Wireless devices and communication methods

Abstract

The invention relates to a wireless communication machine and method. The invention proposes methods, components, devices, and systems that can determine the transmit opportunity duration (TXOP) for the primary channel (O-Primary) for transmitters and receivers that may have different (asymmetric) observation states regarding the primary channel (M-Primary). The example method, implemented at the first wireless node, generally involves switching from communication via the first primary channel to communication via the second primary channel, after detecting an overlapping basic service set (BSS), outputting, for transmission on the second primary channel, the first frame indicating the required transmit opportunity duration (TXOP) associated with the second primary channel, receiving, after outputting the first frame indicating the allowed duration for the TXOP, and communicating with at least the second wireless node for the allowed duration for the TXOP.

Description

TXOP DURATION NEGOTIATION TO ADDRESS ASYMMETRIC CHANNELVIEW FOR MULTIPLE PRIMARY CHANNELSCROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to Indian Patent Application No. 202341072929, filed October 26, 2023, which is assigned to the assignee hereof and hereby expressly incorporated by reference in its entirety as if fully set forth below and for all applicable purposes.TECHNICAL FIELD

[0002] This disclosure relates generally to wireless communication, and more specifically, to aspects related to mechanisms to determine a transmit opportunity (TXOP) duration when a transmitter and receiver have asymmetric channel views for networks that support multiple channels to contend for access to a wireless medium.DESCRIPTION OF THE RELATED TECHNOLOGY

[0003] A wireless local area network (WLAN) may be formed by one or more wireless access points (APs) that provide a shared wireless communication medium for use by multiple client devices also referred to as wireless stations (STAs). The basic building block of a WLAN conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards is a Basic Service Set (BSS), which is managed by an AP. Each BSS is identified by a Basic Service Set Identifier (BSSID) that is advertised by the AP. An AP periodically broadcasts beacon frames to enable any STAs within wireless range of the AP to establish or maintain a communication link with the WLAN.

[0004] In some WLAN scenarios, devices share access to a wireless medium. In such scenarios, contention-based channel access is a mechanism used to share the wireless medium. This mechanism allows multiple devices to access the same wireless channel without a centralized coordinator, making it suitable for scenarios with a variable number of devices.

[0005] For example, devices that want to transmit data first listen to the wireless channel. This procedure is referred to as carrier sensing, where a device first checks if the channel is idle or busy. If the channel is sensed as busy, indicating another device iscurrently transmitting, the carrier sensing device will wait for an idle period before attempting to transmit.SUMMARY

[0006] The systems, methods and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0007] One aspect provides a method for wireless communications by a first wireless device, related to selecting a transmit opportunity (TXOP) duration when switching from communicating via a first primary channel to communicating via a second primary channel, after a detection of an overlapping basic service set (BSS). The first wireless device may output, for transmission on the second primary channel, a first frame indicating a requested duration for a transmission opportunity (TXOP) associated with the second primary channel; obtain, after outputting the first frame, an indication of an allowed duration for the TXOP; and communicate with at least a second wireless node in accordance with the allowed duration for the TXOP.

[0008] One aspect provides a method for wireless communications by a second wireless device, related to selecting a transmit opportunity (TXOP) duration when switching from communicating via a first primary channel to communicating via a second primary channel, after a detection of an overlapping basic service set (BSS). The second wireless device may obtain, on the second primary channel, a first frame indicating a requested duration for a transmission opportunity (TXOP) associated with the second primary channel; output, for transmission in response to the first frame, an indication of an allowed duration for the TXOP; and communicate with at least a first wireless node in accordance with the allowed duration for the TXOP.

[0009] Other aspects provide: an apparatus operable, configured, or otherwise adapted to perform any one or more of the aforementioned methods and / or those described elsewhere herein; a non-transitory, computer-readable media comprising instructions that, when executed by a processor of an apparatus, cause the apparatus to perform the aforementioned methods as well as those described elsewhere herein; a computer program product embodied on a computer-readable storage medium comprising code for performing the aforementioned methods as well as those described elsewhere herein; and / or an apparatus comprising means for performing the aforementioned methods as well as those described elsewhere herein. By way of example,an apparatus may comprise a processing system, a device with a processing system, or processing systems cooperating over one or more networks.

[0010] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings and the claims. Note that the relative dimensions of the following figures may not be drawn to scale.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The appended figures depict certain features of the various aspects described herein and are not to be considered limiting of the scope of this disclosure.

[0012] Figure 1 shows a pictorial diagram of an example wireless communication network.

[0013] Figure 2 shows a pictorial diagram of an example bandwidth configuration for a wireless local area network (WLAN).

[0014] Figures 3A and 3B show an example of primary and secondary channel selection for a given channel.

[0015] Figures 4 and 5 show examples of channel access using multiple primary channels, in which aspects of the present disclosure may be utilized.

[0016] Figures 6 shows an example of asymmetric channel views that may be addressed in accordance with aspects of the present disclosure.

[0017] Figure 7 shows an example call flow diagram for transmit opportunity (TXOP) duration determination, in accordance with aspects of the present disclosure.

[0018] Figures 8 and 9 show examples of TXOP duration determination, in accordance with aspects of the present disclosure.

[0019] Figure 10 shows a flowchart illustrating an example process performable at a first wireless node that supports TXOP duration determination related to aspects of the present disclosure.

[0020] Figure 11 shows a flowchart illustrating an example process performable at a second wireless node that supports TXOP duration determination related to aspects of the present disclosure.

[0021] Figure 12 shows a block diagram of an example wireless communication device that supports aspects of the present disclosure.

[0022] Like reference numbers and designations in the various drawings indicate like elements.DETAILED DESCRIPTION

[0023] The following description is directed to some particular examples for the purposes of describing 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. Some or all of the described examples 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 Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, the IEEE 802.15 standards, the Bluetooth® standards as defined by the Bluetooth Special Interest Group (SIG), or the Long Term Evolution (LTE), 3G, 4G or 5G (New Radio (NR)) standards promulgated by the 3rdGeneration Partnership Project (3 GPP), among others. The described examples can be implemented in any device, system or network that is capable of transmitting and receiving RF signals according to one or more of the following technologies or techniques: code division multiple access (CDMA), time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC- FDMA), spatial division multiple access (SDMA), rate-splitting multiple access (RSMA), multi-user shared access (MUSA), single-user (SU) multiple-input multiple-output (MIMO) and multi-user (MU)-MIMO (MU-MIMO). The described examples also can be implemented using other wireless communication protocols or RF signals suitable for use in one or more of a wireless personal area network (WPAN), a wireless local area network (WLAN), a wireless wide area network (WWAN), a wireless metropolitan area network (WMAN), or an internet of things (loT) network.

[0024] Various aspects relate generally to wireless communication and more particularly to techniques for determining transmit opportunity (TXOP) durations for networks that support multiple channels to contend for access to a wireless medium.

[0025] Contention-based channel access generally refers to a mechanism used to share the wireless medium. Devices that want to transmit data first listen to the wireless channel. This procedure is referred to as carrier sensing, where a device first checks if the channel is idle or busy. If the channel is sensed as busy, indicating another device iscurrently transmitting, the carrier sensing device will wait for an idle period before attempting to transmit.

[0026] Contention-based channel access may be used to share access in WLANs that support relatively large bandwidths. For example, IEEE 802.11be Extremely High Throughput (EHT), also known as Wi-Fi 7, has defined bandwidth support for up to 320 MHz. Within the large bandwidth, one 20 MHz channel is designated as a primary channel.

[0027] For example, Figure 2 depicts a diagram 200 for an example bandwidth configuration for a 160 MHz bandwidth, in which the 20 MHz primary channel is labeled P20. A Wi-Fi device contends for access only on the primary channel and access to wider bandwidths (no matter how large) is contingent on access to the primary channel.

[0028] Therefore, if an overlapping basic service set (OBSS) station (STA) occupies the primary channel, another (In-BSS) STA may detect an OBSS transmission 202 when performing channel access on the primary channel. Because access to the wider bandwidth (for In-BS transmissions 206) is contingent on access to the primary channel, a remainder of the wide bandwidth 204 remains unutilized, which contributes to lower- throughput and longer latencies.

[0029] In some WLAN scenarios, however, a WLAN device may be capable of monitoring additional 20 MHz channel(s) within the operating bandwidth to contend for channel access. Such monitoring may be performed sequentially or in parallel. With sequential monitoring, when one 20 MHz primary channel is found Busy, the device switches to the next 20 MHz channel to contend for access. With parallel monitoring, the device can monitor each 20 MHz channel simultaneously. In such scenarios, the initial primary channel is referred to as a Main Primary (M-Primary) channel, while an additional 20 MHz channel / sub channel is referred to as an Opportunistic Primary (O- Primary) channel.

