HK40009176A - Methods and systems for cross bss sounding - Google Patents

Description

Method and system for cross-BSS sounding

Technical Field

Certain aspects of the present disclosure generally relate to transmission over a wireless medium with multiple access points. In particular, the present disclosure describes methods and systems for multi-user transmission that may be performed simultaneously by multiple access points.

Background

Many wireless networks utilize carrier sense multiple access with collision detection (CSMA/CD) to share the wireless medium. With CSMA/CD, prior to transmission of data on a wireless medium, a device may listen to the medium to determine whether another transmission is in progress. If the medium is idle, the device may attempt transmission. The device may also listen to the medium during its transmissions in order to detect whether data was successfully transmitted or whether a collision with another device's transmission may occur. Upon detecting a collision, the device may wait for a period of time and then re-attempt transmission. The use of CSMA/CD allows a single device to utilize a particular channel (such as a spatially multiplexed channel or a frequency division multiplexed channel) of a wireless network.

Users continue to demand greater and greater capabilities from their wireless networks. For example, video streaming over wireless networks is becoming more and more common. Video teleconferencing may also impose additional capacity requirements on wireless networks. In order to meet the bandwidth and capacity requirements demanded by users, improvements in the ability of wireless media to carry larger and larger amounts of data are required.

SUMMARY

Various implementations of the systems, methods, and devices of the present disclosure each have several aspects, not just any single one of which is relied upon to obtain the desired attributes described herein. Some prominent features are described herein, but they do not limit the scope of the disclosure.

The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description and the accompanying drawings. It should be noted that the relative dimensions of the following figures may not be drawn to scale.

One aspect is a method of sounding a wireless network. The method includes receiving, by an access point with a Basic Service Set (BSS), a first message comprising a beamforming report from a device not associated with the access point; and transmitting, by the access point, a message to the device based on the beamforming report.

Another aspect is an apparatus for sounding a wireless network. The apparatus includes an electronic hardware processor, an electronic hardware memory storing instructions that, when executed, cause the electronic hardware processor to: receiving, by an access point with a Basic Service Set (BSS), a first message comprising a beamforming report from a device that is not associated with the access point; and transmitting, by the access point, a message to the device based on the beamforming report.

Another aspect includes a non-transitory computer-readable medium comprising instructions that, when executed, cause an electronic hardware processor to perform a method of probing a wireless network, the method comprising: receiving, by an access point with a Basic Service Set (BSS), a first message comprising a beamforming report from a device that is not associated with the access point; and transmitting, by the access point, a message to the device based on the beamforming report.

Another aspect includes a method of sounding a wireless network. The method includes receiving, by a station, a sounding message from a first access point, wherein the station is associated with a second access point different from the first access point, generating, by the station, a beamforming report based on the sounding message, the beamforming report transmitted by the station over the wireless network.

Another aspect includes an apparatus for sounding a wireless network. The apparatus includes an electronic hardware processor, an electronic hardware memory storing instructions that, when executed, cause the electronic hardware processor to: the method generally includes receiving, by a station, a sounding message from a first access point, wherein the station is associated with a second access point different from the first access point, generating, by the station, a beamforming report based on the sounding message, and transmitting, by the station, the beamforming report over the wireless network.

Another disclosed aspect is a non-transitory computer-readable medium comprising instructions that, when executed, cause an electronic hardware processor to perform a method of probing a wireless network. The method includes receiving, by a station, a sounding message from a first access point, wherein the station is associated with a second access point different from the first access point, generating, by the station, a beamforming report based on the sounding message, the beamforming report transmitted by the station over the wireless network.

Another aspect disclosed is a method of sounding a wireless network. The method includes receiving, by a first access point, a first message comprising a beamforming report for a first station associated with the first access point, decoding the beamforming report to determine first station sounding information for a second access point; and transmitting the probe information to the second access point.

Another disclosed aspect is an apparatus for sounding a wireless network. The apparatus includes an electronic hardware processor, an electronic hardware memory operatively connected to the electronic hardware processor and storing instructions that, when executed by the electronic hardware processor, cause the electronic hardware processor to: receiving, by a first access point, a first message comprising a beamforming report for a first station associated with the first access point, the beamforming report decoded to determine first station sounding information for a second access point; and transmitting the probe information to the second access point.

Another disclosed aspect is a non-transitory computer-readable storage medium comprising instructions that, when executed, cause an electronic hardware processor to perform a method of probing a wireless network. The method includes receiving, by a first access point, a first message comprising a beamforming report for a first station associated with the first access point, decoding the beamforming report to determine first station sounding information for a second access point; and transmitting the probe information to the second access point.

Another disclosed aspect is a method of sounding a wireless network, comprising: receiving, by an access point having a basic service set, a sounding frame from a station outside the basic service set, generating a beamforming report for the station based on the sounding frame, and transmitting the beamforming report to a second access point.

Another disclosed aspect is an apparatus for sounding a wireless network. The apparatus includes an electronic hardware processor, an electronic hardware memory operatively connected to the electronic hardware processor and storing instructions that, when executed by the electronic hardware processor, cause the electronic hardware processor to: receiving, by an access point having a basic service set, a sounding frame from a station outside the basic service set, generating a beamforming report for the station based on the sounding frame, and transmitting the beamforming report to a second access point.

Another disclosed aspect is a non-transitory computer-readable storage medium comprising instructions that, when executed, cause an electronic hardware processor to perform a method of probing a wireless network. The method includes receiving, by an access point having a basic service set, a sounding frame from a station outside of the basic service set, generating a beamforming report for the station based on the sounding frame, and transmitting the beamforming report to a second access point.

Brief Description of Drawings

Fig. 1 is a diagram illustrating a multiple access Multiple Input Multiple Output (MIMO) system 100 with an AP and STAs.

Fig. 2 illustrates various components that may be employed in a wireless device 202 employed within the wireless communication system 100.

Fig. 3 shows four Basic Service Sets (BSSs), each BSS including an access point.

Fig. 4 illustrates three exemplary approaches for arbitrating wireless media with the communication system 300 of fig. 3.

Fig. 5 is a timing diagram illustrating messages exchanged between an access point and a plurality of stations.

Fig. 6 is another timing diagram illustrating messages exchanged between two access points and multiple stations.

Fig. 7 is another timing diagram illustrating messages exchanged between two access points and multiple stations.

Fig. 8 is another timing diagram illustrating messages exchanged between two access points and multiple stations.

Fig. 9 is another timing diagram illustrating messages exchanged between two access points and multiple stations.

Fig. 10 is a flow diagram of an exemplary method of sounding a wireless network.

Fig. 11 is a flow diagram of an exemplary method of sounding a wireless network.

Fig. 12 is a flow diagram of an example method of sounding a wireless network.

Fig. 13 is a flow diagram of an exemplary method of sounding a wireless network.

Detailed Description

Various aspects of the novel systems, devices, and methods are described more fully hereinafter with reference to the accompanying drawings. This summary disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein one skilled in the art should appreciate that the scope of the present disclosure is intended to cover any aspect of the novel systems, apparatuses, and methods disclosed herein, whether implemented independently or in combination with any other aspect of the present disclosure. Further, this scope is intended to cover such an apparatus or method as practiced using the other structures and functionality as set forth herein. It should be understood that any aspect disclosed herein may be implemented by one or more elements of the present disclosure.

Although specific aspects are described herein, numerous variations and permutations of these aspects fall within the scope of the present disclosure. Although some benefits and advantages of the preferred aspects are mentioned, the scope of the present disclosure is not intended to be limited to a particular benefit, use, or objective. Rather, aspects of the disclosure are intended to be broadly applicable to different wireless technologies, system configurations, networks, and transmission protocols, some of which are illustrated by way of example in the figures and the following description of the preferred aspects. The detailed description and drawings are merely illustrative of the disclosure rather than limiting.

The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. The following description is presented to enable any person skilled in the art to make and use the embodiments described herein. Details are set forth in the following description for purpose of explanation. It will be appreciated by one of ordinary skill in the art that the embodiments may be practiced without these specific details. In other instances, well-known structures and processes have not been described in detail so as not to obscure the description of the disclosed embodiments with unnecessary detail. Thus, the present application is not intended to be limited to the implementations shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

The radio access network technologies may include various types of Wireless Local Access Networks (WLANs). WLANs may be used to interconnect nearby devices together using widely used access networking protocols. The various aspects described herein may be applied to any communication standard, such as Wi-Fi, or more generally any member of the IEEE 802.11 family of wireless protocols.

In some implementations, a WLAN includes various devices that access a radio access network. For example, there may be: an access point ("AP") and a client (also referred to as a station or "STA"). Generally, the AP serves as a hub or base station for the STAs in the WLAN. The STAs may be laptop computers, Personal Digital Assistants (PDAs), mobile phones, etc. In an example, a STA connects to (e.g., "communicates with") an AP via a wireless link that conforms to Wi-Fi (e.g., an IEEE 802.11 protocol, such as 802.11ah) to obtain general connectivity to the internet or other wide area access network. In some implementations, the STA may also be used as an AP.

An access point ("AP") may include, be implemented as, or otherwise known as: a node B, a radio access network controller ("RNC"), an evolved node B ("eNB"), a base station controller ("BSC"), a base transceiver station ("BTS"), a base station ("BS"), a transceiver function ("TF"), a radio router, a radio transceiver, a basic service set ("BSs"), an extended service set ("ESS"), a radio base station ("RBS"), or some other terminology.

A station ("STA") may also include, be implemented as, or be referred to as: a user terminal, an access terminal ("AT"), a subscriber station, a subscriber unit, a mobile station, a remote terminal, a user agent, a user equipment, or some other terminology. In some implementations, an access terminal may comprise a cellular telephone, a cordless telephone, a session initiation protocol ("SIP") phone, a wireless local loop ("WLL") station, a personal digital assistant ("PDA"), a handheld device having wireless connection capability, or some other suitable processing device connected to a wireless modem. Accordingly, one or more aspects taught herein may be incorporated into a phone (e.g., a cellular phone or smart phone), a computer (e.g., a laptop), a portable communication device, a headset, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music or video device, or a satellite radio), a gaming device or system, a global positioning system device, a node B (base station), or any other suitable device configured to communicate via a wireless medium.

The techniques described herein may be used for various wireless communication networks such as Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, orthogonal FDMA (ofdma) networks, single carrier FDMA (SC-FDMA) networks, and the like. The terms "network" and "system" are often used interchangeably. A CDMA network may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), CDMA2000, and so on. UTRA includes wideband CDMA (W-CDMA) and Low Chip Rate (LCR). cdma2000 covers IS-2000, IS-95 and IS-856 standards. TDMA networks may implement radio technologies such as global system for mobile communications (GSM). OFDMA networks may implement radio technologies such as evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, Flash-OFDM, etc. UTRA, E-UTRA and GSM are part of the Universal Mobile Telecommunications System (UMTS). Long Term Evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents from an organization named "3 rd generation partnership project" (3 GPP). cdma2000 is described in a document from an organization named "third generation partnership project 2" (3GPP 2). These various radio technologies and standards are well known in the art.

Fig. 1 is a diagram illustrating a multiple access Multiple Input Multiple Output (MIMO) system 100 with an AP and STAs. For simplicity, only one AP 104 is shown in fig. 1. As described above, the AP 104 communicates with the STAs 106a-d (also referred to herein collectively as "STAs 106" or individually as "STAs 106") and may also be referred to as a base station or using some other terminology. As also described above, the STAs 106 may be fixed or mobile and may also be referred to as user terminals, mobile stations, wireless devices, or by some other terminology. The AP 104 may communicate with one or more STAs 106 on the downlink or uplink at any given moment. The downlink (i.e., forward link) is the communication link from the AP 104 to the STAs 106, and the uplink (i.e., reverse link) is the communication link from the STAs 106 to the AP 104. The STA 106 may also communicate peer-to-peer with another STA 106.

