WO2017209501A1 - Procédé de transmission d'une trame de liaison montante dans un système lan sans fil, et terminal sans fil utilisant ledit procédé - Google Patents

Procédé de transmission d'une trame de liaison montante dans un système lan sans fil, et terminal sans fil utilisant ledit procédé Download PDF

Info

Publication number
WO2017209501A1
WO2017209501A1 PCT/KR2017/005664 KR2017005664W WO2017209501A1 WO 2017209501 A1 WO2017209501 A1 WO 2017209501A1 KR 2017005664 W KR2017005664 W KR 2017005664W WO 2017209501 A1 WO2017209501 A1 WO 2017209501A1
Authority
WO
WIPO (PCT)
Prior art keywords
resource unit
frame
trigger
random
sta
Prior art date
Application number
PCT/KR2017/005664
Other languages
English (en)
Korean (ko)
Inventor
박현희
류기선
김서욱
김정기
조한규
Original Assignee
엘지전자 주식회사
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 엘지전자 주식회사 filed Critical 엘지전자 주식회사
Publication of WO2017209501A1 publication Critical patent/WO2017209501A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access, e.g. scheduled or random access
    • H04W74/08—Non-scheduled or contention based access, e.g. random access, ALOHA, CSMA [Carrier Sense Multiple Access]
    • 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 disclosure relates to wireless communication, and more particularly, to a method for transmitting an uplink frame in a wireless LAN system and a wireless terminal using the same.
  • next-generation WLANs 1) enhancements to the Institute of Electronics and Electronics Engineers (IEEE) 802.11 physical physical access (PHY) and medium access control (MAC) layers in the 2.4 GHz and 5 GHz bands, and 2) spectral efficiency and area throughput. aims to improve performance in real indoor and outdoor environments, such as in environments where interference sources exist, dense heterogeneous network environments, and high user loads.
  • IEEE Institute of Electronics and Electronics Engineers
  • PHY physical physical access
  • MAC medium access control
  • next-generation WLAN The environment mainly considered in the next-generation WLAN is a dense environment having many access points (APs) and a station (STA), and improvements in spectral efficiency and area throughput are discussed in such a dense environment.
  • next generation WLAN there is an interest in improving practical performance not only in an indoor environment but also in an outdoor environment, which is not much considered in a conventional WLAN.
  • scenarios such as a wireless office, a smarthome, a stadium, and a hotspot are of interest in the next generation WLAN.
  • a discussion of performance improvement of a WLAN system in an environment in which APs and STAs are concentrated is in progress.
  • An object of the present specification is to provide a method for transmitting an uplink frame and a wireless terminal using the same in a WLAN system having improved performance.
  • a method for transmitting an uplink frame includes a first allocation information indicating a plurality of resource units for OFDMA-based random access;
  • the first random resource unit indicates a plurality of resource units for OFDMA-based random access without transmission of the trigger-based uplink frame.
  • a method for transmitting an uplink frame in a WLAN system having improved performance and a wireless terminal using the same are provided.
  • FIG. 1 is a conceptual diagram illustrating a structure of a WLAN system.
  • FIG. 2 is a diagram illustrating an example of a PPDU used in the IEEE standard.
  • FIG. 3 is a diagram illustrating an example of a HE PPDU.
  • 4 is a diagram illustrating an arrangement of resource units used on a 20 MHz band.
  • 5 is a diagram illustrating an arrangement of resource units used on a 40 MHz band.
  • 6 is a diagram illustrating an arrangement of resource units used on an 80 MHz band.
  • FIG. 7 is a diagram illustrating another example of the HE-PPDU.
  • FIG. 8 is a block diagram illustrating an example of HE-SIG-B according to the present embodiment.
  • FIG 9 shows an example of a trigger frame in this embodiment.
  • FIG 11 shows an example of a subfield included in an individual user information field in this embodiment.
  • FIG. 12 is a conceptual diagram illustrating a scanning method in a WLAN.
  • FIG. 13 is a conceptual diagram illustrating an authentication and combining procedure after scanning of an AP and an STA.
  • FIG. 14 is a diagram illustrating an OFDMA based random access procedure by way of example.
  • 15 is a diagram illustrating an OFDMA based random access procedure according to the present embodiment.
  • 16 is a flowchart illustrating an OFDMA based random access procedure according to the present embodiment.
  • 17 and 18 illustrate conceptual diagrams of a trigger frame for an OFDMA-based random access procedure according to another embodiment.
