Using a multi-station block acknowledgement frame as an initial control response frame

Abstract

Disclosed herein is a method performed by a candidate shared access point (AP) during a coordinated time division multiple access (c-TDMA) polling phase. The method includes receiving an initial control frame from the sharing AP that polls the candidate shared AP regarding participating in c-TDMA and transmitting an initial control response frame to the sharing AP, wherein the initial control response frame comprises a multi-station block acknowledgement frame that includes a block acknowledgement bitmap field that is repurposed to carry information regarding a willingness of the candidate shared AP to participate in the c-TDMA.

Description

SPECIFICATIONUSING A MULTI-STATION BLOCK ACKNOWLEDGEMENT FRAME AS AN INITIAL CONTROL RESPONSE FRAMECROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 777,435, filed March 25, 2025, titled “Architecture of ICF / ICR in Multi-AP Scheme for Beyond IEEE 802.1 Ibe”, which is hereby incorporated by reference.TECHNICAL FIELD

[0002] The present disclosure generally relates to wireless communications, and more specifically, relates to using a multi-station block acknowledgement frame as an initial control response frame.BACKGROUND

[0003] Institute of Electrical and Electronics Engineers (IEEE) 802.11 is a set of standards for implementing wireless local area network communication in various frequencies, including but not limited to the 2.4 gigahertz (GHz), 5 GHz, 6 GHz, and 60 GHz bands. These standards define the protocols that enable Wi-Fi devices to communicate with each other. TheIEEE 802.11 family of standards has evolved over time to accommodate higher data rates, improved security, and better performance in different environments. Some of the most widely used standards include 802.11a, 802.11b, 802.11g, 802.1 In, 802.1 lac, and 802.1 lax (also known as “Wi-Fi 6”). These standards specify the modulation techniques, channel bandwidths, and other technical aspects that facilitate interoperability between devices from various manufacturers. IEEE 802.11 has played an important role in the widespread adoption of wireless networking in homes, offices, and public spaces, enabling users to connect their devices to the internet and each other without the need for wired connections.

[0004] IEEE 802.1 Ibe, also known as “Wi-Fi 7”, is the next generation of the IEEE 802.11 family of standards for wireless local area networks. Currently under development, 802.1 Ibe aims to significantly improve upon the capabilities of its predecessor, 802.1 lax / Wi-Fi 6, by offering even higher data rates, lower latency, and increased reliability. The standard is expected to leverage advanced technologies such as multi-link operation (MLO), which allows devices to simultaneously use multiple frequency bands and channels for enhanced performance andDocket No. 1002P25009W01Client Matter No. P25-009W01reliability. Additionally, 802. llbe will introduce 4096-QAM (Quadrature Amplitude Modulation), enabling higher data rates by encoding more bits per symbol. The standard will also feature improved medium access control (MAC) efficiency, enhanced power saving capabilities, and better support for high-density environments. With theseadvancements, 802.1 Ibe is expected to deliver theoretical maximum data rates of up to 46 gigabits per second (Gbps), making it suitable for bandwidth-intensive applications such as virtual and augmented reality, 8K video streaming, and high-performance gaming.

[0005] Coordinated time division multiple access (C-TDMA or c-TDMA) is a multi-AP coordination scheme that allows an access point (AP) to share its transmission opportunity (TXOP) with other AP(s). For example, with c-TDMA, a first AP that owns a TXOP may share a portion of the TXOP with a second AP. The second AP may then transmit and receive in its basic service set (BSS) during the allocated portion of the TXOP. Stated differently, the first AP may allocate a portion of the TXOP to the second AP to allow the second AP to transmit and receive with its associated non-AP stations (STAs) during the allocated portion of the TXOP even though the second AP is not the original TXOP owner. In such a TXOP sharing scenario, the first AP may be referred to as the sharing AP and the second AP may be referred to as the shared AP.

[0006] During a polling phase of c-TDMA, the sharing AP may poll candidate shared APs regarding their interest in participating in c-TDMA. The sharing AP may select one or more of the candidate shared APs to participate in c-TDMA based on the responses received from the candidate shared APs during the polling phase. However, the sharing AP may end up selecting candidate shared APs in a sub-optimal manner because it does not know the current situations of the candidate shared APs.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The disclosure will be more fully understood from the detailed description provided below and the accompanying drawings that depict various embodiments of the disclosure.However, these drawings should not be interpreted as limiting the disclosure to the specific embodiments shown; they are provided for explanation and understanding only.

[0008] Figure 1 illustrates an example of a wireless local area network (WLAN) with a basic service set (BSS) that includes multiple wireless devices, in accordance with some embodiments of the present disclosure.

[0009] Figure 2 is a schematic diagram of a wireless device, in accordance with some embodiments of the present disclosure.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0010] Figure 3 A illustrates components of a wireless device configured to transmit data, in accordance with some embodiments of the present disclosure.

[0011] Figure 3B illustrates components of a wireless device configured to receive data, in accordance with some embodiments of the present disclosure.

[0012] Figure 4 illustrates interframe space (IFS) relationships, in accordance with some embodiments of the present disclosure.

[0013] Figure 5 illustrates a Carrier Sense Multiple Access with Collision Avoidance (CSMAZCA)-based frame transmission procedure, in accordance with some embodiments of the present disclosure.

[0014] Figure 6 illustrates maximum physical layer (PHY) rates for Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, in accordance with some embodiments of the present disclosure.

[0015] Figure 7 provides a detailed description of fields in Extremely High Throughput (EHT) Physical Protocol Data Unit (PPDU) frames, including their purposes and characteristics, in accordance with some embodiments of the present disclosure.

[0016] Figure 8 illustrates an example of multi-user (MU) transmission in Orthogonal Frequency-Division Multiple Access (OFDMA), in accordance with some embodiments of the present disclosure.

[0017] Figure 9 illustrates an example of an access point sending a trigger frame to multiple associated stations and receiving Uplink Orthogonal Frequency-Division Multiple Access Trigger-Based Physical Protocol Data Units (UL OFDMA TB PPDUs) in response, in accordance with some embodiments of the present disclosure.

[0018] Figure 10 is a diagram showing a frame exchange sequence where the sharing access point (AP) polls a candidate shared AP regarding its interest in participating in coordinated time division multiple access (c-TDMA), selects the candidate shared AP to be the final shared AP for c-TDMA, and shares the transmission opportunity (TXOP) with the candidate shared AP, according to some embodiments.

[0019] Figure 11 is a diagram showing a frame exchange sequence where the sharing AP transmits an initial control frame to multiple candidate shared APs and only one of the candidate shared APs respond to the initial control frame and participates in c-TDMA, according to some embodiments.

[0020] Figure 12 is a diagram showing a multiple station block acknowledgement (multi-STA BA) frame format, according to some embodiments.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0021] Figure 13 is a diagram showing details of the per association identifier (AID) traffic identifier (TID) info field format, according to some embodiments.

[0022] Figure 14 is a diagram showing a block acknowledgement (ACK) bitmap field format for providing an indication of a candidate shared AP’s interest in participating in c-TDMA, according to some embodiments.

[0023] Figure 15 is a diagram showing a block ACK bitmap field format for providing an indication of a candidate shared AP’s interest in participating in c-TDMA and traffic characteristic information of traffic that the candidate shared AP wishes to process, according to some embodiments.

[0024] Figure 16 is a diagram showing a block ACK bitmap field format for providing traffic characteristic information of traffic that the candidate shared AP wishes to process, according to some embodiments.

[0025] Figure 17 is a diagram showing a block ACK bitmap field format for providing information regarding the estimated processing time and information regarding the maximum allowable delay, according to some embodiments.

[0026] Figure 18 is a diagram showing a block ACK bitmap field format for providing dynamic unavailability operation (DUO) information, according to some embodiments.

[0027] Figure 19 is a diagram showing a block ACK bitmap filed format for providing information regarding the estimated processing time and DUO information, according to some embodiments.

[0028] Figure 20 is a flow diagram of a method for providing feedback information, according to some embodiments.

[0029] Figure 21 is a flow diagram of a method for polling candidate shared APs, according to some embodiments.DETAILED DESCRIPTION

[0030] The present disclosure generally relates to wireless communications, and more specifically, relates to using a multi-station block acknowledgement (multi-STA BA) frame as an initial control response frame.

[0031] Performing coordinated time division multiple access (c-TDMA) may involve a polling phase and a transmission opportunity (TXOP) allocation phase. During the polling phase, a sharing access point (AP) may poll candidate shared APs regarding their interest in participating in c-TDMA. For example, during the polling phase, the sharing AP may transmit an initial control frame (ICF) to poll candidate sharing APs regarding their interest in participating in c-Docket No. 1002P25009W01Client Matter No. P25-009W01TDMA. Candidate shared APs that receive the initial control frame may transmit an initial control response frame (ICR) to the sharing AP indicating whether they are interested in participating in the c-TDMA. The sharing AP may select one or more of the candidate shared APs that expressed interest in participating in the c-TDMA to participate in the c-TDMA.During the TXOP allocation phase, the sharing AP may share a portion(s) of its TXOP with the selected candidate shared AP(s). The selected candidate shared AP(s) may then use their respective allocated portions of the TXOP to transmit and receive traffic with their associated non-AP stations (STAs).

[0032] For the sharing AP to appropriately select the candidate shared AP(s) that should participate in the c-TDMA (e.g., select candidate shared AP(s) in a manner that satisfies quality of service (QoS) requirements), the sharing AP should know the current situations of the candidate shared APs. An initial control response frame format is described herein for providing information that the sharing AP can use to select the appropriate candidate shared AP(s) that should participate in c-TDMA.

[0033] According to some embodiments, the sharing AP transmits an initial control frame to poll candidate shared APs regarding participating in c-TDMA. A candidate shared AP that receives the initial control frame may transmit an initial control response frame to the sharing AP. The initial control response frame may comprise a multi-station block acknowledgement frame that includes a block acknowledgement bitmap field that is repurposed to carry information regarding a willingness of the candidate shared AP to participate in c-TDMA. The information carried in the block acknowledgement bitmap field may include an indication that the candidate shared AP wishes to participate in c-TDMA, traffic characteristic information of traffic that the candidate shared AP wishes to process in a basic service set (BSS) operated by the candidate shared AP during the c-TDMA, information regarding an estimated processing time or expiry time for traffic that the candidate shared AP wishes to process in the BSS operated by the candidate shared AP during the c-TDMA, information regarding an allowable delay for traffic that the candidate shared AP wishes to process in the BSS during the c-TDMA, dynamic unavailability operation (DUO) information regarding when the candidate shared AP is unavailable, or any combination thereof. The sharing AP may receive a multi-station block acknowledgement frame from each of one or more candidate shared APs as a response to the initial control frame. The sharing AP may extract the information from the repurposed block acknowledgement bitmap fields included in the multi-station block acknowledgement frames received from the one or more candidate shared APs and select one or more of the one or more candidate shared APs to participate in the c-TDMA based on the information extracted from the Docket No. 1002P25009W01Client Matter No. P25-009W01repurposed block acknowledgement bitmap fields. The sharing AP may then share a TXOP owned by the sharing AP with the selected one or more candidate shared APs.

