Abstract: Methods, devices, and apparatuses are described for wireless communications using a multidimensional algorithm for roaming. In one aspect, an initial set of candidate access points (APs) is produced by a station using a roaming scan. The initial set may be identified based at least in part on an initial metric (e.g., beacon signal strength). A probe signal may be transmitted by the station to at least one of the candidate APs in the initial set and information may be received in response to the probe signals. The station may then identify a reduced set from the initial set based at least in part on the received information, where the reduced set is used to select a target AP. At least one additional metric may be identified and the probe signal may be configured to obtain information corresponding to the additional metrics. This information may be used by the station to select the candidate APs in the reduced set.

Abstract: Power saving for wireless communication devices by adjusting the amount of time, after a last transmission/reception of data, that the device remains in an awake mode listening for more data before the device enters a sleep mode. This time period may be referred to as inactivity time interval or inactivity timeout (ITO). The described features may be employed to improve power savings by taking metrics of channel congestion into account for determining the ITO. The appropriate ITO may be determined to be commensurate with ongoing transmission and/or reception activity. Because error may occur in estimating channel congestion and/or transmission/reception activity, latency bounds based on estimation errors may be managed by classifying the operational mode into multiple regions and employing techniques for mitigating error in congestion estimation based at least in part on the operational mode.

Abstract: This disclosure describes techniques for operating a client device to communicate with a wireless access point to validate data within a frame by comparing channel quality metrics and duration metrics to thresholds. Information received within a validity window may be treated as correctly received even if the frame fails a subsequent verification process or if reception of the frame is terminated prior to the end of the frame.

Abstract: Methods and apparatuses are described for wireless communications coexistence. In one aspect, a first device may detect an interference produced by a second device co-located with the first device. The first device may communicate with an access point (AP) using a free or open band and the second device may communicate with a cellular network (e.g., LTE network). In response to the detected interference, a message may be transmitted to the AP from the first device with information for the AP to determine whether to switch to a different channel in the open band to communicate with the first device. The AP may receive such a message from each terminal in at least a subset of associated terminals. The AP may determine, from the messages received, to switch to the different channel in the open band and may transmit a message to the associated terminals indicating the switch.

Abstract: A system and method are disclosed for performing ranging operations between two wireless devices without employing cyclic shift diversity (CSD) compensation techniques. For some embodiments, a first wireless device sends a negotiation request frame requesting the second wireless device to respond to subsequently received frames of a specified type using a selected one of the transmit chains in the second wireless device. Thereafter, the first wireless device sends a data frame to the second wireless device to initiate a ranging operation. The second wireless device sends a response frame of the specified type to the first wireless device using the selected one of the transmit chains.

Abstract: A method and apparatus are disclosed for increasing the speed with which a number of stations associated with an IBSS network may be synchronized and/or for reducing the number of beacon frame collisions in the IBSS network. For at least some embodiments, the synchronization speed may be increased by allowing STAs having faster clock speeds to broadcast beacon frames more frequently than STAs having slower clock speeds.

Abstract: This disclosure describes techniques for operating a client device to communicate with a wireless access point to validate data within a frame by comparing channel quality metrics and duration metrics to thresholds. Information received within a validity window may be treated as correctly received even if the frame fails a subsequent verification process or if reception of the frame is terminated prior to the end of the frame.

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 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 power conservation in a wireless communications system through efficient transmissions and acknowledgements of information between an AP and a station. The time between a determination by a station to enter a power saving mode and entering network sleep mode by the station may be reduced through a transmission, by an AP, of an MPDU to the station successive to an SIFS after transmission of an acknowledgement to the station of a PS-Poll frame from the station. The time to enter a power saving mode by a station may also be reduced through transmission of A-MPDUs in which a last MPDU of the A-MPDU has an indicator bit cleared to indicate no additional data is to be transmitted. An AP may prevent a retransmission of an MPDU to the station in the absence of an acknowledgement from the station, to further enhance efficiency.

Abstract: Methods, systems, and devices are described for power conservation in a wireless communications system through efficient transmissions and acknowledgements of information between an AP and a station. The time between a determination by a station to enter a power saving mode and entering network sleep mode by the station may be reduced through a transmission, by an AP, of an MPDU to the station successive to an SIFS after transmission of an acknowledgement to the station of a PS-Poll frame from the station. The time to enter a power saving mode by a station may also be reduced through transmission of A-MPDUs in which a last MPDU of the A-MPDU has an indicator bit cleared to indicate no additional data is to be transmitted. An AP may prevent a retransmission of an MPDU to the station in the absence of an acknowledgement from the station, to further enhance efficiency.

Abstract: A wireless device that operates in accordance with the IEEE 802.11 standard receives the preamble of a packet with the highest number of receive chains enabled, thereby obtaining the highest gain, detection sensitivity and range. The wireless device determines a signal-to-noise ratio (SNR) in response to two different short training fields (STFs) in the preamble. The wireless device also determines a modulation and coding scheme (MCS) and a number of spatial streams (Nss) used to transmit the received packet in response to a signal field of the preamble. The wireless device uses these determined parameters to identify a minimum number of the receive chains required to reliably receive the packet. The wireless device uses only the identified minimum number of receive chains to perform channel estimation and receive the data portion of the packet.

