Patents by Inventor Brian Donald Hart

Brian Donald Hart 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: 9658315
    Abstract: In an example embodiment, there is disclosed herein, an apparatus comprising an interface and location determination logic coupled with the interface. The location determination logic receives data representative of measured signal strengths for a wireless device from a plurality of receiving devices at known locations via the interface. The location determination logic determines an estimated location based on the measured signal strengths and a first transmit power for the wireless device. The location determination logic determines a revised transmit power for the wireless device based on the measured signal strengths from the plurality of devices at known locations and the estimated location. The location determination logic determines a revised estimated location based on the measured signal strengths and the revised transmit power for the wireless device.
    Type: Grant
    Filed: November 11, 2013
    Date of Patent: May 23, 2017
    Assignee: Cisco Technology, Inc.
    Inventors: Santosh Pandey, Brian Donald Hart, Ilya Khasin
  • Patent number: 9572026
    Abstract: In an example embodiment, a wireless device is operable to advertise a policy on the inclusion of the wireless device in a radio frequency map. For example, the wireless device may transmit a signal comprising a field in an extended capabilities information that indicates whether mapping of the wireless device is permissible. As another example, the wireless device may perform certain actions, such as changing media access control address, changing transmit power, and/or vary response times to prevent accurate mapping of the location of the wireless device.
    Type: Grant
    Filed: October 16, 2012
    Date of Patent: February 14, 2017
    Assignee: Cisco Technology, Inc.
    Inventors: Brian Donald Hart, Santosh Pandey, Kayshav Dattatri
  • Patent number: 9313786
    Abstract: In an example embodiment described herein is an apparatus comprising a wireless transceiver and channel selection logic coupled to the wireless transceiver and operable to select an operating frequency for the wireless transceiver. The channel selection logic is configured to reserve a dedicated channel having a special identifier. The channel selection logic is configured to have the wireless transceiver advertise the dedicated service on a normal operating frequency. The channel selection logic is responsive to receiving a request from a wireless device via the wireless transceiver on the normal operating frequency to use the dedicated channel to switch to the dedicated channel and establish communications with the wireless device on the dedicated channel.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: April 12, 2016
    Assignee: Cisco Technology, Inc.
    Inventors: Neil Robert Diener, Abhijit Kumar Choudhury, Brian Donald Hart, David S. Stephenson
  • Patent number: 9137663
    Abstract: In one embodiment, a method includes identifying, responsive to a triggering event, one or more radio frequency (RF) firewall transceivers that neighbor a data wireless access point to which a given wireless client is communicating; configuring one or more of the identified neighboring RF firewall transceivers to detect RF frames transmitted by the wireless client; causing the data wireless access point to transmit one or more wireless messages operative to cause the wireless client to transmit RF frames; collecting RF signal data corresponding to the RF frames transduced by one or more of the identified neighboring RF firewall transceivers; transmitting the collected RF signal data to a location system; receiving from the location system an indication of the location of the wireless client; and applying one or more network access policies based on the indication of the location.
    Type: Grant
    Filed: November 2, 2006
    Date of Patent: September 15, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Allan Thomson, Brian Donald Hart, Mark Paul Yankowski, Christine Andiazabal, Timothy S. Olson
  • Patent number: 9065580
    Abstract: In an example embodiment, a method for synchronizing clocks between a plurality of clocked devices where one of the plurality of clocked devices is not directly synchronized with another of the plurality of clocked devices. Clock offset and a clock drift between a first clock associated with a first device and a second clock associated with a second is directly determined based on signals exchanged between the first and second devices. Clock offset and clock drift between the second clock and a third clock associated with a third device is directly determined based on signals exchanged between the second and third devices. A clock offset and clock drift between the first clock and third clock is determined based on a difference between the clock offset and drift between the first and second clocks and the clock offset and drift between the second and third clocks.
    Type: Grant
    Filed: July 18, 2012
    Date of Patent: June 23, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Matthew Aaron Silverman, Paul Jeffrey Stager, Brian Donald Hart
  • Patent number: 9055395
    Abstract: In one embodiment, an apparatus includes a receiver configured for receiving a response message from a tracked device in a wireless network, the response message transmitted in response to a provoking message having an identifier of the tracked device in a transmitter address field, and a processor for measuring at least one location related parameter, extracting the identifier of the tracked device from the response message and identifying the response message as a location tracking message based on information in the response message. A field of the response message includes the identifier of the tracked device copied from the provoking message and the transmitter address is not provided in another field of the response message.