[0034] The initial control response frame format (e.g., the multi-station block acknowledgement frame format) described herein allows candidate shared APs to provide information to the sharing AP that the sharing AP can use to make appropriate decisions regarding which candidate shared AP(s) should participate in c-TDMA and how to schedule the candidate shared AP(s) (e.g., which portion(s) of the TXOP to share with which candidate shared AP(s)). For example, the sharing AP may prioritize candidate shared AP(s) that have low latency (LL) traffic or traffic associated with a particular access category (AC) to process when selecting the final shared AP(s) that are to participate in c-TDMA. This allows the sharing AP to schedule the c-TDMA more effectively (e.g., in a manner that satisfies QoS requirements and utilizes channel resources efficiently).

[0035] For purposes of illustration, various embodiments are described herein in the context of wireless networks that are based on IEEE 802.11 standards and using terminology and concepts thereof. Those skilled in the art will appreciate that the embodiments disclosed herein can be modified / adapted for use in other types of wireless networks.

[0036] In the following detailed description, only certain embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

[0037] Figure 1 shows a wireless local area network (WLAN) 100 with a basic service set (BSS) 102 that includes a plurality of wireless devices 104 (sometimes referred to as WLAN devices 104). Each of the wireless devices 104 may include a medium access control (MAC) layer and a physical (PHY) layer according to an IEEE (Institute of Electrical and Electronics Engineers) standard 802.11, including one or more of the amendments(e.g., 802.1 la / b / g / n / p / ac / ax / bd / be). In one embodiment, the MAC layer of a wireless device 104 may initiate transmission of a frame to another wireless device 104 by passing a PHY-TXSTART. request (TXVECTOR) to the PHY layer. The TXVECTOR provides parameters for generating and / or transmitting a corresponding frame. Similarly, a PHY layer of a receiving wireless device may generate an RXVECTOR, which includes parameters of a received frame and is passed to a MAC layer for processing.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0038] The plurality of wireless devices 104 may include a wireless device 104A that is an access point (sometimes referred to as an AP station or AP STA) and the other wireless devices 104B1-104B4 that are non-AP stations (sometimes referred to as non-AP STAs).Alternatively, all the plurality of wireless devices 104 may be non-AP STAs in an ad-hoc networking environment. In general, the AP STA (e.g., wireless device 104A) and the non-AP STAs (e.g., wireless devices 104B1-104B4) may be collectively referred to as STAs. However, for ease of description, only the non-AP STAs may be referred to as STAs unless the context indicates otherwise. Although shown with four non-AP STAs (e.g., the wireless devices 104B1-104B4), the WLAN 100 may include any number of non-AP STAs (e.g., one or more wireless devices 104B).

[0039] Figure 2 illustrates a schematic block diagram of a wireless device 104, according to an embodiment. The wireless device 104 may be the wireless device 104 A (i.e., the AP of the WLAN 100) or any of the wireless devices 104B1-104B4 in Figure 1. The wireless device 104 includes a baseband processor 210, a radio frequency (RF) transceiver 240, an antenna unit 250, a storage device (e.g., memory device) 232, one or more input interfaces 234, and one or more output interfaces 236. The baseband processor 210, the storage device 232, the input interfaces 234, the output interfaces 236, and the RF transceiver 240 may communicate with each other via a bus 260.

[0040] The baseband processor 210 performs baseband signal processing and includes a MAC processor 212 and a PHY processor 222. The baseband processor 210 may utilize the memory 232, which may include a non-transitory computer / machine readable medium having software (e.g., computer / machine programing instructions) and data stored therein.

[0041] In an embodiment, the MAC processor 212 includes a MAC software processing unit 214 and a MAC hardware processing unit 216. The MAC software processing unit 214 may implement a first plurality of functions of the MAC layer by executing MAC software, which may be included in the software stored in the storage device 232. The MAC hardware processing unit 216 may implement a second plurality of functions of the MAC layer in specialpurpose hardware. However, the MAC processor 212 is not limited thereto. For example, the MAC processor 212 may be configured to perform the first and second plurality of functions entirely in software or entirely in hardware according to an implementation.

[0042] The PHY processor 222 includes a transmitting (TX) signal processing unit (SPU) 224 and a receiving (RX) SPU 226. The PHY processor 222 implements a plurality of functions of the PHY layer. These functions may be performed in software, hardware, or a combination thereof according to an implementation.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0043] Functions performed by the transmitting SPU 224 may include one or more of Forward Error Correction (FEC) encoding, stream parsing into one or more spatial streams, diversity encoding of the spatial streams into a plurality of space-time streams, spatial mapping of the space-time streams to transmit chains, inverse Fourier Transform (iFT) computation, Cyclic Prefix (CP) insertion to create a Guard Interval (GI), and the like. Functions performed by the receiving SPU 226 may include inverses of the functions performed by the transmittingSPU 224, such as GI removal, Fourier Transform computation, and the like.

[0044] The RF transceiver 240 includes an RF transmitter 242 and an RF receiver 244. The RF transceiver 240 is configured to transmit first information received from the baseband processor 210 to the WLAN 100 (e.g., to another WLAN device 104 of the WLAN 100) and provide second information received from the WLAN 100 (e.g., from another WLAN device 104 of the WLAN 100) to the baseband processor 210.

[0045] The antenna unit 250 includes one or more antennas. When Multiple-Input Multiple-Output (MIMO) or Multi-User MIMO (MU-MIMO) is used, the antenna unit 250 may include a plurality of antennas. In an embodiment, the antennas in the antenna unit 250 may operate as a beam-formed antenna array. In an embodiment, the antennas in the antenna unit 250 may be directional antennas, which may be fixed or steerable.

[0046] The input interfaces 234 receive information from a user, and the output interfaces 236 output information to the user. The input interfaces 234 may include one or more of a keyboard, keypad, mouse, touchscreen, microphone, and the like. The output interfaces 236 may include one or more of a display device, touch screen, speaker, and the like.

[0047] As described herein, many functions of the WLAN device 104 may be implemented in either hardware or software. Which functions are implemented in software and which functions are implemented in hardware will vary according to constraints imposed on a design. The constraints may include one or more of design cost, manufacturing cost, time to market, power consumption, available semiconductor technology, etc.

[0048] As described herein, a wide variety of electronic devices, circuits, firmware, software, and combinations thereof may be used to implement the functions of the components of the WLAN device 104. Furthermore, the WLAN device 104 may include other components, such as application processors, storage interfaces, clock generator circuits, power supply circuits, and the like, which have been omitted in the interest of brevity.

[0049] Figure 3 A illustrates components of a WLAN device 104 configured to transmit data according to an embodiment, including a transmitting (Tx) SPU (TxSP) 324, an RF transmitter 342, and an antenna 352. In an embodiment, the TxSP 324, the RF transmitter 342, Docket No. 1002P25009W01Client Matter No. P25-009W01and the antenna 352 correspond to the transmitting SPU 224, the RF transmitter 242, and an antenna of the antenna unit 250 of Figure 2, respectively.

[0050] The TxSP 324 includes an encoder 300, an interleaver 302, a mapper 304, an inverse Fourier transformer (IFT) 306, and a guard interval (GI) inserter 308.

[0051] The encoder 300 receives and encodes input data. In an embodiment, the encoder 300 includes a forward error correction (FEC) encoder. The FEC encoder may include a binary convolution code (BCC) encoder followed by a puncturing device. The FEC encoder may include a low-density parity-check (LDPC) encoder.

[0052] The TxSP 324 may further include a scrambler for scrambling the input data before the encoding is performed by the encoder 300 to reduce the probability of long sequences of 0s or Is. When the encoder 300 performs the BCC encoding, the TxSP 324 may further include an encoder parser for demultiplexing the scrambled bits among a plurality of BCC encoders. If LDPC encoding is used in the encoder, the TxSP 324 may not use the encoder parser.

[0053] The interleaver 302 interleaves the bits of each stream output from the encoder 300 to change an order of bits therein. The interleaver 302 may apply the interleaving only when the encoder 300 performs BCC encoding and otherwise may output the stream output from the encoder 300 without changing the order of the bits therein.

[0054] The mapper 304 maps the sequence of bits output from the interleaver 302 to constellation points. If the encoder 300 performed LDPC encoding, the mapper 304 may also perform LDPC tone mapping in addition to constellation mapping.

[0055] When the TxSP 324 performs a MIMO or MU-MIMO transmission, the TxSP 324 may include a plurality of interleavers 302 and a plurality of mappers 304 according to a number of spatial streams (NSS) of the transmission. The TxSP 324 may further include a stream parser for dividing the output of the encoder 300 into blocks and may respectively send the blocks to different interleavers 302 or mappers 304. The TxSP 324 may further include a space-time block code (STBC) encoder for spreading the constellation points from the spatial streams into a number of space-time streams (NSTS) and a spatial mapper for mapping the space-time streams to transmit chains. The spatial mapper may use direct mapping, spatial expansion, or beamforming.

[0056] The IFT 306 converts a block of the constellation points output from the mapper 304 (or, when MIMO or MU-MIMO is performed, the spatial mapper) to a time domain block (i.e., a symbol) by using an inverse discrete Fourier transform (IDFT) or an inverse fast Fourier transform (IFFT). If the STBC encoder and the spatial mapper are used, the IFT 306 may be provided for each transmit chain.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0057] When the TxSP 324 performs a MIMO or MU-MIMO transmission, the TxSP 324 may insert cyclic shift diversities (CSDs) to prevent unintentional beamforming. The TxSP 324 may perform the insertion of the CSD before or after the IFT 306. The CSD may be specified per transmit chain or may be specified per space-time stream. Alternatively, the CSD may be applied as a part of the spatial mapper.

[0058] When the TxSP 324 performs a MIMO or MU-MIMO transmission, some blocks before the spatial mapper may be provided for each user.

[0059] The GI inserter 308 prepends a GI to each symbol produced by the IFT 306. Each GI may include a Cyclic Prefix (CP) corresponding to a repeated portion of the end of the symbol that the GI precedes. The TxSP 324 may optionally perform windowing to smooth edges of each symbol after inserting the GI.

[0060] The RF transmitter 342 converts the symbols into an RF signal and transmits the RF signal via the antenna 352. When the TxSP 324 performs a MIMO or MU-MIMO transmission, the GI inserter 308 and the RF transmitter 342 may be provided for each transmit chain.

[0061] Figure 3B illustrates components of a WLAN device 104 configured to receive data according to an embodiment, including a Receiver (Rx) SPU (RxSP) 326, an RF receiver 344, and an antenna 354. In an embodiment, the RxSP 326, RF receiver 344, and antenna 354 may correspond to the receiving SPU 226, the RF receiver 244, and an antenna of the antenna unit 250 of Figure 2, respectively.

[0062] The RxSP 326 includes a GI remover 318, a Fourier transformer (FT) 316, a demapper 314, a deinterleaver 312, and a decoder 310.