[0030] One potential challenge with multi-primary channel access, is how to determine a transmit opportunity (TXOP) duration when wireless nodes (e.g., access point (AP) and non-AP STAs) utilizing multiple channels for channel access have asymmetrical views of one or more of the channels. A TXOP duration generally refers to a limited time period of contention-free channel access available to a channel-owning station, as other devices may set a network allocation vector or NAV based on the TXOP duration (and stay off the medium until a NAV timer expires). One benefit of a TXOPduration mechanism is that it may increase throughput and reduce delay by eliminating contention periods between transmissions.

[0031] The duration of a TXOP on an O-Primary channel is typically determined based on a TXOP duration of an OBSS transmission detected on an M-Primary channel. In large networks, an AP and a STA to have different (asymmetrical) views of the M- Primary channel, which could result in different TXOP durations. For example, an AP and STA may detect different OBSS PPDUs. There may be some ambiguity in TXOP duration for an O-Primary channel if an OBSS TXOP duration / NAV observed at a receiver (AP or STA) is shorter than a TXOP duration / NAV observed at a transmitter (STA or AP).

[0032] This ambiguity may make it unclear how long a receiver should wait until PPDU reception is complete which may create certain issues. For example, if the receiver is an AP, waiting for PPDU reception to complete (and transmit an acknowledgment / ACK) may cause backward compatibility issues. On the other hand, the receiver terminating the PPDU reception early and switching back to the M-Primary channel may result in performance loss on the O-Primary channel which diminishes the potential gains of the multi-primary channel access feature.

[0033] Aspects of the present disclosure, however, provide a mechanism where a transmitter and receiver may effectively negotiate a TXOP for an O-Primary channel. As will be described in greater detail below, a transmitter and receiver may exchange information on a TXOP duration allowed on the O-Primary channel. In some cases, a NAV for the O-Primary channel may be set after this exchange of information is complete.

[0034] Particular aspects of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In some examples, the described techniques can be used to set a TXOP duration for an O-Primary channel in a manner that prevents over-suppression of other devices contending for access on the O-Primary channel. As a result, the techniques may result in improved system performance and better resource utilization.

[0035] Although some aspects of the present disclosure are described in the context of multi-primary channel access, with an M-Primary channel and one or more O-Primary channels, the concepts and techniques described herein apply more broadly apply to any type of system with different types of channels or links used to contend for channel access. In some implementations, the techniques described herein may be applied in systemswhere the M-primary channel and the O-primary channel are sub-channels within an operating bandwidth (such as in multi-primary channel access). In some other implementations, the techniques described herein may be applied where the M-primary channel and the O-primary channel are different links (such as in enhanced multi-link single radio (eMLSR) AP systems).

[0036] Figure 1 shows a pictorial diagram of an example wireless communication network 100. According to some aspects, the wireless communication network 100 can be an example of a wireless local area network (WLAN) such as a Wi-Fi network. For example, the wireless communication network 100 can be a network implementing at least one of the IEEE 802.11 family of wireless communication protocol standards (such as defined by the IEEE 802.11-2020 specification or amendments thereof including, but not limited to, 802.11ay, 802.11ax, 802.11az, 802.11ba, 802.11bd, 802.11be, 802.11bf, and 802.11bn). In some other examples, the wireless communication network 100 can be an example of a cellular radio access network (RAN), such as a 5G or 6G RAN that implements one or more cellular protocols such as those specified in one or more 3GPP standards. In some other examples, the wireless communication network 100 can include a WLAN that functions in an interoperable or converged manner with one or more cellular RANs to provide greater or enhanced network coverage to wireless communication devices within the wireless communication network 100 or to enable such devices to connect to a cellular network’s core, such as to access the network management capabilities and functionality offered by the cellular network core.

[0037] The wireless communication network 100 may include numerous wireless communication devices including at least one wireless access point (AP) 102 and any number of wireless stations (STAs) 104. While only one AP 102 is shown in Figure 1, the wireless communication network 100 can include multiple APs 102. The AP 102 can be or represent various different types of network entities including, but not limited to, a home networking AP, an enterprise-level AP, a single-frequency AP, a dual-band simultaneous (DBS) AP, a tri -band simultaneous (TBS) AP, a standalone AP, a non- standalone AP, a software-enabled AP (soft AP), and a multi-link AP (also referred to as an AP multi-link device (MLD)), as well as cellular (such as 3GPP, 4G LTE, 5G or 6G) base stations or other cellular network nodes such as a Node B, an evolved Node B (eNB), a gNB, a transmission reception point (TRP) or another type of device or equipment included in a radio access network (RAN), including Open-RAN (O-RAN) network entities, such as a central unit (CU), a distributed unit (DU) or a radio unit (RU).

[0038] Each of the STAs 104 also 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 examples. The STAs 104 may represent various devices such as mobile phones, other handheld or wearable communication devices, netbooks, notebook computers, tablet computers, laptops, Chromebooks, augmented reality (AR), virtual reality (VR), mixed reality (MR) or extended reality (XR) wireless headsets or other peripheral devices, wireless earbuds, other wearable devices, display devices (for example, TVs, computer monitors or video gaming consoles), video game controllers, navigation systems, music or other audio or stereo devices, remote control devices, printers, kitchen appliances (including smart refrigerators) or other household appliances, key fobs (for example, for passive keyless entry and start (PKES) systems), Internet of Things (loT) devices, and vehicles, among other examples.

[0039] A single AP 102 and an associated set of STAs 104 may be referred to as a basic service set (BSS), which is managed by the respective AP 102. Figure 1 additionally shows an example coverage area 108 of the AP 102, which may represent a basic service area (BSA) of the wireless communication network 100. The BSS may be identified by STAs 104 and other devices by a service set identifier (SSID), as well as a basic service set identifier (BSSID), which may be a medium access control (MAC) address of the AP 102. The AP 102 may periodically broadcast beacon frames (“beacons”) including the BSSID to enable any STAs 104 within wireless range of the AP 102 to “associate” or reassociate with the AP 102 to establish a respective communication link 106 (hereinafter also referred to as a “Wi-Fi link”), or to maintain a communication link 106, with the AP 102. For example, the beacons can include an identification or indication of a primary channel used by the respective AP 102 as well as a timing synchronization function (TSF) for establishing or maintaining timing synchronization with the AP 102. The AP 102 may provide access to external networks to various STAs 104 in the wireless communication network 100 via respective communication links 106.

[0040] To establish a communication link 106 with an AP 102, each of the STAs 104 is 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, 45 GHz, or 60 GHz bands). To perform passive scanning, a STA 104 listens for beacons, which are transmitted by respective APs 102 at periodic time intervals referred to as target beacon transmission times (TBTTs). To perform active scanning, a STA 104 generatesand sequentially transmits probe requests on each channel to be scanned and listens for probe responses from APs 102. Each STA 104 may identify, determine, ascertain, or select an AP 102 with which to associate in accordance with the scanning information obtained through the passive or active scans, and to perform authentication and association operations to establish a communication link 106 with the selected AP 102. The selected AP 102 assigns an association identifier (AID) to the STA 104 at the culmination of the association operations, which the AP 102 uses to track the STA 104.

[0041] As a result of the increasing ubiquity of wireless networks, a STA 104 may have the opportunity to select one of many BSSs within range of the STA 104 or to select among multiple APs 102 that together form an extended service set (ESS) including multiple connected BSSs. For example, the wireless communication network 100 may be connected to a wired or wireless distribution system that may enable multiple APs 102 to be connected in such an ESS. As such, a STA 104 can be covered by more than one AP 102 and can associate with different APs 102 at different times for different transmissions. Additionally, after association with an AP 102, a STA 104 also may periodically scan its surroundings to find a more suitable AP 102 with which to associate. For example, a STA 104 that is moving relative to its associated AP 102 may perform a “roaming” scan to find another AP 102 having more desirable network characteristics such as a greater received signal strength indicator (RS SI) or a reduced traffic load.

