Patents Assigned to Nortel Networks
  • Patent number: 6600920
    Abstract: A system for delivering a call to a mobile unit in a wireless network includes a mobile switching center that receives a call setup request message initiated in response to a request from an originating mobile switching center. The receiving mobile switching center initiates setting up the call between the receiving mobile switching center and the mobile unit before the call is setup between the receiving mobile switching center and the originating mobile switching center. Preferably, the receiving mobile switching center initiates setting up the call by issuing a page in response to receiving the call setup message.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: July 29, 2003
    Assignee: Nortel Networks Limited
    Inventors: Gary Boyd Stephens, Andrew Silver
  • Patent number: 6601150
    Abstract: A memory management technique for maintaining packet order in a packet processing system involves maintaining a START indicator and a VALID indicator for each memory block in a packet memory. Packets are written in a number of successive memory blocks, and the START indicator corresponding to the first memory block of the number of successive memory blocks is set to indicate that the packet is available for processing. The packets are processed by a packet processor. When the packet processor completes the processing of a particular packet, the VALID indicator corresponding to the first memory block associated with that packet is set to indicate that the packet is ready to be forwarded. The packet may become ready to be forwarded out of order.
    Type: Grant
    Filed: May 10, 1999
    Date of Patent: July 29, 2003
    Assignee: Nortel Networks Limited
    Inventors: Marvin Scheinbart, Geoffrey B. Ladwig, Richard Angle
  • Patent number: 6600749
    Abstract: A syntactical representation is used to generate data describing a hierarchical broadband network and relationships between it elements. The format of the syntactical representation resembles logic programming language clauses. The syntactical representation is used to specify a broadband connection problem to be solved. Data describing physical resources and functionality of a set of network elements is entered into an inference engine which applies an algorithm to its input in order to find a solution to a specified connections planning problem. The algorithm is recursive and uses artificial intelligence techniques; such as, first fail hierarchical planning and hill-climbing to guide the inference engine's search for a solution.
    Type: Grant
    Filed: November 18, 1999
    Date of Patent: July 29, 2003
    Assignee: Nortel Networks Limited
    Inventors: Clive Colin Hayball, Nigel Lawrence Bragg, Niall Forbes Ross, Andrew J Tunnicliffe
  • Patent number: 6600395
    Abstract: A technique for facilitating signal transmission at high signal frequencies in a multi-layer substrate is disclosed. In one embodiment a multi-layer substrate comprises a conductor or pair of conductors, a first dielectric layer on a first side of the conductor or pair of conductors and a second dielectric layer on a second side of the conductor or pair of conductors. An air channel is provided in the first dielectric layer, the air channel formed to be substantially coextensive with the conductor or pair of conductors. A conductive shield surrounds the conductor or pair of conductors, the first dielectric layer, and the second dielectric layer in order to eliminate crosstalk. The conductor or pair of conductors may have discrete spaced edges and the width of the conductor or pair of conductors may be increased in order to adjust the impedance because of the low dielectric constant of air. Furthermore, additional air channels and a supporting layer may be included in the structure.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: July 29, 2003
    Assignee: Nortel Networks Limited
    Inventors: Martin R. Handforth, Herman Kwong, Richard R. Goulette
  • Patent number: 6601090
    Abstract: An object caching system (100) serving an Intranet (102) includes a cache name server (106) and a plurality of web cache servers (108A-108D). Each of the plurality of web cache servers (108A-108D) couples to an Intranet (104) and to the Internet (102) and stores a respective plurality of Internet objects that have been previously retrieved from the Internet (102). The cache name server (106) couples to the Intranet (104), receives a request for an Internet object from a web client (110A) coupled to the Intranet (104), and directs the web client (110A) to a serving web cache server (108A) of the plurality of web cache servers (108A-108D) based upon the request. If the serving web cache server (108A) possesses a copy of the Internet object, it returns a copy of the Internet object to the web client (110A).
    Type: Grant
    Filed: June 25, 1999
    Date of Patent: July 29, 2003
    Assignee: Nortel Networks Limited
    Inventors: Anil Gurijala, Basudeb Dash
  • Patent number: 6597708
    Abstract: A network arrangement for transporting service (Servco) traffic between terminals via an asynchronous path comprises a servco access layer incorporating multimedia gateways for access by said terminals, an asynchronous network layer, a service layer incorporating adaptation layer switches each coupled to the network layer, and a transport layer providing a connection medium between the adaptation layer switches. The Servco traffic is carried in ATM minicells over the network layer. Delineation of the minicells is effected by searching the received ATM stream for a valid code word indicating the start of a minicell, and, for that minicell and subsequent minicells, determining length information so as to determine the start of each next minicell.
