LINK ADAPTATION REPORTING

Methods, apparatuses, and computer readable media for providing link adaptation information, where a station (STA) comprises processing circuitry configured to: decode, from an access point (AP), a request to send (RTS) frame, determine link adaptation information, and encode, for transmission to the AP, a clear-to-send (CTS) frame, the CTS frame comprising an indication of the link adaptation information. And where an AP comprises processing circuitry configured to: encode, for transmission to a STA, a RTS frame, decode, from the STA, a CTS frame, the CTS frame comprising an indication of the link adaptation information, determining an encoding rate for a PPDU based on the link adaptation information, and encode, for transmission to the STA, the PPDU.

TECHNICAL FIELD

Embodiments relate to link adaptation reporting of a responder station (STA) to a initiator access point (AP), in accordance with wireless local area networks (WLANs) and Wi-Fi networks including networks operating in accordance with different versions or generations of the IEEE 802.11 family of standards.

BACKGROUND

Efficient use of the resources of a wireless local-area network (WLAN) is important to provide bandwidth and acceptable response times to the users of the WLAN. However, often there are many devices trying to share the same resources and some devices may be limited by the communication protocol they use or by their hardware bandwidth. Moreover, wireless devices may need to operate with both newer protocols and with legacy device protocols on different bands and on different channels.

DESCRIPTION

FIG.1is a block diagram of a radio architecture100in accordance with some embodiments. Radio architecture100may include radio front-end module (FEM) circuitry104, radio IC circuitry106and baseband processing circuitry108. Radio architecture100as shown includes both Wireless Local Area Network (WLAN) functionality and Bluetooth® (BT) functionality although embodiments are not so limited. In this disclosure, “WLAN” and “Wi-Fi” are used interchangeably.

FEM circuitry104may include a WLAN or Wi-Fi FEM circuitry104A and a Bluetooth® (BT) FEM circuitry104B. The WLAN FEM circuitry104A may include a receive signal path comprising circuitry configured to operate on WLAN RF signals received from one or more antennas101, to amplify the received signals and to provide the amplified versions of the received signals to the WLAN radio IC circuitry106A for further processing. The BT FEM circuitry104B may include a receive signal path which may include circuitry configured to operate on BT RF signals received from one or more antennas101, to amplify the received signals and to provide the amplified versions of the received signals to the BT radio IC circuitry106B for further processing. FEM circuitry104A may also include a transmit signal path which may include circuitry configured to amplify WLAN signals provided by the radio IC circuitry106A for wireless transmission by one or more of the antennas101. In addition, FEM circuitry104B may also include a transmit signal path which may include circuitry configured to amplify BT signals provided by the radio IC circuitry106B for wireless transmission by the one or more antennas. In the embodiment ofFIG.1, although FEM circuitry104A and FEM circuitry104B are shown as being distinct from one another, embodiments are not so limited, and include within their scope the use of an FEM (not shown) that includes a transmit path and/or a receive path for both WLAN and BT signals, or the use of one or more FEM circuitries where at least some of the FEM circuitries share transmit and/or receive signal paths for both WLAN and BT signals.

Radio IC circuitry106as shown may include WLAN radio IC circuitry106A and BT radio IC circuitry106B. The WLAN radio IC circuitry106A may include a receive signal path which may include circuitry to down-convert WLAN RF signals received from the FEM circuitry104A and provide baseband signals to WLAN baseband processing circuitry108A. BT radio IC circuitry106B may in turn include a receive signal path which may include circuitry to down-convert BT RF signals received from the FEM circuitry104B and provide baseband signals to BT baseband processing circuitry108B. WLAN radio IC circuitry106A may also include a transmit signal path which may include circuitry to up-convert WLAN baseband signals provided by the WLAN baseband processing circuitry108A and provide WLAN RF output signals to the FEM circuitry104A for subsequent wireless transmission by the one or more antennas101. BT radio IC circuitry106B may also include a transmit signal path which may include circuitry to up-convert BT baseband signals provided by the BT baseband processing circuitry108B and provide BT RF output signals to the FEM circuitry104B for subsequent wireless transmission by the one or more antennas101. In the embodiment ofFIG.1, although radio IC circuitries106A and106B are shown as being distinct from one another, embodiments are not so limited, and include within their scope the use of a radio IC circuitry (not shown) that includes a transmit signal path and/or a receive signal path for both WLAN and BT signals, or the use of one or more radio IC circuitries where at least some of the radio IC circuitries share transmit and/or receive signal paths for both WLAN and BT signals.

Baseband processing circuitry108may include a WLAN baseband processing circuitry108A and a BT baseband processing circuitry108B. The WLAN baseband processing circuitry108A may include a memory, such as, for example, a set of RAM arrays in a Fast Fourier Transform or Inverse Fast Fourier Transform block (not shown) of the WLAN baseband processing circuitry108A. Each of the WLAN baseband processing circuitry108A and the BT baseband circuitry108B may further include one or more processors and control logic to process the signals received from the corresponding WLAN or BT receive signal path of the radio IC circuitry106, and to also generate corresponding WLAN or BT baseband signals for the transmit signal path of the radio IC circuitry106. Each of the baseband processing circuitries108A and108B may further include physical layer (PHY) and medium access control layer (MAC) circuitry, and may further interface with application processor111for generation and processing of the baseband signals and for controlling operations of the radio IC circuitry106.

Referring still toFIG.1, according to the shown embodiment, WLAN-BT coexistence circuitry113may include logic providing an interface between the WLAN baseband processing circuitry108A and the BT baseband circuitry108B to enable use cases requiring WLAN and BT coexistence. In addition, a switch103may be provided between the WLAN FEM circuitry104A and the BT FEM circuitry104B to allow switching between the WLAN and BT radios according to application needs. In addition, although the antennas101are depicted as being respectively connected to the WLAN FEM circuitry104A and the BT FEM circuitry104B, embodiments include within their scope the sharing of one or more antennas as between the WLAN and BT FEMs, or the provision of more than one antenna connected to each of FEM circuitry104A or FEM circuitry104B.

In some embodiments, the front-end module circuitry104, the radio IC circuitry106, and baseband processing circuitry108may be provided on a single radio card, such as wireless radio card102. In some other embodiments, the one or more antennas101, the FEM circuitry104and the radio IC circuitry106may be provided on a single radio card. In some other embodiments, the radio IC circuitry106and the baseband processing circuitry108may be provided on a single chip or IC, such as IC112.

