Data transmission methods

Abstract

This invention provides a data transmission method. According to one embodiment, first and second trigger frames are received from a wireless access point (AP) at a wireless station (STA) via first and second wireless links, respectively. When the difference between the end time of a data frame transmitted in response to the first trigger frame and the end time of a data frame transmitted in response to the second trigger frame is greater than a predetermined value, first and second data frames are transmitted via the first and second wireless links in response to the first and second trigger frames, respectively, to prevent interference.

Description

[Technical Field]

[0001] The embodiments of the present invention generally relate to the field of wireless communication. More specifically, the embodiments of the present invention relate to systems and methods for triggering uplink access for multiple link operations in a wireless network. [Background Technology]

[0002] Modern electronic devices typically use Wi-Fi to wirelessly send and receive data with other electronic devices, and many of these devices are "dual-band" devices, which include at least two wireless transceivers capable of operating in different frequency bands (e.g., 2.4 GHz, 5 GHz, and 6 GHz). In most cases, wireless devices can only communicate on a single frequency band at a time. For example, older, low-power devices, such as battery-powered devices, typically operate in the 2.4 GHz band. Newer devices and those requiring greater bandwidth typically operate in the 5 GHz band. The availability of the 6 GHz band is a recent development that offers higher performance, lower latency, and faster data rates.

[0003] However, in some cases, using a single frequency band may not meet the bandwidth requirements of certain devices. Therefore, some emerging methods for wireless communication increase communication bandwidth by operating simultaneously on multiple frequency bands (technically known as link aggregation or multi-link operation).

[0004] When wireless devices simultaneously transmit and receive data in multi-link operation, in-device coexistence (IDC) interference can cause substantial performance loss between multiple wireless links. IDC interference caused by simultaneous transmission and reception in the 2.4 GHz and 5 GHz bands is generally negligible. However, IDC interference caused by simultaneous transmission and reception in the 5 GHz and 6 GHz bands can severely impact performance and lead to frequent packet loss.

[0005] Therefore, to avoid IDC interference, wireless devices should not simultaneously send and receive frames on multiple links. However, since wireless devices cannot easily determine when frame transmission ends, it is currently difficult to synchronize transmissions on multiple wireless links to ensure that wireless devices do not simultaneously send and receive frames on multiple wireless links. Therefore, multi-link operation is susceptible to IDC interference, which severely impacts the performance of overlapping (unaligned) frame transmissions on multiple wireless links.

[0006] The IEEE 802.11ax standard introduced uplink transmission (UL) involving multiple non-access point (AP) stations (STAs) simultaneously transmitting to an AP station (called Triggered Uplink Access, TUA). This mechanism uses an 802.11 MAC frame called a trigger frame sent by the AP station. The HE-enabled AP station sends the trigger frame before the transmissions of other non-AP stations to initiate orthogonal frequency division multiple access (OFDMA) or multi-user multiple-input multiple-output (MU-MIMO) transmission. The trigger frame identifies the non-AP stations participating in the UL MU transmission and allocates resource elements (RUs) to them. Each non-AP station receiving the trigger frame uses the RU allocated to each station to send a trigger-based (TB) physical layer conformance procedure (PLCP) Protocol Data Unit (PPDU) back to the AP. Therefore, a method is needed to perform constrained multilink operation using triggered uplink access, which can prevent IDC interference caused by the transmission of TB PPDUs while a trigger frame has already been received on another radio link of a non-AP STA. [Summary of the Invention]

[0007] Therefore, embodiments of the present invention provide a method for TB uplink transmission in constrained multilink operation, which substantially prevents interference caused by wireless devices (e.g., wireless STAs or APs) simultaneously transmitting and receiving data (e.g., PPDUs).

[0008] According to one embodiment, a method for data transmission based on multi-link triggering in a wireless network is disclosed. The method includes sending a first trigger frame from a first auxiliary wireless access point (AP) of a multi-band wireless AP to a wireless station (STA) via a first wireless link, wherein the first trigger frame includes a carrier sense (CS) required field with a value of 1; sending a second trigger frame from a second auxiliary wireless AP to the wireless STA via a second wireless link; and transmitting the second trigger frame from the second auxiliary wireless AP to the wireless STA via the second wireless link when the difference between the start time of the Entity Layer Conformity Protocol Data Unit (PPDU) sent by the wireless STA in response to the first trigger frame and the end time of the second trigger frame is equal to or greater than a predetermined margin.

[0009] According to some embodiments, a predetermined margin is determined based on the calculation aSIFSTime + aSignalExtension – aRxTxTurnaroundTime.