[0063] The RF receiver 344 receives an RF signal via the antenna 354 and converts the RF signal into symbols. The GI remover 318 removes the GI from each of the symbols. When the received transmission is a MIMO or MU-MIMO transmission, the RF receiver 344 and the GI remover 318 may be provided for each receive chain.

[0064] The FT 316 converts each symbol (that is, each time domain block) into a frequency domain block of constellation points by using a discrete Fourier transform (DFT) or a fast Fourier transform (FFT). The FT 316 may be provided for each receive chain.

[0065] When the received transmission is the MIMO or MU-MIMO transmission, the RxSP 326 may include a spatial demapper for converting the respective outputs of the FTs 316 of the receiver chains to constellation points of a plurality of space-time streams, and an STBC decoder for despreading the constellation points from the space-time streams into one or more spatial streams.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0066] The demapper 314 demaps the constellation points output from the FT 316 or the STBC decoder to bit streams. If the received transmission was encoded using LDPC encoding, the demapper 314 may further perform LDPC tone demapping before performing the constellation demapping.

[0067] The deinterleaver 312 deinterleaves the bits of each stream output from the demapper 314. The deinterleaver 312 may perform the deinterleaving only when the received transmission was encoded using BCC encoding, and otherwise may output the stream output by the demapper 314 without performing deinterleaving.

[0068] When the received transmission is the MIMO or MU-MIMO transmission, the RxSP 326 may use a plurality of demappers 314 and a plurality of deinterleavers 312 corresponding to the number of spatial streams of the transmission. In this case, the RxSP 326 may further include a stream deparser for combining the streams output from the deinterleavers 312.

[0069] The decoder 310 decodes the streams output from the deinterleaver 312 or the stream deparser. In an embodiment, the decoder 310 includes an FEC decoder. The FEC decoder may include a BCC decoder or an LDPC decoder.

[0070] The RxSP 326 may further include a descrambler for descrambling the decoded data. When the decoder 310 performs BCC decoding, the RxSP 326 may further include an encoder deparser for multiplexing the data decoded by a plurality of BCC decoders. When the decoder 310 performs the LDPC decoding, the RxSP 326 may not use the encoder deparser.

[0071] Before making a transmission, wireless devices such as wireless device 104 will assess the availability of the wireless medium using Clear Channel Assessment (CCA). If the medium is occupied, CCA may determine that it is busy, while if the medium is available, CCA determines that it is idle.

[0072] The PHY entity for IEEE 802.11 is based on Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA). In either OFDM or OFDMA Physical (PHY) layers, a STA (e.g., a wireless device 104) is capable of transmitting and receiving Physical Layer (PHY) Protocol Data Units (PPDUs) (also referred to as PLCP (Physical Layer Convergence Procedure) Protocol Data Units) that are compliant with the mandatory PHY specifications. A PHY specification defines a set of Modulation and Coding Schemes (MCS) and a maximum number of spatial streams. Some PHY entities define downlink (DL) and uplink (UL) Multi-User (MU) transmissions having a maximum number of space-time streams (STS) per user and employing up to a predetermined total number of STSs. A PHY entity may provide support for 10 Megahertz (MHz), 20 MHz, 40 MHz, 80 MHz, 160 Docket No. 1002P25009W01Client Matter No. P25-009W01MHz, 240 MHz, and 320 MHz contiguous channel widths and support for an 80+80, 80+160 MHz, and 160+160 MHz non-contiguous channel width. Each channel includes a plurality of subcarriers, which may also be referred to as tones. A PHY entity may define signaling fields denoted as Legacy Signal (L-SIG), Signal A (SIG-A), and Signal B (SIG-B), and the like within a PPDU by which some necessary information about PHY Service Data Unit (PSDU) attributes are communicated. The descriptions below, for sake of completeness and brevity, refer to OFDM-based 802.11 technology. Unless otherwise indicated, a station refers to a non-AP STA.

[0073] Figure 4 illustrates Inter-Frame Space (IFS) relationships. In particular, Figure 4 illustrates a Short IFS (SIFS), a Point Coordination Function (PCF) IFS (PIFS), a Distributed Coordination Function (DCF) IFS (DIFS), and an Arbitration IFSs corresponding to an Access Category (AC) ‘i’ (AIF S [i]). Figure 4 also illustrates a slot time and a data frame is used for transmission of data forwarded to a higher layer. As shown, a WLAN device 104 transmits the data frame after performing backoff if a DIFS has elapsed during which the medium has been idle.

[0074] A management frame may be used for exchanging management information, which is not forwarded to the higher layer. Subtype frames of the management frame include a beacon frame, an association request / response frame, a probe request / response frame, and an authentication request / response frame.

[0075] A control frame may be used for controlling access to the medium. Subtype frames of the control frame include a request to send (RTS) frame, a clear to send (CTS) frame, and an acknowledgement (ACK) frame.

[0076] When the control frame is not a response frame of another frame, the WLAN device 104 transmits the control frame after performing backoff if a DIFS has elapsed during which the medium has been idle. When the control frame is the response frame of another frame, the WLAN device 104 transmits the control frame after a SIFS has elapsed without performing backoff or checking whether the medium is idle.

[0077] A WLAN device 104 that supports Quality of Service (QoS) functionality (that is, a QoS STA) may transmit the frame after performing backoff if an AIFS for an associated access category (AC) (i.e., AIFS[AC]) has elapsed. When transmitted by the QoS STA, any of the data frame, the management frame, and the control frame, which is not the response frame, may use the AIFS [AC] of the AC of the transmitted frame.

[0078] A WLAN device 104 may perform a backoff procedure when the WLAN device 104 that is ready to transfer a frame finds the medium busy. The backoff procedure includes determining a random backoff time composed of N backoff slots, where each backoff slot has a Docket No. 1002P25009W01Client Matter No. P25-009W01duration equal to a slot time and N being an integer number greater than or equal to zero. The backoff time may be determined according to a length of a Contention Window (CW). In an embodiment, the backoff time may be determined according to an AC of the frame. All backoff slots occur following a DIFS or Extended IFS (EIFS) period during which the medium is determined to be idle for the duration of the period.

[0079] When the WLAN device 104 detects no medium activity for the duration of a particular backoff slot, the backoff procedure shall decrement the backoff time by the slot time. When the WLAN device 104 determines that the medium is busy during a backoff slot, the backoff procedure is suspended until the medium is again determined to be idle for the duration of a DIFS or EIFS period. The WLAN device 104 may perform transmission or retransmission of the frame when the backoff timer reaches zero.

[0080] The backoff procedure operates so that when multiple WLAN devices 104 are deferring and execute the backoff procedure, each WLAN device 104 may select a backoff time using a random function and the WLAN device 104 that selects the smallest backoff time may win the contention, reducing the probability of a collision.

[0081] Figure 5 illustrates a Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) based frame transmission procedure for avoiding collision between frames in a channel according to an embodiment. Figure 5 shows a first station STA1 transmitting data, a second station STA2 receiving the data, and a third station STA3 that may be located in an area where a frame transmitted from the STA1 can be received, a frame transmitted from the second station STA2 can be received, or both can be received. The stations STA1, STA2, and STA3 may be WLAN devices 104 of Figure 1.

[0082] The station STA1 may determine whether the channel is busy by carrier sensing. The station STA1 may determine channel occupation / status based on an energy level in the channel or an autocorrelation of signals in the channel, or may determine the channel occupation by using a network allocation vector (NAV) timer.

[0083] After determining that the channel is not used by other devices (that is, that the channel is IDLE) during a DIFS (and performing backoff if required), the station STA1 may transmit a Request-To-Send (RTS) frame to the station STA2. Upon receiving the RTS frame, after a SIFS the station STA2 may transmit a Clear-To-Send (CTS) frame as a response to the RTS frame. If Dual-CTS is enabled and the station STA2 is an AP, the AP may send two CTS frames in response to the RTS frame (e.g., a first CTS frame in a non-High Throughput format and a second CTS frame in the HT format).Docket No. 1002P25009W01Client Matter No. P25-009W01

[0084] When the station STA3 receives the RTS frame, it may set a NAV timer of the station STA3 for a transmission duration of subsequently transmitted frames (for example, a duration of SIFS + CTS frame duration + SIFS + data frame duration + SIFS + ACK frame duration) using duration information included in the RTS frame. When the station STA3 receives the CTS frame, it may set the NAV timer of the station STA3 for a transmission duration of subsequently transmitted frames using duration information included in the CTS frame. Upon receiving a new frame before the NAV timer expires, the station STA3 may update the NAV timer of the station STA3 by using duration information included in the new frame. The station STA3 does not attempt to access the channel until the NAV timer expires.

[0085] When the station STA1 receives the CTS frame from the station STA2, it may transmit a data frame to the station STA2 after a SIFS period elapses from a time when the CTS frame has been completely received. Upon successfully receiving the data frame, the station STA2 may transmit an ACK frame as a response to the data frame after a SIFS period elapses.

[0086] When the NAV timer expires, the third station STA3 may determine whether the channel is busy using the carrier sensing. Upon determining that the channel is not used by other devices during a DIFS period after the NAV timer has expired, the station STA3 may attempt to access the channel after a contention window elapses according to a backoff process.

[0087] When Dual-CTS is enabled, a station that has obtained a transmission opportunity (TXOP) and that has no data to transmit may transmit a CF-End frame to cut short the TXOP. An AP receiving a CF-End frame having a Basic Service Set Identifier (BSSID) of the AP as a destination address may respond by transmitting two more CF-End frames: a first CF-End frame using Space Time Block Coding (STBC) and a second CF-End frame using non-STBC. A station receiving a CF-End frame resets its NAV timer to 0 at the end of the PPDU containing the CF-End frame. Figure 5 shows the station STA2 transmitting an ACK frame to acknowledge the successful reception of a frame by the recipient.

[0088] The IEEE 802.1 Ibn (Ultra High Reliability, UHR) working group has been established to address the growing demand for higher peak throughput and reliability in Wi-Fi. As shown in Figure 6, the peak PHY rate has significantly increased from IEEE 802.1 lb to IEEE 802.1 Ibe (Wi-Fi 7), with the latter focusing on further improving peak throughput. The UHR study group aims to enhance the tail of the latency distribution and jitter to support applications that require low latency, such as video-over- WLAN, gaming, AR, and VR. It is noted that various characteristics of UHR (e.g., max PHY rate, PHY rate enhancement, bandwidth / number of spatial streams, and operating bands) are still to be determined.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0089] The focus of IEEE 802.1 Ibe is primarily on WLAN indoor and outdoor operation with stationary and pedestrian speeds in the 2.4, 5, and 6 GHz frequency bands. In addition to peak PHY rate, different candidate features are under discussion. These candidate features include (1) a 320MHz bandwidth and a more efficient utilization of a non-contiguous spectrum, (2) multi -band / multi-channel aggregation and operation, (3) 16 spatial streams and Multiple Input Multiple Output (MIMO) protocol enhancements, (4) multi-Access Point (AP) Coordination (e.g., coordinated and joint transmission), (5) an enhanced link adaptation and retransmission protocol (e.g., Hybrid Automatic Repeat Request (HARQ)), and (6) adaptation to regulatory rules specific to a 6 GHz spectrum.

