[go: up one dir, main page]

WO2025058403A1 - Appareil et procédé de rapport d'erreur rapide dans un système lan sans fil - Google Patents

Appareil et procédé de rapport d'erreur rapide dans un système lan sans fil Download PDF

Info

Publication number
WO2025058403A1
WO2025058403A1 PCT/KR2024/013811 KR2024013811W WO2025058403A1 WO 2025058403 A1 WO2025058403 A1 WO 2025058403A1 KR 2024013811 W KR2024013811 W KR 2024013811W WO 2025058403 A1 WO2025058403 A1 WO 2025058403A1
Authority
WO
WIPO (PCT)
Prior art keywords
frame
error
mpdu
link
sta
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/KR2024/013811
Other languages
English (en)
Korean (ko)
Inventor
김용호
안우진
문주성
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hyundai Motor Co
Kia Corp
Korea National University of Transportation KNUT
Original Assignee
Hyundai Motor Co
Kia Corp
Korea National University of Transportation KNUT
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hyundai Motor Co, Kia Corp, Korea National University of Transportation KNUT filed Critical Hyundai Motor Co
Priority claimed from KR1020240124060A external-priority patent/KR20250038187A/ko
Publication of WO2025058403A1 publication Critical patent/WO2025058403A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
    • H04L69/14—Multichannel or multilink protocols
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/02—Traffic management, e.g. flow control or congestion control
    • H04W28/04—Error control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/10—Small scale networks; Flat hierarchical networks
    • H04W84/12—WLAN [Wireless Local Area Networks]