In some embodiments, the radio architecture100may be configured for high-efficiency (HE) Wi-Fi (HEW) communications in accordance with the IEEE 802.11ax standard. In these embodiments, the radio architecture100may be configured to communicate in accordance with an OFDMA technique, although the scope of the embodiments is not limited in this respect.

In some embodiments, as further shown inFIG.1, the BT baseband circuitry108B may be compliant with a Bluetooth® (BT) connectivity standard such as Bluetooth®, Bluetooth® 4.0 or Bluetooth® 5.0, or any other iteration of the Bluetooth® Standard. In embodiments that include BT functionality as shown for example inFIG.1, the radio architecture100may be configured to establish a BT synchronous connection oriented (SCO) link and/or a BT low energy (BT LE) link. In some of the embodiments that include functionality, the radio architecture100may be configured to establish an extended SCO (eSCO) link for BT communications, although the scope of the embodiments is not limited in this respect. In some of these embodiments that include a BT functionality, the radio architecture may be configured to engage in a BT Asynchronous Connection-Less (ACL) communications, although the scope of the embodiments is not limited in this respect. In some embodiments, as shown inFIG.1, the functions of a BT radio card and WLAN radio card may be combined on a single wireless radio card, such as single wireless radio card102, although embodiments are not so limited, and include within their scope discrete WLAN and BT radio cards

In some embodiments, the radio architecture100may include other radio cards, such as a cellular radio card configured for cellular (e.g., 3GPP such as LTE, LTE-Advanced or 5G communications).

In some IEEE 802.11 embodiments, the radio architecture100may be configured for communication over various channel bandwidths including bandwidths having center frequencies of about nine hundred MHz, 2.4 GHz, 5 GHZ, and bandwidths of about 1 MHz, 2 MHz, 2.5 MHz, 4 MHZ, 5 MHz, 8 MHz, 10 MHz, 16 MHz, 20 MHz, 40 MHz, 80 MHz (with contiguous bandwidths) or 80+80 MHz (160 MHz) (with non-contiguous bandwidths). In some embodiments, a 320 MHz channel bandwidth may be used. The scope of the embodiments is not limited with respect to the above center frequencies however.

FIG.2illustrates FEM circuitry200in accordance with some embodiments. The FEM circuitry200is one example of circuitry that may be suitable for use as the WLAN and/or BT FEM circuitry104A/104B (FIG.1), although other circuitry configurations may also be suitable.

In some embodiments, the FEM circuitry200may include a TX/RX switch202to switch between transmit mode and receive mode operation. The FEM circuitry200may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry200may include a low-noise amplifier (LNA)206to amplify received RF signals203and provide the amplified received RF signals207as an output (e.g., to the radio IC circuitry106(FIG.1)). The transmit signal path of the circuitry200may include a power amplifier (PA) to amplify input RF signals209(e.g., provided by the radio IC circuitry106), and one or more filters212, such as band-pass filters (BPFs), low-pass filters (LPFs) or other types of filters, to generate RF signals215for subsequent transmission (e.g., by one or more of the antennas101(FIG.1)).

In some dual-mode embodiments for Wi-Fi communication, the FEM circuitry200may be configured to operate in either the 2.4 GHz frequency spectrum or the 5 GHz frequency spectrum. In these embodiments, the receive signal path of the FEM circuitry200may include a receive signal path duplexer204to separate the signals from each spectrum as well as provide a separate LNA206for each spectrum as shown. In these embodiments, the transmit signal path of the FEM circuitry200may also include a power amplifier210and a filter212, such as a BPF, a LPF or another type of filter for each frequency spectrum and a transmit signal path duplexer214to provide the signals of one of the different spectrums onto a single transmit path for subsequent transmission by the one or more of the antennas101(FIG.1). In some embodiments, BT communications may utilize the 2.4 GHZ signal paths and may utilize the same FEM circuitry200as the one used for WLAN communications.

FIG.3illustrates radio integrated circuit (IC) circuitry300in accordance with some embodiments. The radio IC circuitry300is one example of circuitry that may be suitable for use as the WLAN or BT radio IC circuitry106A/106B (FIG.1), although other circuitry configurations may also be suitable.

In some embodiments, the radio IC circuitry300may include a receive signal path and a transmit signal path. The receive signal path of the radio IC circuitry300may include at least mixer circuitry302, such as, for example, down-conversion mixer circuitry, amplifier circuitry306and filter circuitry308. The transmit signal path of the radio IC circuitry300may include at least filter circuitry312and mixer circuitry314, such as, for example, up-conversion mixer circuitry. Radio IC circuitry300may also include synthesizer circuitry304for synthesizing a frequency305for use by the mixer circuitry302and the mixer circuitry314. The mixer circuitry302and/or314may each, according to some embodiments, be configured to provide direct conversion functionality. The latter type of circuitry presents a much simpler architecture as compared with standard super-heterodyne mixer circuitries, and any flicker noise brought about by the same may be alleviated for example through the use of OFDM modulation.FIG.3illustrates only a simplified version of a radio IC circuitry, and may include, although not shown, embodiments where each of the depicted circuitries may include more than one component. For instance, mixer circuitry302and/or314may each include one or more mixers, and filter circuitries308and/or312may each include one or more filters, such as one or more BPFs and/or LPFs according to application needs. For example, when mixer circuitries are of the direct-conversion type, they may each include two or more mixers.

In some embodiments, mixer circuitry302may be configured to down-convert RF signals207received from the FEM circuitry104(FIG.1) based on the synthesized frequency305provided by synthesizer circuitry304. The amplifier circuitry306may be configured to amplify the down-converted signals and the filter circuitry308may include a LPF configured to remove unwanted signals from the down-converted signals to generate output baseband signals307. Output baseband signals307may be provided to the baseband processing circuitry108(FIG.1) for further processing. In some embodiments, the output baseband signals307may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry302may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry314may be configured to up-convert input baseband signals311based on the synthesized frequency305provided by the synthesizer circuitry304to generate RF output signals209for the FEM circuitry104. The baseband signals311may be provided by the baseband processing circuitry108and may be filtered by filter circuitry312. The filter circuitry312may include a LPF or a BPF, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry302and the mixer circuitry314may each include two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion respectively with the help of synthesizer circuitry304. In some embodiments, the mixer circuitry302and the mixer circuitry314may each include two or more mixers each configured for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry302and the mixer circuitry314may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, the mixer circuitry302and the mixer circuitry314may be configured for super-heterodyne operation, although this is not a requirement.