[0090] The focus of IEEE 802.1 Ibn (UHR) is still under discussion, with candidate features including MLO enhancements (e.g., in terms of increased throughput / reliability and decreased latency), latency and reliability improvements (e.g., multi-AP coordination to support low latency traffic), bandwidth expansion (e.g., to 240, 480, 640 MHz), aggregated PPDU (A-PPDU), enhanced multi-link single-radio (eMLSR) extensions to AP, roaming improvements, and power-saving schemes for prolonging battery life.

[0091] Some features, such as increasing the bandwidth and the number of spatial streams, are solutions that have been proven to be effective in previous projects focused on increasing link throughput and on which feasibility demonstration is achievable.

[0092] With respect to operational bands (e.g., 2.4 / 5 / 6 GHz) for IEEE 802.1 Ibe, more than 1 GHz of additional unlicensed spectrum is likely to be available because the 6 GHzband (5.925- 7.125 GHz) is being considered for unlicensed use. This would allow APs and STAs to become tri -band devices. Larger than 160MHz data transmissions (e.g., 320 MHz or 640 MHz) could be considered to increase the maximum PHY rate. For example, 320 MHz or 160+160MHz data could be transmitted in the 6 GHz band. For example, 160+160 MHz data could be transmitted across the 5 and 6 GHz bands.

[0093] In the process of wireless communication, a transmitting station (STA) creates a Physical Layer Protocol Data Unit (PPDU) frame and sends it to a receiving STA. The receiving STA then receives, detects, and processes the PPDU.

[0094] The Extremely High Throughput (EHT) PPDU frame encompasses several components. It includes a legacy part, which comprises fields such as the Legacy Short Training Field (L-STF), Legacy Long Training Field (L-LTF), Legacy Signal Field (L-SIG), and Repeated Legacy Signal Field (RL-SIG). These fields are used to maintain compatibility with older Wi-Fi standards.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0095] In addition to the legacy part, the EHT PPDU frame also contains the Universal Signal Field (U-SIG), EHT Signal Field (EHT-SIG), EHT Short Training Field (EHT-STF), and EHT Long Training Field (EHT-LTF). These fields are specific to the EHT standard and are used for various purposes, such as signaling, synchronization, and channel estimation.

[0096] Figure 7 provides a more detailed description of each field in the EHT PPDU frame, including their purposes and characteristics.

[0097] Regarding the Ultra High Reliability (UHR) PPDU, its frame structure is currently undefined and will be determined through further discussions within the relevant working group or study group. This indicates that the specifics of the UHR PPDU are still under development and will be finalized based on the outcomes of future deliberations.

[0098] The distributed nature of channel access networks, such as IEEE 802.11 WLANs, makes the carrier sense mechanism useful for ensuring collision-free operation. Each station (STA) uses its physical carrier sense to detect transmissions from other STAs. However, in certain situations, it may not be possible for a STA to detect every transmission. For instance, when one STA is located far away from another STA, it might perceive the medium as idle and start transmitting a frame, leading to collisions. To mitigate this hidden node problem, the network allocation vector (NAV) has been introduced.

[0099] As the IEEE 802.11 standard continues to evolve, it now includes scenarios where multiple users can simultaneously transmit or receive data within a basic service set (BSS), such as uplink (UL) and downlink (DL) multi-user (MU) transmissions in a cascaded manner. In these cases, the existing carrier sense and NAV mechanisms may not be sufficient, and modifications or newly defined mechanisms may be required to facilitate efficient and collision-free operation.

[0100] For the purpose of this disclosure, MU transmission refers to situations where multiple frames are transmitted to or from multiple STAs simultaneously using different resources. Examples of these resources include different frequency resources in Orthogonal Frequency Division Multiple Access (OFDMA) transmission and different spatial streams in Multi-User Multiple Input Multiple Output (MU-MIMO) transmission. Consequently, downlink OFDMA (DL-OFDMA), downlink MU-MIMO (DL-MU-MIMO), uplink OFDMA (UL-OFDMA), uplink MU-MIMO (UL-MU-MIMO), and OFDMA with MU-MIMO are all considered examples of MU transmission.

[0101] Figure 8 illustrates an example of multi-user (MU) transmission in Orthogonal Frequency-Division Multiple Access (OFDMA), in accordance with some embodiments of the present disclosure.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0102] In the IEEE 802.1 lax and 802.1 Ibe specifications, the trigger frame plays a useful role in facilitating uplink multi-user (MU) transmissions. The purpose of the trigger frame is to allocate resources and solicit one or more Trigger-based (TB) Physical Layer Protocol Data Unit (PPDU) transmissions from the associated stations (STAs).

[0103] The trigger frame contains information required by the responding STAs to send their Uplink TB PPDUs. This information includes the Trigger type, which specifies the type of TB PPDU expected, and the Uplink Length (UL Length), which indicates the duration of the uplink transmission.

[0104] Figure 9 illustrates an example scenario where an access point (AP) operating in an 80MHz bandwidth environment sends a Trigger frame to multiple associated STAs. Upon receiving the Trigger frame, the STAs respond by sending their respective Uplink Orthogonal Frequency Division Multiple Access (UL OFDMA) TB PPDUs, utilizing the allocated resources within the specified 80 MHz bandwidth.

[0105] After successfully receiving the UL OFDMA TB PPDUs, the AP acknowledges the STAs by sending an acknowledgement frame. This acknowledgement can be in the form of an 80MHz width multi-STA Block Acknowledgement (Block Ack) or a Block Acknowledgement with a Direct Feedback (DF) OFDMA method. The multi-STA Block Ack allows the AP to acknowledge multiple STAs simultaneously, while the Block Ack with DF OFDMA enables the AP to provide feedback to the STAs using the same OFDMA technique employed in the uplink transmission.

[0106] The trigger frame is a useful component in enabling efficient uplink MU transmissions in IEEE 802.1 lax and 802.1 Ibe networks, by allocating resources and coordinating the uplink transmissions from multiple STAs within the same bandwidth.

[0107] Wireless network systems can rely on retransmission of media access control (MAC) protocol data units (MPDUs) when the transmitter (TX) does not receive an acknowledgement from the receiver (RX) or MPDUs are not successfully decoded by the receiver. Using an automatic repeat request (ARQ) approach, the receiver discards the last failed MPDU before receiving the newly retransmitted MPDU. With requirements of enhanced reliability and reduced latency, the wireless network system can evolve toward a hybrid ARQ (HARQ) approach.

[0108] There are two methods of HARQ processing. In a first type of HARQ scheme, also referred to as chase combining (CC) HARQ (CC-HARQ) scheme, signals to be retransmitted are the same as the signals that previously failed because all subpackets to be retransmitted use the same puncturing pattern. The puncturing is needed to remove some of the parity bits after Docket No. 1002P25009W01Client Matter No. P25-009W01encoding using an error-correction code. The reason why the same puncturing pattern is used with CC-HARQ is to generate a coded data sequence with forward error correction (FEC) and to make the receiver use a maximum-ratio combining (MRC) to combine the received, retransmitted bits with the same bits from the previous transmission. For example, information sequences are transmitted in packets with a fixed length. At a receiver, error correction and detection are carried out over the whole packet. However, the ARQ scheme may be inefficient in the presence of burst errors. To solve this more efficiently, subpackets are used. In subpacket transmissions, only those subpackets that include errors need to be retransmitted.

[0109] Since the receiver uses both the current and the previously received subpackets for decoding data, the error probability in decoding decreases as the number of used subpackets increases. The decoding process passes a cyclic redundancy check (CRC) and ends when the entire packet is decoded without error or the maximum number of subpackets is reached. In particular, this scheme operates on a stop-and-wait protocol such that if the receiver can decode the packet, it sends an acknowledgement (ACK) to the transmitter. When the transmitter receives an ACK successfully, it terminates the HARQ transmission of the packet. If the receiver cannot decode the packet, it sends a negative acknowledgement (NAK) to the transmitter and the transmitter performs the retransmission process.

[0110] In a second type of HARQ scheme, also referred to as an incremental redundancy (IR) HARQ (IR-HARQ) scheme, different puncturing patterns are used for each subpacket such that the signal changes for each retransmitted subpacket in comparison to the originally transmitted subpacket. IR-HARQ alternatively uses two puncturing patterns for odd numbered and even numbered transmissions, respectively. The redundancy scheme of IR-HARQ improves the log likelihood ratio (LLR) of parity bit(s) in order to combine information sent across different transmissions due to requests and lowers the code rate as the additional subpacket is used. This results in a lower error rate of the subpacket in comparison to CC-HARQ. The puncturing pattern used in IR-HARQ is indicated by a subpacket identity (SPID) indication. The SPID of the first subpacket may always be set to 0 and all the systematic bits and the punctured parity bits are transmitted in the first subpacket. Self-decoding is possible when the receiving signal-to-noise ratio (SNR) environment is good (i.e., a high SNR). In some embodiments, subpackets with corresponding SPIDs to be transmitted are in increasing order of SPID but can be exchanged / switched except for the first SPID.

[0111] AP coordination has been considered as a potential technology to improve WLAN system throughput in the IEEE 802.1 Ibe standard and is still being discussed in theIEEE 802.1 Ibn (UHR) standard. To support various AP coordination schemes, such as Docket No. 1002P25009W01Client Matter No. P25-009W01coordinated beamforming, OFDMA, TDMA, spatial reuse, and joint transmission, a predefined mechanism for APs is necessary.

[0112] In the context of coordinated TDMA (C-TDMA), the AP that obtains a transmit opportunity (TXOP) is referred to as the sharing AP. This AP initiates the AP coordination schemes to determine the AP candidate set by sending a frame, such as a Beacon frame or probe response frame, which includes information about the AP coordination scheme capabilities. The AP that participates in the AP coordination schemes after receiving the frame from the sharing AP is called the shared AP. The sharing AP is also known as the master AP or coordinating AP, while the shared AP is referred to as the slave AP or coordinated AP.

[0113] The operation of various AP coordination schemes has been discussed in the IEEE 802.1 Ibe and UHR standards:

[0114] Coordinated Beamforming (C-BF): Multiple APs transmit on the same frequency resource by coordinating and forming spatial nulls, allowing for simultaneous transmission from multiple APs.

[0115] Coordinated OFDMA (C-OFDMA): APs transmit on orthogonal frequency resources by coordinating and splitting the spectrum, enabling more efficient spectrum utilization.

[0116] Joint Transmission (JTX): Multiple APs transmit jointly to a given user simultaneously by sharing data between the APs.

[0117] Coordinated Spatial Reuse (C-SR): Multiple APs or STAs adjust their transmit power to reduce interference between APs.

[0118] By implementing these AP coordination schemes, WLAN systems can improve their overall throughput and efficiency by leveraging the cooperation between multiple APs.

