Patent ID: 12245175

Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION

The following description is directed to certain aspects for the purposes of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. The examples in this disclosure are based on wireless local area network (WLAN) communication according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless standards. However, the described aspects may be implemented in any device, system or network that is capable of transmitting and receiving radio frequency (RF) signals according to one or more of the IEEE 802.11 standards, the Bluetooth® standard, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), Global System for Mobile communications (GSM), GSM/General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (W-CDMA), Evolution Data Optimized (EV-DO), 1×EV-DO, EV-DO Rev A, EV-DO Rev B, High Speed Packet Access (HSPA), High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), Evolved High Speed Packet Access (HSPA+), Long Term Evolution (LTE), AMPS, or other known signals that are used to communicate within a wireless, cellular or internet of things (IoT) network, such as a system utilizing 3G, 4G, 5G, 6G, or further implementations thereof, technology.

A wireless local area network (WLAN) in a home, apartment, business, or other type of environment may include two or more WLAN devices. A WLAN may include one or more access points (APs) and one or more stations (STAs). An AP is a type of STA that performs a distribution system access function in the WLAN. For brevity, this disclosure refers to the WLAN devices which could either operate as an AP or a STA. An AP may provide wireless access to the STAs that are located in a coverage area of the AP. The STAs may include various types of WLAN devices such as mobile phones, laptops, gaming systems (including virtual and augmented reality systems (VR and AR, or collectively XR)), entertainment systems, smart appliances, wearables, and IoT devices. Some APs may be capable of establishing connectivity via more than one frequency band. For example, an AP may operate a first basic service set (BSS) on a first frequency band (such as a 2.4 GHz frequency band) and a second BSS on a second frequency band (such as a 5 GHz frequency band). For brevity, the first and second BSSs may be referred to as a first frequency band of the AP and a second frequency band of the AP, respectively.

WLANs typically provide network connectivity throughout a physical space. As a STA moves into the space, it may receive signals from a first AP such as a beacon frame and other signals. The STA may associate with the first AP to establish connectivity to the WLAN. If the STA moves outside a coverage area of the first AP, the signal strength of the signals received from the first AP may weaken. In some instances, the STA may be unaware of other APs, so it may remain associated with the first AP despite the weak signals. In response to the weak signals, the STA may scan for a different AP that may provide stronger signals. For example, as the STA moves outside the coverage area of the first AP, the STA may enter the coverage area of a second AP. As the STA enters the coverage area of the second AP, the first AP may attempt to steer the STA to associate with the second AP.

Various aspects of this disclosure relate generally to AP steering or frequency band steering based on a location of a STA. Some aspects more specifically relate to the use of the fine timing measurement (FTM) procedure to determine the relative distance or location of the STA for steering the STA from one AP to another AP. Some aspects relate to using the FTM procedure to determine the relative distance or location of the STA for steering the STA from a first frequency band of an AP to a second frequency band of that AP. In some implementations, an AP may determine the location of the STA based on timing information and may steer the STA based on the location. To obtain the round trip timing (RTT) information, the AP may exchange FTM frames with the STA. The AP may determine a distance between itself and the STA based on the RTT information. The AP also may obtain distance information from other APs, where the distance information may include a distance between another AP and the STA. Using the distance between itself and the STA and additional distance information (such as a distance between another AP and the STA), the AP may determine a location of the STA and steer the WLAN device based on its location. The AP may steer the WLAN device to a different frequency band of the AP or to different AP.

To facilitate steering, WLAN devices typically exchange signal information such as beacon measurement reports (defined in IEEE 802.11k) and received signal strength indicators (RSSI) measurements. For example, an AP may request a beacon measurement report from a STA, and the STA may provide the beacon measurement report to the AP. The beacon measurement report may include signal strength information of one or more beacon frames obtained from one or more APs of the WLAN. The exchange of the beacon measurement report and other signal information using existing techniques may not be instantaneous, and in some instances beacon reports may not be available. Thus, the steering process may be delayed or may not occur. For example, although the APs may periodically request beacon measurement reports, the STAs may not respond to the requests. For example, the STA may not receive the request from the AP due to interference in the WLAN and thus may not respond to the AP. As another example, the STA may delay responding to the request due to network congestion. Hence, the APs may postpone their steering processes until the APs receive the beacon measurement reports. In some instances, postponing the steering process causes the STA to remain connected to the first AP even when the STA has moved into the coverage area of the second AP which could have served the STA better than the first AP. In some instances, steering delays cause APs to miss opportunities for band steering and network load balancing. For example, some APs initiate steering when an RSSI measurement for a STA is less than a signal strength threshold. As the STA moves away from the AP, RSSI updates may be delayed because of communication problems related to low signal strength. Delayed RSSI updates may cause the AP to miss an opportunity to steer the STA to another AP. Delayed RSSI updates also may cause the AP to miss an opportunity for steering the STA from a first frequency band of the AP to a second frequency band of the AP. While the AP is waiting for the RSSI update, the STA may associate with a different AP. As an AP misses band steering opportunities, other APs in the WLAN may become overloaded.

Fine timing measurement (FTM) is a protocol that was introduced in IEEE 802.11-2016 (which incorporated IEEE 802.11mc). WLAN devices may exchange FTM frames and determine RTT by using time of departure (TOD) and time of arrival (TOA) timestamps captured during frame exchange. RTT information may include the TOD and TOA timestamps. Based on the RTT information, a WLAN device may measure an RTT relative to another WLAN device. The WLAN device may multiply the RTT by 0.5 and an approximate speed of light in the wireless medium to determine a distance between the WLAN devices. The WLAN device may repeat the process with other WLAN devices to determine relative distances of the other WLAN devices or to determine its location based on the relative distances to the other WLAN devices and their known locations.

In some implementations, an AP may determine the location of a STA based on RTT information and may steer the STA based on the location. In some implementations, an AP may exchange FTM frames with a STA to obtain RTT information that indicates a distance from the AP to the STA. The AP also may obtain distance information from other APs in the WLAN. Using the distance to the STA and the additional distance information, the AP may determine a location of the STA and steer the STA based on the location of the STA relative to the AP or to another AP.

In some implementations, a first AP may determine a first distance from itself to a STA based on RTT information. For example, the first AP may exchange FTM frames with the STA. The FTM frames may include RTT information indicating an RTT of communications between the AP and STA. Using the RTT, the AP may determine the first distance from the AP to the STA. In some implementations, the first AP also may determine a second distance from a second AP to the STA. For example, the first AP may obtain distance information from a second AP, where the distance information includes the second distance—the distance from the STA to the second AP. As another example, the first AP may obtain the distance information in an FTM range report received from the second AP or any suitable STA. In some implementations, the first AP may determine a location of the STA based on the first and second distances. The first AP may determine whether to steer the STA based on the location of the STA. For example, the first AP may steer the STA to the second AP based on the location of the STA, i.e., the STA may be more proximate to the second AP, or the STA may be capable of receiving signals with higher relative strength based on its location.

In some implementations, the first AP may steer the STA to a different frequency band. For example, the first AP may steer the STA from a second frequency band of the AP to a first frequency band of the AP based on the location of the STA. As the STA enters the coverage area of the first frequency band, the AP may steer the STA from the second frequency band to the first frequency band. For example, the first frequency band of the AP may have a greater coverage area compared to the coverage area of the second frequency band of the AP. Thus, the AP may steer the STA to the first frequency band when the STA moves to a further distance from the AP.

In some implementations, the first AP may access steering information that indicates whether to steer the STA based on its location. Depending on the location of the STA, the steering information may direct the first AP not to steer the STA, to steer the STA to the second AP, or to steer the STA to a different frequency band of the first AP, as described further herein. For example, the steering information may indicate a set of steering decisions for corresponding locations. In some implementations, the steering information may include other information, such as target APs to which the STA will be steered, distance information related to other APs, location information related to other APs, signal information related to other APs, or any other information suitable to provide a basis for determining whether to steer a WLAN device.

Some STAs may not support the FTM feature specified in IEEE 802.11-2016 and thus may not support obtaining or exchanging FTM frames. Hence, in some implementations, an AP may determine whether a STA is capable of exchanging FTM frames. In some implementations, during association, the AP may receive one or more elements indicating whether the STA is capable of obtaining or exchanging FTM frames. For example, during association, the AP may receive an Extended Capabilities element in which a field indicates the STA is capable of acting as an FTM responder. If the STA is capable of acting as an FTM responder, the STA is FTM-capable. In some implementations, the AP may receive a capabilities element indicating the STA can provide range reports indicating ranges between the STA and other APs, where the ranges are determined using the FTM procedure. A STA that is not FTM-capable also may be referred to as being FTM-incapable. An AP can determine locations of FTM-capable STAs based on RTT information obtained from the STAs and distance information from other APs. The AP may determine whether to steer the STA based on the location of the STA.

In some implementations, steering may be triggered by weak signal strength. For example, an AP may detect that an RSSI for a STA is less than a signal strength threshold. In response to determining that the RSSI for the STA is less than the signal strength threshold, the AP may determine whether the STA is FTM-capable and perform steering based on an FTM-derived location of the STA. Thus, the FTM and steering procedure may be triggered based on a reduction or change in the RSSI of signals received from the STA. The change in the RSSI may indicate, among other things, a change in the location of the STA relative to the AP. Thus, when the RSSI changes below the signal strength threshold, the AP may initiate the FTM to determine an updated location for the STA. If the STA has moved to a new location, the AP may determine whether to steer the STA based on the new location.

In some implementations, an AP can band steer FTM-capable STAs without information from other WLAN devices. For example, a STA may be associated with a second frequency band of the AP. However, the first frequency band of the AP may support a greater distance compared to the second frequency band of the AP. The AP may exchange FTM packets with the STA to determine a distance from the AP to the STA. Based on the distance, the AP may steer the STA from a second frequency band of the AP to a first frequency band of the AP.

Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. Traditional techniques for steering may involve APs sending information requests that go ignored by STAs. Unresponsive STAs may hinder the steering process. In some implementations, APs may use the FTM procedure to obtain information used in steering and achieve better responsiveness from the STAs. In some implementations, an AP using RTT information derived from FTM frames to determine the location of a STA may lead to faster steering decisions compared to existing steering techniques that use signal information such as beacon measurement reports and RSSI. The AP making faster steering decisions also may result in fewer missed steering opportunities. Using RTT information also may result in the AP more accurately determining the location of the STA. As location accuracy increases, the WLAN may make better and more consistent steering decisions. Faster and more accurate steering may lead to better STA performance and a better user experience.

Providing wireless access throughout an environment may be challenging for a single AP because various conditions may adversely affect wireless signals. As wireless signals travel over relatively long distances from the AP, the wireless signals may lose signal strength, which may degrade the wireless service being provided to STAs in the WLAN. In some environments, objects and materials may absorb, reflect, interfere with or otherwise adversely affect wireless signals. Adding one or more range extenders (REs) to a WLAN may increase signal strength in areas relatively far away from APs and in areas where wireless signals are adversely affected by environmental conditions. REs may be additional APs in a WLAN that may extend coverage areas by receiving and retransmitting wireless signals between WLAN devices. For example, the REs may retransmit wireless signals from a central AP (CAP) to STAs in the WLAN and vice versa. The CAP may be an AP that is connected to a gateway. REs and other APs may extend the service of the CAP and can be connected via wired or wireless links to the CAP.

The location of an RE may impact how well the RE increases the coverage area or otherwise increases signal strength in the WLAN. The RE may perform a process that assists in placing the RE at a suitable location. Traditional RE placement processes are based on the measured signal strength of signals received from an AP. Based on the signal strength, the RE may provide feedback indicating whether the RE should be moved nearer to an AP, farther from the AP, or remain at its current location. In some instances, there is not a simple relationship between signal strength and distance from the AP. For example, environmental conditions (such as objects, walls, and other obstructions) may cause a first RE near the AP to have lower signal strength than a second RE that is farther from the AP.