[0042] In some cases, STAs 104 may form networks without APs 102 or other equipment other than the STAs 104 themselves. 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 network such as the wireless communication network 100. In such examples, while the STAs 104 may be capable of communicating with each other through the AP 102 using communication links 106, STAs 104 also can communicate directly with each other via direct wireless communication links 110. Additionally, two STAs 104 may communicate via a direct communication link 110 regardless of whether both STAs 104 are associated with and served by the same AP 102. In such an ad-hoc system, one or more of the STAs 104 may assume the role filled by the AP 102 in a BSS. Such a STA 104 may be referred to as a group owner (GO) and may coordinate transmissions within the ad-hoc network. Examples of direct wireless communication links 110 include Wi-Fi Direct connections,connections established by using a Wi-Fi Tunneled Direct Link Setup (TDLS) link, and other P2P group connections.

[0043] In some networks, the AP 102 or the STAs 104, or both, may support applications associated with high throughput or low-latency requirements, or may provide lossless audio to one or more other devices. For example, the AP 102 or the STAs 104 may support applications and use cases associated with ultra-low-latency (ULL), such as ULL gaming, or streaming lossless audio and video to one or more personal audio devices (such as peripheral devices) or AR / VR / MR / XR headset devices. In scenarios in which a user uses two or more peripheral devices, the AP 102 or the STAs 104 may support an extended personal audio network enabling communication with the two or more peripheral devices. Additionally, the AP 102 and STAs 104 may support additional ULL applications such as cloud-based applications (such as VR cloud gaming) that have ULL and high throughput requirements.

[0044] As indicated above, in some implementations, the AP 102 and the STAs 104 may function and communicate (via the respective communication links 106) according to one or more of the IEEE 802.11 family of wireless communication protocol standards. These standards define the WLAN radio and baseband protocols for the physical (PHY) and MAC layers. The AP 102 and STAs 104 transmit and receive wireless communications (hereinafter also referred to as “Wi-Fi communications” or “wireless packets”) to and from one another in the form of PHY protocol data units (PPDUs).

[0045] Each PPDU is a composite structure that includes a PHY preamble and a payload that is in the form of a PHY service data unit (PSDU). The information provided in the preamble may be used by a receiving device to decode the subsequent data in the PSDU. In instances in which a PPDU is transmitted over a bonded or wideband channel, the preamble fields may be duplicated and transmitted in each of multiple component channels. The PHY preamble may include both a legacy portion (or “legacy preamble”) and a non-legacy portion (or “non-legacy preamble”). The legacy preamble may be used for packet detection, automatic gain control and channel estimation, among other uses. The legacy preamble also may generally be used to maintain compatibility with legacy devices. The format of, coding of, and information provided in the non-legacy portion of the preamble is associated with the particular IEEE 802.11 wireless communication protocol to be used to transmit the payload.

[0046] The APs 102 and STAs 104 in the WLAN 100 may transmit PPDUs over an unlicensed spectrum, which may be a portion of spectrum that includes frequency bandstraditionally used by Wi-Fi technology, such as the 2.4 GHz, 5 GHz, 6 GHz, 45 GHz, and 60 GHz bands. Some examples of the APs 102 and STAs 104 described herein also may communicate in other frequency bands that may support licensed or unlicensed communications. For example, the APs 102 or STAs 104, or both, also may be capable of communicating over licensed operating bands, where multiple operators may have respective licenses to operate in the same or overlapping frequency ranges. Such licensed operating bands may map to or be associated with frequency range designations of FR1 (410 MHz - 7.125 GHz), FR2 (24.25 GHz - 52.6 GHz), FR3 (7.125 GHz - 24.25 GHz), FR4a or FR4-1 (52.6 GHz - 71 GHz), FR4 (52.6 GHz - 114.25 GHz), and FR5 (114.25 GHz - 300 GHz).

[0047] Each of the frequency bands may include multiple sub-bands and frequency channels (also referred to as subchannels). For example, PPDUs conforming to the IEEE 802.1 In, 802.1 lac, 802.1 lax, 802.11be and 802.11bn standard amendments may be transmitted over one or more of the 2.4 GHz, 5 GHz, or 6 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 may be transmitted over physical channels having bandwidths of 40 MHz, 80 MHz, 160 MHz, 240 MHz, 320 MHz, 480 MHz, or 640 MHz by bonding together multiple 20 MHz channels.

[0048] In some examples, the AP 102 or the STAs 104 of the WLAN 100 may implement Extremely High Throughput (EHT) or other features compliant with current and future generations of the IEEE 802.11 family of wireless communication protocol standards (such as the IEEE 802.1 Ibe and 802.1 Ibn standard amendments) to provide additional capabilities over other previous systems (for example, High Efficiency (HE) systems or other legacy systems). For example, the IEEE 802.1 Ibe standard amendment introduced 320 MHz channels, which are twice as wide as those possible with the IEEE 802.1 lax standard amendment. Accordingly, the AP 102 or the STAs 104 may use 320 MHz channels enabling double the throughput and network capacity, as well as providing rate versus range gains at high data rates due to linear bandwidth versus log SNR trade-off. EHT and newer wireless communication protocols (such as the protocols referred to as or associated with the IEEE 802.1 Ibn standard amendment) may support flexible operating bandwidth enhancements, such as broadened operating bandwidths relative to legacy operating bandwidths or more granular operation relative to legacy operation. For example, an EHT system may allow communications spanningoperating bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 240 MHz, and 320 MHz. EHT systems may support multiple bandwidth modes such as a contiguous 240 MHz bandwidth mode, a contiguous 320 MHz bandwidth mode, a noncontiguous 160+160 MHz bandwidth mode, or a noncontiguous 80+80+80+80 (or “4x80”) MHz bandwidth mode.

[0049] In some examples in which a wireless communication device (such as the AP 102 or the STA 104) operates in a contiguous 320 MHz bandwidth mode or a 160+160 MHz bandwidth mode, signals for transmission may be generated by two different transmit chains of the wireless communication device each having or associated with a bandwidth of 160 MHz (and each coupled to a different power amplifier). In some other examples, two transmit chains can be used to support a 240 MHz / 160+80 MHz bandwidth mode by puncturing 320 MHz / 160+160 MHz bandwidth modes with one or more 80 MHz subchannels. For example, signals for transmission may be generated by two different transmit chains of the wireless communication device each having a bandwidth of 160 MHz with one of the transmit chains outputting a signal having an 80 MHz subchannel punctured therein. In some other examples in which the wireless communication device may operate in a contiguous 240 MHz bandwidth mode, or a noncontiguous 160 + 80 MHz bandwidth mode, the signals for transmission may be generated by three different transmit chains of the wireless communication device, each having a bandwidth of 80 MHz. In some other examples, signals for transmission may be generated by four or more different transmit chains of the wireless communication device, each having a bandwidth of 80 MHz.

[0050] In noncontiguous examples, the operating bandwidth may span one or more disparate sub-channel sets. For example, the 320 MHz bandwidth may be contiguous and located in the same 6 GHz band or noncontiguous and located in different bands or regions within a band (such as partly in the 5 GHz band and partly in the 6 GHz band).

[0051] In some examples, the AP 102 or the STA 104 may benefit from operability enhancements associated with EHT and newer generations of the IEEE 802.11 family of wireless communication protocol standards. For example, the AP 102 or the STA 104 attempting to gain access to the wireless medium of WLAN 100 may perform techniques (which may include modifications to existing rules, structure, or signaling implemented for legacy systems) such as clear channel assessment (CCA) operation based on EHT enhancements such as increased bandwidth, puncturing, or refinements to carrier sensing and signal reporting mechanisms.

[0052] Access to the shared wireless medium is generally governed by a distributed coordination function (DCF). With a DCF, there is generally no centralized master device allocating time and frequency resources of the shared wireless medium. On the contrary, before a wireless communication device, such as an AP 102 or a STA 104, is permitted to transmit data, it may wait for a particular time and then contend for access to the wireless medium. The DCF is implemented through the use of time intervals (including the slot time (or “slot interval”) and the inter-frame space (IFS). IFS provides priority access for control frames used for proper network operation. Transmissions may begin at slot boundaries. Different varieties of IFS exist including the short IFS (SIFS), the distributed IFS (DIFS), the extended IFS (EIFS), and the arbitration IFS (AIFS). The values for the slot time and IFS may be provided by a suitable standard specification, such as one or more of the IEEE 802.11 family of wireless communication protocol standards.