Definitions

  • the present invention relates to a wireless local area network (WLAN) system. More specifically, it relates to a device and method for rapid error reporting in a wireless LAN system.
  • WLAN wireless local area network
  • Wireless LAN Wireless Local Area Network
  • Wireless LAN technology can be a technology that allows mobile devices such as smart phones, smart pads, laptop computers, portable multimedia players, and embedded devices to wirelessly access the Internet based on wireless communication technology in a short distance.
  • the technology that serves as the background for the invention was written to promote understanding of the background for the invention, and may include content that is not a prior art already known to a person with ordinary skill in the field to which the technology belongs.
  • the present disclosure provides a method and device for detecting and reporting an error in a frame received by an AP (access point) in a wireless LAN system.
  • the present disclosure provides a method and device for a STA (station) to quickly recover a frame in which an error is detected in a wireless LAN system.
  • the present disclosure provides a method and device for an AP and an STA using a STR (simultaneous transmit receive) link pair in a wireless LAN system to report and recover frame errors using multiple links.
  • STR simultaneous transmit receive
  • the present disclosure provides a method and device for identifying a frame for recovering an error frame in a wireless LAN system.
  • the present disclosure provides a method and apparatus for exchanging information for identifying a frame in a wireless LAN system.
  • a method for operation of a station (STA) in a wireless LAN system comprises the steps of: transmitting a plurality of frames in a first link; receiving an error report of a frame in which an error is detected among the plurality of frames in a second link; and transmitting a retransmission frame including the frame in which an error is detected based on the error report, wherein each of the plurality of frames includes a delimiter, and the delimiter includes information for delimiting each of the plurality of frames.
  • a method for operation of an access point (AP) in a wireless LAN system comprises the steps of: receiving a plurality of frames in a first link; detecting an error in at least one frame among the plurality of frames; transmitting an error report based on the frame in which the error is detected; and receiving a retransmission frame transmitted based on the error report, wherein each of the plurality of frames includes a delimiter, and the delimiter includes information for distinguishing each of the plurality of frames.
  • a station in a wireless LAN system, includes a transceiver; and a processor connected to the transceiver, wherein the processor is configured to transmit a plurality of frames in a first link, receive an error report of a frame in which an error is detected among the plurality of frames in a second link, and transmit a retransmission frame including the frame in which an error is detected based on the error report, wherein each of the plurality of frames includes a delimiter, and the delimiter includes information for distinguishing each of the plurality of frames.
  • an access point includes a transceiver; and a processor connected to the transceiver, wherein the processor is configured to receive a plurality of frames in a first link, detect an error in at least one frame among the plurality of frames, transmit an error report based on the frame in which the error is detected, and receive a retransmitted frame transmitted based on the error report, wherein each of the plurality of frames includes a delimiter, and the delimiter includes information for distinguishing each of the plurality of frames.
  • a feedback frame including time information capable of identifying a frame in which an error is detected in a wireless LAN system can be transmitted.
  • an MPDU including previous MPDU and next MPDU information can be transmitted.
  • an AP can identify a frame in which an error is detected and transmit a feedback frame.
  • Figure 1 illustrates a block diagram of a first embodiment of a communication node constituting a wireless LAN system.
  • Figure 2 illustrates a first embodiment of a negotiation procedure for multi-link operation in a wireless LAN system.
  • Figure 3 illustrates a first embodiment of a fast error feedback method.
  • Figure 4a illustrates a second embodiment of a fast error feedback method.
  • Figure 4b illustrates a third embodiment of a fast error feedback method.
  • Figure 5 illustrates a fourth embodiment of a fast error feedback method.
  • Figure 6 illustrates a fifth embodiment of a fast error feedback method.
  • FIG. 7 illustrates a flowchart of an error recovery procedure according to one embodiment of the present disclosure.
  • FIG. 8 illustrates a flowchart of an error reporting procedure according to one embodiment of the present disclosure.
  • first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are only used to distinguish one component from another.
  • the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.
  • the term and/or includes a combination of a plurality of related described items or any item among a plurality of related described items.
  • Figure 1 is a block diagram illustrating a first embodiment of a communication node constituting a wireless LAN system.
  • a communication node may be an access point, a station, an access point (AP), a multi-link device (MLD), or a non-AP MLD.
  • the access point may mean an AP, and the station may mean an STA or a non-AP STA.
  • An operating channel width supported by the access point may be 20 MHz (megahertz), 80 MHz, 160 MHz, etc.
  • An operating channel width supported by the station may be 20 MHz, 80 MHz, etc.
  • the communication node (100) may include at least one processor (110), a memory (120), and a plurality of transceiver devices (130) that are connected to a network and perform communication.
  • the transceiver device (130) may be referred to as a transceiver, an RF (radio frequency) unit, an RF module, etc.
  • the communication node (100) may further include an input interface device (140), an output interface device (150), a storage device (160), etc.
  • Each component included in the communication node (100) may be connected by a bus (170) and perform communication with each other.
  • each component included in the communication node (100) may be connected through an individual interface or individual bus centered around the processor (110), rather than a common bus (170).
  • the processor (110) may be connected to at least one of the memory (120), the transmission/reception device (130), the input interface device (140), the output interface device (150), and the storage device (160) through a dedicated interface.
  • the processor (110) can execute a program command stored in at least one of the memory (120) and the storage device (160).
  • the processor (110) may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which methods according to embodiments of the present invention are performed.
  • Each of the memory (120) and the storage device (160) may be configured with at least one of a volatile storage medium and a nonvolatile storage medium.
  • the memory (120) may be configured with at least one of a read only memory (ROM) and a random access memory (RAM).
  • FIG. 2 is a flowchart illustrating a first embodiment of a negotiation procedure for multi-link operation in a wireless LAN system.
  • the station can detect one or more access points using a passive scanning method or an active scanning method.
  • the station can detect one or more access points by overhearing a beacon frame transmitted by one or more access points.
  • the station can detect one or more access points by transmitting a probe request frame and receiving a probe response frame, which is a response to the probe request frame, from one or more access points.
  • the station can perform an authentication step with the detected access point(s). In this case, the station can perform an authentication step with multiple access points.
  • Authentication algorithms according to the IEEE 802.11 standard can be classified into an open system algorithm that exchanges two authentication frames, a shared key algorithm that exchanges four authentication frames, etc.
  • a station can transmit an authentication request frame based on an authentication algorithm according to the IEEE 802.11 standard, and complete authentication with an access point by receiving an authentication response frame, which is a response to the authentication request frame, from the access point.
  • the station can perform an association step with the access point.
  • the station can select one access point among the access point(s) that performed the authentication step with itself, and perform an association step with the selected access point. That is, the station can transmit an association request frame to the selected access point, and complete the association with the selected access point by receiving an association response frame, which is a response to the association request frame, from the selected access point.
  • An MLD may include one or more STAs associated with the MLD.
  • An MLD may be a logical entity.
  • An MLD may be classified into an AP MLD and a non-AP MLD.
  • Each STA associated with an AP MLD may be an AP, and each STA associated with a non-AP MLD may be a non-AP STA.
  • a multi-link discovery procedure, a multi-link setup procedure, etc. may be performed.
  • the multi-link discovery procedure may be performed in a detection phase between a station and an access point.
  • a ML IE multi-link information element
  • information indicating whether multi-link operation is available and information about available links may be exchanged between an access point (e.g., an AP associated with an MLD) and a station (e.g., a non-AP STA associated with the MLD) in a detection phase.
  • an access point e.g., an AP associated with an MLD
  • a station e.g., a non-AP STA associated with the MLD
  • the access point and/or the station may transmit information about links to be used for the multi-link operation.
  • the negotiation procedure for multi-link operation may be performed in an association procedure (e.g., an association phase) between a station and the access point, and information element(s) required for the multi-link operation may be set or changed by an action frame in the negotiation procedure.
  • the connection procedure between the station and the access point e.g., the association phase
  • available link(s) of the access point can be established, and each link can be assigned an identifier (ID).
  • ID an identifier
  • information indicating whether each link is activated can be transmitted, and the information can be expressed using the link ID.
  • Information indicating whether multi-link operation is available can be transmitted and received in an exchange procedure of a capability information element (e.g., an extremely high throughput (EHT) capability information element) between a station and an access point.
  • the capability information element can include information on a supporting band, information on a supporting link (e.g., an ID and/or number of supporting links), information on links capable of STR operation (e.g., band information of links, spacing information of links), etc.