Various aspects of this disclosure relate generally to assisting with RE placement in an environment. Some aspects more specifically relate to using both FTM frames and signal strength to assist in placing the RE at a suitable location within the environment. The RE may use FTM frames to guide aspects of a coarse placement of the RE and signal strength to guide a fine placement of the RE. FTM may enable the RE to measure an RTT from itself to the AP based on FTM frames it sends to and receives from the AP. After measuring the RTT, the RE may determine a first distance from itself to the AP by multiplying the RTT by an approximate speed of light in the wireless medium. By using FTM, the RE uses RTT information and not signal strength to determine the first distance. By using RTT information (such as FTM), the RE may determine the first distance to the AP without considering how environmental conditions may affect the signal strength.

Using a first distance from the RE to the AP, the RE may determine whether it is located within an acceptable distance range from the AP for coarse placement of the RE. The acceptable distance range may be a distance range that extends the coverage area of the AP in the WLAN in a suitable manner, while maintaining a suitable signal strength. Hence, by using the acceptable distance range, the RE may use RTT information to find distances at which the signal strength and coverage area may be suitable during the coarse placement of the RE. The RE may provide a coarse placement indicator to indicate whether to move the RE nearer to the AP, farther from the AP, or whether the RE is within the acceptable distance range. The RE may repeat operations related to coarse placement until the RE is within the acceptable distance range of the AP.

If the RE is within the acceptable distance range, the RE may perform operations for a fine placement of the RE. In response to the RE determining it is located within an acceptable distance range of the AP, the RE may determine a signal strength associated with the AP. For example, for fine placement of the RE, the RE may determine an RSSI from signals received from the AP.

The RE may compare the signal strength to one or more signal strength thresholds. The one or more signal strength thresholds may relate to one or more signal strength ranges that indicate whether the RE should be relocated for fine placement of the RE. For example, a first signal strength threshold may identify a minimum signal strength below which the RE should be moved nearer to the AP. A second signal strength threshold may identify a maximum signal strength above which the RE should be moved farther from the AP. A range of values including the minimum signal strength and the maximum signal strength may indicate a signal strength range in which the RE should remain at its current location. Hence, comparing the signal strength to one or more signal strength thresholds may indicate whether the signal strength is too high, too low or within an acceptable range.

Based on a comparison of the signal strength to one or more signal strength thresholds, the RE may provide a fine placement indicator to assist with fine placement of the RE in the environment. As noted, the comparison may indicate whether the signal strength is too high, too low or within a suitable signal strength range. The fine placement indicator may relate to whether the signal strength is too high, too low or in a suitable signal strength range. For example, if the signal strength is too high, the fine placement indicator may be an indication to move the RE farther from the AP. If the signal strength is too low, the fine placement indicator may be an indication to move the RE nearer to the AP. If the signal strength is in a suitable signal strength range, the fine placement indicator may be an indication for the RE to remain at its current location. The fine placement indicator may include or otherwise cause presentation of any suitable audible or visible indication (such as beeps, flashing lights, or text on a screen) to move the RE in the environment.

Particular implementations of the subject matter described in this disclosure also can be implemented to realize one or more of the following potential advantages. In some implementations, an RE using RTT information derived from FTM frames to determine a distance to an AP may lead to faster RE placement decisions compared to RE placement techniques that use only signal information such as RSSI. The RE also may utilize signal information to provide more accurate placement guidance compared to traditional techniques for RE placement. The RE also may utilize channel state information to provide more accurate and robust placement guidance compared to traditional techniques for RE placement. The RE making faster, more accurate and more robust placement decisions may create a better user experience by reducing time users are waiting for guidance (such as audible or visual indicia) about where to place the RE within an environment.

FIG.1shows a system diagram of an example wireless communication network100. According to some aspects, the wireless communication network100can be an example of a wireless local area network (WLAN) such as a Wi-Fi network (and will hereinafter be referred to as WLAN100). For example, the WLAN100can be a network implementing at least one of the IEEE 802.11 family of standards (such as that defined by the IEEE 802.11-2016 specification or amendments thereof including, but not limited to, 802.11aa, 802.11ah, 802.11ad, 802.11aq, 802.11ay, 802.11ax, 802.11az, 802.11ba and 802.11be). The WLAN100may include numerous WLAN devices such as an access point (AP)102and multiple stations (STAs)104that have a wireless association with the AP102. While only one AP102is shown, the WLAN100also can include multiple APs102. The IEEE 802.11-2016 standard defines a STA as an addressable unit. An AP is an entity that contains at least one STA and provides access via a wireless medium (WM) for associated STAs to access a distribution service (such as another network, not shown). Thus, an AP includes a STA and a distribution system access function (DSAF). In the example ofFIG.1, the AP102may be connected to a gateway device (not shown) which provides connectivity to the other network140. The DSAF of the AP102may provide access between the STAs104and another network140. While AP102is described as an access point using an infrastructure mode, in some implementations, the AP102may be a traditional STA which is operating as an AP. For example, the AP102may be a STA capable of operating in a peer-to-peer mode or independent mode. In some other examples, the AP102may be a software AP (SoftAP) operating on a computer system.

Each of the STAs104also may be referred to as a mobile station (MS), a mobile device, a mobile handset, a wireless handset, an access terminal (AT), a user equipment (UE), a subscriber station (SS), or a subscriber unit, among other possibilities. The STAs104may represent various devices such as mobile phones, personal digital assistant (PDAs), other handheld devices, netbooks, notebook computers, tablet computers, laptops, display devices (for example, TVs, computer monitors, navigation systems, among others), music or other audio or stereo devices, remote control devices (“remotes”), printers, kitchen or other household appliances, key fobs (for example, for passive keyless entry and start (PKES) systems), among other possibilities.

A single AP102and an associated set of STAs104may be referred to as a basic service set (BSS), which is managed by the respective AP102.FIG.1additionally shows an example coverage area108of the AP102, which may represent a basic service area (BSA) of the WLAN100. The BSS may be identified to users by a service set identifier (SSID), as well as to other devices by a basic service set identifier (BSSID), which may be a media access control (MAC) address of the AP102. The AP102periodically broadcasts beacon frames (“beacons”) including the BSSID to enable any STAs104within wireless range of the AP102to establish a respective communication link106(hereinafter also referred to as a “Wi-Fi link”), or to maintain a communication link106, with the AP102. For example, the beacons can include an identification of a primary channel used by the respective AP102as well as a timing synchronization function for establishing or maintaining timing synchronization with the AP. The AP102may provide access to external networks (such as the network140) to various STAs104in the WLAN via respective communication links106. To establish a communication link106with an AP102, each of the STAs104is configured to perform passive or active scanning operations (“scans”) on frequency channels in one or more frequency bands (for example, the 2.4 GHz, 5 GHz, 6 GHz or 60 GHz bands). To perform passive scanning, a STA104listens for beacons, which are transmitted by respective APs102at a periodic time interval referred to as the target beacon transmission time (TBTT) (measured in time units (TUs) where one TU may be equal to 1024 microseconds (μs)). To perform active scanning, a STA104generates and sequentially transmits probe requests on each channel to be scanned and listens for probe responses from APs102. Each STA104may be configured to identify or select an AP102with which to associate based on the scanning information obtained through the passive or active scans, and to perform authentication and association operations to establish a communication link106with the selected AP102. The AP102may assign an association identifier (AID) to the STA104at the culmination of the association operations, which the AP102uses to track the STA104.

As a result of the increasing ubiquity of wireless networks, a STA104may have the opportunity to select one of many BSSs within range of the STA or to select among multiple APs102that together form an extended service set (ESS) including multiple connected BSSs. An extended network station associated with the WLAN100may be connected to a wired or wireless distribution system that may allow multiple APs102to be connected in such an ESS. As such, a STA104can be covered by more than one AP102and can associate with different APs102at different times for different transmissions. Additionally, after association with an AP102, a STA104also may be configured to periodically scan its surroundings to find a more suitable AP102with which to associate. For example, a STA104that is moving relative to its associated AP102may perform a “roaming” scan to find another AP102having more desirable network characteristics such as a greater received signal strength indicator (RSSI) or a reduced traffic load.

In some cases, STAs104may form networks without APs102or other equipment other than the STAs104themselves. One example of such a network is an ad hoc network (or wireless ad hoc network). Ad hoc networks may alternatively be referred to as mesh networks or peer-to-peer (P2P) networks. In some cases, ad hoc networks may be implemented within a larger wireless network such as the WLAN100. In such implementations, while the STAs104may be capable of communicating with each other through the AP102using communication links106, STAs104also can communicate directly with each other via direct wireless links107. Additionally, two STAs104may communicate via a direct communication link107regardless of whether both STAs104are associated with and served by the same AP102. In such an ad hoc system, one or more of the STAs104may assume the role filled by the AP102in a BSS. Such a STA104may be referred to as a group owner (GO) and may coordinate transmissions within the ad hoc network. Examples of direct wireless links107include Wi-Fi Direct connections, connections established by using a Wi-Fi Tunneled Direct Link Setup (TDLS) link, and other P2P group connections.

The APs102and STAs104may function and communicate (via the respective communication links106) according to the IEEE 802.11 family of standards (such as that defined by the IEEE 802.11-2016 specification or amendments thereof including, but not limited to, 802.11aa, 802.11ah, 802.11aq, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba and 802.11be). These standards define the WLAN radio and baseband protocols for the PHY and medium access control (MAC) layers. The APs102and STAs104transmit and receive wireless communications (hereinafter also referred to as “Wi-Fi communications”) to and from one another in the form of physical layer convergence protocol (PLCP) protocol data units (PPDUs).

Each of the frequency bands may include multiple sub-bands or frequency channels. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac, 802.11ax and 802.11be standard amendments may be transmitted over the 2.4 and 5 GHz bands, each of which is divided into multiple 20 MHz channels. As such, these PPDUs are transmitted over a physical channel having a minimum bandwidth of 20 MHz, but larger channels can be formed through channel bonding. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac, 802.11ax, and 802.11be standard amendments may be transmitted over physical channels having bandwidths of 40 MHz, 80 MHz, 80+80 MHz, 160 MHz, 160+160 MHz or 320 MHz by bonding together two or more 20 MHz channels, which can be contiguously allocated or non-contiguously allocated. For example, IEEE 802.11n describes the use of up to 2 channels (for a combined 40 MHz bandwidth) and defined a High Throughput (HT) transmission format. IEEE 802.11ac describes the use of up to 8 channels (for a maximum combined 160 MHz bandwidth) and defined a Very High Throughput (VHT) transmission format. IEEE 802.11ax also supports up to a combined 160 MHz bandwidth (which may be a combination of up to 8 channels of 20 MHz width each). IEEE 802.11be may support up to a combined 320 MHz bandwidth (which may be a combination of up to 16 channels of 20 MHz width each).

The APs102and STAs104in the WLAN100may transmit PPDUs over an unlicensed spectrum, which may be a portion of spectrum that includes frequency bands traditionally used by Wi-Fi technology, such as the 2.4 GHz band, the 5 GHz band, the 60 GHz band, and the 900 MHz band. Some implementations of the APs102and STAs104described herein also may communicate in other frequency bands, such as the 6 GHz band, which may support both licensed and unlicensed communications. The APs102and STAs104also can be configured to communicate over other frequency bands such as shared licensed frequency bands, where multiple operators may have a license to operate in the same or overlapping frequency band or bands.

