Patents by Inventor Darwin A. Engwer

Darwin A. Engwer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8085727
    Abstract: According to one embodiment, a method involves receiving an incoming media access control (MAC) frame that includes a header, a frame body and an error detection field. Thereafter, an information element within the frame body is analyzed to determine whether to alter a mobility tunnel between a plurality of networking devices.
    Type: Grant
    Filed: December 23, 2004
    Date of Patent: December 27, 2011
    Assignee: Avaya Inc.
    Inventors: Haixiang He, Darwin A. Engwer
  • Patent number: 8041319
    Abstract: According to one embodiment, a method involves determining whether a wireless connection between a first access point and a wireless station has failed. If so, a partial scanning process is conducted only on a subset of communication channels over which data is transmitted by access points neighboring the first access point. The subset of communication channels, inclusive of zero, is determined by analysis of a scanning history database.
    Type: Grant
    Filed: December 23, 2004
    Date of Patent: October 18, 2011
    Assignee: Avaya Inc.
    Inventors: Haixiang He, Darwin A. Engwer
  • Patent number: 7643451
    Abstract: Fast transitions between access points (APs) in a wireless network may be accomplished when a mobile unit (MU) moves between the APs, by causing a first tunnel to be established between the APs, and causing a second tunnel to be established between the new AP and the MU. A data path having established security and quality of service parameters between the MU and the old AP may be extended through the tunnels, so that communication with the MU is not disrupted while transitioning between APs. Transition processing thus may be decoupled from movement of the MU, so that the MU may continue to receive access to data over the data path. Optionally, once the data path has been so extended, the MU and new AP may engage in authentication and other messaging to formally affect a handover of the data path to the new AP. The APs and MU may be configured to communicate according to the 802.11 protocol.
    Type: Grant
    Filed: October 14, 2005
    Date of Patent: January 5, 2010
    Assignee: Nortel Networks Limited
    Inventors: Haixiang He, Darwin Engwer
  • Publication number: 20090274094
    Abstract: To advertise capabilities of a wireless access point, the wireless access point communicates, to a mobile station, messages at plural levels of detail to advertise that the wireless access point supports a plurality of service networks. The messages at the plural levels of detail include a first message indicating that the wireless access point supports multiple service networks, and a second message containing information identifying the plurality of service networks.
    Type: Application
    Filed: December 29, 2008
    Publication date: November 5, 2009
    Applicant: NORTEL NETWORKS LIMITED
    Inventor: DARWIN A. ENGWER
  • Patent number: 7366103
    Abstract: A communication protocol that provides load balancing and/or test pattern information between devices is described. A first embodiment of the protocol provides such information via a data frame that is transmitted a definitive time after a special DTIM beacon is transmitted. This protocol provides full compliance with IEEE 802.11. The second embodiment of the protocol modifies the 802.11 beacon data structure with additional information elements.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: April 29, 2008
    Assignee: Nortel Networks Limited
    Inventors: Darwin A. Engwer, Jonathan M. Zweig
  • Patent number: 7339892
    Abstract: In a wireless network system having a wired backbone network, one or more access points (APs), and one or more wireless units (WUs), a technique wherein an AP automatically determines a factor indicative of the error(s) occurring in the transmissions of one or more data packets to associated WUs, and automatically adjust the fragmentation threshold in accordance with the transmission error factor. The AP adjusts the fragmentation threshold in a manner that the data throughput is increased. Since the AP automatically and periodically gauges the wireless medium for RF interference that can cause data transmission errors, the fragmentation threshold can be dynamically adjusted to respond to changes in the wireless medium, such as when a microwave oven is turned on, and/or when a Blue Tooth device is traversing the wireless medium, etc. This is much more effective than having a system administrator periodically gauge the wireless medium for the purpose of selecting the appropriate fragmentation threshold.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: March 4, 2008
