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).
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Cross-layer design techniques for interference-aware routing configuration in wireless mesh networks
Patent number: 7936681Abstract: Methods, apparatuses and systems directed to facilitating increased throughput in wireless mesh networks. Generally, according to one implementation of the present invention, routing nodes in a wireless mesh network combine metrics corresponding to the link and network layers to select a route to a root node in the wireless mesh network. In one implementation, for each neighbor, a given routing node computes a routing metric, which is based on the computed route cost and hop count, and selects a preferred neighbor as the parent routing node based on the best routing metric.Type: GrantFiled: March 6, 2006Date of Patent: May 3, 2011Assignee: Cisco Technology, Inc.Inventors: Xiaohong Gong, Brian Donald Hart, Bretton Lee Douglas -
Patent number: 7916708Abstract: Methods, apparatuses and systems directed to partitioning access points into two or more network access layers, such as overlay and underlay network access layers. According to one implementation of the present invention, a wireless network management system partitions a set of wireless access points into an overlay network for low-functionality clients and an underlay network for high-functionality clients. As described in further detail below, each of the overlay and underlay networks provides a class of network service, where each class of network service differs relative to at least one attribute (e.g., type of 802.11 access, data rates, High-Density, Quality-of-Service, encryption, compression, etc.). For didactic purposes, the overlay network is also referred to as the overlay network service layer (NSL) and the underlay network is referred to as the underlay NSL.Type: GrantFiled: July 13, 2009Date of Patent: March 29, 2011Assignee: Cisco Technology, Inc.Inventor: Brian Donald Hart
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Patent number: 7904092Abstract: In one embodiment, a method for adjusting a radio-frequency coverage map. The method includes receiving calibration data comprising observed received signal strength values at one or more calibration points corresponding to a radio frequency transmitter, and identifying an applicable coverage map, where the coverage map provides, for the radio frequency transmitter, estimated received signal strength values at one or more locations. The method also includes determining one or more offset values at the one or more calibration points, where an offset value is based on a difference between an observed received signal strength value and an estimated received signal strength value at a given calibration point. The method also includes adjusting one or more estimated received signal strength values at one or more location bins of the coverage map based on a distance from the one or more calibration points and the one or more offset values.Type: GrantFiled: January 4, 2007Date of Patent: March 8, 2011Assignee: Cisco Technology, Inc.Inventors: Brian Donald Hart, Bretton Lee Douglas
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Patent number: 7894412Abstract: An apparatus configured to acquire received signal strength intensities (RSSIs) for a wireless device from a plurality of access points (APs) located on a plurality floors. The apparatus is configured to determine which floor the wireless device is on by analyzing the RSSIs. In an example embodiment, the RSSIs are adjusted, and the adjusted RSSIs for each floor are summed. The floor with highest sum of adjusted RSSIs is determined to be the floor the wireless device is on. In an example embodiment, the floor that the wireless device is on is determined by calculating the probability that the wireless device is within the cell of each AP on the network, and combining the probabilities for each floor. Known RSSIs between APs can be employed for comparing measured RSSIs with the known RSSIs to determine the probability that the wireless device is within the cell of each AP.Type: GrantFiled: September 7, 2007Date of Patent: February 22, 2011Assignee: Cisco Technology, Inc.Inventors: Brian Donald Hart, Anto Jacob, Nirmala Nott Venkataramani, Emilio Maldonado
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DYNAMICALLY DEDICATED WIRELESS LOCAL AREA NETWORK SERVICE FOR HIGH DEFINITION VIDEO TELECONFERENCING
Publication number: 20110026441Abstract: 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: ApplicationFiled: July 29, 2009Publication date: February 3, 2011Inventors: Neil Robert DIENER, Abhijit Kumar Choudhury, Brian Donald Hart, David S. Stephenson -
Patent number: 7843817Abstract: A congestion control system. In particular implementations, a method includes receiving packets into one or more queues and monitoring the one or more queues for congestion. The method also includes, if a number of packets in the one or more queues exceeds a first threshold, determining a congestion control mode. The method also includes generating a congestion control message indicating the congestion control mode and transmitting the congestion control message to one or more neighboring mesh nodes.Type: GrantFiled: March 11, 2008Date of Patent: November 30, 2010Assignee: Cisco Technology, Inc.Inventors: Xiaohong Gong, Robert B. O'Hara, Jr., Brian Donald Hart, Johannes Petrus Kruys
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Patent number: 7835749Abstract: In one embodiment, a method includes receiving calibration data, computing one or more attributes of a pathloss model based on the calibration data, computing estimated locations using the received signal strength values of the calibration data points, associating location errors with the one or more calibration data points, and computing a location quality within a region based on the associated location errors.Type: GrantFiled: October 3, 2006Date of Patent: November 16, 2010Assignee: Cisco Technology, Inc.Inventors: Brian Donald Hart, Milind Paranjpe, Emilio Maldonado, Allan Thomson, Bhautik Doshi, Anita Pandey