  • the capability information element can include information individually indicating links capable of STR operation.
  • Figure 3 illustrates a first embodiment of a fast error feedback method.
  • AP MLD 1 and STA MLD 1 may operate in a wireless LAN network.
  • An AP in which AP MLD 1 operates in a first link is AP 1 (301), and an AP in which AP MLD 1 operates in a second link is AP 2 (303). That is, AP 1 (301) and AP 2 (303) may be affiliated to AP MLD 1.
  • an STA in which STA MLD 1 operates in a first link may be STA 1 (311), and an STA in which STA MLD 1 operates in a second link may be STA 2 (313). That is, STA 1 (311) and STA 2 (313) may be affiliated to STA MLD 1.
  • STA Y (320) associated with STA MLD X may operate.
  • X and Y can be natural numbers.
  • STA MLD X may be STA MLD 1 or not STA MLD 1.
  • STA Y (320) may be STA 2 (313) or not STA 2 (313).
  • the first link and the second link of the STA MLD 1 may be links capable of simultaneous transmission and reception (STR link pair).
  • the first link and the second link of the STA MLD 1 may be links capable of simultaneous transmission and reception (NSTR link pair), but may be a conditional STR or conditional NSTR link pair capable of receiving when the AP receives a frame transmitted with strong transmission power or/and low MCS (Modulation and Coding Scheme) on the other link while transmitting on one link.
  • NSTR link pair links capable of simultaneous transmission and reception
  • MCS Modulation and Coding Scheme
  • STA 1 (311) can acquire a TXOP (transmit opportunity) on the first link.
  • TXOP acquisition is acquired when EDCAF of STA 1 (311) determines transmission by channel access procedure (e.g., EDCA backoff operation).
  • STA 1 (311) can transmit a frame (e.g., PPDU (physical layer protocol data unit), MPDU (MAC layer protocol data unit), A-MPDU (aggregated MPDU)) within the TXOP.
  • STA 1 (311) can transmit A-MPDU to AP 1 (301), and multiple MPDUs are included within the A-MPDU.
  • a delimiter that can distinguish MPDUs may be included between MPDUs.
  • a delimiter can be composed of 32 bits and can include at least one of an MPDU length indicator (e.g., 14 bits), a CRC (Cyclic Redundancy Check) (e.g., 8 bits), and a delimiter signature (e.g., 8 bits).
  • MPDU length indicator e.g. 14 bits
  • CRC Cyclic Redundancy Check
  • delimiter signature e.g. 8 bits.
  • MPDU #2 (330) may not be able to transmit data in the queue to an upper layer.
  • MPDU #2 (330) may be a frame that needs to be transmitted to the upper layer urgently. Since MPDU #2 (330) was not properly received, MPDU #2 (330) is not transmitted to the upper layer.
  • AP 2 (303) in the second link may perform a channel access procedure (e.g., an EDCA backoff operation). The channel access procedure may be newly started for AP 2 (303) to transmit the feedback frame (350) for recovering MPDU #2 (330).
  • a channel access procedure e.g., an EDCA backoff operation
  • the channel access procedure that AP 2 (303) was previously performing may be continuously performed.
  • the channel access procedure of AP 2 (303) may succeed (e.g., the EDCA backoff counter reaches 0).
  • AP 2 (303) transmits a feedback frame (350) indicating that MPDU #2 (330) is not properly received to STA 2 (313).
  • the channel access procedure of AP 2 (303) can be performed by AC (access category).
  • the feedback frame (350) can be transmitted by the channel access procedure of any AC (e.g., by the EDCAF of the AC whose channel access procedure is finished the fastest).
  • the feedback frame (350) can be transmitted immediately.
  • the feedback frame (350) may be transmitted by a channel access procedure related to AC of an MPDU of a frame that STA 1 (311) of the first link transmits to AP 1 (301) (e.g., by AC_VO EDCAF of the second link when AC of the MPDU that STA 1 (311) transmits to AP 1 (301) is AC_VO).
  • the AC-specific channel access procedure of AP 2 (303) may end AC_VO before AC_VI and other ACs (e.g., AC_BE and AC_BK).
  • AP 2 (303) may acquire AC_VO TXOP from the second link, and AP 2 (303) transmits a feedback frame (350) to STA 2 (313) indicating that MPDU #2 (330) was not properly received.
  • AP 2 (303) can transmit data frames to STA Y (320).
  • a frame error of the first link can be detected while a frame to be transmitted is generated in the transmission queue of the second link and a channel access procedure is being performed.
  • a frame of an AC to be transmitted in the second link can be generated and a channel access procedure (e.g., a backoff procedure) can be performed, and it can be detected that an MPDU received in the first link has an error before the backoff counter becomes 0.
  • the AC of the MPDU in which an error occurred in the first link can be a different AC from or the same AC as the AC performing the backoff to be transmitted in the second link.
  • a TXOP including a feedback transmission time for the MPDU generated in the first link is set. That is, the duration included in the MAC header of the feedback frame (350) can be set to a time including a data frame transmission time of the AC to be transmitted.
  • the receiving STA of the feedback frame (350) and the data frame can be different.
  • the feedback frame (350) can be transmitted first and then the data frame can be transmitted.
  • the feedback frame (350) and the data frame may be transmitted together in a downlink OFDMA (Orthogonal Frequency Division Multiple Access) manner using different subchannels.
  • OFDMA Orthogonal Frequency Division Multiple Access
  • the feedback may be restricted to be transmitted only when the priority of the AC of the data for which a channel access procedure is performed to be transmitted in the second link is lower than the AC of the MPDU that failed to be transmitted in the first link.
  • the feedback of the MPDU that failed to be transmitted in the first link is higher than any AC. Accordingly, if the channel access for data transmission in the second link is successful regardless of the AC, the feedback frame (350) may be transmitted together with the data transmission.
  • STA MLD 1 can receive the feedback frame (350) of AP MLD 1, and STA MLD 1 can know that MPDU #2 (330) is not properly transmitted in the frame that STA 1 (311) of the first link transmits to AP 1 (301).
  • STA MLD 1 may or may not transmit a response frame (e.g., ACK frame) to the feedback frame (350) of AP MLD 1.
  • STA MLD 1 can retransmit MPDU #2 (330) in the frame that is already being transmitted. For example, MPDU #2 (330) can be retransmitted after MPDU #3 (340), which is the next MPDU after MPDU #2 (330).
  • STA MLD 1 can transmit MPDU #2 (330) to AP 1 (301) through a separate frame.
  • AP MLD 1 If AP MLD 1 normally receives the retransmitted MPDU #2 (330), it can transmit the data in the queue to the upper layer. If an error occurs in the retransmitted MPDU #2 (330) again, the retransmission operation of the MPDU #2 (330) described above can be performed again.
  • STA MLD 1 As another method for STA MLD 1 to perform retransmission, STA 1 (311) of STA MLD 1 can retransmit a frame (e.g., MPDU #3 (340)) transmitted after MPDU #2 (330) instead of retransmitting only MPDU #2 (330). That is, STA 1 (311) can transmit a frame again starting from MPDU #2 (330).
  • a frame e.g., MPDU #3 (340)
  • STA MLD 1 when STA MLD 1 has a conditional NSTR link pair or a conditional STR link pair (e.g., when the first link and the second link are a conditional NSTR link pair), while STA MLD 1 is transmitting a frame to AP MLD 1 on the first link, AP MLD 1 transmits a frame to STA MLD 1 with strong transmission power and/or low MCS on the second link.
  • STA MLD may be able to receive a frame that satisfies a specific condition (e.g.) during frame transmission on one link on the other link.
  • STA MLD may be able to receive a frame that satisfies an MCS less than or equal to a certain value and a reception power greater than or equal to a certain value on the first link on the second link.
  • the feedback frame (350) of the above embodiment may be a frame in various forms.
  • the feedback frame (350) may be one of the control frame including a BlockAck frame, an action frame, and a QoS frame having a control field (e.g., an HT Control field).
  • the feedback frame (350) includes at least one of the Sequence Number (SN) and TID of the MPDU or/and MSDU, information that can identify the MPDU or MSDU (e.g., time information that can identify the MPDU or MSDU, and an MPDU identified by the MPDU order within the A-MPDU).
  • Fig. 4a illustrates a second embodiment of a fast error feedback method.
  • Fig. 4b illustrates a third embodiment of a fast error feedback method.
  • AP MLD 1 and STA MLD 1 may operate in a wireless LAN network.
  • An AP in which AP MLD 1 operates in a first link is AP 1 (401)
  • an AP in which AP MLD 1 operates in a second link is AP 2 (403). That is, AP 1 (401) and AP 2 (403) may be affiliated to AP MLD 1.
  • an STA in which STA MLD 1 operates in a first link may be STA 1 (411)
  • an STA in which STA MLD 1 operates in a second link may be STA 2 (413). That is, STA 1 (411) and STA 2 (413) may be affiliated to STA MLD 1.
  • STA Y (420) associated with STA MLD X may operate.
  • X can be a natural number.
  • Y can be a natural number.
  • STA MLD X may or may not be STA MLD 1.
  • STA Y (420) may or may not be STA 2 (413).
  • the first link and the second link of the STA MLD 1 may be links capable of simultaneous transmission and reception (STR link pair).
  • the first link and the second link of the STA MLD 1 may be links capable of simultaneous transmission and reception (NSTR link pair), but may be a conditional STR or conditional NSTR link pair that can be received when the AP receives a frame transmitted with strong transmission power or/and low MCS (Modulation and Coding Scheme) on the other link while transmitting on one link.
  • NSTR link pair may be links capable of simultaneous transmission and reception
  • MCS Modulation and Coding Scheme
  • STA 1 (411) can acquire a TXOP from the first link. TXOP acquisition is acquired when EDCAF of STA 1 (411) determines transmission by channel access procedure (e.g., EDCA backoff operation). STA 1 (411) can transmit a frame (e.g., PPDU (physical layer protocol data unit), MPDU (MAC layer protocol data unit), A-MPDU (aggregated MPDU)) within the TXOP. STA 1 (411) can transmit A-MPDU to AP 1 (401), and multiple MPDUs are included within the A-MPDU. A delimiter that can distinguish MPDUs may be included between MPDUs.
  • PPDU physical layer protocol data unit
  • MPDU MAC layer protocol data unit
  • A-MPDU aggregated MPDU
  • a delimiter can be composed of 32 bits and can include at least one of an MPDU length indicator (e.g., 14 bits), a CRC (Cyclic Redundancy Check) (e.g., 8 bits), and a delimiter signature (e.g., 8 bits).
  • MPDU length indicator e.g. 14 bits
  • CRC Cyclic Redundancy Check
  • delimiter signature e.g. 8 bits.
  • MPDU #2 (430) Due to MPDU #2 (430) not being properly received, AP 1 (401) may not be able to transmit data in the queue to a higher layer. Alternatively, MPDU #2 (430) may be a frame that must be urgently transmitted to a higher layer. Because MPDU #2 (430) was not received properly, MPDU #2 (430) is not transmitted to the upper layer.
  • AP MLD 1 is transmitting a frame to STA Y (420) on the second link while receiving a frame from STA 1 (411) on the first link. That is, AP MLD 1 is already transmitting a frame within the TXOP that AP MLD 1 acquired on the second link.