[0119] C-TDMA (or c-TDMA) is a multi-AP coordination scheme that allows APs to share their TXOPs with other APs. For example, assume a scenario where a first AP (API) and a second AP (AP2) each operate their own BSS. API may occupy the channel and become the TXOP owner. API may then allocate a portion of the TXOP it owns to AP2 through c-TDMA, allowing AP2 to transmit and receive in AP2’s its BSS even though AP2 is not the original TXOP owner.

[0120] During a polling phase (prior to allocating a portion of its TXOP to a shared AP), the sharing AP may transmit an initial control frame to candidate shared AP(s). The candidate shared AP(s) may be candidate(s) to be the final shared AP(s) for c-TDMA. The initial control frame may serve the role of polling the candidate shared AP(s) regarding their interest in participating in c-TDMA. The candidate shared AP(s) that are interested in participating in c-TDMA may respond to the initial control frame by transmitting an initial control response frame Docket No. 1002P25009W01Client Matter No. P25-009W01(ICR). Through the initial control frame and initial control response frame exchange, the sharing AP may be able to obtain information that can help it decide which candidate shared AP(s) should be selected as the final shared AP(s) for TXOP sharing. If multiple candidate shared APs are selected to be the final shared APs, the sharing AP may sequentially share portions of its TXOP with the selected candidate shared APs.

[0121] Figure 10 is a diagram showing a frame exchange sequence where the sharing AP polls a candidate shared AP regarding its interest in participating in c-TDMA, selects the candidate shared AP to be the final shared AP for c-TDMA, and shares the TXOP with the candidate shared AP, according to some embodiments.

[0122] The example shown in the diagram is an example where the sharing AP polls a single candidate shared AP regarding its interest in participating in the c-TDMA and selects this single candidate shared AP to be the final shared AP to participate in c-TDMA.

[0123] As shown in the diagram, the sharing AP may transmit initial control frame 1005 to the candidate shared AP. In response to receiving initial control frame 1005, the candidate shared AP may transmit response frame 1010 (an initial control response frame or ICR) to the sharing AP as a response to initial control frame 1005. The sharing AP may then select the candidate shared AP to participate in the c-TDMA (e.g., because the candidate shared AP’s response may indicate that it is interested in participating in c-TDMA).

[0124] Before allocating a portion of its TXOP to the selected candidate shared AP, the sharing AP may use the TXOP to perform frame exchange 1015 with its in-BSS non-AP STAs (STAs that are associated with the sharing AP).

[0125] After performing frame exchange 1015, the sharing AP may transmit control frame 1020 to the candidate shared AP to share a portion of its TXOP with the candidate (selected) shared AP. In an embodiment, control frame 1020 is a multi-user request-to-send transmission opportunity sharing (MU-RTS TXS) frame. Responsive to receiving control frame 1020, the candidate shared AP may transmit response frame 1025 to the sharing AP. In an embodiment, response frame 1025 is a clear-to-send (CTS) frame. As a result, the candidate shared AP becomes the final shared AP. During the portion of the TXOP allocated to the candidate shared AP (depicted as “Time shared by sharing AP” in the diagram), the candidate shared AP may transmit data frame 1030 to a STA that is associated with the candidate shared AP. Responsive to receiving data frame 1030, the STA associated with the candidate shared AP may transmit BA frame 1035 to the candidate shared AP.

[0126] To perform efficient c-TDMA, the sharing AP (which is the original TXOP owner) needs to decide which candidate shared APs should participate in c-TDMA (i.e., which Docket No. 1002P25009W01Client Matter No. P25-009W01candidate shared APs should be allocated a portion of the sharing AP’s TXOP). This process may be referred to as the polling phase in the c-TDMA procedure. During the polling phase, the sharing AP may transmit an initial control frame to indicate its intention to share the TXOP it has obtained and to poll candidate shared APs regarding their interest in participating in c-TDMA. A candidate shared AP that receives the initial control frame may respond by transmitting an initial control response frame to indicate its interest in participating in c-TDMA (to indicate that the candidate shared AP wishes to use the TXOP).

[0127] In some cases, the sharing AP may not receive a response to the initial control frame from a candidate shared AP (e.g., not receive an initial control response frame) during the polling phase. This may be because the shared AP is not interested in participating in c-TDMA. If the sharing AP does not receive a response to the initial control frame from a candidate shared AP, the sharing AP may infer that the candidate shared AP is not interested in participating in c-TDMA.

[0128] Figure 11 is a diagram showing a frame exchange sequence where the sharing AP transmits an initial control frame to multiple candidate shared APs and only one of the candidate shared APs respond to the initial control frame and participates in c-TDMA, according to some embodiments.

[0129] As shown in the diagram, during a polling phase, the sharing AP may transmit initial control frame 1105 to a first candidate shared AP (candidate shared AP #1) and a second candidate shared AP (candidate shared AP #2), but only candidate shared AP #1 may transmit response frame 1110. In this example, candidate shared AP #2 does not respond to initial control frame 1105. The sharing AP may from the lack of response that candidate shared AP #2 is not interested in participating in c-TDMA. Thus, in this example, the sharing AP may select candidate shared AP #1 to participate in c-TDMA and candidate shared AP #1 becomes the final shared AP.

[0130] Before allocating a portion of its TXOP to the candidate shared AP #1, the sharing AP may use the TXOP to perform frame exchange 1115 with its in-BSS non-AP STAs (STAs that are associated with the sharing AP).

[0131] After performing frame exchange 1115, the sharing AP may transmit control frame 1120 to candidate shared AP #1 to share a portion of its TXOP with candidate shared AP #1. In an embodiment, control frame 1120 is a MU-RTS TXS frame. Responsive to receiving control frame 1120, candidate shared AP #1 may transmit response frame 1125 to the sharing AP. In an embodiment, response frame 1125 is a CTS frame. As a result, candidate shared AP #1 becomes the final shared AP in this example. During the portion of the TXOP Docket No. 1002P25009W01Client Matter No. P25-009W01allocated to candidate shared AP #1 (depicted as “Time shared by sharing AP” in the diagram), candidate shared AP #1 may transmit data frame 1130 to a STA that is associated with candidate shared AP #1. Responsive to receiving data frame 1130, the STA associated with candidate shared AP #1 may transmit BA frame 1135 to candidate shared AP #1.

[0132] The initial control frame that is transmitted during the polling phase of c-TDMA may be a trigger frame such as a buffer status report poll (BSRP) trigger frame. The initial control response frame that is transmitted as a response to the initial control frame during the polling phase of c-TDMA may be a multi-station block acknowledgement (multi-STA BA or M-BA) frame. The present disclosure discloses a multi-STA BA frame format (which is a candidate for being used as an initial control response frame) to provide information that a sharing AP can use to perform efficient c-TDMA. The information may allow the sharing AP to select the candidate shared AP(s) that should participate in c-TDMA in a manner that satisfies QoS requirements and utilizes channel resources efficiently.

[0133] When the sharing AP transmits an initial control frame (e.g., a BSRP trigger frame) to the candidate shared AP, it may include traffic characteristic information or TXOP information in the initial control frame.

[0134] The traffic characteristic information included in the initial control frame may include access category (AC) information, stream classification service identifier (SCSID) information, and / or traffic identifier (TID) information. Including such information in the initial control frame may indicate to the candidate shared AP that the candidate shared AP is only allowed to participate in c-TDMA if it has traffic to process (e.g., traffic that is already queued or periodic traffic that is expected to arrive in the future) having the indicated traffic characteristics or higher priority traffic. Thus, upon receiving an initial control frame that includes traffic characteristic information, the candidate shared AP may respond by transmitting an initial control response frame to express its interest in participating in the C-TDMA if the conditions are met.

[0135] In an embodiment, the initial control response frame includes a simple indication of the candidate shared AP’s interest in participating in c-TDMA (this is referred to as solution #1 herein). In an embodiment, in addition to including the indication of the candidate shared AP’s interest in participating in c-TDMA, the initial control response frame also includes traffic characteristic information (AC / SCSID / TID information) of the traffic that the candidate shared AP wishes to process in its own BSS (this is referred to as solution #2 herein) during c-TDMA. In an embodiment, the initial control response frame includes traffic characteristic information of the traffic that the candidate shared AP wishes to process in its own BSS, without including Docket No. 1002P25009W01Client Matter No. P25-009W01an indication that the candidate shared AP is interested in participating in c-TDMA. The inclusion of the traffic characteristic information can be inferred as an indication that the candidate shared AP is interested in participating in c-TDMA (this is referred to as solution #3 herein).

[0136] The TXOP information included in the initial control frame may have one of two meanings. The first meaning is that the sharing AP is willing to share the entire TXOP it has obtained (this is referred to as case #1 herein). The second meaning is that the sharing AP is willing to share a portion of the TXOP it has obtained (this is referred to as case #2 herein).

[0137] In case #1 (the sharing AP is willing to share the entire TXOP it has obtained), the first frame that the sharing AP transmits when it obtains the TXOP is the initial control frame and this initial control frame may include the TXOP limit corresponding to the AC (or other traffic category) at the time of TXOP acquisition.

[0138] Upon receiving the initial control frame that includes such TXOP information, a candidate shared AP may respond by transmitting an initial control response frame that indicates whether it has low latency (LL) traffic to process during the TXOP window specified in the initial control frame. The indication of whether low latency traffic exists can be encoded using a single bit. For example, if low latency traffic does not exist, the single bit may be set to a value of binary “0”, otherwise the single bit may be set to a value of binary “1”. Upon receiving the initial control response frame, the sharing AP may decide to exclude a candidate shared AP from the final list of shared APs for c-TDMA participation if the initial control frame received from the candidate shared AP includes an indication that the candidate shared AP does not have low latency traffic to process.

[0139] If a candidate shared AP does not have low latency traffic to process, the candidate shared AP may choose not to respond to the initial control frame (e.g., not transmit an initial control response frame) to implicitly indicate that it is not interested in participating in c-TDMA. If the sharing AP does not receive a response to the initial control frame from the candidate shared AP, the sharing AP may infer that the candidate shared AP intentionally did not respond (because the candidate shared AP is not interested in participating in c-TDMA) and exclude the candidate shared AP from the final list of shared APs for c-TDMA participation.

[0140] In an embodiment, the initial control response frame transmitted by a candidate shared AP may include information regarding the candidate shared AP's in-device coexistence (IDC) issues. This information may help the sharing AP when scheduling shared APs for c-TDMA. For example, the IDC information may indicate a time period during which the candidate shared AP cannot participate in transmission or reception due to IDC issues. Having such information Docket No. 1002P25009W01Client Matter No. P25-009W01(and possibly combined with other information) can help the sharing AP select the final list of candidate shared AP(s) that should participate in c-TDMA. Alternatively, the sharing AP may adjust the expected c-TDMA allocation period to avoid overlap with the candidate shared AP's IDC interference issues. If the candidate shared AP cannot function properly due to IDC issues, it may be a waste of resources to include it in the c-TDMA process. Thus, such waste / inefficiency can be avoided in advance if the sharing AP has IDC information.