Each PPDU is a composite structure that includes a PHY preamble, a PHY header, and a payload in the form of a PLCP service data unit (PSDU). For example, the PSDU may include the PHY preamble and header (which may be referred to as PLCP preamble and header) as well as one or more MAC protocol data units (MPDUs). The information provided in the PHY preamble and header may be used by a receiving device to decode the subsequent data in the PSDU. In instances in which PPDUs are transmitted over a bonded channel, the preamble and header fields may be duplicated and transmitted in each of the multiple component channels. The PHY preamble may be used for packet detection, automatic gain control and channel estimation, among other uses. The format of, coding of, and information provided in the PHY header is based on the particular IEEE 802.11 protocol to be used to transmit the payload, and typically includes signaling fields (such as SIG-A and SIG-B fields) that include BSS and addressing information, such as a BSS color and a STA ID.

Aspects of transmissions may vary based on a distance between a transmitter (for example, an AP102or a STA104) and a receiver (for example, another AP102or STA104). Wireless communication devices may generally benefit from having information regarding the location or proximities of the various STAs104within the coverage area. In some examples, relevant distances may be computed using RTT-based ranging procedures. Additionally, in some implementations, APs102and STAs104may be configured to perform ranging operations. Each ranging operation may involve an exchange of FTM frames (such as those defined in the IEEE 802.11mc specification or revisions or updates thereof).

FIG.2shows a timing diagram illustrating an example process for performing a ranging operation200. The process for the ranging operation200may be cooperatively performed by two wireless devices202aand202b, which may each be an example of an AP102or a STA104.

The wireless devices202aand202bmay exchange FTM messages as part of a ranging operation200. The ranging operation200may begin with the first wireless device202atransmitting an initial FTM range request frame204at time t1,0. In some implementations, the second wireless device202bmay respond to the FTM range request204within approximately 10 milliseconds (+/−3 ms) of receiving it. Responsive to successfully receiving the FTM range request frame204at time t2,0, the second wireless device202bmay respond by transmitting a first ACK206at time t3,0, which the first wireless device202amay receive at time t4,0. The first wireless device202aand the second wireless device202bmay exchange one or more FTM bursts, which may each include multiple exchanges of FTM action frames (hereinafter simply “FTM frames”) and corresponding ACKs. One or more of the FTM range request frames204and the FTM action frames (hereinafter simply “FTM frames”) may include FTM parameters specifying various characteristics of the ranging operation200.

In the example shown inFIG.2, in a first exchange, beginning at time t1,1, the second wireless device202bmay transmit a first FTM frame208. The second wireless device202bmay record the time t1,1 as the TOD of the first FTM frame208. The first wireless device202amay receive the first FTM frame208at time t2,1 and may transmit a first acknowledgement frame (ACK)210to the second wireless device202bat time t3,1. The first wireless device202amay record the time t2,1 as the TOA of the first FTM frame208, and the time t3,1 as the TOD of the first ACK210. The second wireless device202bmay receive the first ACK210at time t4,1 and may record the time t4,1 as the TOA of the first ACK210.

Similarly, in a second exchange, beginning at time t1,2, the second wireless device202bmay transmit a second FTM frame212. The second FTM frame212may include a first field indicating the TOD of the first FTM frame208and a second field indicating the TOA of the first ACK210. The first wireless device202amay receive the second FTM frame212at time t2,2 and may transmit a second ACK214to the second wireless device202bat time t3,2. The second wireless device202bmay receive the second ACK214at time t4,2. Similarly, in a third exchange, beginning at time t1,3, the second wireless device202bmay transmit a third FTM frame216. The third FTM frame216may include a first field indicating the TOD of the second FTM frame212and a second field indicating the TOA of the second ACK214. The first wireless device202amay receive the third FTM frame216at time t2,3 and may transmit a third ACK218to the second wireless device202bat time t3,3. The second wireless device202bmay receive the third ACK218at time t4,3.

The first wireless device202amay determine a range indication based on the TODs and TOAs described above. For example, in implementations or instances in which an FTM burst includes four exchanges of FTM frames as described above, the first wireless device202amay be configured to determine a round trip time (RTT) between itself and the second wireless device202bbased on Equation 1 below.
RTT=½((Σk=12t4,k−Σk=12t1,k)−(Σk=12t3,k−Σk=12t2,k))  (1)

In some implementations, the range indication is the RTT. Additionally or alternatively, in some implementations, the first wireless device202amay determine an actual approximate distance between itself and the second wireless device202b, for example, by multiplying the RTT by 0.5 and by an approximate speed of light in the wireless medium. In such instances, the range indication may additionally or alternatively include the distance value. Additionally or alternatively, the range indication may include an indication as to whether the second wireless device202bis within a proximity (for example, a service discovery threshold) of the first wireless device202abased on the RTT. In some implementations, the first wireless device202amay transmit the range indication to the second wireless device202b, for example, in a range report224at time t1,4, which the second wireless device receives at time t2,4.

As described previously, this disclosure includes some example techniques in which the FTM protocol may be used to determine a location of a STA. An AP may determine whether to steer the STA to another AP or to another frequency band of the AP based on the location of the STA.

FIG.3shows a system diagram of an example WLAN including an AP configured to perform location aware steering based on RTT information obtained from a STA. The WLAN300shown inFIG.3is based on the example WLAN100described inFIG.1. The WLAN300includes the APs310and312and a STA314. In various examples described herein, one or more of the WLAN devices, such as the STA314, may be referred to as STAs for simplicity, regardless of whether the WLAN device is an AP or a non-AP STA. For example, the STA314may be either a non-AP STA or an AP. Furthermore, although not shown for simplicity, the WLAN300may include one or more additional STAs, which may include one or more additional APs and one or more additional non-AP STAs. In some implementations, the WLAN300may be configured as a mesh network, which may include the AP310, the AP312, and one or more additional APs. The APs310and312may be connected to a gateway device (not shown) which provides connectivity to another network. The APs310and312may be example implementations of the AP102ofFIG.1or the AP1902ofFIG.19A. The STA314may be an example implementation of the STAs104ofFIG.1or the STA1904ofFIG.19B.

Each of the APs310and312may include a measurement unit306. The measurement unit306may determine distances from the AP to STAs. For example, in the AP310, the measurement unit306may determine a distance from the AP310to the STA314. In some implementations, the measurement unit306may determine distances based on signal information. For example, in AP310, the measurement unit306may obtain signal information, such as RSSIs and beacon measurement reports, associated with the STA314. The measurement unit306may determine the distance from the AP310to the STA314based on the signal information. In some implementations, the measurement unit306also may determine distances based on RTT information. From example, in the AP310, the measurement unit306may determine a distance from the AP310to the STA314based on RTT information derived from FTM frames exchanged with the STA314. The FTM frames may include timestamps that indicate an RTT between the AP310and the STA314. Using the RTT, the measurement unit306may determine the distance between the AP310and the STA314. The measurement unit306also may obtain location information from the AP312. The location information may include a distance from the AP312to the STA314. The location information also may include a location of the STA314relative to the AP312. Using the distance from the AP310to the STA314and the location information obtained from the AP312, the measurement unit306may determine a location of the STA314. In some implementations, the location may be relative to the AP310. The AP310may share location information about the STA314with other APs in the WLAN300, such as the AP312.

Each of the APs310and312also may include a steering unit308. The steering unit308may include steering information318used in making steering decisions. In some implementations, the steering unit308may steer STAs based on locations determined by the measurement unit306and the steering information318. The steering unit308may use a location to access a steering decision in the steering information318. In some implementations, the steering information318may associate locations with steering decisions such as “steer” or “not steer.” In some implementations, the steering information indicates a target AP to which the STA will be steered (such as the AP312). The steering unit308may operate a feedback loop that updates the steering information318. For example, after steering a STA, the steering unit308may measure signal strength at the STA to determine whether steering was effective. The steering unit308may update the steering information318based on this determination. The steering information318can be implemented as a data structure in a memory device. For example, in some implementations, the steering information318may include a lookup table including steering decisions that are indexed by location or area. In some other implementations, the steering information318can be organized in any other manner suitable for storing information and include any information suitable for determining a steering decision based on a location of the STA314.

In some implementations, the STA314may begin at a first position316in the coverage area of the AP310. While in the coverage area of the AP310, the STA314has a wireless association302to the AP310. Over a time period, the STA314may move closer to a coverage area of the AP312. Over that time period, the AP310may determine the location of the STA314one or more times. To determine a location, the AP310may exchange FTM frames with the STA314. The FTM frames may include RTT information that may be used to determine an RTT between the AP310and the STA314. Based on the RTT, the AP310may determine a distance from the AP310to the STA314. The AP310also may determine a distance from the STA314to the AP312. For example, the AP310may obtain location information that indicates the distance from the STA314to the AP312via a measurement frame received from the AP312. The AP310may use the distance along with location information obtained from the AP312to determine a location of the STA314. In some implementations, the location may be relative to the AP310. In some implementations, the AP310may determine a relative location of the STA using two or more distances to known locations, such as the respective distances from the STA314to the AP312and the STA314to the AP310. If there are one or two distances to known locations, the AP310may represent the location of the STA314with a set of coordinates indicating points at which the STA314may reside. If there are three or more distances to known locations (such as distance information relating to three or more APs), the AP310may use trilateration to determine a single point representing a location of the STA314relative to the AP310. The AP310may use the location of the STA314to determine whether to steer the STA314. The AP310may periodically repeat the process of determining a location and determining whether to steer. Hence, over the time period in which the STA314is moving nearer to the AP312, the AP310may determine one or more locations for the STA314and make one or more steering decisions about the STA314. In some implementations, the AP310may access steering information that indicates whether to steer the STA314based on its location. Depending on the location of the STA314, the steering information may direct the AP310to steer the STA314to the AP312. After the AP310steers the STA314to the AP312, the STA314establishes a wireless association304with the AP312.

Steering refers to any activity which causes the device to wirelessly associate with a second AP instead of maintaining the association with a first AP. Steering also may be referred to as a re-association activity, move, transfer, relocate, transition, switch, re-position, handover, or the like. There are various techniques which can be used to steer a STA314to a particular AP or frequency band. For example, using IEEE 802.11v or other protocols, the AP310may simply request the device to re-associate to the AP312. An IEEE 802.11v configuration message may include a list of one or more other APs (for example, including the AP312) as a suggestion to the STA314to re-associate to the AP312. However, if the STA314does not support IEEE 802.11v protocols or chooses to ignore the suggestion, the AP310may use another technique to steer the STA314. For example, the AP310may send a disassociation message to the STA314or the AP310may block traffic (at least one incoming packet) for the STA314to force the STA314to re-associate with the AP312.

FIG.4shows a system diagram of an example WLAN including an AP configured to steer a STA from a first frequency band of the AP to a second frequency band of the AP. As described inFIG.3, the WLAN300may include the AP310, the AP312, and the STA314.

The AP310may support communications over a first frequency band and a second frequency band. The first frequency band may include the 2.4 GHz band and the second frequency band may include the 5 GHz band. The first frequency band may have a coverage area represented by a first area within a circle322. The second frequency band may have a coverage area represented by a second area within a circle320.

Initially, the STA314may be within the coverage area of the first frequency band and may have a wireless association402to the AP310over the first frequency band. As the STA314moves around the environment, the AP310may track movements of the STA314. The AP310may determine a distance from the AP310to the STA314based on RTT information included in FTM frames exchanged with the STA314. The FTM frames may include timestamps that may be used to derive an RTT between the AP310and the STA314. Using the RTT, the AP310may determine the distance from the AP310to the STA314. The AP310can determine whether to steer the STA314based on the steering information318(as shown inFIG.3) and the distance from the AP310to the STA314. Initially, the AP310may not steer the STA314because the STA314is connected via the first frequency band and is located within its coverage area. Over time, the AP310may track movements of the STA314by repeating this process. As the STA314moves closer to the AP310, the AP310may determine the STA314is within the coverage area of the second frequency band based on RTT information obtained from the STA314. In response, the AP310may steer the STA314from the first frequency band to the second frequency band, resulting in the wireless association404. As the AP310repeats the process of determining distances, the AP310may share the distances with the AP312. For example, the AP310may transmit a management frame to the AP312to share location information that indicates the distance from the AP310to the STA314.

