstab, Jeffrey L. Fairless, Michael C. G. Lee, Neal T. Cowan, Jonathan Crone, Edward L. Pugh, Robert E. Bradley
  • Patent number: 6064241
    Abstract: A direct digital frequency synthesizer includes inputs for a reference clock signal and a control word, and an output for a synthesized clock signal. A phase accumulator coupled to the input for the control word and the reference clock signal has an output for a phase control signal. A phase shifter has inputs for the reference clock signal and the phase control signal and an output coupled to the output for the synthesized clock signal. The control word can be used to adjust the output frequency and phase of the synthesized clock signal.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: May 16, 2000
    Assignee: Nortel Networks Corporation
    Inventors: Steve D. Bainton, Matthew D. Brown
  • Patent number: 6058144
    Abstract: A data pulse receiver for detecting and amplifying substantially attenuated data pulses received at gigabit-per-second rates from a differential coupler with outputs having asymmetrical dc characteristics. The receiver, in a preferred embodiment, has grounded base differential amplifiers to give impedance matching, a biasing resistor connected to a separate ground terminal for biasing one of the differential amplifiers, and a matching resistor, connected at only one of its terminals, to compensate for the stray capacitance of the biasing resistor. A regenerative flip-flop with programmable tail current provides hysteresis in order to suppress unwanted noise. The receiver may also include means for automatic adjustment of the hysteresis level.
    Type: Grant
    Filed: April 3, 1998
    Date of Patent: May 2, 2000
    Assignee: Nortel Networks Corporation
    Inventor: Anthony Kevin Dale Brown
  • Patent number: 6049606
    Abstract: The invention provides an audio subsystem for use in a telephone terminal operable in handsfree mode and comprises a receive path including a receive transducer for generating audio signals from a received signal and a transmit path including a transmit transducer for converting audio signals to electrical signals for transmission to a far-end user. An acoustic echo canceller is communicatively coupled between the receive path and the transmit path and includes a subtractor circuit connected serially with the transmit transducer. The echo canceller is responsive to control signals for controlling the subtractor circuit. The subsystem comprises means for detecting a near-end talking condition including first circuit means for measuring the level of the total energy of the out-of-telephony-band components in the signal from the transmit transducer and circuit means for comparing the energy level represented by an output signal from the first measurement circuit to a first predetermined threshold.
    Type: Grant
    Filed: December 11, 1997
    Date of Patent: April 11, 2000
    Assignee: Nortel Networks Corporation
    Inventors: Heping Ding, Frank Lau
  • Patent number: 6040933
    Abstract: A method and apparatus for channel performance equalization in wavelength division multiplexed (WDM) systems is disclosed. Performance of the channels is estimated from optical power measurements of each signal transmitted by the channels. The measurements are taken at the inputs of optical amplifiers in the transmission path of the system. The channels are equalized by adjusting the optical power of the channel transmitters. The method is applicable to point-to-point networks as well as more complex network configurations such as those having an add-drop multiplexer (ADM) for inserting and extracting channels from the transmission path. The method can compensate for signals having different bit rates by applying an offset to the amount of optical power adjustment of the channel transmitters.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: March 21, 2000
    Assignee: Nortel Networks Corporation
    Inventors: Farideh Khaleghi, Alan Glen Solheim, Chris Wilhelm Barnard
  • Patent number: 6014707
    Abstract: This invention relates to a method and protocol to enable a simple, reliable and highly scaleable data transfer facility in a digital data network. In communication a server and a client within a data processing system, the method of transferring data from the server to the client comprises requesting, by the client, transfer of the data in accordance with a transfer unit size specified by the client The server transmits the data in successive blocks having a size based on the client specified transfer unit size, till all the data has been transferred, and the server delays at least a predetermined time period between transmission of successive blocks. This connectionless, unacknowledged data transfer protocol minimizes resource utilization at the data server and is combined with source rate control to reduce congestion in the intervening network.