    Type: Grant
    Filed: November 12, 2009
    Date of Patent: June 9, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Brian Donald Hart, Allan Thomson, Visshwanth Reddy
  • Patent number: 8971213
    Abstract: In one embodiment, a method includes generating for a client device associated with an access point, a partial association identifier based on an association identifier assigned to the client device and a hash of a basic service set identifier the client device is associated with, and transmitting a packet to the client device, the packet comprising the partial association identifier. The partial association identifier indicates that the packet is intended for the client device. An apparatus is also disclosed.
    Type: Grant
    Filed: October 20, 2011
    Date of Patent: March 3, 2015
    Assignee: Cisco Technology, Inc.
    Inventor: Brian Donald Hart
  • Publication number: 20140327579
    Abstract: In one embodiment, an apparatus includes a plurality of antennas, a receiver in communication with said plurality of antennas for receiving one or more packets in a block based modulation environment, a switch interposed between a portion of the antennas and the receiver for switching between the antennas, and a processor for calculating angle of arrival for use in identifying a location of a mobile device transmitting the one or more packets.
    Type: Application
    Filed: May 3, 2013
    Publication date: November 6, 2014
    Applicant: CISCO TECHNOLOGY, INC.
    Inventors: Brian Donald Hart, Paul J. Stager, Santosh Pandey, David Kloper, Dan Lyons, Matthew A. Silverman
  • Patent number: 8817756
    Abstract: Allocation schemes are provided for one or more portions of time during a data transmission time interval for contention by personal coordination points, access points and client devices to perform transmit sector sweep operations. In addition, a personal coordination point determines whether the set of channels universally agreed to be free by nearby synchronization access points is empty and selects any channel in the frequency band to initiate a Basic Service Set or continue operation of an existing Basic Service Set if it is determined that no channel in the frequency band is free among the channels that are universally agreed to be free.
    Type: Grant
    Filed: January 11, 2012
    Date of Patent: August 26, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Brian Donald Hart, Genyuan Wang, Hang Jin
  • Patent number: 8811189
    Abstract: Described in an example embodiment herein is a technique for generating a heat map representative of a radio frequency environment based on data representative of antenna pattern, antenna orientation, access point height and a path loss model. In particular embodiments, the base heat map can be corrected based on neighbor access point (AP) signal strength measurements, such as received signal strength indications (RSSIs) that are added over a base heat map. The neighbor RSSIs may be adjusted to a point underneath the AP.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: August 19, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Santosh Pandey, Brian Donald Hart, Deepak Badri
  • Patent number: 8797881
    Abstract: In accordance with an example embodiment, there is disclosed herein a coexistence mechanism for multiple channels. A plurality of channels are monitored to determine which channels are available for communications. Upon receiving a request to establish communications on a channel set within the plurality of channels, a response is sent to the request on at least one in the channel set. The response comprises data representative of which channels from the channel set are available for communications. Optionally, the response may include data indicating how long the unavailable channels will be occupied.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: August 5, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Brian Donald Hart, Raghuram Rangarajan, Ahmadreza Hedayat
  • Patent number: 8781040
    Abstract: A mid-packet detection technique is provided that detects a packet with periodic repetitions of a fixed duration at a point in time of the packet other than a start-of-packet pattern, e.g., a preamble, associated with the packet. The process performs packet detection without detecting a preamble and does not require carrier frequency recovery, timing recovery (synchronization) or channel estimation. In one embodiment, a doubly differential matched filter autocorrelation of the received signal is computed and used as a metric for packet detection when the preamble is not observed or to complement preamble detection. The metric is compared to a threshold to indicate detection of a packet.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: July 15, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Raghuram Rangarajan, Brian Donald Hart, Paul J. Stager
  • Patent number: 8730960
    Abstract: Described herein are techniques that provide for the transmission of a multicast stream that can resend frames that were not received using the partial state block acknowledgement mechanism. In an example embodiment, an access point reserves a channel for a transmission opportunity of a sufficient length to allow the sending of multicast data, block acknowledgement request, and receipt of a block acknowledgement. Optionally, the transmission opportunity may be of sufficient length to enable packets that re resent to be sent during the transmission opportunity, thereby preventing other stations on the channel from gaining control of the channel. Alternatively the access point may employ an appropriate backoff between TXOPs to AP prevent (T)DLS traffic to the recipients of the multicast stream. The access point does not send any frames from other queues during the transmission opportunity.
    Type: Grant
    Filed: October 25, 2011
    Date of Patent: May 20, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Brian Donald Hart, Santosh Pandey, Rohit Suri
  • Patent number: 8718172
    Abstract: Techniques are provided for generating a precoding matrix for a multi-user multiple-input multiple-output wireless communication system. A first wireless communication device is provided that has a plurality of antennas from which multiple spatial streams are to be simultaneously transmitted to a plurality of second wireless communication devices. A channel matrix is computed between the antennas of the first device and the antennas of each of the second wireless communication devices to produce a plurality of client-specific channel matrices. A singular value decomposition is computed of each client-specific channel matrices. A number of strongest singular values and their corresponding singular vectors are stored from the singular decomposition of each of the client-specific channel matrices. From each client-specific channel matrix, a principal component-like single-client channel matrix is computed.
