Abstract: Techniques for estimating a position of an observing station are disclosed based on capturing, at the observing station, a first and a second FTM message exchanged between a first messaging station and a second messaging station. At the observing station, a first time of arrival of the first FTM message and a second time of arrival of the second FTM message may be determined. Based on contents of one or more FTM messages, a first transmission-related time associated with the first FTM message and a second transmission-related time associated with the second FTM message may be obtained. The position of the observing station may be estimated based on (1) a position of the first messaging station, (2) a position of the second messaging station, (3) the first time of arrival, (4) the second time of arrival, (5) the first transmission-related time, and (6) the second transmission-related time.

Abstract: Techniques for estimating a position of an observing station are disclosed based on capturing, at the observing station, a first and a second FTM message exchanged between a first messaging station and a second messaging station. At the observing station, a first time of arrival of the first FTM message and a second time of arrival of the second FTM message may be determined. Based on contents of one or more FTM messages, a first transmission-related time associated with the first FTM message and a second transmission-related time associated with the second FTM message may be obtained. The position of the observing station may be estimated based on (1) a position of the first messaging station, (2) a position of the second messaging station, (3) the first time of arrival, (4) the second time of arrival, (5) the first transmission-related time, and (6) the second transmission-related time.

Abstract: A ranging operation between a first wireless device and a second wireless may be performed by: sending, to the second wireless device, a data frame including a request for the second wireless device to report its actual SIFS duration to the first wireless device; determining a time of departure (TOD) of the data frame; receiving, from the second wireless device, a response frame including SIFS information indicative of the actual SIFS duration of the second wireless device; determining a time of arrival (TOA) of the response frame; and determining a round trip time (RTT) of the data frame and the response frame using the TOD of the data frame, the TOA of the response frame, and the actual SIFS duration of the second wireless device.

Abstract: This disclosure provides systems, methods and apparatuses for detecting a presence of long training fields (LTFs) in packet extensions of high-efficiency (HE) packets. An apparatus requests a length of packet extensions to be used for a ranging operation. The apparatus receives an HE packet including a packet extension containing a selected number of LTFs based at least in part on the requested packet extension length. The apparatus performs the ranging operation based on a determination that the packet extension contains LTFs. In some aspects, the apparatus detects a presence of LTFs in the packet extension based on a bit provided in the HE packet. In some other aspects, the apparatus detects a presence of LTFs in the packet extension by extracting sequences from the packet extension.

Abstract: Disclosed herein are techniques for range measurement between one or more wireless stations (STAs) and a first access point (AP). In various embodiments, the first AP may synchronize a clock of the first AP with clocks of one or more synchronized APs. The first AP may perform a synchronization session with the one or more STAs. The first AP may also transmit one or more Broadcast time-of-departure (TOD) frames to the one or more STAs. Each of the one or more Broadcast TOD frames may include a time of departure of a Broadcast TOD frame from the first AP. A second AP and a third AP of the one or more synchronized APs may also transmit one or more Broadcast TOD frames to the one or more STAs for range and/or position determination.

Abstract: Disclosed are systems, methods and devices for obtaining round trip time measurements for use in location based services. In particular implementations, a fine timing measurement request message wirelessly transmitted by a first transceiver device to a second transceiver device may permit additional processing features in computing or applying a signal round trip time measurement. Such a signal round trip time measurement may be used in positioning operations.

Abstract: Methods, systems, and devices are described for wireless communication. An example method includes receiving, by a first wireless communication device having a plurality of antennas disposed at a localized position, a plurality of fine timing management (FTM) messages from a second wireless communication device. The example method includes transmitting, by the first wireless communication device, a plurality of FTM responses to the second wireless communication device. Each of the plurality of FTM responses may be transmitted using a different antenna of the first wireless communication device. The example method also includes estimating a range between the first wireless communication device and the second wireless communication device based at least in part on the plurality of FTM messages.

Abstract: Methods, systems, and devices for wireless communication are described. An access point (AP) may switch antenna array configurations during reception of a packet to determine channel characteristic information for the antenna array configurations. The AP may use the channel characteristic information to select an antenna array configuration for use, and to determine a beamforming steering matrix for the selected antenna array configuration. In some cases, the AP may use multiple antenna array configurations to transmit training fields in the preamble of a packet. The AP may receive channel characteristic information for each of the antenna array configurations. The AP may use the channel characteristic information to select an antenna array configuration for use, and to determine a beamforming steering matrix for the selected antenna array configuration.

Abstract: This disclosure provides systems, methods and apparatuses for selecting a guard interval for transmission of orthogonal frequency-division multiplexing (OFDM) symbols on an uplink (UL) channel and on a downlink (DL) channel. In some implementations, a transmitting device and a receiving device can estimate channel delay spread (CDS) information for each other's transmit channels, exchange the estimated CDS information with each other, and select a guard interval based on the estimated CDS information exchanged with each other. The transmitting device can transmit a number of OFDM symbols separated by the selected guard interval to the receiving device on the UL channel, and the receiving device can transmit a number of OFDM symbols separated by the selected guard interval to the transmitting device on the DL channel.

Abstract: Embodiments of the present disclosure relate to the field of display technologies, and disclose a method and device for adjusting screen luminance, and a display device that includes the device for adjusting screen luminance. According to the present disclosure, screen luminance may be adjusted directly according to the eye comfort degree so as to achieve the objective of protecting eyes. The method for adjusting screen luminance includes: detecting a pupil size of a user; and adjusting the screen luminance according to the pupil size, such that the adjusted luminance is in a range within which human eyes are comfortable.