[0053] In some examples, the wireless communication device (such as the AP 102 or the STA 104) may implement the DCF through the use of carrier sense multiple access (CSMA) with collision avoidance (CA) (CSMA / CA) techniques. According to such techniques, before transmitting data, the wireless communication device may perform a clear channel assessment (CCA) and may determine (for example, identify, detect, ascertain, calculate, or compute) that the relevant wireless channel is idle. The CCA includes both physical (PHY-level) carrier sensing and virtual (MAC-level) carrier sensing. Physical carrier sensing is accomplished via a measurement of the received signal strength of a valid frame, which is then compared to a threshold to determine (for example, identify, detect, ascertain, calculate, or compute) whether the channel is busy. For example, if the received signal strength of a detected preamble is above a threshold, the medium is considered busy. Physical carrier sensing also includes energy detection. Energy detection involves measuring the total energy the wireless communication device receives regardless of whether the received signal represents a valid frame. If the total energy detected is above a threshold, the medium is considered busy.

[0054] Virtual carrier sensing is accomplished via the use of a network allocation vector (NAV), which effectively serves as a time duration that elapses before the wireless communication device may contend for access even in the absence of a detected symbol or even if the detected energy is below the relevant threshold. The NAV is reset each time a valid frame is received that is not addressed to the wireless communication device. When the NAV reaches 0, the wireless communication deviceperforms the physical carrier sensing. If the channel remains idle for the appropriate IFS, the wireless communication device initiates a backoff timer, which represents a duration of time that the device senses the medium to be idle before it is permitted to transmit. If the channel remains idle until the backoff timer expires, the wireless communication device becomes the holder (or “owner”) of a transmit opportunity (TXOP) and may begin transmitting. The TXOP is the duration of time the wireless communication device can transmit frames over the channel after it has “won” contention for the wireless medium. The TXOP duration may be indicated in the U-SIG field of a PPDU. If, on the other hand, one or more of the carrier sense mechanisms indicate that the channel is busy, a MAC controller within the wireless communication device will not permit transmission.

[0055] Each time the wireless communication device generates a new PPDU for transmission in a new TXOP, it randomly selects a new backoff timer duration. The available distribution of the numbers that may be randomly selected for the backoff timer is referred to as the contention window (CW). There are different CW and TXOP durations for each of the four access categories (ACs): voice (AC VO), video (AC VI), background (AC BK), and best effort (AC BE). This enables particular types of traffic to be prioritized in the network.

[0056] In some other examples, the wireless communication device (for example, the AP 102 or the STA 104) may contend for access to the wireless medium of WLAN 100 in accordance with an enhanced distributed channel access (EDC A) procedure. A random channel access mechanism such as EDCA may afford high-priority traffic a greater likelihood of gaining medium access than low-priority traffic. The wireless communication device using EDCA may classify data into different access categories. Each AC may be associated with a different priority level and may be assigned a different range of random backoffs (RBOs) so that higher priority data is more likely to win a TXOP than lower priority data (such as by assigning lower RBOs to higher increases the likelihood that low-latency data traffic will gain access to a shared wireless medium during a given contention period, unpredictable outcomes of medium access contention operations may prevent low-latency applications from achieving certain levels of throughput or satisfying certain latency requirements.Overview of Channel Numbering

[0057] A primary channel generally refers to a channel that a STA monitors for contention-based channel access. As described above with reference to Figure 2, in WLANs that support relatively large bandwidths, one 20 MHz channel is designated as a primary channel. This channel may be referred to as primary 20 or, as labeled in Figure 2, simply P20.

[0058] Selection of the bandwidth for the P20 channel typically decides all other channels. For example, in the case of a 160 MHz operating bandwidth, selection of P20 may determine a secondary 20 MHz channel (S20), a primary 40 MHz channel (P40), a secondary 40 MHz channel (S40), a primary 80 MHz channel (P80), and a secondary 80 MHz channel (S80).

[0059] Figures 3A and 3B show an example of primary and secondary channel selection for a given channel. Diagram 300 of Figure 3 A shows how the bandwidth of a 160 MHz channel number 163 may be allocated to form different 80 MHz channels (155 and 171), 40 MHz channels (151, 159, 167, and 175), and 20 MHz channels (149, 153, 157, 161, 165, 169, 173, and 177). Particular channel frequencies for these channels may be determined based on a set of equations, determined by the operating bandwidth and a channel selection parameter X.

[0060] Table 350 of Figure 3B shows the possible combinations of channel frequencies for P20, S20, P40, S40, P80, and S80 channels for the 160 MHz bandwidth channel 163 shown in Figure 3 A. As illustrated, selecting the parameter X is essentially the same as choosing the channel frequency for P20. For example, choosing X = 1 means P20 is 153 and vice versa, resulting in S20 = 149, P40 = 151), S40 = 159, P80 = 155, and S80 = 171.Overview of Multiple Primary Channels

[0061] As noted above, in some WLAN scenarios, a STA may be capable of monitoring additional 20 MHz channel(s) within the operating bandwidth to contend for channel access. In such scenarios, the initial primary channel is referred to as a Main Primary (M-Primary or M-P20) channel, while an additional 20 MHz channel / sub channel is referred to as an Opportunistic Primary (O-Primary or O-P20) channel.

[0062] Figure 4 shows an example diagram 400 of channel access for an AP and a STA (STA1) using sequential monitoring of multiple primary channels. As illustrated, with sequential monitoring, when the M-Primary channel is found Busy (as indicated bydetection of a transmission 402 in an OBSS), the devices may switch to an O-Primary to contend for access.

[0063] The devices may detect the M-Primary channel is busy by decoding a PPDU and determining that the PPDU is an OBSS PPDU. The devices may also store an OBSS network allocation vector (NAV) indicated by a duration field in the OBSS PPDU, to determine when to switch back to the M-Primary channel.

[0064] In some cases, the AP may send an RTS frame 404 so that STA1 switches to the O-Primary channel. STA1 may respond with a CTS frame 406 to confirm that STA1 has switched to the O-Primary channel. As illustrated, the devices may switch their main radios back to the M-Primary channel before the OBSS NAV expires (e.g., after a data transmission acknowledged by an ACK 408).

[0065] As illustrated in Figure 5, with parallel monitoring, the device can monitor each 20 MHz channel simultaneously. For example, a STA may have an auxiliary (AUX) radio that can be used for parallel monitoring. In the illustrated example, the AP sees the OBSS PPDU 502 on the M-Primary channel and switches its main radio to the O-Primary channel and initiates a TXOP. While STA1 does not see the OBSS PPDU 502 on the M- Primary channel, it may still monitor the O-Primary channel, via its AUX radio. Therefore, it may detect the RTS frame from the AP and switch to the O-Primary channel accordingly.Aspects Related to TXOP Duration Determination for O-Primary Channels

[0066] As described above, one potential challenge with multi-primary channel access, is how to determine a transmit opportunity (TXOP) duration when wireless nodes utilizing multiple channels for channel access have asymmetrical views of one or more of the channels.

[0067] The notion of asymmetrical channel views may be understood with reference to diagram 600 of Figure 6. As illustrated, an AP may detect a first OBSS transmission 602 on a primary channel (such as an M-Primary channel) and switch to a non-primary channel (such as an O-Primary channel). Similarly, a STA detects a second OBSS transmission 604 on the primary channel and switches to the non-primary channel.

[0068] As illustrated, the first OBSS transmission 602 may end sooner than the OBSS transmission 604. As a result, the AP and STA may have determined different TXOP durations to apply when they switch to a non-primary channel to communicate. In the illustrated example, the STA has data to transmit (as indicated by the solid line). Due tothe different views of the primary channel, the AP’s TXOP duration may expire sooner than the STA’s TXOP duration, and the AP may, thus, return to the primary channel before the data transmission 606 from the STA is completed.

[0069] Thus, in this example, if the receiver / AP were to terminate the PPDU reception early and switch back to the M-Primary channel, a performance loss on the O- Primary channel may occur. This performance loss diminishes the potential gains of the multi-primary channel feature.

[0070] Aspects of the present disclosure, however, provide a mechanism where a transmitter and receiver may effectively negotiate a TXOP duration allowed for an O- Primary channel. As will be described in greater detail below, a transmitter and receiver may exchange information on a TXOP duration allowed on the O-Primary channel. In some cases, a NAV for the O-Primary channel may be set after this exchange of information is complete. As a result, a transmitter and receiver may be in agreement regarding a TXOP duration when switching to an O-Primary channel.

[0071] TXOP determination in accordance with aspects of the present disclosure may be understood with reference to the example call flow diagram 700 of Figure 7.

[0072] In some aspects, one of the wireless nodes and OBSS AP shown in Figure 7 may be examples of the AP 102 (e.g., an AP STA) depicted and described with respect to Figure 1. In some aspects, one of the wireless nodes shown in Figure 7 may be an example of a (non-AP) STA 104 depicted and described with respect to Figure 1.

