Patent application number | Description | Published |
20080225737 | Dynamic Rate Limiting in Wireless Mesh Networks - A dynamic rate limiting mechanism for wireless mesh networks. In particular implementations, a method comprising monitoring one or more clients associated with a wireless mesh network and the respective hop counts of the clients to a root mesh node of the wireless mesh network; determining, responsive ton one or more events, a client data rate for one or more clients of the wireless mesh network based on the number of current clients and the respective hop counts of the current clients; and applying the client data rate to the wireless mesh network. | 09-18-2008 |
20090012738 | Measurement of Air Quality in Wireless Networks - 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. | 01-08-2009 |
20090052382 | Infrastructure-Based Enabling Indication for Dynamic Frequency Selection in Wireless Networks - A wireless access point selection system. In particular implementations, a method includes receiving a notification that identifies a wireless access point that detects radar on an operating channel and identifies the operating channel; updating neighbor lists of one or more neighboring wireless access points to remove the wireless access point from the neighbor list, where the neighbor list comprises neighbor wireless access points, corresponding operating channels, and corresponding enable indications, where each enable indication indicates if a channel availability check is required before performing active scanning; and transmitting the updated neighbor list to the neighboring wireless access points. In one implementation, a system provides a DFS enable indication to wireless clients so they can know whether a channel availability check is required prior to transmitting. | 02-26-2009 |
20090067392 | FLOOR DETERMINATION FOR A WIRELESS DEVICE - 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. | 03-12-2009 |
20090067403 | Selecting Wider Bandwidth Channels in a Wireless Network - 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. | 03-12-2009 |
20090213820 | Appending a Ranging Waveform to a Frame to Maintain Communication Protocol Interoperability - 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. | 08-27-2009 |
20090257426 | INSERTING TIME OF DEPARTURE INFORMATION IN FRAMES TO SUPPORT MULTI-CHANNEL LOCATION TECHNIQUES - 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. | 10-15-2009 |
20090327333 | Correlating Multiple Detections of Wireless Devices Without a Unique Identifier - 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. | 12-31-2009 |
20100238917 | CLOCK SYNCHRONIZATION - 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. | 09-23-2010 |
20100271228 | LOCATION FILTERING BASED ON DEVICE MOBILITY CLASSIFICATION - 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. | 10-28-2010 |
20110026441 | DYNAMICALLY DEDICATED WIRELESS LOCAL AREA NETWORK SERVICE FOR HIGH DEFINITION VIDEO TELECONFERENCING - 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. | 02-03-2011 |
20110110293 | Location tracking using response messages identifying a tracked device in a wireless network - 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. An apparatus for location tracking is also disclosed. | 05-12-2011 |
20120163331 | Selecting Wider Bandwidth Channels in a Wireless Network - 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. | 06-28-2012 |
20120280714 | CLOCK SYNCHRONIZATION - 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. | 11-08-2012 |
20120314583 | COEXISTENCE MECHANISM FOR MULTIPLE CHANNELS - 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. | 12-13-2012 |
20130010731 | DYNAMICALLY DEDICATED WIRELESS LOCAL AREA NETWORK SERVICE FOR HIGH DEFINITION VIDEO TELECONFERENCING - 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. | 01-10-2013 |
20130100952 | PROVIDING MULTICAST TRANSMISSIONS WITH PARTIAL STATE BLOCK ACKNOWLEDGMENTS AND RETRIES - 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. | 04-25-2013 |
20130177110 | Mid-Packet Clear Channel Assessment - 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. | 07-11-2013 |
20130279349 | GENERATING ACCURATE DYNAMIC HEAT MAPS - 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. | 10-24-2013 |
20130287131 | Two Stage Precoding for Multi-User MIMO Systems - 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. The principal component-like single-client channel matrices are combined to form a principal component-like multi-user channel matrix, from which the precoding matrix is computed. | 10-31-2013 |
20140052508 | ROGUE SERVICE ADVERTISEMENT DETECTION - 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. | 02-20-2014 |
20140062789 | LOCATION ESTIMATION FOR WIRELESS DEVICES - 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. | 03-06-2014 |
20140105395 | LOCATION SERVICES FOR A WIRELESS DEVICE - 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. | 04-17-2014 |
20140327579 | ANGLE OF ARRIVAL LOCATION SENSING WITH ANTENNA ARRAY - 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. | 11-06-2014 |