Hewlett Packard Enterprise Development LP

Hewlett-packard Development Company, L.p.

University of California

Duke University

Souvik Sen

Jung Gun Lee

Dongho Kim

Jeongkeun Lee

Kyu-Han Kim

Kyu Han Kim

Anil Gupta

Manfred R Arndt

Li Sun

David D Lee

Stephane Laroche

Martin Robert Fink

Alexander Timothy Mariakakis

Jean Tourrilhes

Ioannis Pefkianakis

Romit Roy Choudhury

Bowon Lee

Raul Herman Etkin

Prasant Mohapatra

Sanjib Sur

Nirupam Roy

He Wang

Jeremy Gummeson

Jindan Zhu

Eduardo Alberto Cuervo Laffaye

Benjamin E Andow

Mili Hoxha

Mostafa Abdulla Zahid Uddin

Haiqing Jiang

Tom Hogan

Moustafa Youssef

Ahmed Elgohary

Moustafa Farid

David Lee

Martin R Fink

An example system includes a transceiver. The transceiver communicates multicast frames to a plurality of client devices in a multicast group. The system further includes a controller. The controller determines that a predetermined time has passed since the transceiver most recently sent a unicast transmission to one of the plurality of client devices. The controller instructs the transceiver to transmit a unicast frame to the one of the plurality of client devices. The controller computes a data rate for the one of the plurality of client devices based on the transmission of the unicast frame to the one of the plurality of client devices.

Transmissions of unicast frames to client devices

Described herein are techniques for performing a channel scan based on a mobility state of a device. The mobility state of a device relative to an access point may be determined using time-of-flight information. A channel scan may be performed based on the mobility state determination.

Channel scan based on mobility state

A method of determining the location of a mobile computing device includes measuring a first time of flight (ToF) value and a first value of received energy of direct path (EDP) (P) of a number of acknowledgement (ACK) packets received in response to a number of first probe packets sent to a first mobile device. The method calculates a preliminary distance value (d) using a ToF-based distance equation, selects an ACK packet with a distance closest to dfrom the number of ACK packets, calculates an initial path loss exponent (&#x3b3;) of the selected ACK packet sample using dand P. With the access point, the method also includes measuring a second Pfor a second number of ACK packets received in response to a number of second probe packets sent to the first mobile device, calculates a supplemental distance value using an EDP-based distance equation and the &#x3b3;, and determines the location of the mobile device using multilateration and the supplemental distance value.

Determining the location of a mobile computing device

Described herein are techniques for beamforming a wireless signal to a harvesting device. In an example, a method to increase available energy to a harvesting device is performed by a WiFi transmitting device. The WiFi transmitting device determines a preferred wireless path to the harvesting device using input from a proxy device. The WiFi transmitting device then beamforms a WiFi signal to the harvesting device along the preferred wireless path.

Beamforming to a harvesting device

In an example, a method for correcting time-of-flight measurements includes receiving a plurality of time-of-flight measurements and determining whether the time-of-flight measurements relate to a strong signal client, a weak signal client, or a preferred signal client. If the time-of-flight measurements relate to a strong signal client or a weak signal client, the method determines whether the time-of-flight measurements constitute two distinct distributions. If the time-of-flight measurements constitute two distinct distributions, a mean value for each distribution is determined. If the mean values differ by a predetermined time delay attributable to automatic gain control processing, the time-of-flight measurements corresponding to the distribution having the lower mean value are used. If the mean values differ by less than the predetermined time delay attributable to automatic gain control processing, the time-of-flight measurements corresponding to both distributions are used.

Correcting time-of-flight measurements

Example implementations relate to determining a location using time difference of arrival (TDOA). For example, a computing device may include a first sensor to receive a signal at a first time, where the signal is generated by a user contact at a particular location on a keyboard associated with the computing device. The computing device also includes a second sensor to receive the signal at a second time and a third sensor to receive the signal at a third time. The computing device may also include a processor. The processor may calculate a set of TDOAs associated with the first time, the second time, and the third time. The processor may determine the particular location of the user contact using a triangulation based on the set of TDOAs and may identify a character on the keyboard, where the character is associated with the particular location.

Determining location using time difference of arrival

An example communications device includes communications circuitry and control circuitry. The communications circuitry may wirelessly communicate with client devices. The control circuitry may determine signal-to-interference-plus-noise ratios (SINRs) for the client devices based on compressed client-side channel state information received from the client devices. The control circuitry may assign the client devices to multi-user-multiple-input-multiple-output (MU-MIMO) groups based on the SINRs.

MU-MIMO group assignment

Examples herein disclose capturing a wifi signal from a computing device corresponding to a computing accessory and harvesting energy from the captured wifi signal. The examples power the computing accessory based on the harvested energy.

Supplying power to a computer accessory from a captured wifi signal

Described herein are techniques for selecting a subset of access points. In an example, a wireless access point stores a plurality of unique keys, each unique key being associated with a respective device. The access point advertises a first service set identifier, the first service set identifier requiring authentication of a device requesting connection at a remotely located authentication server. The access point monitors a connection to the remotely located authentication server, and, in response to the connection going down, advertising a second service set identifier, the second service set identifier requiring authentication of a device requesting connection using the unique key associated with the device requesting connection.

Advertising multiple service set identifiers

The present disclosure is generally related to a method for wireless software-defined networking. The method includes establishing a wireless link between an access point of a network and a plurality of client devices. The method includes generating a time schedule. The time schedule allocates a time window to each of the plurality of client devices. Each time window defines when a plurality of client devices is allowed to communicate within the network via the access point.

Wireless software-defined networking

According to an example, mobility-aware frame aggregation may include using mobility information related to a transmitter and/or a receiver associated with transmission of data over a wireless channel to determine an aggregation size for frame aggregation of the data to be transmitted over the wireless channel. The mobility information may be based on subcarriers and antennas related to the wireless channel.

Mobility-aware frame aggregation

Described herein are techniques for determining a location of a disconnected device. In an example, a method includes instructing a first access point to sniff a wireless channel for probe request packets from disconnected devices, and instructing the first access point to send a distance-probing packet to a disconnected device after receiving a probe request packet from the disconnected device. The method further includes receiving, from the first access point, a MAC address of the disconnected device determined from the received probe request packet. After receiving the MAC address from the first access point, a group of access points is instructed to send distance-probing packets to the disconnected device. The method further includes receiving, from the first access point and the group of access points, time-of-flight measurements associated with the disconnected device. A location of the disconnected device can be determined using the time-of-flight measurements.

Determining a location of a disconnected device

A technique includes determining a consumption time for content received in a mobile device from a cellular network, where the consumption time represents a time at which the content is received in the mobile device to a time at which content associated with the received content is consumed at an output sink of the mobile device. The technique includes regulating a power consumption state of a cellular radio of the mobile device based at least in part on the consumption time.

Regulating a power consumption state of a cellular radio

Localizing a location of a mobile device may be performed by obtaining times of flights between the mobile device and an access point at a first and second location. A heading of the mobile device and a distance between the first and second location may be further obtained. The times of flight, heading, and distance may be used to localize the second location.

Growing community of inventors

Mountain View, CA, United States of America

Souvik Sen