[0073] As indicated at 702, the first wireless node (e.g., an AP or STA) may detect an OBSS transmission on a first Primary Channel (e.g., an M-Primary Channel).

[0074] The first wireless node may then transmit a first frame to the second wireless node indicating a requested TXOP duration, determined based on the detected OBSS transmission.

[0075] As indicated at 704, after receiving the first frame, the second wireless node may determine an allowed TXOP duration. The second wireless node may then transmit a second frame that indicates the allowed TXOP duration.

[0076] As indicated at 706 and 708, the first and second wireless nodes may then communicate with each other in accordance with the allowed TXOP duration.

[0077] Figures 8 and 9 show examples of TXOP duration determination, in accordance with aspects of the present disclosure, based on an exchange of information between a transmitter and receiver on a TXOP duration allowed on the O-Primary channel.

[0078] Referring first to the diagram 800 of Figure 8, the illustrated example assumes the transmitter is a STA, while the receiver is an AP. The STA may be considered a transmitter in this context because it has an amount of data to transmit and, thus, can know a corresponding TXOP duration to request for that data transmission.

[0079] After detecting an OBSS transmission on a primary channel (M-Primary), the transmitter and receiver switch to a non-primary channel (O-Primary) exchange information on TXOP duration allowed on O-Primary. In the illustrated example, the receiver (AP) detects OBSS transmission 802, while the transmitter (STA) detects OBSS transmission 804.

[0080] The exchange of information may involve any suitable type of frames. As illustrated, according to certain aspects, the exchange of information regarding the TXOP duration allowed on the O-Primary channel may occur in an initial Control frame (ICF) on the O-Primary channel. In ICF generally refers to a frame that is sent to confirm that a peer STA has switched to the O-Primary channel. Depending on the capability of the peer, the ICF may also be designed to cause a STA's main radio to switch to the O-Primary channel, if it has not yet switched (e.g., if it has not yet detected the OBSS).

[0081] The NAV on the O-Primary channel may be set once the exchange of ICF (and its response from the AP) is complete. In some cases, the response from the AP may indicate an allowed TXOP duration for the O-Primary channel and the NAV is set based on the allowed TXOP duration.

[0082] According to certain aspects, the exchange of TXOP duration information may occur after the ICF frame exchange is complete. More generally, the TXOP duration negotiation could happen in any short frame exchange (such as RTS / CTS, MU-RTS, BSRP / BSR, BAR / BA, MU-BAR / BA) and could even occur on an M-Primary channel.

[0083] As illustrated in Figure 8, the allowed TXOP duration may be significantly shorter than the TXOP duration requested by the STA. In such cases, the STA may adjust the duration of the PPDU or TXOP or both accordingly. This approach may prevent oversuppression of other wireless nodes contending for access to the medium.

[0084] In some cases, a PPDU size may not need to be adjusted. For example, if the TXOP duration requested was based on a sequence of n PPDUs ("PPDU1 — ACK1 — PPDU2 — ACK2 — — PPDU-N — ACK-n"), after receiving the allowed duration from the receiver, the transmitter may simply adjust the number of PPDUs (e.g., by limiting the sequence to "PPDU1 - ACK1 - PPDU2 - ACK2 - .. - PPDU-m - ACK-m", where m < n).

[0085] In some cases, the allowed TXOP duration on the O-Primary may be determined as a minimum of the TXOP duration requested by the transmitter and a TXOP duration allowed at the receiver:TXOP o-Primary = min (TXOP requested by TX, TXOP allowed at RX).In this context, the TXOP requested by the transmitter may be a minimum duration required to transmit an amount of data (e.g., to flush a number of PPDUs) and a TXOP duration allowed at the transmitter:TXOP requested by TX = min (time required to flush the PPDUs, TXOP allowed at TX).

[0086] The TXOP durations allowed at the transmitter and receiver may depend on the OBSS transmissions (804 and 802) they detected.

[0087] For example, the TXOP duration allowed at the transmitter may equal a remaining duration of OBSS transmission 802 as seen on the M-Primary channel by the transmitter. The TXOP allowed at the receiver may equal a remaining NAV of the OBSS STA as seen on M-Primary by the receiver (based on OBSS transmission 804). The duration of OBSS transmissions (802 / 804) may be based on (i) a value indicated in the Duration field of the frame received from the OBSS STA (which is the NAV), or (ii) a value indicated in a Length subfield of the L-SIG field of the PPDU received from the OBSS STA.

[0088] As will be described in greater detail below, if there is more than one receiver (e.g., if the transmitter is an AP transmitting to multiple STAs), then the allowed TXOP duration on the O-Primary channel may be based on a minimum of allowed TXOP durations at all receivers may be considered.

[0089] As illustrated in Figure 8, after receiving an ACK 808 for its PPDU 806, the STA may switch back to M-Primary channel. In some cases, the transmitter may switch after receiving an ACK for a final PPDU. In such cases, where a sequence of PPDUs are transmitted (e.g., via SIFS bursting), all of the PPDUs and ACKs may need to finish within the allowed TXOP duration. In some cases, the PPDU transmission may be adjusted to account for a transition delay needed to switch the radio from the O-Primary to the M-Primary.

[0090] As noted above, the TXOP duration requested by the transmitter may be indicated on the O-Primary channel using an ICF. The ICF may be a type of trigger frame, such as a multi-user (MU) request to send (MU-RTS), buffer status report poll (BSRP), or MU block acknowledgment request (MU-BAR).

[0091] In some cases, the duration field of the ICF may be set to a relatively small value. The value in this field is used by neighboring STAs to set their NAV value. As illustrated in Figure 8, the Duration value may only protect the response frame (e.g., CTS frames labeled and applicable SIFS). One benefit of this approach is that neighboring STAs will not unnecessarily set their NAV to a large value if the requested TXOP is not permissible at the receiver (resulting in a smaller allowed TXOP duration).

[0092] The TXOP requested by the transmitter may be indicated in a field inside the ICF. For example, the “UL Length” field in the Common Info field of the Trigger frame may be used to specify the requested TXOP duration. Alternatively, the “Allocation Duration” field in the User Info field of the Trigger frame may be used to specify the requested TXOP duration. In some cases, a newly defined subfield in the Common Info or User Info field of the Trigger frame or an A-Control field defined for a Trigger frame may be used to specify the requested TXOP duration.

[0093] As indicated above, the transmitter may compute the value of the requested TXOP duration based on the remaining duration of the OBSS transmission and / or how much data it has in its queue. For example, if the remaining duration of the OBSS is greater than the time to flush the transmitter PPDUs, the requested TXOP duration may be set to the time to flush the transmitter PPDUs. On the other hand, if the remaining duration of the OBSS is less than the time to flush the transmitter PPDUs, the requested TXOP duration may be set to remaining duration of the OBSS.

[0094] Aspects of the present disclosure may be utilized in single user (SU) and multiuser (MU) scenarios.

[0095] In an SU scenario, which implies that the transmitter is initiating a TXOP to communicate with only one STA (e.g., UL or DL SU TXOP), the allowed TXOP duration may be indicated in the “Duration” field of the frame sent in response to the ICF. Neighboring STAs on the O-Primary channel will set their NAVs based on this value.

[0096] In an MU scenario, which implies that the transmitter is initiating a TXOP to communicate with more than one STA (e.g., an AP initiating a DL MU TXOP), the “Duration” field of the frame sent in response to the ICF is set to a small value. This value may be computed, for example, as:Duration (response) = Duration (ICF) - SIFS - time taken to transmit response.As an alternative, the value may be set to protect the following SIFS. As noted above, one benefit of this approach is that neighboring STAs will not unnecessarily set their NAV to a large value if the allowed TXOP at some other STA is not large enough.

[0097] In some cases, the TXOP allowed at the receiver may be indicated in a field inside the response frame. For example, the TXOP allowed at the receiver may be indicated in an A-Control field included in the response frame.

[0098] Certain computations may be common to both MU and SU scenarios. For example, the receiver may compute an allowed TXOP duration based on the remaining OBSS duration (e.g., OBSS NAV) it sees and the TXOP duration requested by the transmitter. For example, if the remaining OBSS duration is greater than the TXOP duration requested by the transmitter, the allowed TXOP duration may equal the TXOP duration requested by transmitter. On the other hand, if the remaining OBSS duration is less than the TXOP duration requested by the transmitter, the allowed TXOP duration may equal the remaining OBSS duration.