FIG.5shows a system diagram of an example WLAN including APs that perform steering operations in response to signal information. As described inFIG.3, the WLAN300may include the AP310, the AP312and the STA314.

As shown inFIG.5, the AP312may have a coverage area inside the circle508. The AP310may have a coverage area inside the circle506. The ranges define an area510in which the STA314may be in the coverage area for both of the APs310and312. A steering boundary504represents a distance from the AP310at which signal strength for the STA314may be less than a signal strength threshold. In some implementations, a steering process may be triggered when the signal strength is less than the signal strength threshold. For example, the STA314may be initially connected to the AP312via a wireless association502. The AP312may monitor RSSI measurements to determine whether signal strength is less than the signal strength threshold. The AP312may determine an RSSI from one or more signals received from the STA314. The AP312may determine whether the RSSI indicates a signal strength less than the signal strength threshold. As the STA314moves away from the AP312, the signal strength may decrease. If the STA314moves past the steering boundary504, the signal strength may drop below the signal strength threshold. In response to determining the signal strength is less than the signal strength threshold, the AP312may determine a location of the STA314based on RTT information associated with the STA314and location information obtained from the AP310. For example, the AP312may exchange FTM frames with the STA314. The FTM frames may include RTT information that may be used to determine an RTT between the AP312and the STA314. Based on the RTT, the AP312may determine a distance from the AP312to the STA314. The AP312also may determine a distance from the STA314to the AP310. For example, the AP312may obtain location information that indicates the distance from the STA314to the AP310via a measurement frame received from the AP310. The AP312may determine whether to steer the STA314based on the location of the STA314. The AP312may access steering information that indicates whether to steer the STA based on its location. Depending on the location of the STA, the steering information may direct the AP312to steer the STA to the second AP. The AP312may steer the STA314to the AP310. After steering, the STA314establishes a wireless association512with the AP310. The AP312may share the distance from the AP312to the STA314and the location of the STA314with the AP310.

FIG.6depicts a process600illustrating example operations performed by an apparatus of an AP for location aware steering. The process600may be performed by a wireless communication device such as the wireless communication device1800or the electronic device2000described with reference toFIGS.18and20, respectively. In some implementations, the process600may be performed by a wireless communication device operating as or within an AP, such as one of the APs102,310,312and1902described with reference toFIGS.1,3,4,5and19A, respectively.

At block610, an apparatus of a first AP in a WLAN may determine whether a WLAN device is capable of exchanging FTM frames.

At block614, in response to determining the WLAN device is capable of exchanging FTM frames, the apparatus of the first AP may continue the process600at block618.

At block618, the apparatus of the first AP may determine a first distance from the first AP to the WLAN device based, at least in part, on FTM frames exchanged with the WLAN device.

At block620, the apparatus of the first AP may obtain a second distance from a second AP to the WLAN device.

At block630, the apparatus of the first AP may determine a location of the WLAN device based, at least in part, on the first distance and the second distance.

At block640, the apparatus of the first AP may steer the WLAN to the remote AP based, at least in part, on the location of the STA.

FIG.7depicts a process700illustrating example operations performed by an apparatus of an AP for location aware band steering. The process700may be performed by a wireless communication device such as the wireless communication device1800or the electronic device2000described with reference toFIGS.18and20, respectively. In some implementations, the process700may be performed by a wireless communication device operating as or within an AP, such as one of the APs102,310,312and1902described with reference toFIGS.1,3,4,5and19A, respectively.

At block710, the apparatus of the AP in the WLAN may determine whether a WLAN device is capable of exchanging FTM frames.

At block720, in response to determining the WLAN device is capable of exchanging FTM frames, the process continues at block730.

At block730, the apparatus of the AP may determine a distance from the AP to a WLAN device of a WLAN based, at least in part, on FTM frames exchanged with the WLAN device.

At block740, the apparatus of the AP may steer the WLAN device from a second frequency band of the AP to a first frequency band of the AP based, at least in part, on the distance.

FIG.8depicts a process800illustrating example operations for performing location aware steering with an FTM-capable STA. The process800may be performed by a wireless communication device such as the wireless communication device1800or the electronic device2000described with reference toFIGS.18and20, respectively. In some implementations, the process800may be performed by a wireless communication device operating as or within an AP, such as one of the APs102,310,312and1902described with reference toFIGS.1,3,4,5and19A, respectively. The description of the flowchart800will refer to the AP310and other devices described with reference toFIG.3.

At block810, the AP310may detect an FTM-capable STA314. In some implementations, the AP310may detect a probe request or other communication from the STA314indicating the STA314is FTM-capable. In some instances, the AP310may receive a capabilities element including a field that indicates the STA314FTM-capable. For example, the AP310may receive an Extended Capabilities element in which a field indicates the STA314is capable of acting as an FTM responder. If the STA314is capable of acting as an FTM responder, the STA314is FTM-capable. In some implementations, all STAs in the WLAN300may be FTM-capable.

At block820, the AP310may exchange FTM frames with the STA314. In some implementations, the AP310may output an FTM request for transmission to the STA314. The STA may return an FTM ACK. In response to the FTM ACK, the AP310may exchange FTM frames with the STA314. The FTM frames may include timestamps or other timing information that may be used to determine an RTT from the AP310to the STA314.

At block830, the AP310may determine a distance to the STA314based on the FTM frames. In some implementations, the AP310may determine a distance to the STA314based on the RTT associated with the FTM frames.

At block840, the AP310may obtain first location information indicating a location of the STA314relative to other APs in the WLAN300. In some implementations, the AP310may obtain the first location information from the AP312via management frames shared between the APs310and312. The location information may include a distance between the AP312and the STA314, a location of the STA314relative to the AP312, distances between other APs (not shown inFIG.3) in the WLAN300, locations relative to the other APs, and any other suitable location information.

At block850, the AP310may determine a location of the STA314based on the distance (determined at block830) and the location information. In some implementations, the AP310may determine a location of the STA314using two or more distances to known locations, such as the respective distances from the STA to the AP312and the AP310. If there are fewer than three distances, the AP310may represent the location of the STA with a set of coordinates indicating points at which the STA may reside. If there are three or more distances (such as when the distance information relates to three or more APs), the AP310may use trilateration to determine a single point representing a location of the STA314. The operations may continue in parallel at block860and block870.

At block860, the AP310may determine whether the location of the STA314is suitable for steering. In some implementations, the AP310may make this determination based on the steering information318. In some implementations, the steering information318may indicate steering decisions to be made at various locations. Using the location of the STA314as an index into the steering information318, the AP310may obtain a steering decision associated with the location. In some implementations, the steering information318may include other information, such as target APs to which the STA314will be steered, distance information related to WLAN devices, location information related to WLAN devices, signal information related to WLAN devices and any other suitable information that may provide a basis for determining whether to steer a WLAN device. If the location is not suitable for steering, operations continue at block820. If the location is suitable for steering, operations continue at block880.

At block880, the AP310may steer the STA314. In some implementations, the AP310may steer the STA314to a target AP (such as the AP312) indicated in the steering information318.

At block870, the AP310outputs second location information indicating the location of the STA314relative to the AP310. The AP312and other APs in the WLAN300(not shown) may obtain the second location information and use it to perform location aware steering.

FIG.9depicts a process900illustrating example operations for performing location aware steering in WLANs that include FTM-capable STAs and FTM-incapable STAs. The process900may be performed by a wireless communication device such as the wireless communication device1800or the electronic device2000described with reference toFIGS.18and20, respectively. In some implementations, the process900may be performed by a wireless communication device operating as or within an AP, such as one of the APs102,310,312and1902described with reference toFIGS.1,3,4,5,19A and20, respectively. The following description of the process900will refer to the AP310and other devices described with reference toFIG.3.

At block901, the AP310may determine a signal strength for a STA314.

At block902, the AP310may determine whether the signal strength for the STA314is less than a signal strength threshold. In some implementations, the AP310may determine an RSSI from one or more signals received from the STA314, and may determine a signal strength based on the RSSI. In some implementations, the AP310also may determine whether other conditions are satisfied, such as whether a network load condition is satisfied. For example, the network load condition may be satisfied when a target AP for the steering operation (such as AP312) is not overloaded. The network load condition may not be satisfied when the target AP (such as AP312) is overloaded. If the signal strength is greater than or equal to the signal strength threshold or the network load condition is not satisfied, the AP310may continue monitoring signal strength by looping back to block902. If the signal strength is less than a signal strength threshold or the network load condition is satisfied, the operations may continue at block904.

At block904, the AP310may determine whether the STA is FTM-capable. In some implementations, the AP310may receive a capabilities element including a field that indicates the STA314FTM-capable. For example, during association, the AP310may receive a capabilities element indicating the STA is capable of acting as an FTM responder. If the STA is capable of acting as an FTM responder, the STA is FTM-capable. If the STA314is FTM-capable, operations may continue at block916. If the STA is not FTM-capable, operations may continue at block908.

At block908, the AP310may request, from the STA314, information indicating a signal strength with respect to the AP310and other APs in the WLAN. In some implementations, the AP310may request a beacon measurement report that includes a received channel power indicator (RCPI) with respect to the AP310and other APs in the WLAN300. The AP also may request other IEEE 802.11k reports (such as neighbor reports) or other information indicating signal strength with respect to the AP310and other APs. IEEE 802.11k is an amendment to IEEE 802.11 standard for radio resource management. It defines and exposes radio and network information to facilitate the management and maintenance of a WLAN.

At block910, the AP310may determine whether the STA responded to the request for signal strength information. In some implementations, the STA314may provide one or more beacon measurement reports including the RCPI with respect to the AP310and other APs in the WLAN300. The STA314may provide additional IEEE 802.11k information or any other suitable information indicating signal strength with respect to APs in the WLAN300. If the STA314did not respond to the request for signal strength information, operations may continue at block908. If the STA responded to the request for signal strength information, operations may continue at block912.

At block911, the AP310may be implemented to compare signal strength received from the STA314to a signal strength of the STA314with respect to other APs in the WLAN300. In some implementations, the AP310may compare RCPI with respect to itself and the STA314with one or more RCPIs with respect to the STA314and other APs in the WLAN300.

At block912, the AP310may determine whether the difference in the signal strengths is greater than a signal strength threshold. In some implementations, the AP310may determine whether the difference in RCPIs is greater than a signal strength threshold. If the difference in the signal strengths is greater than the signal strength threshold, operations may continue at block914. If the difference in the signal strengths is less than the signal strength threshold, operations may continue at block902.

At block914, the AP310may steer the STA314. For STAs that are FTM-incapable, the AP310may steer the STA314to a target AP based on signal information (such as RCPI).

Referring back to block904, if the STA314is FTM-capable, the operations may continue at block916. At block916, the AP310may exchange FTM frames with the STA314. In some implementations, the AP310may output an FTM request for transmission to the STA314. The STA314may return an FTM ACK. In response to the FTM ACK, the AP310may exchange FTM frames with the STA314. The FTM frames may include timestamps or other timing information that may be used to determine an RTT from the AP310to the STA314.

At block918, the AP310may determine a distance to the STA314based on the FTM frames. In some implementations, the AP310may determine a distance to the STA314based on the RTT associated with the FTM frames.

At block920, the AP310may obtain location information indicating a location of the STA314relative to other APs in the WLAN300. In some implementations, the AP310may obtain the location information from the AP312via management frames shared between the APs310and312. The location information may include a distance between the AP312and the STA314, a location of the STA314relative to the AP312, distances between other APs (not shown inFIG.2) in the WLAN300, locations relative to the other APs, and any other suitable location information.

At block922, the AP310may determine a location of the STA314based on the distance (determined at block830918) and the location information. In some implementations, the AP310may determine a location of the STA314using two or more distances to known locations, such as the respective distances from the STA314to the AP312and the AP310. If there are fewer than three distances, the AP310may represent the location of the STA314with a set of coordinates indicating points at which the STA314may reside. If there are three or more distances (such as when the distance information relates to three or more APs), the AP310may use trilateration to determine a single point representing a location of the STA314.