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Publication number: 20100271228Abstract: In one embodiment, a method includes obtaining location information associated with a remote device, and processing the location information. Processing the location information includes determining if the remote device is mobile. The method also includes configuring a filter such that at least one parameter indicates that the remote device is mobile if the remote device is mobile, and configuring the filter such that the at least one parameter indicates that the remote device is approximately stationary if the remote device is not mobile. The filter is applied to the location information to generate a filtered location estimate which is arranged to estimate a location of the remote device.Type: ApplicationFiled: April 27, 2009Publication date: October 28, 2010Applicant: CISCO TECHNOLOGY, INC.Inventors: Matthew Aaron Silverman, Santosh G. Pandey, Brian Donald Hart
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Publication number: 20100238917Abstract: 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: ApplicationFiled: March 17, 2009Publication date: September 23, 2010Inventors: Matthew Aaron SILVERMAN, Paul Jeffrey Stager, Brian Donald Hart
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Publication number: 20090327333Abstract: At a plurality of first devices, wireless transmissions are received at different locations in a region where multiple target devices may be emitting. Identifier data associated with reception of emissions from target devices at multiple first devices is generated. Similar identifier data associated with received emissions at multiple first devices are grouped together into a cluster record that potentially represents the same target device detected by multiple first devices. Data is stored that represents a plurality of cluster records from identifier data associated with received emissions made over time by multiple first devices. The cluster records are analyzed over time to correlate detections of target devices across multiple first devices.Type: ApplicationFiled: June 30, 2008Publication date: December 31, 2009Applicant: CISCO TECHNOLOGY, INC.Inventors: Neil R. Diener, Gary L. Sugar, Brian Donald Hart, Igal Gutkin, David Kloper
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Patent number: 7626969Abstract: In one embodiment, a method includes computing a probability surface corresponding to the location probability of the wireless node within a physical region based on the received signal strength data associated with a wireless node and an RF model of the physical region; computing, based on the probability surface, an aggregate probability (Pin) of the wireless node being inside a perimeter defined with the physical region; computing, based on the probability surface, an aggregate probability (Pout) of the wireless node being outside the perimeter; computing a probability ratio of the aggregate probabilities Pin to Pout; and determining whether the wireless node is inside or outside the perimeter based on a comparison of Pout and Pin.Type: GrantFiled: October 4, 2006Date of Patent: December 1, 2009Assignee: Cisco Technology, Inc.Inventors: Brian Donald Hart, Bretton Lee Douglas
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Patent number: 7616555Abstract: In one embodiment, a method includes receiving received signal strength data, computing an aggregate square error surface based on the received signal strength data, computing a probability surface by applying a probability density function to the aggregate error surface, and computing a mean location of a wireless node.Type: GrantFiled: October 3, 2006Date of Patent: November 10, 2009Assignee: Cisco Technology, Inc.Inventor: Brian Donald Hart
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Publication number: 20090274136Abstract: Methods, apparatuses and systems directed to partitioning access points into two or more network access layers, such as overlay and underlay network access layers. According to one implementation of the present invention, a wireless network management system partitions a set of wireless access points into an overlay network for low-functionality clients and an underlay network for high-functionality clients. As described in further detail below, each of the overlay and underlay networks provides a class of network service, where each class of network service differs relative to at least one attribute (e.g., type of 802.11 access, data rates, High-Density, Quality-of-Service, encryption, compression, etc.). For didactic purposes, the overlay network is also referred to as the overlay network service layer (NSL) and the underlay network is referred to as the underlay NSL.Type: ApplicationFiled: July 13, 2009Publication date: November 5, 2009Applicant: Cisco Technology, Inc.Inventor: Brian Donald Hart
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Publication number: 20090257426Abstract: A device whose location is to be determined (target device) generates a plurality of frames (messages) and time of departure (TOD) timestamp information indicating when the target device transmits the plurality of frames in a sequence or burst. The target device transmits the plurality of frames and the TOD information, wherein the plurality of frames are transmitted such that at least two of the frames are on different radio frequency (RF) channels. Within a sequence or burst (or across multiple sequences or bursts), multiple widely spaced transmissions on the same channel are included to allow for estimation of the crystal frequency offset of the transmitting device. The TOD information included in the transmitted packets allows devices that receive the packets not to change their channels of operation solely for the purpose of receiving packets from the device to be located.Type: ApplicationFiled: July 7, 2008Publication date: October 15, 2009Applicant: CISCO TECHNOLOGY INC.Inventors: Brian Donald Hart, Paul J. Stager, Allan Thomson
