Error condition management in time division multiple access

Abstract

This disclosure provides methods, components, devices and systems for error condition management in time division multiple access. Some aspects more specifically relate to recovery procedures for error conditions associated with shared transmission opportunities (TXOPs) for a channel. A sharing access point (AP) may perform a recovery procedure to request control of the channel based on the absence of an expected response message from a shared AP. The expected response message may be in response to a message announcing that the sharing AP will share one or more portions of a TXOP controlled by the sharing AP or a message that allocates a portion of the TXOP to a specific shared AP. A shared AP may perform a contention process to access the channel based on the absence of an expected TXOP allocation frame after reception of scheduling announcement from a sharing AP for a TXOP.

Description

ERROR CONDITION MANAGEMENT IN TIME DIVISION MULTIPLE ACCESSCROSS REFERENCE

[0001] The present Application for Patent claims prionty to Indian Application No. 202441030561 by KALAMKAR et al., entitled ‘ERROR CONDITION MANAGEMENT IN TIME DIVISION MULTIPLE ACCESS,” filed April 16, 2024, assigned to the assignee hereof, and expressly incorporated by reference herein.TECHNICAL FIELD

[0002] This disclosure relates generally to wireless communication and, more specifically, to error condition management in time division multiple access.DESCRIPTION OF THE RELATED TECHNOLOGY

[0003] Wireless communication networks are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. Some wireless communication netw orks may be capable of supporting communication with multiple users by sharing the available system resources (such as time, frequency, or power). Further, a wireless communication network may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). among other examples. Wireless communication devices may communicate in accordance with any one or more of such wireless communication technologies, and may include wireless stations (STAs), wireless access points (APs), user equipment (UEs), network entities, or other wireless nodes.

[0004] In some WLANs, APs may participate in coordinated TDMA (C-TDMA). In C-TDMA, an AP that owns a transmission opportunity (TXOP) (referred to as a “sharing AP”) may share a portion of the TXOP time with one or more other APs (referred to as “shared APs”). A sharing AP may initiate C-TDMA by transmitting a scheduling announcement frame that indicates a C-TDMA TXOP and identifies sharedAP(s) that the sharing AP plans to provide allocations to during the TXOP. The sharing AP may transmit a TXOP allocation frame to a shared AP that indicates a portion of the TXOP that the shared AP can use. The shared AP may transmit a response message to the TXOP allocation frame confirming that the shared AP will use the indicated portion of the TXOP.SUMMARY

[0005] 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.

[0006] One innovative aspect of the subject matter described in this disclosure can be implemented in a method for wireless communications by an apparatus. The method may include outputting a message associated with assignment of a portion of a transmission opportunity (TXOP) associated with a channel, and perform, based on an absence of a response message being obtained within a timeout duration associated with the message, a recovery procedure to request control of the channel during the portion of the TXOP.

[0007] Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communications. The apparatus may include a processing system that includes processor circuitry and memory circuitry that stores code. The processing system may be configured to cause the apparatus to output a message associated with assignment of a portion of a TXOP associated with a channel, and perform, based on an absence of a response message being obtained within a timeout duration associated with the message, a recovery procedure to request control of the channel during the portion of the TXOP.

[0008] Another innovative aspect of the subject matter described in this disclosure can be implemented in another apparatus for wireless communications. The apparatus may include means for outputting a message associated with assignment of a portion of a TXOP associated with a channel, and means for performing, based on an absence of a response message being obtained within a timeout duration associated with the message, a recovery procedure to request control of the channel during the portion of the TXOP.

[0009] Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium storing code for wireless communications. The code may include instructions executable by one or more processors to output a message associated with assignment of a portion of a TXOP associated with a channel and perform, based on an absence of a response message being obtained within a timeout duration associated with the message, a recovery procedure to request control of the channel during the portion of the TXOP.

[0010] Some examples of the method, apparatus, and non-transitory computer- readable medium described herein may further include operations, features, means, or instructions for outputting, prior to outputting the message, an announcement message that indicates that the apparatus intends to share one or more portions of the TXOP, where the message indicates an assignment of the portion of the TXOP.

[0011] Some examples of the method, apparatus, and non-transitory computer- readable medium described herein may further include operations, features, means, or instructions for outputting or obtaining, during the portion of the TXOP and after outputting the second message, a data communication.

[0012] In some examples of the method, apparatus, and non-transitory computer- readable medium described herein, the timeout duration starts after or when the message has been or is output.

[0013] Some examples of the method, apparatus, and non-transitory computer- readable medium described herein may further include operations, features, means, or instructions for outputting or obtaining, during the TXOP and prior to outputting the message, a data communication.

[0014] Some examples of the method, apparatus, and non-transitory computer- readable medium described herein may further include operations, features, means, or instructions for outputting, via the message, an indication of an assignment of a second portion of the TXOP for the channel, obtaining a second message that indicates a time within the second portion that control of the channel will return to the apparatus, and outputting or obtaining, during the portion of the TXOP and based on the second message, a data communication.

[0015] Another innovative aspect of the subject matter described in this disclosure can be implemented in a method for wireless communications by an apparatus. The method may include obtaining a first message that indicates sharing of one or more portions of a TXOP associated with a channel and performing a contention procedure for the channel during the TXOP based on an absence of a second message being obtained within a timeout duration associated with the first message, the second message being associated with assignment of a portion of the TXOP to the apparatus.

[0016] Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communications. The apparatus may include a processing system that includes processor circuitry and memory circuitry that stores code. The process system may be configured to cause the apparatus to obtain a first message that indicates sharing of one or more portions of a TXOP associated with a channel and perform a contention procedure for the channel during the TXOP based on an absence of a second message being obtained within a timeout duration associated with the first message, the second message being associated with assignment of a portion of the TXOP to the apparatus.

[0017] Another innovative aspect of the subject matter described in this disclosure can be implemented in another apparatus for wireless communications. The apparatus may include means for obtaining a first message that indicates sharing of one or more portions of a TXOP associated with a channel and means for performing a contention procedure for the channel during the TXOP based on an absence of a second message being obtained within a timeout duration associated with the first message, the second message being associated with assignment of a portion of the TXOP to the apparatus.

[0018] Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by one or more processors to obtain a first message that indicates sharing of one or more portions of a TXOP associated with a channel and perform a contention procedure for the channel during the TXOP based on an absence of a second message being obtained within a timeout duration associated with the first message, the second message being associated with assignment of a portion of the TXOP to the apparatus.

[0019] Some examples of the method, apparatus, and non-transitory computer- readable medium described herein may further include operations, features, means, or instructions for outputting or obtaining, during the TXOP and after performance of the contention procedure, a data communication.

[0020] In some examples of the method, apparatus, and non-transitory computer- readable medium described herein, the timeout duration may be based on an expected time for obtaining of the second message.

[0021] Some examples of the method, apparatus, and non-transitory computer- readable medium described herein may further include operations, features, means, or instructions for outputting a response message to the first message, where the expected time for obtaining the second message may be based on the response message.

[0022] Some examples of the method, apparatus, and non-transitory computer- readable medium described herein may further include operations, features, means, or instructions for obtaining an indication of a response period for outputing the response message, where the response message may be output in accordance with the response period.

[0023] Some examples of the method, apparatus, and non-transitory computer- readable medium described herein may further include operations, features, means, or instructions for obtaining an indication of a resource unit for output of the response message, where the response message may be output using the resource unit.

[0024] In some examples of the method, apparatus, and non-transitory computer- readable medium described herein, the first message indicates the expected time for obtaining of the second message.

[0025] Details of one or more implementations of the subject mater 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 draw n to scale.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 shows a pictorial diagram of an example wireless communication network.

[0027] Figure 2 shows an example protocol data unit (PDU) usable for communications between a wireless access point (AP) and one or more wireless stations (STAs).

[0028] Figure 3 shows an example physical layer (PHY) protocol data unit (PPDU) usable for communications between a wireless AP and one or more wireless STAs.

[0029] Figure 4 shows a hierarchical format of an example PPDU usable for communications between a wireless AP and one or more wireless STAs.

[0030] Figure 5 shows an example of a signaling diagram that supports error condition management in time division multiple access (TDMA).

[0031] Figure 6 shows an example of a timing diagram that supports error condition management in TDMA.

[0032] Figure 7 shows an example of a timing diagram that supports error condition management in TDMA.

[0033] Figure 8 shows an example of a timing diagram that supports error condition management in TDMA.

[0034] Figure 9 shows an example of a timing diagram that supports error condition management in TDMA.

[0035] Figure 10 shows an example of a process flow that supports error condition management in TDMA.

[0036] Figure 11 shows an example of a process flow that supports error condition management in TDMA.

[0037] Figure 12 shows a block diagram of an example wireless communication device that supports error condition management in TDMA.

[0038] Figures 13 and 14 show flowcharts illustrating example processes performable by or at an AP that supports error condition management in TDMA.

[0039] Like reference numbers and designations in the various drawings indicate like elements.DETAILED DESCRIPTION

[0040] 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, 5G (New Radio (NR)) or 6G standards promulgated by the 3rd Generation Partnership Project (3GPP), among others. The described examples can be implemented in any suitable device, component, 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), a nonterrestrial network (NTN). or an internet of things (1OT) network.

[0041] Various aspects relate generally to recovery procedures for error conditions associated with shared transmission opportunities (TXOPs) for a channel. Some aspects more specifically relate to performance of a recovery' procedure for control of a channel by a sharing access point (AP) based on the absence of an expected response message from a shared AP. A wireless communication system may allow an AP that owns orcontrols a TXOP (e.g., a sharing AP) to share a portion of the TXOP with one or more other APs (e.g., shared APs). In some examples, the expected response message may be a message responding to a message announcing that the sharing AP will share one or more portions of a TXOP controlled by the sharing AP (for example, a scheduling announcement frame or message). In some examples, the expected response message may be a message responding to a message that allocates a portion of the TXOP to a specific shared AP (for example, a TXOP allocation frame or message). The sharing AP may be an AP that controls the TXOP. and a shared AP may be an AP that receives an allocation of a portion of the TXOP from the sharing AP. Some aspects may relate to timeout durations for which the sharing AP may wait for an expected response message before performing the recovery procedure. Some aspects may more specifically relate to performance of a contention procedure by a shared AP to access the channel based on the absence of an expected TXOP allocation frame after reception of a scheduling announcement from a sharing AP for a TXOP. Some aspects may relate to timeout durations for which the shared AP may wait for an expected TXOP allocation frame before performing the contention procedure.

[0042] 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, by performing a recovery procedure based on the absence of an expected response message from a shared AP, the described techniques can be used to allow a sharing AP to maintain or regain control of a TXOP when a sharing AP does not use or does not intend to use an allocated portion of the TXOP. By waiting for configured timeout durations prior to performing the recovery procedure, the sharing AP may allow sufficient time for the shared AP to respond to a message from the sharing AP without losing control of the TXOP. Further, by performing a contention procedure based on the absence of an expected TXOP allocation frame after reception of scheduling announcement from a sharing AP for a TXOP, the described techniques may be used to enable a shared AP to more quickly access the channel to communicate with stations (STAs) associated with the shared AP. Accordingly, latency of communications involving the shared AP may be reduced. Further, efficiency of the channel may be increased as a shared AP may contend for unused portions of a TXOP.

[0043] 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, 802.11bc, 802. 1 Ibd, 802. 1 Ibe, 802. 1 Ibf. and 802. 1 Ibn). 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. 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 personal area networks, such as a network implementing Bluetooth or other wireless technologies, to provide greater or enhanced network coverage or to provide or enable other capabilities, functionality, applications or services.

[0044] The wireless communication network 100 may include numerous wireless communication devices including at least one wireless AP 102 and any number of wireless 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, atri-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).

[0045] 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 entry7and start (PKES) systems), Internet of Things (loT) devices, and vehicles, among other examples.