Abstract: This disclosure provides systems, methods and apparatuses for performing ranging operations between wireless devices. In some implementations, wireless devices can exchange ranging packets that include packet extensions containing a plurality of long training fields (LTFs). The wireless devices can use the LTFs in the ranging packets to obtain a plurality of round-trip time (RTT) values based on a single exchange of ranging packets. The wireless devices also can use the LTFs to estimate angle of arrival (AoA) and angle of departure (AoD) information of the exchanged ranging packets.

Abstract: This disclosure provides systems, methods and apparatuses for performing ranging operations between a transmitting device and one or more receiving devices using one or more wireless channels. In some implementations, a transmitting device may substantially concurrently exchange, on each of a plurality of wireless channels, a corresponding set of FTM frames and acknowledgement (ACK) frames with a receiving device, and then determine a distance to the receiving device based on the plurality of exchanged sets of FTM and ACK frames. In some other implementations, the transmitting device may substantially concurrently exchange, with each of a plurality of receiving devices, a corresponding set of FTM frames and ACK frames on a corresponding one of a plurality of wireless channels, and then determine a distance to each of the plurality of receiving devices based on the corresponding sets of exchanged FTM and ACK frames.

Abstract: Disclosed embodiments facilitate wireless channel calibration, ranging, and direction finding, between networked devices. A method on a first station (STA) may comprise: broadcasting, at a first time, a first NDPA frame to a plurality of second STAs. The first NDPA frame may include a first bit indicating that one or more subsequent frames comprise ranging or angular information. After a Short Interval Frame Space (SIFS) time interval from the first time, a second frame may be broadcast. The second frame may be a Null Data Packet (NDP) frame. In response, a plurality of Compressed Beamforming (CBF) frames may be received at the first STA where each CBF frame may be received from a distinct corresponding second STA, and may include Channel Feedback Information field with information pertaining to communication channel between the first STA and the corresponding second STA. The communications may be encoded using Orthogonal Frequency Division Multiple Access.

Abstract: Disclosed embodiments facilitate wireless channel calibration, including ranging and direction finding, between wirelessly networked devices. In some embodiments. a method on a first station (STA) may comprise: transmitting a first NDPA frame to one or more second stations (STAs), the first NDPA frame comprising a first bit indicating that one or more subsequent frames comprise ranging or angular information; and transmitting, after a Short Interval Frame Space (SIFS) time interval, a second frame. The second frame may be one of: a Null Data Packet az (NDP_az) frame with information about a time of transmission of the NDP_az frame, or a Null Data Packet (NDP) frame, or a Beam Refinement Protocol (BRP) frame. The first NDPA frame may be unicast, multicast, or broadcast.

Abstract: Apparatuses and methods are disclosed that may perform ranging operations between a first device and a second device. The second device transmits an FTM request frame indicating a number of supported non-legacy ACK frame formats, and receives a first FTM frame indicating capabilities of the first device to receive each of the non-legacy ACK frame formats supported by the second device. The second device selects one of the non-legacy ACK frame formats or a legacy ACK frame format based, at least in part, on the indicated capabilities of the first device, and then transmits ACK frames using the selected frame format during the ranging operation.

Abstract: Apparatuses and methods for performing multi-channel passive ranging operations are disclosed. In one example, a passive listening device may receive, on a first wireless channel, a first exchange of signals between a first wireless device and a second wireless device, and then receive on a second wireless channel, a second exchange of signals between the first wireless device and the second wireless device, the first wireless channel different than the second wireless channel. The passive listening device may determine a differential distance between the passive listening device and the first and second wireless devices based, at least in part, on the first and second exchanges of signals on the first and second wireless channels, respectively.

Abstract: Disclosed are methods, systems and devices for obtaining a range between devices based, at least in part, on an exchange of wireless messages. For example, wireless devices may obtain measurements of range based, at least in part, on an exchange fine timing measurement (FTM) messages. In one implementation, an initial FTM request message may be transmitted from a first wireless transceiver device to a second wireless transceiver device comprising one or more parameters indicative of a request for transmission of FTM messages in a particular format.

Abstract: Disclosed are systems, methods and devices for obtaining round trip time measurements for use in location based services. In particular implementations, a fine timing measurement request message wirelessly transmitted by a first transceiver device to a second transceiver device may permit additional processing features in computing or applying a signal round trip time measurement. Such a signal round trip time measurement may be used in positioning operations.

Abstract: Disclosed herein are techniques for range measurement between one or more wireless stations (STAs) and a first access point (AP). In various embodiments, the first AP may synchronize a clock of the first AP with clocks of one or more synchronized APs. The first AP may perform a synchronization session with the one or more STAs. The first AP may also transmit one or more Broadcast time-of-departure (TOD) frames to the one or more STAs. Each of the one or more Broadcast TOD frames may include a time of departure of a Broadcast TOD frame from the first AP. A second AP and a third AP of the one or more synchronized APs may also transmit one or more Broadcast TOD frames to the one or more STAs for range and/or position determination.

Abstract: Techniques for determining a device location based on measurements from multiple RATs are described. In an aspect, the methods and apparatus include determining, at a first device, one or more round trip time (RTT) measurements based on one or more signals communicated with a second device over a first Radio Access Technology (RAT). Further, in an aspect, the methods and apparatus include determining, at the first device, one or more angle measurements based on one or more signals communicated with the second device over a second RAT. Additionally, the methods and apparatus include determining a location of the first device in relation to the second device based on the one or more RTT measurements and the one or more angle measurements. The one or more angle measurements may include one or more angle of departure (AoD) measurements, one or more angle of arrival (AoA) measurements, or both.