Portions of the following disclosure will describe STAs 106 that are capable of communicating via Spatial Division Multiple Access (SDMA). Thus, for such aspects, the AP 104 may be configured to communicate with both SDMA STAs and non-SDMA STAs. This approach may facilitate allowing older versions of STAs that do not support SDMA (e.g., "legacy" STAs) to remain deployed in the enterprise to extend their useful life, while allowing newer SDMA STAs to be introduced where deemed appropriate.

System 100 may employ multiple transmit antennas and multiple receive antennas for data transmission on the downlink and uplink. AP 104 is equipped with N_apMultiple antennas and represents Multiple Input (MI) for downlink transmission and Multiple Output (MO) for uplink transmission. The set of K selected STAs 106 collectively represents multiple outputs for downlink transmissions and multiple outputs for uplink transmissionsRepresenting multiple inputs. For pure SDMA, it is desirable to have N if the data symbol streams for the K STAs are not multiplexed in code, frequency, or time by some means_apK is more than or equal to 1. K may be greater than N if the data symbol streams can be multiplexed using TDMA techniques, using different code channels in CDMA, using disjoint sets of sub-bands in OFDM, etc_ap. Each selected STA may transmit and/or receive user-specific data to and/or from the AP. In general, each selected STA may be equipped with one or more antennas (i.e., N)_utNot less than 1). The K selected STAs may have the same number of antennas, or one or more STAs may have a different number of antennas.

SDMA system 100 may be a Time Division Duplex (TDD) system or a Frequency Division Duplex (FDD) system. For a TDD system, the downlink and uplink share the same frequency band. For FDD systems, the downlink and uplink use different frequency bands. MIMO system 100 may also utilize single carrier or multiple carrier transmissions. Each STA may be equipped with a single antenna (e.g., to keep costs down) or multiple antennas (e.g., where additional costs can be supported). The system 100 may also be a TDMA system if the STAs 106 share the same frequency channel by dividing transmission/reception into different time slots, where each time slot may be assigned to a different STA 106.

Fig. 2 illustrates various components that may be employed in a wireless device 202 employed within the wireless communication system 100. The wireless device 202 is an example of a device that may be configured to implement the various methods described herein. The wireless device 202 may implement the AP 104 or the STA 106.

The wireless device 202 may include an electronic hardware processor 204 that controls the operation of the wireless device 202. The processor 204 may also be referred to as a Central Processing Unit (CPU). Electronic hardware memory 206, which may include both read-only memory (ROM) and Random Access Memory (RAM), provides instructions and data to processor 204. A portion of the memory 206 may also include non-volatile random access memory (NVRAM). The processor 204 may perform logical and arithmetic operations based on program instructions stored within the memory 206. The instructions in the memory 206 may be executable to implement the methods described herein.

The processor 204 may comprise, or may be a component of, a processing system implemented with one or more electronic hardware processors. The one or more processors may be implemented with any combination of general purpose microprocessors, microcontrollers, Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (PLDs), controllers, state machines, gated logic, discrete hardware components, dedicated hardware finite state machines, or any other suitable entity capable of performing a calculus or other manipulation of information.

The processing system may also include a machine-readable medium for storing the software. Software should be construed broadly to mean any type of instructions, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The instructions may include code (e.g., in source code format, binary code format, executable code format, or any other suitable code format). The instructions, when executed by the one or more processors, cause the processing system to perform the various functions described herein.

The wireless device 202 may also include a housing 208, and the housing 208 may contain a transmitter 210 and a receiver 212 to allow transmission and reception of data between the wireless device 202 and a remote location. The transmitter 210 and receiver 212 may be combined into a transceiver 214. A single or multiple transceiver antennas 216 may be attached to the housing 208 and electrically coupled to the transceiver 214. The wireless device 202 may also include (not shown) multiple transmitters, multiple receivers, and multiple transceivers.

The wireless device 202 may also include a signal detector 218 that may be used in an effort to detect and quantify the level of signals received by the transceiver 214. The signal detector 218 may detect signals such as total energy, energy per subcarrier per symbol, power spectral density, and other signals. The wireless device 202 may also include a Digital Signal Processor (DSP)220 for use in processing signals. In some aspects, the wireless device may also include one or more of: a user interface component 222, a cellular modem 234, and a wireless lan (wlan) modem. The cellular modem may provide for communication using cellular technology such as CDMA, GPRS, GSM, UTMS, or other cellular networking technologies. WLAN modem 238 may provide communication using one or more WiFi technologies, such as any of the IEEE 802.11 protocol standards.

The various components of the wireless device 202 may be coupled together by a bus system 222, which bus system 222 may include a power bus, a control signal bus, and a status signal bus in addition to a data bus.

Certain aspects of the present disclosure support transmitting Uplink (UL) signals or Downlink (DL) signals between one or more STAs and an AP. In some embodiments, these signals may be transmitted in a multi-user MIMO (MU-MIMO) system. Alternatively, the signals may be transmitted in a multi-user FDMA (MU-FDMA) or similar FDMA system. In some aspects, the signals may be transmitted by one or more of the transmitter 210 and the WiFi modem 238.

Fig. 3 shows four Basic Service Sets (BSSs) 302a-d, each BSS including an access point 104a-d, respectively. Each access point 104a-d is associated with at least two stations within its respective BSS 302 a-d. The AP 104a associates with the STAs 106 a-b. The AP 104b is associated with the STAs 106 c-d. The AP 104c is associated with STAs 106 e-f. The AP 104d is associated with STAs 106 g-h. The AP associated with a STA may be referred to throughout this disclosure as a BSS AP for the STA. Similarly, an AP that is not associated with a particular STA may be referred to throughout this disclosure as an OBSS AP for the STA. The tetris association between an AP and one or more stations provides, in part, coordination of communications between devices within a Basic Service Set (BSS) defined by the AP and its associated STAs. For example, devices within each BSS may exchange signals with each other. These signals may be used to coordinate transmissions from the respective APs 104a-d and stations within the APs' BSSs 302 a-d. As will be appreciated by one of ordinary skill in the art, client devices (e.g., STAs) may "associate" with a BSS belonging to an AP. As one of ordinary skill in the art will further appreciate, a STA may "connect" to or "communicate" with another device (e.g., an AP) in any number of ways, without having to formally "associate" with the AP, e.g., by sending messages to the AP, by receiving messages from the AP, etc., as may be described in one or more standards (e.g., 802.11).

The devices shown in fig. 3, which include APs 104a-d and STAs 106a-h, also share the wireless medium. In some aspects, sharing of the wireless medium is facilitated via use of carrier sense multiple access with collision detection (CSMA/CD). The disclosed embodiments may provide a modified version of CSMA/CD that provides an increase in the ability of BSSs 302a-d to communicate simultaneously as compared to known systems.

Stations 106a-h within BSSs 302a-d may have different capabilities to receive transmissions from their associated APs based, at least in part, on their location relative to other APs and/or stations that are outside of their respective BSSs (obss). For example, because stations 106a, 106d, 106e, and 106h are located relatively far from the OBSS AP, these stations may have the capability to receive transmissions from their BSS AP even though the OBSS AP or STA is transmitting. Stations with such reception characteristics may be referred to as reuse STAs throughout this disclosure.

In contrast, STAs 106b, 106c, 106f, and 106g are illustrated in locations relatively close to the OBSS AP. Thus, these stations may have a weaker ability to receive transmissions from their BSS AP during transmissions from the OBSS AP and/or OBSS STAs. Stations with such reception characteristics may be referred to throughout this disclosure as non-reuse or edge STAs. In some aspects, the disclosed methods and systems may provide improved capabilities for non-reuse STAs to concurrently communicate while other OBSS devices are also communicating over the wireless medium.

In at least some of the disclosed aspects, two or more of the APs 104a-d may negotiate to form an access point cluster. In other aspects, the cluster configuration may be defined via manual configuration. For example, each AP may maintain configuration parameters that indicate whether the AP is part of one or more clusters and if so, the APs may also maintain a cluster identifier for the cluster. In some aspects, the cluster configuration may also indicate whether the AP is a cluster controller for the cluster. In some embodiments disclosed herein, a cluster controller may perform different functions than an AP that is part of a cluster but is not a cluster controller. Thus, in some aspects, two or more of the APs 104a-d may be included in the same cluster. STAs associated with these APs included in the cluster may also be considered to be included in the cluster of their associated APs. Thus, because in some aspects two or more of the APs 104a-d may be included in the same cluster, in some aspects STAs a-h may also be included in the same cluster.

Thus, according to the above features, two or more APs may collect information about their neighbors (e.g., network, channel conditions, BSS, traffic patterns, etc.) and coordinate to form a cluster. As described above, the cluster may further include one, more, or all of the STAs connected and/or associated with the AP. In some aspects, an external entity (e.g., a controller or "cluster controller") may facilitate forming a cluster. In some embodiments, one of the APs may act as a cluster controller.

In some aspects, the APs in a cluster may be configured to account for certain security considerations among the cluster. For example, the APs 104a-d may all be physically located at a particular site or location. For example, the APs 104a-c may all be members of a first operator (e.g., a first Mobile network operator, such as T-Mobile), and the AP 104D may be a member of a second operator (e.g., a second Mobile network operator, such as Verizon). In some aspects, an AP may determine whether to protect (e.g., via encryption) one or more communications between an AP belonging to a first operator and an AP belonging to a second operator. Based on the determinations and features described herein, the APs 104a-d may thus form a cluster, regardless of whether all of the APs in the cluster are members of the same operator.

In some aspects, APs in a cluster may coordinate transmissions between themselves and their associated APs and/or STAs. In some aspects, the cluster identifier may uniquely identify a group of access points in the cluster. In some aspects, a cluster identifier may be transmitted to a station, e.g., in a frame, during association of the station with any AP in the cluster. In an aspect, the frame may be a management frame, such as an association response frame, a probe response frame, a beacon frame, and/or the like. The station may then utilize the cluster identifier to coordinate communications within the cluster. For example, one or more messages transmitted over the wireless network may include the cluster identifier, which the recipient STA may use to determine whether the message is addressed to the STA or not addressed to the STA.

On the other hand, during association, a list of APs in the cluster may be provided to the station. The list of APs may identify the APs from a Media Access Control (MAC) address. The station may receive the list over the wireless network, e.g., via advertisements in beacons from one or more APs, advertisements in different types of management frames (e.g., probe response frames or association response frames), etc. The station may then utilize the list of APs to coordinate communications within the cluster. As a non-limiting example, the STA may utilize a list of APs to: identify the OBSS AP belonging to the cluster, determine which frames from the OBSS AP to decode (if any), determine which frames from the OBSS AP to drop (if any), or some combination of the above.

In some implementations, the AP may assign a unique cluster STA identifier to the STA when the STA associates with the AP. Such cluster STA identifiers may be unique to each STA belonging to a cluster. In an aspect, each AP may share and coordinate the cluster STA identifiers such that no two STAs in the cluster have the same cluster STA identifier. In this case, the OBSS AP may address the non-associated stations according to the cluster STA identifier assigned to the non-associated stations (e.g., stations not associated with the OBSS AP). It should be understood that such features may be incorporated into any number of combinations. As some non-limiting examples, a frame may include: a cluster STA identifier and a cluster ID, a cluster STA identifier but not a cluster ID, a cluster ID but not a cluster STA identifier, etc. In instances where a frame includes both a cluster STA identifier and a cluster ID, in one example, an STA receiving the frame may thus be informed that the frame is from an OBSS AP and that the frame is related to distributed (e.g., or "federated") MIMO communications.