[0046] 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 re-associate 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 networksto various STAs 104 in the wireless communication network 100 via respective communication links 106.

[0047] 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 generates and 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.

[0048] As a result of the increasing ubiquity of wireless networks, a STA 104 may have the opportunity7to 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.

[0049] In some examples, 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 examples, ad hocnetworks 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 wireless 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 fdled 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.

[0050] 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 maysupport additional ULL applications such as cloud-based applications (such as VR cloud gaming) that have ULL and high throughput requirements.

[0051] 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).

[0052] Each PPDU is a composite structure that includes a PEIY 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.

[0053] The APs 102 and STAs 104 in the wireless communication network 100 may 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, 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).

[0054] Each of the frequency bands may include multiple sub-bands and frequency channels (also referred to as subchannels). The terms “channel” and “subchannel” may be used interchangeably herein, as each may refer to a portion of frequency spectrum within a frequency band (for example, a 20 MHz, 40 MHz, 80 MHz, or 160 MHz portion of frequency spectrum) via which communication between two or more wireless communication devices can occur. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac, 802.11ax, 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 isdivided 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.

[0055] An AP 102 may determine or select an operating or operational bandwidth for the STAs 104 in its BSS and select a range of channels within a band to provide that operating bandwidth. For example, the AP 102 may select sixteen 20 MHz channels that collectively span an operating bandwidth of 320 MHz. Within the operating bandwidth, the AP 102 may typically select a single primary 20 MHz channel on which the AP 102 and the STAs 104 in its BSS monitor for contention-based access schemes. In some examples, the AP 102 or the STAs 104 may be capable of monitoring only a single primary 20 MHz channel for packet detection (for example, for detecting preambles of PPDUs). Conventionally, any transmission by an AP 102 or a STA 104 within a BSS must involve transmission on the primary 20 MHz channel. As such, in conventional systems, the transmitting device must contend on and win a TXOP on the primary channel to transmit anything at all. However, some APs 102 and STAs 104 supporting ultra-high reliability (UHR) communications or communication according to the IEEE 802. 1 Ibn standard amendment can be configured to operate, monitor, contend and communicate using multiple primary 20 MHz channels. Such monitoring of multiple primary 20 MHz channels may be sequential such that responsive to determining, ascertaining or detecting that a first primary 20 MHz channel is not available, a wireless communication device may switch to monitoring and contending using a second primary 20 MHz channel. Additionally, or alternatively, a wireless communication device may be configured to monitor multiple primary720 MHz channels in parallel. In some examples, a first primary 20 MHz channel may be referred to as a main primary (M-Primary) channel and one or more additional, second primary' channels may each be referred to as an opportunistic primary' (O-Primary) channel. For example, if a wireless communication device measures, identifies, ascertains, detects, or otherwise determines that the M-Primary channel is busy or occupied (such as due to an overlapping BSS (OBSS) transmission), the wireless communication device may switch to monitoring and contending on an O-Primarychannel. In some examples, the M-Primary channel may be used for beaconing and serving legacy client devices and an O-Primary channel may be specifically used by non-legacy (for example, UHR- or IEEE 802.11bn-compatible) devices for opportunistic access to spectrum that may be otherwise under-utilized.

[0056] Figure 2 shows an example protocol data unit (PDU) 200 usable for wireless communication between a wireless AP and one or more wireless STAs. For example, the AP and STAs may be examples of the AP 102 and the STAs 104 described with reference to Figure 1. The PDU 200 can be configured as a PPDU. As shown, the PDU 200 includes a PHY preamble 202 and a PHY payload 204. For example, the preamble 202 may include a legacy portion that itself includes a legacy short training field (L- STF) 206, which may consist of two symbols, a legacy long training field (L-LTF) 208, which may consist of two symbols, and a legacy signal field (L-SIG) 210, which may consist of two symbols. The legacy portion of the preamble 202 may be configured according to the IEEE 802. 1 la wireless communication protocol standard. The preamble 202 also may include a non-legacy portion including one or more non-legacy fields 212, for example, conforming to one or more of the IEEE 802. 11 family of wireless communication protocol standards.

[0057] The L-STF 206 generally enables a receiving device (such as an AP 102 or a STA 104) to perform coarse timing and frequency tracking and automatic gain control (AGC). The L-LTF 208 generally enables the receiving device to perform fine timing and frequency tracking and also to perform an initial estimate of the wireless channel. The L-SIG 210 generally enables the receiving device to determine (for example, obtain, select, identify, detect, ascertain, calculate, or compute) a duration of the PDU and to use the determined duration to avoid transmitting on top of the PDU. The legacy portion of the preamble, including the L-STF 206, the L-LTF 208 and the L-SIG 210, may be modulated according to a binary phase shift keying (BPSK) modulation scheme. The pay load 204 may be modulated according to a BPSK modulation scheme, a quadrature BPSK (Q-BPSK) modulation scheme, a quadrature amplitude modulation (QAM) modulation scheme, or another appropriate modulation scheme. The payload 204 may include a PSDU including a data field (DATA) 214 that, in turn, may cany7higher layer data, for example, in the form of MAC protocol data units (MPDUs) or an aggregated MPDU (A-MPDU).

[0058] Figure 3 shows an example physical layer (PHY) protocol data unit (PPDU) 350 usable for communications between a wireless AP and one or more wireless STAs. For example, the AP and STAs may be examples of the AP 102 and the STAs 104 described with reference to Figure 1. As shown, the PPDU 350 includes a PHY preamble, that includes a legacy portion 352 and a non-legacy portion 354, and a payload 356 that includes a data field 374. The legacy portion 352 of the preamble includes an L-STF 358, an L-LTF 360, and an L-SIG 362. The non-legacy portion 354 of the preamble includes a repetition of L-SIG (RL-SIG) 364 and multiple wireless communication protocol version-dependent signal fields after RL-SIG 364. For example, the non-legacy portion 354 may include a universal signal field 366 (referred to herein as “U-SIG 366”) and an EHT signal field 368 (referred to herein as “EHT-SIG 368”). The presence of RL-SIG 364 and U-SIG 366 may indicate to EHT- or later version-compliant STAs 104 that the PPDU 350 is an EHT PPDU or a PPDU conforming to any later (post-EHT) version of a new wireless communication protocol conforming to a future IEEE 802. 11 wireless communication protocol standard. One or both of U-SIG 366 and EHT-SIG 368 may be structured as, and carry versiondependent information for. other wireless communication protocol versions associated with amendments to the IEEE family of standards beyond EHT. For example, U-SIG 366 may be used by a receiving device (such as an AP 102 or a STA 104) to interpret bits in one or more of EHT-SIG 368 or the data field 374. Like L-STF 358, L-LTF 360, and L-SIG 362, the information in U-SIG 366 and EHT-SIG 368 may be duplicated and transmitted in each of the component 20 MHz channels in instances involving the use of a bonded channel.

[0059] The non-legacy portion 354 further includes an additional short training field 370 (referred to herein as “EHT-STF 370,” although it may be structured as, and carry version-dependent information for, other wireless communication protocol versions beyond EHT) and one or more additional long training fields 372 (referred to herein as “EHT-LTFs 372,” although they may be structured as, and carry version-dependent information for, other wireless communication protocol versions beyond EHT). EHT- STF 370 may be used for timing and frequency tracking and AGC, and EHT-LTF 372 may be used for more refined channel estimation.

[0060] EHT-SIG 368 may be used by an AP 102 to identify and inform one or multiple STAs 104 that the AP 102 has scheduled uplink (UL) or downlink (DL) resources for them. EHT-SIG 368 may be decoded by each compatible STA 104 served by the AP 102. EHT-SIG 368 may generally be used by the receiving device to interpret bits in the data field 374. For example, EHT-SIG 368 may include resource unit (RU) allocation information, spatial stream configuration information, and per-user (for example, STA-specific) signaling information. Each EHT-SIG 368 may include a common field and at least one user-specific field. In the context of OFDMA. the common field can indicate RU distributions to multiple STAs 104, indicate the RU assignments in the frequency domain, indicate which RUs are allocated for MU-MIMO transmissions and which RUs correspond to OFDMA transmissions, and the number of users in allocations, among other examples. The user-specific fields are assigned to particular STAs 104 and carry STA-specific scheduling information such as userspecific MCS values and user-specific RU allocation information. Such information enables the respective STAs 104 to identify and decode corresponding RUs in the associated data field 374.

[0061] Figure 4 shows a hierarchical format of an example PPDU usable for communications between a wireless AP and one or more wireless STAs. For example, the AP and STAs may be examples of the AP 102 and the STAs 104 described with reference to Figure 1. As described, each PPDU 400 includes a PHY preamble 402 and a PSDU 404. Each PSDU 404 may represent (or “carry”) one or more MAC protocol data units (MPDUs) 416. For example, each PSDU 404 may carry an aggregated MPDU (A-MPDU) 406 that includes an aggregation of multiple A-MPDU subframes 408. Each A-MPDU subframe 408 may include an MPDU frame 410 that includes a MAC delimiter 412 and a MAC header 414 prior to the accompanying MPDU 416, which includes the data portion (“payload” or “frame body”) of the MPDU frame 410. Each MPDU frame 410 also may include a frame check sequence (FCS) field 418 for error detection (for example, the FCS field 418 may include a cyclic redundancy check (CRC)) and padding bits 420. The MPDU 416 may cany7one or more MAC service data units (MSDUs) 430. For example, the MPDU 416 may cany7an aggregated MSDU (A-MSDU) 422 including multiple A-MSDU subframes 424. Each A-MSDU subframe 424 may be associated with an MSDU frame 426 and may contain a correspondingMSDU 430 preceded by a subframe header 428 and, in some examples, followed by padding bits 432.

[0062] Referring back to the MPDU frame 410, the MAC delimiter 412 may serve as a marker of the start of the associated MPDU 416 and indicate the length of the associated MPDU 416. The MAC header 414 may include multiple fields containing information that defines or indicates characteristics or attributes of data encapsulated within the frame body. The MAC header 414 includes a duration field indicating a duration extending from the end of the PPDU until at least the end of an acknowledgement (ACK) or Block ACK (BA) of the PPDU that is to be transmitted by the receiving wireless communication device. The use of the duration field serves to reserve the wireless medium for the indicated duration and enables the receiving device to establish its network allocation vector (NAV). The MAC header 414 also includes one or more fields indicating addresses for the data encapsulated within the frame body. For example, the MAC header 414 may include a combination of a source address, a transmitter address, a receiver address or a destination address. The MAC header 414 may further include a frame control field containing control information. The frame control field may specify a frame type, for example, a data frame, a control frame, or a management frame.

[0063] In some wireless communication systems, wireless communication between an AP 102 and an associated STA 104 can be secured. For example, either an AP 102 or a STA 104 may establish a security key for securing wireless communication between itself and the other device and may encrypt the contents of the data and management frames using the security key. In some examples, the control frame and fields within the MAC header of the data or management frames, or both, also may be secured either via encryption or via an integrity check (for example, by generating a message integrity check (MIC) for one or more relevant fields.

[0064] 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 contend for access to the wireless medium. The DCF is implemented through the use of time intervals (includingthe slot time (or ‘'slot interval”) and the inter-frame space (TFS). 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.

[0065] 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 -lev el) 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 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.

[0066] 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 device performs the physical carrier sensing. If the channel remains idle for the appropriate IFS, the w ireless 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 wirelesscommunication device becomes the holder (or “owner”) of a transmit opportunity (TXOP) (also referred to as a transmission opportunity) 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.

[0067] Each time the wireless communication device generates a new PPDU for transmission in anew 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.

[0068] 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 a WLAN in accordance with an enhanced distributed channel access (EDCA) 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 priority data and assigning higher RBOs to lower priority data). Although EDCA 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.

