Preemption of low latency traffic during TXOP using preemption request control frames

Abstract

An access point station configured for ultra high reliability communications in a wireless local area network may receive low latency traffic during TXOP through an initial frame encoded to indicate whether preemption for LL traffic is enabled during TXOP. When preemption of LL traffic is enabled during the TXOP, the AP may encode the DL PPDU for transmission within the TXOP. The DL PPDU may be transmitted with an xIFS therebetween. Each DL PPDU may indicate whether an xIFS following the DL PPDU is enabled for preemption. When a signal including at least the L-STF is detected within one of the xIFSs enabled for preemption, the AP may suspend subsequent transmission of at least the next DL PPDU and may attempt to decode a frame including the L-STF to determine whether the frame is a preemption request frame. When it is determined that the frame is a preemption request frame, the AP may trigger the STA to send LL traffic to the AP.

Description

Background Art

[0001] For wireless local area networks (WLANs), communicating time-sensitive traffic, sometimes called low-latency (LL) traffic, is challenging for many reasons. For example, contention for the wireless medium. Since WLANs typically use a shared medium for all clients, contention can occur when multiple clients try to communicate at the same time, which introduces jitter and latency. This is particularly problematic for time-sensitive traffic like voice and video. The hidden node problem (i.e., when nodes are not in range of each other but in range of an access point, they cannot sense when the other is transmitting) can cause collisions and retransmissions, which can disrupt low-latency communications. Channel errors and retransmissions (i.e., the wireless medium is subject to interference and noise, which can corrupt packets and force retransmissions) add latency and jitter. Packet loss (i.e., lost or corrupted packets require retransmissions) adds latency, and time-sensitive traffic like voice and video may not be able to wait for retransmissions. An overloaded network (i.e., too many clients competing for bandwidth on the WLAN) may make it difficult to provide consistent low-latency service, especially for bandwidth-intensive traffic like video. Roaming between APs (i.e., when a client roams between APs) may introduce latency while the network reconnects the client to the new AP. Power saving operations (i.e., some power saving mechanisms, such as PS-Poll) may add significant latency to individual packet transmissions.

[0002] Therefore, there is a general need to improve LL communications in WLANs. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Figure 1 is a block diagram of a radio architecture according to some embodiments.

[0004] Figure 2 The diagram illustrates a method for Figure 1 Front-end module circuits in radio architectures.

[0005] Figure 3 The diagram illustrates a method for Figure 1 Radio IC circuits in the radio architecture.

[0006] Figure 4 The diagram illustrates a method for Figure 1 Baseband processing circuits in the radio architecture of .

[0007] Figure 5 A WLAN according to some embodiments is illustrated.

[0008] Figure 6Illustrated is preemption of low latency (LL) traffic during a transmission opportunity (TXOP) in accordance with some embodiments.

[0009] Fig. 7A A preemption request control frame is illustrated in accordance with some embodiments.

[0010] Figure 7B A preemption request control frame according to some other embodiments is illustrated.

[0011] Figure 7C Illustrated is a short feedback MAC frame format for a preemption request frame according to some embodiments.

[0012] Fig.7D Illustrated is a frame control and feedback time field according to some embodiments.

[0013] Figure 8 A wireless communication device in accordance with some embodiments is illustrated.

[0014] Fig. 9 is a process of receiving low latency (LL) traffic by an access point station (AP) configured for ultra high reliability (UHR) communications in a wireless local area network (WLAN) according to some embodiments. DETAILED DESCRIPTION

[0015] The following description and accompanying drawings fully illustrate specific embodiments to enable those skilled in the art to implement them. Other embodiments may include structural, logical, electrical, process, and other changes. Parts and features of some embodiments may be included in other embodiments, or replace parts and features of other embodiments. The embodiments recorded in the claims cover all available equivalents of these claims.

[0016] Embodiments described herein relate to an access point station (AP) configured for ultra-high reliability (UHR) communications in a wireless local area network (WLAN); the access point station (AP) can receive low-latency (i.e., time-sensitive) traffic during a transmission opportunity (TXOP) by transmitting an initial frame that is encoded to indicate whether preemption for low-latency (LL) traffic is enabled during the TXOP. When preemption for LL traffic is enabled during the TXOP, the AP can encode a downlink (DL) physical layer protocol data unit (PPDU) for transmission within the TXOP. The DL PPDU can be sent with an extended short interframe spacing (xIFS) therebetween. Each DL PPDU can indicate whether the xIFS following the DL PPDU has been enabled for preemption. When a signal including at least a legacy short-training field (L-STF) is detected in one of the xIFSs enabled for preemption, the AP may suspend subsequent transmission of at least the next DL PPDU and may attempt to decode a frame including the L-STF to determine whether the frame is a preemption request frame. When it is determined that the frame is a preemption request frame, the AP may trigger a station (STA) to send LL traffic to the AP. These embodiments and other embodiments are described in more detail herein.

[0017] Figure 1 1 is a block diagram of a radio architecture 100 according to some embodiments. The radio architecture 100 may include a radio front-end module (FEM) circuit 104, a radio IC circuit 106, and a baseband processing circuit 108. As shown, the radio architecture 100 includes both a wireless local area network (WLAN) function and a Bluetooth (BT) function, although the embodiments are not limited thereto. In the present disclosure, "WLAN" and "Wi-Fi" are used interchangeably.

[0018] The FEM circuit 104 may include a WLAN or Wi-Fi FEM circuit 104A and a Bluetooth (BT) FEM circuit 104B. The WLAN FEM circuit 104A may include a receive signal path including circuitry configured to operate on WLAN RF signals received from one or more antennas 101, amplify the received signals, and provide an amplified version of the received signals to the WLAN radio IC circuit 106A for further processing. The BT FEM circuit 104B may include a receive signal path including circuitry configured to operate on BT RF signals received from one or more antennas 101, amplify the received signals, and provide an amplified version of the received signals to the BT radio IC circuit 106B for further processing. The FEM circuit 104A may also include a transmit signal path including circuitry configured to amplify WLAN signals provided by the radio IC circuit 106A for wireless transmission by the one or more antennas 101. Additionally, FEM circuitry 104B may also include a transmit signal path that may include circuitry configured to amplify BT signals provided by radio IC circuitry 106B for wireless transmission by one or more antennas. Figure 1 In the embodiment, although FEM circuit 104A and FEM circuit 104B are shown as being distinguished from each other, the embodiments are not limited thereto and include within their scope the use of a FEM (not shown) that includes transmit paths and / or receive paths for both WLAN and BT signals, or the use of one or more FEM circuits in which at least some of the FEM circuits share transmit and / or receive signal paths for both WLAN and BT signals.

[0019] As shown, the radio IC circuit 106 may include a WLAN radio IC circuit 106A and a BT radio IC circuit 106B. The WLAN radio IC circuit 106A may include a receive signal path that may include circuitry to down-convert a WLAN RF signal received from the FEM circuit 104A and provide a baseband signal to the WLAN baseband processing circuit 108A. The BT radio IC circuit 106B may in turn include a receive signal path that may include circuitry to down-convert a BT RF signal received from the FEM circuit 104B and provide a baseband signal to the BT baseband processing circuit 108B. The WLAN radio IC circuit 106A may also include a transmit signal path that may include circuitry to up-convert a WLAN baseband signal provided by the WLAN baseband processing circuit 108A and provide a WLAN RF output signal to the FEM circuit 104A for subsequent wireless transmission by one or more antennas 101. The BT radio IC circuit 106B may also include a transmit signal path that may include circuitry to up-convert the BT baseband signal provided by the BT baseband processing circuit 108B and provide a BT RF output signal to the FEM circuit 104B for subsequent wireless transmission by one or more antennas 101. Figure 1 In the embodiment of the present invention, although the radio IC circuits 106A and 106B are shown as being distinguished from each other, the embodiments are not limited to this and include within their scope the use of a radio IC circuit (not shown) that includes a transmit signal path and / or receive signal path for both WLAN and BT signals, or the use of one or more radio IC circuits in which at least some of the radio IC circuits share transmit and / or receive signal paths for both WLAN and BT signals.