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Patent number: 7596461Abstract: A system for measuring air quality in wireless networks. In particular implementations, a method includes computing an interference severity level for a plurality of interference sources detected at an access point; aggregating one or more of the computed interference severity levels relative to the access point; and computing an air quality metric for the access point, wherein the air quality metric based at least in part on an equation: 1—aggregated interference severity level.Type: GrantFiled: July 6, 2007Date of Patent: September 29, 2009Assignee: Cisco Technology, Inc.Inventors: Brian Donald Hart, Christopher Sean Johnson, Igal Gutkin, Sanjeev Hemantkumar Desal
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Publication number: 20090232001Abstract: A congestion control system. In particular implementations, a method includes receiving packets into one or more queues and monitoring the one or more queues for congestion. The method also includes, if a number of packets in the one or more queues exceeds a first threshold, determining a congestion control mode. The method also includes generating a congestion control message indicating the congestion control mode and transmitting the congestion control message to one or more neighboring mesh nodes.Type: ApplicationFiled: March 11, 2008Publication date: September 17, 2009Applicant: Cisco Technology, Inc.Inventors: Xiaohong Gong, Robert B. O'Hara, JR., Brian Donald Hart, Johannes Petrus Kruys
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Publication number: 20090213820Abstract: 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: ApplicationFiled: February 27, 2008Publication date: August 27, 2009Applicant: CISCO TECHNOLOGY INC.Inventor: Brian Donald Hart
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Patent number: 7580399Abstract: Methods, apparatuses and systems directed to partitioning access points into two or more network access layers, such as overlay and underlay network access layers. According to one implementation of the present invention, a wireless network management system partitions a set of wireless access points into an overlay network for low-functionality clients and an underlay network for high-functionality clients. As described in further detail below, each of the overlay and underlay networks provides a class of network service, where each class of network service differs relative to at least one attribute (e.g., type of 802.11 access, data rates, High-Density, Quality-of-Service, encryption, compression, etc.). For didactic purposes, the overlay network is also referred to as the overlay network service layer (NSL) and the underlay network is referred to as the underlay NSL.Type: GrantFiled: September 14, 2005Date of Patent: August 25, 2009Assignee: Cisco Technology, Inc.Inventor: Brian Donald Hart
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Patent number: 7567822Abstract: In a wireless LAN (WLAN), methods, apparatuses and systems directed to facilitating configuration of a wireless network is provided. According to one implementation of the present invention, sensors are used to collect data associated with locations and other properties of access points of the wireless network. The collected data can then be used to assist in automatically configuring one or more aspects of the wireless network. In some implementations, the collected data can be used to dynamically re-configure the wireless network in real time. According to another implementation of the present invention, location computation mechanisms are used to collect data associated with the location of one or more wireless clients, and the data is used to dynamically adjust one or more radio frequency (RF) coverage maps in real time. The revised RF coverage maps can then be used to re-configure one or more operational parameters of the wireless network.Type: GrantFiled: October 11, 2005Date of Patent: July 28, 2009Assignee: Cisco Technology, Inc.Inventors: Brian Donald Hart, Timothy S. Olson, James Amos, David McClead Theobold, Bretton Lee Douglas
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Publication number: 20090067392Abstract: An apparatus configured to acquire received signal strength intensities (RSSIs) for a wireless device from a plurality of access points (APs) located on a plurality floors. The apparatus is configured to determine which floor the wireless device is on by analyzing the RSSIs. In an example embodiment, the RSSIs are adjusted, and the adjusted RSSIs for each floor are summed. The floor with highest sum of adjusted RSSIs is determined to be the floor the wireless device is on. In an example embodiment, the floor that the wireless device is on is determined by calculating the probability that the wireless device is within the cell of each AP on the network, and combining the probabilities for each floor. Known RSSIs between APs can be employed for comparing measured RSSIs with the known RSSIs to determine the probability that the wireless device is within the cell of each AP.Type: ApplicationFiled: September 7, 2007Publication date: March 12, 2009Inventors: Brian Donald Hart, Anto Jacob, Nirmala Nott Venkataramani, Emilio Maldonado