[0069] Some APs and STAs (for example, the AP 102 and the STAs 104 described with reference to Figure 1) may implement spatial reuse techniques. For example, APs 102 and STAs 104 configured for communications using the protocols defined in the IEEE 802. 11 ax or 802.1 Ibe standard amendments may be configured with a BSS color.APs 102 associated with different BSSs may be associated with different BSS colors. A BSS color is a numerical identifier of an AP 102’s respective BSS (such as a 6 bit field carried by the SIG field). Each STA 104 may learn its own BSS color upon association with the respective AP 102. BSS color information is communicated at both the PHY and MAC sublayers. If an AP 102 or a STA 104 detects, obtains, selects, or identifies, a wireless packet from another wireless communication device while contending for access, the AP 102 or the STA 104 may apply different contention parameters in accordance with whether the wireless packet is transmitted by, or transmitted to, another wireless communication device (such another AP 102 or STA 104) within its BSS or from a wireless communication device from an overlapping BSS (OBSS), as determined, identified, ascertained, or calculated by a BSS color indication in a preamble of the wireless packet. For example, if the BSS color associated with the wireless packet is the same as the BSS color of the AP 102 or STA 104, the AP 102 or STA 104 may use a first RSSI detection threshold when performing a CCA on the wireless channel. However, if the BSS color associated with the wireless packet is different than the BSS color of the AP 102 or STA 104, the AP 102 or STA 104 may use a second RSSI detection threshold in lieu of using the first RSSI detection threshold when performing the CCA on the wireless channel, the second RSSI detection threshold being greater than the first RSSI detection threshold. In this way, the criteria for winning contention are relaxed when interfering transmissions are associated with an OBSS.

[0070] Some APs and STAs (for example, the AP 102 and the STAs 104 described with reference to Figure 1) may implement techniques for spatial reuse that involve participation in a coordinated communication scheme. According to such techniques, an AP 102 may contend for access to a wireless medium to obtain control of the medium for a TXOP. The AP that wins the contention (hereinafter also referred to as a “sharing AP”) may select one or more other APs (hereinafter also referred to as “shared APs”) to share resources of the TXOP. The sharing and shared APs may be located in proximity to one another such that at least some of their wireless coverage areas at least partially overlap. Some examples may specifically involve coordinated AP TDMA or OFDMA techniques for sharing the time or frequency resources of a TXOP. To share its time or frequency resources, the sharing AP may partition the TXOP into multipletime segments or frequency segments each including respective time or frequency resources representing a portion of the TXOP. The sharing AP may allocate the time or frequency segments to itself or to one or more of the shared APs. For example, each shared AP may utilize a partial TXOP assigned by the sharing AP for its uplink or downlink communications with its associated STAs.

[0071] In some examples of such TDMA techniques, each portion of a plurality of portions of the TXOP includes a set of time resources that do not overlap with any time resources of any other portion of the plurality of portions of the TXOP. In such examples, the scheduling information may include an indication of time resources, of multiple time resources of the TXOP, associated with each portion of the TXOP. For example, the scheduling information may include an indication of a time segment of the TXOP such as an indication of one or more slots or sets of symbol periods associated with each portion of the TXOP such as for multi-user TDMA.

[0072] In some examples of OFDMA techniques, each portion of the plurality of portions of the TXOP includes a set of frequency resources that do not overlap with any frequency resources of any other portion of the plurality of portions. In such examples, the scheduling information may include an indication of frequency resources, of multiple frequency resources of the TXOP, associated with each portion of the TXOP. For example, the scheduling information may include an indication of a bandwidth portion of the wireless channel such as an indication of one or more subchannels or RUs associated with each portion of the TXOP such as for multi-user OFDMA.

[0073] In this manner, the sharing AP's acquisition of the TXOP enables communication between one or more additional shared APs and their respective BSSs, subject to appropriate power control and link adaptation. For example, the sharing AP may limit the transmit powers of the selected shared APs such that interference from the selected APs does not prevent STAs associated with the TXOP owner from successfully decoding packets transmitted by the sharing AP. Such techniques may be used to reduce latency because the other APs may not need to wait to win contention for a TXOP to be able to transmit and receive data according to conventional CSMA / CA or enhanced distributed channel access (EDCA) techniques. Additionally, by enabling a group of APs 102 associated with different BSSs to participate in a coordinated AP transmission session, during which the group of APs may share at least a portion of asingle TXOP obtained by any one of the participating APs, such techniques may increase throughput across the BSSs associated with the participating APs and also may achieve improvements in throughput fairness. Furthermore, with appropriate selection of the shared APs and the scheduling of their respective time or frequency resources, medium utilization may be maximized or otherwise increased while packet loss resulting from OBSS interference is minimized or otherwise reduced. Various implementations may achieve these and other advantages without requiring that the sharing AP or the shared APs be aware of the STAs 104 associated with other BSSs, without requiring a preassigned or dedicated master AP or preassigned groups of APs, and without requiring backhaul coordination between the APs participating in the TXOP.

[0074] In some examples in which the signal strengths or levels of interference associated with the selected APs are relatively low (such as less than a given value), or when the decoding error rates of the selected APs are relatively low (such as less than a threshold), the start times of the communications among the different BSSs may be synchronous. Conversely, when the signal strengths or levels of interference associated with the selected APs are relatively high (such as greater than the given value), or when the decoding error rates of the selected APs are relatively high (such as greater than the threshold), the start times may be offset from one another by a time period associated with decoding the preamble of a wireless packet and determining, from the decoded preamble, whether the wireless packet is an intra-BSS packet or is an OBSS packet. For example, the time period between the transmission of an intra-BSS packet and the transmission of an OBSS packet may allow a respective AP (or its associated STAs) to decode the preamble of the wireless packet and obtain the BSS color value carried in the wireless packet to determine whether the wireless packet is an intra-BSS packet or an OBSS packet. In this manner, each of the participating APs and their associated STAs may be able to receive and decode intra-BSS packets in the presence of OBSS interference.

[0075] In some examples, the sharing AP may perform polling of a set of unmanaged or non-co-managed APs that support coordinated reuse to identify candidates for future spatial reuse opportunities. For example, the sharing AP may transmit one or more spatial reuse poll frames as part of determining one or more spatial reuse criteriaand selecting one or more other APs to be shared APs. According to the polling, the sharing AP may receive responses from one or more of the polled APs. In some specific examples, the sharing AP may transmit a coordinated AP TXOP indication (CTI) frame to other APs that indicates time and frequency of resources of the TXOP that can be shared. The sharing AP may select one or more candidate APs upon receiving a coordinated AP TXOP request (CaTR) frame from a respective candidate AP that indicates a desire by the respective AP to participate in the TXOP. The poll responses or CaTR frames may include a power indication, for example, a receive (RX) power or RSS1 measured by the respective AP. In some other examples, the sharing AP may directly measure potential interference of a service supported (such as UL transmission) at one or more APs, and select the shared APs based on the measured potential interference. The sharing AP generally selects the APs to participate in coordinated spatial reuse such that it still protects its own transmissions (which may be referred to as primary transmissions) to and from the STAs in its BSS. The selected APs may be allocated resources during the TXOP as described above.

[0076] In some implementations, the AP 102 and STAs 104 can support various multi-user communications; that is, concurrent transmissions from one device to each of multiple devices (for example, multiple simultaneous downlink communications from an AP 102 to corresponding STAs 104), or concurrent transmissions from multiple devices to a single device (for example, multiple simultaneous uplink transmissions from corresponding STAs 104 to an AP 102). As an example, in addition to MU- MIMO, the AP 102 and STAs 104 may support OFDMA. OFDMA is in some aspects a multi-user version of OFDM.

[0077] In OFDMA schemes, the available frequency spectrum of the wireless channel may be divided into multiple RUs each including multiple frequency subcarriers (also referred to as “tones’"). Different RUs may be allocated or assigned by an AP 102 to different STAs 104 at particular times. The sizes and distributions of the RUs may be referred to as an RU allocation. In some examples, RUs may be allocated in 2 MHz intervals, and as such, the smallest RU may include 26 tones consisting of 24 data tones and 2 pilot tones. Consequently, in a 20 MHz channel, up to 9 RUs (such as 2 MHz, 26-tone RUs) may be allocated (because some tones are reserved for other purposes). Similarly, in a 160 MHz channel, up to 74 RUs may be allocated. Othertone RUs also may be allocated, such as 52 tone, 106 tone, 242 tone, 484 tone and 996 tone RUs. Adjacent RUs may be separated by a null subcarrier (such as a DC subcarrier), for example, to reduce interference between adjacent RUs, to reduce receiver DC offset, and to avoid transmit center frequency leakage.

[0078] For UL MU transmissions, an AP 102 can transmit a trigger frame to initiate and synchronize an UL OFDMA or UL MU-MIMO transmission from multiple STAs 104 to the AP 102. Such trigger frames may thus enable multiple STAs 104 to send UL traffic to the AP 102 concurrently in time. A trigger frame may address one or more STAs 104 through respective association identifiers (AIDs), and may assign each AID (and thus each STA 104) one or more RUs that can be used to send UL traffic to the AP 102. The AP also may designate one or more random access (RA) RUs that unscheduled STAs 104 may contend for.

[0079] In some wireless communications systems, an AP 102 may allocate or assign multiple RUs to a single STA104 in an OFDMA transmission (hereinafter also referred to as “multi-RU aggregation"). Multi-RU aggregation, which facilitates puncturing and scheduling flexibility’, may ultimately reduce latency. As increasing bandwidth is supported by emerging standards (such as the IEEE 802.11 be standard amendment supporting 320 MHz and the IEEE 802. 1 Ibn standard amendment supporting 480 MHz and 640 MHz), various multiple RU (multi-RU) combinations may exist. Values indicating the various multi-RU combinations may be provided by a suitable standard specification (such as one or more of the IEEE 802. 11 family of wireless communication protocol standards including the 802. 1 Ibe standard amendment and the 802. 1 Ibn standard amendment).

[0080] As Wi-Fi is not the only technology operating in the 6 GHz band, the use of multiple RUs in conjunction with channel puncturing may enable the use of large bandwidths such that high throughput is possible while avoiding transmitting on frequencies that are locally unauthorized due to incumbent operation. Puncturing may be used in conjunction with multi-RU transmissions to enable wide channels to be established using non-contiguous spectrum blocks. In such examples, the portion of the bandwidth between two RUs allocated to a particular STA 104 may be punctured. Accordingly, spectrum efficiency and flexibility may be increased.

[0081] As described previously, STA-specific RU allocation information may be included in a signaling field (such as the EHT-SIG field for an EHT PPDU) of the PPDU’s preamble. Preamble puncturing may enable wider bandwidth transmissions for increased throughput and spectral efficiency in the presence of interference from incumbent technologies and other wireless communication devices. Because RUs maybe individually allocated in a MU PPDU, use of the MU PPDU format may indicate preamble puncturing for SU transmissions. While puncturing in the IEEE 802.11 ax standard amendment was limited to OFDMA transmissions, the IEEE 802. 1 Ibe standard amendment extended puncturing to SU transmissions. In some examples, the RU allocation information in the common field of EHT-SIG can be used to individually allocate RUs to the single user, thereby avoiding the punctured channels. In some other examples, U-SIG may be used to indicate SU preamble puncturing. For example, the SU preamble puncturing may be indicated by a value of the EHT-SIG compression field in U-SIG.