Mixer circuitry302may comprise, according to one embodiment:

quadrature passive mixers (e.g., for the in-phase (I) and quadrature phase (Q) paths). In such an embodiment, RF input signal207fromFIG.3may be down-converted to provide I and Q baseband output signals to be sent to the baseband processor

In some embodiments, the LO signals may differ in duty cycle (the percentage of one period in which the LO signal is high) and/or offset (the difference between start points of the period). In some embodiments, the LO signals may have a 25% duty cycle and a 50% offset. In some embodiments, each branch of the mixer circuitry (e.g., the in-phase (I) and quadrature phase (Q) path) may operate at a 25% duty cycle, which may result in a significant reduction is power consumption.

The RF input signal207(FIG.2) may comprise a balanced signal, although the scope of the embodiments is not limited in this respect. The I and Q baseband output signals may be provided to low-nose amplifier, such as amplifier circuitry306(FIG.3) or to filter circuitry308(FIG.3).

In some embodiments, the output baseband signals307and the input baseband signals311may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals307and the input baseband signals311may be digital baseband signals. In these alternate embodiments, the radio IC circuitry may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry.

In some embodiments, the synthesizer circuitry304may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry304may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. According to some embodiments, the synthesizer circuitry304may include digital synthesizer circuitry. An advantage of using a digital synthesizer circuitry is that, although it may still include some analog components, its footprint may be scaled down much more than the footprint of an analog synthesizer circuitry. In some embodiments, frequency input into synthesizer circuitry304may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. A divider control input may further be provided by either the baseband processing circuitry108(FIG.1) or the application processor111(FIG.1) depending on the desired output frequency305. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table (e.g., within a Wi-Fi card) based on a channel number and a channel center frequency as determined or indicated by the application processor111.

In some embodiments, synthesizer circuitry304may be configured to generate a carrier frequency as the output frequency305, while in other embodiments, the output frequency305may be a fraction of the carrier frequency (e.g., one-half the carrier frequency, one-third the carrier frequency). In some embodiments, the output frequency305may be a LO frequency (fLo).

FIG.4illustrates a functional block diagram of baseband processing circuitry400in accordance with some embodiments. The baseband processing circuitry400is one example of circuitry that may be suitable for use as the baseband processing circuitry108(FIG.1), although other circuitry configurations may also be suitable. The baseband processing circuitry400may include a receive baseband processor (RX BBP)402for processing receive baseband signals309provided by the radio IC circuitry106(FIG.1) and a transmit baseband processor (TX BBP)404for generating transmit baseband signals311for the radio IC circuitry106. The baseband processing circuitry400may also include control logic406for coordinating the operations of the baseband processing circuitry400.

In some embodiments (e.g., when analog baseband signals are exchanged between the baseband processing circuitry400and the radio IC circuitry106), the baseband processing circuitry400may include ADC410to convert analog baseband signals received from the radio IC circuitry106to digital baseband signals for processing by the RX BBP402. In these embodiments, the baseband processing circuitry400may also include DAC412to convert digital baseband signals from the TX BBP404to analog baseband signals.

In some embodiments that communicate OFDM signals or OFDMA signals, such as through baseband processing circuitry108A, the TX BBP404may be configured to generate OFDM or OFDMA signals as appropriate for transmission by performing an inverse fast Fourier transform (IFFT). The RX BBP402may be configured to process received OFDM signals or OFDMA signals by performing an FFT. In some embodiments, the RX BBP402may be configured to detect the presence of an OFDM signal or OFDMA signal by performing an autocorrelation, to detect a preamble, such as a short preamble, and by performing a cross-correlation, to detect a long preamble. The preambles may be part of a predetermined frame structure for Wi-Fi communication.

FIG.5illustrates a WLAN 500 in accordance with some embodiments. The WLAN 500 may comprise a basis service set (BSS) that may include an access point (AP) AP502, a plurality of stations (STAs) STAs504, and a plurality of legacy devices506. In some embodiments, the STAs504and/or AP502are configured to operate in accordance with IEEE 802.11be extremely high throughput (EHT), WiFi8IEEE 802.11 ultra-high throughput (UHT), high efficiency (HE) IEEE 802.11ax, IEEE 802.11bn next generation or ultra-high reliability (UHR), and/or another IEEE 802.11 wireless communication standard. In some embodiments, the STAs504and/or AP502are configured to operate in accordance with IEEE P802.11be, and/or IEEE P802.11-REVme™, both of which are hereby included by reference in their entirety.

The AP502may use other communications protocols as well as the IEEE 802.11 protocol. The terms here may be termed differently in accordance with some embodiments. The IEEE 802.11 protocol may include using orthogonal frequency division multiple-access (OFDMA), time division multiple access (TDMA), and/or code division multiple access (CDMA). The IEEE 802.11 protocol may include a multiple access technique. For example, the IEEE 802.11 protocol may include space-division multiple access (SDMA) and/or multiple-user multiple-input multiple-output (MU-MIMO). There may be more than one AP502that is part of an extended service set (ESS). A controller (not illustrated) may store information that is common to the more than one APs502and may control more than one BSS, e.g., assign primary channels, colors, etc. AP502may be connected to the internet.

The legacy devices506may operate in accordance with one or more of IEEE 802.11 a/b/g/n/ac/ad/af/ah/aj/ay/ax/uht, or another legacy wireless communication standard. The legacy devices506may be STAs or IEEE STAs. The STAs504may be wireless transmit and receive devices such as cellular telephone, portable electronic wireless communication devices, smart telephone, handheld wireless device, wireless glasses, wireless watch, wireless personal device, tablet, or another device that may be transmitting and receiving using the IEEE 802.11 protocol such as IEEE 802.11be or another wireless protocol.

The AP502may communicate with legacy devices506in accordance with legacy IEEE 802.11 communication techniques. In example embodiments, the AP502may also be configured to communicate with STAs504in accordance with legacy IEEE 802.11 communication techniques.