[0141] For example, a candidate shared AP may have an IDC issue with technologies such as Bluetooth during a specific time period, making Wi-Fi transmission and reception impossible. In this case, even if the candidate shared AP is allowed to participate in c-TDMA, it will not be able to transmit or receive. Thus, to avoid such a scenario, the candidate shared AP may respond to the initial control frame by considering its unavailability due to IDC issues during the TXOP. For example, if the candidate shared AP expects IDC issues during the TXOP, the candidate shared AP may choose not to respond to the initial control frame. In another embodiment, the candidate shared AP may transmit an initial control response frame to the sharing AP that includes information regarding when the candidate shared AP will be unavailable due to IDC issues, which allows the sharing AP to determine whether to include the candidate shared AP in the c-TDMA process or not.

[0142] In an embodiment, the initial control response frame includes timing information related to IDC unavailability (e.g., dynamic unavailability operation (DUO) information), information regarding periodic low latency traffic, information regarding estimated traffic processing times, and / or information regarding maximum allowable delays (this is referred to as solution #4 herein).

[0143] In case #2 (the sharing AP is willing to share a portion of the TXOP it has obtained), the sharing AP may transmit the expected portion of the TXOP to be allocated for in-BSS STAs and / or the expected portion of the TXOP to be allocated for c-TDMA immediately upon TXOP acquisition or during the TXOP period via an initial control frame.

[0144] In an embodiment, when informing the candidate shared AP of the expected portion of the TXOP allocated for in-BSS STAs and / or c-TDMA usage, the sharing AP may consider its own IDC issues. For example, if the duration of the portion of the TXOP allocated for in-BSS STAs and c-TDMA usage is denoted as @, this portion can be within the TXOP acquired by the sharing AP, from time t to t+@ and from time q to q+@. If the t to t+@ time period is affected by IDC issues, the sharing AP may plan to allocate the q to q+@ time period of the TXOP. In this case, the sharing AP can indicate the q time and @ duration in the initial control frame. If the sharing AP does not have IDC issues, it may implicitly indicate that there are no IDC issues Docket No. 1002P25009W01Client Matter No. P25-009W01by transmitting the initial control frame at time q with an indication of the @ duration. Upon receiving the initial control frame including such TXOP information, the candidate shared AP may respond by transmitting an initial control response frame with information similar to the information mentioned above for case #1 (e.g., low latency traffic indication, unavailability information, information regarding estimated traffic processing times, information regarding maximum allowable delays, etc.).

[0145] Example initial control response frame formats for providing feedback information of solutions #1-4 are now described. It is assumed in these examples that the initial control response frame is a multi-STA BA frame. For context, the basic format of a multi-STA BA frame is first described.

[0146] Figure 12 is a diagram showing a multi-STA BA frame format, according to some embodiments.

[0147] As shown in the diagram, the multi-STA BA frame may include a frame control field 1205 (2 octets), a duration field 1210 (2 octets), a receiver address (RA) field 1215 (6 octets), a transmitter address (TA) field 1220 (6 octets), a BA control field 1225 (2 octets), a BA information field 1230 (variable length), and a frame check sequence (FCS) field 1235 (4 octets).

[0148] The BA information field 1230 may include one or more per association identifier traffic identifier information (per AID TID info) fields. Each per AID TID info field may include an AID TID info field (2 octets), a block ACK starting sequence control field (0 or 2 octets), and a block ACK bitmap field (0, 4, 8, 12, 16, 32, 64, or 128 octets). For example, as shown in the diagram, the BA information field 1230 may include multiple per AID TID info fields. The first per AID TID info field may include AID TID info field 1240, block ACK starting sequence control field 1245, and block ACK bitmap field 1250. The last per AID TID info field may include AID TID info field 1255, block ACK starting sequence control field 1260, and block ACK bitmap field 1265. The other per AID TID info fields (which are not shown in the diagram) may have a similar format.

[0149] Figure 13 is a diagram showing details of the per AID TID info field format, according to some embodiments.

[0150] As shown in the diagram, the multi-STA BA frame may include a frame control field 1305 (2 octets), a duration field 1310 (2 octets), a RA field 1315 (6 octets), a TA field 1320 (6 octets), a BA control field 1325 (2 octets), a BA information field 1330 (variable length), and a frame check sequence (FCS) field 1335 (4 octets). The BA information field 1330 may include a first per AID TID info field that includes AID TID info field 1340, block ACK starting Docket No. 1002P25009W01Client Matter No. P25-009W01sequence control field 1345, and block ACK bitmap field 1350. The BA information field 1330 may further include a second per AID TID info field that includes AID TID info field 1355, block ACK starting sequence control field 1360, and block ACK bitmap field 1365.

[0151] Also, as shown in the diagram, block ACK starting sequence control field 1345 may include a fragment number field 1370 (4 bits) and a starting sequence number field 1375 (12 bits) Also, the block ACK bitmap field 1350 may include a first reserved (Reservedl) field 1380 (14 bits), a second reserved (Reserved2) field 1385 (9 bits), and a third reserved (Reserved3) field 1390 (9 bits). In this example, the block ACK bitmap field 1350 has a length of 4 octets and is divided into three reserved fields (Reservedl field 1380, Reserved2 field 1385, and Reserved3 field 1390). As will be described in additional detail herein, the three reserved fields may carry information that the sharing AP can use for scheduling c-TDMA when the multi-STA BA frame is used as an initial control frame.

[0152] Figure 14 is a diagram showing a block ACK bitmap field format for providing an indication of a candidate shared AP’s interest in participating in c-TDMA, according to some embodiments.

[0153] The diagram shows an example of solution #1 mentioned above. In this example, the Reservedl field 1380 (of a block ACK bitmap field) may be used for carrying an indication of the candidate shared AP’s interest in participating in c-TDMA. For example, the Reservedl field 1380 may include a participation indicator field 1410 (1 bit) and a reserved field 1420 (13 bits). The participation indicator field 1410 field may carry a value of binary “1” if the candidate shared AP is interested in participating in c-TDMA, but otherwise carry a value of “0” if the candidate shared AP is not interested in participating in c-TDMA.

[0154] Figure 15 is a diagram showing a block ACK bitmap field format for providing an indication of a candidate shared AP’s interest in participating in c-TDMA and traffic characteristic information of traffic that the candidate shared AP wishes to process, according to some embodiments.

[0155] The diagram shows an example of solution #2 mentioned above. In this example, the Reservedl field 1380 (of a block ACK bitmap field) may be used for carrying an indication of the candidate shared AP’s interest in participating in c-TDMA, as well as traffic characteristic information of traffic that the candidate shared AP wishes to process in its BSS during c-TDMA. For example, the Reservedl field 1380 may include a participation indicator field 1510 (1 bit) and an AC / SCSID / TID field 1520 (2 to 13 bits). The participation indicator field 1510 field may carry a value of binary “1” if the candidate shared AP is interested in participating in c-TDMA, but otherwise carry a value of “0” if the candidate shared AP is not interested in Docket No. 1002P25009W01Client Matter No. P25-009W01participating in c-TDMA. The AC / SCSID / TID field 1520 may carry an indication of the AC, SCSID, and / or TID of the traffic that the candidate shared AP wishes to process in its BSS during c-TDMA.

[0156] The number of bits allocated for the AC / SCSID / TID field 1520 can vary. In this example, the length of the AC / SCSID / TID field 1520 can be anywhere between 2 to 13 bits. In an embodiment, the sharing AP can specify the length of the AC / SCSID / TID field 1520 in the initial control frame that the sharing AP transmits to the candidate shared AP.

[0157] Figure 16 is a diagram showing a block ACK bitmap field format for providing traffic characteristic information of traffic that the candidate shared AP wishes to process, according to some embodiments.

[0158] The diagram shows an example of solution #3 mentioned above. In this example, the Reserved 1 field 1380 (of a block ACK bitmap field) may be used for carrying traffic characteristic information of traffic that the candidate shared AP wishes to process in its BSS during the c-TDMA. Although the block ACK bitmap field does not carry an indication that the candidate shared AP is interested in participating in c-TDMA, the presence of the traffic characteristic information may implicitly indicate that the candidate shared AP is interested in participating in c-TDMA.

[0159] For example, the Reservedl field 1380 may include an AC / SCSID / TID field 1610 (1 to 14 bits). The AC / SCSID / TID field 1610 may carry an indication of the AC, SCSID, and / or TID of the traffic that the candidate shared AP wishes to process in its BSS during c-TDMA.

[0160] In this example, the AC / SCSID / TID field 1610 may include one more bit than the AC / SCSID / TID field 1520 for solution #2 (shown in Figure 15) so the length of the AC / SCSID / TID field 1610 may be anywhere between 1 to 14 bits. As with the AC / SCSID / TID field 1520 for solution #2, the number of bits allocated for the AC / SCSID / TID field 1610 can vary.

[0161] Figure 17 is a diagram showing a block ACK bitmap field format for providing information regarding the estimated processing time and information regarding the maximum allowable delay, according to some embodiments.

[0162] The diagram shows an example of solution #4 mentioned above. In this example, the reserved fields can be used for carrying information regarding the estimated processing time for traffic that the candidate shared AP wishes to process during c-TDMA (e.g., the expected time required to transmit and receive buffered data) and / or information regarding the maximum allowable delay for traffic that the candidate shared AP wishes to process during c-TDMA.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0163] For example, the Reserved2 field 1385 may include a processing time of data field 1710 (9 bits) that carries information regarding the estimated processing time. The estimated processing time may be the estimated time to process traffic corresponding to the AC / SCSID / TID indicated in the initial control frame received from the sharing AP. Also, the Reserved3 field 1390 may include an allowable maximum delay of data field 1720 (9 bits) that carries information regarding the maximum allowable delay.

[0164] Multiple candidate shared APs participating in the polling phase may use the reserved fields to provide their respective estimated processing time information and / or maximum tolerable delay information for the traffic they wish to process. This information may help the sharing AP select the appropriate candidate shared APs that should participate in c-TDMA.

[0165] In the example shown in the diagram, the Reserved2 field 1385 and the Resreved3 field 1390 each have a length of 9 bits. It should be appreciated, however, that the length and the bit allocations for these fields can vary depending on the implementation. In an embodiment, the Reservedl field 1380 may be used to carry information (e.g., the information mentioned above for solutions #1-3) in addition to the Reserved2 field 1385 and the Reserved3 field 1390 carrying the estimated processing time information and the allowable delay information.

[0166] Figure 18 is a diagram showing a block ACK bitmap field format for providing DUO information, according to some embodiments.

[0167] The diagram shows another example of solution #4 mentioned above. In an embodiment, if the candidate shared AP has an IDC issue within its own BSS, it may provide information regarding the IDC issue in one or more of the reserved fields. For example, the Reserved2 field 1385 and / or the Reserved3 field 1390 may be used for carrying DUO information.

[0168] For example, as shown in the diagram, the Reserved2 field 1385 may include a start time of unavailability duration field 1810 (9 bits) that carries information regarding the start time of when the candidate shared AP is unavailable. Also, the Reserved3 field 1390 may include an unavailability duration field 1820 (9 bits) that carries information regarding the unavailability duration (how long the candidate shared AP is unavailable for).