    Type: Grant
    Filed: November 15, 1996
    Date of Patent: January 11, 2000
    Assignee: Nortel Networks Corporation
    Inventors: Scott Edward Miller, David Michael Alexander
  • Patent number: 5852637
    Abstract: A data pulse receiver for detecting and amplifying serial data pulses received at gigabit-per-second rates over a transmission medium through which the signal levels have been substantially attenuated. The receiver, in a preferred embodiment, has grounded base differential amplifiers to give impedance matching, signal amplification and wide frequency bandwidth. A regenerative flip-flop with programmable tail current provides hysteresis in order to suppress unwanted noise signals. The flip-flop also returns the data pulses to NRZ format. The receiver may also include means for automatic adjustment of the hysteresis level.
    Type: Grant
    Filed: December 7, 1995
    Date of Patent: December 22, 1998
    Assignee: Northern Telecom Limited
    Inventors: Anthony Kevin Dale Brown, Richard Ralph Goulette, Roderick Edgar Wallace, Rodney David Pike
  • Patent number: 5825860
    Abstract: In the Intelligent Networks environment, where multiple Service Providers and multi-Vendor equipment are involved in new service offering, the risk of overloading the network elements are real and managing the traffic is a challenge. Network traffic overloads could result from equipment failures, major equipment outages, or widespread loads above engineered levels. To solve the problem of network traffic overload, a Mediation Point (MP) is connected to a group of service control points (SCP). The MP includes control feature to balance the load and manage the overload controls for the multiple SCPs that are deployed in load sharing mode in the network.
    Type: Grant
    Filed: March 12, 1997
    Date of Patent: October 20, 1998
    Assignee: Northern Telecom Limited
    Inventor: Omayma El-Sayed Moharram
  • Patent number: 5812653
    Abstract: The invention manifests a secure, on-demand meet-me conferencing service embodied within a telephone network having an advanced intelligent network (AIN) infrastructure. Centralized control of conferencing bridges located in network switches is effected at a service control point (SCP) in the AIN telephone network. Users of the service first subscribe to it, and are assigned a primary authorization code, a code assignment directory number (DN) and a conference DN at that time. Before a conference, a subscriber calls the code assignment DN, provides the primary authorization code, and receives a secondary authorization code for distribution to persons who will be participants of the conference call. At the time of the conference, the subscriber dials the conference DN and provides the primary authorization code to the conferencing service to initiate the conference call. The participants then dial the conference DN and use the secondary authorization code to access the conference.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: September 22, 1998
    Assignee: Northern Telecom Limited
    Inventors: Sylvain Jodoin, Joanne Pilkington, Pierre Belzile, Charles Meubus
  • Patent number: 5812652
    Abstract: The invention manifests a secure, on-demand meet-me conferencing service embodied within a telephone network having an advanced intelligent network (AIN) infrastructure. Centralized control of conferencing bridges located in network switches is effected at a service control point (SCP) in the AIN telephone network. Routing and availability information with respect to the conferencing bridges is maintained by the SCP. When the SCP in communication with a network switch processing a call determines that the call is to initiate a conference, a bridge is allocated to the call. The availability information of the bridge is then updated and the SCP provides the network switch with routing instructions for connecting the call through the telephone network to the bridge.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: September 22, 1998
    Assignee: Northern Telecom Limited
    Inventors: Sylvain Jodoin, Joanne Pilkington, Pierre Belzile, Charles Meubus
  • Patent number: 5809491
    Abstract: A system for generating an exception report for a particular problem based on call traffic. The system maintains a count of occurrences for that problem, happening within a sliding window of call traffic volume. When the count exceeds a threshold value, the system generates the exception report whereby appropriate action may be initiated to correct the problem.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: September 15, 1998
    Assignee: Northern Telecom Limited
    Inventors: Inanc Kayalioglu, John Andrew McBrayne, Maryam M. Sheidafar, Steven L. Sauder
  • Patent number: 5781770
    Abstract: A processor shelf controller monitors processor shelf status. On shutdown or reset request either initiated by a central controller or the processor shelf, the processor shelf controller provides at least a first timer that allows the operating processor shelf sufficient time to shutdown operating system processes. For graceful shutdowns, a second timer is provided to allow the operating processor shelf to clear all application related processes prior to start of the first timer.
