Trigger frame for dynamic subband operation

Abstract

Embodiments include generating, by an access point (AP), a trigger frame requesting a response from one or more stations (STAs) and including information for a dynamic sub-band switching operation, wherein the trigger frame includes a common information field providing information common to the one or more STAs and one or more user information fields each providing information specific to a particular STA of the one or more STAs; transmitting the trigger frame to the one or more STAs to request the dynamic sub-band switching operation; and determining whether the dynamic sub-band switching operation is successfully performed at the one or more STAs based on whether a response responsive to the trigger frame is received from the one or more STAs.

Description

Technical Field

[0001] This disclosure generally relates to wireless communication systems, and more specifically, to trigger frames for, but not limited to, dynamic subband operation. Background Technology

[0002] Since the late 1990s, Wireless Local Area Network (WLAN) technology has evolved towards increasing data rates and continues to grow in various markets such as homes, businesses, and hotspots. WLAN allows devices to access the Internet in the 2.4 GHz, 5 GHz, 6 GHz, or 60 GHz frequency bands. WLAN is based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. The IEEE 802.11 standard family aims to improve speed and reliability and extend the operational range of wireless networks.

[0003] WLAN devices increasingly need to support a variety of latency-sensitive or real-time applications, such as augmented reality (AR), robotics, artificial intelligence (AI), cloud computing, and autonomous vehicles. To achieve the extremely low latency and extremely high throughput required for such applications, Multi-Link Operation (MLO) has been proposed for WLANs. A WLAN is formed by WLAN devices within a limited area such as a home, school, apartment, or office building. Each WLAN device can have one or more Stations (STAs), such as Access Point (AP) STAs and Non-Access Point (Non-AP) STAs.

[0004] MLO enables non-AP multi-link devices (MLDs) to establish multiple links with AP MLDs. Each of these links can independently enable channel access and frame switching between the non-AP MLD and the AP MLD, which can reduce latency and increase throughput.

[0005] The descriptions set forth in the Background section should not be assumed to be prior art simply because they are set forth in the Background section. The Background section may describe aspects or embodiments of this disclosure. Summary of the Invention

[0006] Solution to the problem

[0007] One aspect of this disclosure provides an access point (AP) in a wireless network, including: a memory; and a processor coupled to the memory. The processor is configured to generate a trigger frame that requests a response from one or more stations (STAs) and includes information for a dynamic subband handover operation, wherein the trigger frame includes a common information field and one or more user information fields, the common information field providing information shared by the one or more STAs, and each user information field providing information specific to a particular STA among the one or more STAs. The processor is configured to send the trigger frame to the one or more STAs to request the dynamic subband handover operation. The processor is configured to determine whether the dynamic subband handover operation was successfully performed at the one or more STAs based on whether a response to the trigger frame was received from the one or more STAs.

[0008] In some embodiments, the public information field includes a trigger frame that triggers a dynamic subband switching operation for at least one or more STAs, and one or more user information fields include an indication of information associated with the dynamic subband switching operation.

[0009] In some embodiments, one or more user information fields are addressed to the Dynamic Subband Operation (STA) and include information associated with the Dynamic Subband Switching Operation.

[0010] In some embodiments, the trigger frame is a multi-user request transport (MU-RTS).

[0011] In some embodiments, the processor is further configured to: determine that no frame in response to the trigger frame has been received on the main channel; and determine that the triggering operation has failed at one or more STAs.

[0012] In some embodiments, the processor is also configured to receive a frame in response to a trigger frame from at least one of one or more STAs on any subchannel of a transmission opportunity (TXOP); determine that a subband switching operation was successful at at least one of one or more STAs; and initiate a transmission to at least one of one or more STAs while also signaling to occupy the medium on the main channel.

[0013] In some embodiments, the trigger frame includes a field that includes information used by one or more STAs to determine the transmit power in order to transmit a response.

[0014] In some embodiments, the effect of the residual carrier frequency offset between the trigger frame and the expected response of a particular dynamic subband operation STA is mitigated by one or more of the following: limiting the transmission parameters of the response frame, including modulation and coding schemes or response transmission duration; and including a field in the trigger frame that includes information used by the particular dynamic subband operation STA to determine the residual carrier frequency offset after performing a channel switch to the indicated subband.

[0015] In some embodiments, the resource allocation to one or more dynamic subband STAs indicated in the trigger frame comes from a set of subbands negotiated between the AP and one or more dynamic subband STAs.

[0016] In some embodiments, the trigger frame indicates whether one or more STAs need to perform energy detection or preamble detection on a new subchannel within a certain amount of time after the end of the trigger frame before transmitting a response.

[0017] One aspect of this disclosure provides a station (STA) in a wireless network, including: a memory; and a processor coupled to the memory. The processor is configured to receive from an access point (AP) a trigger frame requesting a dynamic subband handover operation, wherein the trigger frame includes a common information field and one or more user information fields, the common information field providing information common to one or more STAs, and each user information field providing information specific to a particular STA among the one or more STAs. The processor is configured to perform the dynamic subband handover operation requested in the trigger frame. The processor is configured to send a transmission permission response frame to the AP in response to the trigger frame.

[0018] In some embodiments, the public information field includes a trigger frame that triggers a dynamic subband switching operation for at least one or more STAs, and one or more user information fields include an indication of information associated with the dynamic subband switching operation.

[0019] In some embodiments, the triggering frame is a Multi-User Request Transmit (MU-RTS) frame, a Block Acknowledgment Request (BAR) frame, or a Buffer Status Report Polling (BSRP) frame.

[0020] One aspect of this disclosure provides a computer-implemented method for wireless communication at an access point (AP) in a wireless network. The method includes generating a trigger frame that requests a response from one or more stations (STAs) and includes information for dynamic subband handover operations. The trigger frame includes a common information field and one or more user information fields, the common information field providing information shared by the one or more STAs, and each user information field providing information specific to a particular STA among the one or more STAs. The method includes sending the trigger frame to the one or more STAs to request dynamic subband handover operations. The method includes determining whether the dynamic subband handover operation was successfully performed at the one or more STAs based on whether a response to the trigger frame was received from the one or more STAs.

[0021] In some embodiments, the public information field includes a trigger frame that triggers a dynamic subband switching operation for at least one or more STAs, and one or more user information fields include an indication of information associated with the dynamic subband switching operation.

[0022] In some embodiments, one or more user information fields are addressed to the Dynamic Subband Operation (STA) and include information associated with the Dynamic Subband Switching Operation.

[0023] In some embodiments, the triggering frame is a Multi-User Request Transmit (MU-RTS) frame, a Block Acknowledgment Request (BAR) frame, or a Buffer Status Report Polling (BSRP) frame.

[0024] In some embodiments, the method further includes: determining that no frame in response to the trigger frame has been received on the main channel; and determining that the triggering operation has failed at one or more STAs.

[0025] In some embodiments, the method further includes: receiving a frame in response to a trigger frame from at least one of one or more STAs on any subchannel of a transmission opportunity (TXOP); determining that a subband switching operation was successful at at least one of one or more STAs; and initiating a transmission to at least one of one or more STAs while also signaling to occupy the medium on the main channel.

[0026] In some embodiments, the trigger frame includes a field that includes information used by one or more STAs to determine the transmit power in order to transmit a response. Attached Figure Description

[0027] Figure 1 An example of a wireless network according to an embodiment is shown.

[0028] Figure 2a An example of an AP according to an embodiment is shown.

[0029] Figure 2b An example of a STA according to an embodiment is shown.

[0030] Figure 3 An example of multi-link communication operation according to an embodiment is shown.

[0031] Figure 4 The Extremely High Throughput (EHT) operating element transmitted by the AP according to an embodiment is shown.

[0032] Figure 5 The Very High Throughput (VHT) capability elements according to an embodiment are shown.

[0033] Figure 6 The Multi-User Request Transmission (MU-RTS) trigger frame format according to an embodiment is shown.

[0034] Figure 7 The buffer status report polling (BSRP) trigger frame format according to an embodiment is shown.

[0035] Figure 8 An example of wasted Basic Service Set (BSS) bandwidth according to an embodiment is shown.

[0036] Figure 9 The Dynamic Subband Operation (DSO) switching operation according to an embodiment is illustrated.

[0037] Figure 10a The operation process of an enhanced multi-link single radio operation (EMLSR) link according to an embodiment is illustrated.

[0038] Figure 10b The operation of a non-AP MLD in an enhanced multi-link multi-radio (EMLMR) mode according to an embodiment is illustrated.

[0039] Figure 11 Examples of serving a DSO device on a secondary channel and serving a non-DSO STA on a primary channel are shown according to embodiments.

[0040] Figure 12a The common information field of the MU-RTS frame as the initial control (IC) for subband switching (SBS) according to an embodiment is shown.

[0041] Figure 12b An example of the common information field of the MU-RTS frame as an SBS IC according to an embodiment is shown.

[0042] Figure 13 The user information field of the MU-RTS frame as an SBS IC according to an embodiment is shown.

[0043] Figure 14aThe Pre-Frame Check Sequence (Pre-FCS) field at the end of the user information list of the MU-RTS frame according to an embodiment is shown.

[0044] Figure 14b The Pre-FCS field at the end of the user information list, which includes the Pre-FCS identifier subfield, is shown according to an embodiment.

[0045] Figure 14c The Pre-FCS field, which is part of two special user information fields in the MU-RTS frame according to an embodiment, is shown.

[0046] Figure 14d The Pre-FCS field is shown in the second of the two special user information fields in the MU-RTS frame according to an embodiment.

[0047] Figure 14e The short Pre-FCS field in a special user information field of a MU-RTS frame according to an embodiment is shown.

[0048] Figure 14f A special sequence indicating the termination of the Pre-FCS field of the STA is shown according to an embodiment.

[0049] Figure 15 The hidden node problem of Dynamic Subband Operation (DSO) operation according to an embodiment is illustrated.

[0050] Figure 16 A Physical Protocol Data Unit (PPDU) carrying an SBS IC frame is shown according to an embodiment.

[0051] Figure 17a An example is shown of whether a DSO device according to an embodiment can receive BSRP as an indication of SBSIC in a UHR capability element.

[0052] Figure 17b An example is shown of whether a DSO device according to an embodiment can receive a BSRP as an indication of an SBS IC in a DSO notification frame.

[0053] Figure 18 The EML control field, as an optional subfield of the DSO notification frame according to an embodiment, is shown.

[0054] Figure 19 A flowchart is shown illustrating an example process performed by the AP to send an SBS IC frame to initiate a subband switching operation for the DSO device.

[0055] Figure 20A flowchart illustrating an example process for transmitting a corresponding response, performed by a non-AP STA upon receiving an SBS IC frame, according to an embodiment, is shown.

[0056] Figure 21 The user information field of the SBS IC according to an embodiment is shown.

[0057] Figure 22 The user information field of SBS according to an embodiment is shown.

[0058] In one or more embodiments, not all components depicted in each figure are necessary, and one or more embodiments may include additional components not shown in the figures. Variations in the arrangement and type of components may be made without departing from the scope of this subject matter disclosure. Additional components, different components, or fewer components may be utilized within the scope of this subject matter disclosure. Detailed Implementation

[0059] The detailed description set forth below in conjunction with the accompanying drawings is intended to describe various embodiments and is not intended to represent the only embodiments in which the subject matter can be practiced. Rather, this detailed description includes specific details to provide a thorough understanding of the subject matter of the invention. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the scope of this disclosure. Therefore, the drawings and description are to be considered illustrative rather than restrictive in nature. The same reference numerals denote the same elements.

[0060] The following description pertains to certain implementations for the purpose of describing the innovative aspects of this disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in a variety of different ways. The examples in this disclosure are based on WLAN communication in accordance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, including the IEEE 802.11be standard and any future revisions to the IEEE 802.11 standard. However, the described embodiments can be implemented in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals according to the IEEE 802.11 standard, Bluetooth standard, Global System for Mobile Communications (GSM), GSM / General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunking Radio (TETRA), Wideband CDMA (W-CDMA), Evolved Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High-Speed ​​Packet Access (HSPA), High-Speed ​​Downlink Packet Access (HSDPA), High-Speed ​​Uplink Packet Access (HSUPA), Evolved High-Speed ​​Packet Access (HSPA+), Long Term Evolution (LTE), 5G NR (New Radio), AMPS, or other known signals for communicating within wireless, cellular, or Internet of Things (IoT) networks, such as systems utilizing 3G, 4G, 5G, 6G, or further implementations thereof.

[0061] Depending on the network type, other well-known terms may be used instead of "access point" or "AP," such as "router" or "gateway." For convenience, the term "AP" is used in this disclosure to refer to a network infrastructure component that provides wireless access to remote terminals. In a WLAN, assuming that the AP also contends for the wireless channel, the AP may also be referred to as a STA. Furthermore, depending on the network type, other well-known terms may be used instead of "station" or "STA," such as "mobile station," "subscriber station," "remote terminal," "user equipment," "wireless terminal," or "user device." For convenience, the terms "station" and "STA" are used in this disclosure to refer to a remote wireless device that wirelessly accesses an AP or contends for a wireless channel in a WLAN, whether the STA is a mobile device (such as a mobile phone or smartphone) or is generally considered a fixed device (such as a desktop computer, AP, media player, fixed sensor, television, etc.).

[0062] Multilink Operation (MLO) is a key feature that standards bodies are currently developing for next-generation Ultra High Throughput (EHT) Wi-Fi systems in IEEE 802.11be. Wi-Fi devices that support MLO are called Multilink Devices (MLDs). Using MLO, a non-AP MLD can discover, authenticate, associate, and establish multiple links with an AP MLD. Channel access and frame switching are possible on each link between the AP MLD and non-AP MLDs.

[0063] Figure 1 An example of a wireless network 100 according to an embodiment is shown. Figure 1 The illustrated embodiment of the wireless network 100 is for illustrative purposes only. Other embodiments of the wireless network 100 may be used without departing from the scope of this disclosure.

[0064] like Figure 1 As shown, wireless network 100 may include multiple wireless communication devices. Each wireless communication device may include one or more stations (STAs). An STA may be a logical entity that is a separate addressable instance of an interface to the Media Access Control (MAC) layer and Physical (PHY) layer of the wireless medium. STAs may be classified as Access Point (AP) STAs and Non-Access Point (Non-AP) STAs. An AP STA may be an entity that provides access to a distribution system service to an associated STA via the wireless medium. A Non-AP STA may be a STA that is not included within an AP-STA. For simplicity, an AP STA may be referred to as an AP, and a Non-AP STA may be referred to as a STA. Figure 1 In the example, APs 101 and 103 are wireless communication devices, each of which may include one or more AP STAs. In such an embodiment, APs 101 and 103 may be AP multilink devices (MLDs). Similarly, STAs 111-114 are wireless communication devices, each of which may include one or more non-AP STAs. In such an embodiment, STAs 111-114 may be non-AP MLDs.