In some embodiments, a HE, EHT, UHT frames may be configurable to have the same bandwidth as a channel. The HE, EHT, UHT frame may be a physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU). In some embodiments, PPDU may be an abbreviation for physical layer protocol data unit (PPDU). In some embodiments, there may be different types of PPDUs that may have different fields and different physical layers and/or different media access control (MAC) layers. For example, a single user (SU) PPDU, downlink (DL) PPDU, multiple-user (MU) PPDU, extended-range (ER) SU PPDU, and/or trigger-based (TB) PPDU. In some embodiments EHT may be the same or similar as HE PPDUs.

The bandwidth of a channel may be 20 MHz, 40 MHz, or 80 MHZ, 80+80 MHz, 160 MHz, 160+160 MHz, 320 MHz, 320+320 MHz, 640 MHz bandwidths. In some embodiments, the bandwidth of a channel less than 20 MHz may be 1 MHz, 1.25 MHz, 2.03 MHz, 2.5 MHz, 4.06 MHz, 5 MHz and 10 MHz, or a combination thereof or another bandwidth that is less or equal to the available bandwidth may also be used. In some embodiments the bandwidth of the channels may be based on a number of active data subcarriers. In some embodiments the bandwidth of the channels is based on 26, 52, 106, 242, 484, 996, or 2x996 active data subcarriers or tones that are spaced by 20 MHz. In some embodiments the bandwidth of the channels is 256 tones spaced by 20 MHz. In some embodiments the channels are multiple of 26 tones or a multiple of 20 MHz. In some embodiments a 20 MHz channel may comprise 242 active data subcarriers or tones, which may determine the size of a Fast Fourier Transform (FFT). An allocation of a bandwidth or a number of tones or sub-carriers may be termed a resource unit (RU) allocation in accordance with some embodiments.

In some embodiments, the 26-subcarrier RU and 52-subcarrier RU are used in the 20 MHz, 40 MHZ, 80 MHz, 160 MHz and 80+80 MHz OFDMA HE PPDU formats. In some embodiments, the 106-subcarrier RU is used in the 20 MHz, 40 MHz, 80 MHz, 160 MHz and 80+80 MHz OFDMA and MU-MIMO HE PPDU formats. In some embodiments, the 242-subcarrier RU is used in the 40 MHz, 80 MHz, 160 MHz and 80+80 MHz OFDMA and MU-MIMO HE PPDU formats. In some embodiments, the 484-subcarrier RU is used in the 80 MHz, 160 MHz and 80+80 MHz OFDMA and MU-MIMO HE PPDU formats. In some embodiments, the 996-subcarrier RU is used in the 160 MHz and 80+80 MHz OFDMA and MU-MIMO HE PPDU formats.

A HE, EHT, UHT, UHT, or UHR frame may be configured for transmitting a number of spatial streams, which may be in accordance with MU-MIMO and may be in accordance with OFDMA. In other embodiments, the AP502, STA504, and/or legacy device506may also implement different technologies such as code division multiple access (CDMA) 2000, CDMA 2000 1×, CDMA 2000 Evolution-Data Optimized (EV-DO), Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Long Term Evolution (LTE), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), Bluetooth®, low-power Bluetooth®, or other technologies.

In accordance with some IEEE 802.11 embodiments, e.g., IEEE 802.11EHT/ax/be embodiments, a HE AP502may operate as a master station which may be arranged to contend for a wireless medium (e.g., during a contention period) to receive exclusive control of the medium for a transmission opportunity (TXOP). The AP502may transmit an EHT/HE trigger frame transmission, which may include a schedule for simultaneous UL/DL transmissions from STAs504. The AP502may transmit a time duration of the TXOP and sub-channel information. During the TXOP, STAs504may communicate with the AP502in accordance with a non-contention based multiple access technique such as OFDMA or MU-MIMO. This is unlike conventional WLAN communications in which devices communicate in accordance with a contention-based communication technique, rather than a multiple access technique. During the HE, EHT, UHR control period, the AP502may communicate with STAs504using one or more HE or EHT frames. During the TXOP, the HE STAs504may operate on a sub-channel smaller than the operating range of the AP502. During the TXOP, legacy stations refrain from communicating. The legacy stations may need to receive the communication from the HE AP502to defer from communicating.

In accordance with some embodiments, during the TXOP the STAs504may contend for the wireless medium with the legacy devices506being excluded from contending for the wireless medium during the master-sync transmission. In some embodiments the trigger frame may indicate an UL-MU-MIMO and/or UL OFDMA TXOP. In some embodiments, the trigger frame may include a DL UL-MU-MIMO and/or DL OFDMA with a schedule indicated in a preamble portion of trigger frame.

In some embodiments, the multiple-access technique used during the HE or EHT TXOP may be a scheduled OFDMA technique, although this is not a requirement. In some embodiments, the multiple access technique may be a time-division multiple access (TDMA) technique or a frequency division multiple access (FDMA) technique. In some embodiments, the multiple access technique may be a space-division multiple access (SDMA) technique. In some embodiments, the multiple access technique may be a Code division multiple access (CDMA).

The AP502may also communicate with legacy devices506and/or STAs504in accordance with legacy IEEE 802.11 communication techniques. In some embodiments, the AP502may also be configurable to communicate with STAs504outside the TXOP in accordance with legacy IEEE 802.11 or IEEE 802.11EHT/UHR communication techniques, although this is not a requirement.

In some embodiments the STA504may be a “group owner” (GO) for peer-to-peer modes of operation. A wireless device may be a STA504or a HE AP502. The STA504may be termed a non-access point (AP) (non-AP) STA504, in accordance with some embodiments.

In some embodiments, the STA504and/or AP502may be configured to operate in accordance with IEEE 802.11mc. In example embodiments, the radio architecture ofFIG.1is configured to implement the STA504and/or the AP502. In example embodiments, the front-end module circuitry ofFIG.2is configured to implement the STA504and/or the AP502. In example embodiments, the radio IC circuitry ofFIG.3is configured to implement the HE STA504and/or the AP502. In example embodiments, the base-band processing circuitry ofFIG.4is configured to implement the STA504and/or the AP502.

In example embodiments, the STAs504, AP502, an apparatus of the STA504, and/or an apparatus of the AP502may include one or more of the following: the radio architecture ofFIG.1, the front-end module circuitry ofFIG.2, the radio IC circuitry ofFIG.3, and/or the base-band processing circuitry ofFIG.4.