[0020] The baseband processing circuit 108 may include a WLAN baseband processing circuit 108A and a BT baseband processing circuit 108B. The WLAN baseband processing circuit 108A may include a memory, such as a set of RAM arrays in a fast Fourier transform or inverse fast Fourier transform block (not shown) of the WLAN baseband processing circuit 108A. Each of the WLAN baseband circuit 108A and the BT baseband circuit 108B may also include one or more processors and control logic to process signals received from the corresponding WLAN or BT receive signal path of the radio IC circuit 106, and also generate corresponding WLAN or BT baseband signals for the transmit signal path of the radio IC circuit 106. Each of the baseband processing circuits 108A and 108B may also include a physical layer (PHY) and a medium access control layer (MAC) circuit, and may also interface with the application processor 111 to generate and process baseband signals and control the operation of the radio IC circuit 106.

[0021] Still reference Figure 1 According to the illustrated embodiment, the WLAN-BT coexistence circuit 113 may include logic to provide an interface between the WLAN baseband circuit 108A and the BT baseband circuit 108B to enable use cases requiring WLAN and BT coexistence. In addition, a switch 103 may be provided between the WLAN FEM circuit 104A and the BT FEM circuit 104B to allow switching between WLAN and BT radios as required by the application. In addition, while the antenna 101 is depicted as being connected to the WLAN FEM circuit 104A and the BT FEM circuit 104B, respectively, embodiments include within their scope sharing one or more antennas between the WLAN and BT FEMs, or providing more than one antenna connected to each of the FEM circuits 104A or 104B.

[0022] In some embodiments, the front end module circuit 104, the radio IC circuit 106, and the baseband processing circuit 108 may be provided on a single radio card, such as the wireless radio card 102. In some other embodiments, one or more antennas 101, the FEM circuit 104, and the radio IC circuit 106 may be provided on a single radio card. In some other embodiments, the radio IC circuit 106 and the baseband processing circuit 108 may be provided on a single chip or integrated circuit (IC), such as IC 112.

[0023] In some embodiments, wireless radio card 102 may include a WLAN radio card and may be configured for Wi-Fi communications, although the scope of the embodiments is not limited in this respect. In some of these embodiments, radio architecture 100 may be configured to receive and transmit orthogonal frequency division multiplexed (OFDM) or orthogonal frequency division multiple access (OFDMA) communication signals over a multi-carrier communication channel. OFDM or OFDMA signals may include multiple orthogonal subcarriers.

[0024] In some of these multi-carrier embodiments, the radio architecture 100 may be part of a Wi-Fi communication station (STA), such as a wireless access point (AP), a base station, or a mobile device including a Wi-Fi device. In some of these embodiments, the radio architecture 100 may be configured to send and receive signals in accordance with a specific communication standard and / or protocol, such as any standard of the Institute of Electrical and Electronics Engineers (IEEE), including IEEE 802.11n-2009, IEEE 802.11-2012, IEEE 802.11-2016, IEEE 802.11ac, IEEE 802.11ax, and / or IEEE P802.11be standards and / or specifications proposed for WLAN, although the scope of the embodiments is not limited in this regard. The radio architecture 100 may also be adapted to send and / or receive communications in accordance with other technologies and standards.

[0025] In some embodiments, the radio architecture 100 may be configured for high-efficiency (HE) Wi-Fi (HEW) communications in accordance with the IEEE 802.11ax standard. In some embodiments, the radio architecture 100 may be configured for extremely high throughput (EHT) communications in accordance with the IEEE 802.11be standard. In some embodiments, the radio architecture 100 may be configured for ultra-high reliability (UHR) communications in accordance with IEEE 802.11 (e.g., WiFi 8). In these embodiments, the radio architecture 100 may be configured to communicate in accordance with OFDMA technology, although the scope of the embodiments is not limited in this respect. In some embodiments, the radio architecture 100 may be configured for next generation vehicle-to-everything (NGV) communications in accordance with the IEEE 802.11bd standard, and one or more stations including the AP 502 may be next generation vehicle-to-everything (NGV) stations (STAs).

[0026] In some other embodiments, the radio architecture 100 may be configured to send and receive signals sent using one or more other modulation techniques, such as spread spectrum modulation (e.g., direct sequence code division multiple access (DS-CDMA) and / or frequency hopping code division multiple access (FH-CDMA)), time-division multiplexing (TDM) modulation, and / or frequency-division multiplexing (FDM) modulation, although the scope of the embodiments is not limited in this respect.

[0027] In some embodiments, Figure 1 As further shown, the BT baseband circuit 108B may comply with a Bluetooth (BT) connectivity standard, such as Bluetooth, Bluetooth 4.0, or Bluetooth 5.0, or any other iteration of the Bluetooth standard. Figure 1 In the illustrated embodiments including BT functionality, the radio architecture 100 may be configured to establish a BT synchronous connection oriented (SCO) link and / or a BT low energy (BT LE) link. In some embodiments including functionality, the radio architecture 100 may 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 including BT functionality, the radio architecture may be configured to participate in BT asynchronous connection-less (ACL) communications, although the scope of the embodiments is not limited in this respect. In some embodiments, as Figure 1 As shown, the functionality of a BT radio card and a WLAN radio card may be combined on a single wireless radio card, such as a single wireless radio card 102, although embodiments are not so limited and include separate WLAN and BT radio cards within their scope.

[0028] In some embodiments, the radio architecture 100 may include other radio cards, such as a cellular radio card configured for cellular (e.g., 3GPP such as LTE, LTE Advanced, or 5G communications).

[0029] In some IEEE 802.11 embodiments, the radio architecture 100 can be configured for communication over a variety of channel bandwidths, including bandwidths with center frequencies of about 900 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 continuous bandwidth), or 80+80 MHz (160 MHz) (with non-continuous bandwidth). In some embodiments, a 320 MHz channel bandwidth can be used. However, the scope of the embodiments is not limited to the above center frequencies.

[0030] Figure 2 FIG. 2 shows a FEM circuit 200 according to some embodiments. The FEM circuit 200 is suitable for use as a WLAN and / or BTFEM circuit 104A / 104B ( Figure 1 ) is an example of a circuit, although other circuit configurations may also be appropriate.

[0031] In some embodiments, the FEM circuit 200 may include a TX / RX switch 202 to switch between transmit mode and receive mode operation. The FEM circuit 200 may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuit 200 may include a low-noise amplifier (LNA) 206 to amplify the received RF signal 203 and provide an amplified received RF signal 207 as an output (e.g., provided to the radio IC circuit 106 ( Figure 1 )). The transmit signal path of circuit 200 may include a power amplifier (PA) to amplify an input RF signal 209 (e.g., provided by radio IC circuit 106), and one or more filters 212, such as a band-pass filter (BPF), a low-pass filter (LPF), or other types of filters, to generate an RF signal 215 for subsequent transmission (e.g., by antenna 101 ( Figure 1 ) is sent in one or more ).

[0032] In some dual-mode embodiments for Wi-Fi communications, the FEM circuit 200 may be configured to operate in either the 2.4 GHz spectrum or the 5 GHz spectrum. In these embodiments, the receive signal path of the FEM circuit 200 may include a receive signal path duplexer 204 to separate the signals from each spectrum, and provide a separate LNA 206 for each spectrum, as shown. In these embodiments, the transmit signal path of the FEM circuit 200 may also include a power amplifier 210 and a filter 212, such as a BPF, LPF, or another type of filter for each spectrum, and a transmit signal path duplexer 214 to provide the signal of one of the different spectrums onto a single transmit path for subsequent transmission by the antenna 101 ( Figure 1 ) in one or more of the transmissions. In some embodiments, BT communications may utilize a 2.4 GHZ signal path and may utilize the same FEM circuit 200 as used for WLAN communications.

[0033] Figure 3 1 and 2. The radio IC circuit 300 is illustrated in accordance with some embodiments. The radio IC circuit 300 is suitable for use as a WLAN or BT radio IC circuit 106A / 106B ( Figure 1 ) is an example of a circuit, although other circuit configurations may also be appropriate.

