Patents by Inventor Bretton Douglas

Bretton Douglas 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: 9236928
    Abstract: An apparatus and method for operating a Multiple Input Multiple Output (MIMO)-capable subscriber node are disclosed. In one embodiment, an apparatus includes a MIMO-capable physical layer transceiver and a Medium Access Control (MAC) layer block that measures a received transmission to determine channel conditions. Upon receiving a transmission wherein said channel conditions meet specified conditions, the MAC layer block transmits a message to an access point indicating that the apparatus wants to switch between a non-MIMO mode and a MIMO mode, and upon receiving an acknowledgement, the MAC layer block switches between the non-MIMO mode and the MIMO mode. An apparatus for operating an access node is also disclosed.
    Type: Grant
    Filed: November 18, 2013
    Date of Patent: January 12, 2016
    Assignee: Cisco Technology, Inc.
    Inventors: Ozgur Gurbuz, David Pignatelli, David Stephenson, Eldad Perahia, Bretton Douglas, Ender Ayanoglu
  • Patent number: 9131029
    Abstract: Multiple Input Multiple Output (MIMO) technology in conjunction with the IEEE 802.11 standard enables simultaneous communication of data packets to or from multiple users in the same frequency. Spatial divisional multiple access (SDMA) is thus provided. In this way, system capacity can be increased to an extent that depends on available antenna resources and the multipath characteristics of the communication channel. Doubling or quadrupling of network throughput can be achieved.
    Type: Grant
    Filed: April 7, 2014
    Date of Patent: September 8, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Eldad Perahia, Bretton Douglas, David Pignatelli, David Stephenson
  • Patent number: 9054934
    Abstract: A specialized preamble is provided to facilitate matrix channel estimation of a MIMO channel. In a particular implementation, a channel training preamble provided by the IEEE 802.11a standard is modified to facilitate MIMO channel estimation.
    Type: Grant
    Filed: December 19, 2013
    Date of Patent: June 9, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Eldad Perahia, Bretton Douglas, David Pignatelli
  • Patent number: 8737328
    Abstract: Multiple Input Multiple Output (MIMO) technology in conjunction with the IEEE 802.11 standard enables simultaneous communication of data packets to or from multiple users in the same frequency. Spatial divisional multiple access (SDMA) is thus provided. In this way, system capacity can be increased to an extent that depends on available antenna resources and the multipath characteristics of the communication channel. Doubling or quadrupling of network throughput can be achieved.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: May 27, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Eldad Perahia, Bretton Douglas, David Pignatelli, David Stephenson
  • Patent number: 8693450
    Abstract: In one embodiment, different physical layer standards are segregated into different frequency channels. In one implementation, 802.11b traffic and 802.11g traffic are segregated into different frequency channels. A network management tool allows the user to specify channels to either, e.g., 802.11b-only, 802.11g-only, 802.11b preferred and 802.11g discouraged, or 802.11g preferred and 802.11b discouraged. Access points are given the capability of preventing or discouraging client traffic of either given type.
    Type: Grant
    Filed: June 4, 2010
    Date of Patent: April 8, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Tania Sung-Yi Chen, Bretton Douglas, Arnold Bilstad
  • Patent number: 8644430
    Abstract: A specialized preamble is provided to facilitate matrix channel estimation of a MIMO channel. In a particular implementation, a channel training preamble provided by the IEEE 802.11a standard is modified to facilitate MIMO channel estimation.
    Type: Grant
    Filed: October 30, 2012
    Date of Patent: February 4, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Eldad Perahia, Bretton Douglas, David Pignatelli
  • Patent number: 8625507
    Abstract: An apparatus and method for operating a Multiple Input Multiple Output (MIMO)-capable subscriber node are disclosed. In one embodiment, an apparatus includes a MIMO-capable physical layer transceiver and a Medium Access Control (MAC) layer block that measures a received transmission to determine channel conditions. Upon receiving a transmission wherein said channel conditions meet specified conditions, the MAC layer block transmits a message to an access point indicating that the apparatus wants to switch between a non-MIMO mode and a MIMO mode, and upon receiving an acknowledgement, the MAC layer block switches between the non-MIMO mode and the MIMO mode. An apparatus for operating an access node is also disclosed.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: January 7, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Ozgur Gurbuz, David Pignatelli, David Stephenson, Eldad Perahia, Bretton Douglas, Ender Ayanoglu
  • Patent number: 8374105
    Abstract: A specialized preamble is provided to facilitate matrix channel estimation of a MIMO channel. In a particular implementation, a channel training preamble provided by the IEEE 802.11a standard is modified to facilitate MIMO channel estimation.