[0082] In some environments, locations, or conditions, a regulatory body may impose a power spectral density (PSD) limit for one or more communication channels or for an entire band (for example, the 6 GHz band). A PSD is a measure of transmit power as a function of a unit bandwidth (such as per 1 MHz). The total transmit power of a transmission is consequently the product of the PSD and the total bandwidth by which the transmission is sent. Unlike the 2.4 GHz and 5 GHz bands, the United States Federal Communications Commission (FCC) has established PSD limits for low power devices when operating in the 6 GHz band. The FCC has defined three power classes for operation in the 6 GHz band: standard power, low power indoor, and very low power. Some APs 102 and ST As 104 that operate in the 6 GHz band may conform to the low power indoor (LPI) power class, which limits the transmit power of APs 102 and STAs 104 to 5 decibel-milliwatts per megahertz (dBm / MHz) and - 1 dBm / MHz, respectively. In other words, transmit power in the 6 GHz band is PSD-limited on a per-MHz basis.

[0083] Such PSD limits can undesirably reduce transmission ranges, reduce packet detection capabilities, and reduce channel estimation capabilities of APs 102 and STAs 104. In some examples in which transmissions are subject to a PSD limit, the AP 102 or the STAs 104 of a wireless communication network 100 may transmit over a greatertransmission bandwidth to allow for an increase in the total transmit power, which may increase an SNR and extend coverage of the wireless communication devices. For example, to overcome or extend the PSD limit and improve SNR for low power devices operating in PSD-limited bands, 802.1 Ibe introduced a duplicate (DUP) mode for a transmission, by which data in a payload portion of a PPDU is modulated for transmission over a “base” frequency sub-band, such as a first RU of an OFDMA transmission, and copied over (for example, duplicated) to another frequency sub-band, such as a second RU of the OFDMA transmission. In DUP mode, two copies of the data are to be transmitted, and. for each of the duplicate RUs. using dual carrier modulation (DCM), which also has the effect of copying the data such that two copies of the data are carried by each of the duplicate RUs, so that, for example, four copies of the data are transmitted. While the data rate for transmission of each copy of the user data using the DUP mode may be the same as a data rate for a transmission using a “normal” mode, the transmit power for the transmission using the DUP mode may be essentially multiplied by the number of copies of the data being transmitted, at the expense of requiring an increased bandwidth. As such, using the DUP mode may extend range but reduce spectrum efficiency.

[0084] In some other examples in which transmissions are subject to a PSD limit, a distributed tone mapping operation may be used to increase the bandwidth via which a STA 104 transmits an uplink communication to the AP 102. As used herein, the term “distributed transmission” refers to a PPDU transmission on noncontiguous tones (or subcarriers) of a wireless channel. In contrast, the term “contiguous transmission” refers to a PPDU transmission on contiguous tones. As used herein, a logical RU represents a number of tones or subcarriers that are allocated to a given STA 104 for transmission of a PPDU. As used herein, the term “regular RU” (or rRU) refers to any RU or MRU tone plan that is not distributed, such as a configuration supported by 802. 1 Ibe or earlier versions of the IEEE 802. 11 family of wireless communication protocol standards. As used herein, the term “distributed RU” (or dRU) refers to the tones distributed across a set of noncontiguous subcarrier indices to which a logical RU is mapped. The term “distributed tone plan” refers to the set of noncontiguous subcarrier indices associated with a dRU. The channel or portion of a channel within which the distributed tones are interspersed is referred to as a spreading bandwidth,which may be, for example, 40 MHz, 80 MHz or more. The use of dRUs may be limited to uplink communications because benefits to addressing PSD limits may only be present for uplink communications.

[0085] Figure 5 shows an example of a signaling diagram 500 that supports error condition management in TDMA. The signaling diagram 500 may implement or may be implemented by aspects of the wireless communication network 100. For example, the signaling diagram 500 may include an AP 502-a and an AP 502-b, which may be examples of APs 102 as described with reference to Figure 1. The signaling diagram 500 may include a STA 504-a and a STA 504-b, which may be examples of STAs 104 as described with reference to Figure 1. For example, the STA 504-a may be within a coverage area 508-a of the AP 502-a and the STA 504-b may be within a coverage area 508-b of the AP 502-b. The AP 502-a and the STA 504-a may communicate via a wireless communication link 510-a, and the AP 502-b and the STA 504-b may communicate via a wireless communication link 510-b. In some examples, the AP 502-a may communicate with the AP 502-b via a communication link 512. A wireless node may refer to a wireless communication device, such as an AP (for example, the AP 502-a) or a STA (for example, the STA 504-a) that communicates via the wireless communication network 100.

[0086] Some WLANs, such as the WLANs shown in Figure 5 may implement coordinated TDMA (C-TDMA). TDMA may allow an AP that owns or controls a TXOP (for example, the TXOP 514) to share a portion of the TXOP with one or more other APs. For example, the AP 502-a may own or control the TXOP 514. C-TDMA may improve latency and reduce contentions and / or collisions. EHT transmit status (TXS) framework may be used to facilitate C-TDMA. For example, MU request to send (RTS) (MU-RTS) frames and MU-RTS TXS frames may be used to identify shared TXOPs between APs 502.

[0087] In some examples, frame exchange to share a portion of a TXOP in C- TDMA may use framework defined by 802. 1 lax and / or 802. 1 Ibe. For example, as shown in the timing diagram 550, the AP 502-a may be the sharing AP and the AP 502-b may be the shared AP. The AP 502-a may transmit a scheduling announcement frame 520 at or near the beginning of the TXOP 514 controlled or owned by the AP 502-a. The scheduling announcement frame 520 may announce the C-TDMA scheduleto the AP 502 -b and any other shared APs 102. In some examples, the AP 502-b may transmit a response message 522 to the scheduling announcement frame 520. For example, the response message 522 to the scheduling announcement frame 520 may be a control response (CTR) message.

[0088] After the scheduling announcement frame, the AP 502-a may perform frame exchange 524 with STAs 104 served by the AP 502-a (for example, may transmit frames to or receive frames from the STA 504-a and / or other STAs 104 in the same BSS as the AP 502-a).

[0089] The AP 502-a may trigger TXOP sharing with the AP 502-b via transmission of a TXOP allocation frame 526. In some examples, the AP 502-b may transmit a response message 528 to the TXOP allocation frame 526. For example, the response message 528 to the TXOP allocation frame 526 may be a clear to send (CTS) frame if the TXOP Allocation frame is an MU-RTS TXS frame.

[0090] Based on reception of the TXOP allocation frame 526 allocating or assigning a portion of the TXOP 514 to the AP 502-b. the AP 502-b may perform frame exchange 530 with STAs 104 served by the AP 502-b (for example, may transmit frames to or receive frames from the STA 504-b and / or other STAs 104 in the same BSS as the AP 502-b). The AP 502-b may transmit a TXOP return frame 534 which may return control of the TXOP 514 to the AP 502-a for any unused sub-portion of the portion of the TXOP 514 assigned or allocated to the AP 502-b. For example, the AP 502-a may perform additional frame exchange with STAs 104 served by the AP 502-a using the returned sub-portion of the TXOP 514. As another example, the AP 502-a may allocate or assign the returned sub-portion of the TXOP 514 to another AP 102 (for example, other than the AP 502-b).

[0091] In some examples, C-TDMA may implement long NAV. In some examples, C-TDMA may implement short NAV. In some examples, the sharing AP (for example, the AP 502-a) may share a TXOP (such as the TXOP 514) with more than one shared AP.

[0092] As described herein, error conditions may occur in C-TDMA scenarios. For example, a shared AP (for example, the AP 502-b) may fail to take over a portion of a TXOP allocated or assigned to the shared AP. In such examples, the shared AP and / orthe sharing AP may identify the error and may perform appropriate actions to recover from the TXOP sharing error scenario. As another example, the sharing AP (for example, the AP 502-a) may lose control of the channel medium during the C-TDMA frame exchanges. For example, in the case where the scheduling announcement frame fails, the AP 502-a may give up control of the channel for the TXOP 514 and begin a backoff procedure. For example, the scheduling announcement frame may be an MU- RTS, and the scheduling announcement frame 520 may fail if no CTS response is received from the target shared AP in a single- AP sharing C-TDMA example. In some examples, the sharing AP (for example, the AP 502-a) may implement a polling scheme where multiple recipient APs (for example, the AP 502-b and one or more other APs 102 or STAs 104) are each assigned an RU to respond to the scheduling announcement frame 520. For example, a buffer status report poll (BSRP) may be used as a trigger frame, and RUs may be assigned to obtain the response from each entity (for example, STAs 104 served by the AP 502-a, the target shared AP 102 (for example, the AP 502-b), and a candidate shared AP 102). In such examples, as the response may be solicited from multiple entities, the chance of failure of the scheduling announcement frame may be reduced.

[0093] In some examples, when the AP 502-b returns the residual portion of the TXOP 514 to the AP 502-a (for example, via the TXOP return frame 534), the AP 502-a may fail to regain control of the channel. For example, the AP 502-a may be busy when the TXOP return indication is made. As another example, the AP 502-a may demand some processing time to take back control of the TXOP 514. During the busy time or processing time of the AP 502-a, another AP 102 or STA 104 may take control of the channel, leading to loss of control of the channel for the AP 502-a. To prevent loss of control of the channel, after the TXOP allocation frame 526, the AP 502-b may indicate to the AP 502-a (for example, in the response message 528 or during the frame exchange 530) an estimated time at which the TXOP return will be made if TXOP return is expected to occur. Accordingly, the AP 502-a may be ready to take back control of the channel at the indicated time. As an example, after a CTS response (for example, the response message 528) to the TXOP allocation frame 526, the AP 502-b may send a downlink MU PPDU to indicate the expected TXOP return time to the AP 502-a, and the AP 502-b may simultaneously communicate with a STA 104 served bythe AP 502-b. For example, such a downlink MU PPDU may have an RU intended for the AP 502-a and one or more other RUs intended for the STA(s) 104 in the BSS of the AP 502-b. In some examples, the RU intended for the AP 502-a may be identified with the STA ID set to the AID assigned to the AP 502-a by the AP 502-b. As another example, the STA ID in the RU intended for the AP 502-a may be a standard defined AID (for example, reserved for CAP or C-TDMA).

[0094] In some examples, when the AP 502-b returns the residual portion of the TXOP 514 to the AP 502-a (such as via the TXOP return frame 534), the AP 502-a may not intend to perform additional frame exchange during the residual portion of the TXOP. In such examples, after return of the TXOP 514, the TXOP 514 may end. For example, such end of the TXOP may be based on a condition such as the residual TXOP being smaller than a threshold amount of time (such as 1 millisecond) w hich may be an insufficient amount of time to perform meaningful frame exchange. In some examples, the AP 502-b may not return any sub-portion of the TXOP 514 back to the AP 502-a. For example, the AP 502-b may use the entire allocated portion of the TXOP 514. In some such examples where the AP 502-b may not return any sub-portion of the TXOP 514 back to the AP 502-a, the AP 502-b may not use the TXOP 514 once the AP 502-b shares the portion of the TXOP (for example, via the TXOP allocation frame 526).

[0095] Figure 6 shows an example of a timing diagram 600 that supports error condition management in TDMA. The timing diagram 600 may implement or may be implemented by aspects of the wireless communication network 100 or the signaling diagram 500. For example, the timing diagram 600 may include an AP 602-a and an AP 602-b, which may be examples of APs 102 as described with reference to Figure 1 or APs 502 as described with reference to Figure 5.

[0096] The AP 602-a may own or control a TXOP 614, and the AP 602-a may share one or more portions of the TXOP 614 (for example, may implement C-TDMA or coordinated spatial reuse (CSR)). For example, the AP 602-a may transmit a scheduling announcement frame 620 at or near the beginning of the TXOP 614 controlled or owned by the AP 602-a. The scheduling announcement frame 620 may announce the C- TDMA or CSR schedule to the AP 602-b. In some examples, the AP 602-b may transmit a response message 622 to the scheduling announcement frame 620. Forexample, the response message 622 to the scheduling announcement frame 620 may be a CTR message.

[0097] After the scheduling announcement frame, the AP 602-a may perform frame exchange 624 with STAs 104 served by the AP 602-a (for example, may transmit frames to or receive frames from the STAs 104 in the same BSS as the AP 602-a).