[0034] In some embodiments, the radio IC circuit 300 may include a receive signal path and a transmit signal path. The receive signal path of the radio IC circuit 300 may include at least a mixer circuit 302 (e.g., a down-conversion mixer circuit), an amplifier circuit 306, and a filter circuit 308. The transmit signal path of the radio IC circuit 300 may include at least a filter circuit 312 and a mixer circuit 314 (e.g., an up-conversion mixer circuit). The radio IC circuit 300 may also include a synthesizer circuit 304 for synthesizing a frequency 305 for use by the mixer circuit 302 and the mixer circuit 314. According to some embodiments, the mixer circuits 302 and / or 314 may each be configured to provide a direct conversion function. Compared to a standard superheterodyne mixer circuit, the latter type of circuit presents a much simpler architecture and any flicker noise introduced therefrom may be mitigated, for example, by using OFDM modulation. Figure 3 Only a simplified version of the radio IC circuit is illustrated, and although not shown, embodiments may include that each of the depicted circuits may include more than one component. For example, mixer circuits 320 and / or 314 may each include one or more mixers, and filter circuits 308 and / or 312 may each include one or more filters, such as one or more BPFs and / or LPFs, as required by the application. For example, when the mixer circuits are of the direct conversion type, they may each include two or more mixers.

[0035] In some embodiments, mixer circuit 302 may be configured to generate a synthesized frequency 305 from FEM circuit 104 based on the synthesized frequency 305 provided by synthesizer circuit 304. Figure 1 ) down-converts the received RF signal 207. The amplifier circuit 306 may be configured to amplify the down-converted signal, and the filter circuit 308 may include an LPF configured to remove unwanted signals from the down-converted signal to generate an output baseband signal 307. The output baseband signal 307 may be provided to the baseband processing circuit 108 ( Figure 1 ) for further processing. In some embodiments, output baseband signal 307 may be a zero frequency baseband signal, although this is not a necessary requirement. In some embodiments, mixer circuit 302 may include a passive mixer, although the scope of the embodiments is not limited in this respect.

[0036] In some embodiments, mixer circuit 314 may be configured to up-convert input baseband signal 311 based on synthesized frequency 305 provided by synthesizer circuit 304 to generate RF output signal 209 for FEM circuit 104. Baseband signal 311 may be provided by baseband processing circuit 108 and may be filtered by filter circuit 312. Filter circuit 312 may include an LPF or a BPF, although the scope of the embodiments is not limited in this respect.

[0037] In some embodiments, mixer circuit 302 and mixer circuit 314 may each include two or more mixers and may be arranged for quadrature down-conversion and / or up-conversion, respectively, with the aid of synthesizer circuit 304. In some embodiments, mixer circuit 302 and mixer circuit 314 may each include two or more mixers, each mixer being configured for image rejection (e.g., Hartley image rejection). In some embodiments, mixer circuit 302 and mixer circuit 314 may each be arranged for direct down-conversion and / or direct up-conversion, respectively. In some embodiments, mixer circuit 302 and mixer circuit 314 may be configured for superheterodyne operation, although this is not a necessary requirement.

[0038] According to one embodiment, mixing circuit 302 may include: quadrature passive mixers (eg, for in-phase (I) and quadrature-phase (Q) paths). In such an embodiment, Figure 3 The RF input signal 207 may be down converted to provide I and Q baseband output signals to be sent to a baseband processor.

[0039] The quadrature passive mixers can be driven by zero-degree and ninety-degree time-varying LO switching signals provided by a quadrature circuit that can be configured to receive LO frequencies (f LO), such as synthesizer circuit 304 ( Figure 3 ) 305. In some embodiments, the LO frequency may be the carrier frequency, while in other embodiments, the LO frequency may be some fraction of the carrier frequency (e.g., one-half the carrier frequency, one-third the carrier frequency). In some embodiments, the zero-degree and ninety-degree time-varying switching signals may be generated by a synthesizer, although the scope of the embodiments is not limited in this respect.

[0040] In some embodiments, the LO signal can vary in duty cycle (the percentage of a cycle that the LO signal is high) and / or offset (the difference between the start points of the cycle). In some embodiments, the LO signal can have a 25% duty cycle and a 50% offset. In some embodiments, each branch of the mixer circuit (e.g., the in-phase (I) and quadrature-phase (Q) paths) can operate at a 25% duty cycle, which can result in a significant reduction in power consumption.

[0041] RF input signal 207 ( Figure 2 ) may include balanced signals, although the scope of the embodiments is not limited in this respect. The I and Q baseband output signals may be provided to a low noise amplifier, such as amplifier circuit 306 ( Figure 3 ) or filter circuit 308 ( Figure 3 ).

[0042] In some embodiments, output baseband signal 307 and input baseband signal 311 may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternative embodiments, output baseband signal 307 and input baseband signal 311 may be digital baseband signals. In these alternative embodiments, the radio IC circuit may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuits.

[0043] In some dual-mode embodiments, separate radio IC circuits may be provided to process signals for each spectrum, or for other spectrums not mentioned herein, although the scope of the embodiments is not limited in this respect.

[0044] In some embodiments, synthesizer circuit 304 may 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 appropriate. For example, synthesizer circuit 304 may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase-locked loop with a frequency divider. According to some embodiments, synthesizer circuit 304 may include a digital synthesizer circuit. One advantage of using a digital synthesizer circuit is that, while it may still include some analog components, its footprint may be much reduced than that of an analog synthesizer circuit. In some embodiments, the frequency input to synthesizer circuit 304 may be provided by a voltage-controlled oscillator (VCO), although this is not a necessary requirement. Depending on the desired output frequency 305, the divider control input may be provided by baseband processing circuit 108 ( Figure 1 ) or application processor 111 ( Figure 1 ) is provided. In some embodiments, the divider control input (eg, N) may be determined from a lookup table (eg, within a Wi-Fi card) based on the channel number and channel center frequency determined or indicated by the application processor 111.

[0045] In some embodiments, synthesizer circuit 304 may be configured to generate a carrier frequency as output frequency 305, while in other embodiments, output frequency 305 may be a fraction of the carrier frequency (e.g., half the carrier frequency, one third the carrier frequency). In some embodiments, output frequency 305 may be the LO frequency (f LO ).

[0046] Figure 4 FIG. 4 is a functional block diagram of a baseband processing circuit 400 according to some embodiments. The baseband processing circuit 400 is a circuit that can be used as the baseband processing circuit 108 ( Figure 1 ) is an example of a circuit that may be used to process signals received by radio IC circuit 106 ( Figure 1 ) and a transmit baseband processor (TX BBP) 404 for generating a transmit baseband signal 311 for the radio IC circuit 106. The baseband processing circuit 400 may also include control logic 406 for coordinating the operation of the baseband processing circuit 400.

[0047] In some embodiments (e.g., when analog baseband signals are exchanged between baseband processing circuit 400 and radio IC circuit 106), baseband processing circuit 400 may include ADC 410 to convert analog baseband signals received from radio IC circuit 106 into digital baseband signals for processing by RX BBP 402. In these embodiments, baseband processing circuit 400 may also include DAC 412 to convert digital baseband signals from TX BBP 404 into analog baseband signals.

[0048] In some embodiments where OFDM or OFDMA signals are transmitted, for example, by baseband processor 108A, transmit baseband processor 404 may be configured to generate an OFDM or OFDMA signal suitable for transmission by performing an inverse fast Fourier transform (IFFT). Receive baseband processor 402 may be configured to process received OFDM or OFDMA signals by performing an FFT. In some embodiments, receive baseband processor 402 may be configured to detect the presence of OFDM or OFDMA signals by performing autocorrelation to detect preambles such as short preambles, and to detect the presence of OFDM or OFDMA signals by performing cross-correlation to detect long preambles. These preambles may be part of a predetermined frame structure for Wi-Fi communications.