[0169] In an embodiment, the Reservedl field 1380 may be used to carry information (e.g., the information mentioned above for solutions #1-3) in addition to the Reserved2 field 1385 and the Reserved3 field 1390 carrying DUO information.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0170] Figure 19 is a diagram showing a block ACK bitmap filed format for providing information regarding the estimated processing time and DUO information, according to some embodiments.

[0171] The diagram shows another example of solution #4 mentioned above. In this example, when the Reserved2 field 1385 and Reserved 3 are used for carrying DUO information for the IDC issue, the Reservedl field 1380 may be used for carrying information regarding the estimated processing time for traffic that the candidate shared AP wishes to process.

[0172] For example, the Reservedl field 1380 may include a processing time of data field 1910 (9 bits) that carries information regarding the estimated processing time, the Reserved2 field 1385 may include a start time of unavailable duration field 1920 (9 bit) that carries information regarding the start time of when the candidate shared AP is unavailable, and the Reserved3 field 1390 may include an unavailability duration field 1930 (9 bits) that carries information regarding the unavailability duration.

[0173] More generally, any combination of the information mentioned above for solutions #1-4 can be carried in the block ACK bitmap field. For example, the block ACK bitmap field may carry AC / TID / SCS information and DUO information. As another example, the block ACK bitmap field may carry AC / TID / SCS information, DUO information, and information regarding the estimated processing time. While certain frame / field formats are shown in the diagrams and described herein, it should be appreciated that other frame / field formats can be used to achieve the same / similar result. Thus, the frame / field formats disclosed herein should not be regarded as limiting embodiments to particular formats.

[0174] A case is now considered where the initial control response frame is an aggregation of a multi-STA BA frame and a QoS null frame. In this case, instead of including the AC / SCSID / TID information in the multi-STA BA frame (e.g., as described for solutions #2 and 3), the relevant information may be included in the QoS control field of the QoS null frame or the buffer status report (BSR) control field of the aggregated control (A-control) field.Information regarding the estimated processing time and / or information regarding the maximum allowable delay may be included in the multi-STA BA frame (as described for solution #4).

[0175] With the initial control response frame format described herein, the sharing AP may learn the AC / SCSID / TID information regarding queued traffic and / or periodic low latency traffic of candidate shared AP(s), as well as the estimated processing times and allowable maximum delays for traffic that the candidate shared AP(s) wish to process during c-TDMA. Also, through the DUO information, the sharing AP may identify the time periods during which candidate shared AP(s) cannot operate. This allows the sharing AP to more effectively decide Docket No. 1002P25009W01Client Matter No. P25-009W01which candidate shared AP(s) should be allocated the TXOP (which candidate shared APs should participate in c-TDMA) and when to allocate the TXOP to the candidate shared AP(s).

[0176] Turning now to Figure 20, a method 2000 will be described for providing feedback information, in accordance with an example embodiment. The method 2000 may be performed by a candidate shared AP during a polling phase of c-TDMA. The candidate shared AP may be implemented by a wireless device (e.g., wireless device 104).

[0177] Additionally, although shown in a particular order, in some embodiments the operations of the method 2000 (and the other methods shown in the other figures) may be performed in a different order. For example, although the operations of the method 2000 are shown in a sequential order, some of the operations may be performed in partially or entirely overlapping time periods.

[0178] At operation 2005, the candidate shared AP receives an initial control frame from the sharing AP that polls the candidate shared AP regarding participating in c-TDMA.

[0179] At operation 2010, responsive to receiving the initial control frame, the candidate shared AP transmits an initial control response frame to the sharing AP, wherein the initial control response frame comprises a multi-station block acknowledgement frame that includes a block acknowledgement bitmap field that is repurposed to carry information regarding a willingness of the candidate shared AP to participate in the c-TDMA.

[0180] In an embodiment, as shown by block 2015, the information carried in the block acknowledgement bitmap field includes an indication that the candidate shared AP wishes to participate in the c-TDMA (i.e., the candidate shared AP is interested in participating in the c-TDMA) and / or traffic characteristic information of traffic that the candidate shared AP wishes to process in a BSS operated by the candidate shared AP during the c-TDMA. In an embodiment, the traffic characteristic information includes one or more of: AC information, SCSID information, and TID information. In an embodiment, the presence of the traffic characteristic information (even without the indication that the candidate shared AP wishes to participate in the c-TDMA) implicitly indicates that the candidate shared AP wishes to participate in the c-TDMA.

[0181] In an embodiment, as shown by block, 2020, the information carried in the block acknowledgement bitmap field includes information regarding an estimated processing time for traffic that the candidate shared AP wishes to process in a BSS operated by the candidate shared AP during the c-TDMA and / or information regarding an allowable delay for the traffic that the candidate shared AP wishes to process in the BSS during the c-TDMA.Docket No. 1002P25009W01Client Matter No. P25-009W01

[0182] In an embodiment, as shown by block 2025, the information carried in the block acknowledgement bitmap field includes dynamic unavailability operation information regarding when the candidate shared AP is unavailable. In an embodiment, the dynamic unavailability operation information includes information regarding an unavailability start time and information regarding an unavailability duration.

[0183] More generally, the block acknowledgement bitmap field may carry any combination of the information mentioned in block 2015, block 2020, and block 2025. Also, such information can be carried in a single block acknowledgement bitmap field (of a single per AID TID information field) or across multiple block acknowledgement bitmap fields (across multiple per AID TID information fields).

[0184] In an embodiment, at operation 2030, the candidate shared AP receives a control frame indicating that the sharing AP is sharing a TXOP owned by the sharing AP with the candidate shared AP as part of the c-TDMA, wherein the sharing AP selected the candidate shared AP to participate in the c-TDMA based on the information carried in the block acknowledgement bitmap field. In an embodiment, the initial control frame is a BSRP frame.

[0185] In an embodiment, at operation 2035, responsive to receiving the control frame, the candidate shared AP processes traffic in a BSS operated by the candidate shared AP during a portion of the TXOP shared by the sharing AP with the candidate shared AP.

[0186] Turning now to Figure 21, a method 2100 will be described for polling candidate shared APs, in accordance with an example embodiment. The method 2100 may be performed by a sharing AP during a polling phase of c-TDMA. The sharing AP may be implemented by a wireless device (e.g., wireless device 104).

[0187] At operation 2105, the sharing AP transmits an initial control frame to poll candidate shared APs regarding participating in the c-TDMA. In an embodiment, the initial control frame is a BSRP frame. In an embodiment, the initial control frame includes information regarding which portion of the TXOP the sharing AP is willing to share.

[0188] At operation 2110, the sharing AP receives one or more multi-station block acknowledgement frames from one or more candidate shared APs as a response to the initial control frame.

[0189] At operation 2115, the sharing AP extracts, from each of the one or more multi-station block acknowledgement frames, information from a repurposed block acknowledgement bitmap field included in the multi-station block acknowledgement frame.

[0190] In an embodiment, as shown in block 2120, the extracted information includes information regarding whether a given candidate shared AP from the one or more candidate Docket No. 1002P25009W01Client Matter No. P25-009W01shared APs wishes to participate in the c-TDMA (i.e., whether the given candidate shared AP is interested in participating in the c-TDMA) and / or traffic characteristic information of traffic that the given candidate shared AP wishes to process in a BSS operated by the given candidate shared AP during the c-TDMA. In an embodiment, the traffic characteristic information includes one or more of: AC information, SCSID information, and TID information. In an embodiment, the presence of the traffic characteristic information (even without an indication that the given candidate shared AP wishes to participate in the c-TDMA) implicitly indicates that the given candidate shared AP wishes to participate in the c-TDMA.

[0191] In an embodiment, as shown in block 2125, the extracted information includes information regarding an estimated processing time for traffic that a given candidate shared AP from the one or more candidate shared APs wishes to process in a BSS operated by the given candidate shared AP during the c-TDMA and / or information regarding an allowable delay for the traffic that the given candidate shared AP wishes to process in the BSS during the c-TDMA.

[0192] In an embodiment, as shown in block 2130, the extracted information includes dynamic unavailability operation information regarding when a given candidate shared AP from the one or more candidate shared APs is unavailable. In an embodiment, the dynamic unavailability operation information includes information regarding an unavailability start time and information regarding an unavailability duration.

[0193] More generally, the extracted information may include any combination of the information mentioned in block 2120, block 2125, and block 2130. Also, such information can be extracted from a single block acknowledgement bitmap field (of a single per AID TID information field) from multiple block acknowledgement bitmap field (from multiple per AID TID information fields).

[0194] At operation 2135, the sharing AP selects one or more of the one or more candidate shared APs to participate in the c-TDMA based on the information extracted from the one or more multi-station block acknowledgement frames.

[0195] At operation 2140, the sharing AP shares a TXOP owned by the sharing AP with the selected one or more candidate shared APs. In an embodiment, the sharing AP determines an order in which to share the TXOP with the selected one or more candidate shared APs based on the information extracted from the one or more multi-station block acknowledgement frames and shares the TXOP with the selected one or more candidate shared APs in the determined order.

[0196] While embodiments have been primarily described in a c-TDMA context, embodiments are not so limited. Embodiments can be used in any context where a wireless Docket No. 1002P25009W01Client Matter No. P25-009W01device wishes to provide feedback information to another wireless device via an initial control frame and initial control response frame exchange. For example, a first wireless device may receive an initial control frame from a second wireless device and responsive to receiving the initial control frame, the first wireless device may transmit a multi-station block acknowledgement frame (functioning as an initial control response frame) that includes a block acknowledgement information field that includes a plurality of per AID TID information fields, with each of the per AID TID information fields carrying different types of feedback information unrelated to acknowledgements. The first wireless device may function as a non-AP STA in the wireless network and the second wireless device may function as an AP (or vice versa). In an embodiment, the plurality of per AID TID information fields includes a first per AID TID information field that carries dynamic unavailability operation information and / or a second per AID TID information field that carries a low latency traffic indication. In an embodiment, the first per AID TID information field includes an AID TID info field, a block acknowledgement starting sequence control field, and a block acknowledgement bitmap field, wherein the block acknowledgement bitmap field has a length of four octets and is repurposed to carry at least a portion of the dynamic unavailability operation information.

[0197] Although many of the solutions and techniques provided herein have been described with reference to a WLAN system, it should be understood that these solutions and techniques are also applicable to other network environments, such as cellular telecommunication networks, wired networks, etc. In some embodiments, the solutions and techniques provided herein may be or may be embodied in an article of manufacture in which a non-transitory machine-readable medium (such as microelectronic memory) has stored thereon instructions which program one or more data processing components (generically referred to here as a “processor” or “processing unit”) to perform the operations described herein. In other embodiments, some of these operations might be performed by specific hardware components that contain hardwired logic (e.g., dedicated digital filter blocks and state machines). Those operations might alternatively be performed by any combination of programmed data processing components and fixed hardwired circuit components.