  • AP 2 (403) of AP MLD 1 may stop transmitting a frame (460) that it was transmitting to STA Y (420) in order to transmit a feedback frame (450) indicating that MPDU #2 (430) was not properly received by STA 2 (413).
  • the frame (460) transmitted to STA Y (420) may include an indicator (e.g., CS required) indicating that STA Y (420) must perform channel sensing (CS) before transmitting a response frame (e.g., BlockAck frame) to AP 2 (403) and transmit the response frame only when the channel is idle for a certain period of time as a result of channel sensing.
  • the frame (460) transmitted to STA Y (420) may include a Long or Short channel sensing time indicator.
  • the Long or Short channel sensing time indicator may be included only when a channel sensing request indicator is included.
  • the Long channel sensing indicator indicates to perform channel sensing for the PIFS time
  • the Short channel sensing indicator indicates to perform channel sensing for the SIFS time.
  • the channel sensing time indicator when the channel sensing time indicator is set, it may be interpreted as the Long channel sensing indicator, and when the channel sensing time indicator is not set, it may be interpreted as the Short channel sensing indicator.
  • the channel sensing request indicator if the channel sensing request indicator is included, it may be considered that the Long channel sensing indicator is included, which indicates channel sensing during the PIFS time rather than the SIFS time, without including the channel time sensing indicator.
  • the channel sensing request indicator (CS required) may be included in the MAC header.
  • the channel sensing time indicator may not be included, and if the channel sensing request indicator is included, the STA that has received it transmits a response frame only when the channel is idle after performing channel sensing during the SIFS time.
  • the frame transmission that AP 2 (403) was transmitting to STA Y (420) may be stopped in MPDU units.
  • a frame that AP 2 (403) intends to transmit to STA Y (420) may include MPDU #A, MPDU #B, and MPDU #C, and the frame transmission may be stopped after MPDU #A and MPDU #B are completely transmitted. That is, MPDU #A and MPDU #B are not lost.
  • the frame (460) that AP 2 (403) was transmitting to STA Y (420) may be immediately stopped.
  • a frame that AP 2 (403) intends to transmit to STA Y (420) may include MPDU #A, MPDU #B, and MPDU #C, and frame transmission may be stopped while MPDU #A is being transmitted and MPDU #B is being transmitted. In this case, MPDU #A is not lost, but MPDU #B is lost.
  • the transmission stoppage may be determined by considering the importance of the transmitted MPDU (e.g., priority of AC, delay bound).
  • the transmission may be stopped immediately even if a loss occurs.
  • the transmission stoppage may be determined by considering the delay bound of the transmitted frame. Even if the frame transmitted on the second link is immediately stopped and retransmitted, if the delay limit can be met, the transmission can be stopped immediately.
  • AP 2 (403) stops frame transmission, and after a certain period of time (e.g., SIFS (short interframe space) or RIFS (reduced interframe space)), AP 2 (403) can transmit a feedback frame (450) to STA 2 (413) indicating that MPDU #2 (430) is not properly received.
  • SIFS short interframe space
  • RIFS reduced interframe space
  • the feedback frame (450) can be transmitted using an OFDMA (Orthogonal Frequency Division Multiple Access) scheme.
  • OFDMA Orthogonal Frequency Division Multiple Access
  • a feedback frame (450) whose receiver is STA 2 (413) and a data frame whose receiver is STA Y (420) can be transmitted together using different subchannels using an OFDMA scheme.
  • STA Y (420) performs channel sensing and transmits a response frame to AP 2 (403) when the data frame being received from AP 2 (403) has been terminated and the received data frame includes a channel sensing request indicator.
  • the response frame is not transmitted after a certain period of time (e.g., SIFS or PIFS).
  • STA Y (420) Since AP 2 (403) transmits a feedback frame (450) to STA 2 (413) after a certain period of time (e.g., RIFS or SIFS), STA Y (420) does not transmit a response frame to AP 2 (403). After transmitting the feedback frame (450) to STA 2 (413), AP 2 (403) can transmit a data frame to STA Y (420) again, and STA Y (420) transmits a response frame to AP 2 (403). STA MLD 1 can receive the feedback frame (450) of AP MLD 1, and STA MLD 1 can know that MPDU #2 (430) is not transmitted properly in the frame that STA 1 (411) of the first link transmits to AP 1 (401).
  • a certain period of time e.g., RIFS or SIFS
  • STA MLD 1 may or may not transmit a response frame (e.g., an ACK frame) to the feedback frame (450) of AP MLD 1.
  • STA MLD 1 may retransmit MPDU #2 (430) in a frame that is already being transmitted. For example, MPDU #2 (430) may be retransmitted after MPDU #3 (440), which is the next MPDU after MPDU #2 (430).
  • STA MLD 1 may transmit MPDU #2 (430) to AP 1 (401) through a separate frame. If AP MLD 1 normally receives the retransmitted MPDU #2 (430), it may transmit the data in the queue to the upper layer.
  • STA 1 (411) of STA MLD 1 can retransmit a frame transmitted after MPDU #2 (430) (e.g., MPDU #3 (440)) together with MPDU #2 (430), instead of retransmitting only MPDU #2 (430). That is, STA 1 (411) can transmit a frame again starting from MPDU #2 (430).
  • STA MLD 1 has a conditional NSTR link pair or a conditional STR link pair (e.g., if the first link and the second link are a conditional NSTR link pair), while STA MLD 1 is transmitting a frame to AP MLD 1 on the first link, AP MLD 1 transmits a frame to STA MLD 1 with strong transmission power and/or low MCS on the second link.
  • STA MLD may be able to receive a frame satisfying a specific condition on the other link during frame transmission on one link. For example, STA MLD may be able to receive a frame satisfying an MCS less than or equal to a certain value and a reception power greater than or equal to a certain value on the first link on the second link.
  • the feedback frame (450) of the above embodiment may be a frame of various forms.
  • the feedback frame (450) may be one of a control frame including a BlockAck frame, an action frame, and a QoS frame having a control field (e.g., an HT Control field).
  • the feedback frame (450) includes at least one of a Sequence Number (SN) and TID of an MPDU or/and an MSDU, information that can identify an MPDU or an MSDU (e.g., time information that can identify an MPDU or an MSDU, an MPDU identified by the MPDU order within an A-MPDU).
  • AP MLD 1 when AP MLD 1 receives a frame of STA MLD 1 in the first link, it may transmit an MU-RTS frame as the first frame of the TXOP of the second link for smooth transmission of the feedback frame (450).
  • the MU-RTS frame may indicate STAs to be communicated with within the TXOP.
  • AP MLD 1 may indicate AIDs to be communicated with within the TXOP.
  • the AIDs included in the MU-RTS frame when the communication target STAs are MLD 1 and MLD X, the AIDs included in the MU-RTS frame indicate STA MLD 1 and STA MLD X.
  • the AID of STA MLD X may be identical to the AID of STA Y (420).
  • STA MLD 1 and STA MLD X can receive MU-RTS frames on the second link, and simultaneously transmit CTS frames (e.g., simultaneous CTS frames) after a certain period of time (e.g., SIFS time) after receiving MU-RTS on the second link.
  • CTS frames e.g., simultaneous CTS frames
  • AP MLD 1 transmits a data frame to STA Y (420) on the second link after receiving the CTS frame on the second link.
  • AP 2 (403) of AP MLD 1 can stop transmitting frames to STA Y (420) in order to transmit a feedback frame (450) indicating that MPDU #2 (430) has not been properly received by STA 2 (413).
  • the frame (460) transmitted to STA Y (420) may include an indicator (e.g., CS required) indicating that STA Y (420) must perform channel sensing (CS) before transmitting a response frame (e.g., BlockAck frame) to AP 2 (403) and transmit the response frame only when the channel is idle for a certain period of time as a result of channel sensing.
  • the frame (460) transmitted to STA Y (420) may include a Long or Short channel sensing time indicator.
  • the Long or Short channel sensing time indicator may be included only when a channel sensing request indicator is included.
  • the Long channel sensing indicator indicates to perform channel sensing for the PIFS time
  • the Short channel sensing indicator indicates to perform channel sensing for the SIFS time.
  • the channel sensing time indicator may be interpreted as the Long channel sensing indicator, and if the channel sensing time indicator is not set, it may be interpreted as the Short channel sensing indicator.
  • the channel sensing request indicator it may be considered that the Long channel sensing indicator is included, which indicates channel sensing during the PIFS time rather than the SIFS time, without including the channel time sensing indicator.
  • the channel sensing request indicator (CS required) may be included in the MAC header.
  • the channel sensing time indicator may not be included, and if the channel sensing request indicator is included, the STA that has received it transmits a response frame only when the channel is idle after performing channel sensing during the SIFS time.
  • Transmission of the frame (460) that AP 2 (403) was transmitting to STA Y (420) may be stopped in MPDU units.
  • a frame that AP 2 (403) intends to transmit to STA Y (420) may include MPDU #A, MPDU #B, and MPDU #C, and frame transmission may be stopped after MPDU #A and MPDU #B are completely transmitted. That is, MPDU #A and MPDU #B are not lost.
  • the transmission of the frame (460) that AP 2 (403) was transmitting to STA Y (420) may be stopped immediately.
  • the frame that AP 2 (403) is to transmit to STA Y (420) may include MPDU #A, MPDU #B, and MPDU #C, and the frame transmission may be stopped while MPDU #A is being transmitted and MPDU #B is being transmitted. In this case, MPDU #A is not lost, but MPDU #B is lost.
  • the transmission stoppage may be determined by considering the importance of the transmitted MPDU (e.g., priority of AC, delay bound).
  • the transmission may be stopped immediately even if a loss occurs.
  • the transmission stoppage may be determined by considering the delay bound of the transmitted frame. Even if the frame transmitted on the second link is immediately stopped and retransmitted, if the delay limit can be met, the transmission can be stopped immediately.
  • AP 2 (403) stops frame transmission, and after a certain period of time (e.g., SIFS (short interframe space) or RIFS (reduced interframe space)), AP 2 (403) can transmit a feedback frame (450) to STA 2 (413) indicating that MPDU #2 (430) is not properly received.
  • SIFS short interframe space
  • RIFS reduced interframe space
  • the feedback frame (450) can be transmitted in an OFDMA (Orthogonal Frequency Division Multiple Access) manner.
  • a feedback frame (450) whose receiver is STA 2 (413) and a data frame whose receiver is STA Y (420) can be transmitted together in an OFDMA manner.
  • STA Y (420) performs channel sensing and transmits a response frame to AP 2 (403) when the data frame being received from AP 2 (403) has ended transmission and the received data frame includes a channel sensing request indicator.