[0098] The scheduling announcement frame 620 may indicate an estimated time 632 for the TXOP allocation frame 626 which allocates or assigns a portion of the TXOP 14 to the AP 602-b. In some examples, however, the AP 602-a may not transmit the TXOP allocation frame 626 at the time expected by the AP 602-b. For example, the AP 602-a may not transmit the TXOP allocation frame 626 at the time expected by the AP 602-b if the AP 602-a cannot honor the agreement of sharing the TXOP 614 (for example, because the AP 602-a has more traffic to sen e than the AP 602-a expected when the AP 602-a transmitted the scheduling announcement frame 620) or because the TXOP allocation frame 626 is delayed to a time after the estimated time indicated by the scheduling announcement frame 620. For example, retransmissions in the BSS of the AP 602-a may cause such delays or additional traffic.

[0099] In such examples where the AP 602-a may not transmit the TXOP allocation frame 626 at the time expected by the AP 602-b, the AP 602-b may back out of an ongoing C-TDMA or CSR operation. For example, the AP 602-b may back out of an ongoing C-TDMA or CSR operation if the AP 602-b does not receive a TXOP allocation frame 626 within a timeout period 630 after the estimated time 632 of the TXOP allocation frame 626. For example, the estimated time 632 may be indicated by the scheduling announcement frame 620. In some examples, the duration of the timeout period 630 may be predefined or standardized. In some examples, the duration of the timeout period 630 may be negotiated by the AP 602-a and the AP 602-b. In some examples, the duration of the timeout period 630 may be implementation-specific for the AP 602-b. After the timeout period 630. the AP 602-b may perform a contention procedure 634 for access to the channel during the TXOP 614 so that the AP 602-b may communicate (for example, may exchange frames with) STAs 104 served by the AP 602-b.

[0100] Figure 7 shows an example of a timing diagram 700 that supports error condition management in TDMA. The timing diagram 700 may implement or may be implemented by aspects of the wireless communication network 100, the signaling diagram 500. or the timing diagram 600. For example, the timing diagram 700 may include an AP 702-a and an AP 702-b, which may be examples of APs 102 as described with reference to Figure 1, APs 502 as described with reference to Figure 5, or APs 602 as described with reference to Figure 6.

[0101] The AP 702-a may own or control a TXOP 714, and the AP 702-a may share one or more portions of the TXOP 714 (for example, may implement C-TDMA or CSR). For example, the AP 702-a may transmit a scheduling announcement frame 720 at or near the beginning of the TXOP 714 controlled or owned by the AP 702-a. The scheduling announcement frame 720 may announce the C-TDMA or CSR schedule to the AP 702-b. In some examples, the AP 702-b may transmit a response message 722 to the scheduling announcement frame 720. For example, the response message 722 to the scheduling announcement frame 720 may be a CTR message.

[0102] After the scheduling announcement frame, the AP 702-a may perform frame exchange 724 with STAs 104 served by the AP 702-a (for example, may transmit frames to or receive frames from the STAs 104 in the same BSS as the AP 702-a).

[0103] The AP 702-a may trigger TXOP sharing with the AP 702-b via transmission of a TXOP allocation frame 726. In some examples, the AP 702-a may expect the AP 702-b to transmit a response message 728 to the TXOP allocation frame 726. For example, the response message 728 expected for the TXOP allocation frame 726 may be a CTS frame. In some examples, however, the AP 702-a may not receive an expected response to the TXOP allocation frame 726. For example, the AP 702-b may not transmit a response message 728 as expected to the TXOP allocation frame 726 (such as a CTS) if the AP 702-b is busy and cannot receive or detect the TXOP allocation frame 726 from the AP 702-a. For example, the AP 702-b may be busy due to uplink access from a STA associated with the AP 702-b which may be hidden from the BSS of the AP 702-a. As another example, the AP 702-b may be busy due to access from one or more OBSS STAs 104 which set the NAV at the AP 702-b, for example, if the AP 702-a employs a short NAV during in-BSS transmissions. For example, as shown in Figure 7, the NAV may be updated multiple times by the NAV set by thescheduling announcement 742 and the NAV set by communications 740 between the AP 702-a and STAs 104. which may cause the AP 702-b to be busy during the TXOP allocation frame 726. As another example, the AP 702-b may not transmit the expected response message to the TXOP allocation frame 726 if the portion of the TXOP 714 allocated or assigned to the AP 702-b by the TXOP allocation frame 726 is insufficient for the AP 702-b. As another example, the AP 702-b may not transmit the expected response to the TXOP allocation frame 726 if the AP 702-b did not correctly receive or decode the TXOP allocation frame 726.

[0104] The AP 702-a may perform a recovery procedure 734 if the AP 702-a does not receive an expected response message to the TXOP allocation frame 726 within a timeout period 730 after the TXOP allocation frame 726. In some examples, the timeout period 730 may be equal to or based on a SIFS duration plus a slot duration plus a receive physical layer start delay (RxPHYStartDelay). For example, the AP 702-a may wait for the timeout period 730 after transmission of the TXOP allocation frame 726 before performing a recovery procedure 734. The recovery procedure 734 may request control of the channel for the TXOP 714 during the portion of the TXOP 714 that was allocated to the AP 702-b by the TXOP allocation frame 726. For example, the recovery procedure 734 may involve transmission of a frame or message to maintain or regain control of the channel during the portion of the TXOP 714 that was allocated to the AP 702-b by the TXOP allocation frame 726 in order to keep the channel busy and not allow other APs to access the channel. In some examples, the recovery procedure 734 may be a PIFS recovery or a SIFS recovery. Based on performance of the recovery procedure, the AP 702-a may perform frame exchange 736 with one or more STAs 104 served by the AP 702-a during the portion of the TXOP 714 that was allocated to the AP 702-b.

[0105] In some examples, the AP 702-a may not receive a response message 722 (such as a CTR) to the scheduling announcement frame 720 as expected. The AP 702-a may perform a similar recovery procedure in response to absence of a response message 722 to a scheduling announcement frame 720 after a timeout period as the recovery procedure 734 after the timeout period 730.

[0106] In some examples, the AP 702-a may not receive the response message 722 or the response message 728 as expected from the AP 702-b (such as a CTR in responseto the scheduling announcement frame 720 or a CTS in response to the TXOP allocation frame 726) if the AP 702-a incorrectly latched to another OBSS packet or if the AP 702-a fails to successfully decode the response message. As another example, the AP 702-b may refuse to access the shared portion of the TXOP 714. For example, to refuse the shared portion of the TXOP 714, the AP 702-b may not send the response message 722 or the response message 728 as expected (such as the CTR response to the scheduling announcement frame 720 or a CTS in response to the TXOP allocation frame 726). As another example, to refuse the shared portion of the TXOP 714, the AP 702-b may indicate the refusal through signaling in a service field (such as in a PDU 200 as described with reference to Figure 2 in a PPDU 350 as described with reference to Figure 3). As another example, to refuse the shared portion of the TXOP 714, the AP 702-b may transmit an intentionally corrupted CTS as a response message. In some examples, the AP 702-a may wait for a PIFS duration after the end of the expected response message (such as the response message 722 or the response message 728), and if the expected response message is not successfully received by the AP 702-a, the AP 702-a may take back control of the medium (for example, may perform a recovery procedure as described herein). In some examples, if the AP 702-a receives the expected response message while the AP 702-a is performing the recovery procedure, the AP 702-a may abort the recovery procedure.

[0107] Figure 8 shows an example of a timing diagram 800 that supports error condition management in TDMA. The timing diagram 800 may implement or may be implemented by aspects of the wireless communication network 100, the signaling diagram 500, the timing diagram 600, or the timing diagram 700. For example, the timing diagram 800 may include an AP 802-a, an AP 802-b, and an AP 802-c, which may be examples of APs 102 as described with reference to Figure 1, APs 502 as described with reference to Figure 5, APs 602 as described with reference to Figure 6, or APs 702 as described with reference to Figure 7.

[0108] The AP 802-a may own or control a TXOP 814, and the AP 802-a may share one or more portions of the TXOP 814 (for example, may implement C-TDMA or CSR). For example, the AP 802-a may transmit a scheduling announcement frame 820 at or near the beginning of the TXOP 814 controlled or owned by the AP 802-a. The scheduling announcement frame 820 may announce the C-TDMA or CSR schedule tothe AP 802-b and / or the AP 802-c. In some examples, the AP 802 -b may transmit a response message 822-a to the scheduling announcement frame 820 and / or the AP 802-c may transmit a response message 822-b to the scheduling announcement frame 820. For example, the AP 802-b may transmit a CTR and / or the AP 802-c may transmit a CTR.

[0109] After the scheduling announcement frame, the AP 802-a may perform frame exchange 824 with STAs 104 served by the AP 802-a (for example, may transmit frames to or receive frames from the STAs 104 in the same BSS as the AP 802-a).

[0110] The AP 802-a may trigger TXOP sharing with the AP 802-b and / or the AP 802-c via transmission of a TXOP allocation frame 826. In some examples, the AP 802-b may transmit a response message 828-a to the TXOP allocation frame 826 and / or the AP 802-c may transmit a response message 828-b to the TXOP allocation frame 826. For example, the AP 802-b may transmit a CTS frame and / or the AP 802-c may transmit a CTS frame.

[0111] In some examples, in the case where multiple devices (such as the AP 802-b, the AP 802-c, and / or one or more STAs 104) receive the scheduling announcement frame 820 and / or the TXOP allocation frame 826, the AP 802-a may receive multiple identical responses to the scheduling announcement frame 820 and / or the TXOP allocation frame 826. In such examples, if there is no response from the target shared AP, the AP 802-a may not know whether the target shared AP responded to the scheduling announcement frame 820 and / or the TXOP allocation frame 826. For example, the AP 802-b may be the target shared AP and the AP 802-c may be a candidate shared AP. The scheduling announcement frame 820 and / or the TXOP allocation frame 826 may be transmitted via a MU-RTS, and the response message 822-a and the response message 822-b, and / or and the response message 828-a and the response message 828-b may be identical CTSs. In such examples, if the AP 802-b does not transmit the response message 822-a or the response message 828-a, the AP 802-a may be unaware that the AP 802-b did not transmit the response message 822-a or the response message 828-a and thus will not use an allocated or assigned portion of the TXOP 814 if the AP 802-a receives the response message 822-b and / or the response message 828-b.

[0112] In some examples, the AP 802-a may perform a recovery procedure 834 if the AP 802-a does not receive an expected response message from the AP 802 -b (for example, the target shared AP) within a timeout period 830. For example, the recovery procedure 834 may be a recovery procedure 734 as described herein. For example, the timeout period 830 may be equal to or based on a SIFS duration plus a slot duration plus a receive physical layer start delay (RxPHYStartDelay). For example, the AP 802-a may wait for the timeout period 830 after transmission of the TXOP allocation frame 826 for a response message 828-a before performing a recovery procedure 834. As another example, the AP 802-a may wait for the timeout period 830 after transmission of the scheduling announcement frame 820 for a response message 822-a before performing a recovery procedure 834. As another example, the timeout period 830 may be a PIFS duration after the end of the expected response message (such as the response message 822-a or the response message 828-a). For example, if the AP 802-a does not receive a transmission from the AP 802-b (for example, the target shared AP) within a PIFS duration of the expected response message, the AP 802-a may perform the recovery procedure 834 to take back control of the channel. If the AP 802-a receives a response message from the AP 802-b (for example, the target shared AP) within a PIFS duration, the AP 802-a may abort or may not perform the recovery procedure 834.