In other implementations, one or more APs in the cluster may share a MAC address for their respective associated STAs. For example, AP 104a may be part of a cluster that also includes APs 104 b-d. AP 104a may be associated with stations 106a and 106 b. In this example, APs 104b-d are not associated (or "unassociated") with either station 106a or station 106b (e.g., APs 104b-d are "OBSS APs" from the perspective of station 106a and station 106 b). In this example, the AP 104a may thus share the identifiers of the stations 106a and 106b in the cluster. For example, the identifier may include a cluster STA identifier for each of the stations 106a and 106 b. The cluster STA identifiers for stations 106a and 106b may include the MAC addresses of stations 106a and 106b, respectively. In response to AP 104a sharing such an identifier, APs 104b-d (OBSS APs in this example) may be allowed to send directional frames to one or both of stations 106a and 106 b.

In some embodiments, instead of the cluster identifier described above, a list of APs described above (e.g., to identify the cluster) may be utilized. In some embodiments, the cluster identifier described above (e.g., to identify the cluster) may be utilized instead of the list of APs described above. In some embodiments, both the list of APs and the cluster identifier may or may not be used, for example, to identify the cluster. Thus, different or alternative approaches described herein may be used to identify clusters.

In any case, via the use of one or more of such cluster identifications (e.g., cluster identifier, AP list, distribution of one or more cluster STA identifiers), a non-AP STA (e.g., STA 106a) may decode and respond to a particular frame sent by an OBSS AP (e.g., AP 104d) belonging to the cluster. Further, the STA 106a may be configured to discard (e.g., ignore) frames from APs not belonging to the cluster.

The cluster of access points of various embodiments may also utilize various methods to identify STAs within the cluster. For example, since known methods of generating Association Identifiers (AIDs) may not provide uniqueness across access points, in some aspects stations may be identified with Media Access Control (MAC) addresses when appropriate. For example, in the disclosed embodiment, a known message including a user information field identifying a station with an association identifier may be modified to contain data derived from the station's MAC address. Alternatively, the method of generating the association identifier may be modified to ensure uniqueness within the access point cluster. For example, a portion of the association identifier may uniquely identify an access point within the cluster. Stations associated with the access point will be assigned an association identifier that includes a unique identification. This provides a unique association identifier across access points within the cluster. In some other aspects, the association identifier within the cluster may comprise a cluster identifier. This may provide uniqueness across clusters to facilitate future cross-cluster coordination of communications.

Fig. 4 illustrates three exemplary approaches for arbitrating wireless media with the communication system 300 of fig. 3. The approach 405 utilizes Carrier Sense Medium Access (CSMA) to perform single BSS multi-user transmission. For example, each of the transmissions 420a-d may be performed by the BSS 302a-d of fig. 3, respectively. The use of conventional CSMA in the approach 405 causes the medium to be used by only one BSS at any point in time.

The media arbitration method 410 utilizes coordinated beamforming. Through coordinated beamforming 410, the APs 104a-d may coordinate transmissions between their respective BSSs. In some aspects, the coordination may be performed over a wireless medium, or in some aspects over a backhaul network. In these aspects, coordinating traffic over the backhaul network provides improved utilization of the wireless medium.

By this approach, reuse STAs of different BSSs may be scheduled to concurrently transmit or receive data. For example, the relative length of the communication channel between the STA 106a and the AP 104a may allow the two devices to exchange data while communicating with OBSS devices (such as, for example, the AP 104b and the STA 106 d). Additionally, approach 410 allows non-reused STAs to be scheduled to transmit concurrently with OBSS devices. For example, simultaneous communication may be scheduled between STA 106b within BSS 302 and AP 104d and STA 106h of BSS 302 d. Simultaneous communication between a non-reusing STA (such as STA 106b) and, for example, AP 104d may be facilitated by scheduling AP 104d to transmit signals to STA 106b simultaneously with AP 104 d-to-STA 106h transmissions. For example, the AP 104d may transmit a null signal that dominates the interfering signal to the STA 106 b. Thus, while transmitting the first signal to the STA 106h, the AP 104d may simultaneously transmit a signal to the STA 106b that cancels the first signal. Such simultaneous transmissions by the AP 104 may be provided by selecting, for each of the transmissions, an individual antenna of a plurality of antennas provided by the AP 104 d.

The arbitration scheme 415 illustrates an exemplary joint multi-user communication or distributed MIMO communication across access points 104a-d within BSSs 302 a-d. By this approach, an AP cluster (such as APs 104a-d) may simultaneously serve N1-SS STAs, where N is about 3/4 of the total number of antennas across all APs within the cluster. Distributed MIMO communications may coordinate sets of antennas across multiple APs within a cluster to transmit to stations within the cluster. Thus, while conventional MIMO methods allocate transmit antennas within a single BSS to stations within the BSS, distributed MIMO allows for the allocation of transmit antennas outside the BSS to facilitate communication with stations within the BSS.

In distributed MIMO communications, a station in one BSS may communicate with one or more access points in a different BSS. Thus, for example, station 106a of BSS 302a of fig. 3 may communicate with access point 104d in BSS 302 d. This communication may occur simultaneously with the communication between the STA 106a and the AP 104a (i.e., the BSS AP of the STA 106 a). In some aspects of uplink distributed MIMO communications, the STA 106a may engage in one or more uplink communications to the AP 104a simultaneously with the AP 104 d. Alternatively, downlink distributed MIMO communication may include the AP 104a transmitting data to the STA 106a simultaneously with the transmission from the AP 104d to the STA 106 a.

Thus, one or more of the distributed embodiments may utilize coordinated multipoint (CoMP, also referred to as, e.g., network MIMO (N-MIMO), distributed MIMO (D-MIMO), or coordinated MIMO (Co-MIMO), etc.) transmission forms of MIMO in which multiple access points maintaining multiple corresponding basic service sets may engage in respective coordinated or joint communications with one or more STAs 106. CoMP communication between a STA and an AP may utilize, for example, a joint processing scheme in which an access point associated with one station (BSS AP) and an access point not associated with one station (OBSS AP) cooperate to participate in transmitting downlink data to the STA and/or jointly receive uplink data from the STA. Additionally or alternatively, CoMP communications between the STA and multiple access points may utilize coordinated beamforming, where the BSS AP and OBSS AP may cooperate to cause the OBSS AP to form a spatial bundle for transmission away from the BSS AP and, in some aspects, away from at least a portion of its associated stations, thereby enabling the BSS AP to communicate with one or more of its associated stations with reduced interference.

To facilitate the coordinated beamforming approach 410 or the joint MIMO approach 415, an understanding of the channel conditions between the access point and the OBSS device may provide for greater wireless communication efficiency.

Fig. 5 is a timing diagram illustrating messages exchanged between an access point and a plurality of stations. Fig. 5 shows the access points 104a-b and their associated stations STAs 106a-b and 106c-d and BSSs 302a-b illustrated in fig. 3. Although fig. 5 illustrates an exchange of wireless messages between a single access point 104a and multiple stations 106a-d, those skilled in the art will appreciate that similar exchanges may be performed by any number of additional access points, such as AP 104 b.

Fig. 5 shows the AP 104a transmitting a sounding announcement message 502. The sounding announcement message indicates that a sounding frame is to be transmitted and provides other devices with an opportunity to be ready to receive the sounding frame over the wireless medium and collects information about the channel conditions between the AP 104 and the recipient device. In some aspects, the sounding announcement message may be ｃA null datｃA packet announcement message (NDP- ｃA). In some aspects, the sounding announcement message 502 may include one or more of the following: a cluster identifier, a list of Basic Service Set Identifiers (BSSIDs) to which the probe-on message relates (e.g., BSSIDs of APs included in the cluster), or a transmitter address (address of the device that transmitted the probe-on announcement message 502). In some aspects, the information may allow a device receiving the sounding announcement message to determine whether the sounding announcement message is for a cluster in which the recipient device is included. For example, STAs within a cluster may be provided with a cluster identifier during association of the STA with its access point. Thus, when a STA receives a sounding announcement message 502 that includes a cluster identifier, the STA may determine whether it should be ready to measure channel characteristics based on the sounding frame 504, as discussed below. In some aspects, the transmission address of the sounding announcement message may be a medium access control address or a station address of the AP transmitting the sounding announcement message. The station address may also be the BSSID of the AP. If an AP is included in a cluster, stations in the cluster may have a list of BSSIDs of APs included in the cluster. The STA may have received this information during association with its AP. The station may then identify whether the sounding announcement message including the station address of the AP is from an AP within the STA cluster.

The AP 104a then transmits a sounding frame 504. In some aspects, the sounding frame 504 may be a Null Data Packet (NDP). Each of the STAs 106a-b and 106c-d may receive a sounding frame 504. Based on their reception of the sounding frame 504, one or more of the STAs 106a-b and/or 106c-d may determine channel conditions between the AP 104a and the receiving STA. In some aspects, the sounding frame 504 identifies a cluster identifier of a cluster including AP 104a and AP 104b, e.g., via a field in the sounding frame. Each of the STAs 106a-d may also be aware of the cluster in which they operate. For example, as previously described, the STAs 106a-d may receive the cluster identifier as part of an association procedure with their respective BSS AP. Alternatively, the sounding frame 504 may identify a transmitter address of the device transmitting the sounding frame, which in some aspects is equivalent to a BSSID of the access point transmitting the sounding frame 504. In some aspects, the receiver station may utilize the transmitter address to determine whether the sounding frame should be reacted to. In other embodiments, sounding frame 504 may include a list of BSSIDs of access points included in the cluster. The station may also know its own BSSID, e.g., as a result of an association procedure with its home access point. The station may then compare the list of BSSIDs in the sounding frame with its own BSSID to determine whether the sounding frame is suitable for the station.

In some other aspects, AP 104a and AP 104b may maintain a list of bss (bssid) identifiers for APs within a cluster that includes AP 104a and AP 104 b. The STAs 106a-d may decode the received packet to determine whether the received packet is from a device within the cluster by comparing the BSSID included in the packet to a list of BSSIDs. In some of these embodiments, sounding frame 504 may include a list of BSSIDs of APs within the cluster.

The AP 104a then transmits a trigger message 506. The trigger message 506 is configured to indicate to the stations 106a-d that they should transmit a beamforming report to the AP 104 a. Upon receiving the trigger frame 506, each of the stations 106a-d transmits a beamforming report 510a-d, respectively. In some embodiments, a message (e.g., a "frame," "trigger frame," "first message," "first frame," first trigger frame, etc.) may be transmitted from a component of a cluster (e.g., from one of a plurality of access points, or from one of a plurality of stations). As one example, the trigger frame 506 may be transmitted from one AP to multiple APs. In some aspects, as shown, beamforming reports 510a-d collectively form an uplink OFDMA transmission to AP 104 a. In other aspects, the individual beamforming reports 510a-d may be separately communicated to the AP 104a as separate single user transmissions. The beamforming reports received by the AP 104a may provide an indication of channel conditions, such as a path loss or Received Signal Strength Indication (RSSI) between the AP 104a and each of the individual stations 106 a-d. These indications of channel conditions may be used to perform the coordinated beamforming and/or joint MIMO arbitration methods described above with reference to fig. 3. As described herein, a trigger frame (e.g., trigger frame 506) may be an extension of a frame described in a particular standard (e.g., a "trigger frame" (e.g., for addressing multiple STAs) described in IEEE 802.11 ax). In an exemplary implementation, the trigger frame may be used to address multiple STAs. In alternative and/or subsequent implementations, the trigger frame 506 may be a frame or an extension of a frame described in one or more subsequent standards (e.g., for addressing multiple APs).