[0010] According to some embodiments, the predetermined margin is 12 μs.

[0011] According to some embodiments, a predetermined margin is determined based on the requirements of the wireless AP.

[0012] According to some embodiments, the first wireless link includes a 6GHz wireless link, and the second wireless link includes a 5GHz wireless link.

[0013] According to various embodiments, a method for data transmission based on multi-link triggering in a wireless network is disclosed. The method includes receiving a first trigger frame and a second trigger frame from a wireless access point (AP) at a wireless station (STA) via a first wireless link and a second wireless link, respectively; calculating the difference between the end time of a first Entity Layer Conformity Protocol Data Unit (PPDU) carrying the first trigger frame and the end time of a second PPDU carrying the second trigger frame; and, when the difference between the end times of the first PPDU and the second PPDU is greater than a predetermined value, transmitting a first data frame and a second data frame via the first wireless link and the second wireless link, respectively, in response to the first trigger frame and the second trigger frame.

[0014] According to some embodiments, a predetermined value is determined based on the short interframe space (SIFS) – (10% x aSlotTime), where aSlotTime is determined according to the specifications of the wireless network.

[0015] According to some embodiments, the predetermined value is selected from the following values: 4μs, 8μs, and 16μs.

[0016] According to some embodiments, the first PPDU and the second PPDU are formatted using one of the following: non-HT, HT, VHT, HE, and EHT formats.

[0017] According to some embodiments, the method includes adjusting the end time of the first PPDU by adjusting the MAC filling of the first PPDU.

[0018] According to some embodiments, the method includes adjusting the end time of the first PPDU by adjusting the PHY filling of the first PPDU.

[0019] According to some embodiments, the method includes adjusting the end time of the first PPDU by adjusting the PE frame of the first PPDU.

[0020] According to some embodiments, the method includes: a first wireless link including a 6 GHz wireless link and a second wireless link including a 5 GHz wireless link.

[0021] According to some embodiments, the method includes adjusting the end time of the first PPDU to adequately mitigate coexisting interference within the device.

[0022] According to another embodiment, a method for data transmission based on multi-link triggering in a wireless network is disclosed. The method includes receiving a first trigger frame and a second trigger frame from a wireless access point (AP) at a wireless station (STA) via a first wireless link and a second wireless link, respectively; transmitting a first data frame and second data in response to the first trigger frame and the second trigger frame transmitted to the wireless AP via the first wireless link and the second wireless link, respectively; and receiving an acknowledgment (ACK). The transmission includes calculating the difference between the end time of a first Entity Layer Conformity Protocol Data Unit (PPDU) carrying the first data frame and the end time of a second PPDU carrying the second data frame; and setting a UL length field based on the difference between the end times of the first PPDU and the second PPDU to prevent interference leakage between the first and second wireless links upon receiving the ACK.

[0023] According to some embodiments, the UL length field of the first PPDU is set such that the difference between the end time of the first PPDU and the end time of the second PPDU is greater than SIFS - (10% × aSlotTime), where aSlotTime is determined according to the specifications of the wireless AP. According to some embodiments, setting the UL length field of the first PPDU prevents the transmission of a second data frame during ACK reception.

[0024] According to some embodiments, the first wireless link includes a 6GHz wireless link, and the second wireless link includes a 5GHz wireless link. According to some embodiments, the method includes performing PHY padding on the ACK.

[0025] According to some embodiments, the method includes performing MAC stuffing on the ACK. [Attached Image Description]

[0026] Various embodiments of this disclosure, presented as examples, will be described in detail with reference to the following accompanying drawings, in which:

[0027] Figure 1 This is a block diagram illustrating exemplary synchronous multi-link transmission according to an embodiment of the present invention.

[0028] Figure 2 This is a block diagram depicting an exemplary restricted multilink operation using triggered uplink access according to an embodiment of the present invention, which causes IDC interference due to simultaneous transmission and reception of data by a wireless STA.

[0029] Figure 3 This is a block diagram of an exemplary restricted multilink operation using triggered uplink access according to an embodiment of the present invention, which is used to prevent IDC interference caused by simultaneous transmission and reception of data by a wireless STA.

[0030] Figure 4 This is a block diagram of an exemplary restricted multilink operation using triggered uplink access according to an embodiment of the present invention, which results in interference leakage due to the wireless STA sensing the channel during SIFS.

[0031] Figure 5 This is a block diagram of an exemplary restricted multilink operation using triggered uplink access according to an embodiment of the present invention, which is used to prevent interference leakage caused by the wireless STA sensing the channel during SIFS.