    Type: Grant
    Filed: October 24, 1996
    Date of Patent: July 14, 1998
    Assignee: Northern Telecom Limited
    Inventors: Russell Francis Byers, Joseph Marcel Gilles Duchaine, Michael Leonard Schuett, Cornelius Jacob Grootenboer
  • Patent number: 5671259
    Abstract: A clock recovery circuit includes a resonant circuit which has a varactor diode and is driven into oscillation at a variable frequency in response to a control voltage fed to the varactor diode. Basically, the resonant circuit is tuned into the clock frequency of an incoming binary data signal. The clock recovery circuit provides a clock signal which is associated with a data output signal. The desired transition timing of the clock signal is at mid-point of the incoming binary data signal. When the transition timing is advanced or delayed from the mid-point due to changes in the resonant frequency of the circuit, the control voltage changes, with the result that the tuning frequency of the resonant circuit is varied. In response to the change of the resonant frequency, the transition timing of the clock output signal is delayed or advanced. This condition is detected and the control voltage fed to the varactor is changed, resulting in achievement of correct transition timing.
    Type: Grant
    Filed: August 24, 1995
    Date of Patent: September 23, 1997
    Assignee: Northern Telecom Limited
    Inventors: Robert McLaren Thomas, John Staal Nielsen
  • Patent number: 5594893
    Abstract: A processor shelf controller monitors processor shelf status. On shutdown or reset request either initiated by a central controller or the processor shelf, the processor shelf controller provides at least a first timer that allows the operating processor shelf sufficient time to shutdown operating system processes. For graceful shutdowns, a second timer is provided to allow the operating processor shelf to clear all application related processes prior to start of the first timer.
    Type: Grant
    Filed: June 1, 1994
    Date of Patent: January 14, 1997
    Assignee: Northern Telecom Limited
    Inventors: Russell F. Byers, Joseph M. G. Duchaine, Michael L. Schuett, Cornelius J. Grootenboer
  • Patent number: 5561692
    Abstract: A circuit for providing a phase controlled clock output includes a ring oscillator having a delay line for providing an internal clock signal whose period varies with on-chip variations due to temperature, voltage, and process. The circuit also includes a clock phase select circuit having a counter and divider for determining the number of delays in one external clock period and an input for a phase select value. A delay line having delay elements similar to those of the ring oscillator provides multiple delayed clock signals from the reference clock signal. A multiplexor having odd and even sides is used to select the desired clock signal in a glitchless manner. The phase controlled clock signal output is controlled by the phase select signal and is compensated for on-chip variations due to temperature, voltage, and process.
    Type: Grant
    Filed: December 9, 1993
    Date of Patent: October 1, 1996
    Assignee: Northern Telecom Limited
    Inventors: Roger J. Maitland, Hal H. Ireland
  • Patent number: 5526464
    Abstract: A code-excited linear prediction (CELP) coding method and code divide the residual signal into frequency bands. Codebooks provided for each band decrease in size with increasing band frequency. Reduction in codebook size with increasing frequency together with reduction in sampling rate with decreasing frequency provide reductions in codebook search complexity that allow real time implementation on digital signal processor chips.
    Type: Grant
    Filed: April 29, 1993
    Date of Patent: June 11, 1996
    Assignee: Northern Telecom Limited
    Inventor: Paul Mermelstein
  • Patent number: 5515475
    Abstract: A method of recognizing speech comprises searching a vocabulary of words for a match to an unknown utterance. Words in the vocabulary are represented by concatenated allophone models and the vocabulary is represented as a network. On a first pass of the search, a one-state duration constrained model is used to search the vocabulary network. The one-state model has as its transition probability the maximum observed transitional probability (model distance) of the unknown utterance for the corresponding allophone model. Words having top scores are chosen from the first pass search and, in a second pass of the search, rescored using a full Viterbi trellis with the complete allophone models and model distances. The rescores are sorted to provide a few top choices. Using a second set of speech parameters these few top choices are again rescored. Comparison of the scores using each set of speech parameters determines a recognition choice. Post processing is also possible to further enhance recognition accuracy.
    Type: Grant
    Filed: June 24, 1993
    Date of Patent: May 7, 1996
    Assignee: Northern Telecom Limited
    Inventors: Vishwa N. Gupta, Matthew Lennig