To facilitate multi-user uplink of beamforming reports 510a-d, trigger 506 may be generated by AP 104a to include a cluster identifier of the APs within the cluster (including AP 104a and AP 104 b). Alternatively, the trigger frame may include a list of BSSIDs of APs within the cluster. This information allows the recipient devices to determine whether they are addressed by the trigger frame 506. In some aspects, a device may be configured to continuously monitor transmissions of OBSS devices in order to detect, for example, sounding announcement frame 502 and/or sounding frame 504. In some other aspects, the APs within the cluster may coordinate the sounding process. In response to the coordination, the AP may send a signal to devices within its BSS to cause the sounding process to start within a time period. The signal may selectively enable devices within the BSS to begin monitoring OBSS traffic.

Fig. 6 is another timing diagram illustrating messages exchanged between two access points and multiple stations. Fig. 6 shows the access points 104a-b and their associated stations STAs 106a-b and 106c-d and BSSs 302a-b illustrated in fig. 3. Fig. 6 shows the AP 104a transmitting a sounding announcement message 602. The sounding announcement message 602 indicates that one or more sounding frames, such as sounding frames 604a-b, may be transmitted. The sounding announcement message 602 may indicate, e.g., via fields set to one or more predetermined values, which APs to generate sounding messages in response to the sounding announcement message 602. For example, in some aspects, the sounding announcement message may include the BSSID of the AP that is to send the sounding message in response to the sounding announcement message 602.

The sounding announcement message 602 may also provide other devices on the wireless medium with an opportunity to be ready to receive sounding frames and collect information about channel conditions between the transmitter (e.g., APs 104a-b) of the sounding frames and the recipient devices. In some aspects, the sounding announcement message 602 may be ｃA null datｃA packet announcement message (NDP- ｃA).

The AP 104a then transmits a sounding frame 604 a. In some aspects, the sounding frame 604a may be a Null Data Packet (NDP). Each of the STAs 106a-b and 106c-d may receive the sounding frame 604 a. Based on their reception of the sounding frame 604a, one or more of the STAs 106a-b and/or 106c-d may determine channel conditions between the AP 104a and the receiving STA. AP 104b transmits a sounding message 604b in response to the sounding announcement message 602 transmitted by AP 104 a. Each of the STAs 106a-b and 106c-d may receive the sounding frame 604 b. Based on their receipt of the sounding frame 604b, one or more of the STAs 106a-b and/or 106c-d may determine channel conditions between the AP 104b and the receiving STA.

The AP 104a then transmits a trigger message 606 a. The trigger message 606a is configured to indicate to the stations 106a-b within the same BSS as the AP 104a transmitting the trigger that they should transmit a beamforming report to the AP 104 a. Upon receiving the trigger frame 606a, each of the stations 106a-b transmits an individual beamforming report 610a-b, respectively. In some aspects, as shown, beamforming reports 610a-b collectively form an uplink OFDMA transmission to AP 104 a. In other aspects, the individual beamforming reports 610a-b may be separately transmitted to the AP 104 a. The beamforming reports received by the AP 104a may provide an indication of channel conditions between the AP 104a and each of the individual stations 106 a-b. The beamforming reports 610a-b may also provide an indication of channel conditions between the AP 104b and each of the individual stations 106 a-b. In some aspects, the beamforming reports 610a-b may include sounding information for all APs within a cluster. These indications of channel conditions may be used to perform the coordinated beamforming and/or joint MIMO arbitration methods described above with reference to fig. 3. The AP 104a may transmit at least some portions of the beamforming reports 610a-b to other access points. For example, in some aspects, beamforming information related to a path between a station STA 106a or 106b and an AP 104b (which may be included in a beamforming report 610a or 610 b) may be transmitted by the AP 104a to the AP 104 b. This transmission is not illustrated in fig. 6.

AP 104b transmits a trigger message 606 b. The trigger message 606b is configured to indicate to stations 106c-d within the same BSS as the AP 104b transmitting the trigger that they should transmit a beamforming report to the AP 104 b. The trigger message 606b may indicate which stations are to respond to it in several ways. For example, the trigger message 606b may identify the AP 104 b. In some embodiments, because AP 104b is within the same BSS as stations 106c-d, each station may respond based on this equal BSS. In other embodiments, the trigger message 606b may explicitly list the stations to respond to the trigger message. For example, a list of media access control addresses or association identifiers may be provided in the trigger message.

Upon receiving trigger frame 606b, each of stations 106c-d transmits an individual beamforming report 610c-d, respectively. In some aspects, as shown, beamforming reports 610c-d collectively form an uplink OFDMA transmission to AP 104 b. In other aspects, individual beamforming reports 610c-b may be separately communicated to the AP 104 b. The beamforming reports received by the AP 104b may provide an indication of channel conditions between the AP 104b and each of the individual stations 106 c-d. The beamforming reports 610c-d may also provide an indication of channel conditions between the AP 104a and each of the individual stations 106 c-d. These indications of channel conditions may be used to perform the coordinated beamforming and/or joint MIMO arbitration methods described above with reference to fig. 3.

To implement the sounding procedure described in fig. 6, in some aspects, the sounding announcement message 602 may identify which stations outside the AP 104a BSS (i.e., outside the BSS 302a of fig. 3) are to determine sounding information based on the sounding frame 604a transmitted in response to the sounding announcement message 602. Further, to ensure uniqueness of the identifiers of the various stations across multiple BSSs, one or more of the trigger frames 606a-b and the beamforming reports 610a-b may identify the stations with their MAC addresses. For example, the trigger frame 606a may indicate via the MAC addresses of the stations 106a-b that the stations should transmit beamforming reports 610 a-b. Similarly, trigger frame 606b may indicate via the MAC addresses of stations 160c-d that these stations are to transmit beamforming reports 610 c-d. Each of beamforming reports 610a-d may identify the respective stations to which they apply based on their MAC addresses.

In some aspects, the transmission of the sounding announcement message 602 by the AP 104a is coordinated with the AP 104 b. For example, the APs 104a-b may negotiate to determine a time for transmission of the sounding announcement message 602 and transmission of another sounding announcement message (not shown) that may be transmitted by the AP 104 b. Those skilled in the art will appreciate that the description of fig. 6 is exemplary for the AP 104a, and that the described process may also be used to enable the AP 104b to collect beamforming reports from the STAs 106 a-d.

Fig. 7 is another timing diagram illustrating messages exchanged between two access points and multiple stations. Fig. 7 shows the access points 104a-b and their associated stations STAs 106a-b and 106c-d and BSSs 302a-b illustrated in fig. 3. The timing diagram operates similarly to the timing diagram of fig. 6, except that the AP 104a transmits a single trigger frame 708 indicating that stations within both BSS 302a and BSS 302b (shown in fig. 7 as example stations STA 106a-b and STA 106c-d, respectively) should transmit their beamforming reports to the AP 104 a. In some aspects, as shown, beamforming reports 710a-d may be transmitted by STAs 106a-d, respectively, as part of a multi-user uplink transmission to AP 104 a. In some other aspects, one or more of the individual beamforming reports 710a-d may be transmitted to the AP 104a as a single user message.

Thus, in response to the trigger frame 708, the STAs 106a-d transmit their beamforming reports 710a-d to the AP 104 a. As described above with reference to fig. 6, the beamforming reports include sounding information for channel conditions between the respective STA and both the AP 104a and the AP 104b based on the sounding frames 704a-b, respectively. In some aspects, the AP 104a may share information contained in the beamforming reports 710a-d with the AP 104b, e.g., via a backhaul network communication channel.

To implement the sounding procedure illustrated in fig. 7, the STAs 106c-d may be configured to receive and process a sounding announcement message 702, a sounding frame 704a, and a trigger frame 708, which are transmitted by the AP 104a outside of the BSS of the STAs 106 c-d.

Fig. 8 is another timing diagram illustrating messages exchanged between two access points and multiple stations. Fig. 8 shows the access points 104a-b and their associated stations STAs 106a-b and 106c-d and BSSs 302a-b illustrated in fig. 3. The timing diagram operates similarly to the timing diagram of fig. 7, except that sounding frames 804a-b are transmitted simultaneously by APs 104a-b as part of a joint MIMO transmission. In some aspects, the APs 104a-b may transmit two NDP frames using interleaved tones or Q matrices in some aspects.

In some aspects, the APs 104a-b may synchronize transmission of sounding frames 804a-b based on transmission of the sounding announcement frame 802. For example, the APs 104a-b may be configured to transmit the sounding frames 804a-b a short interframe space (SIFS) time after the transmission of the sounding announcement frame 802. More specifically, the APs 104a-b may transmit Null Data Packet (NDP) frames simultaneously. In some aspects, the NDP frames from each AP may be separated in the frequency domain and/or the spatial domain using interleaved tones and/or Q matrices.

Fig. 9 is another timing diagram illustrating messages exchanged between two access points and multiple stations. Fig. 9 shows the access points 104a-b and their associated stations STAs 106a-b and 106c-d and BSSs 302a-b illustrated in fig. 3. The timing diagram of fig. 9 is used to provide the AP 104a with sounding information for communication paths between at least some stations within the BSS of the AP 104a (e.g., BSS 302a of fig. 3) and two or more access points, such as APs 104 a-b.

Fig. 9 illustrates the AP 104a transmitting a sounding trigger frame 902. The sounding trigger frame indicates, e.g., via a field having a predetermined value, that one or more stations within the AP 104a BSS (e.g., BSS 302a of fig. 3) should send sounding frames 904 a-c. In some aspects, the trigger frame 902 identifies a station to transmit a sounding frame. In some aspects, a station may be indicated via a list of association identifiers or Medium Access Control (MAC) addresses in a trigger frame.

In some aspects, AP 104a and AP 104b (and in some aspects, additional access points) may coordinate the timing of the sounding trigger 902. For example, the APs may coordinate timing such that individual probe passes initiated by two or more APs do not overlap.

In some aspects, the AP 104 determines the STA to which the sounding trigger 902 is addressed based on the STA's characteristics as a reused or non-reused STA. For example, in some aspects, the path loss or signal strength of a communication path between the AP 104 and the STA may determine, at least in part, whether the STA reuses the STA or is a non-reusing STA. For example, if the path loss is greater than a threshold, the STA may be a non-reuse STA.

Upon receiving the sounding trigger 902, the addressed STA may transmit a sounding frame. Fig. 9 illustrates STA 106b being addressed by a sounding trigger 902 and responding by transmitting a sounding frame 906. In some aspects, as illustrated, the sounding frame 906 may be a null data frame or packet (NDP).

Based on the reception of the sounding frame 906, each of the APs 104a-b may determine one or more characteristics of a communication path between the STA 106 and the AP 104a and/or the AP 104 b. The AP 104b may communicate this information to the AP 104a in a beamforming report 914. In some aspects, the information may be communicated between two or more access points over a backhaul network.

Fig. 10 is a flow diagram of an exemplary method of sounding a wireless network. In some aspects, process 1000 discussed below with respect to fig. 10 may be performed by device 202. For example, in some aspects, instructions stored in the memory 206 may configure the hardware processor 204 to perform one or more of the functions discussed below.

Process 1000, discussed below with respect to fig. 10, allows for the collection of information regarding communication paths between an access point and one or more stations that may not be associated with the access point. In other words, the access point and the station may be in different basic service sets. The information about the communication path may include one or more of: channel coefficients, path loss information, and RSSI indications, along with possibly other information that can assist a transmitting device in determining how best to transmit a signal over a communication path to a destination device to provide enhanced quality of the signal when received by the device.