[0065] APs 101 and 103 communicate with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network. AP 101 provides wireless access to network 130 to multiple stations 111-114 in the coverage area 120 of AP 101. APs 101 and 103 can communicate with each other and with STAs using Wi-Fi or other WLAN communication technologies.

[0066] Depending on the network type, other well-known terms may be used instead of "access point" or "AP," such as "router" or "gateway." For convenience, the term "AP" is used in this disclosure to refer to a network infrastructure component that provides wireless access to remote terminals. In a WLAN, assuming that the AP also contends for the wireless channel, the AP may also be referred to as a STA. Furthermore, depending on the network type, other well-known terms may be used instead of "station" or "STA," such as "mobile station," "subscriber station," "remote terminal," "user equipment," "wireless terminal," or "user device." For convenience, the terms "station" and "STA" are used in this disclosure to refer to a remote wireless device that wirelessly accesses an AP or contends for a wireless channel in a WLAN, whether the STA is a mobile device (such as a mobile phone or smartphone) or is generally considered a fixed device (such as a desktop computer, AP, media player, fixed sensor, television, etc.).

[0067] exist Figure 1 In the diagram, the dashed lines indicate the approximate extent of the coverage areas 120 and 125 of APs 101 and 103, which are shown as approximately circular for illustrative and explanatory purposes. It should be clearly understood that, depending on the configuration of the APs, the coverage areas associated with the APs (such as coverage areas 120 and 125) may have other shapes, including irregular shapes.

[0068] As described in more detail below, one or more of the APs may include circuitry and / or procedures for managing MU-MIMO and OFDMA channel detection in a WLAN. Although Figure 1 An example of a wireless network 100 is shown, but more details can be found on other wireless networks. Figure 1 Various modifications can be made. For example, wireless network 100 can include any number of APs and any number of STAs in any suitable arrangement. Furthermore, AP 101 can communicate directly with any number of STAs and provide them with wireless broadband access to network 130. Similarly, each AP 101 and 103 can communicate directly with network 130 and provide STAs with direct wireless broadband access to network 130. Additionally, AP 101 and / or 103 can provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0069] Figure 2a An example of AP 101 according to an embodiment is shown. Figure 2a The embodiment of AP 101 shown is for illustrative purposes, and Figure 1 AP 103 can have the same or similar configuration. However, APs have a wide variety of configurations, and Figure 2a This disclosure is not intended to limit the scope of any particular implementation of AP.

[0070] like Figure 2a As shown, AP 101 may include multiple antennas 204a-204n, multiple radio frequency (RF) transceivers 209a-209n, transmit (TX) processing circuitry 214, and receive (RX) processing circuitry 219. AP 101 may also include a controller / processor 224, a memory 229, and a backhaul or network interface 234. RF transceivers 209a-209n receive incoming RF signals from antennas 204a-204n, such as signals transmitted by STAs in network 100. RF transceivers 209a-209n down-convert the incoming RF signals to generate intermediate (IF) or baseband signals. The IF or baseband signals are sent to RX processing circuitry 219, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. RX processing circuitry 219 sends the processed baseband signals to controller / processor 224 for further processing.

[0071] TX processing circuit 214 receives analog or digital data (such as voice data, network data, email, or interactive video game data) from controller / processor 224. TX processing circuit 214 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceivers 209a-209n receive the processed baseband or IF signal from TX processing circuit 214 and up-convert the baseband or IF signal into an RF signal transmitted via antennas 204a-204n.

[0072] The controller / processor 224 may include one or more processors or other processing devices that control the overall operation of the AP 101. For example, the controller / processor 224 may control the RF transceivers 209a-209n, the RX processing circuitry 219, and the TX processing circuitry 214 to receive uplink signals and transmit downlink signals, based on well-known principles. The controller / processor 224 may also support additional functions, such as more advanced wireless communication capabilities. For example, the controller / processor 224 may support beamforming or directional routing operations, where outgoing signals from multiple antennas 204a-204n are weighted differently to effectively direct outgoing signals in a desired direction. The controller / processor 224 may also support OFDMA operations, where outgoing signals are assigned to different subsets of subcarriers from different receivers (e.g., different STAs 111-114). The controller / processor 224 may support a variety of other functions in the AP 101, including combining DLMU-MIMO and OFDMA in the same transmission opportunity. In some embodiments, the controller / processor 224 may include at least one microprocessor or microcontroller. The controller / processor 224 is also capable of executing programs and other processes, such as an operating system, residing in the memory 229. The controller / processor 224 can move data into or out of the memory 229 as needed for the execution process.

[0073] Controller / processor 224 is also coupled to backhaul or network interface 234. Backhaul or network interface 234 allows AP 101 to communicate with other devices or systems via a backhaul connection or over a network. Interface 234 can support communication via any suitable wired or wireless connection. For example, interface 234 can allow AP 101 to communicate with a larger network (such as the Internet) via a wired or wireless local area network or via a wired or wireless connection. Interface 234 can include any suitable structure supporting communication via a wired or wireless connection, such as Ethernet or an RF transceiver. Memory 229 is coupled to controller / processor 224. A portion of memory 229 can include RAM, and another portion of memory 229 can include RAM or other ROM.

[0074] As described in more detail below, AP 101 may include circuitry and / or procedures for managing the channel detection process in a WLAN. Although Figure 2a An example of AP 101 is shown, but it is possible to compare it with other versions. Figure 2a Various changes can be made. For example, AP101 can include any number of... Figure 2aEach component shown. As a specific example, the AP may include multiple interfaces 234, and the controller / processor 224 may support routing functionality to route data between different network addresses. As another example, although shown as a single instance including TX processing circuitry 214 and a single instance including RX processing circuitry 219, AP 101 may include multiple instances of each (e.g., one per RF transceiver). Alternatively, only one antenna and RF transceiver path may be included, as in a conventional AP. Furthermore, Figure 2a The various components can be combined, further subdivided, or omitted, and additional components can be added as needed.

[0075] like Figure 2a As shown, in some embodiments, AP 101 may be an AP MLD comprising multiple APs 202a-202n. Each AP 202a-202n is attached to AP MLD 101 and includes multiple antennas 204a-204n, multiple radio frequency (RF) transceivers 209a-209n, transmit (TX) processing circuitry 214, and receive (RX) processing circuitry 219. Each AP 202a-202n may communicate independently with the controller / processor 224 and other components of AP MLD 101. Figure 2a The diagram shows that each AP 202a-202n has multiple antennas individually, but each AP 202a-202n can share multiple antennas 204a-204n without requiring separate multiple antennas. Each AP 202a-202n can represent the physical (PHY) layer and the lower media access control (MAC) layer.

[0076] Figure 2b An example of STA 111 according to an embodiment is shown. Figure 2b The embodiment of STA 111 shown is for illustrative purposes, and Figure 1 STAs 111-114 can have the same or similar configurations. However, STAs appear in a wide variety of configurations, and Figure 2b This disclosure is not intended to limit the scope of any particular implementation of STA.

[0077] like Figure 2b As shown, STA 111 may include an antenna 205, an RF transceiver 210, a TX processing circuit 215, a microphone 220, and an RX processing circuit 225. STA 111 may also include a speaker 230, a controller / processor 240, an input / output (I / O) interface (IF) 245, a touchscreen 250, a display 255, and a memory 260. The memory 260 may include an operating system (OS) 261 and one or more applications 262.

[0078] RF transceiver 210 receives incoming RF signals transmitted by the AP of network 100 from antenna 205. RF transceiver 210 down-converts the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are sent to RX processing circuitry 225, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. RX processing circuitry 225 sends the processed baseband signals to speaker 230 (e.g., for voice data) or to controller / processor 240 for further processing (e.g., for web browsing data).

[0079] TX processing circuitry 215 receives analog or digital voice data from microphone 220, or other outgoing baseband data (such as web data, email, or interactive video game data) from controller / processor 240. TX processing circuitry 215 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceiver 210 receives the processed outgoing baseband or IF signal from TX processing circuitry 215 and up-converts the baseband or IF signal into an RF signal transmitted via antenna 205.

[0080] The controller / processor 240 may include one or more processors and executes a basic OS program 261 stored in memory 260 to control the overall operation of STA 111. In one such operation, the controller / processor 240 controls the RF transceiver 210, RX processing circuitry 225, and TX processing circuitry 215 to receive downlink signals and transmit uplink signals according to well-known principles. The controller / processor 240 may also include processing circuitry configured to provide management of the channel detection process in the WLAN. In some embodiments, the controller / processor 240 may include at least one microprocessor or microcontroller.

[0081] The controller / processor 240 is also capable of executing other processes and programs residing in the memory 260, such as operations for managing channel sensing processes in the WLAN. The controller / processor 240 can move data into or out of the memory 260 as needed for the execution of the process. In some embodiments, the controller / processor 240 is configured to execute multiple applications 262, such as applications for channel sensing, including feedback calculations based on received Null Data Packet Advertisements (NDPA) and Null Data Packets (NDP), and sending beamforming feedback reports in response to trigger frames (TF). The controller / processor 240 can operate the multiple applications 262 based on the OS program 261 or in response to signals received from the AP. The controller / processor 240 is also coupled to an I / O interface 245, which provides the STA 111 with the ability to connect to other devices such as laptops and handheld computers. The I / O interface 245 is the communication path between these accessories and the main controller / processor 240.

[0082] The controller / processor 240 is also coupled to input 250 (such as a touchscreen) and display 255. An operator of STA 111 can use input 250 to input data into STA 111. Display 255 may be a liquid crystal display, a light-emitting diode display, or other display capable of displaying text and / or at least limited graphics (such as from a website). Memory 260 is coupled to the controller / processor 240. A portion of memory 260 may include random access memory (RAM), and another portion of memory 260 may include RAM or other read-only memory (ROM).

[0083] although Figure 2b An example of STA 111 is shown, but it is possible to compare it with other models. Figure 2b Make various changes. For example, Figure 2b The various components can be combined, further subdivided, or omitted, and additional components can be added as needed. In a specific example, STA 111 may include any number of antennas 205 for MIMO communication with AP 101. In another example, STA 111 may not include voice communication, or the controller / processor 240 may be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Furthermore, although... Figure 2b The STA 111 is shown configured as a mobile phone or smartphone, but the STA can be configured to operate as other types of mobile or fixed devices.

[0084] like Figure 2bAs shown, in some embodiments, STA 111 may be a non-AP MLD comprising multiple STAs 203a-203n. Each STA 203a-203n is attached to the non-AP MLD 111 and includes an antenna 205, an RF transceiver 210, a TX processing circuit 215, and an RX processing circuit 225. Each STA 203a-203n may independently communicate with the controller / processor 240 and other components of the non-AP MLD 111. Figure 2b It is shown that each STA 203a-203n has a separate antenna, but each STA 203a-203n can share antenna 205 without requiring a separate antenna. Each STA 203a-203n can represent the physical (PHY) layer and the lower media access control (MAC) layer.

[0085] Figure 3 An example of multi-link communication operation according to an embodiment is shown. Multi-link communication operation can be used in the IEEE 802.11be standard and any future revisions of the IEEE 802.11 standard. Figure 3 In the middle, AP MLD 310 can be Figure 1 Wireless communication devices 101 and 103, and non-AP MLD 220 can be Figure 1 One of the wireless communication devices 111-114 in the series.

[0086] like Figure 3 As shown, AP MLD 310 may include multiple affiliated APs, such as AP 1, AP 2, and AP 3. Each affiliated AP may include a PHY interface to the wireless medium (Link 1, Link 2, or Link 3). AP MLD 310 may include a single MAC Service Access Point (SAP) 318 through which the affiliated APs of AP MLD 310 communicate with higher layers (Layer 3 or network layer). Each affiliated AP of AP MLD 310 may have a different MAC address (lower MAC address) than any other affiliated AP of AP MLD 310. AP MLD 310 may have an MLD MAC address (upper MAC address), and the affiliated APs share the single MAC SAP 318 to Layer 3. Therefore, the affiliated APs share a single IP address, and Layer 3 identifies AP MLD 310 by assigning a single IP address.

[0087] A non-AP MLD 320 may include multiple affiliated STAs, such as STA 1, STA 2, and STA 3. Each affiliated STA may include a PHY interface to the wireless medium (Link 1, Link 2, or Link 3). A non-AP MLD 320 may include a single MAC SAP 328, through which affiliated STAs communicate with higher layers (Layer 3 or network layer). Each affiliated STA of a non-AP MLD 320 may have a different MAC address (lower MAC address) than any other affiliated STA of the non-AP MLD 320. A non-AP MLD 320 may have an MLD MAC address (upper MAC address), and the affiliated STAs share the single MAC SAP 328 to Layer 3. Therefore, affiliated STAs share a single IP address, and Layer 3 identifies the non-AP MLD 320 by assigning this single IP address.

[0088] AP MLD 310 and non-AP MLD 320 can establish multiple links between their associated APs and STAs. In this example, AP 1 and STA 1 can establish Link 1, operating in the 2.4 GHz band. Similarly, AP 2 and STA 2 can establish Link 2, operating in the 5 GHz band, and AP 3 and STA 3 can establish Link 3, operating in the 6 GHz band. Each link can independently enable channel access and frame switching between AP MLD 310 and non-AP MLD 320, which can increase data throughput and reduce latency. When associated with an AP MLD on a set of links (link establishment), each non-AP device is assigned a unique Association Identifier (AID).

[0089] The following documents are incorporated herein by reference in their entirety, as if fully set forth herein: 1) IEEE 802.11-2020, “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications”; 2) IEEE 802.11ax-2021, “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications”; 3) IEEE P802.11be / D4.0, “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications”.

[0090] Prior to the IEEE 802.11n standard (up to 802.11g), WiFi devices were allowed to use operating bandwidths up to 20MHz. Since IEEE 802.11n, the concept of channel bonding has been introduced to improve throughput, where wireless devices can opportunistically bond a non-primary channel with a primary 20MHz channel to transmit packets with higher bandwidth. IEEE 802.11n considered bonding up to 40MHz. IEEE 802.11ac extended channel bonding to 80 and 160MHz. IEEE 802.11ax extended channel bonding to 160MHz and introduced the idea of ​​puncturing. IEEE 802.11be introduced channel bonding up to 320MHz and further developed the puncturing concept to more configurations. The benefits of channel bonding can be twofold. Specifically, if adjacent BSSs are idle, there is a clear benefit of increased throughput. If adjacent BSSs are busy, channel bonding can prevent adjacent BSSs from accessing the channel by taking away their primary channel. Therefore, channel bonding can improve transmission efficiency (and thus increase throughput) at the cost of increased latency.

[0091] Using channel bonding, an access point (AP) can support one or more of the following maximum operating bandwidths (BW): X = 20, 40, 80, 160, or 320 MHz. The AP can use one or more operating elements transmitted by the AP to indicate the parameters of its current operating channel. Operating elements can include Very High Throughput (VHT), High Efficiency (HE), or Extremely High Throughput (EHT) operating elements.