[0099] Referring again to Figure 8, the transmitter (STA in this example) may limit the TXOP duration on the O-Primary to allowed TXOP duration (e.g., the value indicated by the receiver in the Duration field of the frame sent in response to the ICF).

[0100] In the MU case, described in greater detail below with reference to Figure 9, if the allowed TXOP duration at one or more receivers (e.g., STA1 or STA2) is smaller than the TXOP duration preferred by the transmitter, then the transmitter may drop those receivers from subsequent frames.

[0101] In general, the transmitter may computes the allowed TXOP duration as the minimum of the TXOPs allowed at the receivers served in the subsequent frames. In the SU case, the Duration value setting in the subsequent frames may follow a baseline behavior. In the MU case, the Duration value of the first frame sent after receiving the response frame may be set according to the allowed TXOP indicated by the receivers. If the transmitter is a STA, it can switch back to M-Primary after the TXOP ends.

[0102] Referring to the diagram 900 of Figure 9, the illustrated example assumes the transmitter is an AP, while multiple STAs are receivers.

[0103] After detecting OBSS transmissions on the primary channel (M-Primary), the transmitter and receivers switch to a non-primary channel (O-Primary) exchange information on TXOP duration allowed on O-Primary. In the illustrated example, the AP detects OBSS transmission 904, STA1 detects OBSS transmission 902, and STA2 detects OBSS transmission 912.

[0104] As illustrated in Figure 9, when the transmitter is an AP, it may switch back to the M-Primary channel after the TXOP ends (after receiving ACK 908 from STA1and / or ACK 918 from STA2). As an alternative, the AP may initiate a TXOP with another STA after the TXOP ends.

[0105] In certain cases, the type of TXOP duration determination for O-Primary channels may be limited to either the SU case or the MU case. For example, it may be possible that only the MU case is defined and, in such cases, the MU case may be reused for the SU case (e.g., with the number of receivers = 1). As another example, only the SU case may be defined.

[0106] MU scenarios are often applicable for DL TXOPs. In such cases, if non-AP STAs remain on the O-Primary channel beyond the OBSS NAV seen on the M-Primary channel, there is no compatibility issue with other (legacy) devices, since the non-AP STA may not communicate (e.g., exchange data frames) with STAs other than the associated AP. However, the STA(s) may be required to perform some form of medium synchronization recovery on the M-Primary channel after switching back to the M- Primary channel. In some scenarios, if the non-AP STA participates in frame exchanges with other non-AP STAs (e.g., in P2P frame exchanges), a non-AP STA may indicate to the AP that it is not capable of extending frame exchanges on the O-Primary channel beyond the TXOP of the OBSS STA on the M-Primary channel.

[0107] As described above, one potential benefit of the mechanism proposed herein is that the duration of O-Primary TXOP may be determined without over-suppressing neighboring STAs (e.g., without their NAV being set beyond an actual usage of the channel), since the NAV is typically set by the transmitter and / or receiver only after the duration of the allowed TXOP is exchanged between the transmitter and receiver in fields carried inside the request and response frames (such as the ICF).

[0108] However, other options of the proposed solution are also possible, with possibly different impact on suppression of neighboring STAs.

[0109] For example, according to a first option, a transmitter may indicate the requested TXOP duration in the “Duration” field. The receiver may indicate the allowed TXOP duration in the “Duration” field and the transmitter may adjust the TXOP duration on the O-Primary channel based on the value indicated by the receiver. This option has the potential to cause over-suppression if the OBSS NAV seen at the transmitter is larger than OBSS NAV seen at the receiver.

[0110] According to a second option, the transmitter may set a short NAV, but may not indicate the requested TXOP duration. The receiver may set the allowed TXOP duration in the “Duration” field, and the transmitter can initiate a TXOP according to thisindicated allowed TXOP duration. This option also has the potential to cause oversuppression, for example, if the transmitter does not have enough PPDUs in its queue to utilize the entire allowed TXOP duration.[OHl] While certain examples of applying the techniques proposed herein are in the context of multi-primary channel access and on the O-Primary channel, in general, the TXOP duration negotiation mechanisms proposed herein may be broadly applied for other use cases, as well.

[0112] One example is that a receiver may have some in-device coexistence considerations, such as an impending Bluetooth transmission for which it needs to free up its antennas / resources from other wireless (e.g., 802.11) transmissions. In such cases, the receiver may want to terminate a TXOP sooner than what the transmitter requested. In this scenario, the negotiation procedure proposed herein may be applicable. In other words, the negotiation may be performed on an M-Primary channel for various reasons (such as in-device coexistence). In fact, in some cases, the transmitter and receiver performing the negotiation may not even support multi-primary channel access.

[0113] FIG. 10 shows a flowchart illustrating an example process 1000 performable at a first wireless node, according to certain aspects of the present disclosure. The operations of the process 1000 may be implemented by a wireless AP or a wireless STA, or its components as described herein. For example, the process 1000 may be performed by a wireless communication device, such as the wireless communication device 1200 described with reference to Figure 12, operating as or within a wireless AP or a wireless STA. In some examples, the process 1000 may be performed by a wireless AP or a wireless STA, such as one of the wireless APs 102 or one of the wireless STAs 104 described with reference to Figure 1.

[0114] Process 1000 begins at step 1005 with switching from communicating via a first primary channel to communicating via a second primary channel, after (e.g., based on) a detection of an overlapping basic service set (BSS).

[0115] Process 1000 then proceeds to step 1010 with outputting, for transmission on the second primary channel, a first frame indicating a requested duration for a transmission opportunity (TXOP) associated with the second primary channel.

[0116] Process 1000 then proceeds to step 1015 with obtaining, after outputting (e.g., in response to) the first frame, an indication of an allowed duration for the TXOP.

[0117] Process 1000 then proceeds to step 1020 with communicating with at least a second wireless node in accordance with the allowed duration for the TXOP

[0118] In one aspect, process 1000, or any aspect related to it, may be performed by an apparatus, such as wireless communications device 1200 of Figure 12, which includes various components operable, configured, or adapted to perform the process 1000. Wireless communications device 1200 is described below in further detail.

[0119] Note that Figure 10 is just one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.

[0120] FIG. 11 shows a flowchart illustrating an example process 1100 performable at a second wireless node, according to certain aspects of the present disclosure. The operations of the process 1100 may be implemented by a wireless AP or a wireless STA, or its components as described herein. For example, the process 1100 may be performed by a wireless communication device, such as the wireless communication device 1200 described with reference to Figure 12, operating as or within a wireless AP or a wireless STA. In some examples, the process 1100 may be performed by a wireless AP or a wireless STA, such as one of the wireless APs 102 or one of the wireless STAs 104 described with reference to Figure 1.

[0121] Process 1100 begins at step 1105 with switching from communicating via a first primary channel to communicating via a second primary channel, after (e.g., based on) a detection of an overlapping basic service set (BSS).

[0122] Process 1100 then proceeds to step 1110 with obtaining, on the second primary channel, a first frame indicating a requested duration for a transmission opportunity (TXOP) associated with the second primary channel.

[0123] Process 1100 then proceeds to step 1115 with outputting, for transmission after obtaining the first frame, an indication of an allowed duration for the TXOP.

[0124] Process 1100 then proceeds to step 1120 with communicating with at least a first wireless node in accordance with the allowed duration for the TXOP.

[0125] In one aspect, process 1100, or any aspect related to it, may be performed by an apparatus, such as wireless communications device 1200 of Figure 12, which includesvarious components operable, configured, or adapted to perform the process 1100. Wireless communications device 1200 is described below in further detail.

[0126] Note that Figure 11 is just one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.

[0127] Figure 12 shows a block diagram of an example wireless communication device 1200, according to some aspects of the present disclosure. In one example, the wireless communication device 1200 is configured or operable to perform a process 1000, described with reference to Figure 10 and / or a process 1100 described with reference to Figure 11. In various examples, the wireless communication device 1200 can be a chip, SoC, chipset, package or device that may include: one or more modems (such as a Wi-Fi (IEEE 802.11) modem or a cellular modem such as 3GPP 4G LTE or 5G compliant modem); one or more processors, processing blocks or processing elements (collectively “the processor”); one or more radios (collectively “the radio”); and one or more memories or memory blocks (collectively “the memory”).