As described above, information on a communication path between non-associated devices may be utilized when performing joint MIMO communication, utilizing multiple BSSs for simultaneous transmission on a single channel. Since signals from multiple BSSs interfere with each other, the information about the communication paths can enable transmitting devices within multiple BSSs to customize their transmission signals to reduce such interference in some scenarios. Information about the communication path may also be used for coordinated beamforming transmission. Such transmissions may include transmissions of an interference blanking signal, the interference being caused by a second signal that is also simultaneously transmitted. The blanking signal may reduce interference caused by the second signal at the device.

In some aspects, process 1000, discussed below with reference to fig. 10, may be used by an access point to facilitate collection of sounding information for communication paths between stations within a cluster of access points and the access points within the cluster. The access point may transmit a sounding frame to at least the OBSS stations, which sounding frame is utilized by the OBSS stations to characterize a communication path between the access point and the receiver station. The access point may then request that its or all stations report their sounding information to the access point itself or to their BSS access point. In some aspects, the access point performing process 1000 does not request to transmit sounding information. Instead, another access point in the cluster may do so.

At block 1010, a first message is received by a first access point. The first access point may coordinate communication for a basic service set. The first access point may be associated with one or more stations. The first message is received from a first station outside the basic service set. In other words, the first station is not associated with the first access point (e.g., an association procedure has not been performed in which the first station and the access point exchange association messages, such as an exchange of association request/response messages). The first message includes a beamforming report of the OBSS first station. The beamforming report may include information related to channel conditions between the OBSS first station and the access point.

At block 1020, a second message is transmitted to the OBSS first station based on the beamforming report. In some aspects, the OBSS first station may be a station associated with an access point different from the first access point. In some aspects, the second message may be configured to null interference caused by the first access point transmitting the third message to devices within the BSS of the first access point. For example, as described above with reference to fig. 3, an OBSS device may be a non-reuse station associated with a different access point. In the case where the second access point transmits to at least the first device and the first access point transmits to the first device (OBSS) and a third device (BSS) device, the beamforming report of the OBSS device may allow the first access point to coordinate simultaneous transmissions with the second access point.

Some aspects of process 1000 include transmitting a beamforming trigger message to a first station. The beamforming trigger message may be generated by the first access point to indicate, for example, via a field having a predetermined value: the first station, and in some aspects other stations outside of the first access point BSS, are to transmit their beamforming reports to the first access point upon receiving the trigger message. In some aspects, the first access point transmits a sounding frame prior to transmission of the trigger message. In some aspects, the beamforming trigger message is transmitted in response to transmission of a sounding frame because it stimulates the recipient device to collect beamforming information due to analysis of the sounding frame. In some aspects, the sounding frame is a null data packet or frame (NDP). However, a sounding frame may be any frame configured to provide a test frame to a receiving device to measure one or more characteristics of a communication path between a transmitter and a receiver of the frame.

The sounding frame may be used by the first station to determine one or more characteristics of a communication path between the first access point and the first station. The characteristics may include one or more of: channel coefficients, a path loss indication, and a Received Signal Strength Indication (RSSI) associated with the channel. The communication path may be a particular channel of the wireless medium (such as a particular spatial channel or frequency channel). The particular channel may be used by both the first access point and the second access point for simultaneous transmission, as described above.

In some aspects, the first access point may transmit a sounding announcement message prior to transmission of the sounding frame. The sounding announcement message may indicate, for example, via a field set to a predetermined value: the receiving device should be ready to receive the probe-through message and, upon receipt of the probe-through message, characterize a communication path from the transmitting first access point to the receiving device.

In some aspects, the first access point and the second access point are preconfigured to be part of a cluster of access points. Alternatively, the formation of the cluster may be dynamically achieved via an electronic message exchange between the first access point and the second access point. The cluster may be assigned an identifier. The identifier may be distributed to various stations associated with the first access point, e.g., via an association process that includes an association request/response message exchange. Alternatively, the association process may communicate the cluster information to the associated stations by transmitting a list of one or more BSSIDs of APs within the cluster as part of the association process, e.g., in a management frame (e.g., an association response frame) transmitted from the first access point to the one or more associated stations.

In some aspects, the generation of the association identifier for the station associated with the first access point may include a portion of the association identifier that is unique across access points within the cluster. This may ensure that stations within a cluster each have a unique association identifier.

In some aspects, the sounding frame is generated by the first access point to include an indication of the cluster. In some aspects, the indication may be a cluster identifier. Alternatively, the indication may include one or more BSSIDs of APs included in the cluster. This may allow devices receiving the sounding frame to determine whether they are included in the cluster identified by the sounding frame and generate communication channel statistics when appropriate.

In some aspects of process 1000, the first access point receives a second beamforming report from a second device outside of the basic service set. The device may be an OBSS station. In some aspects, the first beamforming report and the second beamforming report may be transmitted to the first access point as part of a multi-user uplink communication.

In some aspects of process 1000, the beamforming report identifies the first station via a Media Access Control (MAC) address of the first station. For example, the multi-user uplink communication may include a per-user information field for each device participating in the multi-user uplink. Existing implementations of this field may utilize an association identifier to identify the devices participating in the communication. These existing association identifiers may not be unique across access points and their associated stations within a cluster. Thus, it may be preferable to use a Medium Access Control (MAC) address to identify a station, although it has an increased length relative to the known format of the association identifier. Alternatively, some aspects may utilize one of the disclosed methods of generating an association identifier that is unique within a cluster of access points. In these aspects, the per-user information field of the multi-user uplink transmission may identify stations participating in the uplink communication via a new form of association identifier.

Another disclosed aspect is a non-transitory computer-readable storage medium comprising instructions that, when executed, cause an electronic hardware processor to perform a method of probing a wireless network. The method includes receiving, by a first access point, a first message comprising a beamforming report for a first station associated with the first access point, decoding the beamforming report to determine first station sounding information for a second access point; and transmitting the probe information to the second access point.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: negotiating with a second access point to form a cluster comprising the first access point and the second access point; assigning a cluster identifier to the cluster; associating with the second station based on the cluster identifier; generating a sounding frame to include the cluster identifier in a field (e.g., a transmit identity field) of the sounding frame; and transmitting the sounding frame.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: generating a probe announcement message to include the cluster identifier; and transmitting the sounding announcement message. In another aspect, the method performed by the non-transitory computer readable medium further comprises: negotiating with a second access point to form a cluster comprising the first access point and the second access point; generating a sounding frame to include a basic service set identifier of an access point included in the cluster; and transmitting the sounding frame.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: generating an association message to include a basic service set identifier of an access point included in the cluster; and transmitting the association message to the second station to associate the access point with the second station. In another aspect, the method performed by the non-transitory computer readable medium further comprises: generating a sounding announcement message to include a basic service set identifier of an access point included in the cluster; and transmitting the sounding announcement message.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: the beamforming report is decoded to determine first sounding information for a communication path between the device and a second access point. In another aspect, the method performed by the non-transitory computer readable medium further comprises: the method also includes decoding the beamforming report to determine second sounding information for a second communication path between the device and the access point, and transmitting a second message to include one or both of the first sounding information and the second sounding information. In another aspect, the method performed by the non-transitory computer readable medium further comprises: a second beamforming report is received from a second device that is not associated with the access point. In this aspect, the first beamformed report and the second beamformed report are received in a multi-user uplink transmission.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: transmitting a beamforming trigger message to the device, the trigger message requesting transmission of a beamforming report from the device. In this regard, the transmission of the beamforming trigger message is in response to the transmission of the sounding frame. Further in this aspect, the method performed by the non-transitory computer readable medium further comprises: negotiating with a second access point to determine a cluster identifier that associates the first access point with the second access point; and generating a trigger message to include the cluster identifier. Moreover, the method performed by the non-transitory computer readable medium further comprises: negotiating with a second access point to determine an association between the first access point and the second access point; and generating a trigger message to include Basic Service Set Identifiers (BSSIDs) of the first access point and the second access point based on the association.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: the user information field of the beamforming report is decoded to determine a medium access control address of the device. In this aspect, the method further comprises: generating an association identifier for the second station to include an identifier of the access point; associating with the second station based on the association identifier; and decoding a user information field in the first message to determine an association identifier of the second station.

Fig. 11 is a flow diagram of an exemplary method of sounding a wireless network. In some aspects, process 1100, discussed below with respect to fig. 11, may be performed by device 202. For example, in some aspects, instructions stored in memory 306 may configure hardware processor 204 to perform one or more of the functions discussed below.

Process 1100, discussed below with respect to fig. 11, allows for the collection of information regarding communication paths between an access point and one or more stations that may not be associated with the access point. In other words, the access point and the station may be in different basic service sets. The information about the communication path may include one or more of: channel coefficients, path loss information, RSSI indications, and possibly other information that can assist a transmitting device in determining how best to transmit a signal over a communication path to a destination device to provide enhanced quality of the signal when received by the device.

As described above, when joint MIMO communication is performed, simultaneous transmission on a single channel is performed using multiple BSSs, information of a communication path between non-associated devices may be used. Since signals from multiple BSSs interfere with each other, the information about the communication paths can enable transmitting devices within multiple BSSs to customize their transmission signals to reduce such interference in some scenarios. Information about the communication path may also be used for coordinated beamforming transmission. Such transmissions may include transmissions of a single nulled interference caused by a second signal that is also simultaneously transmitted. The blanking signal may reduce interference caused by the second signal at the device.

In some aspects, process 1100 may be used by various stations to provide sounding information regarding communication paths between the station and one or more access points associated with different stations. The various stations may receive sounding frames from the OBSS access point and report the resulting sounding information to their BSS access point or, in some aspects, to the OBSS access point that is coordinating the collection of sounding information. For example, in some aspects, one access point within a cluster may lead to collecting probe information and distributing it to other access points in the cluster if necessary. In some other aspects, each access point in the cluster may be responsible for collecting sounding information for stations within its own BSS. The probe information includes a characterization of a communication path between the BSS station and other access points (of different BSSs). The BSS access point, after collecting the information, may distribute the probe information to other access points in the cluster.

At block 1100, a sounding message is received by a station from a first access point. The probe-through message may be any message that allows the station to characterize a communication path between the station and the access point. In some aspects, the sounding message is a Null Data Packet (NDP). The first access point is not associated with the station. In other words, a first access point may define or coordinate communications for a first BSS, while the station may be associated with a second access point that manages or coordinates communications for a second BSS.

At block 1120, a beamforming report is generated by the station based on the sounding message. As discussed above, one or more of the channel coefficients, the path loss information, and the RSSI indication may be generated based on a sounding message from the first access point. At least a portion of the information may be included in a beamforming report.

At block 1130, a beamforming report is transmitted by the station to the first access point.

Some aspects of process 1100 include: a sounding announcement message is received by the station from the first access point, the sounding announcement message indicating that the station is to sound communications from the access point, e.g., via one or more fields set to one or more predetermined values. In some aspects, the communication is a probe message.

Some aspects of process 1100 include receiving, by the station, a beamforming report trigger message from a first access point. The beamforming report trigger message indicates via one or more fields, e.g., set to one or more predetermined values, that the station is to transmit a beamforming report to the first access point. In these aspects, the beamforming report is transmitted in response to a beamforming report trigger message. In some aspects, the beamforming report is transmitted to the first access point as part of a joint uplink multi-user communication to the first access point.

In some aspects, a trigger message is received, the trigger message is decoded to determine whether the station is identified by the trigger, and the beamforming report is transmitted based on whether the station is identified. In some aspects, the trigger may be decoded to determine values of a cluster identifier, a medium access control address, and a BSSID list, and determining whether the station is identified is based on the decoded values. For example, if the trigger message specifies the MAC address of the station as one of the devices that should respond to the trigger message, a beamforming report may be transmitted in response to the trigger.

