Abstract: The present disclosure discloses a distributed system. The distributed system includes a plurality of radio heads and a plurality of controllers disposed in one or more chassis external to the plurality of radio heads. Each of the plurality of controllers includes a baseband unit (BBU), an uplink time-division multiplexing (TDM) switch and a downlink TDM switch. The uplink TDM switch and the downlink TDM switch forward data bits between a radio head and a BBU by using TDM cells which may reduce latency relative to using Ethernet frames.

Abstract: The present disclosure discloses a distributed system. The distributed system includes a plurality of radio heads and a plurality of controllers disposed in one or more chassis external to the plurality of radio heads. Each of the plurality of controllers includes a baseband unit (BBU), an uplink time-division multiplexing (TDM) switch and a downlink TDM switch. The uplink TDM switch and the downlink TDM switch forward data bits between a radio head and a BBU by using TDM cells which may reduce latency relative to using Ethernet frames.

Abstract: A third device stores a receive signal strength of a received response data unit transmitted by a second device after receiving a first data unit transmitted by a first device. The third device obtains a clear channel access parameter included in a header of a second data unit transmitted by the first device to the second device and detects transmission exchanges in each of a plurality of service sets to use as samples of overlapping service set activity. The third device determines a minimum transmit power to be used by the third device to send a transmission to the fourth device based on transmission exchanges between devices in a particular service set. The third device determines whether to send a transmission to the fourth device based on the clear channel access parameter and minimum transmit power.

Abstract: A central processor subsystem controls multiple transceivers. Each transceiver transmits protocol data units from antennas of that transceiver and produces receive waveforms from wirelessly received signals at the one or more antennas. A transmit waveform, including a frame addressed to one or more wireless client devices, is sent through a first transceiver to be transmitted wirelessly by the first transceiver on a frequency channel. A receive waveform, representative of the transmission by the first transceiver and wirelessly received at a second transceiver, is received from the second transceiver. While the transmit waveform is being sent to the first transceiver: a level of collision between the receive waveform and another transmission on the frequency channel is detected; and if the level of collision exceeds a threshold prior to an end of the receive waveform, the transmit waveform being sent to the first transceiver is modified to reduce the collision.

Abstract: Techniques are disclosed to synchronize wireless signal transmission by endpoints controlled by a central controller. For example, an example method of wireless communication includes receiving, at a first device, over a wired medium between the first device and a second device, a plurality of packets from the second device. Each of the plurality of packets comprises data representative of a portion of a signal corresponding to a wireless medium. The method further includes receiving, at the first device, from the second device over the wired medium a synchronization signal based on a common master clock at the second device. The method further includes synchronizing, at the first device, a local clock of the first device to the common master clock based on the synchronization signal. The method further includes reconstructing the signal corresponding to the wireless medium based on the plurality of packets and the synchronized local clock.

Abstract: A pair of Clear Channel Assessment (CCA) rules are presented that protect an initiator's transmission at the responder, and the responder's transmission at the initiator, using additional fields transmitted in a preamble (header) of a Physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU) or in a Media Access Control (MAC) header, if unencrypted and robustly modulated. These techniques enable more parallel/simultaneous transmissions between devices that might otherwise interfere with each other, subject to ensuring an adequate Signal-to-Interface and-Noise Ratio (SINR) for the initiator's transmission at the responder and ensuring an adequate SINR for the responder's transmission at the initiator.

Abstract: Embodiments herein describe calibrating a plurality of radio heads having a plurality of wireless antennas. In one embodiment, the plurality of radio heads communicate a calibration signal in a round robin fashion such that each of the radio heads communicates a respective calibration signal to the remaining radio heads. The received calibration signals are then used to calibrate the radio heads. In one embodiment, a controller coupled with the plurality of radio heads calibrates the radio heads. The calibrated radio heads then communicate to one or more client devices.

Abstract: The present disclosure discloses that a device uses precoding to transmit independent data streams to existing users and additional independent data streams to one or more new users simultaneously. During a first transmission of a first one or more data streams that are precoded using a first precoding matrix, the device determines to transmit a second one or more data streams in a second transmission. Before the first transmission is complete, the device calculates a combined precoding matrix for precoding the first one or more data streams and the second one or more data streams. The device transmits the first one or more data streams in the first transmission and the second one or more data streams in the second transmission simultaneously using the combined precoding matrix.

Abstract: Embodiments herein describe using an intermediate distribution frame (IDF) which is connected between a central controller and a plurality radio heads which each include at least one antenna for wireless communication with a user device. Instead of running separate cables to each of the radio heads, a single cable can be used to connect the IDF to the central controller and then separate cables can be used to connect the IDF to the radio heads. If the IDF is disposed near the radio heads, the amount of cables can be reduced. Moreover, the IDF may recover a clock signal used by the central controller and forward that clock to the plurality of radio head in order to synchronize the radio heads to the central controller.

Abstract: A third device stores a receive signal strength of a received response data unit transmitted by a second device in response to reception by the second device of a first data unit transmitted by a first device, obtains a clear channel access parameter included in a header of a second data unit transmitted by the first device to the second device. The clear channel access parameter is based on a sum of a transmit power used by the first device to transmit the second data unit to the second device and a receive signal strength of the response data unit at the first device. The third device determines a transmit power to be used by the third device to send a transmission to the fourth device based on transmission exchanges between devices in a particular service set.