In example embodiments, the radio architecture ofFIG.1, the front-end module circuitry ofFIG.2, the radio IC circuitry ofFIG.3, and/or the base-band processing circuitry ofFIG.4may be configured to perform the methods and operations/functions herein described in conjunction withFIGS.1-14.

In example embodiments, the STAs504and/or the AP502are configured to perform the methods and operations/functions described herein in conjunction withFIGS.1-14. In example embodiments, an apparatus of the STA504and/or an apparatus of the AP502are configured to perform the methods and functions described herein in conjunction withFIGS.1-14. The term Wi-Fi may refer to one or more of the IEEE 802.11 communication standards. AP and STA may refer to EHT/HE access point and/or EHT/HE station as well as legacy devices506.

In some embodiments, a HE AP STA may refer to an AP502and/or STAs504that are operating as EHT APs502. In some embodiments, when a STA504is not operating as an AP, it may be referred to as a non-AP STA or non-AP. In some embodiments, STA504may be referred to as either an AP STA or a non-AP. The AP502may be part of, or affiliated with, an AP MLD808, e.g., AP1830, AP2832, or AP3834. The STAs504may be part of, or affiliated with, a non-AP MLD809, which may be termed a ML non-AP logical entity. The BSS may be part of an extended service set (ESS), which may include multiple APs, access to the internet, and may include one or more management devices.

Machine (e.g., computer system)600may include a hardware processor602(e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory604and a static memory606, some or all of which may communicate with each other via an interlink (e.g., bus)608.

Specific examples of main memory604include Random Access Memory (RAM), and semiconductor memory devices, which may include, in some embodiments, storage locations in semiconductors such as registers. Specific examples of static memory606include non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; RAM; and CD-ROM and DVD-ROM disks.

The machine600may further include a display device610, an input device612(e.g., a keyboard), and a user interface (UI) navigation device614(e.g., a mouse). In an example, the display device610, input device612and UI navigation device614may be a touch screen display. The machine600may additionally include a mass storage (e.g., drive unit)616, a signal generation device618(e.g., a speaker), a network interface device620, and one or more sensors621, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The machine600may include an output controller628, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.). In some embodiments the processor602and/or instructions624may comprise processing circuitry and/or transceiver circuitry.

The mass storage616device may include a machine readable medium622on which is stored one or more sets of data structures or instructions624(e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions624may also reside, completely or at least partially, within the main memory604, within static memory606, or within the hardware processor602during execution thereof by the machine600. In an example, one or any combination of the hardware processor602, the main memory604, the static memory606, or the mass storage616device may constitute machine readable media.

Specific examples of machine-readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., EPROM or EEPROM) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; RAM; and CD-ROM and DVD-ROM disks.

An apparatus of the machine600may be one or more of a hardware processor602(e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory604and a static memory606, sensors621, network interface device620, antennas660, a display device610, an input device612, a UI navigation device614, a mass storage616, instructions624, a signal generation device618, and an output controller628. The apparatus may be configured to perform one or more of the methods and/or operations disclosed herein. The apparatus may be intended as a component of the machine600to perform one or more of the methods and/or operations disclosed herein, and/or to perform a portion of one or more of the methods and/or operations disclosed herein. In some embodiments, the apparatus may include a pin or other means to receive power. In some embodiments, the apparatus may include power conditioning hardware.

In an example, the network interface device620may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network626. In an example, the network interface device620may include one or more antennas660to wirelessly communicate using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. In some examples, the network interface device620may wirelessly communicate using Multiple User MIMO techniques. The term “transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the machine600, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

FIG.7illustrates a block diagram of an example wireless device700upon which any one or more of the techniques (e.g., methodologies or operations) discussed herein may perform. The wireless device700may be a HE device or HE wireless device. The wireless device700may be a HE STA504, HE AP502, and/or a HE STA or HE AP. A HE STA504, HE AP502, and/or a HE AP or HE STA may include some or all of the components shown inFIGS.1-7. The wireless device700may be an example machine600as disclosed in conjunction withFIG.6.

The wireless device700may include processing circuitry708. The processing circuitry708may include a transceiver702, physical layer circuitry (PHY circuitry)704, and MAC layer circuitry (MAC circuitry)706, one or more of which may enable transmission and reception of signals to and from other wireless devices700(e.g., HE AP502, HE STA504, and/or legacy devices506) using one or more antennas712. As an example, the PHY circuitry704may perform various encoding and decoding functions that may include formation of baseband signals for transmission and decoding of received signals. As another example, the transceiver702may perform various transmission and reception functions such as conversion of signals between a baseband range and a Radio Frequency (RF) range.

Accordingly, the PHY circuitry704and the transceiver702may be separate components or may be part of a combined component, e.g., processing circuitry708. In addition, some of the described functionality related to transmission and reception of signals may be performed by a combination that may include one, any or all of the PHY circuitry704the transceiver702, MAC circuitry706, memory710, and other components or layers. The MAC circuitry706may control access to the wireless medium. The wireless device700may also include memory710arranged to perform the operations described herein, e.g., some of the operations described herein may be performed by instructions stored in the memory710.

One or more of the memory710, the transceiver702, the PHY circuitry704, the MAC circuitry706, the antennas712, and/or the processing circuitry708may be coupled with one another. Moreover, although memory710, the transceiver702, the PHY circuitry704, the MAC circuitry706, the antennas712are illustrated as separate components, one or more of memory710, the transceiver702, the PHY circuitry704, the MAC circuitry706, the antennas712may be integrated in an electronic package or chip.

In some embodiments, the wireless device700may be a mobile device as described in conjunction withFIG.6. In some embodiments the wireless device700may be configured to operate in accordance with one or more wireless communication standards as described herein (e.g., as described in conjunction withFIGS.1-6, IEEE 802.11). In some embodiments, the wireless device700may include one or more of the components as described in conjunction withFIG.6(e.g., display device610, input device612, etc.) Although the wireless device700is illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processes operating on one or more processing elements.

In some embodiments, an apparatus of or used by the wireless device700may include various components of the wireless device700as shown inFIG.7and/or components fromFIGS.1-6. Accordingly, techniques and operations described herein that refer to the wireless device700may be applicable to an apparatus for a wireless device700(e.g., HE AP502and/or HE STA504), in some embodiments. In some embodiments, the wireless device700is configured to decode and/or encode signals, packets, and/or frames as described herein, e.g., PPDUs.