[0049] Return to reference Figure 1 In some embodiments, antenna 101 ( Figure 1 ) may each include one or more directional or omnidirectional antennas, such as dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of RF signals. In some multiple-input multiple-output (MIMO) embodiments, the antennas may be effectively separated to exploit spatial diversity and the different channel characteristics that may be generated. Antennas 101 may each include a set of phased array antennas, although embodiments are not limited thereto.

[0050] Although the radio architecture 100 is shown as having several separate functional elements, one or more of these functional elements may be combined and may be implemented by a combination of software-configured elements (e.g., processing elements including digital signal processors (DSPs)) and / or other hardware elements. For example, some elements may include 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 circuits for performing at least the functions described herein. In some embodiments, a functional element may refer to one or more processes operating on one or more processing elements.

[0051] Figure 5 A WLAN 500 according to some embodiments is illustrated. The WLAN 500 may include a basis service set (BSS), which may include an access point (AP) 502 (which may be an AP), a plurality of stations 504, and a plurality of legacy (e.g., IEEE 802.11n / ac / ax) devices 506. In some embodiments, the WLAN 500 may be configured for extremely high throughput (EHT) communications in accordance with the IEEE 802.11be standard, and one or more stations including the AP 502 and the station 504 may be EHT STAs. In some embodiments, the WLAN 500 may be configured for ultra-high rate (UHR) communications in accordance with one of the IEEE 802.11 standards or draft standards, and one or more stations including the AP 502 and the station 504 may be UHR and / or UHR+STAs.

[0052] In some embodiments, the WLAN 500 may be configured for next generation vehicle-to-everything (NGV) communications in accordance with the IEEE 802.11bd standard, and one or more stations including the AP 502 may be next generation vehicle-to-everything (NGV) stations (STAs).

[0053] AP 502 may be an AP that uses IEEE 802.11 for transmission and reception. AP 502 may be a base station. AP 502 may use other communication protocols in addition to the IEEE 802.11 protocol. The IEEE 802.11 protocol may be IEEE802.11ax. The IEEE 802.11 protocol may include the use of orthogonal frequency division multiple access (orthogonal frequency division multiple-access, OFDMA), time division multiple access (time division multiple access, TDMA), and / or code division multiple access (code division multiple access, CDMA). The IEEE 802.11 protocol may include multiple access technology. 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 AP 502, which is part of an extended service set (ESS). A controller (not shown) may store information common to more than one AP 502 .

[0054] The legacy device 506 may operate in accordance with one or more of IEEE 802.11a / b / g / n / ac / ad / af / ah / aj / ay or another legacy wireless communication standard. The legacy device 506 may be a STA or an IEEE STA. The STA 504 may be a wireless transmitting and receiving device, such as a cellular phone, a portable electronic wireless communication device, a smart phone, a handheld wireless device, wireless glasses, a wireless watch, a wireless personal device, a tablet device, or another device that can transmit and receive using an IEEE 802.11 protocol (e.g., IEEE 802.11ax) or another wireless protocol. In some embodiments, the STA 504 may be referred to as a high efficiency (HE) station.

[0055] The AP 502 may communicate with the legacy device 506 in accordance with conventional IEEE 802.11 communication techniques. In an example embodiment, the AP 502 may also be configured to communicate with the STA 504 in accordance with conventional IEEE 802.11 communication techniques.

[0056] In some embodiments, a frame may be configured to have the same bandwidth as a channel. A frame may be a physical layer convergence procedure (PLCP) protocol data unit (PPDU). In some embodiments, there may be several types of PPDUs, which may have different fields and different physical layers and / or different medium access control (MAC) layers.

[0057] The bandwidth of the channel can be 20MHz, 40MHz or 80MHz, 160MHz, 320MHz continuous bandwidth or 80+80MHz (160MHz) non-continuous bandwidth. In some embodiments, the bandwidth of the channel can be 1MHz, 1.25MHz, 2.03MHz, 2.5MHz, 4.06MHz, 5MHz, and 10MHz, or a combination thereof, or another bandwidth less than or equal to the available bandwidth can also be used. In some embodiments, the bandwidth of the channel can be based on the number of active data subcarriers. In some embodiments, the bandwidth of the channel is based on 26, 52, 106, 242, 484, 996, or 2x996 active data subcarriers or tones spaced 20MHz apart. In some embodiments, the bandwidth of the channel is 256 tones spaced 20MHz apart. In some embodiments, the channel is a multiple of 26 tones or a multiple of 20MHz. In some embodiments, a 20MHz channel may include 242 active data subcarriers or tones, which may determine the size of the Fast Fourier Transform (FFT). According to some embodiments, the allocation of bandwidth or number of tones or subcarriers may be referred to as resource unit (RU) allocation.

[0058] In some embodiments, 26 subcarrier RU and 52 subcarrier RU are used in 20MHz, 40MHz, 80MHz, 160MHz, and 80+80MHz OFDMA PPDU formats. In some embodiments, 106 subcarrier RU is used in 20MHz, 40MHz, 80MHz, 160MHz, and 80+80MHz OFDMA and MU-MIMO PPDU formats. In some embodiments, 242 subcarrier RU is used in 40MHz, 80MHz, 160MHz, and 80+80MHz OFDMA and MU-MIMO PPDU formats. In some embodiments, 484 subcarrier RU is used in 80MHz, 160MHz, and 80+80MHz OFDMA and MU-MIMO PPDU formats. In some embodiments, 996 subcarrier RU is used in 160MHz and 80+80MHz OFDMA and MU-MIMO PPDU formats.

[0059] A frame may be configured to transmit several spatial streams, which may be in accordance with MU-MIMO or OFDMA. In other embodiments, the AP 502, the STA 504, and / or the legacy device 506 may also implement different technologies, such as code division multiple access (CDMA) 2000, CDMA 2000 1X, 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 Datarates for GSM Evolution (EDGE), GSM EDGE (GERAN), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), Or other techniques.

[0060] Some embodiments relate to HE and / or EHT communications. According to some IEEE 802.11 embodiments (e.g., IEEE 802.11ax embodiments), AP 502 may operate as a master station that may be arranged to compete for a wireless medium (e.g., during a contention period) to receive exclusive control of the medium during a control period. In some embodiments, the control period may be referred to as a transmission opportunity (TXOP). AP 502 may send a primary synchronization transmission at the beginning of the control period, which may be a trigger frame or a control and scheduling transmission. AP 502 may send the duration and subchannel information of the TXOP. During the control period, STA 504 may communicate with AP 502 in accordance with a non-contention-based multiple access technology (e.g., OFDMA or MU-MIMO). This is different from traditional WLAN communications, in which devices communicate in accordance with contention-based communication technologies rather than multiple access technologies. During the control period, AP 502 may communicate with station 504 using one or more frames. During the control period, STA 504 may operate on a subchannel that is smaller than the operating range of AP 502. During the control period, legacy stations refrain from communicating. Legacy stations may need to receive communications from AP 502 to defer communications.

[0061] According to some embodiments, during the TXOP, STA 504 may contend for the wireless medium, while legacy devices 506 are blocked from contending for the wireless medium during the primary synchronization transmission. In some embodiments, the trigger frame may indicate an uplink (UL) UL-MU-MIMO and / or UL OFDMA TXOP. In some embodiments, the trigger frame may include DL UL-MU-MIMO and / or DL ​​OFDMA, the schedule of which is indicated in the preamble of the trigger frame.

[0062] In some embodiments, the multiple access technology used during the TXOP may be a scheduled OFDMA technology, although this is not a requirement. In some embodiments, the multiple access technology may be a time division multiple access (TDMA) technology or a frequency division multiple access (FDMA) technology. In some embodiments, the multiple access technology may be a space division multiple access (SDMA) technology. In some embodiments, the multiple access technology may be a code division multiple access (CDMA).

[0063] The AP 502 may also communicate with legacy devices 506 and / or non-legacy stations 504 in accordance with conventional IEEE 802.11 communication techniques. In some embodiments, the AP 502 may also be configured to communicate with the STAs 504 outside of a TXOP in accordance with conventional IEEE 802.11 communication techniques, although this is not a requirement.