    Type: Grant
    Filed: January 28, 2008
    Date of Patent: February 12, 2013
    Assignee: Cisco Technology, Inc.
    Inventors: Eldad Perahia, Bretton Douglas, David Pignatelli
  • Patent number: 8369657
    Abstract: Techniques are provided for selecting channels for a wider bandwidth operation mode of a wireless network, such as wireless network that operates in accordance with the IEEE 802.11n amendment. Alignments of so-called primary and secondary channels are selected to mitigate interference. Interfering sources, such as other transceivers or external interferers, or the energy from their transmissions, are identified and channels are selected. The selected channels are analyzed to determine whether primary-secondary channel assignments for the selected channels are feasible.
    Type: Grant
    Filed: March 6, 2012
    Date of Patent: February 5, 2013
    Assignee: Cisco Technology, Inc.
    Inventors: Douglas Chan, Brian Donald Hart, Bretton Douglas
  • Patent number: 8331977
    Abstract: A search algorithm to find a globally optimal radio plan for a wireless network, including assignments of frequency and transmission power to multiple access points. Two different evaluation metrics are used in order to provide an optimal solution in a reasonable time period. Frequency searches are performed using a special rapid evaluation metric. Transmission powers are selected using a more refined metric that estimates data throughput. The search results are deterministic and execution time is also substantially deterministic.
    Type: Grant
    Filed: February 7, 2012
    Date of Patent: December 11, 2012
    Assignee: Cisco Technology, Inc.
    Inventors: Bretton Douglas, Timothy Olson
  • Publication number: 20120163331
    Abstract: Techniques are provided for selecting channels for a wider bandwidth operation mode of a wireless network, such as wireless network that operates in accordance with the IEEE 802.11n amendment. Alignments of so-called primary and secondary channels are selected to mitigate interference. Interfering sources, such as other transceivers or external interferers, or the energy from their transmissions, are identified and channels are selected. The selected channels are analyzed to determine whether primary-secondary channel assignments for the selected channels are feasible.
    Type: Application
    Filed: March 6, 2012
    Publication date: June 28, 2012
    Applicant: CISCO TECHNOLOGY, INC.
    Inventors: Douglas Chan, Brian Donald Hart, Bretton Douglas
  • Publication number: 20120134290
    Abstract: A search algorithm to find a globally optimal radio plan for a wireless network, including assignments of frequency and transmission power to multiple access points. Two different evaluation metrics are used in order to provide an optimal solution in a reasonable time period. Frequency searches are performed using a special rapid evaluation metric. Transmission powers are selected using a more refined metric that estimates data throughput. The search results are deterministic and execution time is also substantially deterministic.
    Type: Application
    Filed: February 7, 2012
    Publication date: May 31, 2012
    Applicant: CISCO TECHNOLOGY, INC.
    Inventors: Bretton Douglas, Timothy Olson
  • Patent number: 8155482
    Abstract: Techniques are provided for selecting channels for a wider bandwidth operation mode of a wireless network, such as wireless network that operates in accordance with the IEEE 802.11n amendment. Alignments of so-called primary and secondary channels are selected to mitigate interference. Interfering sources, such as other transceivers or external interferers, or the energy from their transmissions, are identified and channels are selected. The selected channels are analyzed to determine whether primary-secondary channel assignments for the selected channels are feasible.
    Type: Grant
    Filed: July 1, 2008
    Date of Patent: April 10, 2012
    Assignee: Cisco Technology, Inc.
    Inventors: Douglas Chan, Brian Donald Hart, Bretton Douglas
  • Patent number: 8140104
    Abstract: A search algorithm to find a globally optimal radio plan for a wireless network, including assignments of frequency and transmission power to multiple access points. Two different evaluation metrics are used in order to provide an optimal solution in a reasonable time period. Frequency searches are performed using a special rapid evaluation metric. Transmission powers are selected using a more refined metric that estimates data throughput. The search results are deterministic and execution time is also substantially deterministic.
    Type: Grant
    Filed: January 27, 2009
    Date of Patent: March 20, 2012
    Assignee: Cisco Technology, Inc.