[0032] Figure 6 This is a block diagram of an exemplary restricted multilink operation using triggered uplink access according to an embodiment of the present invention, which results in reception errors due to interference leakage between wireless links.

[0033] Figure 7 This is a block diagram illustrating an exemplary restricted multilink operation using triggered uplink access to prevent interference leakage, according to an embodiment of the present invention.

[0034] Figure 8 This is a flowchart illustrating an exemplary sequence of computer implementation steps for performing restricted multi-link triggered uplink access to prevent IDC interference, according to embodiments of the present invention.

[0035] Figure 9 This is a flowchart of an exemplary sequence of computer implementation steps for performing constrained multi-link triggered uplink access to prevent a wireless link from entering a busy state due to interference leakage, according to an embodiment of the present invention.

[0036] Figure 10 This is a flowchart of an exemplary sequence of computer implementation steps for performing constrained multi-link triggered uplink access to prevent interference leakage between wireless links, according to an embodiment of the present invention.

[0037] Figure 11 This is a block diagram depicting an exemplary computer system platform on which embodiments of the present invention can be implemented.

Detailed Implementation Methods

[0038] Several embodiments will now be described in detail. Although the subject matter will be described in conjunction with alternative embodiments, it should be understood that they are not intended to limit the claimed subject matter to these embodiments. Rather, the claimed subject matter is intended to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of the claimed subject matter as defined by the claims.

[0039] Furthermore, numerous specific details are set forth in the following detailed description to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will recognize that embodiments can be practiced without these specific details or their equivalents. In other instances, well-known methods, processes, components, and circuits have not been described in detail to avoid unnecessarily obscuring aspects and features of the subject matter.

[0040] The following detailed description is presented and discussed in relation to the method. Although the steps and sequence thereof are disclosed herein in the accompanying drawings (e.g., Figures 8-10) describing the operation of the method, these steps and sequences are exemplary. Embodiments are well suited for performing various other steps or variations thereof listed in the flowcharts of the accompanying drawings, and for performing them in a different order than that depicted and described herein.

[0041] This description presents certain parts of a detailed account based on the procedures, steps, logic blocks, processes, and other symbolic representations of operations on data bits that can be executed on computer memory. These descriptions and representations are the means by which those skilled in the art of data processing most effectively communicate the substance of their work to others in the field with ordinary knowledge. Here, procedures, computer-executed steps, logic blocks, processes, etc., are generally considered as a self-consistent sequence of steps or instructions that lead to the desired result. These steps are those that require physical manipulation of physical quantities. Typically, although not essential, these quantities take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, and otherwise manipulated in a computer system. Primarily for general reasons, it has sometimes proven convenient to refer to these signals as bits, values, elements, symbols, characters, items, numbers, etc.

[0042] However, it should be remembered that all these and similar terms should be associated with appropriate physical quantities and are merely convenient labels applied to those quantities. Unless otherwise explicitly stated in the discussion below, it should be understood that throughout the discussion, terms such as “access,” “configuration,” “coordination,” “storage,” “transmission,” “retransmission,” “authentication,” “identification,” “request,” “report,” and “determine” are used to refer to the operation and processing of a computer system or similar electronic computing device that processes and converts data represented as physical (electronic) quantities within the computer system’s registers and memory into other data similarly represented as physical quantities in the computer system’s memory or registers or other such information storage, transmission, or display devices.

[0043] Synchronization of uplink access triggered by EHT multi-link

[0044] As used in this article, the term "EHT" generally refers to a new generation of wireless communication (Wi-Fi) known as Extremely High Throughput (EHT), and is defined according to the IEEE 802.11be standard. The term "station" (STA) generally refers to an electronic device capable of sending and receiving data via Wi-Fi, which does not operate as an access point (AP).

[0045] Compared to traditional wireless communication technologies, multilink operation can provide higher network throughput and greater network flexibility. Embodiments of this invention substantially prevent interference caused by simultaneous transmission and reception of data in restricted multilink operation of wireless networks. Multilink operation can be performed between multiple linked devices (MLDs) comprising multiple auxiliary STAs (non-AP STAs or AP-STAs) operating on different wireless links.

[0046] about Figure 1According to embodiments of the present invention, an exemplary wireless communication system 100 including a multi-band cooperative AP 105 and a multi-band cooperative STA 155 is depicted. The multi-band cooperative AP 105 and the multi-band cooperative STA 155 are examples of MLDs. The multi-band cooperative AP 105 includes a 5 GHz transceiver 110 and a 2.4 GHz transceiver 115. According to embodiments of the present invention, the multi-band cooperative AP 105 may also use other types of transceivers operating on different frequency bands such as 6 GHz and above. The transceivers 110 and 115 of the AP 105 exchange data and information with a cooperative management unit 120 that coordinates the information transmitted and / or received by the transceivers 110 and 115. The AP 105 can be considered as including two AP instances or “attached” APs to use the 5 GHz transceiver 110 and the 2.4 GHz transceiver 115.