  • While performing channel sensing if the channel is busy due to a frame transmitted by AP 2 (403) (e.g., a feedback frame (450)), the response frame is not transmitted after a certain period of time (e.g., SIFS or PIFS). Since AP 2 (403) transmits the feedback frame (450) to STA 2 (413) after a certain period of time (e.g., RIFS or SIFS), STA Y (420) does not transmit a response frame to AP 2 (403). AP 2 (403) may transmit a feedback frame (450) to STA 2 (413) and then transmit a data frame to STA Y (420), and STA Y (420) may transmit a response frame to AP 2 (403).
  • a certain period of time e.g., SIFS or PIFS
  • STA MLD 1 may receive the feedback frame (450) of AP MLD 1, and STA MLD 1 may recognize that MPDU #2 (430) is not properly transmitted in the frame transmitted by STA 1 (411) of the first link to AP 1 (401).
  • STA MLD 1 may or may not transmit a response frame (e.g., an ACK frame) to the feedback frame (450) of AP MLD 1.
  • STA MLD 1 may retransmit MPDU #2 (430) in the frame that is already being transmitted. For example, MPDU #2 (430) can be retransmitted after MPDU #3 (440), which is the next MPDU after MPDU #2 (430).
  • STA MLD 1 can transmit MPDU #2 (430) to AP 1 (401) through a separate frame.
  • AP MLD 1 If AP MLD 1 normally receives the retransmitted MPDU #2 (430), it can transmit the data in the queue to the upper layer. If the retransmitted MPDU #2 (430) causes an error again, the retransmission operation of MPDU #2 (430) described above can be performed again.
  • STA MLD 1 performs retransmission
  • STA 1 (411) of STA MLD 1 can retransmit a frame (e.g., MPDU #3 (440)) transmitted after MPDU #2 (430) together with MPDU #2 (430), instead of retransmitting only MPDU #2 (430). That is, STA 1 (411) can transmit frames again starting from MPDU #2 (430).
  • a frame e.g., MPDU #3 (440)
  • STA MLD 1 has a conditional NSTR link pair or a conditional STR link pair (e.g., if the first link and the second link are a conditional NSTR link pair), while STA MLD 1 is transmitting a frame to AP MLD 1 on the first link, AP MLD 1 transmits a frame to STA MLD 1 with strong transmission power and/or low MCS on the second link.
  • STA MLD may be able to receive a frame satisfying a specific condition on the other link during frame transmission on one link. For example, STA MLD may be able to receive a frame satisfying an MCS less than or equal to a certain value and a reception power greater than or equal to a certain value on the first link on the second link.
  • the feedback frame (450) of the above embodiment may be a frame of various forms.
  • the feedback frame (450) may be one of a control frame including a BlockAck frame, an action frame, and a QoS frame having a control field (e.g., an HT Control field).
  • the feedback frame (450) includes at least one of a Sequence Number (SN) and TID of an MPDU or/and an MSDU, information that can identify an MPDU or an MSDU (e.g., time information that can identify an MPDU or an MSDU, an MPDU identified by the MPDU order within an A-MPDU).
  • Figure 5 illustrates a fourth embodiment of a fast error feedback method.
  • AP MLD 1 and STA MLD 1 may operate in a wireless LAN network.
  • An AP in which AP MLD 1 operates in a first link is AP 1 (501)
  • an AP in which AP MLD 1 operates in a second link is AP 2 (503). That is, AP 1 (501) and AP 2 (503) may be affiliated to AP MLD 1.
  • an STA in which STA MLD 1 operates in a first link may be STA 1 (511)
  • an STA in which STA MLD 1 operates in a second link may be STA 2 (513). That is, STA 1 (511) and STA 2 (513) may be affiliated to STA MLD 1.
  • STA Y (520) associated with STA MLD X may operate.
  • X can be a natural number.
  • Y can be a natural number.
  • STA MLD X may or may not be STA MLD 1.
  • STA Y (520) may or may not be STA 2 (513).
  • the first link and the second link of the STA MLD 1 may be links capable of simultaneous transmission and reception (STR link pair).
  • the first link and the second link of the STA MLD 1 may be links capable of simultaneous transmission and reception (NSTR link pair), but may be a conditional STR or conditional NSTR link pair capable of receiving when the AP receives a frame with strong transmission power or/and low MCS (Modulation and Coding Scheme) on the other link while transmitting on one link.
  • NSTR link pair links capable of simultaneous transmission and reception
  • MCS Modulation and Coding Scheme
  • STA 1 (511) can acquire a TXOP from the first link. TXOP acquisition is acquired when EDCAF of STA 1 (511) determines transmission by channel access procedure (e.g., EDCA backoff operation). STA 1 (511) can transmit a frame (e.g., PPDU (physical layer protocol data unit), MPDU (MAC layer protocol data unit), A-MPDU (aggregated MPDU)) within the TXOP. STA 1 (511) can transmit A-MPDU to AP 1 (501), and multiple MPDUs are included within the A-MPDU. A delimiter that can distinguish MPDUs may be included between MPDUs.
  • PPDU physical layer protocol data unit
  • MPDU MAC layer protocol data unit
  • A-MPDU aggregated MPDU
  • a delimiter can be composed of 32 bits and can include at least one of an MPDU length indicator (e.g., 14 bits), a CRC (Cyclic Redundancy Check) (e.g., 8 bits), and a delimiter signature (e.g., 8 bits).
  • MPDU length indicator e.g. 14 bits
  • CRC Cyclic Redundancy Check
  • delimiter signature e.g. 8 bits.
  • MPDU #2 (530) may be a frame that must be urgently transmitted to a higher layer. Since MPDU #2 (530) was not properly received, MPDU #2 (530) is not transmitted to the upper layer. Since AP 2 (503) did not properly receive MPDU #2 (530), it cannot know information about MPDU #2 (530). For example, AP 2 (503) cannot know the TID and SN of MPDU #2 (530).
  • All MPDUs of a frame that STA 1 (511) transmits to AP 1 (501) may be MPDUs having the same TID.
  • all TIDs of the MPDUs may be TID A.
  • AP MLD 1 may know that MPDU #2 (530) was not received in the frame being received from STA 1 (511) on the first link after completing decoding MPDU #3 (540).
  • a feedback frame (550) for indicating that MPDU #2 (530) was not properly received may be transmitted after completing reception of MPDU #3 (540).
  • the MPDUs of a frame that STA 1 (511) transmits to AP 1 (501) may be MPDUs having different TIDs.
  • MPDU #2 (530) may be TID A
  • MPDU #2 (530) may be TID B
  • MPDU #2 (530) may be an MPDU that must be transmitted urgently and may be transmitted among MPDUs having different TIDs. Since MPDU #2 (530) has a different TID from other MPDUs, AP MLD 1 may not know that MPDU #2 (530) was not received in the frame being received from STA 1 (511) on the first link after completing decoding MPDU #3 (540). Alternatively, all MPDUs of the frame that STA 1 (511) transmits to AP 1 (501) may have the same TID, but the SN order of the MPDUs may not be transmitted consistently.
  • the SNs of MPDU #1, MPDU #2 (530), and MPDU #3 (540) may be 1, 3, and 2. Therefore, if MPDU #2 (530) is not received, AP MLD 1 may not know whether MPDU #2 (530) should be retransmitted.
  • STA 1 (511) may include at least one of the SN (sequence number), TID information, and whether rapid recovery is required of a previous or/and next MPDU in the MAC header or/and the A-MPDU delimiter of the frame transmitted to AP 1 (501). That is, STA 1 includes information capable of identifying the previous or/and next MPDU in each frame or/and the A-MPDU delimiter transmitted to AP 1. In this case, if AP 1 (501) correctly received MPDU #1 and did not correctly receive MPDU #2 (530), AP 1 (501) can immediately know information (e.g., TID, SN) about MPDU #2 (530) in which an error occurred. If STA 1 (511) indicates that MPDU #2 (530) requires rapid recovery, AP 1 (501) may request retransmission of MPDU #2 (530).
  • the SN sequence number
  • TID information e.g., whether rapid recovery is required of a previous or/and next MPDU in the MAC header or/and the A-MP
  • AP 2 (503) in the second link may perform a channel access procedure (e.g., an EDCA backoff operation).
  • the channel access procedure may be newly started for AP 2 (503) to transmit a feedback frame (550) for recovering MPDU #2 (530).
  • the channel access procedure that AP 2 (503) was previously performing may be continuously performed.
  • the channel access procedure of AP 2 (503) may succeed (e.g., the EDCA backoff counter reaches 0).
  • AP 2 (503) transmits a feedback frame (550) to STA 2 (513) indicating that MPDU #2 (530) was not properly received.
  • the channel access procedure of AP 2 (503) may be performed per AC (access category).
  • the feedback frame (550) may be transmitted by any AC's channel access procedure (e.g., by EDCAF of AC whose channel access procedure ends the fastest).
  • EDCAF of AC whose channel access procedure ends the fastest.
  • the feedback frame (550) may be transmitted immediately.
  • the feedback frame (550) may be transmitted by a channel access procedure related to AC of MPDU of a frame that STA 1 (511) of the first link transmits to AP 1 (501) (e.g., if AC of MPDU that STA 1 (511) transmits to AP 1 (501) is AC_VO, by AC_VO EDCAF of the second link).
  • the AC-specific channel access procedure of AP 2 (503) may terminate AC_VO before AC_VI and other ACs (e.g., AC_BE and AC_BK).
  • AP 2 (503) may acquire AC_VO TXOP from the second link, and AP 2 (503) may transmit a feedback frame (550) to STA 2 (513) indicating that MPDU #2 (530) was not properly received. In the remaining AC_VO TXOP of AP 2 (503), AP 2 (503) may transmit a data frame to STA Y (520).
  • a frame error of the first link can be detected while a frame to be transmitted is generated in the transmission queue of the second link and a channel access procedure is being performed.
  • a frame of an AC to be transmitted in the second link can be generated and a channel access procedure (e.g., a backoff procedure) can be performed, and it can be detected that an MPDU received in the first link has an error before the backoff counter becomes 0.
  • the AC of the MPDU in which an error occurred in the first link can be a different AC from or the same AC as the AC performing the backoff to be transmitted in the second link.
  • a TXOP including a feedback transmission time for the MPDU generated in the first link is set. That is, the duration included in the MAC header of the feedback frame (550) can be set to a time including a data frame transmission time of the AC to be transmitted.
  • the receiving STA of the feedback frame (550) and the data frame can be different.
  • the feedback frame (550) can be transmitted first and then the data frame can be transmitted.
  • the feedback frame (550) and the data frame may be transmitted together in a downlink OFDMA (Orthogonal Frequency Division Multiple Access) manner using different subchannels.
  • OFDMA Orthogonal Frequency Division Multiple Access
  • the feedback may be restricted to be transmitted only when the priority of the AC of the data for which a channel access procedure is performed to be transmitted in the second link is lower than the AC of the MPDU that failed to be transmitted in the first link.
  • the feedback of the MPDU that failed to be transmitted in the first link is higher than any AC. Accordingly, if the channel access for data transmission in the second link is successful regardless of the AC, the feedback frame (550) may be transmitted together with the data transmission.
  • STA MLD 1 can receive the feedback frame (550) of AP MLD 1, and STA MLD 1 can know that MPDU #2 (530) is not properly transmitted in the frame that STA 1 (511) of the first link transmits to AP 1 (501).