[0092] Figure 4 An EHT operation element transmitted by an AP according to an embodiment is shown. The EHT operation element may include an element ID field, a length field, an element ID extension field, an EHT operation parameter field, a basic EHT-MCS and NSS set field, and an EHT operation information field. The EHT operation information field may include a control field, a CCFS0 field, a CCFS1 field, and a disabled sub-channel bitmap field. The control field may include a channel width field and a reserved field.

[0093] The Element ID field provides an identifier for the element. The Length field can include the element's length information. The Element ID Extension field can include extended information about the element. The EHT Operation Parameters field can include the element's operation parameters. The Basic EHT-MCS and NSS Set fields can include the element's MCS and NSS information. The EHT Operation Information field can include the element's operation information.

[0094] The control field can include control information for the element and may include a channel width field and a reserved field. The channel width field provides channel width information and can define the EHT BSS bandwidth. The reserved field can be reserved.

[0095] The CCFS0 field can define the channel center frequency for 20, 40, and 80 MHz EHT BSSs, the primary 80 MHz channel for a 160 MHz EHT BSS, or the primary 160 MHz channel for a 320 MHz EHT BSS. The CCFS1 field can define the channel center frequency for a 160 or 320 MHz EHT BSS. A disabled subchannel bitmap can provide bitmap information for disabled subchannels. The AP can include these operational elements in beacon and / or probe response frames, and these elements can include: (i) a channel width subfield indicating the maximum BSS bandwidth X, (ii) a channel center frequency segment (CCFS) 0 field indicating the center frequency of the primary X / 2 MHz channel of the BSS, and (iii) a CCFS 1 field indicating the center frequency of the X MHz channel.

[0096] Although the operating element indicates the maximum supported bandwidth of the AP, the AP can also support STAs with smaller operating bandwidths. In practice, due to power consumption and cost reasons, STAs can typically support even smaller bandwidths than the AP. EHT APs / STAs can declare the channel widths they can operate on in the PHY capability information field of the HT / VHT / HE / EHT capability element they transmit in beacon and probe response frames.

[0097] Figure 5 The VHT capability elements according to an embodiment are shown. The number of spatial streams (NSS) that can be supported at all BWs is indicated in the Supported MCS and NSS set fields. The NSS supported by each BW is identified from the "Supported Channel Width Set" + "Extended NSS BW Support" fields. When serving a STA with a bandwidth smaller than X MHz than the AP, if the non-AP STA has not yet established a Sub-Channel Specific Transport (SST), the AP does not allocate resource units (RUs) outside the primary X MHz in the HE MU PPDU or HE TB PPDU to the STA.

[0098] Specifically, a VHT capability element may include an element ID field, a length field, a VHT capability information field, and a supported VHT-MCS and NSS set field. The element ID field provides an identifier for the element. The length field provides the element's length information. The VHT capability information field provides the element's capability information and may include several subfields as described below. The supported VHT-MCS and NSS set field provides information about the NSSs that can be supported at all BW locations.

[0099] The VHT capability information field may include several subfields, including: maximum MPDU length field, supported channel width set field, RX LDPC field, short GL field for 160 and 80+80MHz, Tx STBC field, Rx STBC field, SU beamformer capability field, SU beamformer receiver (Beamformee) capability field, beamformer receiver STA capability field, number of probe dimensions field, MU beamformer capability field, MU beamformer receiver capability field, TXOP PS field, +HTC-VHT capability field, maximum A-MPDU length exponent field, VHT link adaptive capability field, and Rx antenna orientation. Figure 1 Consistency field, Tx antenna direction Figure 1 Consistency field, Tx antenna direction Figure 1 Consistent fields and extended NSS BW supported fields.

[0100] The Maximum MPDU Length field provides information about the maximum length of the MPDU. The Supported Channel Width Set field provides information about the supported channel width sets.

[0101] The RxLDPC field provides information about the receiver's low-density parity (LDPC) and can be set to 1 if the transmitter is able to receive LDPC-encoded frames.

[0102] The short GI in the 4C field of the 80MHz / TVHT mode provides information about the short guard interval and can be set to 1 if the transmitter can receive frames transmitted using the short guard interval with the indicated channel bandwidth.

[0103] The short GI in the 160 and 80+80MHz fields can provide information about the short guard interval and can be set to 1 if the transmitter is able to receive frames transmitted using the short guard interval with the indicated channel bandwidth.

[0104] The Tx STBC field can be set to 1 to indicate the transmission of frames that support STBC encoding.

[0105] The Rx STBC field describes how many spatial streams are supported for the reception of STBC-encoded frames. It can be set to 0, 1, 2, 3, or 4, describing the maximum number of spatial streams supported during reception. To support a spatial stream, this field can take the value 1. A value of 0 can be used to indicate that STBC is not supported, and values ​​5-7 can be reserved.

[0106] The Single User (SU) Beamformer Capability field, when set to 1, indicates that the transmitter is capable of operating as a single user beamformer to exchange packets with another station.

[0107] The SU beamforming receiver capability field, when set to 1, indicates that the transmitter can operate as a single-user beamforming receiver that exchanges packets with another station.

[0108] The beamforming receiver STS capability field can provide information about the beamforming receiver's STA capabilities.

[0109] The probe dimension number field can be used in beamforming channel measurement procedures to indicate the maximum number of antennas that can participate in channel measurements.

[0110] The MU beamformer capability field provides information about the capabilities of the MU beamformer.

[0111] The MU beamforming receiver capability field provides information about the capabilities of the MU beamforming receiver.

[0112] The TXOP PS field is the TXOP Power Saving (PS) field, where an AP can set this bit to 1 to enable power saving operation during VHT transmission bursts, or set it to 0 to disable them. A station associated with the network sets this bit to 1 to indicate that the capability is enabled, or sets it to 0 if the capability is disabled.

[0113] The +HTC-VHT capability field can be set to 1 to indicate that the transmitter is capable of receiving VHT variant HT control fields.

[0114] The maximum A-MPDU length index field can take values ​​from 0 to 7 and can be used to transmit the size of the A-MPDU that can be sent.

[0115] The VHT Link Adaptive Capability field can be used for link adaptive feedback to select the most suitable MCS for the link using explicit feedback.

[0116] If the transmitter's antenna pattern does not change after the association is completed, then the Rx antenna direction... Figure 1 The consistency field can be set to 1, otherwise it can be set to 0.

[0117] If the transmitter's antenna pattern does not change after the association is completed, then the Tx antenna direction... Figure 1 The consistency field can be set to 1, otherwise it can be set to 0.

[0118] The extended NSS BW support field can provide extended NSS BW support information.

[0119] To support trigger-based communication, several trigger frames have been proposed in IEEE 802.11ax. Two prominent trigger frames are described below.

[0120] A Multi-User Request Transmission (MU-RTS) trigger frame is introduced to request a Clear-To-Send (CTS) response from at least one of the multi-user capable STAs addressed by the MU-RTS frame. This can be beneficial for detecting hidden node situations in multi-user transmission frames. MU-RTS is transmitted as a broadcast frame and is typically in the traditional non-HT repeated Physical Protocol Data Unit (PPDU) format, allowing all STAs to decode it. The MU-RTS-CTS process is used to prevent hidden node problems and to reserve channels for MU transmissions. In each 20 MHz channel of Winning Transmission Opportunity (TXOP), the AP sends an MU-RTS trigger and requests that at least one non-AP STA should respond with a CTS on each such 20 MHz channel.

[0121] Figure 6 The MU-RTS trigger frame format according to an embodiment is shown. For example... Figure 6 As shown, the MU-RTS has a common information field and a user information field. The common information field indicates parameters common to all addressed STAs, such as the TXOP bandwidth and how each STA should respond to the MU-RTS frame. The user information field includes RU allocations to one or more AIDs. Bits B0-B7 of the RU allocation indicate the location on the X MHz main channel where the CTS should be transmitted. After successfully receiving the CTS, the AP can transmit a HE TBPPDU.

[0122] The UL BW field of the Common Information Field of the MU-RTS indicates the BW of subsequent TB PPDUs. The AP waits for the CTSTimeout interval to see if a response is received. If no response is received, the AP assumes that the MU-RTS has failed and can initiate PIFS recovery or back off. When the STA responds to the MU-RTS, it is expected that the transmission start time of the response frame will be within ±0.4μs + 16μs at the STA's transmit antenna connector from the end of the last OFDM symbol that triggered the PPDU (if it does not contain a PE field) or the end of the PE field of the triggering PPDU (if the PE field exists). The responding STA also needs to compensate for the carrier frequency offset (CFO) error and symbol clock error related to the triggering PPDU when transmitting the response. For the MU-RTS frame, the corrected residual CFO should be below 2kHz.

[0123] exist Figure 6 In the MU-RTS trigger frame, there are Frame Control Field, Duration Field, Receiver Address (RA) Field, Transmitter Address (TA) Field, Common Information Field, User Information List Field, Padding Field, and FCS Field.

[0124] The Frame Control field provides frame control information for the frame, including version, type, subtype, and other information. The Duration field provides duration information. The RA field provides the address of the receiving STA. The TA field provides the address of the sending STA. The Common Information field provides parameters common to all addressed STAs and includes various subfields as described below. The User Information List field provides RU allocation to one or more AIDs and includes several subfields as described below.

[0125] Public information fields may include trigger type field, UL length field, more TF field, CS requirement field, ULBW field, GI and HE-LTF type field, MU-MIMO HE-LTF mode field, HE-LTF symbol number and mid-leader periodicity field, UL STBC field, LDPC extra symbol segment field, AP TX power field, FEC pre-padding factor field, PE disambiguation field, UL space reuse field, Doppler field, UL HE-SIG-A 2 reserved field and reserved field.

[0126] The user information list fields may include the AID12 field, RU allocation field, UL FEC coding type field, ULHE-MCS field, UL DCM field, SS allocation / RA-RU information field, UL target received power field, and reserved fields.

[0127] The Trigger Type field provides information about the type of trigger frame. The UL Length field provides length information. The More TF field provides more information about trigger frames. The CS Requirement field enables / disables CS requirements. When set to On, it indicates that each STA identified in the User Information field needs to use Energy Detection (ED) to sense the medium and consider medium state and NAV when determining whether to respond. The CS Requirement subfield is set to Off to indicate that STAs identified in the User Information field do not need to consider medium state or NAV when determining whether to respond.

[0128] The UL BW field sets the bandwidth of the PPDU. The GI and HE-LTF type fields set the GI and LTF types of the PPDU. The MU-MIMO HE-LTF mode field provides LTF mode information. The HE-LTF symbol count and mid-prefix periodicity fields set the number of LTF symbols present in the HE-triggered PPDU response. The UL STBC field enables / disables STBS encoding for the HE-triggered PPDU response. The LDPC extra symbol segment field enables / disables the LDPC extra symbol segment. It can be set to On when the LDPC extra symbol segment is present, and Off otherwise. The AP TX power field sets the combined average power per 20MHz bandwidth of all transmit antennas used to transmit the trigger frame at the HE AP. Values ​​from 0 to 60 map to -20dBm to 40dBm with 1dB resolution. The FEC pre-padding factor field provides padding factor information. The PE disambiguation field provides disambiguation information. The UL spatial reuse field sets the value of the spatial reuse field in the HE-SIG-A field of the HE-triggered PPDU transmitted as a response to the trigger frame. The Doppler field can indicate a high-Doppler transmission mode. The UL HE-SIG-A2 reserved field can set the value of the reserved bits in the HE-SIG-A2 of the HE-triggered PPDU sent in response to a trigger frame. Reserved fields can be reserved. The user information list field may include several subfields as described.

[0129] The AID12 field sets the least significant 12 bits of the AID for the STA to which the User Information field corresponds. The RU Allocation field sets the RU allocation used by the HE-triggered PPDU for the STA identified by the AID12 subfield. The UL FEC Encoding Type field sets the code type of the HE-triggered PPDU response for the STA identified by the AID12 subfield; 0 for BCC and 1 for LDPC. The UL HE-MCS field sets the MCS of the HE-triggered PPDU response for the STA identified by the AID12 subfield. The UL DCM field sets the dual-carrier modulation of the HE-triggered PPDU response for the STA identified by the AID12 subfield. The SS Allocation / RA-RU Information field sets the spatial stream of the HE-triggered PPDU response for the STA identified by the AID12 subfield; 3 bits are used for the initial spatial stream, and 3 bits are used for the spatial stream number. The UL Target Received Power field sets the target received signal power of the HE-triggered PPDU response for the STA identified by the AID12 subfield. Reserved fields can be reserved.

[0130] Subchannel Specific Transmission (SST) is an optional feature for both APs and non-AP STAs introduced in the IEEE 802.11-2020 standard. It allows non-AP STAs to negotiate operation on a specific frequency band during a Triggered Target Wake-Up Time (TWT) scheduling period. TWT requests / responses can use the TWT channel field to indicate the requested subchannel for RU allocation to a HE SST non-AP STA operating as an X MHz STA. During SP, the non-AP STA should be available in the subchannel indicated in the TWT channel field of the TWT response at the TWT start time and should not use DCF or EDCAF access media in the subchannel; that is, it can only be triggered by the AP. HE SST non-AP STAs can include a channel handover timing element in their (re)association request frames sent to the HE SST AP to indicate the time required for the STA to handover between different subchannels. The received channel handover time notification HE SSTP indicates the duration for which the HE SST non-AP STA may not receive frames before the TWT start time and after the end of the Triggered Target Wake-Up Time (TWT) SP.

[0131] Figure 7The Buffer Status Report Polling (BSRP) trigger frame format according to an embodiment is illustrated. A BSRP trigger frame is introduced to trigger an uplink response from one or more multi-user capable STAs addressed by the BSRP frame via OFDMA. This response may include an uplink buffer status report corresponding to a different service class at the responding STA. This response may be useful for the triggering device to subsequently allocate uplink resources for its trigger-based uplink transmissions to the responding STA. Each STA addressed in the BSRP has a corresponding user information field in the BSRP, and the RU allocation field of the user information field indicates the set of resource elements (RUs) on which the STA expects to transmit the response frame. When an STA responds to the BSRP, it is anticipated that the transmission start time of the response frame will be within ±0.4 μs + 16 μs from the end of the last OFDM symbol of the triggering PPDU (if it does not include the PE field) or the end of the PE field of the triggering PPDU (if the PE field is present) at the STA's transmit antenna connector. The responding STA also needs to compensate for carrier frequency offset (CFO) errors and symbol clock errors related to the triggering PPDU when transmitting the response. For BSRP frames, the corrected residual CFO should be below 300Hz.

[0132] For newer WiFi generations, the maximum bandwidth supported by the specifications has increased to improve throughput. For example, using IEEE 802.11be, a maximum bandwidth of 320MHz can be supported via channel bonding. However, non-AP STAs can typically operate with a much smaller bandwidth (e.g., 80MHz). This is likely due to cost and power considerations, and also because the 320MHz bandwidth may not always be available due to transmissions from neighboring devices. This can reduce the efficiency of the AP, because even if it wins a channel on 320MHz, it cannot utilize it, as all 80MHz STAs can be served on the primary 80MHz channel, such as... Figure 8 As shown.