    Type: Grant
    Filed: April 30, 2012
    Date of Patent: May 6, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Brian Donald Hart, Genyuan Wang, Ahmadreza Hedayat, Paul J. Stager
  • Publication number: 20140105395
    Abstract: In an example embodiment, a wireless device is operable to advertise a policy on the inclusion of the wireless device in a radio frequency map. For example, the wireless device map transmit a signal comprising a field in an extended capabilities information that indicates whether mapping of the wireless device is permissible. As another example, the wireless device may perform certain actions, such as changing media access control address, changing transmit power, and/or vary response times to prevent accurate mapping of the location of the wireless device.
    Type: Application
    Filed: October 16, 2012
    Publication date: April 17, 2014
    Applicant: Cisco Technology, Inc.
    Inventors: Brian Donald HART, Santosh PANDEY, Kayshav DATTATRI
  • Publication number: 20140062789
    Abstract: In an example embodiment, there is disclosed herein, an apparatus comprising an interface and location determination logic coupled with the interface. The location determination logic receives data representative of measured signal strengths for a wireless device from a plurality of receiving devices at known locations via the interface. The location determination logic determines an estimated location based on the measured signal strengths and a first transmit power for the wireless device. The location determination logic determines a revised transmit power for the wireless device based on the measured signal strengths from the plurality of devices at known locations and the estimated location. The location determination logic determines a revised estimated location based on the measured signal strengths and the revised transmit power for the wireless device.
    Type: Application
    Filed: November 11, 2013
    Publication date: March 6, 2014
    Applicant: Cisco Technology, Inc.
    Inventors: Santosh Pandey, Brian Donald Hart, Ilya Khasin
  • Publication number: 20140052508
    Abstract: In an example embodiment, unauthorized wireless services and advertisements can be detected by access points via active or passive scanning. Unauthorized, or rogue, service advertisements are reported to the venue owner along with contextual information for further mitigation.
    Type: Application
    Filed: August 14, 2012
    Publication date: February 20, 2014
    Inventors: Santosh PANDEY, Brian Donald Hart, Andrew Myles
  • Patent number: 8582541
    Abstract: A technique is provided to enable a ranging-enhanced communication device that operates according to a legacy communication protocol to transmit a ranging waveform that is not defined in, or part of, the rules of the legacy communication protocol. In one embodiment, a ranging-enhanced communication device that is to transmit the ranging waveform generates information representing a time interval within which to wirelessly transmit a ranging waveform that is not defined by a legacy communication protocol. This information is encoded into a field of a frame that is formatted according to the legacy communication protocol to protect the time interval from transmissions by legacy communication devices that operate according to the legacy communication protocol. The ranging-enhanced communication device transmits the frame and transmits the ranging waveform during the time interval following the frame.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: November 12, 2013
    Assignee: Cisco Technology, Inc.
    Inventor: Brian Donald Hart
  • Publication number: 20130287131
    Abstract: Techniques are provided for generating a precoding matrix for a multi-user multiple-input multiple-output wireless communication system. A first wireless communication device is provided that has a plurality of antennas from which multiple spatial streams are to be simultaneously transmitted to a plurality of second wireless communication devices. A channel matrix is computed between the antennas of the first device and the antennas of each of the second wireless communication devices to produce a plurality of client-specific channel matrices. A singular value decomposition is computed of each client-specific channel matrices. A number of strongest singular values and their corresponding singular vectors are stored from the singular decomposition of each of the client-specific channel matrices. From each client-specific channel matrix, a principal component-like single-client channel matrix is computed.
    Type: Application
    Filed: April 30, 2012
    Publication date: October 31, 2013
    Applicant: CISCO TECHNOLOGY, INC.
    Inventors: Brian Donald Hart, Genyuan Wang, Ahmadreza Hedayat, Paul J. Stager
  • Publication number: 20130279349
    Abstract: Described in an example embodiment herein is a technique for generating a heat map representative of a radio frequency environment based on data representative of antenna pattern, antenna orientation, access point height and a path loss model. In particular embodiments, the base heat map can be corrected based on neighbor access point (AP) signal strength measurements, such as received signal strength indications (RSSIs) that are added over a base heat map. The neighbor RSSIs may be adjusted to a point underneath the AP.
    Type: Application
    Filed: April 23, 2012
    Publication date: October 24, 2013
    Inventors: Santosh PANDEY, Brian Donald Hart, Deepak Badri