  • 19 is a block diagram illustrating a wireless terminal to which an embodiment can be applied.
  • FIG. 1 is a conceptual diagram illustrating a structure of a WLAN system.
  • FIG. 1A shows the structure of an infrastructure network of the Institute of Electrical and Electronic Engineers (IEEE) 802.11.
  • IEEE Institute of Electrical and Electronic Engineers
  • the WLAN system 10 of FIG. 1A may include at least one basic service set (hereinafter, referred to as 'BSS', 100, 105).
  • the BSS is a set of access points (APs) and stations (STAs) that can successfully synchronize and communicate with each other, and is not a concept indicating a specific area.
  • APs access points
  • STAs stations
  • the first BSS 100 may include a first AP 110 and one first STA 100-1 coupled with the first AP 110.
  • the second BSS 105 may include a second AP 130 and one or more STAs 105-1 and 105-2 coupled with the second AP 130.
  • the infrastructure BSS may include at least one STA, AP (110, 130) providing a distribution service (Distribution Service) and a distribution system (DS, 120) connecting a plurality of APs. have.
  • the distributed system 120 may connect the plurality of BSSs 100 and 105 to implement an extended service set 140 which is an extended service set.
  • the ESS 140 may be used as a term indicating one network to which at least one AP 110 or 130 is connected through the distributed system 120.
  • At least one AP included in one ESS 140 may have the same service set identification (hereinafter, referred to as SSID).
  • the portal 150 may serve as a bridge for connecting the WLAN network (IEEE 802.11) with another network (for example, 802.X).
  • a network between APs 110 and 130 and a network between APs 110 and 130 and STAs 100-1, 105-1, and 105-2 may be implemented. Can be.
  • FIG. 1B is a conceptual diagram illustrating an independent BSS.
  • the WLAN system 15 of FIG. 1B performs communication by setting a network between STAs without the APs 110 and 130, unlike FIG. 1A. It may be possible to.
  • a network that performs communication by establishing a network even between STAs without the APs 110 and 130 is defined as an ad-hoc network or an independent basic service set (BSS).
  • BSS basic service set
  • the IBSS 15 is a BSS operating in an ad-hoc mode. Since IBSS does not contain an AP, there is no centralized management entity. Thus, in the IBSS 15, the STAs 150-1, 150-2, 150-3, 155-4, and 155-5 are managed in a distributed manner.
  • All STAs 150-1, 150-2, 150-3, 155-4, and 155-5 of the IBSS may be mobile STAs, and access to a distributed system is not allowed. All STAs of the IBSS form a self-contained network.
  • the STA referred to herein includes a medium access control (MAC) conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard and a physical layer interface to a wireless medium.
  • MAC medium access control
  • IEEE Institute of Electrical and Electronics Engineers 802.11
  • any functional medium it can broadly be used to mean both an AP and a non-AP Non-AP Station (STA).
  • the STA referred to herein includes a mobile terminal, a wireless device, a wireless transmit / receive unit (WTRU), a user equipment (UE), and a mobile station (MS). It may also be called various names such as a mobile subscriber unit or simply a user.
  • WTRU wireless transmit / receive unit
  • UE user equipment
  • MS mobile station
  • FIG. 2 is a diagram illustrating an example of a PPDU used in the IEEE standard.
  • PPDUs PHY protocol data units
  • LTF and STF fields included training signals
  • SIG-A and SIG-B included control information for the receiving station
  • data fields included user data corresponding to the PSDU.
  • This embodiment proposes an improved technique for the signal (or control information field) used for the data field of the PPDU.
  • the signal proposed in this embodiment may be applied on a high efficiency PPDU (HE PPDU) according to the IEEE 802.11ax standard. That is, the signals to be improved in the present embodiment may be HE-SIG-A and / or HE-SIG-B included in the HE PPDU. Each of HE-SIG-A and HE-SIG-B may also be represented as SIG-A or SIG-B.
  • the improved signal proposed by this embodiment is not necessarily limited to the HE-SIG-A and / or HE-SIG-B standard, and controls / control of various names including control information in a wireless communication system for transmitting user data. Applicable to data fields.
  • FIG. 3 is a diagram illustrating an example of a HE PPDU.
  • the control information field proposed in this embodiment may be HE-SIG-B included in the HE PPDU as shown in FIG. 3.
  • the HE PPDU according to FIG. 3 is an example of a PPDU for multiple users.
  • the HE-SIG-B may be included only for the multi-user, and the HE-SIG-B may be omitted in the PPDU for the single user.