[0133] Specifically, Figure 8An example of wasted BSS bandwidth is shown according to an embodiment when all associated STAs support narrow bandwidth. To enable the AP to utilize its full 320 MHz bandwidth (when it can win channel access for itself) while allowing STAs to operate on smaller bandwidths, the concept of Dynamic Subband Operation (DSO) was proposed in discussions of IEEE 802.11bn. Specifically, the BSS BS supports 320 MHz bandwidth; however, each of STA1, STA2, STA3, STA4, and STA5 uses only the same 80 MHz bandwidth. As indicated, the primary channel is 20 MHz, and each box represents a 20 MHz bandwidth. Therefore, beyond the utilized 80 MHz bandwidth, there is a remaining 160 MHz of wasted bandwidth and an additional 80 MHz of wasted bandwidth. Mechanisms to address this problem could include situations where a non-AP MLD can perform Dynamic Subband Operation (DSO), whereby it can switch to a new subchannel outside its initial operating bandwidth upon receiving a request from the AP.

[0134] Figure 9 The DSO subband handover operation according to an embodiment is illustrated. The DSO device is a limited-bandwidth device that can switch to a specific subband of the AP's operating channel as needed. Therefore, when winning a TXOP for 320MHz, the AP can instruct different DSO capability STAs to switch to different 80MHz subbands jointly occupying the entire 320MHz in a Subband Handover Initial Control (SBS IC) frame. After a sufficient delay, the AP initiates a transmission to the DSO STA on its designated subband to allow the DSO device to perform the channel handover. The AP also ensures that the TXOP is protected for its duration. At the end of the TXOP, the DSO STA switches back to the primary channel.

[0135] Recently, discussions regarding IEEE 802.11bn have also addressed several other characteristics involving devices frequently changing their operating channels or bandwidths. Prior to the introduction of Non-Primary Channel Access (NPCA), based on baseline operation, an AP or associated non-AP STA could transmit on any non-primary channel within the BSS bandwidth, if it also transmitted on the primary 20MHz channel. If the primary channel was busy due to OBSS TXOP, transmission was impossible even if an idle secondary channel existed. This could increase channel access latency and reduce channel utilization efficiency. As a solution, a mechanism for Non-Primary Channel Access (NPCA) has been proposed. When an AP enables NPCA operation, it can also expose one or more alternate 20MHz primary channels. If OBSS transmissions occupy an AP's primary channel for a certain Network Allocation Vector (NAV) duration, the NPCA-enabled AP and associated non-AP STA can switch to one of the alternate primary channels to perform frame switching, treating that alternate channel as a temporary primary channel until the NAV duration on the primary primary channel ends. During this time, transmissions can still be confined within the BSS bandwidth. AP and non-AP STAs can return to the main channel before the NAV duration ends.

[0136] Dynamic Power Saving (DPS) operation has been proposed to save power consumption for APs or non-AP STAs and minimize performance degradation for latency-sensitive services. In DPS mode, by default, APs or non-AP STAs can operate with reduced capabilities (e.g., reduced channel width, support for limited Physical Protocol Data Unit (PPDU) formats, reduced MCS sets, and NSS sets). APs or non-AP STAs can operate with reduced capabilities for receiving, transmitting, or both. Operating with reduced capabilities allows APs or non-AP STAs to save power. However, upon receiving a request within a TXOP, an AP or non-AP STA can increase one or more of its supported bandwidth (BW), supported PPDU formats, MCS sets, and NSS sets, at least for the duration of the TXOP. Therefore, after sending a request to an AP or non-AP STA for increased capabilities, the TXOP owner can perform communication for the remainder of the TXOP with enhanced channel width, PPDU formats, MCS sets, and NSS values. After the TXOP ends or after a predetermined amount of time from the end of the TXOP, the AP or non-AP STA can return to its reduced operating parameters. Peer STAs that do not support DPS can operate with the DPS AP or non-AP STA according to their reduced operating parameters, while peer STAs that support DPS can operate with the DPS AP or non-AP STA according to their reduced operating parameters, or they can operate with the enhanced operating parameters of the AP or non-AP STA after sending a request to the AP or non-AP STA to switch.

[0137] IEEE 802.11be supports multiple operating frequency bands, where access points (APs) and non-AP devices can communicate with each other, referred to as links. Therefore, both APs and non-APs can communicate on different frequency bands / links, a phenomenon known as multi-link operation (MLO). Devices capable of MLO operation are called multi-link devices (MLDs). To improve channel access capability in MLO devices with limited hardware cost and power consumption, IEEE 802.11be also supports an operating mode for non-AP MLD devices called Enhanced Multi-Link Single Radio (EMLSR) mode. In EMLSR mode, the non-AP device behaves like a single radio device, capable of performing channel sensing and basic packet reception simultaneously on multiple frequency bands / links, but reliably performing data communication on only one link at a time. Therefore, by opportunistically selecting the link that wins channel contention for data communication, EMLSR can improve system spectral efficiency. The operation procedure for EMLSR links is defined in the current 802.11be standard draft and, according to embodiments, is... Figure 10aAs shown in the diagram. In recent discussions regarding 802.11bn, an extension to this mechanism has also been proposed to support EMLSR operation for single-link devices, referred to as Single-Link EMLSR Operation. Note that Single-Link EMLSR Operation is identical to DPS Operation for non-AP STAs.

[0138] To improve spectral efficiency by timely enhancing supported MCS and NSS, IEEE 802.11be also supports an operating mode for non-AP MLD devices called Enhanced Multi-Link Multi-Radio (EMLMR) mode. When a frame exchange sequence with an AP begins on the first link, a non-AP MLD in EMLMR mode can move a radio from its other links to the first link to improve the supported MCS and NSS on that link. The set of links that have this ability to move radios to / from an EMLMR non-AP MLD is called an EMLMR link. The operating procedure for a non-AP MLD in EMLMR mode is defined in the current 802.11be standard draft and, according to embodiments, is... Figure 10b As shown in the image.

[0139] According to embodiments of this disclosure, a BSS with an AP and one or more associated STAs can be assumed. The AP may support a wider maximum BSS bandwidth than some of the associated STAs. The AP and some STAs may support Dynamic Subchannel Operation (DSO). In DSO, upon winning channel access, at the beginning of a TXOP, the AP may provide the DSO STAs with an indication of the subbands they intend to serve within the TXOP or SP. In some embodiments, the subband may be, for example, a 20MHz channel or resource element (RU), which is a portion of the frequency for which channel access has been won, and may even be outside the primary channel being listened to by the STA. In some embodiments, the subband may also be referred to as a subchannel. Upon receiving this indication, the indicated STA may switch to the indicated subband for the remainder of the TXOP or SP to receive frames from the AP. This mechanism can help to efficiently utilize the full BSS bandwidth of the AP when the associated STAs support a smaller bandwidth. In some embodiments, the AP may also be a multi-link device, and some DSO STAs may also be able to operate in EMLSR or EMLMR modes. Although several embodiments of SBS IC frames being MU-RTS frames are provided herein, this should not be considered as a limitation of this disclosure. Similar fields can also be used in other options of the SBS IC frame, such as the Block Ack Request (BAR) frame, the Buffer Status Report Polling (BSRP) frame, and other frames and their corresponding response frames. Embodiments of this disclosure can be applied to other device modes involving changes in the operating bandwidth of the device, such as dynamic power-saving operation, single-link enhanced multi-link multi-radio operation, or non-master channel access operation, and other operations.

[0140] Although several embodiments of the UHR generation of the Wi-Fi standard have been described according to this disclosure, the embodiments according to this disclosure may be applied to other versions of different standards, including the IEEE Wi-Fi standard and non-Wi-Fi standards (e.g., Wi-Fi Sensing, Wi-Fi Direct, etc.).

[0141] This document describes the SBS IC frame format according to some embodiments. In some embodiments, when winning a wide bandwidth TXOP, it may be desirable to serve DSO clients on the secondary channel and non-DSO clients on the primary channel.

[0142] Figure 11 Examples of serving a DSO device on a secondary channel and serving a non-DSO STA on a primary channel, according to embodiments, are shown. Specifically, Figure 11 The diagram illustrates the service of DSO devices on the secondary 80MHz channel and non-DSO STAs on the primary 80MHz channel within a 160MHz TXOP. As shown, the DSO devices include STA1, STA2, STA3, STA4, STA5, and STA6.

[0143] In some embodiments, if an SBS IC frame request response is received, both the DSO and non-DSO devices should respond to ensure full-bandwidth TXOP protection. In some embodiments, it may be desirable to design the SBS IC with a frame format that can also request responses from 11bn-previous devices.

[0144] In some embodiments, the MU-RTS frame can be used as the SBS IC frame of the DSO device. Figure 12a The common information fields of a MU-RTS frame as an SBS IC according to an embodiment are shown. The MU-RTS frame includes a frame control field, a duration field, a receiver address (RA) field, a transmitter address (TA) field, a common information field, a user information list field, a padding field, and a frame check sequence (FCS) field. The common information fields include a trigger type field, a pre-FCS location field, a more TF field, a CS requirement field, a UL BW field, a DSO include field, and one or more reserved fields.

[0145] The Frame Control field provides frame control information for a frame, including version, type, subtype, and other information. The Duration field provides duration information. The RA field provides the address of one or more receiving STAs. The TA field provides the address of the sending STA. The Common Information field provides parameters common to all addressed STAs and includes various subfields as described below. The User Information List field provides RU allocation to one or more AIDs and includes several subfields as described below. The Padding field provides padding information. The FCS (Frame Control Sequence) field provides error detection information.

[0146] The Trigger Type field provides information about the type of trigger frame. The More TF field provides information about whether there are more subsequent trigger frames. The CS Requirement field enables / disables the CS requirement. Setting it to On indicates that the STA identified in the User Information field needs to use ED to sense the medium and consider medium state and NAV when determining whether to respond. Setting the CS Requirement subfield to Off indicates that the STA identified in the User Information field does not need to consider medium state or NAV when determining whether to respond. The UL BW field sets the bandwidth of the PPDU. The Reserved field is reserved.

[0147] Subsequent attached figures (including) Figure 12b , Figure 13 , Figures 14a-14f Some fields shown in Figures 24 and 25 can be compared with those in the previous figures (including...). Figure 12a The fields described in the figure are the same as those in the figure below, and their descriptions are omitted in the subsequent figures.

[0148] Figure 12b Another example of the common information field of the MU-RTS frame as an SBS IC according to an embodiment is shown. Figure 12b In a MU-RTS frame, the frame control field, duration field, receiver address (RA) field, transmitter address (TA) field, common information field, user information list field, padding field, and frame check sequence (FCS) field are included. The common information field may include trigger type field, subtype field, reserved field, additional TF field, CS requirement field, UL BW field, Pre-FCS location field, and reserved field. In some embodiments, such a MU-RTS frame can also be used to address 11bn front-end devices. In some embodiments, the common information field and the reserved field of the user information field of the MU-RTS frame can be used to provide necessary information for DSO subband handover operations. The common information field may have, for example, […]. Figure 12a The “DSO includes” field shown, or as... Figure 12bThe “Subtype” field shown indicates that the MU-RTS frame is an SBS IC frame. Such a field can have a specific length (e.g., 1-4 bits), and a specific bit sequence can indicate the fact that the MU-RTS includes some DSO-specific user information fields.

[0149] Figure 13 The user information field of a MU-RTS frame as an SBS IC according to an embodiment is shown. The user information field may include an AID 12 field, an RU allocation field, a subtype field, a preamble detection channel field, a scheduling time field, and a reserved field.

[0150] In some embodiments, the user information list in the MU-RTS frame may have several user information fields, some of which may be DSO-specific user information fields. DSO-specific user information fields can be addressed to the DSO STA that the AP intends to request a subband handover to. Reserved fields in the user information fields of a regular MU-RTS frame can be used to indicate DSO parameters in the DSO-specific user information fields. One such parameter may be a "DSO-specific" field or a "subtype" field of a specific length (e.g., 1-4 bits), and a specific encoding of this field may indicate that the user information field is a DSO-specific field. Another DSO-specific parameter may be a scheduling time field, which may be set to "0" or "1" to indicate whether the AP intends to perform a frame exchange with the indicated STA immediately or later within the TXOP, respectively. In some embodiments, the STA with which the AP intends to perform a frame exchange immediately may need to respond to the MU-RTS frame. Yet another DSO-specific parameter may be a preamble detection channel field, which indicates a 20MHz temporary master channel where the DSO STA to be addressed performs preamble detection. In some embodiments, if a DSO STA is addressed by MU-RTS but is not expected to perform a subband handover (e.g., it is served on the main channel), then DSO-specific parameters may not be included in the user information field of the AID corresponding to that STA.

[0151] In some embodiments, when the RU allocation field indicates an RU outside the main channel, the user information field can be implicitly inferred to be a DSO-specific user information field. Accordingly, a subtype field or a DSO-specific field may not be required.

[0152] In some embodiments, a BAR frame or a BSRP trigger frame can be used as an SBS IC, and similar fields as described above can be used in the public information and user information fields to provide DSO-specific parameters.

[0153] In some embodiments, Frame Check Sequence (FCS) verification can be enabled simultaneously with the padding field. In some embodiments, after obtaining the subband allocation indication in the SBS IC frame, the DSO device can perform a channel handover to the indicated channel. To protect the radio medium while the DSO STA performs a channel handover, the AP can transmit some signals on the radio medium across all bands of the TXOP for a sufficient period of time.

[0154] In some embodiments, the SBS IC may not request a response from a non-AP STA and may provide the necessary padding for the handover in a subsequent frame sent later.

[0155] In some embodiments, when the SBS IC frame is a MU-RTS frame, the MU-RTS can be transmitted in an aggregation-enabled PPDU format, where a subsequent padding frame can be used in the A-MPDU as the medium reservation signal. In some embodiments, when the SBS IC frame is a MU-RTS frame, the medium reservation transmission on the medium can be the padding field of the MU-RTS frame. However, since the padding field precedes the Frame Check Sequence (FCS), if the DSO STA switches during the padding field, the DSO STA may not be able to receive the FCS field at the end of the frame to perform FCS verification.

[0156] In some embodiments, it may be expected that the DSO STA will perform subband switching without performing FCS verification on the MU-RTS frame.

[0157] In some embodiments, the AP may include a "Pre-FCS" field in the user information list of the MU-RTS frame or other trigger frames used as SBS IC frames, which can be used by the DSO device to perform frame verification. Since the user information list appears before padding, the DSO device can use this Pre-FCS verification field to perform frame verification and then perform subband switching during padding. The Pre-FCS field may also have other names, such as the Intermediate FCS (I-FCS) field.

[0158] Figure 14a The Pre-FCS field at the end of the user information list of the MU-RTS frame according to an embodiment is shown.

[0159] Figure 14b The Pre-FCS field at the end of the user information list, which includes the Pre-FCS identifier subfield, is shown according to an embodiment.