[0064] In some embodiments, the station 504 may be a “group owner” (GO) for peer-to-peer operation mode. The wireless device may be the station 504 or the AP 502.

[0065] In some embodiments, station 504 and / or AP 502 may be configured to operate in accordance with IEEE 802.11mc. Figure 1 The radio architecture of is configured to implement station 504 and / or AP 502. In an example embodiment, Figure 2 The front-end module circuit is configured to implement the station 504 and / or AP 502. In an example embodiment, Figure 3 The radio IC circuit is configured to implement the station 504 and / or AP 502. In an example embodiment, Figure 4 The baseband processing circuitry is configured to implement the station 504 and / or the AP 502.

[0066] In an example embodiment, the station 504, the AP 502, a device of the station 504, and / or a device of the AP 502 may include one or more of the following: Figure 1 The radio architecture of Figure 2 Front-end module circuit, Figure 3 Radio IC circuits, and / or Figure 4 Baseband processing circuit.

[0067] In an example embodiment, Figure 1 The radio architecture of Figure 2 Front-end module circuit, Figure 3 Radio IC circuits, and / or Figure 4 The baseband processing circuitry may be configured to perform the methods and operations / functions described herein.

[0068] In an example embodiment, the station 504 and / or the AP 502 are configured to perform the methods and operations / functions described herein. In an example embodiment, the apparatus of the station 504 and / or the apparatus of the AP 502 are configured to perform the methods and functions described herein. The term Wi-Fi may refer to one or more of the IEEE 802.11 communication standards. AP and STA may refer to the access point 502 and / or the station 504 and the legacy device 506.

[0069] In some embodiments, the AP and the STA may communicate in accordance with one of the IEEE 802.11 standards, including IEEE Std 802.11-2020, IEEE P802.11ax / D8.0 (October 2020), IEEE P802.11REVmd / D5.0, IEEE P802.11be / D3.0 (January 2023), and IEEE P802.11-REVme / D1.3.

[0070] Embodiments disclosed herein relate to supporting preemption of low-latency applications, particularly for next generation WLANs (including WiFi8). Figure 6 Illustrated is preemption of low latency (LL) traffic during a transmission opportunity (TXOP) in accordance with some embodiments.

[0071] Some embodiments relate to an access point station (AP) configured for ultra-high reliability (UHR) communications in a wireless local area network (WLAN). In these embodiments, when the AP is configured to receive low-latency (i.e., time-sensitive) traffic, the AP may respond to an initial frame (e.g., RTS frame 602 (see Figure 6 )) encoding for transmission. The initial frame may be encoded to indicate whether preemption for low latency (LL) traffic is enabled during a transmission opportunity (TXOP). The TXOP may have been acquired by the AP. In these embodiments, when preemption for LL traffic is enabled (i.e., permitted) during a TXOP, the AP may encode multiple downlink (DL) physical layer protocol data units (PPDUs) 606, 608, 610, etc. for transmission within the TXOP. The DL PPDUs may be sent with an extended short interframe space (xIFS) therebetween. Each DL PPDU may be encoded to indicate whether the xIFS following the DL PPDU has been enabled for preemption.

[0072] In these embodiments, when a signal including at least a legacy short training field (L-STF) is detected within one of the xIFSs enabled for preemption, the AP may suspend subsequent transmission of at least the next DL PPDU 608 and may attempt to decode a frame including the L-STF to determine whether the frame is a preemption request frame 616. In these embodiments, when it is determined that the frame is a preemption request frame 616, the AP may trigger a station (STA) to send LL traffic to the AP.

[0073] In these embodiments, the preemption request frame 616 may include a preamble that includes at least one or more training fields (e.g., L-STF and L-LTF), the one or more training fields including the L-STF followed by a signal (SIG) field. The SIG field may have a predetermined length value (e.g., length = 15) in the length field 704 (see Fig. 7A ) to indicate that the frame is a preemption request frame 616.

[0074] exist Figure 6 Examples of these embodiments are illustrated in . In these embodiments, the AP may indicate whether preemption is allowed within xIFS after SIFS after the end of the current DL PPDU. However, the AP may only be able to detect the STF and possibly the LTF of the frame during the SIFS to PIFS time before it starts sending the next DL PPDU. Therefore, when the AP detects the STF within PIFS, the AP may suspend the transmission of the next DL PPDU. If the frame is determined to be a preemption request frame, the AP may determine whether to trigger the STA to send an uplink LL packet. In these embodiments, the AP may not be able to determine whether the frame is a preemption request frame because the Tp time is around SIFS and the Tg time is PIFS. Therefore, once the AP detects the STF within the PIFS time before it sends the next scheduled PPDU, it should suspend the next PPDU transmission.

[0075] In some embodiments, the AP may be configured to suspend subsequent transmission of at least the next DL PPDU 608 when only an initial portion of the preemption request frame 616 is received within the xIFS after a predetermined time (Tp) after the start of the xIFS. The predetermined time (Tp) may be less than the xIFS (Tg). In these embodiments, the remainder of the preemption request frame 616 may be received after the end of the xIFS (i.e., after Tg).

[0076] In some embodiments, the predetermined time (Tp) may be SIFS. SIFS may be 10 microseconds, although the scope of the embodiments is not limited in this respect. In some embodiments, xIFS(Tg) may be approximately the point coordination function (PCF) interframe space (PIFS). PIFS may be 30 microseconds (long slot time for 2.5 GHz operation), 19 microseconds (short slot time for 2.5 GHz operation), and 25 microseconds (for 5 GHz operation), although the scope of the embodiments is not limited in this respect.

[0077] In some embodiments, the AP may be configured to suspend subsequent transmission of at least the next DL PPDU 608 when all parts of the preemption request frame 616 are received within xIFS after a predetermined time (Tp). In these embodiments, the preemption request frame 616 may be configured according to a short waveform design when all parts of the preemption request frame 616 are received within xIFS after a predetermined time (Tp). In these embodiments, the entire preemption request frame 616 may be received and detected within a short time range (i.e., Tg-Tp) before the start of the next DL PPDU transmission. In these embodiments, a STA with LL traffic is able to send a preemption request frame within the time Tg-Tp using a short waveform design. The shorter waveform design allows the preemption request frame to be sent within a short time (i.e., Tg-Tp), although the scope of the embodiments is not limited in this respect.

[0078] In some embodiments, the predetermined length value encoded in the SIG field is fifteen (15), although the scope of the embodiments is not limited in this respect.

[0079] In some embodiments, when no L-STF is received within xIFS after a predetermined time (Tp) and no preemption request frame 616 is received within xIFS after a predetermined time (Tp), the AP may avoid pausing subsequent transmission of the next DL PPDU 608, although the scope of the embodiments is not limited in this respect.

[0080] In some embodiments, the preemption request frame 616 may be encoded in a first frame format that includes only a preamble (the preamble includes one or more training fields and a SIG field) and may not include any additional fields including a data field or data symbols. In these embodiments, the preemption request frame 616 may not include a receiver address (RA) identifying the station sending the preemption request frame 616. In some of these embodiments, the preemption request frame may include only a PHY preamble. Fig. 7A and Figure 7B An example of this first frame format is shown in It should be noted that in these embodiments, the AP cannot identify the specific station that sent the preemption request frame.

[0081] In some embodiments, the AP may be configured to determine that a frame is a preemption request frame 616 when the SIG field has a predetermined length value in the length field 704 and the SIG field has a predetermined rate value in the rate field 702 indicating a highest supported data rate (e.g., MCS=7). Fig. 7A An example of this is shown in .

[0082] In some of these embodiments, the predetermined length value is fifteen (15) and the predetermined rate value is MCS=7, indicating the highest supported data rate, although the scope of the embodiments is not limited in this respect. In some of these embodiments, the preamble may include a known signal comprising a conventional IEEE 802.11a preamble without data symbols, wherein the length field and the MCS field are set to predefined values ​​not used in IEEE 802.11a. In these embodiments, the value of the length field may be predetermined or defined. For example, the length field may be set to 0 or a value between 0 and 15. The value of the rate field (i.e., MCS) may also be predetermined or defined. For example, the MCS may be selected between 0 and 7. Therefore, conventional devices will not be able to pass a frame check sequence (FCS).