[0047] The multi-band cooperative STA 155 includes a 5 GHz transceiver 160 and a 2.4 GHz transceiver 165. According to some embodiments of the invention, the multi-band cooperative STA 155 can also use other types of transceivers operating on different frequency bands, such as 6 GHz and above. Transceivers 160 and 165 of STA 155 exchange data and information with a cooperative management unit 170, which coordinates the transmission and reception of information by transceivers 160 and 165 using 5 GHz wireless communication and 2.4 GHz wireless communication, respectively, although any well-known wireless communication frequency band (e.g., 6 GHz) can be used. STA 155 can be considered as including two STA instances or “attached” STAs for communication using 5 GHz transceiver 160 and 2.4 GHz transceiver 165.

[0048] The multi-band cooperative AP 105 and multi-band cooperative STA 155 have the capability to transmit and receive simultaneously using different radio frequency bands. Transmitters operating on different frequency bands can perform independent clear channel assessments (CCA) using joint or intentional transmissions. Furthermore, full-duplex communication can be enabled through independent multi-band operation using FDD mode.

[0049] Simultaneous transmission of frames across multiple frequency bands by STA 155 can reduce latency and improve peak throughput. However, in some cases, simultaneous transmission of frames across multiple frequency bands can degrade the performance of the STA 155's basic service set (BSS). Therefore, AP 105 can control which STAs are granted multi-band channel access, and access can be terminated by the AP at any time, for example, based on changing network conditions or requirements.

[0050] Depending on conditions such as traffic load, non-AP STAs can use fewer links than all supported / available links to reduce energy consumption. Furthermore, non-AP STAs can apply independent power management to each link, and the AP can provide TID-to-link mapping information for each link. Based on the Basic Service Set (BSS) Quality of Service (QoS) policy, the AP can allocate traffic to different links according to traffic type (e.g., voice, video, data, etc.). For example, frames belonging to the first Traffic Identifier (TID 1) can be assigned to the first link, and frames belonging to the second Traffic Identifier (TID 2) can be assigned to the second link. In this case, the AP can provide TID-to-link mapping information to the wireless STA for both links, where some data can only be transmitted on the first link, and other data can only be transmitted on the second link.

[0051] Data transmitted via a first wireless link (e.g., a 5GHz wireless link provided by 5GHz transceivers 110 or 160) can be retransmitted on a different wireless link. For example, if data transmission via the 5GHz wireless link fails (e.g., no acknowledgment is received), the data can be retransmitted via a 2.4GHz wireless link provided by 2.4GHz transceivers 115 / 165. Data can be retransmitted via a second link when an unplanned channel switch occurs, or when delay-sensitive packets are transmitted on multiple links. Furthermore, according to embodiments of the invention, data transmissions (e.g., PPDUs) can be initially encoded for transmission on the first wireless link (e.g., a 2.4GHz or 5GHz wireless link), and retransmitted data can be prepared for transmission, encrypting the data for retransmission in a multi-link environment.

[0052] Figure 2An exemplary restricted multilink operation 200, triggered by an uplink access, is depicted according to an embodiment of the invention. This operation results in IDC interference caused by simultaneous data transmission or reception by wireless STAs (e.g., non-AP wireless STAs or multilink devices (e.g., MLDs)). Figure 2 In this process, the wireless AP 205 sends a trigger frame 215 to the wireless STA 210 to request an uplink response frame via the 5GHz wireless link 220. The AP 205 then sends a trigger frame 225 to the wireless STA 210 to request an uplink response frame via the 6GHz wireless link 230 before the transmission of the trigger frame 215 to the wireless STA 210 is complete. Before the STA 210 has completed receiving the trigger frame 225, the wireless STA 210 sends an EHT TB PPDU 235 (in response to the trigger frame 215), resulting in IDC interference 240, which is caused by the simultaneous transmission and reception of data in multi-link operation. According to an embodiment of the invention, when the STA sends an EHT TB PPDU on a separate wireless link in response to the trigger frame within a specified margin, the wireless AP is restricted from scheduling PPDUs carrying the trigger frame to the STA to prevent IDC interference 240. Figure 2 In the example, multi-band AP 205 is an MLD that includes multiple affiliated APs (e.g., a first affiliated AP running on 6GHz link 220 and a second affiliated AP running on 5GHz link 230), and multi-band STA 210 is an MLD that includes multiple affiliated STAs (e.g., a first affiliated STA running on 6GHz link 220 and a second affiliated STA running on 5GHz link 230).