[0160] In some embodiments, a Pre-FCS field can be added at the end of all other user information fields of the STA addressing the expected response to MU-RTS. Traditional devices can interpret this Pre-FCS field as part of a fill or some unknown user information fields, which can be achieved, for example, by including a specific sequence at the beginning of the Pre-FCS field, such as... Figure 14b As shown. The FCS value of the Pre-FCS field can be calculated based on the bits preceding its position in the MU-RTS rather than the bits following it. In some embodiments, the Pre-FCS field can be 32 bits long, comprising a 32-bit FCS value. In some embodiments, the Pre-FCS field can be 40 bits long (similar to a traditional user information field), may include a 32-bit FCS value, but may not have an AID12 field. In some embodiments, the Pre-FCS field can be greater than or equal to 44 bits long, and may include an AID12 subfield or a Pre-FCS identifier subfield, which is assigned a special predetermined value (to aid in its identification) and a 32-bit FCS value. For example, according to an embodiment, as... Figure 14b As shown, the Pre-FCS identifier subfield can have a length of 2 octets set to all 1s to identify the beginning of the Pre-FCS field. This special sequence also helps conventional STAs interpret the Pre-FCS as part of the padding.

[0161] Figure 14c The Pre-FCS field, as part of two special user information fields in a MU-RTS frame according to an embodiment, is shown. In some embodiments, two adjacent user information fields in a MU-RTS frame can be used together to indicate a Pre-FCS value, such as... Figure 14cAs shown. In some embodiments, each of the two user information fields may have a normal length of 40 bits. The first 16 bits of the calculated FCS may be included in the first user information field, while the last 16 bits of the FCS value may be included in the second user information field. In some embodiments, the 32 bits of the FCS may be divided differently between the two user information fields (e.g., 28 bits in one field and 4 bits in the other). In some embodiments, the AID12 field of the user information field may be predetermined and may be from the AID range of 2008-2044 or 2047-4094. In some embodiments, two consecutive AID12 values ​​may be assigned to the user information field. In some embodiments, for efficiency, the two user information fields may share the same AID12 value. In several embodiments, the AP may determine the AID of these user information fields based on its implementation, and the AID may not correspond to any other associated STA. The FCS value of the Pre-FCS field may be calculated based on the bits preceding the two user information fields and the AID12 field of the first user information field, rather than based on the bits transmitted later in the MU-RTS frame. In some embodiments, these special user information fields may be included after all user information fields corresponding to the DSO device.

[0162] Figure 14d The Pre-FCS field is shown in the second of two special user information fields in a MU-RTS frame according to an embodiment. In some embodiments, two adjacent user information fields in a MU-RTS frame can be used together to indicate the Pre-FCS value, such as... Figure 14d As shown. In some embodiments, each of the two user information fields may have a normal length of 40 bits. In some embodiments, the AID12 values ​​of the two user information fields may be predetermined and may be from the AID range of 2008-2044 or 2047-4094. In some embodiments, the AP may determine the AID of the user information field based on its implementation or the value of the FCS remainder. The AID may not correspond to any other associated STA. The 12 bits of the AID12 field of the second user information field and the subsequent 20 bits of the second user information field may jointly indicate the Pre-FCS value. The FCS value of the Pre-FCS field may be calculated based on the bits preceding the second user information field. In some embodiments, the last 28 bits of the first user information field (after the AID12 field) may be reserved and configured to ensure that the first 12 bits of the Pre-FCS field match the value of the selected AID12 field of the second user information field.

[0163] In some embodiments, it can also be ensured that the main FCS value (including at the end of the frame) remains unchanged regardless of whether two special user information fields are included or excluded in the frame. This allows for parallel computation of the FCS and Pre-FCS values. This feature can be achieved by intelligently designing the reserved / unused bits of the two special user information fields, or by including a third special user information field after the two special user information fields and designing its bits. In some embodiments, the Pre-FCS value may be appended with 32 bits that match the 32-bit FCS remainder generated by the MAC frame using the bits preceding the two user information fields.

[0164] Figure 14e A short Pre-FCS field in a special user information field of a MU-RTS frame according to an embodiment is shown. In some embodiments, a single special user information field may be present for carrying the Pre-FCS. In some embodiments, the Pre-FCS polynomial may be selected as degree 32, but the highest valid 28 bits of the remainder (up to and including AID12 of the special user information field when performing FCS calculation on all bits of the MU-RTS frame) may be carried in the remaining 28 bits of the user information field. If the highest valid 28 bits of the FCS check remainder are all 0 (the last 4 bits of the remainder are ignored), the DSO receiver may accordingly declare the frame to be correct. In some embodiments, instead of the highest valid 28 bits, the lowest valid 28 bits may be carried in the Pre-FCS field. In some embodiments, the Pre-FCS polynomial may be selected to have a length of less than or equal to 28 bits, and therefore one special user information field may be sufficient for indication. For example, a 16-degree Pre-FCS polynomial may be used, and 16 bits of the 28 bits of the special user information field after the AID12 field may carry the Pre-FCS value, such as... Figure 14e As shown, according to one embodiment, this Pre-FCS value can be calculated based on all bits of the MAC frame preceding its position (including the AID12 field of the special user information field).

[0165] In some embodiments, the Pre-FCS field can be a new element of variable length, called an 11bn pre-filled element, and it can carry additional information in addition to the FCS value.

[0166] According to some embodiments, the position of the Pre-FCS field can be as follows: Figure 12a or Figure 12bThe “Pre-FCS Location” field shown is indicated in the common information field of the MU-RTS frame. In some embodiments, if a Pre-FCS field exists after f(n) user information fields, the location of the Pre-FCS field can be indicated by carrying a user information count value that indicates the value of n, where f(.) is some predetermined function. For example, we can make f(n) = n or f(n) = n+1. In some embodiments, the maximum value (denoted as N) of the user information count field can indicate that at least f(N) user information fields exist before the Pre-FCS field. For example, the user information count field can be 4 bits, and a value of 15 can indicate that at least 16 user information fields exist before the Pre-FCS. In some embodiments, the location indication can indicate the number of bits in the MAC frame preceding the Pre-FCS field at a specific granularity level (e.g., octets).

[0167] In some embodiments, the location can be indicated by carrying the AID of the first of two adjacent user information fields carrying the Pre-FCS. In some embodiments, the Pre-FCS location indication may not be necessary if the AID corresponding to the Pre-FCS field or its location in the frame is predetermined. In some embodiments, a special encoded value for this field can indicate the absence of a Pre-FCS in the frame. In some embodiments, a separate field called "Pre-FCS Presence" may exist to indicate the presence of a Pre-FCS in the frame. Accordingly, a Pre-FCS count field may optionally exist when Pre-FCS Presence is set to 1. In some embodiments, instead of the Pre-FCS field, a message integrity check field or other similar security check can be added to the user information list.

[0168] Although the examples of Pre-FCS above illustrate their use and location in MU-RTS frames, they can also be included in other trigger frames, such as BAR, BQRP, and BSRP frames, as well as other trigger frames used as SBS IC frames.

[0169] While the examples above focus on DSO devices, as previously emphasized, these mechanisms also apply to other operating modes where an AP or non-APSTA can change its operating channel or bandwidth upon receiving a trigger frame, such as single-link EMLSR operation, DPS operation, NPCA operation, etc. Accordingly, such a trigger frame initiating a bandwidth switch may include the fields and features described above.

[0170] This document describes other non-AP STA behaviors according to this disclosure. In some embodiments, a UHR STA that has not performed any bandwidth switching or operational channel width changes can use the Pre-FCS value to perform early verification of the correctness of the trigger frame. Accordingly, it can choose to terminate the decoding process of the remainder of the trigger frame early. This may happen, for example, if the correctness check of the Pre-FCS fails. In another example, if a non-AP UHR STA is not expected to be addressed by the trigger frame (e.g., the sending address is from an unknown AP), it can terminate the decoding process of the trigger frame early even if the correctness check of the Pre-FCS passes. In some embodiments, PHY primitives can be used to instruct the PHY to terminate the reception process early. When the correctness check of the Pre-FCS passes, the non-AP STA can obtain a usable effective NAV duration. In some embodiments, in order to use the behavior described above, the non-AP STA may have to a priori instruct the AP that it chooses to terminate the decoding of the trigger frame, which includes the Pre-FCS, early. This instruction can be made during or after association, for example, by setting the capability bit to 1 or by sending a notification frame. In some embodiments, the sending STA may not carry any indication after the Pre-FCS field of the trigger frame, which is intended for use by UHR STAs or UHRSTAs that prematurely terminate the decoding process of the trigger frame.

[0171] Figure 14f A specific sequence indicating the end of the Pre-FCS field (or the beginning of the padding field) of a UHR STA is shown according to an embodiment. In some embodiments, the end of the Pre-FCS field may also be indicated by a specific bit sequence that indicates the start of padding from the perspective of an 802.11bn STA. Figure 14f An example of this design is depicted, where the Pre-FCS termination field can be a sequence of 2 octet bytes. After observing this particular sequence at the end of the Pre-FCS, the 802.11bn STA can treat the remaining bits of the trigger frame as reserved or padding bits. This mechanism could be used as a way to define new fields in trigger frames in future Wi-Fi generations that cannot be interpreted by the 802.11bn STA.

[0172] In some embodiments, the trigger frame for bandwidth switching may be sent in a non-HT repeating PPDU format, which may not include the NAV information in the PHY header. Accordingly, STAs from adjacent BSSs may need to decode the entire trigger frame to verify it and also verify the NAV value indicated in the frame, which may result in significant power waste, especially for longer trigger frames with a large amount of padding. Accordingly, in some embodiments, the trigger frame may carry a preliminary FCS value in a user information field with a predefined AID value and may exist earlier in the trigger frame. For example, the user information field with the preliminary FCS value may exist before any user information field addressing a non-AP STA associated with the AP. In some embodiments, the user information field may be the same as a special user information field carrying an extension of a common information field, or it may be an extension of a special user information field. The preliminary FCS value may be calculated based on the bits that appear before the preliminary FCS field. Non-AP UHR STAs not expected to be addressed by the trigger frame (e.g., sending addresses from unknown APs) may use the preliminary FCS value to prematurely terminate the decoding process of the trigger frame.

[0173] In some embodiments, in addition to the Pre-FCS / Intermediate FCS described above, the Pre-FCS may be a separate field carried in the trigger frame.

[0174] In some embodiments, if the length of the trigger frame exceeds a predetermined threshold, the UHR device sending the trigger frame may include at least one of a preliminary FCS or a Pre-FCS value within the trigger frame it sends. Where the presence of a preliminary FCS is optional within the UHR variant of the trigger frame, in some embodiments, a preliminary FCS presence bit may be present in a public information field (or a special user information field that extends public information), indicating whether the preliminary FCS field is present in the frame.

[0175] In some embodiments, where the NAV for sending TXOP has been indicated by transmission of different frames (e.g., RTS / CTS, etc.) before the transmission of the trigger frame, and the trigger frame does not update the TXOP duration, the initial FCS may not need to be carried in the trigger frame.

[0176] Figure 15 The hidden node problem in DSO operation according to an embodiment is illustrated. In some embodiments, a hidden node problem may exist in DSO operation. For example, consider a case where AP 1501 is outside the coverage area of ​​the adjacent Overlapping Basic Service Set (OBSS) AP 1503 and therefore the channel can be detected as idle. Therefore, AP 1501 may send an SBS IC to DSO STA 1505, requesting the STA to switch to the same subband as OBSS AP 1503, such as... Figure 15As described in [the document]. If the DSO STA 1505 directly sends a Complaint Transmission (CTS) after a subband handover, packet failure at adjacent APs may occur. In some embodiments, the DSO STA 1505 may need to switch to the indicated subband and perform energy detection and / or preamble detection on the new subband for a predetermined amount of time after the end of the SBS IC frame before sending the CTS frame. This predetermined amount of time may be the Short Interframe Spacing (SIFS) duration. The AP can indicate that the DSO STA needs to perform such an operation by setting the CS Requirement subfield of the Common Information field of the MU-RTS frame to 1. In some embodiments, when performing energy detection on the new subband after a subband handover, the energy detection threshold may also be reduced to a more conservative level, such as -72dBm or -82dBm. Similar mechanisms can also be used in response to other types of trigger frames, such as BSRP frames.

[0177] In some embodiments, the AP may not request a response to the SBS IC frame from a non-AP STA. After performing a subband handover, the AP may transmit a second MU-RTS frame or RTS frame before performing data transmission to request a response from the STA, thereby detecting hidden node problems.

[0178] In some embodiments, the SBS IC can be a trigger frame, and it can request responses from one or more DSO STAs and one or more non-DSO STAs. These STAs can be identified, for example, in the user information field of the SBS IC frame.

[0179] In some embodiments, when the SBS IC is a MU-RTS frame, it may be necessary to transmit the CTS response frame with a specific modulation and coding scheme (MCS) value and a specific PPDU format. In some embodiments, the CTS frame may be transmitted in a non-HT repeating PPDU format. In some embodiments, the format of the CTS response may differ for DSO and non-DSO STAs. For example, a non-DSO STA may respond with CTS in a non-HT repeating PPDU format, while a DSO STA may respond in a "modified" non-HT repeating PPDU format. Here, the modified non-HT repeating PPDU format may be similar to the non-HT repeating PPDU format, except that the transmission may occupy one or more non-primary channels without overlapping with the TXOP primary channel. The RU that sent the CTS response in the "modified" non-HT repeating PPDU format by the DSO STA may be indicated in the user information field of the SBS IC frame corresponding to the DSO STA. For example, this indication may be carried in the RU allocation subfield of the user information field. In some embodiments, it may not be necessary for all STAs addressed in the SBS IC frame to respond to the SBS IC frame. In some embodiments, if no CTS response to the MU-RTS is received on the primary 20MHz channel, the MU-RTS transmission can be considered to have failed. In some embodiments, if a successful CTS response is received on any 20MHz sub-channel of the TXOP bandwidth, the MU-RTS can be considered successful. In some embodiments, if no response to an SBS IC frame (e.g., CTS) is received on the primary 20MHz channel, the AP can transmit padding bits on the primary 20MHz channel for the duration of downlink frame transmissions performed on other 20MHz sub-bands where a successful response was received. Embodiments of this disclosure can also be applied to BSRP frames and their applicable response frames.

[0180] In some embodiments, where the SBS IC is a BSRP frame, the response frame can be a triggered PPDU (TB-PPDU) that includes a QoS empty frame carrying a Buffer Status Report (BSR). Additional steps may be taken to reduce the impact of inter-carrier interference (ICI) generated by the TB PPDU transmitted by the DSO STA. In some embodiments, it may be necessary to transmit the TB PPDU in a specific MCS and / or a specific PPDU format. As with a regular BSRP response, the TB PPDU transmitted by the DSO STA may be transmitted on the resource element indicated in the RU allocation subfield of the user information field corresponding to the DSO STA. In some embodiments, aggregation of data frames within the TB PPDU may not be permitted. In some embodiments, the TB PPDU may be limited in terms of its maximum duration. In some embodiments, the number of empty subcarriers at the end of the RU allocated by the DSO STA for the TB PPDU may be increased to reduce inter-carrier interference. In some embodiments, the response frame may also be a multi-STA block ACK frame. This may be, for example, if the SBS IC requests the use of such a response frame and / or if the responding STA intends to send additional information about its unavailability, the required resources for transmitting buffered data, and other operations.

