Abstract:
Providing Precision Timing Protocol (PTP) timing and clock synchronization for wireless multimedia devices is disclosed. In one aspect, a primary wireless multimedia device comprising a timing synchronization control system is provided. The timing synchronization control system is configured to apply a PTP Best-Master-Clock (BMC) algorithm logic to select a master clock from among a system clock of the primary wireless multimedia device, one of one or more connected wireless multimedia devices, or one of one or more external nodes. If the timing synchronization control system selects the system clock of the primary wireless multimedia device, a clock signal of the system clock is provided to the connected wireless multimedia devices as the master clock. If the timing synchronization control system selects a connected wireless multimedia device or an external node as the master clock, the timing synchronization control system synchronizes the system clock with the master clock.
Abstract:
Methods and apparatuses of improving quality of positioning are disclosed. According to aspects of the present disclosure, a transition from a short training field to a long training field in one or more communication messages between two wireless stations may be detected. A station may then determine a first arrival correction time based on the transition from the short training field and the long training field. With the first arrival correction time, more accurate timing of communications between the two wireless stations may be determined and used for improving quality of positioning applications.
Abstract:
Systems, apparatus and methods for determining a cyclic shift delay (CSD) mode from a plurality of CSD modes is disclosed. A received OFDM signal is converted to a channel impulse response (CIR) signal in the time domain and/or a channel frequency response (CFR) signal in the frequency domain. Matched filters and a comparator are used to determine a most likely current CSD mode. Alternatively, a classifier is used with a number of inputs including outputs from two or more matched filters and one or more outputs from a feature extractor. The feature extractor extracts features in the time domain from the CIR signal and/or in the frequency domain from the CFR signal useful in distinguishing various CSD modes.
Abstract:
Techniques for passive positioning of a client station are disclosed. In an example a passive positioning scheme may include detecting an incoming message from an access point, determining a Round Trip Time (RTT) value associated with the access point, generating an acknowledgment message, calculating a time of departure for the acknowledgment message based on the RTT value, and sending the acknowledgment message at the time of departure.
Abstract:
Disclosed are methods and systems for synchronizing clocks maintained at different devices in a wireless communication network. A first wireless transceiver device may receive one or more messages from a second wireless transceiver device with parameters indicative of a first clock state. The first wireless transceiver device may then synchronize a second clock state maintained at the first wireless device based, at least in part, on the one or more parameters indicative of the first clock state.
Abstract:
Apparatuses and methods are disclosed that may perform ranging operations between an initiator device and a responder device. The initiator device may request the responder device to perform a ranging operation. The responder device may transmit a first fine timing measurement (FTM) frame to the initiator device, may receive an acknowledgement (ACK) frame from the responder device, and may transmit a second FTM frame to the initiator device. The second FTM frame may include a time value and angle information. The time value may indicate a difference between a time of departure (TOD) of the first FTM frame and a time of arrival (TOA) of the ACK frame. The angle information may indicate a direction of the initiator device relative to the responder device. The initiator device may determine its position, relative to the responder device, based at least in part on the received time value and angle information.
Abstract:
Apparatuses and methods are disclosed that may perform ranging operations between an initiator device and a responder device. The initiator device may request the responder device to perform a ranging operation. The responder device may transmit a first fine timing measurement (FTM) frame to the initiator device, may receive an acknowledgement (ACK) frame from the responder device, and may transmit a second FTM frame to the initiator device. The second FTM frame may include a time value and angle information. The time value may indicate a difference between a time of departure (TOD) of the first FTM frame and a time of arrival (TOA) of the ACK frame. The angle information may indicate a direction of the initiator device relative to the responder device.
Abstract:
Methods and apparatuses are disclosed that may perform simultaneous ranging operations between a requester device and each of a plurality of target devices using OFDMA-based frame exchanges while maintaining a level of accuracy comparable to ranging operations that do not use OFDMA-based frame exchanges. Tone interleaving may be used so that the ranging devices may estimate channel conditions for the full frequency spectrum of the wireless medium. For example, a unique set of two or more non-adjacent groups of OFDM sub-carrier frequencies may be allocated to each of the plurality of target devices for ranging operations.
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:
In a procedure for determining distance (or angle) between a pair of electronic devices wirelessly connected to one another, a current session may be temporarily suspended on request and thereafter the current session may be resumed. Temporary suspension and resumption of the current session may, for example, eliminate starting a new session between the pair of electronic devices and repeating a determination of parameters that were initially agreed upon in the current session. Temporary suspension of a current session may be signaled wirelessly, by one electronic device to the other electronic device, for example, by setting a specific value in a specific field, to signal that the current session is to be paused now, in a frame or message transmitted from the pausing device to the to-be-paused device. The current session may be resumed without repeating determination of the initially-agreed upon parameters, by transmitting a frame to initiate measurement exchange.