Another disclosed aspect is a non-transitory computer-readable medium comprising instructions that, when executed, cause an electronic hardware processor to perform a method of probing a wireless network, the method comprising: receiving, by a station, a sounding message from a first access point, wherein the station is associated with a second access point different from the first access point; generating, by the station, a beamforming report based on the sounding message; the beamforming report is transmitted by the station over a wireless network. In another aspect, a method performed by the non-transitory computer readable medium comprises: receiving a trigger frame from a second access point; determining that the trigger frame includes an indication of the second access point and also includes an identifier of the first wireless device; and transmitting the first beamforming information to the second access point based on the indication and the identifier.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: receiving, by the station, a sounding announcement message from the first access point, the sounding announcement message indicating that the station is to sound a communication from the access point, wherein the sounding message is the communication. In another aspect, the method performed by the non-transitory computer readable medium further comprises: receiving, by the station, a second sounding message from a third access point that is not associated with the station; and generating, by the station, a beamforming report based on the second sounding message.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: the first sounding message and the second sounding message are received in a joint MIMO communication from the first access point and a third access point. In another aspect, the method performed by the non-transitory computer readable medium further comprises: the first and second sounding messages are received on interleaved tones or as a Q matrix encoding the two sounding messages.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: the first sounding message is received a short interframe space (SIFS) time after the second sounding message. In another aspect, the method performed by the non-transitory computer readable medium further comprises: receiving, by the station, a beamforming report trigger message from the first access point, the beamforming report trigger message indicating that the station is to transmit a beamforming report to the first access point, wherein the transmission of the beamforming report to the first access point by the station is in response to the beamforming report trigger message identifying the first access point.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: receiving, by the station, a beamforming report trigger message from a second access point associated with the station, the beamforming report trigger message indicating that the station is to transmit a beamforming report to the second access point, wherein the transmission of the beamforming report to the second access point is in response to the beamforming report trigger message identifying the second access point.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: the beamforming report is transmitted as part of a joint uplink multi-user communication. In another aspect, the method performed by the non-transitory computer readable medium further comprises: decoding a beamforming report trigger message to determine whether the station is identified by the beamforming report trigger message; and transmitting a beamforming report based on whether the station is identified. In another aspect, the method performed by the non-transitory computer readable medium further comprises: decoding one or more of a cluster identifier, a media access control address, and a list of basic service set identifiers from a beamforming report trigger message; and determining whether the station is identified based on the decoding.

Fig. 12 is a flow diagram of an example method of sounding a wireless network. In some aspects, process 1200 discussed below with respect to fig. 12 may be performed by device 202. For example, in some aspects, instructions stored in the memory 206 may configure the hardware processor 204 to perform one or more of the functions discussed below with reference to fig. 12.

Process 1200, discussed below with respect to fig. 12, allows for the collection of information regarding communication paths between an access point and one or more stations that may not be associated with the access point. In other words, the access point and the station may be in different basic service sets. The information about the communication path may include one or more of: channel coefficients, path loss information, RSSI indications, and possibly other information that can assist a transmitting device in determining how best to transmit a signal over a communication path to a destination device to provide enhanced quality of the signal when received by the device.

As described above, when joint MIMO communication is performed, simultaneous transmission on a single channel is performed using multiple BSSs, information of a communication path between non-associated devices may be used. Since signals from multiple BSSs interfere with each other, the information about the communication paths can enable transmitting devices within multiple BSSs to customize their transmission signals to reduce such interference in some scenarios. Information about the communication path may also be used for coordinated beamforming transmission. Such transmissions may include transmissions of an interference blanking signal, the interference being caused by a second signal that is also simultaneously transmitted. The blanking signal may reduce interference caused by the second signal at the device.

In some aspects, process 1200 allows the first access point to collect sounding information from associated stations (stations within its BSS). The probe information includes a characterization of the communication paths between the stations and other access points. After receiving the probe information, the receiving access point may transmit the probe information to other access points, which may utilize this information to facilitate joint MIMO communication or coordinated beamforming communication, as described above, e.g., with reference to fig. 3.

At block 1210, a first message is received by a first access point from a wireless network. The first message includes a beamforming report for a first station associated with the first access point. In some aspects, the beamforming report includes data indicative of a characteristic of a communication path between the first station and the second access point on the wireless network. For example, one or more of channel coefficients, path loss information, and/or RSSI indications may be included in the beamforming report.

At block 1220, the beamforming report is decoded to obtain sounding information for the first station related to the second access point, as discussed above.

At block 1230, the sounding information is transmitted to the second access point. In some aspects, the probe message may be transmitted over the wireless network. Alternatively, the first access point may transmit the sounding information over another network, such as a backhaul network (e.g., connecting the first and second access points), for example, via a wired networking link. The second access point may utilize the sounding information when performing coordinated beamforming or joint MIMO transmission, as described with reference to fig. 3. For example, the second access point may adjust transmission of signals to the first station based on the sounding information. The signal may null interference at the first station caused by another transmission performed by the second access point, e.g., another transmission by the second access point to a station associated with the second access point (i.e., a station within the BSS of the second access point).

In some aspects, a beamforming report from the first station is decoded to determine sounding information for the third access point. The information may be communicated by the first access point to the third access point. The third access point may utilize this information in transmitting the coordinated beamforming transmission or the joint MIMO transmission including the first station, as described above.

Some aspects of process 1200 include receiving, by the first access point, a second message comprising a second beamforming report. The second message may be from a second station (e.g., a second station connected to the first access point). The second message may be decoded by the first access point to determine sounding information for the second station. The sounding information for the second station may include a characterization of a communication channel between the second station and the second access point. The probe information may also be communicated to the second access point. In some aspects, the first message and the second message are received as part of a multi-user communication.

In some aspects, process 1200 includes transmitting, by a first access point, a sounding frame. In some aspects, the sounding frame may be a null data frame or a packet (NDP). In some aspects, the transmission of the sounding frame may be in response to receiving a sounding announcement message indicating that the first access point is to transmit the sounding frame, e.g., via a field having a predetermined value.

In some aspects, process 1200 includes transmitting, by the first access point, a sounding announcement message. The sounding announcement message may be configured to indicate, e.g., via a field having a predetermined value, that the addressed recipient device or recipient device otherwise indicated by the sounding announcement message should transmit a sounding message, such as an NDP frame. For example, the sounding announcement message may include a cluster identifier or list of devices that are to transmit sounding frames upon receiving the sounding announcement message. The transmission of the sounding frame may be in response to a sounding announcement message.

Some aspects of process 1200 include transmitting, by a first access point, a beamforming report trigger frame to a first station. The beamforming report trigger frame is configured to indicate, e.g., via one or more fields having one or more corresponding values, that devices addressed by the trigger frame (e.g., via a cluster id or list of BSSs, or a MAC address or AID list) should transmit their respective beamforming reports to the first access point. In some aspects, the trigger frame indicates that stations outside of the BSS of the first access point are to transmit beamforming reports. This may be indicated via the cluster id or BSSID list, as discussed above.

In some aspects, a first access point coordinates transmission of a sounding frame with one or more other access points (such as a second access point) such that the sounding frame is transmitted simultaneously with transmission of the sounding frames by the other access points. In some aspects, the coordinating includes assigning sets of interleaved tones to the first access point and the other access points such that multiple sounding frames are transmitted simultaneously using the interleaved tones. In other aspects, the Q matrix is used to perform simultaneous transmission of sounding frames by multiple access points.

Another disclosed aspect is a method of sounding a wireless network, comprising: receiving, by a first access point, a first message comprising a beamforming report for a first station (e.g., connected with the first access point); decoding the beamforming report to determine first station sounding information for the second access point; and transmitting the probe information to the second access point. The method further comprises the following steps: decoding the beamforming report to determine first station second sounding information for a third access point; and transmitting the first station second probe information to the third access point.

In another aspect, the method further comprises: receiving a second message comprising a second beamforming report for a second station (e.g., connected with the first access point); decoding the second beamforming report to determine second station sounding information for the second access point; and transmitting the second station probe information to the second access point. In another aspect, the method further comprises: the first message and the second message are received as a multi-user uplink transmission.

In another aspect, the method further comprises: a sounding frame is transmitted. In another aspect, the method further comprises: a sounding announcement message is received from the second access point, wherein the transmission of the sounding frame is in response to the sounding announcement message. In another aspect, the method further comprises: the sounding announcement message is a Null Data Packet (NDP). In another aspect, the method further comprises: transmitting a sounding announcement message to the second access point, wherein the transmission of the sounding frame is in response to the sounding announcement message.

In another aspect, the method further comprises: a trigger frame is transmitted by the first access point to the first station, the trigger frame indicating that the first station is to transmit sounding information. In another aspect, the method further comprises: the trigger frame further indicates that the OBSS station is to transmit a beamforming report. In another aspect, the sounding frame is transmitted simultaneously with a second sounding frame from a second access point. In another aspect, the method further comprises: the sounding frame and a second sounding frame from a second access point are transmitted with interleaved tones or a Q matrix used to encode the two sounding frames.

Another disclosed aspect is an apparatus for sounding a wireless network, comprising: an electronic hardware processor, an electronic hardware memory operatively connected to the electronic hardware processor and storing instructions that, when executed by the electronic hardware processor, cause the electronic hardware processor to: receiving, by a first access point, a first message comprising a beamforming report for a first station (e.g., connected with the first access point); decoding the beamforming report to determine first station sounding information for the second access point; and transmitting the probe information to the second access point. In an aspect, the apparatus is further configured to: decoding the beamforming report to determine first station second sounding information for a third access point; and transmitting the first station second probe information to the third access point.

In an aspect, the apparatus is further configured to: receiving a second message comprising a second beamforming report for a second station (e.g., connected with the first access point); decoding the second beamforming report to determine second station sounding information for the second access point; and transmitting the second station probe information to the second access point. In an aspect, the apparatus is further configured to: the first message and the second message are received as a multi-user uplink transmission. In an aspect, the apparatus is further configured to transmit a sounding frame.

In an aspect, the apparatus is further configured to: a sounding announcement message is received from the second access point, wherein the transmission of the sounding frame is in response to the sounding announcement message. In an aspect, the sounding announcement message is a Null Data Packet (NDP). In an aspect, the apparatus is further configured to: transmitting a sounding announcement message to the second access point, wherein the transmission of the sounding frame is in response to the sounding announcement message. In an aspect, the apparatus is further configured to: a trigger frame is transmitted by the first access point to the first station, the trigger frame indicating that the first station is to transmit sounding information. In an aspect, the trigger frame further indicates that the OBSS station is to transmit a beamforming report. In an aspect, the sounding frame is transmitted simultaneously with a second sounding frame from a second access point. In an aspect, the apparatus is further configured to: the sounding frame and a second sounding frame from a second access point are transmitted with interleaved tones or a Q matrix used to encode the two sounding frames.

Another disclosed aspect is a non-transitory computer-readable storage medium comprising instructions that, when executed, cause an electronic hardware processor to perform a method of probing a wireless network, comprising: receiving, by a first access point, a first message comprising a beamforming report for a first station (e.g., connected with the first access point); decoding the beamforming report to determine first station sounding information for the second access point; and transmitting the probe information to the second access point. In another aspect, the method performed by the non-transitory computer readable medium further comprises: decoding the beamforming report to determine first station second sounding information for a third access point; and transmitting the first station second probe information to the third access point.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: receiving a second message comprising a second beamforming report for a second station (e.g., connected with the first access point); decoding the second beamforming report to determine second station sounding information for the second access point; and transmitting the second station probe information to the second access point. In another aspect, the method performed by the non-transitory computer readable medium further comprises: the first message and the second message are received as a multi-user uplink transmission. In another aspect, the method performed by the non-transitory computer readable medium further comprises: a sounding frame is transmitted.