[0083] In some alternative embodiments, the preemption request frame 616 may also include a data portion following the preamble. In these alternative embodiments, the data portion may be configured in accordance with a short feedback medium access control (MAC) frame format that includes a frame control field 705, a receiver address (RA) field 706, and a feedback type field 708. In these embodiments, the frame control field 705 may include a type value, a subtype value, and a control frame extension value. In these embodiments, the AP may determine that the frame is a preemption request frame 616 based on a combination of the type value, the subtype value, and the control frame extension value, and the value of the feedback type field 708, although the scope of the embodiments is not limited in this respect. Figure 7C An example of a short feedback MAC frame format is illustrated in Fig.7D An example of the frame control and feedback type fields is illustrated in FIG.

[0084] In some embodiments, the DL PPDU is sent to the first station (STA1). In these embodiments, the preemption request frame 616 may be received from the first station (STA1) or the second station (STA2). In these embodiments, when the AP suspends transmission of the next DL PPDU 608, the AP may decode the LL transmission received from the first station or the second station within the TXOP. In these embodiments, the LL transmission may include LL traffic.

[0085] In these embodiments, the station receiving the DL PPDU (i.e., STA1) may send a preemption request frame 616, or another station (i.e., STA2) may send a preemption request frame 616. When the preemption request frame 616 is received from the first station, it is the first station that preempts the DL PPDU transmission to itself. When the preemption request frame 616 is received from another station (i.e., STA2), it is the other station that preempts the DL PPDU transmission to the first station.

[0086] In some embodiments, to trigger the STA to send LL traffic when the frame is determined to be a preemption request frame 616 and the AP suspends the transmission of the next DL PPDU 608, the AP may encode a null-data packet (NDP) feedback report (NFR) for transmission to trigger one or more LLSTAs to report buffer stations, although the scope of the embodiments is not limited in this respect. In these embodiments, the AP may decode LL traffic received from one or more LL STAs on previously allocated resources during the TXOP.

[0087] In some embodiments, when a frame is determined to be a preemption request frame 616 and the AP suspends transmission of the next DL PPDU 608, the AP may trigger one or more LL STAs to send LL traffic during the TXOP according to a random access technique based on uplink orthogonal frequency division multiple access (UL OFDMA), although the scope of the embodiments is not limited in this respect.

[0088] In some other embodiments, when the frame is determined to be a preemption request frame 616, the AP may suspend transmission of the next DL PPDU 608 for reception of LL traffic and terminate the TXOP to release the channel, thereby allowing one or more LL STAs to transmit LL traffic in accordance with enhanced distributed channel access (EDCA) technology, although the scope of the embodiments is not limited in this respect.

[0089] In some embodiments, when the initial frame is encoded to indicate that preemption for LL traffic is not enabled during the TXOP, the AP may encode an aggregated MPDU (A-MPDU) for transmission during the TXOP. In these embodiments, the A-MPDU may include multiple DL PPDUs. In these embodiments, when LL traffic is not enabled during the TXOP, no xIFS is available because the A-MPDU may be sent instead of multiple DL PPDUs. On the other hand, when the AP wishes to enable preemption for LL traffic during the TXOP, downlink traffic that would have been sent in an A-MPDU may be sent in multiple DL PPDUs to allow xIFS to be included between the DL PPDUs.

[0090] In some embodiments, the AP may be configured to avoid triggering a station (STA) to send LL traffic when a frame is determined to be a control frame other than the preemption request frame 616 .

[0091] Some embodiments relate to a non-transitory computer-readable storage medium storing instructions for execution by a processing circuit of an access point station (AP) configured for ultra-high reliability (UHR) communications in a wireless local area network (WLAN). In these embodiments, when the AP may be configured to receive low-latency (i.e., time-sensitive) traffic and may be used for an initial frame for transmission (e.g., RTS frame 602 (see Figure 6 )) encoding, the initial frame may be encoded to indicate whether preemption of low latency (LL) traffic is enabled during a transmission opportunity (TXOP). The TXOP may have been acquired by the AP. In these embodiments, when preemption of LL traffic is enabled (i.e., permitted) during a TXOP, the AP may encode multiple downlink (DL) physical layer protocol data units (PPDUs) 606, 608, 610, etc. for transmission within the TXOP. The DL PPDUs may be sent with an extended short interframe space (xIFS) therebetween. Each DL PPDU may be encoded to indicate whether the xIFS following the DL PPDU has been enabled for preemption.

[0092] Some embodiments relate to a non-access point station (STA) configured for ultra-high reliability (UHR) communications in a wireless local area network (WLAN). In these embodiments, when the STA is configured to send low-latency (i.e., time-sensitive) traffic, the STA may respond to an initial frame (e.g., RTS frame 602 (see FIG. 1 ) received from an access point (AP) Figure 6)) decoding. The initial frame may indicate whether preemption for low latency (LL) traffic is enabled during a transmission opportunity (TXOP) acquired by the AP. In these embodiments, when preemption for LL traffic is enabled during a TXOP, the STA may decode at least an initial portion of one or more of a plurality of downlink (DL) physical layer protocol data units (PPDUs) 606, 608, 610, etc. sent by the AP within the TXOP to determine whether preemption is enabled within an extended short interframe space (xIFS) following one of the DL PPDUs. When the STA has LL traffic available for transmission, the STA may encode a preemption request frame for transmission to the AP during one of the xIFSs indicated as enabled for preemption. In these embodiments, the STA may receive a trigger from the AP to trigger transmission of LL traffic in the TXOP. In these embodiments, the STA may send at least a legacy short training field (L-STF) of a preemption request frame within the xIFS after a predetermined time (Tp) after the start of the xIFS. As Figure 6 As shown in , the predetermined time (Tp) is less than xIFS (Tg).

[0093] In some embodiments, the STA may encode the preemption request frame 616 to include a preamble including at least one or more training fields (e.g., L-STF and L-LTF), including an L-STF followed by a signal (SIG) field. The SIG field may have a predetermined length value (e.g., length = 15) in the length field 704 (see Fig. 7A ) to indicate that the frame is a preemption request frame 616.

[0094] In these embodiments, a large PPDU may be divided into small PPDUs with maximum length limits and time gaps to enable preemption opportunities for LL transmitters. In these embodiments, one or more LL stations (STAs) (i.e., LL transmitters) may begin sending a common preemption request (PR) during the time gap to indicate that it has LL packets to send when preemption is allowed. This may help avoid collisions between multiple LL transmitters and may help avoid periodically reserving time slots for LL traffic within a TXOP. The PR may be re-tapped before the next PPDU. g PR frame is sent within.

[0095] In these embodiments, in order to determine the priority of the LL transmitter, the LL transmitter (T P ) is used with TXOP holders (T g )T used to send data / TF / BA g Compared with the shorter xIFS(T P ) channel access to send public PR, such as Figure 6 Note: T P <Tg In these embodiments, the PR frame can only be sent before the next PPDU from the AP to avoid the hidden node problem between STAs, which means that the STA cannot directly preempt the STA. After receiving the public PR, the AP can use the following different methods to support LL packet transmission.

[0096] In some embodiments, the AP may use NFRP to trigger the LL STA to feedback the LL buffer status and then trigger LL data transmission. The trigger for the feedback of the LL STA may be implicit, so that the LL STA may send feedback directly (e.g., via NFR or OFDMA random access) without a common PR and feedback trigger, or may send feedback with a common PR (e.g., via NFR) but without a feedback trigger. In these cases, the AP may allocate frequency resources (e.g., a subcarrier set) to the LL STA in advance.

[0097] In some embodiments, the AP may trigger the LL STA to send LL packets using uplink OFDMA-based random access. The triggering of the uplink of the LL STA may be implicit, so that the LL STA may directly send the uplink without a common PR and an uplink trigger; or send an uplink with a common PR but without an uplink trigger. In these embodiments, the AP may allocate frequency resources (e.g., OFDMA RUs) to the LL STA in advance.