  • a HE-PPDU for a multiple user includes a legacy-short training field (L-STF), a legacy-long training field (L-LTF), a legacy-signal (L-SIG), High efficiency-signal A (HE-SIG-A), high efficiency-signal-B (HE-SIG-B), high efficiency-short training field (HE-STF), high efficiency-long training field (HE-LTF)
  • L-STF legacy-short training field
  • L-SIG-A High efficiency-signal A
  • HE-SIG-B high efficiency-signal-B
  • HE-STF high efficiency-long training field
  • HE-LTF High efficiency-long training field
  • It may include a data field (or MAC payload) and a PE (Packet Extension) field.
  • Each field may be transmitted during the time period shown (ie, 4 or 8 ms, etc.). Detailed description of each field of FIG. 3 will be described later.
  • resource units (RUs) used on a 20 MHz band.
  • resource units (RUs) corresponding to different numbers of tones may be used to configure some fields of the HE-PPDU.
  • resources may be allocated in units of RUs shown for HE-STF, HE-LTF, and data fields.
  • 26-units ie, units corresponding to 26 tones
  • Six tones may be used as the guard band in the leftmost band of the 20 MHz band, and five tones may be used as the guard band in the rightmost band of the 20 MHz band.
  • seven DC tones are inserted into the center band, that is, the DC band, and 26-units corresponding to each of the 13 tones may exist to the left and right of the DC band.
  • other bands may be allocated 26-unit, 52-unit, 106-unit. Each unit can be assigned for a receiving station, i. E. A user.
  • the RU arrangement of FIG. 4 is utilized not only for the situation for a plurality of users (MU), but also for the situation for a single user (SU), in which case one 242-unit is shown as shown at the bottom of FIG. It is possible to use and in this case three DC tones can be inserted.
  • FIG. 5 is a diagram illustrating an arrangement of resource units (RUs) used on a 40 MHz band.
  • the example of FIG. 5 may also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, and the like.
  • five DC tones can be inserted at the center frequency, 12 tones are used as the guard band in the leftmost band of the 40 MHz band, and 11 tones are in the rightmost band of the 40 MHz band. This guard band can be used.
  • the 484-RU may be used when used for a single user. Meanwhile, the specific number of RUs may be changed as in the example of FIG. 4.
  • FIG. 6 is a diagram illustrating an arrangement of resource units (RUs) used on an 80 MHz band.
  • the example of FIG. 6 may also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, and the like. have.
  • seven or five DC tones can be inserted at the center frequency, and 12 tones are used as the guard band in the leftmost band of the 80 MHz band, and in the rightmost band of the 80 MHz band. Eleven tones can be used as guard bands.
  • 996-RU may be used when used for a single user. Meanwhile, the specific number of RUs may be changed as in the example of FIGS. 4 and 5.
  • FIG. 7 is a diagram illustrating another example of the HE-PPDU.
  • FIG. 7 is another example illustrating the HE-PPDU block of FIG. 3 in terms of frequency.
  • the illustrated L-STF 700 may include a short training orthogonal frequency division multiplexing symbol.
  • the L-STF 700 includes frame detection, automatic gain control (AGC), diversity detection, and coarse frequency / time synchronization.
  • AGC automatic gain control
  • the L-LTF 710 may include a long training orthogonal frequency division multiplexing symbol.
  • the L-LTF 710 may be used for fine frequency / time synchronization and channel prediction.
  • L-SIG 720 may be used to transmit control information.
  • the L-SIG 720 may include information about a data rate and a data length.
  • the L-SIG 720 may be repeatedly transmitted. That is, the L-SIG 720 may be configured in a repeating format (for example, may be referred to as an R-LSIG).
  • the HE-SIG-A 730 may include control information common to the receiving station.
  • the HE-SIG-A 730 may include 1) a DL / UL indicator, 2) a BSS color field which is an identifier of a BSS, 3) a field indicating a remaining time of a current TXOP interval, 3) 20, Bandwidth field indicating 40, 80, 160, 80 + 80 Mhz, 4) Field indicating MCS scheme applied to HE-SIG-B, 5) HE-SIB-B is dual subcarrier modulation for MCS ( field indicating whether the modulation is performed using a dual subcarrier modulation), 6) a field indicating the number of symbols used for the HE-SIG-B, and 7) a field indicating whether the HE-SIG-B is generated over the entire band.