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventors: Roy Harold Mauger, Simon Daniel Brueckheimer
  • Patent number: 6597684
    Abstract: In a packet switching network, a distributed architecture provides efficient computation of routes in Quality of Service (QoS)-based routing scenarios. Using a client-server model, only designated route servers store and maintain a database containing the entire network topology, so that each network node is not required to store and maintain the network topology. Client nodes maintain a cache containing pre-computed routes so that they can often make routing decisions autonomously. A client contacts a designated route server only when the client cannot obtain from its local cache a route to a given destination that meets the performance requirements. A client cache may contain pre-computed routes with designated QoS profiles to all destinations or to a subset of destinations. Route servers may also contain caches, which may contain pre-computed routes to all destinations in the network with all QoS profiles, or may contain only a subset of such routes.
    Type: Grant
    Filed: December 24, 1997
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Ltd.
    Inventors: Neeraj Gulati, Zafar Ali, Saman A. Rabie, Ling-Yue Hung
  • Patent number: 6598232
    Abstract: A hybrid amplifier and regenerator (HAR) device is designed for use in a communications network for carrying downstream traffic in a forward frequency band and for carrying upstream traffic in a reverse frequency band spaced from the forward frequency band and below the forward frequency band. The hybrid amplifier and regenerator (HAR) device comprises an analog amplifier for amplifying the downstream traffic and a digital regenerator. The digital regenerator comprises mapping circuitry for mapping digital upstream traffic carried in at least one ramp band which is part of the reverse frequency band to digital upstream traffic carried in at least one express band which is also part of the reverse frequency band but spaced from the at least one ramp band, and an express band transmitter for transmitting digital upstream traffic from the mapping circuitry in the at least one express band.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventor: James Allan McAlear
  • Patent number: 6597704
    Abstract: An apparatus for translating a message (having message data) from a first transmission protocol to a second transmission protocol appends a length datum field to message data within a second protocol envelope that is used to transport the message in accord with the second transmission protocol. To that end, the apparatus first receives the message data from the first protocol, and then calculates the length of the received message data within the envelope. A length datum then is appended to the message data to produce a revised message. The length datum indicates the calculated length of the message data. Once produced, the revised message is directed to the second protocol for transmission in the second protocol.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventor: Ellis L. Wong
  • Patent number: 6597703
    Abstract: A system, device, and method for reducing multicast forwarding states in a multicast communication system maintains forwarding states in such a way that the non-default forwarding states have non-overlapping source address ranges. Each forwarding state is associated with a source address range encompassing one or more source addresses. When a non-default forwarding state is installed, the source address range for the forwarding state is selected so that the source address range does not overlap with the source address ranges of any other non-default forwarding states. The source address range for a particular forwarding state may be adjusted as new routes are learned or existing routes are changed or aged.
    Type: Grant
    Filed: November 29, 1999
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventors: Yunzhou Li, Shuching Shieh
  • Patent number: 6597255
    Abstract: A transmission system is provided for a power source to transfer power to equipment housed within a Faraday cage. The transmission system transfers energy along a non-conductive path yet remains in conductive contact with the Faraday cage. This prevents EMI disturbing electrical power provided within the Faraday cage and damaging equipment housed within the cage. The transmission system enables mains power to be transmitted to equipment housed within the Faraday cage without the need to provide conventional electric filters. The performance of the Faraday cage in shielding electromagnetic radiation is not compromised. Nor is the ability of the Faraday cage to shield electromagnetic radiation generated by communications equipment within the cage compromised.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventor: Brian C Turton
  • Patent number: 6598088
    Abstract: A method of processing a frame received at a networked device having a port switch and a general-purpose processor. The method can include receiving frame information at the port switch, determining at least one port for the frame, and directing the received frame information based on the determined port(s).
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Corporation
    Inventors: John C. Lynch, Marc Saunders, Brian Pick
  • Patent number: 6598033
    Abstract: A method of processing data such as alarms from a communications network, the network comprising a plurality of network entities, having predetermined states of operation, the method comprising the step of creating an object (88) associated with a given state of one of the entities, such as a fault state. The object comprises knowledge based reasoning capability (89) such as rules for determining whether the entity is in the given state, and the method further comprises the steps of: passing data about the network, such as alarms and events, to the object; and inferring whether the entity is in the given fault state using the rules. This enables faster correlation of alarms and simpler development and maintenance of the rules.