[0181] This document describes power pre-correction for enabling response frames according to this disclosure. In some embodiments, where the SBS IC is a MU-RTS frame, the response frame for responding to the STA may be transmitted at the maximum permissible power for responding to the STA (subject to other rules or constraints).

[0182] In some embodiments, where the SBS IC is a BSRP frame, if this is indicated in the UL target receive power subfield of the SBS IC frame, it may be necessary to utilize power pre-correction when transmitting the response frame. A typical non-DSO STA calculates the transmit power of the response as follows: ,in This is the path loss calculated based on the received SBS IC. In the case of DSO STA, since the response can be transmitted on a subband different from the subband where the SBS was received, DSO STA may... The correct value for the transmit power used to determine the response TB PPDU cannot be known. To address this issue, in some embodiments, the UL target receive power subfield of the SBS IC frame can be set to 127, allowing the STA to use its maximum allowed transmit power. In some embodiments, a mapping function can be proposed to map the path loss measured by the DSO STA on the primary 20MHz channel to the expected path loss of the DSO STA on the new subband after subband switching. This mapping can be, for example, a conservative estimate given by Equation 1:

[0183]

Mathematical Formula 1

[0184]

[0185] in It is to estimate the expected path loss on the new subband. This is the path loss estimated on the primary 20MHz channel, and P is a predetermined constant, such as 3dB or 0dB. Accordingly, the DSO STA can use this value. To calculate the allowable transmit power of a TB PPDU .

[0186] In some embodiments, after a subband handover, the DSO STA can use the remainder of the SBS IC frame (such as remaining OFDM symbols) to acquire DL received signal power measurements. To do this, the DSO STA can instruct a DSO padding delay value that is long enough to allow it to receive the necessary OFDM symbols of the SBS IC frame after the DSO subband handover. In some embodiments, a known signal of a given power level can be transmitted for at least a portion of the remaining frame (e.g., at a predetermined OFDM symbol location). The DSO STA can then use this known signal to acquire or refine the received signal power measurements, and accordingly acquire or refine the path loss on the allocated subband. Then, the DSO STA can use this value to determine the transmission power of the response. .

[0187] This document describes the time synchronization of enabling response frames according to this disclosure.

[0188] Figure 16 A PPDU carrying an SBS IC frame and its PHY preamble including an L-SIG field is shown according to an embodiment. The non-HT PPDU includes a preamble and a data portion. The preamble includes a conventional short training field (L-STF), a conventional long training field (L-LTF), and a conventional signal field (L-SIG). The data portion includes a service field, a PSDU field, a 6-tail bit field, and a padding bit field.

[0189] The L-STF field is the first field of the old OFDM PLCP preorder code and can be used for group detection and coarse frequency offset.

[0190] The L-LTF field is the second field of the preamble and can be used for timing synchronization and fine frequency offset.

[0191] The L-SIG field includes an OFDM symbol whose duration varies with the channel bandwidth. L-SIG can include packet information specific to the received configuration. Bits 0 through 3 can specify the data rate (modulation and coding rate) for non-HT formats. Bit 4 can be reserved for future use. Bits 5 through 16: for non-HT formats, specify the data length (the amount of data sent in octets); for HT mixed formats, specify the transmission time; for VHT formats, specify the transmission time. Bit 17 has an even parity check for bits 0 through 16. Bits 18 through 23 contain all zeros in the tail bit.

[0192] The service field can include 16 zeros to initialize the data scrambler.

[0193] The PSDU field can be a variable-length field that includes Physical Layer Convergence Protocol (PLCP) Service Data Units (PSDUs).

[0194] A six-bit tail field may be needed to terminate the convolutional code. This field uses six zeros for a single encoded stream.

[0195] The padding bit field can be a variable-length field required to ensure that non-HT data fields include an integer number of symbols.

[0196] In some embodiments, the SBS IC frame can be a trigger frame. Upon receiving the trigger frame, the STA, in response to sending an HETB PPDU, a non-HT PPDU, or a non-HT repeating PPDU, can ensure that the transmission start time of the HETB PPDU, non-HT PPDU, or non-HT repeating PPDU is within ±0.4μs + 16μs at the STA's transmit antenna connector from the end of the last OFDM symbol of the trigger PPDU (if it does not contain a PE field) or the PE field of the trigger PPDU (if a PE field exists). In DSO operation, because the DSO device stops decoding the SBS IC frame and switches to a new channel (where it does not have channel estimation) before filling the field, it may not be able to continue receiving the remainder of the trigger frame to identify the end of the frame. Accordingly, in some embodiments, the DSO STA can use the L-SIG field of the PPDU that includes the SBS IC (e.g., ...). Figure 16The duration of the PPDU (Programmable Component Distribution Unit) is determined and a countdown timer for that duration is started. In some embodiments, before setting the countdown timer, the DSO STA may modify the duration value to account for the symbol timing offset of the transmitting device, which can be estimated based on the parameters of the SBS IC. The expiration time of the timer can be used as an indication of the end of the trigger frame PPDU, and the STA can respond with a CTS on the new channel for a fixed duration (e.g., SIFS time or 16 μs time) after the expiration time. In some embodiments, the common information field of the MU-RTS frame may include a new “Response Time” subfield indicating the exact time (counting from the start of the PPDU containing the MU-RTS frame) when a response CTS should be sent.

[0197] In some embodiments, after a subband switch, the DSO STA can use the remainder of the SBS IC frame (such as remaining OFDM symbols) to acquire or refine OFDM symbol timing. A known signal can be transmitted during at least a portion of the remaining frame (e.g., at a predetermined OFDM symbol location). The DSO STA can then use this known signal to acquire or refine the symbol timing.

[0198] This document describes frequency synchronization of response frames according to this disclosure. In some embodiments, the SBS IC frame may be a trigger frame. In some embodiments, after receiving a trigger frame, with the TXVECTOR parameter TRIGGER_RESPONING set to true, when transmitting the following types of PPDUs: HE TB PPDUs, and non-HT or non-HT repetitive PPDUs, STA compensation may be required for carrier frequency offset (CFO) errors and symbol clock errors with respect to the corresponding trigger PPDU. After frequency compensation, when measured at 10% of the complementary cumulative distribution function (CCDF) of the CFO error in the AWGN at a received power of -60 dBm in the primary 20 MHz, the absolute value of the residual CFO error relative to the corresponding trigger PPDU may not exceed the following levels:

[0199] 350Hz for the data subcarrier used in HE TB PPDU (this can be applied to BSRP frames or other non-MU-RTS triggered frames);

[0200] For non-HT PPDUs or non-HT repeating PPDUs, the kHz setting is 2 (this can be applied to MU-RTS frames).

[0201] For DSO equipment, subband switching involves a change in the oscillator frequency, which may cause a change in the CFO value of the DSO equipment. Therefore, any CFO compensation factor calculated from the received SBS IC frame before the subband switching may no longer be applicable after the subband switching. If the DSO STA sends a response frame directly to the SBS IC frame based on this incorrect CFO compensation factor, it may result in a violation of the foregoing requirements and cause significant inter-carrier interference.

[0202] Accordingly, in some embodiments, the BSRP frame may not be used as the SBS initial control frame for the DSO device because its CFO requirement may be too stringent (350Hz). The MU-RTS frame can be used as the SBS IC because its requirement is less stringent (2kHz). In some embodiments, when the trigger frame requests a response from the DSO device, the CFO error requirement for the UHR device in response to the BSRP can be reduced to allow for a higher CFO value. In some embodiments, additional constraints can be imposed on the TBPPDU sent by the DSO STA in response to the BSRP frame to allow for a reduced CFO error requirement. For example, some embodiments may have one or more of the following constraints on the response frame.

[0203] In some embodiments, the RU size allocated to the DSO STA in the BSRP can be greater than the minimum value, such as 20 MHz or 242 frequency modulations.

[0204] In some embodiments, in the RU allocated to the DSO STA, the DSO STA may need to use additional empty subcarriers (and then those used by non-DSO STAs) during the transmission of response frames.

[0205] In some embodiments, in the RU allocated to the DSO STA, additional pilot subcarriers may need to be used by the DSOSTA during the transmission of the response frame (and then by those used by the non-DSO STA). In some embodiments, there may be constraints on the maximum length / duration of the response frame.

[0206] In some embodiments, it may be necessary for all or some STAs to send response frames with a lower (and therefore more robust) MCS value and / or in a specific PPDU format. STAs may include, for example, DSO STAs or non-DSO STAs, which are assigned to RUs adjacent to the DSO STAs in the BSRP frame. In some embodiments, it may be disallowed for response frames to contain aggregations of data frames.

[0207] In some embodiments, certain implementations of the DSO device may be able to perform accurate CFO compensation to transmit the response to the BSRP frame as an SBS IC frame, while other implementations may not be able to do so. Accordingly, in some embodiments, the DSO device may indicate in its UHR capability element (which it transmits in probe request and associated response frames, etc.) whether it is able to receive the BSRP frame as an SBS initial control frame, as according to embodiments. Figure 17a As shown.

[0208] Figure 17a An example is shown illustrating whether a DSO device according to an embodiment can receive BSRP as an indication of SBSIC in a UHR capability element. The frame includes an element ID field, a length field, an element ID extension field, a UHR MAC capability information field, and a UHR PHY capability information field. The UHR MAC capability information field includes a DSO support field, a maximum channel handover time field, a BSRP capability field for DSO, and a reserved field.

[0209] The element ID provides an identifier for the element. The length field provides the length information of the element. The element ID extension field provides extended information about the element. The UHR MAC capability information field provides capability information for the element and may include several subfields as described below.

[0210] The DSO support field provides information about whether DSO is supported. The maximum channel handover time field provides information about the maximum channel handover time the AP is willing to accommodate for any STA intending to operate in DSO mode. In some embodiments, the AP may also indicate in its UHR capability the maximum channel handover time it is willing to accommodate for any STA intending to operate in DSO mode. In some embodiments, the maximum allowed channel handover time for DSO may be predetermined by a standard, so this field may not exist. Reserved fields may be reserved.

[0211] The BSRP bit field for DSO capability provides an indication of whether the DSO device can receive BSRPs as SBSIC frames. It is set to 1 to indicate that the DSO device can receive BSRP frames as SBSIC frames, and otherwise set to 0. In some embodiments, the capability to receive BSRPs can be different for each STA of the MLD, and therefore the BSRP for the DSO capability field can be different for each STA. This can be indicated by using a BSRP bitmap capable of being used for DSO, or by including a BSRP field capable of being used for DSO in the STA profile of each basic multilink element sent by the MLD. In some embodiments, the DSO device may provide this indication in the DSO notification frame it sends to switch to DSO operation mode.

[0212] Figure 17b A DSO notification frame according to an embodiment is shown, which includes an indication of whether the DSO device can receive BSRP as an SBS IC frame. In some embodiments, the DSO STA may be able to meet the CFO requirements in response to BSRP SBS IC frames for a specific type of subband handover. A limitation may be, for example, that the difference in center frequencies between the two channels (before and after the handover) should be below a given threshold. This threshold may be indicated by the DSO STA in its UHR capability element or in the DSO notification frame. In some embodiments, the DSO STA may pre-negotiate with the AP to select a set of M subband handovers, and it may be able to perform CFO correction on the set of M subband handovers and meet the CFO requirements in response to BSRP SBS IC frames.

[0213] Specifically, Figure 17b A DSO mode notification frame according to an embodiment is shown. The frame may include a category field, a protected UHR action field, a dialogue token field, and a DSO control field. The category field provides category information for the frame. The protected Ultra-High Reliability (UHR) action field provides UHR action information. The dialogue token field provides token information for the frame. The DSO control field provides DSO control information and includes several subfields as described below.

[0214] DSO control fields may include DSO mode field, link bitmap field, channel switching timing field, supported channel field, supported channel width field, BSRP capability field for DSO, reserved field, and DSO MCS and NSS set field.

[0215] The DSO mode field provides an indication of whether the sending STA is switching to or out of DSO mode. In one example, this can be indicated using a 1-bit DSO mode field.

[0216] A link bitmap can provide an indication of non-AP STAs attached to non-AP MLDs to which DSO mode switching applies. In some embodiments, this can be indicated using a 16-bit link ID bitmap field. In some embodiments, it can be indicated using a 4-bit link ID field.

[0217] The channel handover timing field can provide an indication of the time a non-AP STA / MLD STA needs to perform a channel handover upon receiving an allocation. In some embodiments, this can be a two-octet field indicating the time in microseconds. In some embodiments, this indication can be carried in the channel handover timing field of the channel handover timing element.

[0218] The supported channel field can provide an indication of the supported sub-channels that a non-AP STA / MLD can switch to. In some embodiments, this can be indicated in a 16-bit channel bitmap, where each bit corresponds to a 20MHz channel starting from the lowest such 20MHz channel within the maximum BSS bandwidth. In some embodiments, this can be indicated in the supported channel element. An indication of the bandwidth of the transmission that a non-AP STA / MLD can support. In some embodiments, this can be indicated using a 4-bit field if the STA / MLD supports 20×2 in DSO mode. n The maximum bandwidth in MHz is indicated by n. In some embodiments, this can be indicated in the supported channel width set field and the extended NSS BW support field.

[0219] The DSO support and MCS and NSS set fields can provide an indication of the MCS-NSS sets that a non-AP MLD / STA can support after a handover. In some embodiments, this can be indicated in the supported UHR-MCS and NSS set fields.

[0220] In some embodiments, to estimate the CFO value after performing a subband handover, the DSO STA may use some of the received OFDM symbols of the SBS IC frame after the subband handover. To do this, the DSO STA may instruct a DSO padding delay value that is long enough to allow it to receive the necessary OFDM symbols of the SBS IC frame after the DSO subband handover. In some embodiments, during the reception of these OFDM symbols, the DSO STA may track pilot subcarriers to estimate the residual CFO value for correction. In some embodiments, one or two pilot symbols (e.g., similar to an LTF field) may be introduced into the SBS IC frame via puncturing between the I-FCS field and the FCS field to aid CFO estimation. The location of these symbols can be chosen such that all DSO STAs can perform a channel handover before encountering these symbols. In some embodiments, these OFDM symbols may be the same symbols, and a relative phase rotation between two identical OFDM symbols may be used for CFO estimation, similar to the process used for estimation from a long training field (LTF). In some embodiments, OFDM symbols from the forward error correction (FEC) padding or packet extension field can be used to perform residual CFO estimation. The length of the packet extension field can be, for example, 8 μs or 16 μs. In some embodiments, the AP can indicate the presence of such a CFO-tracking OFDM symbol within the frame in the common information field of the SBS IC frame (or in a special user information field carrying additional common information). In some embodiments, the presence indication for the CFO-tracking OFDM symbol and the Pre-FCS field can both be common. A non-AP DSOSTA, when enabling DSO operation, can indicate to the AP whether it requires such a CFO-tracking OFDM symbol at the end of the SBS IC frame. This requirement can be for all SBS IC frames or for a specific SBS IC frame, such as a BSRP frame, etc.