At block924, the AP310may determine whether the location of the STA314is suitable for steering. In some implementations, the AP310may make this determination based on the steering information318. In some implementations, the steering information318may indicate steering decisions to be made at various locations. Using the location of the STA314as an index into the steering information318, the AP310may obtain a steering decision associated with the location. In some implementations, the steering information318may include other information, such as target APs to which the STA314will be steered, distance information related to WLAN devices, location information related to WLAN devices, signal information related to WLAN devices and any other suitable information that may provide a basis for determining whether to steer a WLAN device. If the location is not suitable for steering, operations continue at block902. If the location is suitable for steering, operations continue at block914.

If the operations move to block914from block924, the AP310may steer the STA314to a target AP (such as the AP312) indicated in the steering information318.

FIG.10shows a system diagram of an example WLAN including an RE configured to perform operations for placing the RE based on RTT information obtained from an AP. The WLAN1000shown inFIG.10is based on the example WLAN100described inFIG.1. The WLAN1000includes an RE1010and an AP1002. Although not shown for simplicity, the WLAN1000may include one or more STAs, which may include one or more additional APs and one or more additional non-AP STAs. In some implementations, the WLAN1000may be configured as a mesh network, which may include the AP1002, the RE1010and one or more additional APs. The AP1002may be a central AP (CAP), where a CAP is an AP that is connected to a gateway device (not shown) that provides connectivity to another network. An RE may be an AP that may extend a coverage area by receiving and retransmitting wireless signals between WLAN devices. An RE may extend the service of the CAP and may be connected to the CAP via wired or wireless links. In some implementations, the RE1010may be an AP within the WLAN1000that may receive and retransmit wireless signals between the AP1002and the STAs (not shown) in the WLAN in order to extend the coverage area of the AP1002. The RE1010and AP1002may be example implementations of the AP102ofFIG.1, the AP1902ofFIG.19Aor the STA1904ofFIG.19B.

The RE1010may include a measurement unit1018. The measurement unit1018may determine distances from the RE1010to APs based on RTT information. The measurement unit1018may determine a distance from the RE1010to the AP1002based on RTT information derived from FTM frames exchanged with the AP1002. The FTM frames may include timestamps that may be used to derive an RTT between the RE1010and the AP1002. Using the RTT, the measurement unit1018may determine a first distance between the RE1010and the AP1002.

Initially, the RE1010may be at a first location1026. A first distance threshold may indicate a minimum acceptable distance1012between the RE1010and the AP1002. A second distance threshold may indicate a maximum acceptable distance1016between the RE1010and AP1002. A distance range1008may include a range of acceptable distances between the RE1010and AP1002. The circles1004and1006illustrate a spatial relationship between the RE1010and the minimum acceptable distance1012, the maximum acceptable distance1016and the distance range1008. Initially, the RE1010is farther than the maximum acceptable distance from the AP1002(outside the circle1006) and outside the range of acceptable distances (not between the circles1004and1006).

The RE1010also may include a placement unit1020. The placement unit1020may perform operations for coarse placement of the RE1010and operations for fine placement of the RE1010. For coarse placement, the RE1010may compare the first distance from itself to the AP1002to the first distance threshold and the second distance threshold to determine whether the RE1010is located within the distance range1008(between the circles1004and1006). If the RE1010is located outside the distance range1008, the RE1010may determine whether it is located inside the minimum acceptable distance (inside the circle1004). If the RE1010is located inside the minimum acceptable distance, the RE1010may provide a coarse placement indicator indicating to move the RE1010farther from the AP1002. If the RE1010is located outside the maximum acceptable distance (outside the circle1006), the RE1010may provide a coarse placement indicator indicating to move the RE1010nearer to the AP1002.

At the first location1026, the RE1010is farther from the AP1002than the maximum acceptable distance. The placement unit1020may compare the first distance to the AP1002to the first and second distance thresholds and determine that the RE1010is farther than the maximum acceptable distance from the AP1002. In response to determining the RE1010is farther than the maximum acceptable distance from the AP1002, the RE1010may provide a coarse placement indicator indicating to move the RE1010nearer to the AP1002.

In response to the coarse placement indicator, the RE1010may be relocated to a second location1028. The RE1010may repeat operations for coarse placement until it is located in the distance range1008. Continuing with coarse placement, the RE1010may determine a second distance between itself and the AP1002, and determine whether it is located in the distance range1008. At the second location1028, the RE1010is within the distance range1008. If the RE1010is within the distance range, it presents a coarse placement indicator indicating to leave the RE1010at its current location.

The placement unit1020may include distance information1022and signal information1024. The distance information1022may indicate relationships between distances from the RE1010to the AP1002, the distance thresholds and the coarse placement indicators. For example, the relationships1030may include:1) if distance<first distance threshold (shown as DT1 inFIG.10), provide a coarse placement indicator (shown as CPI inFIG.10) to move farther from the AP1002(see distance information1030inFIG.10);2) if second distance threshold (shown as DT2 inFIG.10)≥distance≥first distance threshold (DT1), provide a coarse placement indicator to remain at the location (see distance information1030inFIG.10); and3) if distance>second distance threshold (DT2), provide a coarse placement indicator to move nearer the AP (see distance information1030inFIG.10).
The distance thresholds and relationships may be configured to expand the coverage area of the AP1002and to provide suitable signal strength to the RE1010. The distance information1022may include one or more distance thresholds, coarse placement indicators, and other information suitable for performing coarse placement of the RE1010.

In some implementations, the RE1010also may perform operations for fine placement of the RE1010. For fine placement, the RE1010may provide indications about placing the RE1010based on signal strengths. For example, the RE1010may obtain an RSSI associated with the AP1002. The placement unit1020may determine a fine placement indicator based on the RSSI, and provide the fine placement indicator to assist in placing the RE1010in the environment, as described further inFIG.11.

FIG.11shows a system diagram of an example WLAN including an RE configured to perform operations for fine placement based on signal strength information obtained from an AP.FIG.11is described with reference toFIG.10, and as described inFIG.10, the WLAN1000may include the RE1010and the AP1002.

As shown inFIG.11, the RE1010may be inside the distance range1008at location1028. The distance range1008may be the acceptable distance range for the coarse placement of the RE1010. If inside the distance range1008, the RE1010may perform operations for fine placement. For fine placement, the RE1010may determine a signal strength of the AP1002. The RE1010may establish a network association1102with the AP1002to determine a signal strength for the AP1002. The signal strength may be represented by an RSSI. The RE1010may compare the signal strengths to one or more signal strength thresholds to determine whether the signal strength is too high, too low, or within an acceptable signal strength range.

A first signal strength threshold may indicate a maximum acceptable signal strength from the AP1002. A second signal strength threshold may indicate a minimum acceptable signal strength from the AP1002. A signal strength range may indicate a range of acceptable signal strengths from the AP1002. If the signal strength is greater than the first signal strength threshold, the RE1010may provide a fine placement indicator indicating to move farther from the AP1002. If the signal strength is less than the second signal threshold, the RE1010may provide a fine placement indicator indicating to move nearer to the AP1002. If the signal strength is greater than or equal to the second signal strength threshold and less than or equal to the first signal strength threshold, the RE1010may provide a fine placement indicator indicating to leave the RE1010at its current location.

As noted, the placement unit1020may include signal information1024. The signal information1024may indicate relationships between signal strengths to the AP, the signal strength thresholds and the fine placement indicators. For example, the relationships1104may include:1) if signal strength (shown as SS inFIG.11) is greater than the first signal strength threshold (shown as SST1), provide a fine placement indicator (shown as FPI) indicating to move farther from the AP1002;2) if the signal strength is less than or equal to the first signal strength threshold (SST1) and the signal strength is greater than or equal to the second signal strength threshold (shown as SST2), provide a fine placement indicator indicating to remain at the current location; and3) if signal strength is less than the second signal strength threshold (SST2), provide a fine placement indicator indicating to move nearer the AP1002. The signal strength thresholds and relationships may be configured to expand the coverage area of the AP1002and to provide suitable signal strength to the RE1010. The signal information1024may include one or more signal strength thresholds, fine placement indicators and other information suitable for performing fine placement of the RE1010.

FIG.12depicts a process1200illustrating example operations performed by an apparatus of a first WLAN device for using RTT information to place an RE in an environment. The process1200may be performed by a wireless communication device such as the wireless communication device1800or the electronic device2000described with reference toFIGS.18and20, respectively. In some implementations, the process1200may be performed by a wireless communication device operating as or within an AP, such as one of the APs102,310,312, and1902described with reference toFIGS.1,3,4,5and19A, respectively. In some implementations, the process1200may be performed by an RE, such as the RE1010described with reference toFIGS.10and11, respectively.

At block1210, the apparatus of the first WLAN device may determine a first distance from the first WLAN device to a second WLAN device based, at least in part, on FTM frames exchanged with the second WLAN device.

At block1220, the apparatus of the first WLAN device may determine whether the first WLAN device is located within a distance range of the second WLAN device based, at least in part, on the first distance. In some implementations, the apparatus of the first WLAN device can be configured to provide coarse placement assistance. The coarse placement assistance may include a coarse placement indicator.

At block1230, the apparatus of the first WLAN device may determine a signal strength associated with the second WLAN device in response to the second WLAN device being within the distance range.

At block1240, the apparatus of the first WLAN device may compare the signal strength to one or more signal strength thresholds.

At block1250, the apparatus of the first WLAN device may provide a fine placement indicator based on the comparison.

FIG.13depicts a process1300illustrating example operations performed by an apparatus of a first WLAN device for using RTT information to place an RE in an environment. The process1300may be performed by a wireless communication device such as the wireless communication device1800or the electronic device2000described with reference toFIGS.18and20, respectively. In some implementations, the process1300may be performed by a wireless communication device operating as or within an AP, such as one of the APs102,310,312,1902and2000described with reference toFIGS.1,3,4,5,19A and20, respectively. In some implementations, the process1300may be performed by an RE, such as the RE1010described with reference toFIGS.10and11, respectively.

At block1310, the apparatus of the first WLAN device may determine a first distance from the first WLAN device to a second WLAN device based, at least in part, on FTM frames exchanged with the second WLAN device.

At block1320, the apparatus of the first WLAN device may determine whether the first WLAN device is located within a distance range of the second WLAN device based, at least in part, on the first distance. In some implementations, the apparatus of the first WLAN device can be configured to provide coarse placement assistance. The coarse placement assistance may include a coarse placement indicator.

At block1330, the apparatus of the first WLAN device may determine channel state information (CSI) associated with the second WLAN device in response to the second WLAN device being within the distance range.

At block1340, the apparatus of the first WLAN device may compare the CSI to one or more CSI thresholds.

At block1350, the apparatus of the first WLAN device may provide a fine placement indicator based on the comparison.

FIG.14depicts a process1400illustrating example operations for coarse placement of an RE in a WLAN that may have an FTM-capable AP. For an FTM-capable AP, the RE may use FTM frames in a process for coarse placement of the RE. The process1400may be performed by a wireless communication device such as the wireless communication device1800or the electronic device2000described with reference toFIGS.18and20, respectively. In some implementations, the process1400may be performed by a wireless communication device operating as or within an AP, such as the RE1010described with reference toFIGS.10and11, respectively. The description of the flowchart1400will refer to the RE1010and other devices described with reference toFIG.10.

At block1402, the RE1010may determine whether the AP1002is FTM-capable. The AP1002may receive a capabilities element indicating the RE1010is capable of acting as an FTM responder. The capabilities element may be included in a beacon or in information exchanged during association. If the RE1010receives an information element indicating the AP1002is capable of acting as an FTM responder, the AP1002is FTM-capable. Otherwise, the RE is not FTM-capable. If the AP1002is FTM-capable, operations continue at block1404. Otherwise, operations continue at block1422.