Abstract: Techniques are disclosed to reduce latency of processing for access points using a central controller. For example, an example method of wireless communication includes receiving, at an access point, a signal wirelessly. The method further includes filtering the signal using a first passband filter having a first bandwidth to generate a first filtered signal. The method further includes filtering the signal using a second passband filter having a second bandwidth to generate a second filtered signal, wherein the first bandwidth is less than the second bandwidth. The method further includes determining whether the signal includes a packet based on the first filtered signal and generating a control signal indicative of the determination. The method further includes transmitting the control signal and the second filtered signal to a central controller.

Abstract: Embodiments herein describe a network device (e.g., an access point) that dynamically arranges multi-user (MU) multiple input multiple output (MIMO) compatible client devices into MU-MIMO groups. That is, the network device uses network metrics and historical data to change the assignment of client devices in the MU-MIMO groups which may improve MU-MIMO efficiency by reducing the amount of power that leaks between the clients devices in the group. In one embodiment, the AP identifies a MU-MIMO group based on a performance evaluation such as evaluating network metric or determining if the group is underutilized. The AP can replace the identified MU-MIMO group with a substitute MU-MIMO group where the substitute MU-MIMO group is selected based on historical data corresponding to the client devices assigned to the substitute MU-MIMO group.

Abstract: The embodiments herein use a factorization based technique for determining filter coefficients for a subset of the subcarriers in a wireless frequency band. Once the filter coefficients for the subset of the subcarriers are calculated, the network device uses these filter coefficients to identify the filter coefficients in a neighboring subcarrier. To do so, the network device uses pseudo-inverse iteration to convert the already calculated filter coefficients into filter coefficients for a neighboring subcarrier. The network device can repeat this process for the next set of neighboring subcarriers until all the filter coefficients have been calculated.

Abstract: A method is provided in which a first wireless access point selects two or more of a plurality of client devices based on similarity of receive signal strength and carrier frequency offset with respect to the first wireless access point, and sends a downlink multi-user multiple-input multiple-output (MIMO) transmission to the two or more client devices. The downlink multi-user MIMO transmission is configured to solicit acknowledgments from the two or more client devices. The acknowledgments are received at a plurality of antennas of the first wireless access point from the two or more client devices. Uplink multi-user MIMO processing of the acknowledgments is performed from the two or more of the plurality of client devices to recover the acknowledgments respectively from each of the two or more client devices.

Abstract: Embodiments herein describe calibrating a plurality of radio heads having a plurality of wireless antennas. In one embodiment, the plurality of radio heads communicate a calibration signal in a round robin fashion such that each of the radio heads communicates a respective calibration signal to the remaining radio heads. In one embodiment, at least one of the radio heads is isolated from the remaining radio heads. The received calibration signals are then used to calibrate the radio heads. In one embodiment, a controller coupled with the plurality of radio heads calibrates the radio heads. The calibrated radio heads then communicate to one or more client devices.

Abstract: Embodiments herein describe recovering data packets received by a plurality of wireless antennas of a radio head. In one embodiment, the signals received by the radio head are filtered using a single filter to recover at least one data packet. In another embodiment, the signals received by the radio head are filtered using a plurality of filters to recover at least one data packet. In one embodiment, a controller coupled with the radio head filters the received signals and recovers the at least one data packet.

Abstract: A system and method are provided for performing stomp-and-restart techniques in distributed MU-MIMO system. A plurality of radio head devices are provided that are configured to be deployed separated from each other in a coverage region of interest of a wireless network. A central processor subsystem is provided that is in communication with the plurality of radio head devices. The central processor subsystem configured to perform several operations based on downconverted samples received from the plurality of radio head devices.

Abstract: Systems, methods, and computer program products to perform an operation comprising receiving, from a video monitoring system, a count of people detected at a first location, wherein the video monitoring system comprises a camera configured to capture video of the first location, receiving a count of wireless devices detected in a second location, and applying a first correction factor to the count of wireless devices detected at the second location to determine a number of people present in the second location, wherein the first correction factor is based on the count of people detected by the video monitoring system and a count of wireless devices in the first location.

Abstract: A wireless access point device wirelessly communicates with a plurality of wireless client devices. The wireless access point includes a central processor subsystem and a plurality of transceiver devices each including a plurality of antennas, and a plurality of radio transceivers, each of the plurality of transceiver devices configured for deployment throughout a coverage area, each transceiver device being connected to the central processor subsystem via a respective cable. The central processor subsystem distributes in-phase and quadrature baseband samples across the plurality of transceiver devices associated with traffic to be transmitted and received via the plurality of transceiver devices in one or more frequency bands so as to synthesize a wideband multiple-input multiple-output transmission channel and a wideband multiple-input multiple-output reception channel. The access point transmit and receive functions are “split” or partitioned across the plurality of transceivers devices.

Abstract: A system and method are provided for performing stomp-and-restart techniques in distributed MU-MIMO system. A plurality of radio head devices are provided that are configured to be deployed separated from each other in a coverage region of interest of a wireless network. A central processor subsystem is provided that is in communication with the plurality of radio head devices. The central processor subsystem configured to perform several operations based on downconverted samples received from the plurality of radio head devices.