  • STA MLD 1 may or may not transmit a response frame (e.g., an ACK frame) to the feedback frame (550) of AP MLD 1.
  • STA MLD 1 can retransmit MPDU #2 (530) in the frame that is already being transmitted. For example, MPDU #2 (530) can be retransmitted after MPDU #3 (540), which is the next MPDU after MPDU #2 (530).
  • STA MLD 1 can transmit MPDU #2 (530) to AP 1 (501) through a separate frame.
  • AP MLD 1 If AP MLD 1 normally receives the retransmitted MPDU #2 (530), it can transmit the data in the queue to the upper layer. If an error occurs in the retransmitted MPDU #2 (530) again, the retransmission operation of the MPDU #2 (530) described above can be performed again.
  • STA MLD 1 As another method for STA MLD 1 to perform retransmission, STA 1 (511) of STA MLD 1 can retransmit a frame (e.g., MPDU #3 (540)) transmitted after MPDU #2 (530) instead of retransmitting only MPDU #2 (530). That is, STA 1 (511) can transmit a frame again starting from MPDU #2 (530).
  • a frame e.g., MPDU #3 (540)
  • STA MLD 1 has a conditional NSTR link pair or a conditional STR link pair (e.g., if the first link and the second link are a conditional NSTR link pair), while STA MLD 1 is transmitting a frame to AP MLD 1 on the first link, AP MLD 1 transmits a frame with strong transmission power and/or low MCS on the second link to STA MLD 1.
  • the STA MLD may be able to receive a frame satisfying a specific condition during frame transmission on one link on the other link. For example, the STA MLD may be able to receive a frame satisfying an MCS less than or equal to a certain value and a reception power greater than or equal to a certain value on the first link on the second link.
  • the feedback frame (550) of the above embodiment may be a frame of various forms.
  • the feedback frame (550) may be one of a control frame including a BlockAck frame, an action frame, and a QoS frame having a control field (e.g., an HT Control field).
  • the feedback frame (550) includes at least one of a Sequence Number (SN) and a TID of an MPDU or/and an MSDU, information that can identify an MPDU or an MSDU (e.g., time information that can identify an MPDU or an MSDU, an MPDU identified by the MPDU order within an A-MPDU).
  • Figure 6 illustrates a fifth embodiment of a fast error feedback method.
  • AP MLD 1 and STA MLD 1 may operate in a wireless LAN network.
  • An AP in which AP MLD 1 operates in a first link is AP 1 (601), and an AP in which AP MLD 1 operates in a second link is AP 2 (603). That is, AP 1 (601) and AP 2 (603) may be affiliated to AP MLD 1.
  • an STA in which STA MLD 1 operates in a first link may be STA 1 (611), and an STA in which STA MLD 1 operates in a second link may be STA 2 (613). That is, STA 1 (611) and STA 2 (613) may be affiliated to STA MLD 1.
  • STA Y associated with STA MLD X may operate.
  • X may be a natural number.
  • Y can be a natural number.
  • STA MLD X can be STA MLD 1 or not STA MLD 1.
  • STA Y can be STA 2 (613) or not STA 2 (613).
  • the first link and the second link of the STA MLD 1 can be links capable of simultaneous transmission and reception (STR link pair).
  • the first link and the second link of the STA MLD 1 can be links capable of simultaneous transmission and reception (NSTR link pair), but can be a conditional STR or conditional NSTR link pair that can be received when the AP receives a frame transmitted with strong transmission power or/and low MCS (Modulation and Coding Scheme) on the other link while transmitting on one link.
  • NSTR link pair can be links capable of simultaneous transmission and reception
  • MCS Modulation and Coding Scheme
  • STA 1 (611) can acquire a TXOP from the first link. TXOP acquisition is acquired when EDCAF of STA 1 (611) determines transmission by channel access procedure (e.g., EDCA backoff operation). STA 1 (611) can transmit a frame (e.g., PPDU (physical layer protocol data unit), MPDU (MAC layer protocol data unit), A-MPDU (aggregated MPDU)) within the TXOP. STA 1 (611) can transmit A-MPDU to AP 1 (601), and multiple MPDUs are included within the A-MPDU. A delimiter that can distinguish MPDUs may be included between MPDUs.
  • PPDU physical layer protocol data unit
  • MPDU MAC layer protocol data unit
  • A-MPDU aggregated MPDU
  • a delimiter can be composed of 32 bits and can include at least one of an MPDU length indicator (e.g., 14 bits), a CRC (Cyclic Redundancy Check) (e.g., 8 bits), and a delimiter signature (e.g., 8 bits).
  • MPDU length indicator e.g. 14 bits
  • CRC Cyclic Redundancy Check
  • delimiter signature e.g. 8 bits.
  • MPDU #2 (630) may not be able to transmit data in the queue to a higher layer.
  • MPDU #2 (630) may be a frame that must be urgently transmitted to a higher layer. Since MPDU #2 (630) was not properly received, MPDU #2 (630) is not transmitted to the upper layer. Since AP 2 (603) did not properly receive MPDU #2 (630), it cannot know information about MPDU #2 (630). For example, AP 2 (603) cannot know the TID and SN of MPDU #2 (630).
  • All MPDUs of a frame that STA 1 (611) transmits to AP 1 (601) may be MPDUs having the same TID.
  • all TIDs of the MPDUs may be TID A.
  • AP MLD 1 may know that MPDU #2 (630) was not received in the frame being received from STA 1 (611) on the first link after completing decoding MPDU #3 (640).
  • a feedback frame (650) for indicating that MPDU #2 (630) was not properly received may be transmitted after completing reception of MPDU #3 (640).
  • the MPDUs of a frame that STA 1 (611) transmits to AP 1 (601) may be MPDUs having different TIDs.
  • MPDU #2 (630) may be TID A
  • MPDU #2 (630) may be TID B
  • MPDU #2 (630) may be an MPDU that must be transmitted urgently and may be transmitted among MPDUs having different TIDs. Since MPDU #2 (630) has a different TID from other MPDUs, AP MLD 1 may not know that MPDU #2 (630) was not received in the frame being received from STA 1 (611) on the first link after completing decoding MPDU #3 (640). Alternatively, all MPDUs of the frame that STA 1 (611) transmits to AP 1 (601) may have the same TID, but the SN order of the MPDUs may not be transmitted consistently.
  • the SNs of MPDU #1, MPDU #2 (630), and MPDU #3 (640) may be 1, 3, and 2. Therefore, if MPDU #2 (630) is not received, AP MLD 1 may not know whether MPDU #2 (630) should be retransmitted.
  • AP 2 (603) cannot know the information of MPDU #2 (630), but it can know the time of occurrence of an error.
  • the occurrence of an error can be known when, after successfully receiving the delimiter for MPDU #1 or MPDU #2 (630), only energy is detected but not decoded, and then the delimiter transmitted before transmitting MPDU #3 (640) is received.
  • AP 2 (603) can perform a channel access procedure (e.g., EDCA backoff operation) on the second link.
  • the channel access procedure can be newly started for AP 2 (603) to transmit the feedback frame (650) for recovering MPDU #2 (630).
  • the AC-specific channel access procedure of AP 2 may end AC_VO before AC_VI and other ACs (e.g., AC_BE and AC_BK).
  • AP 2 (603) may acquire AC_VO TXOP from the second link, and AP 2 (603) transmits a feedback frame (650) to STA 2 (613) indicating that MPDU #2 (630) was not properly received.
  • AP 2 (603) can transmit data frames to STA Y.
  • a frame error of the first link can be detected while a frame to be transmitted is generated in the transmission queue of the second link and a channel access procedure is being performed.
  • a frame of an AC to be transmitted in the second link can be generated and a channel access procedure (e.g., a backoff procedure) can be performed, and it can be detected that an MPDU received in the first link has an error before the backoff counter becomes 0.
  • the AC of the MPDU in which an error occurred in the first link can be a different AC from or the same AC as the AC performing the backoff to be transmitted in the second link.
  • Information indicating that MPDU #2 (630) is not properly received may be indicated as time information.
  • the time information is information including at least one of 'TSF (time synchronization function) information', 'TSF information and offset', 'time interval using multiple TSF information', and 'frame duration'.
  • 'TSF time synchronization function
  • the time information may indicate 'the start or end time of the last properly received MPDU', 'the start or end time of the MPDU in which an error occurred', or 'the time during which the MPDU in which an error occurred is being transmitted'.
  • the time information may be indicated as TSF information that can identify that there is an error in MPDU #2 (630).
  • the TSF information indicated by AP MLD 1 may be based on the TSF of the first link or the second link.
  • the TSF information indicated by AP MLD 1 may be indicated using some bits (e.g., some LSBs) of the TSF managed by AP MLD 1.
  • the time information may indicate at least one of 'the transmission interval of the last well-received MPDU' and 'the transmission interval of the MPDU in which an error occurred'.
  • the time information may be indicated as TSF information and an offset that can identify that there is an error in MPDU #2 (630).
  • the offset information is time information indicating a time after or before a time indicated by the TSF information.
  • the offset information may indicate a time length in a manner identical to or similar to a duration field included in the MAC header of the MPDU.
  • the TSF information indicated by AP MLD 1 may be based on the TSF of the first link or the second link.
  • the time information may indicate at least one of 'the transmission interval of the last well-received MPDU' and 'the transmission interval of the MPDU in which an error occurred'.
  • the time information may be indicated by a plurality of TSF information that can identify that there is an error in MPDU #2 (630).
  • the plurality of TSF information indicated by AP MLD 1 may be based on the TSF of the first link or the second link. Some or all of the plurality of TSF information indicated by AP MLD 1 may be indicated using some bits (e.g., some LSBs) of the TSF managed by AP MLD 1.
  • the time information may indicate at least one of 'transmission length of the last well-received MPDU' and 'transmission length of the MPDU in which an error occurred'.
  • the time information may be indicated by duration information that can identify that there is an error in MPDU #2 (630).
  • the duration of the frame may indicate the time length in a manner identical to or similar to the duration field included in the MAC header of the MPDU.
  • STA MLD 1 must record timing information (e.g., TSF information when transmitting each MPDU, duration information of each MPDU) during transmission of each MPDU in order to correctly recover corrupted MPDUs (e.g., MPDU #2 (630)).
  • AP MLD 1 must record timing information (e.g., TSF information when receiving each MPDU, duration information of each MPDU) during reception of each MPDU in order to correctly recover corrupted MPDUs (e.g., MPDU #2 (630)).
  • STA MLD 1 can receive the feedback frame (650) of AP MLD 1, and STA MLD 1 can identify that MPDU #2 (630) was not properly transmitted using the time information of the feedback frame (650) of AP MLD 1.
  • STA MLD 1 may or may not transmit a response frame (e.g., an ACK frame) to the feedback frame (650) of AP MLD 1.
  • STA MLD 1 can retransmit MPDU #2 (630), which is an MPDU in which an error occurred, in a frame that is already being transmitted. For example, MPDU #2 (630) can be retransmitted after MPDU #3 (640), which is the next MPDU after MPDU #2 (630).