[0221] In some embodiments, after a subband handover, the DSO STA can use the remainder of the SBS IC frame (such as remaining OFDM symbols) to acquire or refine the CFO estimate. A known signal can be transmitted during at least a portion of the remaining frame (e.g., at a predetermined OFDM symbol location). The DSO STA can then use this known signal to refine the residual CFO estimate after performing the handover.

[0222] Although the description of BSRP frames as SBS IC frames is based on several embodiments of this disclosure, the limitations, instructions, and procedures described may also be applied to any other new frames introduced as SBS IC frames.

[0223] This document describes an SBS IC frame cancellation indication according to the present disclosure. In some embodiments, after sending an SBS IC frame indicating a subband switch to the DSO STA, the AP may determine that it needs to end a transmission opportunity (TXOP). This may occur, for example, if no response to the SBS IC frame is received on the primary 20MHz channel, or if the AP determines that it has some other higher priority task to complete, among other factors.

[0224] In some embodiments, the AP may not need to provide the same notification to the STA addressing in the SBS IC frame when making such a decision to relinquish the TXOP. In some embodiments, if a DSO STA addressing in the SBS IC frame and performing a subband handover does not receive any frames addressed to it within a certain threshold duration, the DSO STA may switch back to the main channel. In some embodiments, if the DSO STA observes a preamble with a BSS color that matches its own AP's BSS color but has a different destination address, and if the AP has indicated that the DSO STA can be served later within the TXOP, the DSO STA may wait for a longer threshold duration before switching back to the main channel.

[0225] In some embodiments, when making such a decision to abandon a TXOP, the AP may send a frame indicating the end of the TXOP. In some embodiments, the frame may be sent in a non-HT repeating PPDU format. In some embodiments, the frame may be a CF-end frame. In some embodiments, the frame may be a new frame, such as a new action frame. In some embodiments, the frame may also carry an indication of a subset of DSO STAs that may not be served within the TXOP and can switch back to the primary channel.

[0226] This document describes enabling joint operation in EMLSR / EMLMR mode and DSO mode according to this disclosure. In some embodiments, the device may not operate in EMLSR / EMLMR mode and DSO mode simultaneously. In some embodiments, the device may be able to operate in both EMLSR / EMLMR mode and DSO mode simultaneously. In some embodiments, such a device may declare two padding delays in its UHR capability element, including one for DSO channel handover and one for EMLSR / EMLMR link handover delay. In some embodiments, the device may report a single value applicable to all switches.

[0227] Figure 18The EML control field, as an optional subfield of a DSO notification frame according to an embodiment, is illustrated. In some embodiments, the EML control field may be an optional subfield of the DSO notification frame, as shown in the embodiment, for simultaneous switching between DSO mode and EMLSR mode or DSO mode and EMLMR mode. Figure 18 As shown. The presence of the EML control field in the DSO notification frame can be indicated in the "Include EML Control" bit of the DSO control field. In some embodiments, a DSO notification frame and an EML mode frame can be sent separately to switch to EMLSR / EMLMR mode and DSO mode, respectively. In some embodiments, the DSO link can be the same as the EMLSR / EMLMR link. In some embodiments, link bitmaps can be indicated separately for DSO and EMLSR / EMLMR operations.

[0228] In some embodiments, if the DSO fill delay and the EMLSR / EMLMR fill delay are different values, the AP may apply the larger of the two delays when a non-AP STA, which is recommended to operate on both the EMLSR / EMLMR link and the DSO link, switches to a non-primary channel. If the link is an EMLSR / EMLMR link and not a DSO link, the EMLSR / EMLMR fill delay may be applied. If the link is a DSO link but not an EMLSR / EMLMR link, the DSO fill delay may be applied when switching to another sub-channel.

[0229] In some embodiments, when the device operates jointly in DSO mode and EMLSR / EMLMR mode, any rules applicable to EMLSR / EMLMR operation can be applied, such as group addressing frame buffering, not transmitting ICFs on other links during frame exchange with EMLSR on the first link, or during the limited target wake-up time (rTWT) service period (SP) on the first link. In some embodiments, the ability to use BSRP as SBS IC frames is implicitly applicable to these types of devices. In some embodiments, it can be as follows: Figure 17a and Figure 17b The capability is explicitly indicated as shown.

[0230] Figure 19 A flowchart illustrating an example procedure performed by an AP to send an SBS IC frame to initiate a subband handover operation for a DSO device is shown. Although one or more operations are described or shown in a specific order, in other embodiments, the operations may be rearranged in a different order, which may include performing multiple operations in at least partially overlapping time periods. Figure 19 The flowchart depicted in the diagram illustrates the process in AP (such as...) Figure 3 The operations performed in the AP shown in the figure.

[0231] In Operation 1901, upon winning a TXOP, the AP determines the appropriate subchannel allocation to the STA based on its DSO parameters. In some embodiments, the AP may send a CTS to itself in a non-HT repeated PPDU format to protect all subchannels it has already won channel access to.

[0232] In Operation 1903, the AP determines the appropriate SBS IC based on the STA capability. In some embodiments, a MU-RTS frame or a BSRP frame can be used as the SBS IC frame for the DSO device. In some embodiments, the public information field may have a DSO include field or a subtype field to indicate that the MU-RTS or BSRP frame is an SBS IC frame. In some embodiments, reserved fields in the user information field can be used to indicate DSO parameters in the DSO-specific user information field.

[0233] In operation 1905, the AP calculates (if applicable) the Pre-FCS and other DSO parameters to be included. In some embodiments, the parameters may be scheduling time fields to indicate whether the AP intends to perform frame exchange with the indicated STA immediately or later within the TXOP. In some embodiments, the AP may include the Pre-FCS field in the user information list of the MU-RTS or BSRP frame, which can be used by the DSO device to perform frame verification. Since the user information list arrives before filling, the DSO device can use the Pre-FCS verification field to perform frame verification and then perform subband switching during filling.

[0234] In operation 1907, the AP sends an SBS IC frame to the STA with appropriate padding. In some embodiments, the medium-retaining transmission over the medium may be the padding field of a MU-RTS or BSRP frame.

[0235] In Operation 1909, the AP determines whether an SBS IC frame transmission was successful based on the response to the SBS IC frame. In some embodiments, if no response to the SBS IC frame is received on the primary 20 MHz sub-channel, the SBS IC frame transmission may be considered a failure. In some embodiments, if a successful response is received on any 20 MHz sub-channel of the TXOP bandwidth, the SBS IC frame may be considered successful. In some embodiments, if no response is received on the primary 20 MHz channel, the AP may transmit padding bits on the primary 20 MHz channel for the duration of downlink frame transmissions performed on other 20 MHz sub-bands where a successful response was received.

[0236] In Operation 1911, the AP determines that the TXOP is to be cancelled and provides notification (if applicable). In some embodiments, when making such a decision to relinquish the TXOP, the AP may not provide the same notification to the STAs addressed in the SBS IC. In some embodiments, when making such a decision to relinquish the TXOP, the AP may send a frame indicating the end of the TXOP. In some embodiments, the frame may be sent in a non-HT repeating PPDU format. For example, the frame may be a CF end frame. In some embodiments, the frame may be a new frame, such as a new action frame. In some embodiments, the frame may also carry an indication of a subset of DSO STAs that may not be served within the TXOP and can switch back to the primary channel.

[0237] Figure 20 A flowchart illustrating an example procedure for transmitting a corresponding response, performed by a non-AP STA upon receiving an SBS IC frame, according to an embodiment, is shown. Although one or more operations are described or shown in a specific order, in other embodiments, the operations may be rearranged in a different order, which may include performing multiple operations in at least partially overlapping time periods. Figure 20 The flowchart depicted in the diagram illustrates the situation in non-AP STA (such as...) Figure 3 The operations performed in the non-AP STA shown.

[0238] In Operation 2001, the STA provides an indication of the types of SBS ICs that can be received.

[0239] In Operation 2003, upon receiving an SBS IC from the AP, the STA verifies whether a DSO-specific user information field is included for use by the STA. In some embodiments, the trigger frame can be used as an SBS IC frame for the DSO device. In some embodiments, the common information field can have a DSO inclusion field or a subtype field to indicate that the trigger frame is an SBS IC frame. In some embodiments, reserved fields of the user information field can be used to indicate DSO parameters in the DSO-specific user information field.

[0240] In Operation 2005, if applicable, the STA performs FCS verification using the Pre-FCS field, and if the FCS verification passes, switches to the requested subband in the SBS IC. In some embodiments, the AP may include the Pre-FCS field in the user information list of the trigger frame, which can be used by the STA to perform frame verification. Since the user information list arrives before being populated, the STA can use the Pre-FCS verification field to perform frame verification and then perform subband switching during the population period.

[0241] In Operation 2007, the STA initiates channel sensing on the new channel at the determined end-of-frame time.

[0242] In Operation 2009, the STA determines a power pre-correction for the SBS IC response frame. In some embodiments, to help the DSO STA determine the TX power, the UL target received power subfield of the SBS IC frame can be set to 127, allowing the STA to use its maximum allowed transmit power. In some embodiments, a mapping function can be proposed to map the path loss measured by the DSO STA on the primary 20MHz channel to the expected path loss of the DSO STA on the new subband after subband handover. In some embodiments, the STA can use the remainder of the SBS IC frame (such as remaining OFDM symbols) after subband handover to acquire DL received signal power measurements. To do this, the STA can instruct a DSO padding delay value that is long enough to allow it to receive the necessary OFDM symbols of the SBS IC frame after performing the DSO subband handover. In some embodiments, a known signal with a given power level can be transmitted during at least a portion of the remaining frame (e.g., at a predetermined OFDM symbol location). The STA can then use this known signal to acquire or refine the received signal power measurement on the assigned subband, and can then use this value to determine the transmit power of the response.

[0243] In operation 2011, the STA performs CFO compensation applicable to the SBS IC. In some embodiments, in order to estimate the CFO value after performing a subband handover, the STA may use some of the received OFDM symbols of the SBS IC frame after performing the subband handover. To do this, the STA may instruct a DSO padding delay value that is long enough to enable it to receive the necessary OFDM symbols of the SBS IC frame after performing the DSO subband handover.

[0244] In Operation 2013, if the channel is determined to be idle within SIFS, the STA transmits a response frame to the SBS IC frame with appropriate power and CFO correction (if applicable), and follows any additional rules (if applicable).

[0245] In Operation 2015, if the TXOP is notified of its end or no frame exchange is initiated within a threshold time, the STA switches back to the primary channel (if applicable).

[0246] This document describes determining SBS compliance prior to data transmission according to this disclosure. In some embodiments, DSOSTA compliance with the AP's request to perform a subband handover within the TXOP may be optional. Accordingly, at the start of the TXOP, the AP may aim to identify which STAs are willing to comply with the subband handover request. To this end, the AP may send a trigger frame to all STAs it intends to serve within the TXOP. This trigger frame may be, for example, a variant of a Buffer Status Report Polling (BSRP) frame, a variant of a Multi-User Request Transmit (MU-RTS) frame, or a new variant of the trigger frame. By using the response to this trigger frame, during the SIFS duration following the trigger frame, the STA can indicate whether it will comply with the AP's request to perform a subband handover within the TXOP. In some embodiments, if the trigger frame is a BSRP frame, a new format for the user information field may be defined, which may be applicable to STAs operating in DSO mode. Similarly, in some embodiments, the response to the BSRP trigger frame may be different if sent by an STA operating in DSO mode. In addition to (or instead of) carrying buffer status report information, the response may carry an explicit indication of whether the DSO STA is willing to comply with the subband switching request.

[0247] In some embodiments, to ensure the protection of the TXOP bandwidth during trigger response, the AP may attempt to ensure that response frames from STAs collectively occupy the entire TXOP bandwidth with a high probability. To this end, in the trigger frame, the AP may assign different RUs across the TXOP bandwidth to different STAs for transmitting the trigger response, as indicated in the RU allocation field corresponding to the user information fields of those STAs. If the STA is operating in DSO mode, its RU allocation may be outside its current operating bandwidth, and accordingly, it can be expected that the STA will perform a subband handover operation before transmitting the trigger response frame (if it decides to comply with the AP's request). The AP may ensure that sufficient padding is provided in the trigger frame to ensure that all such STAs that need to perform a subband handover before transmitting the trigger response can do so before the end of the trigger frame. In some embodiments, the RUs assigned to DSO STAs in the trigger frame used for response may be distributed RUs, i.e., the subcarriers assigned to the STAs may have a large inter-subcarrier frequency spacing. This may be to ensure that the entire TXOP bandwidth is still protected even if some STAs do not respond to the trigger frame.

[0248] In some embodiments, the trigger response may be expected to be below a certain MCS or rate and transmitted in a specific frame format. A mechanism may also exist to determine the applicable transmit power for the response frame. In some embodiments, the CFO requirement for the trigger response may be reduced. In some embodiments, aggregation of data in the response may be prohibited and / or the duration of the trigger response may be constrained. The AP may indicate the duration of the trigger response in the common information field of the trigger frame, and the response STA may use padding to ensure that the response occupies the medium until the expected duration of the trigger response.

[0249] In some embodiments, the actual RUs (RUs) allocated later in the TXOP to a STA in DSO mode for data transmission (downlink or triggered uplink) may differ from the RUs allocated to it for sending trigger response frames. In some embodiments, a predetermined mapping may exist between the RUs allocated to the DSO STA for trigger response and the subbands that the DSO STA is expected to listen to for operations such as data transmission. Therefore, based on the RU allocation field of the trigger frame indicating the RUs used for trigger response, DSOTA can determine which subbands it should listen to for data transmission / reception, etc. For example, each RU allocated for trigger response may be associated with a specific 20 / 40 / 80 / 160MHz channel as part of it. Accordingly, a DSO STA with an X MHz operating bandwidth may be expected to listen to an X MHz channel, and the RUs allocated to it for trigger response are part of that X MHz channel. In some embodiments, there may be explicit and separate indications of the subbands that the DSO STA is expected to listen to, and these may be allocated to RUs for data transmission later in the TXOP. This indication may be carried in the subband allocation subfield of the DSOTA's user information field, addressed in the trigger frame sent by the AP. In some embodiments, subband allocation may be a superset of the RU allocation allocated to the DSO STA for triggering a response, unless an exception is described herein. In some embodiments, explicit indication may be optional, i.e., the subband allocation field may optionally exist in the user information field, as indicated by the subband allocation presence bit in the user information field. If the subband allocation field is not present in the DSO STA's user information field, the STA may determine the subband it will listen to based on a predetermined mapping. If the subband allocation subfield exists in the DSO STA's user information field, the device may use that field to determine the subband to listen to. In some embodiments, the AP may indicate the maximum size of resource units it intends to allocate to the DSO STA for data transmission. When this indication is received in the user information field addressed to the DSO STA, the DSO STA may determine the subband to listen to based on the indication and a predetermined mapping between RU allocation and listening bandwidth.