At block1404, the RE1010may exchange FTM frames with the AP1002. The FTM frames may include timestamps or other timing information that may be used to derive an RTT from the RE to the AP. The RE1010may exchange the FTM frames without creating a network association with the AP1002.

At block1406, the RE1010may determine a distance based on the FTM frames. The RE1010may determine the distance based on the RTT associated with the FTM frames.

At block1408, the RE1010may compare the distance to one or more distance thresholds. For example, the RE1010may compare the distance to two distance thresholds. A first distance threshold may indicate a minimum distance between the RE1010and the AP1002. The second distance threshold may indicate a maximum distance between the RE1010and the AP1002. The first and second distance thresholds together may indicate a distance range in which to place the RE1010. If the distance (determined at block1406) is less than the first distance threshold (at block1410), operations continue at block1412. If the first distance is greater than the first distance threshold (at block1410), operations continue at block1414.

At block1412, the RE1010may provide a coarse placement indicator indicating to move the RE farther from the AP1002. The operations continue at block1404. The RE1010may repeat operations for coarse placement until the RE1010is within the distance range of the AP1002.

At block1414, the RE1010may determine whether the distance (determined at block1406) is greater than the second distance threshold. For example, the second distance threshold may indicate a maximum distance between the RE1010and the AP1002. The RE1010may determine whether the distance between the RE1010and the AP1002is greater than the maximum distance. If the distance is greater than the second distance threshold, operations continue at block1416. If the distance is not greater than the second distance threshold, operations continue at block1418.

At block1416, the RE1010may provide a coarse placement indicator indicating to move nearer to the AP. For example, the RE1010may provide the coarse placement indicator by flashing a light indicating to move the RE1010nearer to the AP1002. Coarse placement indicators may include or be associated with any suitable media, such as audio, sound, video and flashing lights. The RE1010may present the media. The RE1010may cause presentation of the media by providing the coarse placement indicator to another device, such as a WLAN device or any suitable device that is not connected to the WLAN1000. The RE1010may repeat operations for coarse placement until the RE1010is within the distance range of the AP1002.

At block1418, the RE1010may provide a coarse placement indicator indicating to remain at the current location. For example, the RE1010may be located within a distance range of the AP1002. Because the RE1010is within the distance range, the RE1010may provide a coarse placement indicator indicating to remain at the current location.

Referring back to block1402, if the AP1002is not FTM-capable, operations continue at block1422. If the AP is not FTM-capable, the RE1010does not perform coarse placement of the RE1010based on RTT information received from the AP1002. Instead, the RE1010may use signal strength to assist in placing the RE1010in the environment. At block1422, the RE1010may create a network association with the AP1002.

At block1424, the RE1010may determine the signal strength of the AP1002. The RE1010may determine an RSSI for the AP1002.

At block1426, the RE1010may provide an indication about placing the RE1010based on the signal strength. If signal strength is too high, the RE1010may provide an indication to move farther from the AP1002. If the signal strength is too low, the RE1010may provide an indication to move closer to the AP1002. If the signal strength is within a signal strength range, the RE1010may provide an indication indicating to remain at its current location. Although the operations at blocks1422,1424and1426relate to signal strength and placing the RE1010, those operations may differ from operations for fine placement of the RE1010described herein.

FIG.15depicts example operations of a process1500for coarse and fine placement of an RE in a WLAN that includes one or more FTM-capable APs. The process1500may be performed by a wireless communication device such as the wireless communication device1800or the electronic device2000described with reference toFIGS.18and20, respectively. In some implementations, the process1500may be performed by a wireless communication device operating as or within an AP, such as the RE1010described with reference toFIGS.10and11, respectively. The description of the flowchart1500will refer to the RE1010and other devices described with reference toFIG.10.

At block1502, the RE1010may determine whether it has established a network association with the AP1002. If no network association has been established, operations continue at block1502. If the RE1010has established a network association with the AP1002, the RE1010may have received a capabilities element indicating the AP1002is capable of acting as an FTM responder. If the RE1010has established a network association with the AP1002, the operations continue at block1504.

At block1504, the RE1010may exchange FTM frames with the AP1002. The FTM frames may include timestamps or other timing information that may be used to derive an RTT from the RE1010to the AP1002.

At block1506, the RE1010may determine a distance based on the FTM frames. The RE may determine the distance based on the RTT associated with the FTM frames.

At block1508, the RE1010may compare the distance to two distance thresholds. A first distance threshold may indicate a minimum distance between the RE1010and the AP1002. The second distance threshold may indicate a maximum distance between the RE1010and the AP1002. The first and second distance thresholds together may indicate a distance range in which to place the RE1010. If the distance (determined at block1506) is less than the first distance threshold, operations continue at block1512. If the first distance is greater than the first distance threshold, the operations continue at block1514.

At block1512, the RE1010may provide a coarse placement indicator indicating to move the RE1010farther from the AP1002. The operations continue at block1504. The RE1010may repeat operations for coarse placement until the RE1010is within the distance range of the AP1002.

At block1514, the RE1010may determine whether the distance (determined at block1506) is greater than the second distance threshold. For example, the second distance threshold may indicate a maximum distance between the RE1010and the AP1002. The RE1010may determine whether the distance between the RE1010and the AP1002is greater than the maximum distance. If the distance is greater than the second distance threshold, operations continue at block1516. If the distance is not greater than the second distance threshold, the operations continue at block1518.

At block1516, the RE1010may provide a coarse placement indicator indicating to move nearer to the AP. For example, the RE1010may provide the coarse placement indicator by flashing a light indicating to move the RE1010nearer to the AP1002. The RE1010may repeat operations for coarse placement until the RE1010is within the distance range of the AP1002.

At block1518, the RE1010may provide a coarse placement indicator indicating to remain at the current location. For example, the RE1010may be located within a distance range of the AP1002. Because the RE1010is within the distance range, the RE1010may provide a coarse placement indicator indicating to remain at the current location. The process may continue at block1622which is shown inFIG.16.

FIG.16illustrates additional example operations of the process1500for coarse and fine placement of an RE in a WLAN that includes one or more FTM-capable APs. From block1518(shown inFIG.15), operations may continue at block1622.

At block1622, the RE1010may determine a signal strength associated with the AP1002. For example, the RE1010may determine an RSSI for the AP1002.

At block1624, the RE1010may determine whether signal strength is less than a first signal strength threshold. The first signal strength threshold may indicate a minimum signal strength with respect to the AP1002. If the signal strength is less than the first signal strength threshold, operations continue at block1626. Otherwise, the operations continue at block1628.

At block1628, the RE1010may determine whether the signal strength is greater than a second signal strength threshold. The second signal strength threshold may indicate a maximum signal strength with respect to the AP1002. If the signal strength is greater than the second signal strength threshold, the operations continue at block1632. If the signal strength is less than the second signal strength threshold, the operations continue at block1630.

At block1632, the RE1010may provide a fine placement indicator indicating to move farther from to the AP1002. Operations continue at block1504(shown inFIG.15).

At block1630, the RE1010may provide a fine placement indicator indicating to remain at the current location. For operations to arrive at block1630, the signal strength is within a signal strength range greater than or equal to the minimum signal strength and less than or equal to the maximum signal strength. Because the signal strength is within the signal strength range, the RE1010may provide the fine placement indicator indicating to remain at the current location.

Referring back to block1624, if the signal strength is less than the first signal strength threshold, the operations continue at block1626. At block1626, the RE1010may provide a fine placement indicator indicating to move nearer to the AP1002. The operations may continue at block1504(shown inFIG.15).

FIG.17depicts example operations of a process1700for coarse and fine placement of an RE in a WLAN using channel state information (CSI). The process1700may be performed by a wireless communication device such as the wireless communication device1800or the electronic device2000described with reference toFIGS.18and20, respectively. In some implementations, the process1700may be performed by a wireless communication device operating as or within an AP, such as the RE1010described with reference toFIGS.10and11, respectively. The description of the flowchart1700will refer to the RE1010and other devices described with reference toFIG.10.

In some implementations, the RE1010may perform operations for coarse placement shown inFIG.15. After performing block1518, the RE1010may perform the process1700, which begins at block1722. In the process1700, the RE1010may use CSI to determine a fine placement in an environment.

At block1722, the RE1010may determine the CSI from communications received from the AP1002. The CSI information may be instantaneous CSI or short-term CSI. In some implementations, the RE1010may estimate the CSI from communications received from the AP1002on a per subcarrier basis, such as on a per Orthogonal Frequency Division Multiplexing (OFDM) subcarrier basis. The CSI determined by the receiving device (such as the RE1010) also may be referred to as a Receiver CSI (or CSIR). The CSI may indicate channel properties of a communication channel between the AP1002and the RE1010on a per subcarrier basis. For example, the CSI may indicate how signals propagate from the AP1002to the RE1010and may represent the combined effects of scattering, fading, and power decay over the distance between the AP1002and the RE1010. In some implementations, the CSI may indicate a CSI amplitude on a per subcarrier basis. The CSI amplitude may indicate the signal strength on a per subcarrier basis. In some implementations, the CSI also may indicate a CSI phase on a per subcarrier basis.

At block1724, the RE1010may determine whether the CSI is less than a first CSI threshold. In some implementations, the CSI may be the CSI amplitude and the first CSI threshold may be a first CSI amplitude threshold. In some implementations, the CSI may be an aggregate of the CSI amplitudes derived on a per subcarrier basis, which may be referred to as an aggregate CSI amplitude. For example, the RE1010may determine the aggregate CSI amplitude by determining an average of the CSI amplitudes derived on a per subcarrier basis. As another example, the RE1010may determine the aggregate CSI by determining an average after a sum of the squared values of each CSI amplitude derived on a per subcarrier basis. The first CSI amplitude threshold may indicate the minimum aggregate CSI amplitude. In some implementations, the RE1010may compare the aggregate CSI amplitude to the first CSI amplitude threshold to determine whether the aggregate CSI amplitude is less than the first CSI amplitude threshold. If the CSI is less than the first CSI threshold, the flow continues at block1728. Otherwise, the flow continues at block1726.

At block1726, the RE1010may determine whether the CSI is greater than a second CSI threshold. In some implementations, the second CSI threshold may be a second CSI amplitude threshold. The second CSI amplitude threshold may indicate the maximum aggregate CSI amplitude. In some implementations, the RE1010may compare the aggregate CSI amplitude to the second CSI amplitude threshold to determine whether the aggregate CSI amplitude is greater than the second CSI amplitude threshold. If the CSI is greater than the second CSI threshold, the operations continue at block1732. If the signal strength is less than the second signal strength threshold, the operations continue at block1730.

At block1732, the RE1010may provide a fine placement indicator indicating to move farther from the AP1002. Operations continue at block1504(shown inFIG.15).

At block1730, the RE1010may provide a fine placement indicator indicating to remain at the current location. For operations to arrive at block1730, the CSI may be within a CSI range that is greater than or equal to the minimum CSI and less than or equal to the maximum CSI. Because the CSI is within the CSI range, the RE1010may provide the fine placement indicator indicating to remain at the current location.

Referring back to block1724, if the CSI is less than the first CSI threshold, the operations continue at block1728. At block1728, the RE1010may provide a fine placement indicator indicating to move nearer to the AP1002. The operations may continue at block1504(shown inFIG.15).

In some implementations, the network1000may leverage the operations related to CSI from a transmitting device (CSIT) and CSIR to provide placement assistance for the AP1002.