    Type: Grant
    Filed: July 14, 1997
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventors: Niall Ross, Anthony Richard Phillip White
  • Patent number: 6598189
    Abstract: A method of determining the actual transmission rate in a variable transmission rate communication system is provided, using error detection metrics. The received symbols are decoded assuming each possible rate, and then re-encoded to determine a symbol error rate for each possible rate. The possible transmission rates are then narrowed down using a simple measure of the likelihood of error, such as the CRC status determined for each rate. The symbol error rates are compared to either make a confident decision as to the actual transmission rate or to erase the frame. Rather than compare the values of the symbol error rates with predetermined thresholds, the method compares the differences between the symbol error rates for each possible rate with predetermined thresholds. This results in fewer erasures, even if the symbol error rates are low due to high signal to noise ratios.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventors: Wen Zhao, Robert Charles Elliott, Xin Jin
  • Patent number: 6597927
    Abstract: Disclosed is an apparatus for reducing the number of control signal channels required in a wireless communication system by using a umbrella control signal to initially communicate with an MS (mobile station) within the umbrella and to assign the MS to a traffic frequency corresponding to one of a plurality of antenna used to cover the area covered by said umbrella control signal. Logic is used in combination with measured relative signal strengths to determine the position of the MS relative to the reliable reception coverage area of each of the plurality of antennas before the assignment is made.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventors: Srinivas Eswara, Keith S. Wilson, Michael J. McCarthy
  • Patent number: 6597700
    Abstract: A distributed address database management technique involves maintaining an address database by each of a number of interconnected modules. Each module maintains a number of locally owned address entries and a number of remotely owned address entries in the address database. Each module monitors the status of its locally owned address entries, maintains the locally owned address entries based upon the status, and provides the status to the other interconnected modules. Each module maintains the remotely owned address entries based upon the status received from the other interconnected modules. When a module adds a locally owned address entry to its address database, the module notifies the other interconnected modules, which in turn add a corresponding remotely owned address entry to their respective address databases.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventors: Sandeep P. Golikeri, Da-Hai Ding, Nicholas Ilyadis, Timothy Cunningham, Manish Patel
  • Patent number: 6597662
    Abstract: Fairness is provided among network sessions contending for available bit rate (ABR) service in an asynchronous transfer mode network by determining congestion information on a per port basis. ABR cells are monitored to determine which rate information per outgoing port based on ABR cells leaving a switch. Using the ABR per port rate, the available capacity, and the input rate to output queues, a link congestion parameter (LCP) is determined. Resource Management (RM) cells traveling through the switch are monitored to determine whether the new LCP is lower than the explicit rate (ER) field in RM cell. If the new LCP is lower, the new LCP is stuffed into the RM cell. When the sender receives the LCP value, the sender output rate is adjusted based on the LCP. Because LCP is determined based on per port traffic flow, fairness is provided among session competing for available ABR capacity.
    Type: Grant
    Filed: May 13, 1998
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventors: Anurag Kumar, Santosh P. Abraham, Greg M. Bernstein, Jeffrey T. Gullicksen, Gurpreet S. Chhabra
  • Patent number: 6598200
    Abstract: Within a transmission channel in a frequency domain transmission medium, a plurality of non-contiguous channel portions are selected for data transmission. The selected channel portions are separated in frequency by unused channel portions. A transmitter generates a data frame of predetermined length for transmission, comprising a payload and an error detection portion. The frame length is equal to the length which would map for transmission into a symbol in the transmission channel if the entire channel were selected for transmission. The payload contains a header and a data portion, into which the transmitter inserts data bytes and a number of padding bytes. Block coding error correction is performed on the padded payload to generate error detection bytes to fill the error detection portion.
    Type: Grant
    Filed: June 2, 2000
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventors: John Christopher Greenwood, David Carotti
  • Patent number: 6597689
    Abstract: The Intelligent Multiservice Access System (IMAS) enables support for the next generation of virtual connections. Regardless of whether the communications lines coupled to the inputs and outputs of the IMAS are based on SVC, PVC, or a combination of PVC and SVC, the IMAS can support SVCs for a more flexible, timely, efficient, and manageable connection. In the more typical configuration, the loop side of the IMAS is PVC-based because the modems do not support SVC signaling, and the telecommunications backbone side is capable of supporting SVC signaling even though existing DSLAMs do not employ SVC signaling logic. With SVC support, the IMAS assists the ATM network in hand crafting an SVC-based connection almost immediately between end users when the originating end user wants to make a call to a destination end user, and tear down that virtual connection almost immediately when that call has completed.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventors: Manfred F. Chiu, Gregory C. Hill, Clifford James Buckley, Jens Arne Holten, Steven A. Eich, Michael E. Grimes, Yerrapalli R. Sudhakar, Anthony Peter Peck
  • Patent number: 6597774
    Abstract: The present invention provides an alert to a user after a predetermined amount of time has elapsed for a particular communication. The timing for the alert may be set by the user at the beginning of each call, or may be automatically configured during the initiation of a call or communication. Control of the alert and the respective timing preferably occurs at a local call control center, such as a central office switch in the public telephone system, or a mobile switching center in a wireless system. For voice communications, the alert is preferably audible. Alternatively, for data communications, the alert is configured to effect an audible, visual, or otherwise perceptible alert on the user's interface.
    Type: Grant
    Filed: June 13, 2000
    Date of Patent: July 22, 2003
    Assignee: Nortel Networks Limited
    Inventors: Teresa C. Jennings, Robert J. Green