In another aspect, the method performed by the non-transitory computer readable medium further comprises: a sounding announcement message is received from the second access point, wherein the transmission of the sounding frame is in response to the sounding announcement message. In another aspect, the sounding announcement message is a Null Data Packet (NDP). In another aspect, the method performed by the non-transitory computer readable medium further comprises: transmitting a sounding announcement message to the second access point, wherein the transmission of the sounding frame is in response to the sounding announcement message. In another aspect, the method performed by the non-transitory computer readable medium further comprises: a trigger frame is transmitted by the first access point to the first station, the trigger frame indicating that the first station is to transmit sounding information. In an aspect, the trigger frame further indicates that the OBSS station is to transmit a beamforming report. In an aspect, the sounding frame is transmitted simultaneously with a second sounding frame from a second access point. In another aspect, the method performed by the non-transitory computer readable medium further comprises: the sounding frame and a second sounding frame from a second access point are transmitted with interleaved tones or a Q matrix used to encode the two sounding frames.

Fig. 13 is a flow diagram of an exemplary method of sounding a wireless network. In some aspects, process 1300 discussed below with respect to fig. 13 may be performed by device 202. For example, in some aspects, instructions stored in the memory 206 may configure the hardware processor 204 to perform one or more of the functions discussed below with reference to fig. 13.

Process 1300, discussed below with respect to fig. 13, allows for the collection of information regarding communication paths between an access point and one or more stations that may not be connected to (and/or "in communication with") the access point. In other words, the access point and the station may be in different basic service sets. The information about the communication path may include one or more of: channel coefficients, path loss information, RSSI indications, and possibly other information that can assist a transmitting device in determining how best to transmit a signal over a communication path to a destination device to provide enhanced quality of the signal when received by the device.

As described above, when joint MIMO communication is performed, simultaneous transmission on a single channel is performed using multiple BSSs, information of a communication path between non-associated devices may be used. Since signals from multiple BSSs interfere with each other, the information about the communication paths can enable transmitting devices within multiple BSSs to customize their transmission signals to reduce such interference in some scenarios. Information about the communication path may also be used for coordinated beamforming transmission. Such transmissions may include transmissions of a single nulled interference caused by a second signal that is also simultaneously transmitted. The blanking signal may reduce interference caused by the second signal at the device.

In some aspects, process 1300 allows an access point to calculate sounding statistics for one or more stations within its BSS. In some aspects, the access point calculates sounding statistics only for stations within its BSS that can be characterized as non-reuse STAs. This information may then be communicated to other access points, which may utilize the information in at least some aspects to cancel their interference to those non-reused STAs.

At block 1310, a sounding frame is received by a first access point. The sounding frame is received from a first station not associated with the first access point. In other words, the first station is an OBSS station with respect to the first access point.

At block 1320, a beamforming report for the station is generated by the first access point based on the sounding frame. The beamforming report may include sounding information related to a channel path between the OBSS station and the first access point. For example, upon receiving the sounding frame, the access point may determine one or more of channel coefficients, path loss, and/or RSSI information related to a channel used to transmit/receive the sounding frame. This information may be included in the beamforming report.

At block 1330, the beamforming report is transmitted to the second access point.

In some aspects of process 1300, the first access point and the second access point coordinate to determine the sounding time. In some aspects, the coordination includes exchanging messages between at least two access points, thereby causing the two access points to jointly define a sounding time. The first access point may then be ready to receive a sounding frame from the OBSS station based on the sounding time. For example, the first access point may configure the receive filter such that messages received from the OBSS station are not dropped by the receiver hardware or lower software layers within the device, and are instead allowed to be processed by additional hardware/software functions of the device such that probe messages may be determined.

Some aspects of process 1300 include transmitting a trigger frame to one or more stations (e.g., connected with a first access point) based on a sounding time. The trigger frame may indicate, e.g., via one or more fields having one or more predetermined values, that the station addressed by the trigger frame is to transmit a sounding frame. The station may be addressed by the trigger by any of the means discussed above, for example, by including the first access point BSSID in the trigger frame. One or more APs (other than the first access point) may calculate the sounding statistics based on the sounding frame brought by the trigger frame. The APs may use the statistics in performing coordinated beamforming transmissions or joint MIMO transmissions that include one or more stations (e.g., connected with the first access point).

Another disclosed aspect is a method of sounding a wireless network, comprising: receiving, by an access point having a basic service set, a sounding frame from a station outside the basic service set; generating a beamforming report for the station based on the sounding frame; the beamforming report is transmitted to the second access point. In one aspect, the method further comprises: negotiating with a second access point to determine a sounding time; and receiving a sounding frame in response to the sounding time. In one aspect, the method further comprises: a trigger is transmitted to a station (e.g., connected to the access point) based on the sounding time, the trigger message indicating that the station is to transmit a sounding frame.

Another disclosed aspect is an apparatus for sounding a wireless network, comprising: an electronic hardware processor, an electronic hardware memory operatively connected to the electronic hardware processor and storing instructions that, when executed by the electronic hardware processor, cause the electronic hardware processor to: receiving, by an access point having a basic service set, a sounding frame from a station outside the basic service set; generating a beamforming report for the station based on the sounding frame; the beamforming report is transmitted to the second access point. In an aspect, the electronic hardware memory stores further instructions that configure the electronic hardware processor to: negotiating with a second access point to determine a sounding time; and receiving a sounding frame in response to the sounding time. In an aspect, the electronic hardware memory stores further instructions that configure the electronic hardware processor to: a trigger is transmitted to a station (e.g., connected to the access point) based on the sounding time, the trigger message indicating that the station is to transmit a sounding frame.

Another disclosed aspect is a non-transitory computer-readable medium comprising instructions that, when executed, cause an electronic hardware processor to perform a method of probing a wireless network, the method comprising: receiving, by an access point having a basic service set, a sounding frame from a station outside the basic service set; generating a beamforming report for the station based on the sounding frame; the beamforming report is transmitted to the second access point. In one aspect, the method further comprises: negotiating with a second access point to determine a sounding time; and receiving a sounding frame in response to the sounding time. In one aspect, the method further comprises: a trigger is transmitted to a station (e.g., connected to the access point) based on the sounding time, the trigger message indicating that the station is to transmit a sounding frame.

As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" can include calculating, computing, processing, deriving, studying, looking up (e.g., looking up in a table, database, or other data structure), ascertaining, and the like. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Also, "determining" may include resolving, selecting, choosing, establishing, and the like. In addition, "channel width" as used herein may encompass in some aspects or may also be referred to as bandwidth.

As used herein, a phrase referring to "at least one of a list of items" refers to any combination of these items, including a single member. By way of example, "at least one of a, b, or c" is intended to encompass: a. b, c, a-b, a-c, b-c, and a-b-c.

The various operations of the methods described above may be performed by any suitable means capable of performing the operations, such as various hardware and/or software components, circuits, and/or modules. In general, any of the operations illustrated in the figures may be performed by corresponding functional means capable of performing the operations.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a field programmable gate array signal (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

In one or more aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media, including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk (disk) and disc (disc), as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks (disks) usually reproduce data magnetically, while discs (discs) reproduce data optically with lasers. Thus, in some aspects, computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media). Additionally, in some aspects, the computer readable medium may comprise a transitory computer readable medium (e.g., a signal). Combinations of the above should also be included within the scope of computer-readable media.

The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another without departing from the scope of the present disclosure. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the present disclosure.

The functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions on a computer-readable medium. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk (disk) and disc (disc), as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk, anddisks, where a disk (disk) usually reproduces data magnetically, and a disk (disc) reproduces data optically with a laser.

Accordingly, certain aspects may comprise a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and/or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein. For certain aspects, the computer program product may include packaging materials.

The software or instructions may also be transmitted over a transmission medium. For example, if the software is transmitted from a web site, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of transmission medium.

Further, it is to be appreciated that modules and/or other appropriate means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station where applicable. For example, such a device can be coupled to a server to facilitate the transfer of an apparatus for performing the methods described herein. In some aspects, the means for receiving may comprise one or more of: receiver 212, transceiver 214, DSP 220, processor 204, memory 206, signal detector 218, cellular modem 234, WLAN modem 238, or equivalents thereof. In some aspects, the means for transmitting may comprise one or more of: transmitter 210, transceiver 214, DSP 220, processor 204, memory 206, cellular modem 234, WLAN model 238, or an equivalent thereof. In some aspects, the means for determining, the means for utilizing, the means for excluding, the means for signaling, the means for initiating, the means for measuring, the means for separately determining, the means for adjusting, the means for deriving, the means for combining, or the means for evaluating may comprise one or more of: DSP 220, processor 204, memory 206, user interface 222, cellular modem 234, WLAN modem 238, or equivalents thereof.

Alternatively, the various methods described herein can be provided via a storage device (e.g., RAM, ROM, a physical storage medium such as a Compact Disc (CD) or floppy disk, etc.), such that upon coupling or providing the storage device to a user terminal and/or base station, the apparatus can obtain the various methods. Further, any other suitable technique suitable for providing the methods and techniques described herein to a device may be utilized.

It is to be understood that the present disclosure is not limited to the precise configuration and components illustrated above. Various changes, substitutions and alterations in the arrangement, operation and details of the method and apparatus described above may be made without departing from the scope of the disclosure.

While the foregoing is directed to aspects of the present disclosure, other and further aspects of the disclosure may be devised without departing from the basic scope thereof.

(1) A method of sounding a wireless network, comprising:

receiving, by a first access point having a Basic Service Set (BSS), a first message comprising first beamforming information from a first wireless device that is not associated with the first access point;

generating, at the first access point, a second message based on the first beamforming information; and transmitting the second message from the first access point to the first wireless device.

(2) The method of (1), further comprising:

forming a cluster comprising the first access point and a second access point; and assigning a cluster identifier to the cluster.

(3) The method of (2), further comprising:

communicating, by the first access point, with a second wireless device based at least in part on the cluster identifier;

generating, at the first access point, a sounding announcement message including the cluster identifier; and transmitting the sounding announcement message from the first access point to at least the second wireless device.

(4) The method of (2), further comprising:

generating, at the first access point, a sounding frame to include one or both of:

the cluster identifier in a field of the sounding frame, and a set of basic service set identifiers of access points included in the cluster; and transmitting the sounding frame from the first access point to at least the second wireless device.

(5) The method of (4), wherein the sounding frame is generated to include the set of basic service set identifiers, and further comprising:

generating, at the first access point, a third message to include a set of basic service set identifiers; and transmitting the third message to a third wireless device.

(6) The method of (4), further comprising generating the sounding announcement message to include a set of basic service set identifiers.

(7) The method of (1), further comprising:

decoding the first beamforming information to determine first sounding information for a first communication path between the first wireless device and the first access point; and

decoding the first beamforming information to further determine second sounding information for a second communication path between the first wireless device and a second access point,

wherein the first access point transmits the second message to include one or both of the first sounding information and the second sounding information.

(8) The method of (1), further comprising receiving a multi-user uplink transmission comprising the first beamforming information and second beamforming information, wherein the second beamforming information is for a second wireless device that is outside of the basic service set.

(9) The method of (1), further comprising:

transmitting a sounding frame from the first access point to the first wireless device; and

transmitting, from the first access point to the first wireless device, a beamforming frame in response to transmitting the sounding frame, the beamforming frame including a request for transmission of first beamforming information from the first wireless device.

(10) The method of (9), further comprising:

forming a cluster comprising the first access point and a second access point;

assigning a cluster identifier to the cluster; and generating the beamforming frame to include the cluster identifier.