In some embodiments, the MAC circuitry706may be arranged to contend for a wireless medium during a contention period to receive control of the medium for a HE TXOP and encode or decode an HE PPDU. In some embodiments, the MAC circuitry706may be arranged to contend for the wireless medium based on channel contention settings, a transmitting power level, and a clear channel assessment level (e.g., an energy detect level).

The PHY circuitry704may be arranged to transmit signals in accordance with one or more communication standards described herein. For example, the PHY circuitry704may be configured to transmit a HE PPDU. The PHY circuitry704may include circuitry for modulation/demodulation, upconversion/downconversion, filtering, amplification, etc. In some embodiments, the processing circuitry708may include one or more processors. The processing circuitry708may be configured to perform functions based on instructions being stored in a RAM or ROM, or based on special purpose circuitry. The processing circuitry708may include a processor such as a general purpose processor or special purpose processor. The processing circuitry708may implement one or more functions associated with antennas712, the transceiver702, the PHY circuitry704, the MAC circuitry706, and/or the memory710. In some embodiments, the processing circuitry708may be configured to perform one or more of the functions/operations and/or methods described herein.

In mm Wave technology, communication between a station (e.g., the HE STAs504ofFIG.5or wireless device700) and an access point (e.g., the HE AP502ofFIG.5or wireless device700) may use associated effective wireless channels that are highly directionally dependent. To accommodate the directionality, beamforming techniques may be utilized to radiate energy in a certain direction with certain beamwidth to communicate between two devices. The directed propagation concentrates transmitted energy toward a target device in order to compensate for significant energy loss in the channel between the two communicating devices. Using directed transmission may extend the range of the millimeter-wave communication versus utilizing the same transmitted energy in omni-directional propagation.

FIG.8illustrates multi-link devices (MLD) s800, in accordance with some embodiments. Illustrated inFIG.8is ML logical entity 1806, ML logical entity 2807, AP MLD808, and non-AP MLD809. The ML logical entity 1806includes three STAs, STA1.1814.1, STA1.2814.2, and STA1.3814.3that operate in accordance with link 1802.1, link 2802.2, and link 3802.3, respectively.

The Links are different frequency bands such as 2.4 GHz band, 5 GHZ band, 6 GHz band, and so forth. ML logical entity 2807includes STA2.1816.1, STA2.2816.2, and STA2.3816.3that operate in accordance with link 1802.1, link 2802.2, and link 3802.3, respectively. In some embodiments ML logical entity 1806and ML logical entity 2807operate in accordance with a mesh network. Using three links enables the ML logical entity 1806and ML logical entity 2807to operate using a greater bandwidth and more reliably as they can switch to using a different link if there is interference or if one link is superior due to operating conditions.

The distribution system (DS)810indicates how communications are distributed and the DS medium (DSM)812indicates the medium that is used for the DS810, which in this case is the wireless spectrum.

AP MLD808includes AP1830, AP2832, and AP3834operating on link 1804.1, link 2804.2, and link 3804.3, respectively. AP MLD808includes a MAC ADDR854that may be used by applications to transmit and receive data across one or more of AP1830, AP2832, and AP3834. Each link may have an associated link ID. For example, as illustrated, link 3804.3has a link ID870.

AP1830, AP2832, and AP3834includes a frequency band, which are 2.4 GHz band 836, 5 GHz band 838, and 6 GHz band840, respectively. AP1830, AP2832, and AP3834includes different BSSIDs, which are BSSID842, BSSID844, and BSSID846, respectively. AP1830, AP2832, and AP3834includes different media access control (MAC) address (addr), which are MAC adder848, MAC addr850, and MAC addr852, respectively. The AP502is a AP MLD808, in accordance with some embodiments. The STA504is a non-AP MLD809, in accordance with some embodiments.

The non-AP MLD809includes non-AP STA1818, non-AP STA2820, and non-AP STA3822. Each of the non-AP STAs may have MAC addresses and the non-AP MLD809may have a MAC address that is different and used by application programs where the data traffic is split up among non-AP STA1818, non-AP STA2820, and non-AP STA3822.

The STA504is a non-AP STA1818, non-AP STA2820, or non-AP STA3822, in accordance with some embodiments. The non-AP STA1818, non-AP STA2820, and non-AP STA3822may operate as if they are associated with a BSS of AP1830, AP2832, or AP3834, respectively, over link 1804.1, link 2804.2, and link 3804.3, respectively.

A Multi-link device such as ML logical entity 1806or ML logical entity 2807, is a logical entity that contains one or more STAs814,816. The ML logical entity 1806and ML logical entity 2807each has one MAC data service interface and primitives to the logical link control (LLC) and a single address associated with the interface, which can be used to communicate on the DSM812. Multi-link logical entity allows STAs814,816within the multi-link logical entity to have the same MAC address. In some embodiments a same MAC address is used for application layers and a different MAC address is used per link.

In infrastructure framework, AP MLD808, includes APs830,832,834, on one side, and non-AP MLD809, which includes non-APs STAs818,820,822on the other side.

ML AP device (AP MLD): is a ML logical entity, where each STA within the multi-link logical entity is an EHT AP502, in accordance with some embodiments. ML non-AP device (non-AP MLD) A multi-link logical entity, where each STA within the multi-link logical entity is a non-AP EHT STA504. AP1830, AP2832, and AP3834may be operating on different bands and there may be fewer or more APs. There may be fewer or more STAs as part of the non-AP MLD809.

In some embodiments the AP MLD808is termed an AP MLD or MLD. In some embodiments non-AP MLD809is termed a MLD or a non-AP MLD. Each AP (e.g., AP1830, AP2832, and AP3834) of the MLD sends a beacon frame that includes: a description of its capabilities, operation elements, a basic description of the other AP of the same MLD that are collocated, which may be a report in a Reduced Neighbor Report element or another element such as a basic multi-link element. AP1830, AP2832, and AP3834transmitting information about the other APs in beacons and probe response frames enables STAs of non-AP MLDs to discover the APs of the AP MLD.

In a Wi-Fi network or IEEE 802.11 network, “channel switching” refers to a method where the AP502in an infrastructure networks or Group Owner (GO) in peer-to-peer networks determines to transition from a current channel to a new target channel. The AP502may determine to switch channels for lots of reasons such as interference.