[0198] In some cases, an embodiment may be an apparatus (e.g., an AP STA, a non-AP STA, or another network or computing device) that includes one or more hardware and software logic structures for performing one or more of the operations described herein. For example, as described herein, an apparatus may include a memory unit, which stores instructions that may be executed by a hardware processor installed in the apparatus. The apparatus may also includeDocket No. 1002P25009W01Client Matter No. P25-009W01one or more other hardware or software elements, including a network interface, a display device, etc.

[0199] Some portions of the preceding detailed descriptions have been presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the ways used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consi stent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

[0200] It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. The present disclosure can refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage systems.

[0201] The present disclosure also relates to an apparatus for performing the operations herein. This apparatus can be specially constructed for the intended purposes, or it can include a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. For example, a computer system or other data processing system may carry out the computer-implemented methods described herein in response to its processor executing a computer program (e.g., a sequence of instructions) contained in a memory or other non-transitory machine-readable storage medium. Such a computer program can be stored in a computer readable storage medium, such as, but not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions, each coupled to a computer system bus.

[0202] The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems can be used with programs in accordance with the teachings herein, or it can prove convenient to construct a more specialized apparatus to perform the method. The structure for a variety of these systems will Docket No. 1002P25009W01Client Matter No. P25-009W01appear as set forth in the description below. In addition, the present disclosure is not described with reference to any particular programming language. It will be appreciated that a variety of programming languages can be used to implement the teachings of the disclosure as described herein.

[0203] The present disclosure can be provided as a computer program product, or software, that can include a machine-readable medium having stored thereon instructions, which can be used to program a computer system (or other electronic devices) to perform a process according to the present disclosure. A machine-readable medium includes any mechanism for storing information in a form readable by a machine (e.g., a computer). In some embodiments, a machine-readable (e.g., computer-readable) medium includes a machine (e.g., a computer) readable storage medium such as a read only memory (“ROM”), random access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory components, etc.

[0204] In the foregoing specification, embodiments of the disclosure have been described with reference to specific example embodiments thereof. It will be evident that various modifications can be made thereto without departing from the broader spirit and scope of embodiments of the disclosure as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.Docket No. 1002P25009W01Client Matter No. P25-009W01

Claims

CLAIMSWhat is claimed is:

1. A method performed by a candidate shared access point (AP) during a coordinated time division multiple access (c-TDMA) polling phase, the method comprising:receiving an initial control frame from the sharing AP that polls the candidate shared AP regarding participating in c-TDMA; andresponsive to receiving the initial control frame, transmitting an initial control response frame to the sharing AP, wherein the initial control response frame comprises a multi-station block acknowledgement frame that includes a block acknowledgement bitmap field that is repurposed to carry information regarding a willingness of the candidate shared AP to participate in the c-TDMA.

2. The method of claim 1, wherein the information carried in the block acknowledgement bitmap field includes an indication that the candidate shared AP wishes to participate in the c-TDMA.

3. The method of claim 2, wherein the information carried in the block acknowledgement bitmap field further includes traffic characteristic information of traffic that the candidate shared AP wishes to process in a basic service set (BSS) operated by the candidate shared AP during the c-TDMA.

4. The method of claim 3, wherein the traffic characteristic information includes one or more of: access category (AC) information, stream classification service identifier (SCSID) information, and traffic identifier (TID) information.

5. The method of claim 1, wherein the information carried in the block acknowledgement bitmap field includes traffic characteristic information of traffic that the candidate shared AP wishes to process in a basic service set (BSS) operated by the candidate shared AP during the c-TDMA, wherein a presence of the traffic characteristic information implicitly indicates that the candidate shared AP wishes to participate in the c-TDMA.

6. The method of claim 1, wherein the information carried in the block acknowledgement bitmap field includes information regarding an estimated processing time or expiry time for traffic that the candidate shared AP wishes to process in a basic service set (BSS) operated by the candidate shared AP during the c-TDMA.Docket No. 1002P25009W01Client Matter No. P25-009W017. The method of claim 6, wherein the information carried in the block acknowledgement bitmap field further includes information regarding an allowable delay for the traffic that the candidate shared AP wishes to process in the BSS during the c-TDMA.

8. The method of claim 1, wherein the information carried in the block acknowledgement bitmap field includes dynamic unavailability operation information regarding when the candidate shared AP is unavailable.

9. The method of claim 8, wherein the dynamic unavailability operation information includes information regarding an unavailability start time and information regarding an unavailability duration.

10. The method of claim 8, wherein the information carried in the block acknowledgement bitmap field further includes one or both of: an explicit indication that the candidate shared AP wishes to participate in the c-TDMA and traffic characteristic information of traffic that the candidate shared AP wishes to process in a basic service set (BSS) operated by the candidate shared AP during the c-TDMA.

11. The method of claim 8, wherein the information carried in the block acknowledgement bitmap field further includes information regarding an estimated processing time or expiry time for traffic that the candidate shared AP wishes to process in a basic service set (BSS) operated by the candidate shared AP during the c-TDMA.

12. The method of claim 1, further comprising:receiving a control frame indicating that the sharing AP is sharing a transmission opportunity (TXOP) owned by the sharing AP with the candidate shared AP as part of the c-TDMA, wherein the sharing AP selected the candidate shared AP to participate in the c-TDMA based on the information carried in the block acknowledgement bitmap field; andresponsive to receiving the control frame, processing traffic in a basic service set (BSS) operated by the candidate shared AP during a portion of the TXOP shared by the sharing AP with the candidate shared AP.

13. The method of claim 1, wherein the initial control frame is a buffer status report poll (BSRP) frame.Docket No. 1002P25009W01Client Matter No. P25-009W0114. A method performed by a sharing access point (AP) during a coordinated time division multiple access (c-TDMA) polling phase, the method comprising:transmitting an initial control frame to poll candidate shared APs regarding participating in the c-TDMA;receiving one or more multi-station block acknowledgement frames from one or more candidate shared APs as a response to the initial control frame;extracting, from each of the one or more multi-station block acknowledgement frames, information from a repurposed block acknowledgement bitmap field included in the multi-station block acknowledgement frame;selecting one or more of the one or more candidate shared APs to participate in the c- TDMA based on the information extracted from the one or more multi-station block acknowledgement frames; andsharing a transmission opportunity (TXOP) owned by the sharing AP with the selected one or more candidate shared APs.

15. The method of claim 14, wherein the information extracted from the one or more multistation block acknowledgement frames includes information regarding whether a given candidate shared AP from the one or more candidate shared APs wishes to participate in the c-TDMA.

16. The method of claim 15, wherein the information extracted from the one or more multistation block acknowledgement frames further includes traffic characteristic information of traffic that the given candidate shared AP wishes to process in a basic service set (BSS) operated by the given candidate shared AP during the c-TDMA.

17. The method of claim 16, wherein the traffic characteristic information includes one or more of: access category (AC) information, stream classification service identifier (SCSID) information, and traffic identifier (TID) information.

18. The method of claim 14, wherein the information extracted from the one or more multistation block acknowledgement frames includes traffic characteristic information of traffic that a given candidate shared AP from the one or more candidate shared APs wishes to process in a basic service set (BSS) operated by the given candidate shared AP during the c-TDMA, wherein a presence of the traffic characteristic information implicitly indicates that the given candidate shared AP wishes to participate in the c-TDMA.Docket No. 1002P25009W01Client Matter No. P25-009W0119. The method of claim 14, wherein the information extracted from the one or more multistation block acknowledgement frames includes information regarding an estimated processing time or expiry time for traffic that a given candidate shared AP from the one or more candidate shared APs wishes to process in a basic service set (BSS) operated by the given candidate shared AP during the c-TDMA.

20. The method of claim 19, wherein the information extracted from the one or more multistation block acknowledgement frames further includes information regarding an allowable delay for the traffic that the given candidate shared AP wishes to process in the BSS during the c-TDMA.

21. The method of claim 14, wherein the information extracted from the one or more multistation block acknowledgement frames includes dynamic unavailability operation information regarding when a given candidate shared AP from the one or more candidate shared APs is unavailable.

22. The method of claim 21, wherein the dynamic unavailability operation information includes information regarding an unavailability start time and information regarding an unavailability duration.

23. The method of claim 21, wherein the information extracted from the one or more multistation block acknowledgement frames further includes one or both of: an explicit indication that the given candidate shared AP wishes to participate in the c-TDMA and traffic characteristic information of traffic that the given candidate shared AP wishes to process in a basic service set (BSS) operated by the given candidate shared AP during the c-TDMA.

24. The method of claim 21, wherein the information extracted from the one or more multistation block acknowledgement frames further includes information regarding an estimated processing time or expiry time for traffic that the given candidate shared AP wishes to process in a basic service set (BSS) operated by the given candidate shared AP during the c-TDMA.

25. The method of claim 14, wherein the initial control frame includes information regarding which portion of the TXOP the sharing AP is willing to share.Docket No. 1002P25009W01Client Matter No. P25-009W0126. The method of claim 14, further comprising:determining an order in which to share the TXOP with the selected one or more candidate shared APs based on the information extracted from the one or more multi-station block acknowledgement frames.

27. The method of claim 26, wherein the initial control frame is a buffer status report poll (BSRP) frame.

28. A method performed by a first wireless device in a wireless network, the method comprising:receiving an initial control frame from a second wireless device in the wireless network;andresponsive to receiving the initial control frame, transmitting a multi-station block acknowledgement frame that includes a block acknowledgement information field that includes a plurality of per association identifier (AID) traffic identifier (TID) information fields, with each of the per AID TID information fields carrying different types of feedback information unrelated to acknowledgements.

29. The method of claim 28, wherein the first wireless device functions as a non-access point station (non-AP STA) in the wireless network and the second wireless device functions as an access point (AP) in the wireless network.

30. The method of claim 29, wherein the plurality of per AID TID information fields includes a first per AID TID information field that carries dynamic unavailability operation information.

31. The method of claim 30, wherein the plurality of per AID TID information fields further includes a second per AID TID information field that carries a low latency traffic indication.

32. The method of claim 30, wherein the first per AID TID information field includes an AID TID info field, a block acknowledgement starting sequence control field, and a block acknowledgement bitmap field, wherein the block acknowledgement bitmap field has a length of four octets and is repurposed to carry at least a portion of the dynamic unavailability operation information.Docket No. 1002P25009W01Client Matter No. P25-009W0133. A wireless device configured to implement a candidate shared access point (AP), the wireless device comprising:a radio frequency transceiver;a memory device storing a set of instructions; anda processor coupled to the memory device, wherein the set of instructions, when executed by the processor, causes the candidate shared AP to perform the method of any one of claims 1-13.

34. A wireless device configured to implement a sharing access point (AP), the wireless device comprising:a radio frequency transceiver;a memory device storing a set of instructions; anda processor coupled to the memory device, wherein the set of instructions, when executed by the processor, causes the sharing AP to perform the method of any one of claims 14-27.

35. A wireless device comprising:a radio frequency transceiver;a memory device storing a set of instructions; anda processor coupled to the memory device, wherein the set of instructions, when executed by the processor, causes the wireless device to perform the method of any one of claims 28-32.Docket No. 1002P25009W01Client Matter No. P25-009W01

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