    Inventors: Bretton Douglas, Timothy Olson
  • Patent number: 7995525
    Abstract: Multiple Input Multiple Output (MIMO) technology in conjunction with the IEEE 802.11 standard enables simultaneous communication of data packets to or from multiple users in the same frequency. Spatial divisional multiple access (SDMA) is thus provided. In this way, system capacity can be increased to an extent that depends on available antenna resources and the multipath characteristics of the communication channel. Doubling or quadrupling of network throughput can be achieved.
    Type: Grant
    Filed: January 28, 2008
    Date of Patent: August 9, 2011
    Assignee: Cisco Technology, Inc.
    Inventors: Eldad Perahia, Bretton Douglas, David Pignatelli, David Stephenson
  • Patent number: 7929412
    Abstract: An apparatus and method for operating a Multiple Input Multiple Output (MIMO)-capable subscriber node are disclosed. In one embodiment, an apparatus includes a MIMO-capable physical layer transceiver and a Medium Access Control (MAC) layer block that measures a received transmission to determine channel conditions. Upon receiving a transmission wherein said channel conditions meet specified conditions, the MAC layer block requests an access point for permission to switch between a non-MIMO mode and a MIMO mode, and upon receiving permission, the MAC layer block switches between the non-MIMO mode and the MIMO mode. An apparatus for operating an access node is also disclosed.
    Type: Grant
    Filed: October 16, 2007
    Date of Patent: April 19, 2011
    Assignee: Cisco Technology, Inc.
    Inventors: Ozgur Gurbuz, David Pignatelli, David Stephenson, Eldad Perahia, Bretton Douglas, Ender Ayanoglu
  • Patent number: 7813385
    Abstract: Systems and methods for adapting IEEE 802.11 wireless communications for environments involving long propagation delays. Improved system throughput and stability are provided. Propagation delays are measured systematically and used to adjust contention timing boundaries and a common time slot duration. This reduces the probability of collision in the CSMA/CA mode of the IEEE 802.11 standard. One particular application is a point-to-multipoint campus bridge network.
    Type: Grant
    Filed: March 1, 2004
    Date of Patent: October 12, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: Sang Kyoon Hyun, Bretton Douglas
  • Publication number: 20100246551
    Abstract: In one embodiment, different physical layer standards are segregated into different frequency channels. In one implementation, 802.11b traffic and 802.11g traffic are segregated into different frequency channels. A network management tool allows the user to specify channels to either, e.g., 802.11b-only, 802.11g-only, 802.11b preferred and 802.11g discouraged, or 802.11g preferred and 802.11b discouraged. Access points are given the capability of preventing or discouraging client traffic of either given type.
    Type: Application
    Filed: June 4, 2010
    Publication date: September 30, 2010
    Applicant: Cisco Technology, Inc.
    Inventors: Tania Sung-Yi Chen, Bretton Douglas, Arnold Bilstad
  • Patent number: 7760692
    Abstract: Significant improvements in throughput of networks employing disparate physical layer standards are provided. Different physical layer standards are segregated into different frequency channels. In one implementation, 802.11b traffic and 802.11g traffic are segregated into different frequency channels. A network management tool allows the user to specify channels to either, e.g., 802.11b-only, 802.11g-only, 802.11b preferred and 802.11g discouraged, or 802.11g preferred and 802.11b discouraged. Access points are given the capability of preventing or discouraging client traffic of either given type.
    Type: Grant
    Filed: May 3, 2004
    Date of Patent: July 20, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: Tania Sung-Yi Chen, Bretton Douglas, Arnold Bilstad
  • Patent number: 7688762
    Abstract: In an example embodiment, a number of contending nodes and colliding nodes for a plurality of links of a network is determined. The capacity of each of the plurality of links is determined. A sum of the traffic demand of each of the plurality of links divided the throughput of each of the plurality of links is used to form a cost function for the network. One, or more, of a group consisting of a plurality of frequency assignments, a plurality of transmit powers, and a plurality of clear channel assessment (CCA) values is searched to obtain a global minimum for the cost function. The frequency assignments, transmit powers, and/or CCA values providing the global minimum for the cost function are selected.
    Type: Grant
    Filed: March 21, 2007
    Date of Patent: March 30, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: Bretton Douglas, Brian Hart