    Assignee: Nortel Networks Limited
    Inventors: Darwin A. Engwer, Jonathan M. Zweig
  • Patent number: 7280495
    Abstract: A protocol for acknowledging receipt of a multicast or broadcast frame by a wireless unit is described. One embodiment, an Eavesdrop Unicast frame is created for use in a wireless network operated in accordance with IEEE 802.11. The Eavesdrop Unicast frame allows the targeted wireless unit to transmit acknowledgement (ACK) frame but is configured so that other wireless units can scan and obtain information therefrom. Another embodiment is similar in configuration to the Eavesdrop Unicast frame but is fully compliant with IEEE 802.11. Therein, a multicast or broadcast frame is transmitted but one wireless unit is configured to acknowledge receipt of the multicast or broadcast frame. The acknowledgement is accomplished through transmission of a data frame. Yet another embodiment is the transmission of broadcast or multicast frames into corresponding unicast frames.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: October 9, 2007
    Assignee: Nortel Networks Limited
    Inventors: Jonathan M. Zweig, Darwin A. Engwer
  • Patent number: 7154854
    Abstract: In a wireless network system comprising a wired backbone network, an access point, and one or more associated wireless unit data coupled to the access point by way of a wireless transmission medium, a method of enabling fragmentation of data packet above a fragmentation threshold in one or more wireless units, comprising transmitting a message to the one or more wireless unit having a first control data that causes the one or more wireless units to implement fragmentation threshold in transmitting data packets to the access point. The message is preferably a multicast data packet intended for the one or more associated wireless units. The message may further include a specified fragmentation to be used, and also another control signal for enabling request to send (RTS) and clear to send (CTS) transmission by the one or more wireless units.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: December 26, 2006
    Assignee: Nortel Networks Limited
    Inventors: Jonathan M. Zweig, Darwin A. Engwer
  • Patent number: 7082114
    Abstract: In a wireless network system having a wired backbone network with two or more sub-networks, each having one or more access points for communicating with wireless units via a wireless transmission medium, a system, apparatus and method for a wireless unit to determine whether a candidate access point is on a different sub-network than its current access point. If the wireless unit determines that the candidate access point is on a different sub-network, then the wireless unit releases its current network protocol address which was valid for the current sub-network, and obtains a new network protocol address valid for the new sub-network. This is accomplished by the candidate access point transmitting a multicast packet that includes the network protocol address of the access point and the subnet mask of the sub-network which the access point is on. By receiving this multicast packet, the wireless unit can determine if the candidate access point is on a different sub-network than its current sub-network.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: July 25, 2006
    Assignee: Nortel Networks Limited
    Inventors: Darwin A. Engwer, Jonathan M. Zweig, Paul McDaid
  • Publication number: 20060142004
    Abstract: According to one embodiment, a method involves determining whether a wireless connection between a first access point and a wireless station has failed. If so, a partial scanning process is conducted only on a subset of communication channels over which data is transmitted by access points neighboring the first access point. The subset of communication channels, inclusive of zero, is determined by analysis of a scanning history database.
    Type: Application
    Filed: December 23, 2004
    Publication date: June 29, 2006
    Inventors: Haixiang He, Darwin Engwer
  • Publication number: 20060140163
    Abstract: According to one embodiment, a method involves receiving an incoming media access control (MAC) frame that includes a header, a frame body and an error detection field. Thereafter, an information element within the frame body is analyzed to determine whether to alter a mobility tunnel between a plurality of networking devices.