In some implementations, the RE1010also may use CSIT in the process for providing placement guidance. The RE1010may obtain CSIT information from the AP1002(such as at block1722). In some implementations, the RE1010may compare CSIT to CSIR to determine information related to one or more of scattering, fading and power decay (such as at block1724). This comparison of CSIT to CSIR may provide a value greater than, equal to or less than a first CSI threshold. If the value is less than the first CSI threshold (such as at block1724), the RE1010may provide a fine placement indicator to move nearer to the AP1002(such as at block1728) or the RE1010may make further comparison to a second CSI threshold (such as at block1726). If the comparison of CSIT to CSIR is greater than the second CSI threshold, the RE1010may provide a fine placement indicator to remain at its current location (such as block1730). Otherwise, the RE may provide a fine placement indicator to move farther from the AP1002(such as at block1732).

FIG.18shows a block diagram of an example wireless communication device1800. In some implementations, the wireless communication device1800can be an example of a device for use in a STA such as one of the STAs104described herein. In some implementations, the wireless communication device1800can be an example of a device for use in an AP such as the AP102described herein. The wireless communication device1800may be generally referred to as an apparatus or a wireless communication apparatus. The wireless communication device1800is capable of transmitting (or outputting for transmission) and receiving wireless communications (for example, in the form of wireless packets). For example, the wireless communication device1800can be configured to transmit and receive packets in the form of PPDUs and MPDUs conforming to an IEEE 802.11 standard, such as that defined by the IEEE 802.11-2016 specification or amendments thereof including, but not limited to, 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba and 802.11be, in addition to future 802.11 standards.

The wireless communication device1800can be, or can include, a chip, system on chip (SoC), chipset, package or device that includes one or more modems1802, for example, a Wi-Fi (IEEE 802.11 compliant) modem. In some implementations, the one or more modems1802(collectively “the modem1802”) additionally include a WWAN modem (for example, a 3GPP 4G LTE or 5G compliant modem). In some implementations, the wireless communication device1800also includes one or more radios1804(collectively “the radio1804”). In some implementations, the wireless communication device1800further includes one or more processors, processing blocks or processing elements (collectively “the processor1806”) and one or more memory blocks or elements (collectively “the memory1808”).

The modem1802can include an intelligent hardware block or device such as, for example, an application-specific integrated circuit (ASIC) among other possibilities. The modem1802is generally configured to implement a PHY layer. For example, the modem1802is configured to modulate packets and to output the modulated packets to the radio1804for transmission over the wireless medium. The modem1802is similarly configured to obtain modulated packets received by the radio1804and to demodulate the packets to provide demodulated packets. In addition to a modulator and a demodulator, the modem1802may further include digital signal processing (DSP) circuitry, automatic gain control (AGC), a coder, a decoder, a multiplexer and a demultiplexer. For example, while in a transmission mode, data obtained from the processor1806is provided to a coder, which encodes the data to provide encoded bits. The encoded bits are mapped to points in a modulation constellation (using a selected MCS) to provide modulated symbols. The modulated symbols may be mapped to a number NSSof spatial streams or a number NSTSof space-time streams. The modulated symbols in the respective spatial or space-time streams may be multiplexed, transformed via an inverse fast Fourier transform (IFFT) block, and subsequently provided to the DSP circuitry for Tx windowing and filtering. The digital signals may be provided to a digital-to-analog converter (DAC). The resultant analog signals may be provided to a frequency upconverter, and ultimately, the radio1804. In implementations involving beamforming, the modulated symbols in the respective spatial streams are precoded via a steering matrix prior to their provision to the IFFT block.

While in a reception mode, digital signals received from the radio1804are provided to the DSP circuitry, which is configured to acquire a received signal, for example, by detecting the presence of the signal and estimating the initial timing and frequency offsets. The DSP circuitry is further configured to digitally condition the digital signals, for example, using channel (narrowband) filtering, analog impairment conditioning (such as correcting for I/Q imbalance), and applying digital gain to ultimately obtain a narrowband signal. The output of the DSP circuitry may be fed to the AGC, which is configured to use information extracted from the digital signals, for example, in one or more received training fields, to determine an appropriate gain. The output of the DSP circuitry also is coupled with the demodulator, which is configured to extract modulated symbols from the signal and, for example, compute the logarithm likelihood ratios (LLRs) for each bit position of each subcarrier in each spatial stream. The demodulator is coupled with the decoder, which may be configured to process the LLRs to provide decoded bits. The decoded bits from all of the spatial streams are fed to the demultiplexer for demultiplexing. The demultiplexed bits may be descrambled and provided to the MAC layer (the processor1806) for processing, evaluation or interpretation.

The radio1804generally includes at least one radio frequency (RF) transmitter (or “transmitter chain”) and at least one RF receiver (or “receiver chain”), which may be combined into one or more transceivers. For example, the RF transmitters and receivers may include various DSP circuitry including at least one power amplifier (PA) and at least one low-noise amplifier (LNA), respectively. The RF transmitters and receivers may in turn be coupled to one or more antennas. For example, in some implementations, the wireless communication device1800can include, or be coupled with, multiple transmit antennas (each with a corresponding transmit chain) and multiple receive antennas (each with a corresponding receive chain). The symbols output from the modem1802are provided to the radio1804, which transmits the symbols via the coupled antennas. Similarly, symbols received via the antennas are obtained by the radio1804, which provides the symbols to the modem1802. In some implementations, the radio1804and the one or more antennas may form one or more network interfaces (which also may be referred to as “interfaces”).

The processor1806can include an intelligent hardware block or device such as, for example, a processing core, a processing block, a central processing unit (CPU), a microprocessor, a microcontroller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD) such as a field programmable gate array (FPGA), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor1806processes information received through the radio1804and the modem1802, and processes information to be output through the modem1802and the radio1804for transmission through the wireless medium. For example, the processor1806may implement a control plane and MAC layer configured to perform various operations related to the generation and transmission of MPDUs, frames or packets. The MAC layer is configured to perform or facilitate the coding and decoding of frames, spatial multiplexing, space-time block coding (STBC), beamforming, and OFDMA resource allocation, among other operations or techniques. In some implementations, the processor1806may generally control the modem1802to cause the modem to perform various operations described above.

The memory1808can include tangible storage media such as random-access memory (RAM) or read-only memory (ROM), or combinations thereof. The memory1808also can store non-transitory processor- or computer-executable software (SW) code containing instructions that, when executed by the processor1806, cause the processor to perform various operations described herein for wireless communication, including the generation, transmission, reception and interpretation of MPDUs, frames or packets. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein, can be implemented as one or more modules of one or more computer programs.

In some implementations, the wireless communication device1800may include a measurement unit (not shown) and a steering unit (not shown). The measurement unit and the steering unit may be similar to the measurement unit306and the steering unit308described with reference toFIG.3and may implement any of the operation for location aware steering described herein.

In some implementations, the wireless communication device1800may include a measurement unit (not shown) and a placement unit (not shown) similar to the measurement unit1018and placement unit1020described with reference toFIG.10and may implement any of the operations for coarse and fine placement described herein.

In some implementations, the measurement unit, placement unit and steering unit may be implemented by the processor1806and the memory1808. The memory1808may include computer instructions executable by the processor1806to implement the functionality of the sounding signal unit. Any of these functionalities may be partially (or entirely) implemented in hardware or on the processor1806.

In some implementations, the processor1806and the memory1808of the wireless communication device1800may be referred to as a processing system. A processing system may generally refer to a system or series of machines or components that receives inputs and processes the inputs to produce a set of outputs (which may be passed to other systems or components of, for example, one of the STAs104or one of the APs102). In some implementations, the processing system may include the processor1806, the memory1808, and one or more other components of the wireless communication device1800, such as the modem1802.

In some implementations, the processing system of a STA104may interface with other components of the STA104, and may process information received from other components (such as inputs or signals), output information to other components, etc. For example, a chip or modem of the STA104(such as the wireless communication device1800) may include a processing system and one or more interfaces. The one or more interfaces may include a first interface to receive or obtain information, and a second interface to output, transmit or provide information. In some cases, the first interface may refer to an interface between the processing system of the chip or modem and a receiver, such that the STA104may receive information or signal inputs, and the information may be passed to the processing system. In some cases, the second interface may refer to an interface between the processing system of the chip or modem and a transmitter, such that the STA104may transmit information output from the chip or modem. A person having ordinary skill in the art will readily recognize that the second interface also may obtain or receive information or signal inputs, and the first interface also may output, transmit or provide information.

In some implementations, the processing system of an AP102may interface with other components of the AP102, and may process information received from other components (such as inputs or signals), output information to other components, etc. For example, a chip or modem of the AP102(such as the wireless communication device1800) may include a processing system, a first interface to receive or obtain information, and a second interface to output, transmit or provide information. In some cases, the first interface may refer to an interface between the processing system of the chip or modem and a receiver, such that the AP102may receive information or signal inputs, and the information may be passed to the processing system. In some cases, the second interface may refer to an interface between the processing system of the chip or modem and a transmitter, such that the AP102may transmit information output from the chip or modem. A person having ordinary skill in the art will readily recognize that the second interface also may obtain or receive information or signal inputs, and the first interface also may output, transmit or provide information.

FIG.19Ashows a block diagram of an example AP1902. For example, the AP1902can be an example implementation of the AP102described herein. The AP1902includes a wireless communication device (WCD)1910. For example, the wireless communication device1910may be an example implementation of the wireless communication device1800described with reference toFIG.18. The AP1902also includes multiple antennas1920coupled with the wireless communication device1910to transmit and receive wireless communications. In some implementations, the AP1902additionally includes an application processor1930coupled with the wireless communication device1910, and a memory1940coupled with the application processor1930. The AP1902further includes at least one external network interface1950that enables the AP1902to communicate with a core network or backhaul network to gain access to external networks including the Internet. For example, the external network interface1950may include one or both of a wired (for example, Ethernet) network interface and a wireless network interface (such as a WWAN interface). Ones of the aforementioned components can communicate with other ones of the components directly or indirectly, over at least one bus. The AP1902further includes a housing that encompasses the wireless communication device1910, the application processor1930, the memory1940, and at least portions of the antennas1920and external network interface1950.

FIG.19Bshows a block diagram of an example STA1904. For example, the STA1904can be an example implementation of the STA104described herein. The STA1904includes a wireless communication device1915. For example, the wireless communication device1915may be an example implementation of the wireless communication device1800described with reference toFIG.9. The STA1904also includes one or more antennas1925coupled with the wireless communication device1915to transmit and receive wireless communications. The STA1904additionally includes an application processor1935coupled with the wireless communication device1915, and a memory1945coupled with the application processor1935. In some implementations, the STA1904further includes a user interface (UI)1955(such as a touchscreen or keypad) and a display1965, which may be integrated with the UI1955to form a touchscreen display. In some implementations, the STA1904may further include one or more sensors1975such as, for example, one or more inertial sensors, accelerometers, temperature sensors, pressure sensors, or altitude sensors. Ones of the aforementioned components can communicate with other ones of the components directly or indirectly, over at least one bus. The STA1904further includes a housing that encompasses the wireless communication device1915, the application processor1935, the memory1945, and at least portions of the antennas1925, UI1955, and display1965.

FIG.20shows a block diagram of an example electronic device for implementing aspects of this disclosure. In some implementations, the electronic device2000may be one of an AP (including any of the APs described herein), a range extender, a station (including any of the STAs described herein) or other electronic systems. The electronic device2000can include a processor2002(possibly including multiple processors, multiple cores, multiple nodes, or implementing multi-threading, etc.). The electronic device2000also can include a memory2006. The memory2006may be system memory or any one or more of the possible realizations of computer-readable media described herein. In some implementations, the processor2002and the memory2006may be referred to as the processing system. The electronic device2000also can include a bus2010(such as PCI, ISA, PCI-Express, HyperTransport®, InfiniBand®, NuBus®, AHB, AXI, etc.), and one or more network interfaces2004(which also may be referred to as “interfaces”) that can include at least one of a wireless network interface (such as a WLAN interface, a Bluetooth® interface, a WiMAX® interface, a ZigBee® interface, a Wireless USB interface, etc.) and a wired network interface (such as an Ethernet interface, a powerline communication interface, etc.). In some implementations, the electronic device2000may support multiple network interfaces—each of which is configured to couple the electronic device2000to a different communication network.