During channel switching, the clients such as STAs504and legacy devices506that are associated with the AP502on an old channel or original channel often remain associated with the AP502on the new channel. The clients are expected to move alongside the GO or AP502and maintain uninterrupted communication as if they were still operating on the original channel. The continues uninterrupted communication includes preserving sequence numbers of PPDUs and other relevant contexts.

However, Wi-Fi or IEEE 802.11 bands do not uniformly follow the same rules in terms of the allowed formats and bandwidths that clients can use. For example, in the 2.4 GHz band, a client can utilize the HT format with a bandwidth of 20/40 MHz. In the 5 GHz band, a client can use HT/VHT and HE formats with bandwidths of 20/40/80/160 MHz. In the 6 GHz band, a client is mandated to use HE or EHT (Wi-Fi-7) and can transmit frames using a 320 MHz bandwidth.

Clients associate with APs502. During the association process, the clients and APs502exchange capabilities through an association request frame and an association response frame. The AP502may move to another band or target channel and the AP502does not know the capabilities of its clients in the target channel. The AP502uses the lowest common denominator of client capabilities to communicate with the clients on the target channel, which may be using an HT format, which, often, fails to fully exploit the enhanced potential of the new target band.

IEEE 802.11 standards often permit STAs504and APs502to use channels when the STA504or AP502transitions to a new channel. The STA504or AP502often has no information regarding the usage or the channel before transitioning from another channel or link. Additionally, the STA504or AP502may wake up on a channel and have no information regarding the channel usage before waking up.

In some examples, a STA504or AP502may have acquired a TxOP on a channel and another STA504or AP502may transition to the channel or wakeup on the channel. The STA504or AP502arriving or waking up on the channel may miss or not detect the preamble of a PPDU being transmitted. In some examples, the STA504or AP502may rely on energy detection (ED) to determine if the channel is free. In some examples, IEEE 802.11 standards and/or WiFi standards require a lower ED level for determining if the channel is free, but this is potentially still higher than the noise floor and, in some examples, up to 30 dB higher than the noise floor.

Thus, a STA504or AP502can have its receiver receiving signals with a noise floor that is up to 30 dB above the traditional noise floor, while the clear channel assessment (CCA) does not indicate busy. Additionally, the NAV of the STA504or AP502is not set since the STA504or AP502just transitioned to the channel or woke up on the channel and missed the preamble of the PPDU transmitted by another STA504or AP502.

The STA504or AP502can start transmitting if it is performing enhanced distributed channel access (EDCA) and gains access to the medium. The STA504or AP502may also be addressed an RTS frame and should respond with CTS.

Additionally, another STA504or AP502may be receiving on the channel the STA504or AP502switched to or woke up on. The STA504or AP502may begin to transmit on the channel. The another STA504or AP502may experience increased noise on the channel they are transmitting on or receiving on. A STA504or AP502may use an encoding rate for a PPDU based on previous transmissions before the new interference. The interference is potentially up to 30 dB above the noise floor. The initiator of the TxOP will send a PPDU with a rate that, based on previous transmissions, is selected by the rate adaptation mechanism.

A technical problem is how to adjust for the added interference on the channel. The technical problem is addressed by the STA504or AP502receiving the RTS to include noise levels of the channel in the CTS response. In this way, the sender of the RTS is provided with fresher information regarding the channel and the additional interference caused by the STA504or AP502that transitioned to or woke up on the channel and began transmitting based on ED levels above the noise level. The sender of the RTS may then adjust the encoding rate from previous transmissions that were not suffering from added interference where the new rate for encoding PPDUs will like be lower because of the information provided by the CTS. This may prevent the loss of the entire PPDU (that can be up to 5 ms) after CTS response because the transmitter of the RTS will be aware of the greater interference.

FIG.9illustrates a STA504switching channels, in accordance with some examples. The STA504switches from channel 1902to channel 2904or awakens on channel 2904after a period of sleep. The STA504misses the preamble906of a PPDU908. The STA504contends for channel 2 and/or performs EDCA914on channel 2904with an ED1002that is above the noise level, e.g., energy detect level1004. The ED1002may be the energy detect level1004as disclosed in conjunction withFIG.10. The STA504missed decoding the preamble906so it does not or cannot decode the PPDU908. The STA504transmits912on channel 2904a frame. The frame (not illustrated) causes another STA504(not illustrated) to experience greater interference or noise on channel 2904than it was before the STA504transmits912on channel 2904. The time911progresses from the left side of the figure to the right side of the figure.

FIG.10illustrates an energy detect level, in accordance with some embodiments. The noise level1006is a level defined for noise or interference. The energy detect level1004is above the noise level1006by 1 to 50 dB. In some embodiments, the energy detect level1004is 30 dB above the noise level1006. In some embodiments, the noise level1006is equal to or approximately-90 dB.

FIG.11illustrates a clear to send1100frame, in accordance with some embodiments. The number of octets1110for the fields is indicated below the field. The clear to send (CTS)1100includes the following fields: a frame control1102, a duration1104, a receiver address (RA)1106, and a frame check sequence (FCS)1108. In accordance with some embodiments, the link adaptation information1112is encoded in one or more of the fields. The link adaptation information1112may be encoded in one or more reserviced bits of the fields. The link adaptation information1112may be encoded by modifying one or more of the encodings of the fields. The link adaptation information1112may be encoded in one or more reserved bits of a service field.

FIG.12illustrates an alternative frame1200, in accordance with some embodiments. The alternative frame1200may be an alternative clear to send1202, which includes link adaptation information1204. For example, the new clear to send1202has a field and/or one or more bits for encoding link adaptation information1204. Link adaptation information1204may be the same or similar as link adaptation information1112or may be different.

The link adaptation information1204provides information regarding the channel state before the reception of, referring toFIG.13, the RTS1312frame addressed to STA B1303. The AP1304can use the link adaptation information1204to help link adaptation or rate selection of following frame1330or PPDU in the same TxOP1334.

The alternative frame1200may carry a CTS frame (e.g., CTS1100) with a qualify of service null frame with an aggregated (A)-control, which may include a subfield for the link adaptation information1112,1204. The link adaptation information1112,1204may be a QoS field such as a QoS information field.

The alternative frame1200may be a new CTS frame with a field or subfield for the link adaptation information1204. The CTS1202may be used to set the network allocation vector (NAV). In some embodiments, the alternative frame1200may be a buffer status report poll (BSRP) frame or another type of frame that acts as the CTS frame (to set the NAV) and carries the link adaptation information1204. In some embodiments, the alternative frame1200may be a management frame as disclosed in the IEEE 802.11 standard with one or more fields used to represent the link adaptation information1204.