    Type: Application
    Filed: December 23, 2004
    Publication date: June 29, 2006
    Inventors: Haixiang He, Darwin Engwer
  • Patent number: 7039190
    Abstract: In one embodiment, an authentication method features the generation of an initialization vector at a first electronic device and the determination at the first electronic device whether the initialization vector falls within a first group of initialization vectors. The first group includes a plurality of initialization vectors solely used in connection with an authentication sequence. Information is encrypted using in part the initialization vector for return to a second electronic device if the initialization vector falls within the first group.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: May 2, 2006
    Assignee: Nortel Networks Limited
    Inventors: Darwin A. Engwer, Jonathan M. Zweig
  • Publication number: 20060083201
    Abstract: Fast transitions between access points (APs) in a wireless network may be accomplished when a mobile unit (MU) moves between the APs, by causing a first tunnel to be established between the APs, and causing a second tunnel to be established between the new AP and the MU. A data path having established security and quality of service parameters between the MU and the old AP may be extended through the tunnels, so that communication with the MU is not disrupted while transitioning between APs. Transition processing thus may be decoupled from movement of the MU, so that the MU may continue to receive access to data over the data path. Optionally, once the data path has been so extended, the MU and new AP may engage in authentication and other messaging to formally affect a handover of the data path to the new AP. The APs and MU may be configured to communicate according to the 802.11 protocol.
    Type: Application
    Filed: October 14, 2005
    Publication date: April 20, 2006
    Applicant: Nortel Networks Limited
    Inventors: Haixiang He, Darwin Engwer
  • Patent number: 6947483
    Abstract: According to one aspect of the present invention, a method is provided in which an access point and a mobile unit associated with the access point may optionally transmit compressed data to each other if the receiving unit is capable of handling data compression. In one embodiment, the access point communicates to one or more mobile units to inform the one or more mobile units of the access point's compression capabilities. A mobile unit which is associated with the access point, upon being informed that the access point is capable of handling data compression, may optionally compress data prior to transmitting the data to the access point. The access point, upon receiving compressed data from the mobile unit which indicates to the access point that the mobile unit is capable of handling data compression, may optionally compress data prior to transmitting the data to the mobile unit.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: September 20, 2005
    Assignee: Nortel Networks Limited
    Inventor: Darwin A. Engwer
  • Publication number: 20030193895
    Abstract: A communication protocol that provides load balancing and/or test pattern information between devices is described. A first embodiment of the protocol provides such information via a data frame that is transmitted a definitive time after a special DTIM beacon is transmitted. This protocol provides full compliance with IEEE 802.11. The second embodiment of the protocol modifies the 802.11 beacon data structure with additional information elements.
    Type: Application
    Filed: December 28, 2000
    Publication date: October 16, 2003
    Inventors: Darwin A. Engwer, Jonathan M. Zweig
  • Publication number: 20020085631
    Abstract: According to one aspect of the present invention, a method is provided in which an access point and a mobile unit associated with the access point may optionally transmit compressed data to each other if the receiving unit is capable of handling data compression. In one embodiment, the access point communicates to one or more mobile units to inform the one or more mobile units of the access point's compression capabilities. A mobile unit which is associated with the access point, upon being informed that the access point is capable of handling data compression, may optionally compress data prior to transmitting the data to the access point. The access point, upon receiving compressed data from the mobile unit which indicates to the access point that the mobile unit is capable of handling data compression, may optionally compress data prior to transmitting the data to the mobile unit.
    Type: Application
    Filed: December 28, 2000
    Publication date: July 4, 2002
    Inventor: Darwin A. Engwer
  • Patent number: 5987062
    Abstract: A wireless local area network allows roaming of a mobile unit to allow it to serially associate with a number of access points of the network fixed backbone. This roaming is supported by an improved measurement of communications link quality, which includes calculating a mean error free length of a test pattern broadcast by each access point and received by a mobile unit. The test pattern is a digital data message. Thus an accurate measurement of link quality is provided which allows a mobile unit to determine whether it should change its association to another access point having improved communications link quality. Further, a load balancing process is provided to balance the communications load amongst a variety of access points, by allowing mobile units also to switch their association with access points in accordance with a current total data rate at any given access point and also considering the number of currently high data rate mobile units associated with a particular access point at any one time.
    Type: Grant
    Filed: December 15, 1995
    Date of Patent: November 16, 1999
    Assignee: Netwave Technologies, Inc.
    Inventors: Darwin A. Engwer, Ken Clements, Jonathan M. Zweig, Daniel S. Perrin