[0128] In some examples, the wireless communication device 1200 can be a device for use in an AP, such as AP 102 described with reference to Figure 1. In some examples, the wireless communication device 1200 can be a device for use in a STA, such as STA 104 described with reference to Figure 1. In some other examples, the wireless communication device 1200 can be an AP or a STA that includes such a chip, SoC, chipset, package or device as well as multiple antennas. The wireless communication device 1200 is capable of transmitting and receiving wireless communications in the form of, for example, wireless packets. For example, the wireless communication device can be configured or operable to transmit and receive packets in the form of physical layer PPDUs and MPDUs conforming to one or more of the IEEE 802.11 family of wireless communication protocol standards. In some examples, the wireless communication device 1200 also includes or can be coupled with an application processor which may be further coupled with another memory. In some examples, the wireless communication device 1200 further includes at least one external network interface that enables communication with a core network or backhaul network to gain access to external networks including the Internet.

[0129] The wireless communication device 1200 includes at least a switching component 1202, an obtaining component 1204, an outputting component 1206, acommunicating component 1208, an adjusting component 1210, a calculating component 1212, an initiating component 1214, and an indicating component 1216. Portions of one or more of the components 1202, 1204, 1206, 1208, 1210, 1212, 1214, and / or 1216 may be implemented at least in part in hardware or firmware. For example, the obtaining component 1202 may be implemented at least in part by a modem. In some examples, at least some of the components 1202, 1204, 1206, 1208, 1210, 1212, 1214, and / or 1216 are implemented at least in part by a processor and as software stored in a memory. For example, portions of one or more of the components 1202, 1204, 1206, 1208, 1210, 1212, 1214, and / or 1216 can be implemented as non-transitory instructions (or “code”) executable by the processor to perform the functions or operations of the respective module.

[0130] In some implementations, the processor may be a component of 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, the wireless communication device 1200). For example, a processing system of the wireless communication device 1200 may refer to a system including the various other components or subcomponents of the wireless communication device 1200, such as the processor, or a transceiver, or a communications manager, or other components or combinations of components of the wireless communication device 1200. The processing system of the wireless communication device 1200 may interface with other components of the wireless communication device 1200, and may process information received from other components (such as inputs or signals) or output information to other components. For example, a chip or modem of the wireless communication device 1200 may include a processing system, a first interface to output information and a second interface to obtain information. In some implementations, the first interface may refer to an interface between the processing system of the chip or modem and a transmitter, such that the wireless communication device 1200 may transmit information output from the chip or modem. In some implementations, the second interface may refer to an interface between the processing system of the chip or modem and a receiver, such that the wireless communication device 1200 may obtain information or signal inputs, and the information may be passed to the processing system. A person having ordinary skill in the art will readily recognize that the first interface also may obtain information or signal inputs, and the second interface also may output information or signal outputs.EXAMPLE CLAUSES

[0131] Implementation examples are described in the following numbered clauses:

[0132] Clause 1 : A method for wireless communication at a first wireless node, comprising: switching from communicating via a first primary channel to communicating via a second primary channel, after a detection of an overlapping basic service set (BSS); outputting, for transmission on the second primary channel, a first frame indicating a requested duration for a transmission opportunity (TXOP) associated with the second primary channel; obtaining, after outputting the first frame, an indication of an allowed duration for the TXOP; and communicating with at least a second wireless node in accordance with the allowed duration for the TXOP

[0133] Clause 2: The method of Clause 1, wherein: the first primary channel comprises a main primary channel; and the at least one second primary channel comprises an opportunistic primary channel.

[0134] Clause 3: The method of any one of Clauses 1-2, wherein the communicating comprises: outputting, for transmission in accordance with the allowed duration for the TXOP, at least one physical layer protocol data unit (PPDU)]; and switching, after the end of the TXOP, from the second primary channel back to the first primary channel.

[0135] Clause 4: The method of Clause 3, further comprising and adjusting at least one of a duration of the at least one PPDU or a duration of the TXOP, in accordance with the allowed duration for the TXOP

[0136] Clause 5: The method of any one of Clauses 1-4, wherein the first frame comprises an initial control frame (ICF).

[0137] Clause 6: The method of any one of Clauses 1-5, further comprising and calculating the requested duration based on at least one of: a duration of an overlapping BSS transmission, or a quantity of data in a queue associated with the transmitter device

[0138] Clause 7: The method of any one of Clauses 1-6, wherein: the TXOP comprises a multi-user (MU) TXOP; and the allowed duration is based on at least one of the requested duration, a short interframe space (SIFS) associated with the second wireless node, or a time associated with transmission of the indication.

[0139] Clause 8: The method of any one of Clauses 1-7, wherein the first wireless node comprises an access point (AP) device.

[0140] Clause 9: The method of any one of Clauses 1-8, further comprising and initiating, after the allowed duration ends, a second TXOP with a third wireless node.

[0141] Clause 10: The method of any one of Clauses 1-9, wherein the first wireless node comprises a non-access point (AP) STA device.

[0142] Clause 11 : The method of any one of Clauses 1-10, wherein the first frame comprises a trigger frame that includes at least one of an uplink length field, an allocation duration field, a duration field, or a subfield that indicates the requested duration.

[0143] Clause 12: The method of any one of Clauses 1-11, wherein the allowed duration is indicated in at least one of: an uplink length field, an allocation duration field, a duration field, or a subfield of a second frame obtained in response to the first frame.

[0144] Clause 13: A method for wireless communication at a second wireless node, comprising: switching from communicating via a first primary channel to communicating via a second primary channel, after a detection of an overlapping basic service set (BSS); obtaining, on the second primary channel, a first frame indicating a requested duration for a transmission opportunity (TXOP) associated with the second primary channel; outputting, for transmission after obtaining the first frame, an indication of an allowed duration for the TXOP; and communicating with at least a first wireless node in accordance with the allowed duration for the TXOP

[0145] Clause 14: The method of Clause 13, wherein: the first primary channel comprises a main primary channel; and the at least one second primary channel comprises an opportunistic primary channel.

[0146] Clause 15: The method of any one of Clauses 13-14, wherein the communicating comprises: obtaining, in accordance with the allowed duration for the TXOP, at least one physical layer protocol data unit (PPDU); and switching, after the end of the TXOP, from the second primary channel back to the first primary channel.

[0147] Clause 16: The method of any one of Clauses 13-15, further comprising and adjusting a duration of the TXOP, in accordance with the allowed duration for the TXOP

[0148] Clause 17: The method of any one of Clauses 13-16, wherein the first frame comprises an initial control frame (ICF).

[0149] Clause 18: The method of any one of Clauses 13-17, further comprising and calculating the allowed duration based on at least one of: a duration of an overlapping BSS transmission

[0150] Clause 19: The method of any one of Clauses 13-18, wherein: the TXOP comprises a multi-user (MU) TXOP; and the allowed duration is based on at least one of the requested duration, a short interframe space (SIFS) associated with the second wireless node, or a time associated with transmission of the indication.

[0151] Clause 20: The method of any one of Clauses 13-19, wherein the first wireless node comprises an access point (AP) device.

[0152] Clause 21 : The method of any one of Clauses 13-20, wherein the first wireless node comprises a non-access point (AP) STA device.

[0153] Clause 22: The method of any one of Clauses 13-21, wherein the first frame comprises a trigger frame that includes at least one of an uplink length field, an allocation duration field, a duration field, or a subfield that indicates the requested duration.

[0154] Clause 23: The method of any one of Clauses 13-22, wherein the allowed duration is indicated in at least one of: an uplink length field, an allocation duration field, a duration field, or a subfield of a second frame obtained in response to the first frame.

[0155] Clause 24: An apparatus, comprising: at least one memory comprising executable instructions; and at least one processor configured to execute the executable instructions and cause the apparatus to perform a method in accordance with any one of Clauses 1-23.

[0156] Clause 25: An apparatus, comprising means for performing a method in accordance with any one of Clauses 1-23.

[0157] Clause 26: A non-transitory computer-readable medium comprising executable instructions that, when executed by at least one processor of an apparatus, cause the apparatus to perform a method in accordance with any one of Clauses 1-23.

[0158] Clause 27: A computer program product embodied on a computer-readable storage medium comprising code for performing a method in accordance with any one of Clauses 1-23.

[0159] Clause 28: A wireless node, comprising: at least one transceiver; at least one memory comprising executable instructions; and at least one processor configured to execute the executable instructions and cause the wireless node to perform a method in accordance with any one of Clauses 1-12, wherein the at least one transceiver is configured to transmit the first frame.