[0113] In some examples, to identify which device transmitted each response message, the AP 802-a may implement a polling scheme. For example, a BSRP may be used as a trigger frame. Different RUs may be assigned to the devices (such as the AP 802-b, the AP 802-c. and / or STAs served by the AP 802-a) to respond to the scheduling announcement frame 820 and / or the TXOP allocation frame 826. In some examples, the scheduling announcement frame 820 and / or the TXOP allocation frame 826 may be an MU-RTS, and the CTS frame in response (such as the response message 822 and / or the response message 828) may be a trigger based (TB) PPDU. In such examples, the AP 802-a may know which devices responded to the trigger frame. For example, if the target AP (such as the AP 802-b) does not respond to the scheduling announcement frame using the assigned RU, the AP 802-a may not transmit a TXOP allocation frame 826. As another example, if the target AP (such as the AP 802-b) transmits the response message 822-a but does not transmit a response message 828-a to the TXOP allocationframe 826, the AP 802-a may wait for the timeout period 830 before performing the recovery procedure 834.

[0114] Figure 9 shows an example of a timing diagram 900 that supports error condition management in TDMA. The timing diagram 900 may implement or may be implemented by aspects of the wireless communication network 100. the signaling diagram 500, the timing diagram 600, the timing diagram 700, or the timing diagram 800. For example, the timing diagram 900 may include an AP 902-a, an AP 902-b, and an AP 902-c, which may be examples of APs 102 as described with reference to Figure 1, APs 502 as described with reference to Figure 5, APs 602 as described with reference to Figure 6, APs 702 as described with reference to Figure 7, or APs 802 as described with reference to Figure 8.

[0115] The AP 902-a may own or control a TXOP 914, and the AP 902-a may share one or more portions of the TXOP 914 (for example, may implement C-TDMA or CSR). For example, the AP 902-a may transmit a scheduling announcement frame 920 at or near the beginning of the TXOP 914 controlled or owned by the AP 902-a. The scheduling announcement frame 920 may announce the C-TDMA or CSR schedule to the AP 902-b and / or the AP 902-c. In some examples, the AP 902-b may transmit a response message 922-a to the scheduling announcement frame 920 and / or the AP 902-c may transmit a response message 922-b to the scheduling announcement frame 920. For example, the AP 902-b may transmit a CTR and / or the AP 902-c may transmit a CTR.

[0116] After the scheduling announcement frame, the AP 902-a may perform frame exchange 924 with STAs 104 served by the AP 902-a (for example, may transmit frames to or receive frames from the STAs 104 in the same BSS as the AP 902-a).

[0117] The AP 902-a may trigger TXOP sharing with the AP 902-b and / or the AP 902-c via transmission of a TXOP allocation frame 926. In some examples, the AP 902-b may transmit a response message 928-a to the TXOP allocation frame 926 and / or the AP 902-c may transmit a response message 928-b to the TXOP allocation frame 926. For example, the AP 902-b may transmit a CTS frame and / or the AP 902-c may transmit a CTS frame.

[0118] The response messages 922 and / or the response messages 928 may be staggered. For example, the response message 922-a may be staggered in time with respect to the response message 922-b such that the AP 902-a may identify that the response message 922-a is from the AP 902-b and the response message 922-b is from the AP 902-b. Similarly, the response message 928-a may be staggered in time with respect to the response message 928-b such that the AP 902-a may identify that the response message 928-a is from the AP 902-b and the response message 928-b is from the AP 902-b. Other responses messages 922 (for example, from STAs 104 served by the AP 902-a) may be staggered with respect to the response message 922-a and the response message 922-b and / or other response messages 928 may be staggered with respect to the response message 928-a and the response message 928-b. For example, the AP 902-a may solicit such staggered response messages as part of the frame exchanges between the AP 902-a, the AP 902-b, the AP 902-c, and / or STAs 104 served by the AP 902-a.

[0119] Based on reception of the TXOP allocation frame 926 allocating or assigning a portion of the TXOP 914 to the AP 902-b, the AP 902-b may perform frame exchange 930 with STAs 104 served by the AP 902-b (for example, may transmit frames to or receive frames from the STAs 104 in the same BSS as the AP 902-b). The AP 902-b may transmit a TXOP return frame 934 which may return control of the TXOP 914 to the AP 902-a for any unused sub-portion of the portion of the TXOP 914 assigned or allocated to the AP 902-b. For example, the AP 902-a may perform additional frame exchange with STAs 104 served by the AP 902-a using the returned sub-portion of the TXOP 914.

[0120] Figure 10 shows an example of a process flow' 1000 that supports error condition management in TDMA. The process flow' 1000 may include an AP 1002-a and an AP 1002-b, which may be examples of APs 102 as described with reference to Figure 1, APs 502 as described with reference to Figure 5, APs 602 as described with reference to Figure 6, APs 702 as described with reference to Figure 7, APs 802 as described with reference to Figure 8, or APs 902 as described with reference to Figure 9. In the follow ing description of the process flow' 1000, the operations betw een the AP 1002-a and the AP 1002-b may be transmitted in a different order than the example order shown, or the operations performed by the AP 1002-a and the AP 1002-b may beperformed in different orders or at different times. Some operations also may be omitted from the process flow 1000, and other operations may be added to the process flow 1000.

[0121] At 1004, the AP 1002-a may output a message associated with assignment of a portion of a TXOP associated with a channel. The TXOP may be controlled by the AP 1002-a. For example, the AP 1002-a may transmit the message to the AP 1002-b.

[0122] At 1006, the AP 1002-a may perform, based on an absence of a response message being obtained (for example, from the AP 1002-b) within a timeout duration associated with the message, a recovery procedure to request control of the channel during the portion of the TXOP.

[0123] In some examples, the AP 1002-a may output, prior to outputting the message at 1004, an announcement message that indicates that the AP 1002-a intends to share one or more portions of the TXOP, and the message may indicate an assignment of the portion of the TXOP. For example, the announcement message may be a scheduling announcement frame as described herein and the message may be a TXOP allocation frame as described herein. In some examples, performing the recovery procedure may include outputting or transmitting, before an expiration of a duration associated with loss of control of the TXOP. a second message associated with control of the channel. In some examples, the duration may be a PIFS that begins at an expected reception time of the response message. In some examples, the AP 1002-a may output or obtain (for example, may communicate) a data communication during the portion of the TXOP and based on outputting the second message. For example, the AP 1002-a may perform frame exchange with STAs in the same BSS as the AP 1002-a.

[0124] In some examples, at least one of the response message is expected to be obtained at a time after outputting the message, the response message is a CTR or a CTS message, or the timeout duration starts at the time after outputting the message.

[0125] In some examples, the AP 1002-a may obtain (for example, may receive), from a third device (such as another AP 102 or a STA 104), a second response to the message. In such examples the message may be output to a set of wireless communication devices that include the AP 1002-b and the third wireless communication device, and the message may indicate an assignment of the portion ofthe TXOP to the third wireless communication device. In some examples, the AP 1002-a may output (for example, may transmit) an indication of a set of respective response periods associated with responding to the message for each wireless communication device of the set of wireless communication devices, where response periods of the set of respective response periods are staggered in time, where the second response is obtained via a second response period of the set of respective response periods associated with the third device, and where the response message is expected in a first response period of the set of respective response periods associated with the AP 1002-b. In some examples, the AP 1002-a may output (for example, may transmit) an indication of a set of respective RUs associated with responding to the message for each wireless communication device of a set of multiple wireless communication devices including the AP 1002-b, and the message may indicate that the AP 1002-a intends to share one or more portions of the TXOP with the set of multiple wireless communication devices.

[0126] In some examples, the AP 1002-a may output, via the message at 1004, an indication of an assignment of a second portion of the TXOP for the channel. The AP 1002-a may obtain (for example, may receive) a second message that indicates a time within the second portion that control of the channel will return to the AP 1002-a. The AP 1002-a may output or obtain (for example, may communicate) a data communication during the portion of the TXOP and based on the second message.

[0127] In some examples, the TXOP is a C-TDMA period assigned to the AP 1002-a. In some examples, the portion is a spatial reuse service period (for example, the portion of the TXOP may be used for CSR). For example, the AP 1002-a may share a service period within the TXOP with the AP 1002-b and / or one or more other APs. The AP 1002-a also may communicate with STAs served by the AP 1002-a during a shared sendee period.

[0128] Figure 11 shows an example of a process flow 1100 that supports error condition management in TDMA. The process flow 1100 may include an AP 1102-a and an AP 1102-b, which may be examples of APs 102 as described with reference to Figure 1, APs 502 as described with reference to Figure 5, APs 602 as described with reference to Figure 6, APs 702 as described with reference to Figure 7, APs 802 as described with reference to Figure 8, or APs 902 as described with reference to Figure9. In the following description of the process flow 1100, the operations between the AP 1102-a and the AP 1102-b may be transmitted in a different order than the example order shown, or the operations performed by the AP 1102-a and the AP 1102-b may be performed in different orders or at different times. Some operations also may be omitted from the process flow 1100, and other operations may be added to the process flow 1100.

[0129] At 1104, the AP 1102-b may obtain (for example, may receive from the AP 1102-a) a first message that indicates sharing of one or more portions of a TXOP for a channel with the AP 1102-b. For example, the AP 1102-a may own or may control the TXOP.

[0130] At 1 106, the AP 1 102-b may perform a contention procedure for the channel during the TXOP based on an absence of a second message being obtained within a timeout duration associated with the first message, the second message associated with assignment of a portion of the TXOP to the AP 1102-b. For example, the second message may be a TXOP allocation frame as described herein expected based on the first message being a scheduling announcement frame as described herein.

[0131] In some examples, the AP 1102-b may output or obtain (for example, communicate) a data communication during the TXOP and after performance of the contention procedure. For example, the AP 1102-b may communicate with one or more STAs during the TXOP.

[0132] In some examples, the timeout duration may be based on an expected time for obtaining of the second message.

[0133] In some examples, the AP 1102-b may output (for example, may transmit) a response message to the first message, and the expected time for obtaining the second message may be based on the response message. In some examples, the AP 1102-b may obtain (for example, may receive from the AP 1102-a) an indication of a response period for outputting the response message, and the response message may be output in accordance with the response period. In some examples, the AP 1102-b may obtain (for example, may receive from the AP 1102-a) an indication of a RU for output of the response message, and the response message may be output using the RU. In someexamples, the first message may indicate the expected time for obtaining the second message.

[0134] In some examples, the AP 1102-b may obtain (for example, may receive) an indication of the timeout duration from the AP 1102-b.

[0135] Figure 12 shows a block diagram of an example wireless communication device 1200 that supports error condition management in TDM A. In some examples, the wireless communication device 1200 is configured to perform the processes 1300 and 1400 described with reference to Figures 13 and 14, respectively. The wireless communication device 1200 may include one or more chips, SoCs, chipsets, packages, components or devices that individually or collectively constitute or include a processing system. The processing system may interface with other components of the wireless communication device 1200, and may generally process information (such as inputs or signals) received from such other components and output information (such as outputs or signals) to such other components. In some aspects, an example chip may include a processing system, a first interface to output or transmit information and a second interface to receive or obtain information. For example, the first interface may refer to an interface between the processing system of the chip and a transmission component, such that the wireless communication device 1200 may transmit the information output from the chip. In such an example, the second interface may refer to an interface between the processing system of the chip and a reception component, such that the wireless communication device 1200 may receive information that is then passed to the processing system. In some such examples, the first interface also may obtain information, such as from the transmission component, and the second interface also may output information, such as to the reception component.