(11) The method of (9), further comprising:

communicate with a second access point to determine communication between the first access point and the second access point; and

generating the beamforming frame to include a set of basic service set identifiers of the first access point and the second access point based on the communication.

(12) The method of (1), further comprising decoding a user information field further included in the first message to determine a medium access control address of the first wireless device.

(13) The method of (12), further comprising: decoding the second user information field to determine a second media access control address of the second wireless device;

generating a third message to include an identifier of the first access point; and communicating with the second wireless device based on the identifier.

(14) An apparatus for probing a wireless network, the apparatus comprising: an electronic hardware processor;

an electronic hardware memory storing instructions that, when executed, cause the electronic hardware processor to:

receiving, by the apparatus, a first message comprising first beamforming information from a first wireless device not associated with the apparatus;

generating, at the apparatus, a second message based on the first beamforming information; and transmitting the second message from the apparatus to the first wireless device.

(15) The apparatus of (14), wherein the electronic memory stores additional instructions that configure the electronic hardware processor to:

forming a cluster comprising the apparatus and a second access point; and assigning a cluster identifier to the cluster.

(16) A method of sounding a wireless network, comprising:

receiving, by a first wireless device, a first sounding message from a first access point;

generating, by the first wireless device, a first message comprising first beamforming information based on the first sounding message; and

transmitting, by the first wireless device, the first message over the wireless network.

(17) The method of (16), further comprising:

decoding, by the first wireless device, one or more parameters from the first sounding message, the one or more parameters including a cluster identifier, a list of basic service set identifiers, and a transmitter address; and

determining, by the first wireless device, whether to generate the first message based on comparing the one or more parameters to information received during communication with the second access point.

(18) The method of (16), further comprising receiving, at the first wireless device, a sounding announcement message from the first access point prior to receiving the first sounding message, the sounding announcement message including an indication that the first wireless device is to sounding the first sounding message.

(19) The method of (16), further comprising:

receiving, by the first wireless device, a second sounding message from a third access point that is not associated with the first wireless device; and

generating, by the first wireless device, the first message further based on the second sounding message.

(20) The method of (19), wherein the first wireless device receives the first and second sounding messages via:

distributed multiple-input multiple-output (MIMO) communications from the first access point and the third access point, and interleaved sets of tones or Q-matrix coding.

(21) The method of (19), wherein the first wireless device receives the first sounding message within a short interframe space (SIFS) time after receiving the second sounding message.

(22) The method of (16), further comprising:

receiving, by the first wireless device, a beamformed frame from the first access point;

determining that the beamforming frame includes an indication of the first access point; and transmitting the first message from the first wireless device to the first access point based on the indication.

(23) The method of (16), further comprising:

receiving, by the first wireless device, a beamformed frame from the second access point;

determining that the beamforming frame includes an indication of the second access point; and

transmitting, from the first wireless device to the second access point, the first beamforming information based on the indication.

(24) The method of (23), further comprising:

decoding one or more of a cluster identifier, a media access control address, and a list of basic service set identifiers from the beamformed frame;

determining, based on the decoding, that the beamforming frame includes an identifier of the first wireless device; and

transmitting the first beamforming information from the first wireless device to the second access point further based on the identifier.

(25) The method of (16), further comprising transmitting the first message as part of a joint uplink multi-user communication.

(26) An apparatus for sounding a wireless network, comprising:

an electronic hardware processor;

an electronic hardware memory storing instructions that, when executed, cause the electronic hardware processor to:

receiving, by the apparatus, a first sounding message from a first access point;

generating, by the apparatus, a first message comprising first beamforming information based on the first sounding message; and

transmitting, by the apparatus, the first message over the wireless network.

(27) The apparatus of (26), wherein the electronic hardware memory further stores instructions that configure the electronic hardware processor to:

decoding, by the apparatus, one or more parameters from the first sounding message, the one or more parameters including a cluster identifier, a list of basic service set identifiers, and a transmitter address; and

determining, by the apparatus, whether to generate the first message based on comparing the one or more parameters to information received during communication with the second access point.

(28) The apparatus of (26), wherein the electronic hardware memory further stores instructions that configure the electronic hardware processor to: prior to receiving the first sounding message, receiving, at the apparatus, a sounding announcement message from the first access point, the sounding announcement message including an indication that the apparatus is to sound the first sounding message.

(29) The apparatus of (26), wherein the electronic hardware memory further stores instructions that configure the electronic hardware processor to:

receiving, by the apparatus, a second sounding message from a third access point that is not associated with the apparatus; and

generating, by the apparatus, the first message further based on the second sounding message.

(30) The apparatus of (29), wherein the electronic hardware memory further stores instructions that configure the electronic hardware processor to: receiving the first and second sounding messages via:

distributed multiple-input multiple-output communication from the first access point and the third access point, an

Interleaved tone sets or Q matrix coding.

Claims (28)

1. A method of sounding a wireless network associated with a plurality of basic service sets, BSSs, the method performed by a first access point corresponding to a first BSS and comprising:

receiving a first message comprising first beamforming information from a first wireless device not associated with the first access point, the first beamforming information indicating channel conditions between the first wireless device and the first access point and indicating channel conditions between the first wireless device and a second access point corresponding to a second BSS;

determining first sounding information for a first communication path between the first wireless device and the first access point based on the first beamforming information;

determining second sounding information for a second communication path between the first wireless device and the second access point based on the first beamforming information; and

transmitting a second message to the first wireless device based on the first beamforming information, wherein the second message comprises one or both of the first sounding information and the second sounding information.

2. The method of claim 1, further comprising:

forming a cluster comprising the first access point and the second access point; and

a cluster identifier is assigned to the cluster.

3. The method of claim 2, further comprising:

communicate with a second wireless device associated with the second access point based at least in part on the cluster identifier; and

transmitting a sounding announcement message including the cluster identifier to at least the second wireless device.

4. The method of claim 3, further comprising:

transmitting a sounding frame comprising at least one of:

the cluster identifier, and a set of BSS identifiers of access points included in the cluster.

5. The method of claim 4, wherein the method further comprises:

transmitting a third message comprising the set of BSS identifiers to a third wireless device.

6. The method of claim 4, wherein the sounding announcement message includes the set of BSS identifiers.

7. The method of claim 1, further comprising:

receiving a multi-user uplink transmission including the first beamforming information provided by the first wireless device and including second beamforming information provided by a second wireless device external to the first BSS.

8. The method of claim 1, further comprising:

transmitting a sounding frame; and

transmitting a trigger frame comprising a request for transmission of the first beamforming information from the first wireless device.

9. The method of claim 8, further comprising:

forming a cluster comprising the first access point and the second access point; and

assigning a cluster identifier to the cluster, wherein the trigger frame includes the cluster identifier.

10. The method of claim 8, further comprising:

communicate with the second access point to determine a BSS identifier of the second access point, wherein the trigger frame includes a set of BSS identifiers of the first access point and the second access point.

11. The method of claim 1, further comprising:

decoding a user information field included in the first message to determine a media access control, MAC, address of the first wireless device.

12. The method of claim 11, further comprising:

decoding a second user information field included in the first message to determine a second MAC address of a second wireless device;

generating a third message to include an identifier of the first access point; and

communicating with the second wireless device based on the identifier.

13. An apparatus for sounding a wireless network associated with a plurality of basic service sets, BSSs, the apparatus corresponding to a first BSS and comprising:

one or more processors;

memory storing a computer program that, when executed by the one or more processors, causes the apparatus to:

receiving a first message comprising first beamforming information from a first wireless device not associated with the apparatus, the first beamforming information indicating channel conditions between the first wireless device and the apparatus and indicating channel conditions between the first wireless device and a second access point corresponding to a second BSS;

determining first sounding information for a first communication path between the first wireless device and the apparatus based on the first beamforming information;

determining second sounding information for a second communication path between the first wireless device and the second access point based on the first beamforming information; and

transmitting a second message to the first wireless device based on the first beamforming information, wherein the second message comprises one or both of the first sounding information and the second sounding information.

14. The apparatus of claim 13, wherein execution of the computer program further causes the apparatus to:

forming a cluster comprising the apparatus and the second access point; and

a cluster identifier is assigned to the cluster.

15. A method of sounding a wireless network by a first wireless device, comprising:

receiving a first sounding message from a first access point not associated with the first wireless device;

determining first beamforming information based on the first sounding message, the first beamforming information indicating channel conditions between the first wireless device and the first access point;

transmitting a first message including the first beamforming information to the first access point;

receiving a trigger frame from a second access point associated with the first wireless device;

determining that the trigger frame includes an indication of the second access point and also includes an identifier of the first wireless device; and

transmitting the first beamforming information to the second access point based on the indication and the identifier.

16. The method of claim 15, further comprising:

decoding one or more parameters from the first sounding message, the one or more parameters including a cluster identifier, a list of basic service set, BSS, identifiers, and a transmitter address; and

determining whether to generate the first message based on comparing the one or more parameters to information received during communication with the second access point.

17. The method of claim 15, further comprising receiving a sounding announcement message from the first access point, the sounding announcement message including an indication that the first wireless device is to listen for the first sounding message.

18. The method of claim 15, further comprising:

receiving a second sounding message from a third access point not associated with the first wireless device; and

generating the first message further based on the second sounding message.

19. The method of claim 18, wherein the first wireless device receives the first sounding message and the second sounding message via:

distributed multiple-input multiple-output, MIMO, communication from the first access point and the third access point, an

Receiving the first and second sounding messages on interleaved tones or as a Q matrix encoding the first and second sounding messages.

20. The method of claim 18, wherein the first wireless device receives the first sounding message a short interframe space (SIFS) time after receiving the second sounding message.

21. The method of claim 15, further comprising:

receiving a trigger frame from the first access point requesting the first beamforming information;

determining that the trigger frame includes an indication of the first access point; and

transmitting the first message to the first access point based on the indication included in the trigger frame.

22. The method of claim 15, wherein the identifier comprises one or more of: a cluster identifier, a Media Access Control (MAC) address, and a list of basic service set identifiers from the trigger frame.

23. The method of claim 15, further comprising:

transmitting the first message as part of a joint uplink multi-user communication.

24. An apparatus for sounding a wireless network, comprising:

one or more processors;

memory storing a computer program that, when executed by the one or more processors, causes the apparatus to:

receiving a first probe message from a first access point not associated with the apparatus;

determining first beamforming information based on the first sounding message, the first beamforming information indicating channel conditions between the apparatus and the first access point;

transmitting a first message including the first beamforming information to the first access point;

receiving a trigger frame from a second access point associated with the apparatus;

determining that the trigger frame includes an indication of the second access point and also includes an identifier of the apparatus; and

transmitting the first beamforming information to the second access point based on the indication and the identifier.

25. The apparatus of claim 24, wherein execution of the computer program further causes the apparatus to:

decoding one or more parameters from the first sounding message, the one or more parameters including a cluster identifier, a list of basic service set identifiers, and a transmitter address; and

determining whether to generate the first message based on comparing the one or more parameters to information received during communication with a second access point.

26. The apparatus of claim 24, wherein execution of the computer program further causes the apparatus to: receiving a sounding announcement message from the first access point, the sounding announcement message including an indication that the apparatus is to listen for the first sounding message.

27. The apparatus of claim 24, wherein execution of the computer program further causes the apparatus to:

receiving a second sounding message from a third access point that is not associated with the apparatus; and

generating the first message further based on the second sounding message.

28. The apparatus of claim 27, wherein execution of the computer program causes the apparatus to: receiving the first sounding message and the second sounding message via:

distributed multiple-input multiple-output, MIMO, communication from the first access point and the third access point, an

Receiving the first and second sounding messages on interleaved tones or as a Q matrix encoding the first and second sounding messages.