FIG.13illustrates a method1300for link adaptation reporting, in accordance with some embodiments. The STA A1302, STA B1303, and AP1304may be a STA504, AP502, a non-AP STA of a non-AP MLD809, and/or an AP of a AP MLD808.

The method1300begins with STA A1302operating1306on channel one902. The method1300continues at operation1308with STA A1302switching to or waking up on channel two904, e.g., switches channel910which may be in the middle of a PPDU908being transmitted by the AP1304or STA B1303. The method1300continues with AP1304and STA B1303participating in previous TxOPs1315. The method1300continues with STA A1302performing EDCA1310, e.g., performs EDCA914. The method1300continues at operation1318with STA A1302, after gaining access to channel two904, transmitting frame1316to another STA (not illustrated).

The method1300continues at operation1333with STA B1303measuring the energy levels or observing the channel status of channel two904for one of the following durations: a reduced interframe space (RIFS) before the RTS, a short interframe space (SIFS) before the RTS, a point coordinated function (PCF) interframe space (PIFS) before the RTS, a distributed coordinated function interframe space (DIFS), an arbitration interframe space (AIFS), an extended interframe space (EIFS), and a link adaptation information interframe space. Operation1333may extend into the reception of the RTS1312frame and after the reception of the RTS1312frame up until the time of the transmission of the CTS1320frame.

The method1300continues at operation1314with the AP1304transmitting an RTS1312frame to the STA B1303. The method1300continues with STA B, after a short interframe space (SIFS)1332or another time period, transmitting1322a CTS1320frame to the AP1304. The STA B1303encodes the CTS1320frame or an alternative frame1200to include link adaptation information1112,1204that is based on the results of operation1333. The AP1304obtains a TxOP1334.

In some embodiments, link adaptation information1112,1204is the received signal strength indicator (RSSI) or Signal to Interference plus Noise Ratio (SINR) of the RTS1312, which could be another type of initial control frame, that was received by the STA B1303, or the transmit power used by STA B1303to send the CTS1320frame. This enables the AP1304that sent the RTS1312frame (or initial control frame) to estimate the link budget of the channel two904.

The link adaptation information1112,1204can also be the difference between the RSSI value measured on this RTS1312frame in this TxOP1334, compared with an average of RSSI values based on RTS frames received in previous TxOPs1315either the immediately preceding TxOP, or averaged over N immediately preceding TxOP1315.

In some embodiments, the link adaptation information is a difference between a first noise floor level measured before receiving the RTS1312frame and a second noise floor level measured before receiving another RTS in a previous TxOP1315, which started the previous TXoP1315and where the STA B1303was the responder to the RTS.

In some examples, the link adaptation information1112,1204is a change in RSSI during reception of the RTS1312frame, which informs the AP1304that interference might have occurred during the reception of the RTS1312frame. The link adaptation information1112,1204could indicate a rise in the RSSI measured from received signals in a short period of time, or could be a mean with a variance of RSSI during the reception of the RTS1312frame.

The method1300continues at operation1326where the AP1304determines an encoding rate (or coding rate) to use for the frame1330based on the link adaptation information1112,1204, included in the CTS1320frame. The method1300continues with the AP1304encoding and transmitting1328the frame1330based on the link adaptation information1112,1204.

The link adaptation information1112,1204may be one or more of the following. A Signal to Interference plus Noise Ratio (SINR) of the noise floor measured right before the reception of the RTS frame that elicited the CTS response. Receiving the link adaptation information1112permits the STA, e.g., AP1304, that sent the RTS, e.g., RTS1312, to estimate the level of interference that is added in this TxOP1334compared to previous TxOPs1315.

In some examples, a difference between the noise floor level measured right before the RTS frame, e.g., RTS1312, was received such as an observation period1332of PIFS before the RTS1312, compared to the noise floor level measured right before RTS frame received in previous TxOPs1315where the STA B1303was a TxOP responder and averaged over these different TxOPs.

In some embodiments, STA B1303can send updates periodically if the transmissions are ongoing, or a history of previous SINR levels of previous exchanges. This could be any exchanges that happened within a fixed, relevant, time interval where the time is fixed or negotiated.

The method1300may include one or more additional instructions. The method1300may be performed in a different order. One or more of the operations of method1300may be optional.

FIG.14illustrates a method1400for link adaptation reporting, in accordance with some embodiments. The method1400begins at operation1402with decoding, from an AP, a RTS frame. For example, STA B1303decodes RTS1312from AP1304. The method1400continues at operation1404with determining link adaptation information. For example, the STA B1303determines link adaptation information1112,1204at1333.

The method1400continues at operation1406with encoding, for transmission to the AP, a CTS frame, the CTS frame comprising an indication of the link adaptation information. For example, the STA B1303encodes the CTS1320to include an indication of link adaptation information1112,1204, and transmit the CTS1320frame to the AP1304.

The method1400may be performed by an apparatus for a STA504, an apparatus of a non-AP MLD809, an apparatus of an AP502, or an apparatus of an AP MLD808, and/or another device or apparatus disclosed herein. The method1400may include one or more additional instructions. The method1400may be performed in a different order. One or more of the operations of method1400may be optional.

FIG.15illustrates a method1500for link adaptation reporting, in accordance with some embodiments. The method1500begins at operation1502with encoding, for transmission to a STA, a RTS frame. For example, AP1304encodes the RTS1312frame for transmission to the STA B1303.

The method1500continues at operation1504with decoding, from the STA, a CTS frame, the CTS frame comprising an indication of the link adaptation information. For example, the AP1304decodes the CTS1320frame from the STA B1303. The method1500continues at operation1506with determining a coding rate for a physical layer protocol data unit (PPDU) based on the link adaptation information. For example, the AP1304determines a coding rate at operation1326.

The method1500continues at operation1508with encoding, for transmission to the STA, the PPDU in accordance with the coding rate. For example, the AP1304encodes for transmission the frame1330.

The method1500may be performed by an apparatus for a STA504, an apparatus of a non-AP MLD809, an apparatus of an AP502, or an apparatus of an AP MLD808, and/or another device or apparatus disclosed herein. The method1500may include one or more additional instructions. The method1500may be performed in a different order. One or more of the operations of method1500may be optional.