  • Field, 8) field indicating the number of symbols in the HE-LTF, 8) field indicating the length and CP length of the HE-LTF, 9) field indicating whether additional OFDM symbols exist for LDPC coding, 10) 11) field indicating the control information on the PE (packet extension), 11) field indicating the information on the CRC field of the HE-SIG-A, etc. may be included. All. Specific fields of the HE-SIG-A may be added or omitted. In addition, some fields may be added or omitted in other environments where the HE-SIG-A is not a multi-user (MU) environment.
  • MU multi-user
  • the HE-SIG-B 740 may be included only when it is a PPDU for a multi-user (MU) as described above. Basically, the HE-SIG-A 730 or the HE-SIG-B 740 may include resource allocation information (or virtual resource allocation information) for at least one receiving STA.
  • the HE-SIG-B 740 is described in more detail with reference to FIG. 8 described below.
  • the previous field of the HE-SIG-B 740 on the MU PPDU may be transmitted in duplicated form.
  • the HE-SIG-B 740 transmitted in a part of the frequency band (for example, the fourth frequency band) is the frequency band (that is, the fourth frequency band) of the Control information for a data field and a data field of another frequency band (eg, the second frequency band) except for the corresponding frequency band may be included.
  • the HE-SIG-B 740 of a specific frequency band (eg, the second frequency band) duplicates the HE-SIG-B 740 of another frequency band (eg, the fourth frequency band). It can be one format.
  • the HE-SIG-B 740 may be transmitted in an encoded form on all transmission resources.
  • the field after the HE-SIG-B 740 may include individual information for each receiving STA that receives the PPDU.
  • the HE-STF 750 may be used to improve automatic gain control estimation in a multiple input multiple output (MIMO) environment or an orthogonal frequency-division multiple access (OFDMA) environment.
  • MIMO multiple input multiple output
  • OFDMA orthogonal frequency-division multiple access
  • the HE-LTF 760 may be used to estimate a channel in a MIMO environment or an OFDMA environment.
  • the size of the FFT / IFFT applied to the field after the HE-STF 750 and the HE-STF 750 may be different from the size of the FFT / IFFT applied to the field before the HE-STF 750.
  • the size of the FFT / IFFT applied to the fields after the HE-STF 750 and the HE-STF 750 may be four times larger than the size of the IFFT applied to the field before the HE-STF 750.
  • a field of s is called a first field
  • at least one of the data field 770, the HE-STF 750, and the HE-LTF 760 may be referred to as a second field.
  • the first field may include a field related to a legacy system
  • the second field may include a field related to a HE system.
  • 256 FFT / IFFT is applied for a bandwidth of 20 MHz
  • 512 FFT / IFFT is applied for a bandwidth of 40 MHz
  • 1024 FFT / IFFT is applied for a bandwidth of 80 MHz
  • 2048 FFT for a bandwidth of 160 MHz continuous or discontinuous 160 MHz.
  • / IFFT can be applied.
  • spacing may be applied to a subcarrier having a size of 312.5 kHz, which is a conventional subcarrier spacing, and space may be applied to a subcarrier having a size of 78.125 kHz, as a second field of the HE PPDU.
  • the length of an OFDM symbol may be a value obtained by adding a length of a guard interval (GI) to an IDFT / DFT length.
  • the length of the GI can be various values such as 0.4 ⁇ s, 0.8 ⁇ s, 1.6 ⁇ s, 2.4 ⁇ s, 3.2 ⁇ s.
  • the frequency band used by the first field and the frequency band used by the second field are represented in FIG. 7, they may not exactly coincide with each other.
  • the main band of the first field L-STF, L-LTF, L-SIG, HE-SIG-A, HE-SIG-B
  • HE-STF the main band of the first field
  • HE-LTF, Data the second field
  • the interface may be inconsistent. 4 to 6, since a plurality of null subcarriers, DC tones, guard tones, etc. are inserted in the process of arranging the RU, it may be difficult to accurately match the interface.
  • the user may receive the HE-SIG-A 730 and may be instructed to receive the downlink PPDU based on the HE-SIG-A 730.
  • the STA may perform decoding based on the changed FFT size from the field after the HE-STF 750 and the HE-STF 750.
  • the STA may stop decoding and configure a network allocation vector (NAV).
  • NAV network allocation vector
  • the cyclic prefix (CP) of the HE-STF 750 may have a larger size than the CP of another field, and during this CP period, the STA may perform decoding on the downlink PPDU by changing the FFT size.