[0098] In some other embodiments, the AP may terminate the TXOP early and release the channel for LL transmission with EDCA, although the scope of the embodiments is not limited in this respect.

[0099] Fig. 7A A preemption request control frame is illustrated in accordance with some embodiments. Figure 7B A preemption request control frame according to some other embodiments is illustrated. In some of these embodiments, the preemption request control frame can be indicated by a combination of the rate and length fields in the PHY preamble. An example is to use the highest supported data rate MCS 7 and unused length field value 15. In these embodiments, the PSDU will be packaged with the dump packet. For a traditional mode user, after receiving this preemption request frame, it will treat it as an erroneous PSDU after the FCS check error. For a new device that is the current TXOP holder and is able to decode this new preemption request control frame, it will suspend subsequent PPDU transmissions.

[0100] Figure 7CThe short feedback MAC frame format of a preemption request frame according to some embodiments is illustrated. In these embodiments, the length field in the preamble is equal to 15. The short feedback MAC frame consists of frame control (2 bytes), duration / ID (2 bytes), RA (6 bytes), feedback type (2 bytes), and FCS (4 bytes). As shown in the table above, the preemption request control frame will be indicated by a combination of the type, subtype, control frame extension, and feedback type fields. Note that this short new feedback MAC frame format can be extended by using the remaining feedback type field values ​​(0001-1111) to support other functions, such as MCS adjustment or SNR feedback for link adaptation. Fig.7D Illustrated is a frame control and feedback time field according to some embodiments.

[0101] In some embodiments, since the AP only allows LL STAs to P PR is sent within T (i.e., before all other devices), so the AP can assume that P The PPDU received in the AP is from the designated LL STA. Therefore, the PSDU may not be required. In other words, the signal known to the AP can work. For example, Fig. 7A and Figure 7B As shown, the known signal may be a legacy 802.11a preamble without data symbols. The value setting of the length field may be defined in the specification. For example, the length field may be set to 0 or a value between 0 and 15. The value setting of the MCS may also be defined in the specification. For example, the MCS may be selected between 0 and 7. Legacy devices will not be able to pass the FCS.

[0102] In some embodiments, an unavailable length value of 15 may be used to indicate a preemption request frame. Similarly, MCS settings not used by 802.11a may also be used to indicate a preemption request frame. For example, 0000, 0010, and the other six values ​​are not used by 802.11a and may be used to indicate a preemption request frame.

[0103] Figure 8 A functional block diagram of a wireless communication device according to some embodiments is illustrated. In one embodiment, Figure 8 The functional block diagram of a communication station (STA) that can be suitable for use as an AP STA, a non-AP STA, or other user equipment according to some embodiments is illustrated. The wireless communication device 800 can also be suitable for use as a handheld device, a mobile device, a cellular phone, a smart phone, a tablet device, a netbook, a wireless terminal, a laptop computer, a wearable computer device, a femtocell, a high data rate (HDR) subscriber device, an access point, an access terminal, or other personal communication system (PCS) equipment.

[0104] The wireless communication device 800 may include a communication circuit 802 and a transceiver 810 for sending and receiving signals to and from other communication devices using one or more antennas 801. The communication circuit 802 may include such circuits: such circuits are operable to control physical layer (PHY) communications and / or medium access control (MAC) communications for access to a wireless medium, and / or any other communication layer for sending and receiving signals. The wireless communication device 800 may also include a processing circuit 806 and a memory 808 arranged to perform the operations described herein. In some embodiments, the communication circuit 802 and the processing circuit 806 may be configured to perform the operations detailed in the above-mentioned figures, schematic diagrams, and processes.

[0105] According to some embodiments, the communication circuit 802 may be arranged to contend for a wireless medium and configure a frame or packet to communicate over the wireless medium. The communication circuit 802 may be arranged to send and receive signals. The communication circuit 802 may also include circuits for modulation / demodulation, up-conversion / down-conversion, filtering, amplification, and the like. In some embodiments, the processing circuit 806 of the wireless communication device 800 may include one or more processors. In other embodiments, two or more antennas 801 may be coupled to the communication circuit 802 arranged to send and receive signals. The memory 808 may store information for configuring the processing circuit 806 to perform operations for configuring and sending message frames and performing various operations described herein. The memory 808 may include any type of memory for storing information in a machine (e.g., computer) readable form, including non-transitory memory. For example, the memory 808 may include a computer-readable storage device, a read-only memory (ROM), a random-access memory (RAM), a disk storage medium, an optical storage medium, a flash memory device, and other storage devices and media.

[0106] In some embodiments, the wireless communication device 800 can be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capabilities, a web tablet, a wireless telephone, a smart phone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), a wearable computer device, or another device that can wirelessly receive and / or send information.

[0107] In some embodiments, the wireless communication device 800 may include one or more antennas 801. Antenna 801 may include one or more directional or omnidirectional antennas, such as dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for the transmission of RF signals. In some embodiments, instead of two or more antennas, a single antenna with multiple apertures may be used. In these embodiments, each aperture may be considered as a separate antenna. In some multiple-input multiple-output (MIMO) embodiments, antennas may be effectively separated to obtain spatial diversity and may generate different channel characteristics between each antenna and the antenna of the transmitting device.

[0108] In some embodiments, the wireless communication device 800 may include one or more of the following: a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, a speaker, and other mobile device elements. The display may be an LCD screen including a touch screen.

[0109] Although the wireless communication device 800 is illustrated as having several separate functional elements, two or more of these functional elements may be combined and may be implemented by a combination of software-configured elements (e.g., processing elements including a digital signal processor (DSP)) and / or other hardware elements. For example, some elements may include 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 circuits for performing at least the functions described herein. In some embodiments, the functional elements of the wireless communication device 800 may refer to one or more processes operating on one or more processing elements.

[0110] Fig. 9 is a process 900 of receiving low latency (LL) traffic by an access point station (AP) configured for ultra high reliability (UHR) communications in a wireless local area network (WLAN) in accordance with some embodiments.

[0111] The AP may encode an initial frame for transmission in operation 902. The initial frame may be encoded to indicate whether preemption for low latency (LL) traffic is enabled during the TXOP.

[0112] In operation 904, the AP may encode multiple downlink (DL) physical layer protocol data units (PPDUs) for transmission within the TXOP. The DL PPDUs may be sent with an extended short interframe space (xIFS) therebetween. Each DL PPDU may be encoded to indicate whether the following xIFS has been enabled for preemption.

[0113] In operation 906, when a signal including at least a legacy short training field (L-STF) is detected within one of the xIFSs enabled for preemption, the AP may suspend subsequent transmission of a next DL PPDU.

[0114] In operation 908, the AP may attempt to decode the frame including the L-STF to determine whether the frame is a preemption request frame.

[0115] In operation 910, when determining that the frame is a preemption request frame, the AP may trigger a station (STA) to transmit LL traffic.

[0116] The Abstract is provided to comply with 37 CFR Section 1.72(b), which requires an abstract that will allow the reader to ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to limit or interpret the scope or meaning of the claims. The appended claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims

1. An apparatus of an access point station (AP) configured for ultra-high reliability (UHR) communications in a wireless local area network (WLAN), the apparatus comprising a processing circuit and a memory, wherein: The processing circuit is configured to: encoding an initial frame for transmission, the initial frame being encoded to indicate whether preemption for low latency (LL) traffic is enabled during a transmission opportunity (TXOP); Wherein, when preemption of LL traffic is enabled during the TXOP, the processing circuit is configured to: encoding a plurality of downlink (DL) physical layer protocol data units (PPDUs) for transmission within the TXOP, the DL PPDUs being transmitted with an extended short interframe space (xIFS) therebetween, each of the DL PPDUs being encoded to indicate whether a subsequent xIFS is enabled for preemption; and When a signal including at least a legacy short training field (L-STF) is detected within one of the xIFSs enabled for preemption, the processing circuit is configured to: suspending subsequent transmission of a next DL PPDU in the DL PPDU; attempting to decode a frame including the L-STF to determine whether the frame is a preemption request frame; and When it is determined that the frame is a preemption request frame, the station (STA) is triggered to send LL traffic, The preemption request frame includes a preamble, which includes at least one or more training fields, and the one or more training fields include the L-STF followed by a signal (SIG) field, and the SIG field has a predetermined length value in the length field to indicate that the frame is a preemption request frame.