[0053] Figure 3 An exemplary restricted multilink operation 300 is depicted according to an embodiment of the present invention, using triggered uplink access to prevent IDC interference caused by simultaneous transmission and reception of data by multi-band wireless STAs. Figure 3 In this scenario, a multi-band wireless AP 305 sends a trigger frame 315 to a multi-band wireless STA 310 on the 5GHz wireless link 320 to request an uplink response frame. Before the transmission of trigger frame 315 to the wireless STA 310 is complete, the AP 305 sends a trigger frame 325 to the wireless STA 310 on the 6GHz wireless link 330 to request an uplink response. Before the STA 310 has completed receiving trigger frame 325, the wireless STA 310 sends a TB PPDU 335 (in response to trigger frame 315), thus causing IDC interference. Figure 3For example, when the difference between the end times of the transmissions of individual PPDUs (e.g., trigger frames 315 and 325) is less than the Short Interframe Spacing (SIFS) - (10% × aSlotTime), the wireless AP 305 can schedule a PPDU carrying a trigger frame to the STA 310, where aSlotTime is a fixed / predefined value. Figure 3 As shown, because the minimum inter-frame interval 340 is not less than SIFS 365, the transmit 315 and receive 335 of AP305 advantageously do not overlap. For example, this can be achieved using MAC padding 345, PHY padding 350, and / or PE 355. Figure 3 The start and end times are aligned. SIFS time can be calculated as: SIFS = aSIFSTime + aSignalExtension. According to some embodiments, aSIFSTime is fixed at 10μs at 5GHz and 16μs at 2.4GHz, and for the 5GHz band, the value of aSignalExtension is 0μs, while for the 2.4GHz band, the value of aSignalExtension is 6μs. Request PPDUs can be sent in any known PPDU format, such as non-HT, HT, VHT, HE, EHT, etc.

[0054] According to one embodiment, the start and end times of multilink transmissions are synchronized within a margin equal to SIFSTime + aSignalExtension, using, for example, MAC padding, PHY padding, and / or packet extension (PE).

[0055] According to some embodiments, the margin is fixed at 16 μs. Specifically, for the 2.4 GHz band, the value of aSIFSTime is 10 μs, for the 5 GHz band, the value of aSIFSTime is 16 μs; for the 2.4 GHz band, the value of aSignalExtension is 6 μs; and for the 5 GHz band, it is 0 μs.

[0056] about Figure 4 According to an embodiment of the invention, an exemplary constrained multilink operation 400 for triggering uplink access is depicted, which results in interference leakage caused by the wireless STA sensing channel during SIFS. Figure 4In this scenario, the multi-band AP 405 sends a trigger frame 415 to the multi-band wireless STA 410 to request an uplink response frame on the 5GHz wireless link 420 and a trigger frame 425 on the 6GHz wireless link 430. A TB PPDU 435 is sent by the wireless STA 410 (responding to trigger frame 415), and the difference between the end time of trigger frame 415 and the start time of TB PPDU 435 is less than SIFS - (10% × aSlotTime). During SIFS 440, the STA 410 senses the 6GHz channel 430 and changes the 5GHz carrier sense (CS) when the IDC interference exceeds the energy detection (ED) threshold. In this case, the STA 410 will not respond to trigger frame 425 if the CS required field of trigger frame 425 is set to 1.

[0057] about Figure 5 According to an embodiment of the invention, an exemplary restricted multilink operation 500 is shown, which uses triggered uplink access to prevent interference leakage caused by the sensing channel during SIFS by a wireless STA. Figure 5 In this configuration, the wireless AP 505 sends a trigger frame 515 to the wireless STA 510 to request an uplink response frame on the 5GHz wireless link 520 and a trigger frame 525 on the 6GHz wireless link 530. The STA 510 then wirelessly transmits a TB PPDU 535 in response to the trigger frame 515. The Carrier Sense (CS) required field in both trigger frames 515 and 525 is set to 1. Therefore, before transmission, the AP 505 determines whether the difference 540 between the end time of the trigger frame 525 and the start time of the TB PPDU 535 is greater than or equal to aCCATime. If the difference 540 is greater than or equal to aCCATime, the STA 510 can perform channel sensing during SIFS and respond with the requested TB PPDU 535 without causing interference. Otherwise, if the difference 540 between the end time of the trigger frame 525 and the start time of the TB PPDU 535 is less than aCCATime, transmission is restricted. According to some embodiments, aCCATime is 4 μs or 8 μs. According to some embodiments, the aCCATime of the wireless STA is sent by the wireless STA to the associated wireless AP.