The electronic device2000may include a measurement unit306and a steering unit308, which may implement operations for location aware steering as described herein. In some implementations, the measurement unit306and the steering unit308may be distributed within the processor2002and the memory2006. The measurement unit306and the steering unit308may perform some or all the location aware steering operations described herein in this disclosure.

The electronic device2000may include a measurement unit1018, a placement unit1020, which may implement operations for coarse placement and fine placement of an RE as described herein. In some implementations, the measurement unit1018and the placement unit1020may be distributed within the processor2002and the memory2006.

The memory2006can include computer instructions executable by the processor2002to implement the functionality of the implementations described inFIGS.1-20. Any of these functionalities may be partially (or entirely) implemented in hardware or on the processor2002. For example, the functionality may be implemented with an application specific integrated circuit, in logic implemented in the processor2002, in a co-processor on a peripheral device or card, etc. Further, realizations may include fewer or additional components not illustrated inFIG.20(such as video cards, audio cards, additional network interfaces, peripheral devices, etc.). The processor2002, the memory2006, and the network interface2004are coupled to the bus2010. Although illustrated as being coupled to the bus2010, the memory2006may be coupled to the processor2002.

FIGS.1-20and the operations described herein are examples meant to aid in understanding example implementations and should not be used to limit the potential implementations or limit the scope of the claims. Some implementations may perform additional operations, fewer operations, operations in parallel or in a different order, and some operations differently.

As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c.

The various illustrative logics, logical blocks, modules, circuits and algorithm processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. The interchangeability of hardware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described throughout. Whether such functionality is implemented in hardware or software depends upon the particular application and design constraints imposed on the overall system.

The hardware and data processing apparatus used to implement the various illustrative logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, 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, or, any conventional processor, controller, microcontroller, or state machine. A processor also may 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 some implementations, particular processes and methods may be performed by circuitry that is specific to a given function.

In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed in this specification and their structural equivalents thereof, or in any combination thereof. Implementations of the subject matter described in this specification also can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on a computer storage media for execution by, or to control the operation of, data processing apparatus.

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. The processes of a method or algorithm disclosed herein may be implemented in a processor-executable software module which may reside on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program from one place to another. A storage media may be any available media that may be accessed by a computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store desired program code in the form of instructions or data structures and that may be accessed by a computer. Also, any connection can be properly termed a computer-readable medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-Ray™ disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations also can be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and instructions on a machine readable medium and computer-readable medium, which may be incorporated into a computer program product.

Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

Additionally, a person having ordinary skill in the art will readily appreciate, the terms “upper” and “lower” are sometimes used for ease of describing the Figures, and indicate relative positions corresponding to the orientation of the Figure on a properly oriented page and may not reflect the proper orientation of any device as implemented.

Certain features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one more example process in the form of a flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

In some aspects, a first method for wireless communication in a WLAN performed by an apparatus of a first AP may include determining whether a WLAN device is capable of exchanging FTM frames. The first method may include, in response to determining the WLAN device is capable of exchanging FTM frames, determining a first distance from the first AP to the WLAN device based, at least in part, on the FTM frames exchanged with the WLAN device. The first method may include, in response to determining the WLAN device is capable of exchanging FTM frames, obtaining an indication of a second distance between a second AP and the WLAN device. The first method may include, in response to determining the WLAN device is capable of exchanging FTM frames, determining a location of the WLAN device based, at least in part, on the first distance and the second distance. The first method may include, in response to determining the WLAN device is capable of exchanging FTM frames, steering the WLAN device to the second AP based, at least in part, on the location of the WLAN device.

The first method may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other methods described elsewhere herein.

In a first aspect, the location is a relative location of the WLAN device with respect to the first AP and the second AP.

In a second aspect, alone or in combination with the first aspect, the first method may include determining a signal strength of a signal received from the WLAN device. In the second aspect, the first method may include determining that the signal strength is less than a signal strength threshold, where determining whether a WLAN device is capable of exchanging FTM frames is in response to determining that the signal strength is less than a signal strength threshold.

In a third aspect, alone or in combination with one or more of the first and second aspects, determining whether a WLAN device is capable of exchanging FTM frames may include obtaining, from the WLAN device, a capabilities element indicating the WLAN device is capable of exchanging FTM frames.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, determining the first distance is based, at least in part, on FTM frames exchanged with the WLAN device may include outputting the FTM frames for transmission to the WLAN device, obtaining FTM ACKs associated with the FTM frames from the WLAN device, determining a RTT based, at least in part, on the FTM frames and the FTM ACKs, and determining the first distance based, at least in part, on the RTT.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, steering the WLAN device may include selecting steering information based, at least in part, on the location of the WLAN device, where the steering information indicates whether to steer the WLAN device based, at least in part, on the location. In the fifth aspect, steering the WLAN device may include determining to steer the WLAN device to the second AP based, at least in part, on the steering information.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, obtaining the indication of the second distance may include receiving an FTM range report that indicates the second distance.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the first method may include outputting an FTM request for transmission to the WLAN device. In the seventh aspect, the first method may include obtaining an FTM acknowledgement from the WLAN device. In the seventh aspect, the first method may include, in response to obtaining the FTM acknowledgment, exchanging the FTM frames with the WLAN device.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the first method may include obtaining, from the second AP, distance information including the indication of the second distance.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the first method may also include obtaining distance information from other APs in the WLAN, the distance information indicating other distances from the other APs to the WLAN device.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the first method may include determining a third distance from the first AP to the WLAN device based, at least in part, on additional FTM frames exchanged with the WLAN device. In the tenth aspect, the first method may include steering the WLAN device from a first frequency band of the first AP to a second frequency band of the first AP based, at least in part, on the third distance.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the first method may include after steering the WLAN device, determining a signal strength of communications received from the WLAN device. In the eleventh aspect, the first method may include, after steering the WLAN device, determining that the signal strength is greater than a signal strength threshold. In the eleventh aspect, the first method may include, after steering the WLAN device, updating steering information to indicate the location and the signal strength.

In some aspects, a second method for wireless communication in a WLAN performed by an apparatus of an AP may include determining whether a WLAN device is capable of exchanging FTM frames. The second method may include, in response to determining the WLAN device is capable of exchanging the FTM frames, determining a distance from the AP to the WLAN device based, at least in part, on FTM frames exchanged with the WLAN device. The second method may include, in response to determining the WLAN device is capable of exchanging the FTM frames, steering the WLAN device from a first frequency band of the AP to a second frequency band of the AP based, at least in part, on the distance.

The second method may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other methods described elsewhere herein.

In a first aspect, the second method may include determining a signal strength of a signal received from the WLAN device. In the first aspect, the second method may include determining that the signal strength is less than a signal strength threshold, where determining whether a WLAN device is capable of exchanging FTM frames is in response to determining that the signal strength is less than a signal strength threshold.

In a second aspect, alone or in combination with the first aspect, the second method may include determining the AP has a wireless association with the WLAN device via the first frequency band. In the second aspect, the second method may include determining that the WLAN device is outside a first range of the first frequency band of the AP based, at least in part, on the distance.

In a third aspect, alone or in combination with one or more of the first and second aspects, the second method may include determining the WLAN is within a second range of the second frequency band.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the second method may include outputting the FTM frames for transmission to the WLAN device. In the fourth aspect, the second method may include obtaining FTM ACKs from the WLAN device.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, steering the WLAN device may include selecting steering information based, at least in part, on the distance from the AP to the WLAN device. In the fifth aspect, the steering the WLAN device may include determining to steer the WLAN device to the second frequency band based, at least in part, on the steering information.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the method may include after steering the WLAN device, determining a signal strength of communications received from the WLAN device. In the sixth aspect, the method may include, after steering the WLAN device, determining that the signal strength is greater than a signal strength threshold. In the sixth aspect, the method may include, after steering the WLAN device, updating steering information to indicate the distance and the signal strength.

In some aspects, an apparatus of a first AP for wireless communication may include a processor configured to determine whether a WLAN device of a WLAN is capable of exchanging FTM frames. The processor may be configured to, in response to a determination that the WLAN device is capable of exchanging the FTM frames, determine a first distance from the first AP to the WLAN device based, at least in part, on FTM frames exchanged with the WLAN device. The processor may be configured to, in response to a determination that the WLAN device is capable of exchanging the FTM frames, obtain an indication of a second distance between a second AP and the WLAN device. The processor may be configured to, in response to a determination that the WLAN device is capable of exchanging the FTM frames, determine a location of the WLAN device based, at least in part, on the first distance and the second distance. The apparatus of the first AP may include an interface configured to output a message to steer the WLAN device to the second AP based, at least in part, on the location of the WLAN device.

The apparatus of the first AP may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other apparatuses described elsewhere herein.

In a first aspect, the processor may be further configured to determine a signal strength of a signal received from the WLAN device, and determine that the signal strength is less than a signal strength threshold, where the determination whether a WLAN device is capable of exchanging FTM frames is in response to determining that the signal strength is less than a signal strength threshold.

In a second aspect, alone or in combination with the first aspect, the processor may be further configured to obtain the indication of the second distance from an FTM range report.

In a third aspect, alone or in combination with one or more of the first and second aspects, the interface may be further configured to output the FTM frames for transmission to the WLAN device, and obtain FTM ACKs from the WLAN device. In the third aspect, the processor may be further configured to determine an RTT based on the FTM frames and the FTM ACKs, and determine the first distance based on the RTT.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the processor may be further configured to select steering information based, at least in part, on the location of the WLAN device, where the steering information indicates whether to steer the WLAN device based, at least in part, on the location. In the fourth aspect, the processor may be further configured to determine to steer the WLAN device to the second AP based, at least in part, on the steering information.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the processor may be further configured to determine the location is outside a first coverage area of a first frequency band of the first AP and within a second coverage area of a second frequency band of the first AP. In the fifth aspect, the processor may be further configured to steer the WLAN device from the first frequency band of the first AP to the second frequency band of the first AP based, at least in part, on the location.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the processor may be further configured to determine a third distance from the first AP to the WLAN device based, at least in part, on additional FTM frames exchanged with the WLAN device. In the sixth aspect, the processor may be further configured to steer the WLAN device from a first frequency band of the first AP to a second frequency band of the first AP based, at least in part, on the third distance.

In some aspects, an apparatus for wireless communication of an AP may include a processor configured to determine whether a WLAN device of a WLAN is capable of exchanging FTM frames. The processor may be configured to, in response to a determination that the WLAN device is capable of exchanging the FTM frames, determine a distance from the AP to the WLAN device based, at least in part, on FTM frames exchanged with the WLAN device. The processor may be configured to, in response to a determination that the WLAN device is capable of exchanging the FTM frames, steer the WLAN device from a first frequency band of the AP to a second frequency band of the AP based, at least in part, on the distance.

The apparatus for wireless communication of an AP may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other apparatuses described elsewhere herein.

In a first aspect, the processor may be further configured to determine a signal strength of a signal received from the WLAN device. In the first aspect, the processor may be further configured to determine that the signal strength is less than a signal strength threshold, where the determination whether a WLAN device is capable of exchanging FTM frames is in response to determining that the signal strength is less than a signal strength threshold.

In a second aspect, alone or in combination with the first aspect, the processor may be further configured to determine the AP has a wireless association with the WLAN device via the first frequency band, and determine that the WLAN device is outside a first coverage area of the first frequency band of the AP based, at least in part, on the distance.

In a third aspect, alone or in combination with one or more of the first and second aspects, the processor may be further configured to select steering information based, at least in part, on the distance of the WLAN device, and determine to steer the WLAN device to the second frequency band based, at least in part, on the steering information.