[0160] Clause 29: A wireless node, comprising: at least one transceiver; at least one memory comprising executable instructions; and at least one processor configured to execute the executable instructions and cause the wireless node to perform a method in accordance with any one of Clauses 13-23, wherein the at least one transceiver is configured to transmit the first frame.ADDITIONAL CONSIDERATIONS

[0161] As used herein, the term “determine” or “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, estimating, investigating, looking up (such as via looking up in a table, a database, or another data structure), inferring, ascertaining, or measuring, among other possibilities. Also, “determining” can include receiving (such as receiving information), accessing (such as accessing data stored in memory) or transmitting (such as transmitting information), among other possibilities. Additionally, “determining” can include resolving, selecting, obtaining, choosing, establishing and other such similar actions.

[0162] As used herein, a phrase referring to “at least one of’ or “one or more 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. As used herein, “or” is intended to be interpreted in the inclusive sense, unless otherwise explicitly indicated. For example, “a or b” may include a only, b only, or a combination of a and b. Furthermore, as used herein, a phrase referring to “a” or “an” element refers to one or more of such elements acting individually or collectively to perform the recited function(s). Additionally, a “set” refers to one or more items, and a “subset” refers to less than a whole set, but non-empty.

[0163] As used herein, “a processor,” “at least one processor” or “one or more processors” generally refers to a single processor configured to perform one or multiple operations or multiple processors configured to collectively perform one or more operations. In the case of multiple processors, performance the one or more operations could be divided amongst different processors, though one processor may perform multiple operations, and multiple processors could collectively perform a single operation. Similarly, “a memory,” “at least one memory” or “one or more memories” generally refers to a single memory configured to store data and / or instructions, multiple memories configured to collectively store data and / or instructions.

[0164] Means for switching, means for obtaining, means for outputting, means for communicating, means for adjusting, means for calculating, means for initiating, and / or means for indicating may comprise one or more processors, such as one or more of the processors described above with reference to Figure 12.

[0165] As used herein, “based on” is intended to be interpreted in the inclusive sense, unless otherwise explicitly indicated. For example, “based on” may be used interchangeably with “based at least in part on,” “associated with,” “in association with,” or “in accordance with” unless otherwise explicitly indicated. Specifically, unless a phrase refers to “based on only ‘a,’” or the equivalent in context, whatever it is that is “based on ‘a,’” or “based at least in part on ‘a,’” may be based on “a” alone or based on a combination of “a” and one or more other factors, conditions, or information.

[0166] The various illustrative components, logic, logical blocks, modules, circuits, operations, and algorithm processes described in connection with the examples disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware, or software, including the structures disclosed in this specification and the structural equivalents thereof. The interchangeability of hardware, firmware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system.

[0167] Various modifications to the examples described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other examples without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the examplesshown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

[0168] Additionally, various features that are described in this specification in the context of separate examples 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 examples separately or in any suitable subcombination. As such, although features may be described above as acting in particular 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.

[0169] 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 or more example processes in the form of a flowchart or 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 some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the examples described above should not be understood as requiring such separation in all examples, 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.

Claims

CLAIMS1. An apparatus for wireless communication, comprising: at least one memory comprising computer-executable instructions; and one or more processors configured to execute the computer-executable instructions and cause the apparatus to: switch, at a first wireless node, from communicating via a first primary channel to communicating via a second primary channel, after a detection of an overlapping basic service set (BSS); output, for transmission on the second primary channel, a first frame indicating a requested duration for a transmission opportunity (TXOP) associated with the second primary channel; obtain, after outputting the first frame, an indication of an allowed duration for the TXOP; and communicate with at least a second wireless node in accordance with the allowed duration for the TXOP.

2. The apparatus of claim 1, wherein: the first primary channel comprises a main primary channel; and the second primary channel comprises an opportunistic primary channel.

3. The apparatus of claim 1, wherein in order to communicate, the one or more processors are further configured to cause the first apparatus to: output, for transmission in accordance with the allowed duration for the TXOP, at least one physical layer protocol data unit (PPDU); and switch, after the end of the TXOP, from the second primary channel back to the first primary channel.

4. The apparatus of claim 3, wherein the one or more processors are further configured to cause the apparatus to adjust at least one of a duration of the at least one PPDU or a duration of the TXOP, in accordance with the allowed duration for the TXOP.

5. The apparatus of claim 1, wherein the first frame comprises an initial control frame (ICF).

6. The apparatus of claim 1, wherein the one or more processors are further configured to cause the apparatus to calculate the requested duration based on at least one of: a duration of an overlapping BSS transmission; or a quantity of data in a queue associated with the first wireless node.

7. The apparatus of claim 1, wherein: the TXOP comprises a multi-user (MU) TXOP; and the allowed duration is based on at least one of the requested duration, a short interframe space (SIFS) associated with the second wireless node, or a time associated with transmission of the indication.

8. The apparatus of claim 1, wherein the one or more processors are further configured to cause the apparatus to initiate, after the allowed duration ends, a second TXOP with a third wireless node.

9. The apparatus of claim 1, wherein the first frame comprises a trigger frame that includes at least one of an uplink length field, an allocation duration field, a duration field, or a subfield that indicates the requested duration.

10. The apparatus of claim 1, wherein the allowed duration is indicated in at least one of: an uplink length field, an allocation duration field, a duration field, or a subfield of a second frame obtained in response to the first frame.

11. The apparatus of claim 1, further comprising at least one transceiver configured to transmit the first frame, wherein the apparatus is configured as a wireless station or an access point (AP).

12. An apparatus for wireless communication, comprising: at least one memory comprising computer-executable instructions; andone or more processors configured to execute the computer-executable instructions and cause the apparatus to: switch, , at a second wireless node, from communicating via a first primary channel to communicating via a second primary channel, after a detection of an overlapping basic service set (BSS); obtain, on the second primary channel, a first frame indicating a requested duration for a transmission opportunity (TXOP) associated with the second primary channel; output, for transmission after obtaining the first frame, an indication of an allowed duration for the TXOP; and communicate with at least a first wireless node in accordance with the allowed duration for the TXOP.

13. The apparatus of claim 12, wherein: the first primary channel comprises a main primary channel; and the second primary channel comprises an opportunistic primary channel.

14. The apparatus of claim 12, wherein in order to communicate, the one or more processors are further configured to cause the apparatus to: obtain, in accordance with the allowed duration for the TXOP, at least one physical layer protocol data unit (PPDU); and switch, after the end of the TXOP, from the second primary channel back to the first primary channel.

15. The apparatus of claim 12, wherein the one or more processors are further configured to cause the apparatus to adjust a duration of the TXOP, in accordance with the allowed duration for the TXOP.

16. The apparatus of claim 12, wherein the first frame comprises an initial control frame (ICF).

17. The apparatus of claim 12, wherein the one or more processors are further configured to cause the apparatus to calculate the allowed duration based on at least one of:a duration of an overlapping BSS transmission.

18. The apparatus of claim 12, wherein: the TXOP comprises a multi-user (MU) TXOP; and the allowed duration is based on at least one of the requested duration, a short interframe space (SIFS) associated with the second wireless node, or a time associated with transmission of the indication.

19. The apparatus of claim 12, wherein the first frame comprises a trigger frame that includes at least one of an uplink length field, an allocation duration field, a duration field, or a subfield that indicates the requested duration.

20. The apparatus of claim 12, wherein the allowed duration is indicated in at least one of: an uplink length field, an allocation duration field, a duration field, or a subfield of a second frame obtained in response to the first frame.

21. The apparatus of claim 12, further comprising at least one transceiver configured to receive the first frame, wherein the apparatus is configured as a wireless station or an access point (AP).

22. A method for wireless communication at a first wireless node, comprising: switching from communicating via a first primary channel to communicating via a second primary channel, based on detection of an overlapping basic service set (BSS); outputting, for transmission on the second primary channel, a first frame indicating a requested duration for a transmission opportunity (TXOP) associated with the second primary channel; obtaining, in response to the first frame, an indication of an allowed duration for the TXOP; and communicating with at least a second wireless node in accordance with the allowed duration for the TXOP.

23. A method for wireless communication at a second wireless node, comprising: switching from communicating via a first primary channel to communicating via a second primary channel, based on detection of an overlapping basic service set (BSS);obtaining, on the second primary channel, a first frame indicating a requested duration for a transmission opportunity (TXOP) associated with the second primary channel; outputting, for transmission after obtaining the first frame, an indication of an allowed duration for the TXOP; and communicating with at least a first wireless node in accordance with the allowed duration for the TXOP.

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