[0058] According to some embodiments, if TB PPDUs transmitted over different links are not fully synchronized at the OFDM symbol level, the wireless STA does not respond to a trigger frame that sets the required CS field to 1. According to some embodiments, the STA reports any interference leakage from the first link, which causes the CS state of the second link to switch to a busy state (when the interference is greater than the ED threshold). For concurrent TB PPDU transmissions on the first and second links, the AP provides OFDM symbol alignment between the PPDU containing the trigger frame and the responding TB PPDU. In other words, the end time of the PPDU containing the trigger frame is aligned within the OFDM symbol duration (e.g., 4 µs), and therefore the start time of the responding TB PPDU is also aligned within the OFDM symbol duration (e.g., 4 µs).

[0059] According to some embodiments, when the wireless AP cannot meet synchronization requirements (e.g., the difference between the end times of multiple PPDUs is less than SIFS - (10% × aSlotTime)), the wireless AP will not simultaneously trigger the transmission of multiple TB PPDUs requiring a CS. Therefore, the wireless AP cannot simultaneously send more than one PPDU containing a trigger frame with the required CS set to 1. However, when one trigger frame includes a CS required field set to 1 and another trigger frame includes a CS required field set to 0, the AP can simultaneously send more than one PPDU containing a trigger frame.

[0060] In some cases, TB PPDUs transmitted on multiple links use different TXVECTOR parameters (e.g., GI or LTF type), making it difficult to synchronize the start and end times of transmissions on multiple links. To relax the requirements for multi-link operation, the start and end times of transmissions on multiple links can be synchronized by the wireless STA using MAC padding, PHY padding, or packet extension (PE) with a margin of (aSIFSTime + aSignalExtension) / 2. The transmission opportunity (TXOP) holder can adjust the inter-frame spacing (IFS) between SIFS and SIFS + SIFS / 2 so that the IFS is different for each link. In these embodiments, if the wireless AP determines that the wireless STA may transmit a frame on the first wireless link after the trigger frame requested during SIFS, the AP will not transmit a trigger frame with the desired CS equal to 1 on the second link.

[0061] According to some embodiments, when a PPDU containing a trigger frame is received, and a PPDU from a STA associated with the same wireless STA is scheduled to be transmitted within a predetermined margin, the wireless AP performing TB multilink access is restricted from sending a trigger frame with the CS required subfield set to 1 to the wireless STA. According to some embodiments, the margin is determined based on (aSIFSTime + aSignalExtension - aRxTxTurnaroundTime), and aRxTxTurnaroundTime can be equal to 4 μs. For example, when a PPDU from another STA associated with a multi-band STA is scheduled to be transmitted before a timer expires, the wireless AP associated with the multi-band AP does not send a trigger frame with the CS required subfield set to 1 to the STA associated with the unified multi-band STA, where the timer value is 12 μs (aSIFSTime + aSignalExtension – aRxTxTurnaroundTime, where aRxTxTurnaroundTime equals 4 μs). In this case, the wireless AP and wireless STA follow the CS requirements as defined in the IEEE 802.11ax specification (e.g., 26.5.2 UL MU operation).

[0062] According to some embodiments, an AP can allocate services to different links based on the QoS policy of a Basic Service Set (BSS). For example, when a frame belonging to Traffic Identifier (TID) 1 is allocated to link 1 and a frame belonging to TID 2 is allocated to link 2, the HE TB PPDU transmitted on multiple links carries the frame belonging to the QoS policy. For example, if the wireless AP allocates a frame belonging to TID 1 to link 1, then the HE TB PPDU transmitted through link 1 only carries the frame belonging to TID 1. When using MAC padding, the wireless STA can aggregate frames determined by the wireless AP to be allocated to other links. The AP can indicate in a trigger frame whether the wireless STA can aggregate frames allocated to other links.

[0063] about Figure 6 According to an embodiment of the invention, an exemplary restricted multilink operation 600 using triggered uplink access is shown, which results in reception errors due to interference leakage between wireless links. Figure 6In this configuration, wireless AP 605 sends trigger frame 615 to wireless STA 610 to request an uplink response frame on 6GHz wireless link 620 and trigger frame 625 on 6GHz wireless link 630. EHT TB PPDU 635 is sent by wireless STA 610 in response to trigger frame 615. The length of the EHT TB PPDU (e.g., EHT TB PPDU 635 and 640) is determined based on the individual trigger frames sent on the links associated with the EHT TB PPDU. Figure 6 In this case, the difference between the end times of multiple EHT TB PPDUs is greater than SIFS - (10% x aSlotTime), resulting in interference leakage, and the wireless STA is unable to decode the response frame (block ACK) 645.