[0136] Further, various components of the wireless communication device 1200 may provide means for performing the methods described herein. In some examples, means for transmitting and / or receiving may include the transceivers and / or antenna(s) of the wireless communication device 1200. In some examples, means for outputting or sending (such as means for outputting for transmission) and means for obtaining (such as means for obtaining after information is received from a different device) may include one or more interfaces of the wireless communication device 1200 to output signals to other components or obtain signals from other components of the wirelesscommunication device 1200. For example, a processor (of a processing system) may output (such as provide) signals and / or data, via a bus interface, to a radio frequency front end for transmission. Similarly, rather than actually receiving signals and / or data, a device may have an interface to obtain the signals and / or data received from another device (a means for obtaining). For example, a processor (of a processing system) may obtain (or receive) the signals and / or data, via a bus interface, from a radio frequency front end for reception. In various aspects, a radio frequency front end may include various components, including transmit and receive processors, transmit and receive M1M0 processors, modulators, demodulators, and the like. Each of means for performing and communicating include a processing system, processor circuitry (including one or more processors), memory’ circuitry7, and / or computer-readable media of the wireless communication device 1200.

[0137] The processing system of the wireless communication device 1200 includes processor (or “processing”) circuitry in the form of one or multiple processors, microprocessors, processing units (such as central processing units (CPUs), graphics processing units (GPUs), neural processing units (NPUs) (also referred to as neural network processors or deep learning processors (DLPs)), or digital signal processors (DSPs)), processing blocks, application-specific integrated circuits (ASIC). programmable logic devices (PLDs) (such as field programmable gate arrays (FPGAs)), or other discrete gate or transistor logic or circuitry (all of which may be generally referred to herein individually as “processors” or collectively as “the processor” or “the processor circuitry”). One or more of the processors may be individually or collectively configurable or configured to perform various functions or operations described herein. The processing system may further include memory7circuitry in the form of one or more memory7devices, memory7blocks, memory7elements or other discrete gate or transistor logic or circuitry, each of which may include tangible storage media such as randomaccess memory (RAM) or ROM, or combinations thereof (all of which may be generally referred to herein individually as “memories” or collectively as “the memory” or “the memory' circuitry ”). One or more of the memories may be coupled with one or more of the processors and may individually or collectively store processor-executable code that, when executed by one or more of the processors, may configure one or more of the processors to perform various functions or operations described herein.Additionally, or alternatively, in some examples, one or more of the processors may be preconfigured to perform various functions or operations described herein without requiring configuration by software. The processing system may further include or be coupled with one or more modems (such as a Wi-Fi (for example, IEEE compliant) modem or a cellular (for example, 3GPP 4G LTE, 5G or 6G compliant) modem). In some implementations, one or more processors of the processing system include or implement one or more of the modems. The processing system may further include or be coupled with multiple radios (collectively “the radio”), multiple RF chains or multiple transceivers, each of which may in turn be coupled with one or more of multiple antennas. In some implementations, one or more processors of the processing system include or implement one or more of the radios, RF chains or transceivers.

[0138] In some examples, the wireless communication device 1200 can be configurable or configured for use in an AP. such as the AP 102 described with reference to Figure 1. In some other examples, the wireless communication device 1200 can be an AP that includes such a processing system and other components including 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 1200 can be configurable or configured 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 other examples, the wireless communication device 1200 can be configurable or configured to transmit and receive signals and communications conforming to one or more 3GPP specifications including those for 5GNR or 6G. In some examples, the wireless communication device 1200 also includes or can be coupled with one or more application processors which may be further coupled with one or more other memories. In some examples, the wireless communication device 1200 further includes at least one external network interface coupled with the processing system that enables communication with a core network or backhaul network that enables the wireless communication device 1200 to gain access to external networks including the Internet.

[0139] The wireless communication device 1200 includes a TXOP sharing indication manager 1225, a recovery procedure manager 1230, a TXOP sharingannouncement manager 1235, a contention procedure manager 1240, a response message manager 1245, a response message RU manager 1250, a TXOP sharing assignment manager 1255, a channel control return manager 1260, a data communication manager 1265, a timeout duration manager 1270. and a response message timing manager 1275. Portions of one or more of the TXOP sharing indication manager 1225, the recovery procedure manager 1230, the TXOP sharing announcement manager 1235, the contention procedure manager 1240, the response message manager 1245. the response message RU manager 1250, the TXOP sharing assignment manager 1255. the channel control return manager 1260, the data communication manager 1265, the timeout duration manager 1270, and the response message timing manager 1275 may be implemented at least in part in hardware or firmware. For example, one or more of the TXOP sharing indication manager 1225, the recovery procedure manager 1230, the TXOP sharing announcement manager 1235, the contention procedure manager 1240, the response message manager 1245, the response message RU manager 1250, the TXOP sharing assignment manager 1255, the channel control return manager 1260, the data communication manager 1265, the timeout duration manager 1270, and the response message timing manager 1275 may be implemented at least in part by at least a processor or a modem. In some examples, portions of one or more of the TXOP sharing indication manager 1225, the recovery procedure manager 1230, the TXOP sharing announcement manager 1235, the contention procedure manager 1240, the response message manager 1245, the response message RU manager 1250, the TXOP sharing assignment manager 1255. the channel control return manager 1260, the data communication manager 1265, the timeout duration manager 1270, and the response message timing manager 1275 may be implemented at least in part by a processor and software in the form of processor-executable code stored in memory.

[0140] The wireless communication device 1200 may support wireless communications in accordance with examples as disclosed herein. The TXOP sharing indication manager 1225 is configurable or configured to output a message associated with assignment of a portion of a TXOP associated with a channel. The recovery' procedure manager 1230 is configurable or configured to perform, based on an absence of a response message being obtained within a timeout duration associated with themessage, a recovery procedure to request control of the channel during the portion of the TXOP.

[0141] In some examples, the TXOP sharing announcement manager 1235 is configurable or configured to output, prior to outputting the message, an announcement message that indicates that the apparatus intends to share one or more portions of the TXOP, where the message indicates an assignment of the portion of the TXOP.

[0142] In some examples, to support performing the recovery procedure, the recovery procedure manager 1230 is configurable or configured to output, before an expiration of a duration associated with loss of control of the TXOP, a second message associated with control of the channel.

[0143] In some examples, the duration is a distributed coordination function interframe space that begins at an expected reception time of the response message.

[0144] In some examples, the data communication manager 1265 is configurable or configured to output or obtain, during the portion of the TXOP and after outputting the second message, a data communication.

[0145] In some examples, the timeout duration starts after or when the message has been or is output.

[0146] In some examples, the data communication manager 1265 is configurable or configured to output or obtain, during the TXOP and prior to outputting the message, a data communication.

[0147] In some examples, the response message is expected to be obtained at a time after outputting the message. In some examples, the response message is a CTR or a CTS message. In some examples, the timeout duration starts at the time after outputting the message.

[0148] In some examples, the response message manager 1245 is configurable or configured to obtain, from a second apparatus, a second response to the message, where the message is output to a set of apparatuses including the second apparatus and a third apparatus, where the message indicates an assignment of the portion of the TXOP to the third apparatus.

[0149] In some examples, the response message RU manager 1250 is configurable or configured to output an indication of a set of respective RUs associated with responding to the message for each apparatus of the set of apparatuses, where at least one of the second response is obtained via a second RU of the set of respective RUs associated with the second apparatus or the response message is expected in a first RU of the set of respective RUs associated with the third apparatus.

[0150] In some examples, the response message timing manager 1275 is configurable or configured to output an indication of a set of respective response periods associated with responding to the message for each apparatus of the set of apparatuses, where response periods of the set of respective response periods are staggered in time, where at least one of the second response is obtained via a second response period of the set of respective response periods associated with the second apparatus or the response message is expected in a first response period of the set of respective response periods associated with the third apparatus.

[0151] In some examples, to support outputting the message, the response message RU manager 1250 is configurable or configured to output an indication of a set of respective RUs associated with responding to the message for each apparatus of a set of multiple apparatuses, where the message indicates that the apparatus intends to share one or more portions of the TXOP with the set of multiple apparatuses.

[0152] In some examples, the TXOP sharing assignment manager 1255 is configurable or configured to output, via the message, an indication of an assignment of a second portion of the TXOP for the channel. In some examples, the channel control return manager 1260 is configurable or configured to obtain a second message that indicates a time within the second portion that control of the channel will return to the apparatus. In some examples, the data communication manager 1265 is configurable or configured to output or obtain, during the portion of the TXOP and after the second message, a data communication.

[0153] In some examples, the TXOP is a coordinated TDMA period assigned to the apparatus.

[0154] In some examples, portion is a spatial reuse service period.

[0155] Additionally, or alternatively, the wireless communication device 1200 may support wireless communications in accordance with examples as disclosed herein. The TXOP sharing announcement manager 1235 is configurable or configured to obtain a first message that indicates sharing of one or more portions of a TXOP associated with a channel. The contention procedure manager 1240 is configurable or configured to perform a contention procedure for the channel during the TXOP based on an absence of a second message being obtained within a timeout duration associated with the first message, the second message being associated with assignment of a portion of the TXOP to the apparatus.

[0156] In some examples, the data communication manager 1265 is configurable or configured to output or obtain, during the TXOP and after performance of the contention procedure, a data communication.

[0157] In some examples, the timeout duration is based on an expected time for obtaining of the second message.

[0158] In some examples, the response message manager 1245 is configurable or configured to output a response message to the first message, where the expected time for obtaining the second message is based on the response message.

[0159] In some examples, the response message timing manager 1275 is configurable or configured to obtain an indication of a response period for outputting the response message, where the response message is output in accordance with the response period.

[0160] In some examples, the response message RU manager 1250 is configurable or configured to obtain an indication of a RU for output of the response message, where the response message is output using the RU.

[0161] In some examples, the first message indicates the expected time for obtaining of the second message.

[0162] In some examples, the timeout duration manager 1270 is configurable or configured to obtain an indication of the timeout duration.

[0163] Figure 13 shows a flowchart illustrating an example process 1300 performable by or at an apparatus that supports error condition management in TDMA.The operations of the process 1300 may be implemented by an apparatus or its components as described herein. For example, the process 1300 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. In some examples, the process 1300 may be performed by a wireless AP, such as one of the APs 102 described with reference to Figure 1.

[0164] In some examples, in 1305, the apparatus may output a message associated with assignment of a portion of a TXOP associated with a channel. The operations of 1305 may be performed in accordance with examples as disclosed herein. In some implementations, aspects of the operations of 1305 may be performed by a TXOP sharing indication manager 1225 as described with reference to Figure 12.

[0165] In some examples, in 1310, the apparatus may perform, based on an absence of a response message being obtained within a timeout duration associated with the message, a recovery procedure to request control of the channel during the portion of the TXOP. The operations of 1310 may be performed in accordance with examples as disclosed herein. In some implementations, aspects of the operations of 1310 may be performed by a recovery' procedure manager 1230 as described with reference to Figure 12.

[0166] Figure 14 shows a flowchart illustrating an example process 1400 performable by or at an apparatus that supports error condition management in TDMA. The operations of the process 1400 may be implemented by an apparatus or its components as described herein. For example, the process 1400 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. In some examples, the process 1400 may be performed by a wireless AP, such as one of the APs 102 described with reference to Figure 1.

[0167] In some examples, in 1405, the apparatus may obtain a first message that indicates sharing of one or more portions of a TXOP associated with a channel. The operations of 1405 may be performed in accordance with examples as disclosed herein. In some implementations, aspects of the operations of 1405 may be performed by a TXOP sharing announcement manager 1235 as described with reference to Figure 12.

[0168] In some examples, in 1410, the apparatus may perform a contention procedure for the channel during the TXOP based on an absence of a second message being obtained within a timeout duration associated with the first message, the second message being associated with assignment of a portion of the TXOP to the apparatus. The operations of 1410 may be performed in accordance with examples as disclosed herein. In some implementations, aspects of the operations of 1410 may be performed by a contention procedure manager 1240 as described with reference to Figure 12.