Abstract: This disclosure includes systems and methods for determining the location of each of a plurality of STAs of a WLAN where an AP measures the round-trip time (RTT) and the angle of arrival (AOA) to each STA from implicit packet exchange, such as data frame and ACK frame. The AP may then report the RTT and AOA measurements to each STA using a dedicated beacon information element (IE) which multicasts RTT and AOA measurements to the STAs. By employing an additional parameter, namely, angle of arrival AOA, a single AP may compute the two-dimensional location of each associated STA. Further, another beacon IE may multicast mapping of the AIDs to MAC addresses so that the associated STAs can understand such mapping for STAs in a network so that one STA may know the location of other STAs. Encryption may be employed to achieve privacy.

Abstract: Methods, systems, and devices are described for a wireless positioning framework in which an access point (AP) broadcasts a message within a beacon interval that identifies a transmission schedule for a set of stations. The message may include an information element identifying the stations in the set. The set may be determined based on station clock drifts and/or a ranging accuracy sought by the AP. The AP may also provide a station identifier, and frame spacing and delay parameters, which may be used to determine a distinct backoff for each station. Using distinct backoffs allow the stations to avoid collisions when sending the transmissions. The AP may receive the transmissions according to the identified schedule and may determine a range (e.g., round-trip time) for each station in the set based at least on a time at which the respective transmission is received.

Abstract: Methods and apparatuses are described in which dynamic voltage and frequency scaling may be used to save power when processing packets in a wireless communications device. In some cases, inframe detection may allow the device to determine whether to transition from a first (e.g., lower) voltage level to a second (e.g., higher) voltage level to process one or more packets of a received frame. For some packet types the first voltage level may be maintained. In other cases, the device may determine a bandwidth to use from among multiple bandwidths supported by the device. The bandwidth may be determined based on channel conditions. A voltage level may be identified that corresponds to the determined bandwidth and a processing voltage may be scaled to the identified voltage level. The device may be configured to operate in wireless local area network (WLAN) and/or in a cellular network (e.g., LTE).

Abstract: Methods, apparatuses, systems, and devices are described for wireless communication. In one configuration, an allocation of physical resources to be utilized by a wireless communication device during one or more portions of a subframe may be received at the wireless communication device. There may then be determined, based on the received allocation of physical resources, one or more bandwidths to be utilized at the wireless communication device during the one or more portions of the subframe. At least one of a voltage level or a clock frequency of the wireless communication device may be adjusted to process the one or more portions of the subframe. The at least one of the voltage level or the clock frequency may be adjusted based on the determined one or more bandwidths.

Abstract: A method and apparatus for broadcasting short interframe space information to aid in determining a round trip time are provided. The round trip time is used as an aid in locating nodes within a WiFi or WLAN network. The method begins with capturing a time of transmission of a frame by a transmitting station. The receiving station then captures the time of arrival of the frame just sent by the transmitting station. The receiving station replies with a received frame message and the time of departure is captured. The transmitting station then captures the time of arrival of the received frame message. The captured arrival and departure times of the frame and the received frame message allow the round trip time to be computed. The RTT may then be included as part of a network message.

Abstract: In one embodiment, a wireless access point (AP) receives messages from a wireless wide area network (WWAN) device, wherein these messages identify parameters of future WWAN frames. Each message identifies a starting time, an operating band, an upload/download sub-frame configuration, and a special sub-frame pattern of a WWAN frame. The AP uses the parameters defined by each received message to determine whether to transmit a beacon frame at a scheduled target beacon transmission time (TBTT), or delay the transmission of the beacon frame to a delayed TBTT. The AP will not delay the scheduled TBTT if the parameters defined by the received message indicate there are no co-existence problems. However, the AP will delay a transmission from the scheduled TBTT if this scheduled TBTT coincides with a downlink sub-frame of the WWAN frame, and the WWAN frame has an operating band subject to interference from the intended transmission.

Abstract: Systems and methods are disclosed for coordinating operation on multiple frequency bands between two or more multiple concurrent band (MCB) devices. The band switch protocols may include sending information on a second band after a communications link has been established on a first band. The receiving device may treat the transmission of the frame on the new band as a message to switch bands, such that the transmitting and receiving devices may conduct subsequent communications on the new band. Further, the band switch protocols allow for seamless operation over the band switch event. As a result, a frequency band having desired performance characteristics may be selected dynamically.

Abstract: A wireless device that operates in accordance with the IEEE 802.11 standard receives the preamble of a packet with the highest number of receive chains enabled, thereby obtaining the highest gain, detection sensitivity and range. The wireless device determines a signal-to-noise ratio (SNR) in response to two different short training fields (STFs) in the preamble. The wireless device also determines a modulation and coding scheme (MCS) and a number of spatial streams (Nss) used to transmit the received packet in response to a signal field of the preamble. The wireless device uses these determined parameters to identify a minimum number of the receive chains required to reliably receive the packet. The wireless device uses only the identified minimum number of receive chains to perform channel estimation and receive the data portion of the packet.