  • STA MLD 1 can transmit MPDU #2 (630) to AP 1 (601) through a separate frame. If AP MLD 1 receives the retransmitted MPDU #2 (630) without error, it can transmit the data in the queue to the upper layer. If the retransmitted MPDU #2 (630) causes an error again, the retransmission operation of the MPDU #2 (630) described above can be performed again.
  • STA 1 (611) of STA MLD 1 can retransmit a frame (e.g., MPDU #3 (640)) transmitted after MPDU #2 (630) instead of retransmitting only MPDU #2 (630). That is, STA 1 (611) can transmit the frame again starting from MPDU #2 (630).
  • a frame e.g., MPDU #3 (640)
  • STA MLD 1 has a conditional NSTR link pair or a conditional STR link pair (e.g., if the first link and the second link are a conditional NSTR link pair), while STA MLD 1 is transmitting a frame to AP MLD 1 on the first link, AP MLD 1 transmits a frame to STA MLD 1 with strong transmission power and/or low MCS on the second link.
  • STA MLD may be able to receive a frame satisfying a specific condition during frame transmission on one link on the other. For example, STA MLD may be able to receive a frame satisfying an MCS less than or equal to a certain value and a reception power greater than or equal to a certain value on the first link on the second link.
  • the feedback frame (650) of the above embodiment may be a frame of various forms.
  • the feedback frame (650) may be one of a control frame including a BlockAck frame, an action frame, and a QoS frame having a control field (e.g., an HT Control field).
  • the feedback frame (650) includes at least one of a Sequence Number (SN) and a TID of an MPDU or/and an MSDU, information that can identify an MPDU or an MSDU (e.g., time information that can identify an MPDU or an MSDU, an MPDU identified by the MPDU order within an A-MPDU).
  • the described procedure is performed by a first STA and an AP.
  • the first STA and the AP may be connected using a first link and a second link.
  • the first link and the second link may be a STR link pair.
  • the AP may be connected to a second STA using the second link. That is, the first STA, the second STA, and the AP may be multi-link devices (MLDs).
  • MLDs multi-link devices
  • FIG. 7 is a flowchart illustrating an error recovery procedure according to an embodiment of the present disclosure.
  • FIG. 7 illustrates a procedure performed by a first STA.
  • a first STA e.g., STA MLD 1 of FIG. 3
  • AP e.g., AP MLD 1 of FIG. 3
  • a first STA transmits a plurality of frames (e.g., MPDU #2 (330) and MPDU #3 (340) of FIG. 3) on a first link.
  • the plurality of frames may include at least one MPDU.
  • Each frame may include a delimiter for distinguishing the frames.
  • the delimiter may include at least one of an MPDU length indicator, a CRC, or a delimiter signature.
  • the delimiter may have a size of 32 bits.
  • the delimiter includes at least one of an MPDU including the delimiter or an SN (sequence number) of an MPDU to be transmitted next, TID information, or whether rapid recovery is required, for a receiver to detect an error.
  • the first STA receives an error report from the second link.
  • the error report includes a message transmitted from the AP when an error is detected among the frames transmitted in step S701.
  • the error report may include information for reporting an error and requesting retransmission.
  • the error report may be included in a feedback frame (e.g., the feedback frame (350) of FIG. 3).
  • the error report may include information about the error.
  • the information about the error may be information directly indicating a frame in which an error is detected.
  • the information about the error may be information indirectly indicating a frame in which an error is detected.
  • the indirectly indicating information may include time information.
  • the time information includes at least one of TSF (time synchronization function) information, TSF information and an offset, a time interval using a plurality of pieces of TSF information, or a duration of a frame.
  • TSF time synchronization function
  • the first STA may recognize that an error has occurred in frame transmission based on the information about the error. For example, the first STA can recognize a frame in which an error is detected by recognizing the transmission time, transmission time interval, or transmission time length of the frame in which an error is detected based on time information.
  • the first STA transmits a retransmission frame (e.g., MPDU #2 (330) of FIG. 3) on the first link.
  • the retransmission frame may include a frame in which an error is detected.
  • the retransmission frame may include at least one of a frame in which an error is detected or a frame transmitted after the frame in which an error is detected (e.g., MPDU #3 (340) of FIG. 3).
  • the retransmission frame may be retransmitted after transmission of a frame being transmitted on the first link is completed.
  • the retransmission frame may be retransmitted after transmission of a frame being transmitted on the first link is stopped.
  • FIG. 8 is a flowchart illustrating an error reporting procedure according to an embodiment of the present disclosure.
  • FIG. 8 illustrates a procedure performed by an AP.
  • An AP e.g., AP MLD 1 of FIG. 3
  • An AP is connected to at least one of a first STA (e.g., STA MLD 1 of FIG. 3 ) or a second STA (e.g., STA MLD X of FIG. 3 ) using a first link and a second link.
  • the AP receives a plurality of frames (e.g., MPDU #2 (330) and MPDU #3 (340) of FIG. 3) from the first link.
  • the plurality of frames may be frames for transmitting data.
  • the plurality of frames may include an MPDU.
  • the plurality of frames may be frames having the same TID.
  • the plurality of frames may be frames having different TIDs.
  • Each frame may include a delimiter.
  • the delimiter may include at least one of an MPDU length indicator, a CRC, or a delimiter signature.
  • the delimiter may have a size of 32 bits.
  • the delimiter includes at least one of an MPDU including the delimiter or an SN (sequence number) of an MPDU to be transmitted next, TID information, or whether rapid recovery is required, for the receiver to detect an error.
  • the AP detects an error among the plurality of frames. At least one of the frames may not be decodable, or at least one frame may have an FCS error, etc. If the TIDs of the frames are the same, the AP can detect an error in one of the frames based on the SN. If the TIDs of the frames are not the same, or the TIDs are the same but the frames are not transmitted in the SN order, the AP can determine the point in time of error occurrence based on the delimiter. For example, if the AP receives a frame including a delimiter and energy is detected but cannot be decoded, the AP can detect an error in frame transmission.
  • the AP transmits an error report on the second link.
  • the error report is transmitted to the first STA.
  • the error report may be included in a feedback frame (e.g., the feedback frame (350) of FIG. 3).
  • the AP may stop transmitting a frame being transmitted to the second STA on the second link.
  • the AP may transmit the error report after transmission of the frame being transmitted is completed.
  • the error report may include information about the error.
  • the information about the error may be information directly indicating a frame in which an error is detected.
  • the information about the error may be information indirectly indicating a frame in which an error is detected.
  • the indirectly indicating information may include time information.
  • the time information includes at least one of TSF (time synchronization function) information, TSF information and an offset, a time interval using a plurality of pieces of TSF information, or a duration of a frame.
  • the AP receives a retransmission frame (e.g., MPDU #2 (330) of FIG. 3) from the first link.
  • the retransmission frame may include a frame in which an error is detected.
  • the retransmission frame may include at least one of a frame in which an error is detected or a frame transmitted after the frame in which an error is detected (e.g., MPDU #3 (340) of FIG. 3).
  • the retransmission frame may be retransmitted after transmission of a frame being transmitted on the first link is completed.
  • the retransmission frame may be retransmitted after transmission of a frame being transmitted on the first link is stopped.
  • the first STA or AP acquires a TXOP to transmit a frame.
  • the first STA or AP performs a channel access procedure.
  • the channel access procedure may be performed for each AC.
  • the frames transmitted by the first STA and the error report transmitted by the AP may be transmitted based on the same AC. Alternatively, the frames transmitted by the first STA and the error report transmitted by the AP may be transmitted based on different ACs.
  • the AP may stop transmitting a frame to the second STA based on the AC of the frame in which an error is detected, or transmit an error report after the transmission of the frame in which an error is detected is completed. Alternatively, the frame in which an error is detected or the error report may be transmitted with a separate high priority from the AC.
  • the methods according to the present invention may be implemented in the form of program commands that can be executed through various computer means and recorded on a computer-readable medium.
  • the computer-readable medium may include program commands, data files, data structures, etc., alone or in combination.
  • the program commands recorded on the computer-readable medium may be those specially designed and configured for the present invention or may be known and available to those skilled in the art of computer software.
  • Examples of computer-readable media include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory.
  • Examples of program instructions include not only machine language codes generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.
  • the above-described hardware devices can be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.
  • the present disclosure can be used in devices and recording media in a wireless LAN system.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Computer Security & Cryptography (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Pour un rapport d'erreur rapide dans un système LAN sans fil, ce procédé mis en œuvre dans une opération d'une station (STA) dans un système LAN sans fil comprend les étapes dans lesquelles : une pluralité de trames est transmise sur une première liaison ; un rapport d'erreur d'une trame dans laquelle une erreur est détectée parmi la pluralité de trames est reçu sur une seconde liaison ; et une trame de retransmission comprenant la trame dans laquelle l'erreur est détectée est transmise sur la base du rapport d'erreur, chacune de la pluralité de trames comprenant un délimiteur, et le délimiteur comprenant des informations pour distinguer chaque trame de la pluralité de trames.
PCT/KR2024/013811 2023-09-11 2024-09-11 Appareil et procédé de rapport d'erreur rapide dans un système lan sans fil Pending WO2025058403A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR20230120712 2023-09-11
KR10-2023-0120712 2023-09-11
KR1020240124060A KR20250038187A (ko) 2023-09-11 2024-09-11 무선랜 시스템에서 빠른 오류 보고를 위한 장치 및 방법
KR10-2024-0124060 2024-09-11