[0169] Implementation examples are described in the following numbered clauses:

[0170] The following provides an overview of aspects of the present disclosure:

[0171] Aspect 1 : A method for wireless communications at a wireless node, including: outputting a message associated with assignment of a portion of a TXOP associated with a channel; and performing, based at least in part on an absence of a response message being obtained within a timeout duration associated with the message, a recovery procedure to request control of the channel during the portion of the TXOP.

[0172] Aspect 2: The method of aspect 1, further including: outputting, prior to outputting the message, an announcement message that indicates that the wireless node intends to share one or more portions of the TXOP, where the message indicates an assignment of the portion of the TXOP.

[0173] Aspect 3: The method of aspect 2, where performing the recovery procedure includes: outputting, before an expiration of a duration associated with loss of control of the TXOP. a second message associated with control of the channel.

[0174] Aspect 4: The method of aspect 3, where the duration is a distributed coordination function interframe space that begins at an expected reception time of the response message.

[0175] Aspect 5: The method of any of aspects 3-4, further including: outputting or obtaining, during the portion of the TXOP and after outputting the second message, a data communication.

[0176] Aspect 6: The method of any of aspects 1-5, where the timeout duration starts after or when the message has been or is output.

[0177] Aspect 7: The method of any of aspects 2-6, further including: outputting or obtaining, during the TXOP and prior to outputting the message, a data communication.

[0178] Aspect 8: The method of any of aspects 1-7, where at least one of the response message is expected to be obtained at a time after outputting the message, the response message is a CTR or a CTS message, or the timeout duration starts at the time after outputting the message.

[0179] Aspect 9: The method of any of aspects 1-8, further including: obtaining, from a second wireless node, a second response to the message, where the message is output to a set of wireless nodes including the second wireless node and a third wireless node, where the message indicates an assignment of the portion of the TXOP to the third wireless node.

[0180] Aspect 10: The method of aspect 9, further including: outputting an indication of a set of respective RUs associated with responding to the message for each wireless node of the set of wireless nodes, where at least one of the second response is obtained via a second RU of the set of respective RUs associated with the second wireless node or the response message is expected in a first RU of the set of respective RUs associated with the third wireless node.

[0181] Aspect 11 : The method of any of aspects 9-10, further including: outputting an indication of a set of respective response periods associated with responding to the message for each wireless node of the set of wireless nodes, where response periods of the set of respective response periods are staggered in time, where at least one of the second response is obtained via a second response period of the set of respective response periods associated with the second wireless node or the response message is expected in a first response period of the set of respective response periods associated with the third wireless node.

[0182] Aspect 12: The method of any of aspects 1-11, where outputting the message includes: outputting an indication of a set of respective RUs associated with responding to the message for each wireless node of a plurality of wireless nodes, where the message indicates that the wireless node intends to share one or more portions of the TXOP with the plurality of wireless nodes.

[0183] Aspect 13: The method of any of aspects 1-12, where message includes an indication of an assignment of a second portion of the transmission opportunity for the channel, the method further including: obtaining a second message that indicates a time within the second portion that control of the channel will return to the wireless node; and outputting or obtaining, during the portion of the TXOP and after the second message, a data communication.

[0184] Aspect 14: The method of any of aspects 1-13, where the TXOP is a C- TDMA period assigned to the wireless node.

[0185] Aspect 15: The method of any of aspects 1-13, where portion is a spatial reuse service period.

[0186] Aspect 16: A method for wireless communications at an wireless node, including: obtaining a first message that indicates sharing of one or more portions of a TXOP associated with a channel; and performing a contention procedure for the channel during the TXOP based at least in part on an absence of a second message being obtained within a timeout duration associated with the first message, the second message being associated with assignment of a portion of the TXOP to the wireless node.

[0187] Aspect 17: The method of aspect 16, further including: outputting or obtaining, during the TXOP and after performance of the contention procedure, a data communication.

[0188] Aspect 18: The method of any of aspects 16-17. where the timeout duration is based at least in part on an expected time for obtaining of the second message.

[0189] Aspect 19: The method of aspect 18, further including: outputting a response message to the first message, where the expected time for obtaining the second message is based at least in part on the response message.

[0190] Aspect 20: The method of aspect 19. further including: obtaining an indication of a response period for outputting the response message, where the response message is output in accordance with the response period.

[0191] Aspect 21 : The method of any of aspects 19-20, further including: obtaining an indication of a RU for output of the response message, where the response message is output using the RU.

[0192] Aspect 22: The method of any of aspects 18-21, where the first message indicates the expected time for obtaining of the second message.

[0193] Aspect 23: The method of any of aspects 16-22, further including: obtaining an indication of the timeout duration.

[0194] Aspect 24: An apparatus for wireless communications, including one or more memories storing processor-executable code, one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the apparatus to perform a the method of any of aspects 1-15.

[0195] Aspect 25: An apparatus for wireless communications, including at least one means for performing a method of any of aspects 1-15.

[0196] Aspect 26: A non-transitory computer-readable medium storing code for wireless communications, the code including instructions executable by one or more processors to perform a method of any of aspects 1-15.

[0197] Aspect 27: An AP, including, at least one transceiver; and a processing system that includes processor circuitry and memory circuitry that stores code, the processing system configured to cause the AP to perform a method of any of aspects 1- 15, where the at least one transceiver is configured to transmit the message associated with assignment of the portion of the TXOP for sharing.

[0198] Aspect 28: An apparatus for wireless communications, including one or more memories storing processor-executable code, and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the apparatus to perform a method of any of aspects 16-23.

[0199] Aspect 29: An apparatus for wireless communications, including at least one means for performing a method of any of aspects 16-23.

[0200] Aspect 30: A non-transitory computer-readable medium storing code for wireless communications, the code including instructions executable by one or more processors to perform a method of any of aspects 16-23.

[0201] Aspect 31 : An AP, including, at least one transceiver; and a processing system that includes processor circuitry and memory circuitry that stores code, the processing system configured to cause the AP to perform a method of any of aspects 1 -23, where the transceiver is configured to receive the first message that indicates sharing of the one or more portions of the transmission opportunity for the channel.

[0202] 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.

[0203] 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.

[0204] 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 isthat 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.

[0205] 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.

[0206] 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 examples shown herein, but are to be accorded the w idest scope consistent with this disclosure, the principles and the novel features disclosed herein.

[0207] 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.

[0208] Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may. however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided sothat this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

[0209] 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

CLAIMSWhat is claimed is:

1. An apparatus for wireless communications, comprising: a processing system that includes processor circuitry and memory circuitry that stores code, the processing system configured to cause the apparatus to: output a message associated with assignment of a portion of a transmission opportunity associated with a channel; and perform, based at least in part on an absence of a response message being obtained within a timeout duration associated with the message, a recovery procedure to request control of the channel during the portion of the transmission opportunity.

2. The apparatus of claim 1, wherein the processing system is further configured to cause the apparatus to: output, prior to outputting the message, an announcement message that indicates that the apparatus intends to share one or more portions of the transmission opportunity, wherein the message indicates an assignment of the portion of the transmission opportunity.

3. The apparatus of claim 2, wherein, to perform the recovery procedure, the processing system is configured to cause the apparatus to: output, before an expiration of a duration associated with loss of control of the transmission opportunity, a second message associated with control of the channel.

4. The apparatus of claim 3. wherein the duration is a distributed coordination function interframe space that begins at an expected reception time of the response message.

5. The apparatus of claim 3. wherein the processing system is further configured to cause the apparatus to: output or obtain, during the portion of the transmission opportunity and after outputting the second message, a data communication.

6. The apparatus of claim 1 , wherein the timeout duration starts after or when the message has been or is output.

7. The apparatus of claim 1. wherein at least one of: the response message is expected to be obtained at a time after outputting the message, the response message is a control response or a clear to send message, or the timeout duration starts at the time after outputting the message.

8. The apparatus of claim 1, wherein the processing system is further configured to cause the apparatus to: obtain, from a second apparatus, a second response to the message, wherein at least one of the message is output to a set of apparatuses comprising the second apparatus and a third apparatus or the message indicates an assignment of the portion of the transmission opportunity' to the third apparatus.

9. The apparatus of claim 8. wherein the processing system is further configured to cause the apparatus to: output an indication of a set of respective resource units associated yvith responding to the message for each apparatus of the set of apparatuses, wherein at least one of the second response is obtained via a second resource unit of the set of respective resource units associated with the second apparatus or the response message is expected in a first resource unit of the set of respective resource units associated with the third apparatus.

10. The apparatus of claim 8, wherein the processing system is further configured to cause the apparatus to: output an indication of a set of respective response periods associated with responding to the message for each apparatus of the set of apparatuses, wherein response periods of the set of respective response periods are staggered in time, wherein at least one of the second response is obtained via a second response period of the set of respective response periods associated with the second apparatus or the response message is expected in a first response period of the set of respective response periods associated with the third apparatus.1 1 . The apparatus of claim 1 , wherein, to output the message, the processing system is configured to cause the apparatus to: output an indication of a set of respective resource units associated with responding to the message for each apparatus of a plurality of apparatuses, wherein the message indicates that the apparatus intends to share one or more portions of the transmission opportunity with the plurality of apparatuses.

12. The apparatus of claim 1. wherein the message includes an indication of an assignment of a second portion of the transmission opportunity for the channel, wherein the processing system is further configured to cause the apparatus to: obtain a second message that indicates a time within the second portion that control of the channel will return to the apparatus; and output or obtain, during the portion of the transmission opportunity and after the second message, a data communication.

13. The apparatus of claim 1, wherein the transmission opportunity is a coordinated time division multiple access period assigned to the apparatus.

14. The apparatus of claim 1, wherein the portion is a spatial reuse service period.

15. The apparatus of claim 1, further comprising: a transceiver configured to transmit the message, wherein the apparatus comprises an access point.

16. An apparatus for wireless communications, comprising: a processing system that includes processor circuitry' and memory' circuitry that stores code, the processing system configured to cause the apparatus to: obtain a first message that indicates sharing of one or more portions of a transmission opportunity associated with a channel; and perform a contention procedure for the channel during the transmission opportunity based at least in part on an absence of a second message being obtained within a timeout duration associated with the first message, the second message being associated with assignment of a portion of the transmission opportunity to the apparatus.

17. The apparatus of claim 16, wherein the processing system is further configured to cause the apparatus to: output or obtain, during the transmission opportunity, a data communication.

18. The apparatus of claim 16, wherein the timeout duration is based at least in part on an expected time for obtaining of the second message.

19. The apparatus of claim 18, wherein the processing system is further configured to cause the apparatus to: output a response message to the first message, wherein the expected time for obtaining the second message is based at least in part on the response message.

20. The apparatus of claim 19, wherein the processing system is further configured to cause the apparatus to: obtain an indication of a response period for outputting the response message, wherein the response message is output in accordance with the response period.

21. The apparatus of claim 19, wherein the processing system is further configured to cause the apparatus to: obtain an indication of a resource unit for output of the response message, wherein the response message is output using the resource unit.

22. The apparatus of claim 18, wherein the first message indicates the expected time for obtaining of the second message.

23. The apparatus of claim 16, wherein the processing system is further configured to cause the apparatus to: obtain an indication of the timeout duration.

24. The apparatus of claim 16, further comprising: a transceiver configured to receive the first message, wherein the apparatus comprises an access point.

25. A method for wireless communications at a wireless node, comprising: outputting a message associated with assignment of a portion of a transmission opportunity associated with a channel; and performing, based at least in part on an absence of a response message being obtained within a timeout duration associated with the message, a recovery procedure to request control of the channel during the portion of the transmission opportunity.

26. A method for wireless communications at a wireless node, comprising: obtaining a first message that indicates sharing of one or more portions of a transmission opportunity associated with a channel; and performing a contention procedure for the channel during the transmission opportunity based at least in part on an absence of a second message being obtained within a timeout duration associated with the first message, the second message being associated with assignment of a portion of the transmission opportunity to the wireless node.

Images