[0250] Figure 21The user information field of the SBS IC according to an embodiment is shown, which provides separate indications of the trigger response RU and the subband to be monitored. For example, in the case of a BSRP frame, the subband allocation field can borrow the same field bits as the conventional SS allocation / RA-RU information field.

[0251] In some embodiments, based on the trigger response received from the triggered STA, the AP can determine which STAs are capable of receiving on different subbands within the TXOP. Therefore, it can perform RU notification allocation within the TXOP for data transmission, etc.

[0252] Figure 22The user information field of an SBS IC frame according to an embodiment is shown, which provides an indication of subband pre-allocation to indicate that a delayed subband handover is required after sending a trigger response. In some embodiments, the AP may determine that some DSO devices may require a long time to switch to a new subband and / or may not be able to meet the transmission power or carrier frequency offset requirements associated with the trigger response frame if the device needs to transmit a response after the subband handover. In some embodiments, for such DSO devices, the AP may provide RU allocation for trigger response within its current operating bandwidth itself, and may carry a separate indication of the subbands they expect to listen on in the remaining TXOP for data transmission, etc. The subband indication may be carried in the subband allocation subfield of the user information field of those DSO STAs addressing the trigger frame sent by the AP. In some embodiments, the subband allocated by the subband allocation subfield may be allocated in the RU allocation field to a STA other than the RU used for trigger response. If the RU allocated to the DSO STA for trigger response is within its current operating bandwidth, and the allocated subbands for listening are not a subset of its current operating bandwidth, the DSO STA may be expected to perform a subband handover after sending a response to the trigger frame. In some embodiments, it may be implied that the AP may not immediately serve the DSO STA after receiving a trigger response frame. In some embodiments, the operation may be similar, but a separate bit may be present in the user information field of the DSO STA addressed to the trigger frame sent by the AP to explicitly indicate to the STA that a response to the trigger frame is expected before performing a subband handover, and the AP will not immediately serve the STA after the trigger response. This bit may be referred to, for example, as a DSO pre-allocation field or a DSO delayed allocation field. In some embodiments, such a DSO device may not be required to send a response to the trigger frame, and the AP may not immediately serve the DSO STA within the TXOP. The AP may use the DSO pre-allocation subfield of the user information field of the STA addressed to the trigger frame to provide an indication that the DSO STA does not need to respond to the trigger frame. The AP may use the RU allocation subfield of the user information field of the STA addressed to the trigger frame to indicate the subband that the DSO STA is expected to listen to.

[0253] Embodiments of this disclosure allow the use of existing trigger frames for DSO operation, including providing a mechanism for the DSO device to perform FCS verification on the SBS IC frame before the start of the padding field of the SBS IC frame. Therefore, embodiments of this disclosure provide a mechanism that enables the DSO device to verify the correctness of the SBS IC frame (via a frame verification sequence) before performing a subband handover operation. Embodiments of this disclosure also provide a mechanism that allows an EMLSR device to operate in DSO mode.

[0254] According to an example embodiment, an access point (AP) in a wireless network may include: a memory; and a processor coupled to the memory. The processor is configured to: generate a trigger frame requesting a response from one or more stations (STAs) and including information for a dynamic subband handover operation, wherein the trigger frame includes a common information field and one or more user information fields, the common information field providing information shared by the one or more STAs, and each user information field providing information specific to a particular STA among the one or more STAs; send the trigger frame to the one or more STAs to request the dynamic subband handover operation; and determine, based on whether a response to the trigger frame is received from the one or more STAs, whether the dynamic subband handover operation was successfully performed at the one or more STAs.

[0255] According to an example embodiment, the public information field includes a trigger frame that triggers a dynamic subband handover operation for at least one or more STAs, and one or more user information fields include an indication of information associated with the dynamic subband handover operation.

[0256] According to an example embodiment, one or more user information fields are addressed to the Dynamic Subband Operation (STA) and include information associated with the Dynamic Subband Switching Operation.

[0257] According to the example embodiment, the triggering frame is a Multi-User Request Transmit (MU-RTS) frame, a Block Acknowledgment Request (BAR) frame, or a Buffer Status Report Polling (BSRP) frame.

[0258] According to an example embodiment, the processor is also configured to: determine that no frame in response to the trigger frame has been received on the main channel; and determine that the trigger operation has failed at one or more STAs.

[0259] According to an example embodiment, the processor is also configured to: receive a frame in response to a trigger frame from at least one of one or more STAs on any subchannel of a transmission opportunity (TXOP); determine that a subband switching operation was successful at at least one of one or more STAs; and initiate a transmission to at least one of one or more STAs while also signaling to occupy the medium on the main channel.

[0260] According to an example embodiment, the trigger frame includes a field that includes information used by one or more STAs to determine the transmit power in order to send a response.

[0261] According to an example embodiment, the effect of the residual carrier frequency offset between the trigger frame and the expected response of a specific dynamic subband operation STA is mitigated by one or more of the following: limiting the transmission parameters of the response frame, including modulation and coding schemes or response transmission duration; and including a field in the trigger frame that includes information used by the specific dynamic subband operation STA to determine the residual carrier frequency offset after performing a channel switch to the indicated subband.

[0262] According to an example embodiment, the resource allocation to one or more dynamic subband STAs indicated in the trigger frame comes from a set of subbands negotiated between the AP and one or more dynamic subband STAs.

[0263] According to the example embodiment, the trigger frame indicates whether one or more STAs need to perform energy detection or preamble detection on a new subchannel within a certain amount of time after the end of the trigger frame before transmitting a response.

[0264] According to an example embodiment, a station (STA) in a wireless network includes: a memory; and a processor coupled to the memory. The processor is configured to: receive from an access point (AP) a trigger frame requesting a dynamic subband handover operation, wherein the trigger frame includes a common information field and one or more user information fields, the common information field providing information common to one or more STAs, and each user information field providing information specific to a particular STA among the one or more STAs; perform the dynamic subband handover operation requested in the trigger frame; and send a transmission permission response frame to the AP in response to the trigger frame.

[0265] According to an example embodiment, the public information field includes a trigger frame that triggers a dynamic subband handover operation for at least one or more STAs, and one or more user information fields include an indication of information associated with the dynamic subband handover operation.

[0266] According to the example embodiment, the triggering frame is a Multi-User Request Transmit (MU-RTS) frame, a Block Acknowledgment Request (BAR) frame, or a Buffer Status Report Polling (BSRP) frame.

[0267] According to an example embodiment, a computer-implemented method for wireless communication at an access point (AP) in a wireless network is disclosed. The method may include: generating a trigger frame that requests a response from one or more stations (STAs) and includes information for a dynamic subband handover operation, wherein the trigger frame includes a common information field and one or more user information fields, the common information field providing information common to the one or more STAs, and each user information field providing information specific to a particular STA among the one or more STAs; sending the trigger frame to the one or more STAs to request the dynamic subband handover operation; and determining whether the dynamic subband handover operation was successfully performed at the one or more STAs based on whether a response to the trigger frame was received from the one or more STAs.

[0268] Unless otherwise specified, references to elements in the singular form are not intended to indicate one and only one, but rather one or more. For example, a “one” module can refer to one or more modules. In the absence of further constraints, elements preceded by “a,” “an,” “the,” or “the” do not preclude the presence of additional identical elements.

[0269] Titles and subtitles (if any) are used for convenience only and do not limit the invention. The terms "exemplary" are used to indicate that they are intended as examples or illustrations. Within the scope of the use of terms such as "comprising," "having," etc., such terms are intended to be inclusive in a manner similar to the term "comprising," as "comprising" is interpreted when used as a transitional word in the claims. Relational terms such as "first" and "second" may be used to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between these entities or actions.

[0270] Phrases such as aspect, that aspect, on the other hand, some aspects, one or more aspects, implementation, that implementation, another implementation, some implementations, one or more implementations, embodiment, that embodiment, another embodiment, some embodiments, one or more embodiments, configuration, that configuration, another configuration, some configurations, one or more configurations, subject matter, disclosure, this disclosure, other variations thereof, etc., are used for convenience and do not imply that disclosures associated with such phrases are essential to the subject matter, or that such disclosures apply to all configurations of the subject matter. Disclosures associated with such phrases may apply to all configurations or one or more configurations. Disclosures associated with such phrases may provide one or more examples. Phrases such as aspect or some aspects may refer to one or more aspects, and vice versa, and this similarly applies to other foregoing phrases.

[0271] The phrase "at least one of" following a series of items, along with the terms "and" or "or" used to separate any items, modifies the list as a whole, not each member of the list. The phrase "at least one" does not require the selection of at least one item; rather, it allows for the inclusion of at least one of any one item, and / or at least one of any combination of items, and / or at least one of each item. For example, each of the phrases "at least one of A, B, and C" or "at least one of A, B, or C" refers to only A, only B, or only C; any combination of A, B, and C; and / or at least one of each of A, B, and C.

[0272] It should be understood that the specific order or hierarchy of the disclosed steps, operations, or processes is an illustration of exemplary methods. Unless otherwise expressly stated, it should be understood that the specific order or hierarchy of steps, operations, or processes may be performed in a different order. Some steps, operations, or processes may be performed simultaneously, or may be performed as part of one or more other steps, operations, or processes. The appended method claims (if any) present elements of various steps, operations, or processes in a sample order, but this does not imply limitation to the specific order or hierarchy presented. These may be performed serially, linearly, in parallel, or in different orders. It should be understood that the described instructions, operations, and systems can generally be integrated together in a single software / hardware product or packaged into multiple software / hardware products.

[0273] This disclosure is provided to enable any person skilled in the art to practice the various aspects described herein. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring the concept of the subject matter. This disclosure provides various examples of the subject matter, and the subject matter is not limited to these examples. Various modifications to these aspects will be apparent to those skilled in the art, and the principles described herein can be applied to other aspects.

[0274] The various aspects described herein, and all structural and functional equivalents known now or hereafter to those skilled in the art, are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be made public, whether or not such disclosure is explicitly stated in the claims.

[0275] The title, background art, description of the drawings, abstract, and figures are incorporated herein by reference and are provided as illustrative examples rather than as limiting descriptions. It should be understood at the time of filing that they are not intended to limit the scope or meaning of the claims. Furthermore, in the detailed description, it will become apparent that the description provides illustrative examples and that various features are grouped together in various embodiments for the purpose of simplifying the disclosure. The approach of this disclosure should not be construed as reflecting an intention to require more features than expressly recited in each claim. Rather, as reflected in the following claims, the inventive subject matter lies in all features of fewer than those in a single disclosure configuration or operation. The appended claims are incorporated herein by reference, wherein each claim is independently claimed as a separate subject matter.

[0276] The claims are not intended to be limited to the aspects described herein, but rather to conform to the full scope consistent with the language claims and to include all legal equivalents. Nevertheless, no claim is intended to include subject matter that does not meet the requirements of applicable patent law, nor should they be interpreted in this manner.

Claims

1. An access point (AP) in a wireless network, comprising: Memory; as well as A processor, coupled to a memory, is configured to: Generate a trigger frame that requests a response from one or more stations (STAs) and includes information for dynamic subband handover operations. The trigger frame includes a common information field and one or more user information fields. The common information field provides information common to one or more STAs, and each user information field provides information specific to a particular STA among the one or more STAs. Send a trigger frame to one or more STAs to request a dynamic subband handover operation; and Based on whether a response to the trigger frame is received from one or more STAs, it is determined whether the dynamic subband handover operation was successfully executed at one or more STAs.

2. The AP according to claim 1, wherein, The public information field includes a trigger frame that triggers a dynamic subband handover operation for at least one or more STAs, and one or more user information fields that include indications of information associated with the dynamic subband handover operation.

3. The AP according to claim 1, wherein, One or more user information fields are addressed to the Dynamic Subband Operation (STA) and include information associated with the Dynamic Subband Switching Operation.

4. The AP according to claim 1, wherein, The triggering frame is a Multi-User Request Transmit (MU-RTS) frame, a Block Acknowledgment Request (BAR) frame, or a Buffer Status Report Polling (BSRP) frame.

5. The AP according to claim 1, wherein, The processor is also configured to: It was determined that no frame responding to the trigger frame was received on the main channel; and It has been determined that the triggering operation has failed at one or more STAs.

6. The AP according to claim 1, wherein, The processor is also configured to: Receive a frame in response to a trigger frame from at least one of one or more STAs on any subchannel of a transmission opportunity (TXOP); Confirm that the subband switching operation was successful at at least one of the one or more STAs; and Initiate a transmission to at least one of one or more STAs, while also transmitting a signal to occupy the medium on the main channel.

7. The AP according to claim 1, wherein, The trigger frame includes a field that contains information used by one or more STAs to determine the transmit power in order to send a response.

8. The AP according to claim 1, wherein, The effects of the residual carrier frequency offset between the trigger frame and the expected response of a specific dynamic subband operation STA are mitigated by one or more of the following: The transmission parameters that limit the response frame include the modulation and coding scheme or the duration of the response transmission; as well as Include a field in the trigger frame that includes information used by a specific dynamic subband operation STA to determine the residual carrier frequency offset after performing a channel switch to the indicated subband.

9. The AP according to claim 1, wherein, The resource allocation to one or more dynamic subband STAs indicated in the trigger frame comes from a set of subbands negotiated between the AP and one or more dynamic subband STAs.

10. The AP according to claim 1, wherein, The trigger frame indicates whether one or more STAs need to perform energy detection or preamble detection on a new subchannel within a certain amount of time after the end of the trigger frame before transmitting a response.

11. A station (STA) in a wireless network, comprising: Memory; as well as A processor, coupled to a memory, is configured to: Receive a trigger frame from the access point (AP) requesting a dynamic subband handover operation. The trigger frame includes a common information field and one or more user information fields. The common information field provides information common to one or more STAs, and each user information field provides information specific to a particular STA among the one or more STAs. Perform the dynamic subband switching operation requested in the trigger frame; and Send a transmission permission response frame to the AP in response to the trigger frame.

12. The STA according to claim 11, wherein, The public information field includes a trigger frame that triggers a dynamic subband handover operation for at least one or more STAs, and one or more user information fields that include indications of information associated with the dynamic subband handover operation.

13. The STA according to claim 11, wherein, The triggering frame is a Multi-User Request Transmit (MU-RTS) frame, a Block Acknowledgment Request (BAR) frame, or a Buffer Status Report Polling (BSRP) frame.

14. A computer-implemented method for wireless communication of an access point (AP) in a wireless network, the method comprising operations performed by at least a processor in the AP according to any one of claims 1 to 10.

15. A computer-implemented method for wireless communication of a station (STA) in a wireless network, the method comprising operations performed by at least a processor in the STA according to any one of claims 11 to 13.

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