[0064] about Figure 7 This describes an exemplary restricted multilink operation 700 using triggered uplink access to prevent interference leakage according to an embodiment of the present invention. Figure 7 In this configuration, the wireless AP 705 sends a trigger frame 715 to the wireless STA 710 to request an uplink response frame via the 5GHz wireless link 720, and sends a trigger frame 725 via the 6GHz wireless link 730. A TBPPDU 735 is sent by the wireless STA 710 in response to trigger frame 715, and a TBPPDU 740 is sent by the wireless STA 710 in response to trigger frame 725. The UL length subfield values ​​in trigger frames 715 and 725 are set such that the difference between the end times of TBPPDUs 735 and 740 is less than or equal to SIFS - (10% × aSlotTime). According to some embodiments, SIFS - (10% × aSlotTime) is the maximum limit for PPDU end time alignment; of course, stricter synchronization requirements can be applied (e.g., SIFS - (10% × aSlotTime) – aCCATime or 8 μs).

[0065] Figure 8 Flowchart 800 depicts an exemplary sequence of computer implementation steps for performing restricted multilink-triggered uplink access to prevent IDC interference, according to an embodiment of the present invention.

[0066] In step 805, first and second trigger frames are received from the wireless access point (AP) of the wireless station (STA) via the first and second wireless links, respectively.

[0067] In step 810, the difference between the end time of the PPDU carrying the first trigger frame and the end time of the PPDU carrying the second trigger frame is calculated.

[0068] In step 815, when the difference between the end time of the PPDU carrying the first trigger frame and the end time of the PPDU carrying the second trigger frame is less than a predetermined margin, in response to the first and second trigger frames, a first data frame and a second data frame are transmitted in the PPDU via the first and second wireless links, respectively. According to some embodiments, the predetermined margin is calculated as: SIFS - (10% × aSlotTime). According to some embodiments, SIFS - (10% × aSlotTime) is the maximum limit for PPDU end time alignment; of course, stricter synchronization requirements can be applied (e.g., SIFS - (10% × aSlotTime) – aCCATime or 8 μs). According to some embodiments, for example, MAC padding, PHY padding, and / or PE are used to adjust the PPDU end time.

[0069] Figure 9 Flowchart 900 depicts an exemplary sequence of steps performed by a computer according to an embodiment of the present invention, which are used to perform constrained multilink triggered uplink access to prevent the wireless link from entering a busy state due to interference leakage.

[0070] In step 905, during multi-link operation, a first trigger frame is transmitted in a PPDU from a wireless access point (AP) to a wireless station (STA) via a first wireless link. The wireless AP and wireless STA are MLDs that can communicate via multiple wireless links. The first trigger frame includes a CS required field with a value of 1, indicating that channel sensing was performed prior to the wireless STA transmitting the PPDU in response to the trigger frame.

[0071] In step 910, the wireless AP determines that it is scheduled to send a second trigger frame in the PPDU via the second wireless link. The second trigger frame is sent by the AP instance associated with the wireless AP to the STA instance associated with the wireless STA.

[0072] In step 915, when the difference between the start time of the PPDU sent by the wireless STA in response to the first trigger frame and the end time of the second trigger frame is greater than or equal to a predetermined margin, the wireless AP (e.g., an AP belonging to the wireless AP) sends the second trigger frame. According to some embodiments, the predetermined margin is set according to aCCATime defined by the wireless AP. For example, aCCATime can be determined according to aSIFSTime + aSignalExtension – aRxTxTurnaroundTime, where aRxTxTurnaroundTime is equal to 4 μs. For example, the predetermined margin can be 12 μs. According to some embodiments, for example, MAC padding, PHY padding, and / or PE are used to adjust the end time of the PPDU.

[0073] Figure 10 This is process 1000, which describes an exemplary sequence of computer implementation steps for performing constrained multi-link triggered uplink access to prevent interference leakage between a first wireless link and a second wireless link, according to embodiments of the present invention.

[0074] In step 1005, first and second trigger frames are received from the wireless access point (AP) of the wireless station (STA) via the first and second wireless links, respectively.

[0075] In step 1010, the difference between the end time of the PPDU carrying the first data frame and the end time of the PPDU carrying the second data frame is calculated.

[0076] In step 1015, the UL length field of the first and / or second PPDU is adjusted so that the difference between the end times of the multiple response PPDUs is less than or equal to SIFS - (10% × aSlotTime).