Publications (1)

Publication Number Publication Date
WO2025058403A1 true WO2025058403A1 (fr) 2025-03-20

Family

ID=95022370

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2024/013811 Pending WO2025058403A1 (fr) 2023-09-11 2024-09-11 Appareil et procédé de rapport d'erreur rapide dans un système lan sans fil

Country Status (1)

Country Link
WO (1) WO2025058403A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20160125992A (ko) * 2014-03-10 2016-11-01 엘지전자 주식회사 무선랜에서 재전송 방법 및 장치
KR20220165729A (ko) * 2020-04-08 2022-12-15 퀄컴 인코포레이티드 다중-링크 디바이스들에 대한 조기 중요 업데이트 표시들
WO2023055029A1 (fr) * 2021-09-30 2023-04-06 주식회사 윌러스표준기술연구소 Procédé de communication sans fil utilisant de multiples liaisons et terminal de communication sans fil utilisant le procédé
US20230231656A1 (en) * 2022-01-19 2023-07-20 Samsung Electronics Co., Ltd. Quick recovery indication and retransmission request

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20160125992A (ko) * 2014-03-10 2016-11-01 엘지전자 주식회사 무선랜에서 재전송 방법 및 장치
KR20220165729A (ko) * 2020-04-08 2022-12-15 퀄컴 인코포레이티드 다중-링크 디바이스들에 대한 조기 중요 업데이트 표시들
WO2023055029A1 (fr) * 2021-09-30 2023-04-06 주식회사 윌러스표준기술연구소 Procédé de communication sans fil utilisant de multiples liaisons et terminal de communication sans fil utilisant le procédé
US20230231656A1 (en) * 2022-01-19 2023-07-20 Samsung Electronics Co., Ltd. Quick recovery indication and retransmission request

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
AHMED IBRAHIM (SAMSUNG RESEARCH AMERICA): "Quick Recovery Mode for MLO", IEEE DRAFT; 11-22-0371-00-00BE-QUICK-RECOVERY-MODE-FOR-MLO, vol. 802.11 EHT; 802.11be, no. 0, 23 February 2022 (2022-02-23), US, pages 1 - 9, XP068189104 *

Similar Documents

Publication Publication Date Title
US11792829B2 (en) Method and apparatus for multi-link operations
US10880874B2 (en) Method for transmitting a response request frame and a response frame in a multi-user based wireless communication system
WO2011065746A2 (fr) Procédé de récupération d'une trame dont la transmission a échoué dans un système de communication sans fil sur une base mu-mimo
WO2011065743A2 (fr) Procédés de transmission d'une trame dans un système de communication sans fil sur une base multi-utilisateurs
WO2021201504A1 (fr) Procédé et dispositif de mise à jour de paramètres dans un système de communication prenant en charge une liaison multiple
WO2021235743A1 (fr) Procédé et dispositif de communication basée sur un fonctionnement à faible énergie dans un système de communication prenant en charge une liaison multiple
WO2021206378A1 (fr) Procédé et appareil de transmission et de réception de données dans un système de communication prenant en charge de multiples liaisons
WO2022039482A1 (fr) Procédé et dispositif d'économie d'énergie dans un système de communication prenant en charge des liaisons multiples
WO2021225328A1 (fr) Procédé et dispositif d'indication de transmission de données dans un système de communication prenant en charge de multiples liaisons
WO2022216086A1 (fr) Procédé et dispositif de fonctionnement de mlsr dans un lan sans fil
WO2021210896A1 (fr) Procédé et dispositif pour une communication directe dans un système de réseau local sans fil
WO2022075703A1 (fr) Procédé et dispositif de fonctionnement non-str dans un système de communication prenant en charge des liaisons multiples
WO2022007728A9 (fr) Procédé et appareil de reprise sur erreur de liaison
WO2024025357A1 (fr) Procédé et appareil de rétablissement dynamique de liaisons multiples
WO2022250414A1 (fr) Procédé et dispositif pour une communication directe dans un réseau local sans fil
WO2023277492A1 (fr) Procédé et dispositif de fonctionnement d'une emlsr dans un lan sans fil
US11329698B2 (en) Electronic apparatus
WO2025058403A1 (fr) Appareil et procédé de rapport d'erreur rapide dans un système lan sans fil
WO2025147182A1 (fr) Procédé et appareil de synchronisation de communication par répartition dans le temps à liaisons multiples dans un lan sans fil
WO2023101469A1 (fr) Procédé et appareil de récupération à partir d'une erreur de transmission dans un système de communication
JPH10173668A (ja) Ｌａｎシステム
WO2023059030A1 (fr) Procédé et dispositif de transmission inverse de données rapides dans un système de communication
WO2022245075A1 (fr) Procédé et dispositif d'émission et de réception de trame de réponse dans un système de communication prenant en charge de multiples liaisons
WO2022231217A1 (fr) Procédé et dispositif de transmission et de réception de données dans un système de communication prenant en charge de multiples liaisons
WO2025058468A1 (fr) Appareil et procédé de récupération rapide d'erreurs dans système lan sans fil

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24865842

Country of ref document: EP

Kind code of ref document: A1