2. The device according to claim 1, wherein: The processing circuit is configured to: when the initial part of the preemption request frame is received within the xIFS after a predetermined time (Tp) after the start of the xIFS, suspend subsequent transmission of the next DLPPDU, the predetermined time (Tp) being less than the xIFS, and The remaining part of the preemption request frame is received after the xIFS ends.

3. The device as claimed in claim 2, wherein: The processing circuit is configured to: when all parts of the preemption request frame are received within the xIFS after the predetermined time (Tp), suspend subsequent transmission of the next DL PPDU, Wherein, when all parts of the preemption request frame are received within the xIFS after the predetermined time (Tp), the preemption request frame is configured according to a short waveform design.

4. The device as claimed in claim 3, wherein: The predetermined length value encoded in the SIG field is fifteen (15).

5. The device according to claim 4, wherein: When no L-STF is received within the xIFS after the predetermined time (Tp), and no preemption request frame is received within the xIFS after the predetermined time (Tp), the processing circuit is configured to avoid pausing subsequent transmission of the next DL PPDU.

6. The device according to claim 5, wherein: The preemption request frame is encoded according to a first frame format, the first frame format includes the preamble and does not include a data field, the preamble includes the one or more training fields and the SIG field, and the preemption request frame does not include a receiver address identifying a station receiving the preemption request frame.

7. The device according to claim 6, wherein: The processing circuit is configured to determine that the frame is a preemption request frame when the SIG field has the predetermined length value in the length field and the SIG field has a predetermined rate value in the rate field.

8. The device according to claim 5, wherein: The preemption request frame further includes a data portion after the preamble, the data portion being configured in accordance with a short feedback medium access control (MAC) frame format, the short feedback MAC frame format including a frame control field, a receiver address (RA) field, and a feedback type field, the frame control field including a type value, a subtype value, and a control frame extension value, and The processing circuit is configured to determine whether the frame is a preemption request frame based on a combination of the type value, the subtype value, and the control frame extension value and a value of the feedback type field.

9. The device according to claim 5, wherein: The DL PPDU is transmitted to a first station (STA1), and wherein the preemption request frame is received from one of the first station (STA1) and a second station (STA2), and Wherein, when the processing circuit suspends transmission of the next DL PPDU, the processing circuit is configured to decode a LL transmission received from one of the first station and the second station within the TXOP, the LL transmission including the LL traffic.

10. The device according to claim 5, wherein: In order to trigger the STA to send the LL traffic when it is determined that the frame is a preemption request frame and the processing circuit suspends the transmission of the next DL PPDU, the processing circuit is configured to: Encode a Null Data Packet (NDP) Feedback Report (NFR) for transmission to trigger one or more LL STAs to report buffer stations; and The LL traffic received from the one or more LL STAs on the allocated resources during the TXOP is decoded.

11. The device according to claim 5, wherein: When it is determined that the frame is a preemption request frame and the processing circuit suspends transmission of the next DL PPDU, the processing circuit is configured to: trigger one or more LL STAs to send the LL traffic during the TXOP according to a random access technique based on uplink orthogonal frequency division multiple access (UL OFDMA).

12. The device of claim 5, wherein: In order to receive the LL traffic when it is determined that the frame is a preemption request frame, the processing circuit is configured to: suspend transmission of the next DL PPDU and terminate the TXOP to release the TXOP to allow one or more LL STAs to transmit the LL traffic according to the enhanced distributed channel access (EDCA) technology.

13. The device of claim 5, wherein: When the initial frame is encoded to indicate that preemption for LL traffic is not enabled during the TXOP, the processing circuit is configured to encode an aggregated MPDU (A-MPDU) for transmission during the TXOP, the A-MPDU including the plurality of DL PPDUs.

14. The device of claim 1, wherein: The processing circuit is configured to avoid triggering the station (STA) to send LL traffic when determining that the frame is a control frame that is not a preemption request frame.

15. A computer-readable storage medium storing instructions for execution by a processing circuit of an access point station (AP) configured for ultra-high reliability (UHR) communications in a wireless local area network (WLAN), wherein: The processing circuit is configured to: encoding an initial frame for transmission, the initial frame being encoded to indicate whether preemption for low latency (LL) traffic is enabled during a transmission opportunity (TXOP); Wherein, when preemption of LL traffic is enabled during the TXOP, the processing circuit is configured to: encoding a plurality of downlink (DL) physical layer protocol data units (PPDUs) for transmission within the TXOP, the DL PPDUs being transmitted with an extended short interframe space (xIFS) therebetween, each of the DL PPDUs being encoded to indicate whether a subsequent xIFS is enabled for preemption; and When a signal including at least a legacy short training field (L-STF) is detected within one of the xIFSs enabled for preemption, the processing circuit is configured to: suspending subsequent transmission of a next DL PPDU in the DL PPDU; attempting to decode a frame including the L-STF to determine whether the frame is a preemption request frame; and When it is determined that the frame is a preemption request frame, the station (STA) is triggered to send LL traffic, The preemption request frame includes a preamble, which includes at least one or more training fields, and the one or more training fields include the L-STF followed by a signal (SIG) field, and the SIG field has a predetermined length value in the length field to indicate that the frame is a preemption request frame.

16. The computer-readable storage medium of claim 15, wherein: The processing circuit is configured to: when an initial portion of the preemption request frame is received within the xIFS after a predetermined time (Tp) after the start of the xIFS, suspend subsequent transmission of the next DL PPDU, the predetermined time (Tp) being less than the xIFS, and The remaining part of the preemption request frame is received after the xIFS ends.

17. The computer-readable storage medium of claim 16, wherein: The processing circuit is configured to: when all parts of the preemption request frame are received within the xIFS after the predetermined time (Tp), suspend subsequent transmission of the next DL PPDU, Wherein, when all parts of the preemption request frame are received within the xIFS after the predetermined time (Tp), the preemption request frame is configured according to a short waveform design.

18. The computer-readable storage medium of claim 17, wherein: The predetermined length value encoded in the SIG field is fifteen (15), and Wherein, when no L-STF is received within the xIFS after the predetermined time (Tp), and no preemption request frame is received within the xIFS after the predetermined time (Tp), the processing circuit is configured to avoid pausing subsequent transmission of the next DL PPDU.

19. An apparatus of a non-access point station (STA) configured for ultra-high reliability (UHR) communications in a wireless local area network (WLAN), the apparatus comprising processing circuitry and memory, wherein: The processing circuit is configured to: decoding an initialization frame received from an access point (AP), the initialization frame indicating whether preemption for low latency (LL) traffic is enabled during a transmission opportunity (TXOP) acquired by the AP; Wherein, when preemption of LL traffic is enabled during the TXOP, the processing circuit is configured to: decoding at least an initial portion of one or more downlink (DL) physical layer protocol data units (PPDUs) among a plurality of DL PPDUs sent by the AP within the TXOP to determine whether preemption is enabled within an extended short interframe space (xIFS) following one of the DL PPDUs; When the STA has LL traffic available for transmission, the processing circuit is configured to: encoding a preemption request frame for transmission to the AP during one of the xIFSs indicated as enabled for preemption; and receiving a trigger from the AP to trigger transmission of the LL traffic in the TXOP, The processing circuit is configured to enable the STA to send at least the legacy short training field (L-STF) of the preemption request frame within the xIFS after a predetermined time (Tp) after the start of the xIFS, and the predetermined time (Tp) is less than the xIFS.

20. The device of claim 19, wherein: The processing circuit is configured to encode the preemption request frame to include a preamble, which includes at least one or more training fields, the one or more training fields including the L-STF followed by a signal (SIG) field, and the SIG field has a predetermined length value in a length field to indicate that the frame is a preemption request frame.

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