[0077] In step 1020, in response to a first trigger frame and a second trigger frame on the first and second wireless links, respectively, a first data frame and a second data frame are transmitted in the PDDU. The end times of the data frames are aligned substantially within a predetermined margin to advantageously prevent channel leakage interference caused by the reception of subsequent response frames (e.g., ACK or block ACK) at the wireless STA. According to some embodiments, for example, MAC padding, PHY padding, and / or PE are used to adjust the end time of the PDDU.

[0078] In step 1025, a response frame is received in response to the wireless AP receiving the first data frame, and interference leakage is essentially prevented.

[0079] Embodiments of the present invention relate to an electronic system performing multilink operation in a wireless network. Multilink operation may include constrained multilink operation constrained to prevent or mitigate IDC interference, for example, by aligning the start / end times of received / transmitted frames within a predetermined margin, thereby substantially preventing simultaneous transmission and reception. For example, MAC padding, PHY padding, and / or packet expansion (PE) may be used to align frame timing. The following discussion describes one such exemplary electronic system or computer system that can be used as a platform for implementing embodiments of the present invention. For example, exemplary computer system 1112 may be a wireless access point or wireless station.

[0080] exist Figure 11In the example, the exemplary computer system or wireless device includes a central processing unit (e.g., a processor or CPU) 1101 for running software applications and, optionally, an operating system. Read-only memory 1102 and random access memory 1103 store applications and data used by the CPU 1101. Data storage device 1104 provides non-volatile storage for applications and data and may include fixed disk drives, removable disk drives, flash memory devices, and CD-ROMs, DVD-ROMs, or other optical storage devices. Optional user input devices 1106 and 1107 include devices (e.g., a mouse, joystick, camera, touchscreen, and / or microphone) that convey input from one or more users to the computer system 1112.

[0081] The communication or network interface 1108 includes multiple transceivers and allows the computer system 1112 to communicate with other computer systems, networks, or devices via an electronic communication network, including wired and / or wireless communications, and including local area networks or the Internet (e.g., the 802.11 wireless standard). For example, the network interface 1108 may use multiple wireless links to perform multi-link operations (e.g., multi-link packet scheduling and channel access) to improve network throughput. According to embodiments of the invention, the communication or network interface 1108 can operate multiple transceivers simultaneously. The communication or network interface 1108 may also include a multi-band (e.g., dual-band) interface that can operate simultaneously in multiple frequency bands (e.g., 2.4 GHz, 5 GHz, and / or 6 GHz).

[0082] Optional display device 1109 can be any device capable of displaying visual information in response to signals from computer system 1112, and may include, for example, a flat panel touchscreen display, and can be remotely configured. Components of computer system 1112, including CPU 1101, memory 1102 / 1103, data storage 1104, user input device 1106, and graphics subsystem 1105, may be coupled via one or more data buses.

[0083] Some embodiments may be described in the general context of computer-executable instructions (e.g., program modules) that are executed by one or more computers or other devices. Typically, program modules include routines, programs, objects, components, data structures, etc., that perform a particular task or implement a particular abstract data type. Typically, in various embodiments, the functionality of program modules can be combined or distributed as needed.

[0084] Therefore, embodiments of the invention have been described. Although the invention has been described in specific embodiments, it should be understood that the invention should not be construed as limited to such embodiments, but rather as interpreted according to the claims.

Claims

1. A data transmission method for transmitting data triggered based on multiple links in a wireless network, the data transmission method comprising: The first frame is transmitted from the first auxiliary wireless access point of the multi-band wireless access point to the wireless station via the first wireless link, wherein the first frame requests a response frame. It was determined that a second auxiliary wireless access point of the multi-band wireless access point was scheduled to send a second frame to the wireless station via a second wireless link; and The second frame is transmitted from the second auxiliary wireless access point to the wireless station via the second wireless link. The response frame requested by the first frame is scheduled to be transmitted after a predetermined time elapsed from the end of the entity layer conformance protocol data unit containing the second frame.

2. The data transmission method according to claim 1, characterized in that, This predetermined value is determined based on the calculation of aSIFSTime + aSignalExtension – aRxTxTurnaroundTime.

3. The data transmission method according to claim 1, characterized in that, The preset value is 12 μs.

4. The data transmission method according to claim 1, characterized in that, This predetermined value is determined based on the requirements of the wireless access point.

5. The data transmission method according to claim 1, characterized in that, The first wireless link includes a 6 GHz wireless link, and the second wireless link includes a 5 GHz wireless link.

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