  • data (or frame) transmitted from the AP to the STA is called downlink data (or downlink frame), and data (or frame) transmitted from the STA to the AP is called uplink data (or uplink frame).
  • downlink data or downlink frame
  • uplink data or uplink frame
  • the transmission from the AP to the STA may be expressed in terms of downlink transmission
  • the transmission from the STA to the AP may be expressed in terms of uplink transmission.
  • each of the PHY protocol data units (PPDUs), frames, and data transmitted through downlink transmission may be expressed in terms of a downlink PPDU, a downlink frame, and downlink data.
  • the PPDU may be a data unit including a PPDU header and a physical layer service data unit (PSDU) (or MAC protocol data unit (MPDU)).
  • PSDU physical layer service data unit
  • MPDU MAC protocol data unit
  • the PPDU header may include a PHY header and a PHY preamble
  • the PSDU (or MPDU) may be a data unit including a frame (or an information unit of a MAC layer) or indicating a frame.
  • the PHY header may be referred to as a physical layer convergence protocol (PLCP) header in another term
  • the PHY preamble may be expressed as a PLCP preamble in another term.
  • each of the PPDUs, frames, and data transmitted through uplink transmission may be represented by the term uplink PPDU, uplink frame, and uplink data.
  • the entire bandwidth may be used for downlink transmission to one STA and uplink transmission to one STA based on single (or single) -orthogonal frequency division multiplexing (SUDM) transmission.
  • the AP may perform downlink (DL) multi-user (MU) transmission based on MU MIMO (multiple input multiple output), and such transmission is DL MU MIMO transmission. It can be expressed as.
  • an orthogonal frequency division multiple access (OFDMA) based transmission method is supported for uplink transmission and downlink transmission. That is, uplink / downlink communication may be performed by allocating data units (eg, RUs) corresponding to different frequency resources to the user.
  • the AP performs OFDMA.
  • DL MU transmission may be performed based on the above, and such transmission may be expressed in terms of DL MU OFDMA transmission.
  • the AP may transmit downlink data (or downlink frame, downlink PPDU) to each of the plurality of STAs through the plurality of frequency resources on the overlapped time resources.
  • the plurality of frequency resources may be a plurality of subbands (or subchannels) or a plurality of resource units (RUs).
  • DL MU OFDMA transmission can be used with DL MU MIMO transmission. For example, DL MU MIMO transmission based on a plurality of space-time streams (or spatial streams) is performed on a specific subband (or subchannel) allocated for DL MU OFDMA transmission. Can be.
  • UL MU transmission uplink multi-user transmission
  • UL MU transmission may be supported by a plurality of STAs to transmit data to the AP on the same time resource.
  • Uplink transmission on the overlapped time resource by each of the plurality of STAs may be performed in the frequency domain or the spatial domain.
  • different frequency resources may be allocated as uplink transmission resources for each of the plurality of STAs based on OFDMA.
  • the different frequency resources may be different subbands (or subchannels) or different resource units (RUs).
  • Each of the plurality of STAs may transmit uplink data to the AP through different allocated frequency resources.
  • the transmission method through these different frequency resources may be represented by the term UL MU OFDMA transmission method.
  • each of the plurality of STAs When uplink transmission by each of the plurality of STAs is performed in the spatial domain, different space-time streams (or spatial streams) are allocated to each of the plurality of STAs, and each of the plurality of STAs transmits uplink data through different space-time streams. Can transmit to the AP.
  • the transmission method through these different spatial streams may be represented by the term UL MU MIMO transmission method.
  • the UL MU OFDMA transmission and the UL MU MIMO transmission may be performed together.
  • UL MU MIMO transmission based on a plurality of space-time streams (or spatial streams) may be performed on a specific subband (or subchannel) allocated for UL MU OFDMA transmission.
  • a multi-channel allocation method was used to allocate a wider bandwidth (for example, a bandwidth exceeding 20 MHz) to one UE.
  • the multi-channel may include a plurality of 20 MHz channels when one channel unit is 20 MHz.
  • a primary channel rule is used to allocate a wide bandwidth to the terminal. If the primary channel rule is used, there is a constraint for allocating a wide bandwidth to the terminal. Specifically, according to the primary channel rule, when a secondary channel adjacent to the primary channel is used in an overlapped BSS (OBSS) and 'busy', the STA may use the remaining channels except the primary channel. Can not.
  • OBSS overlapped BSS
  • the STA can transmit the frame only through the primary channel, thereby being limited to the transmission of the frame through the multi-channel. That is, the primary channel rule used for multi-channel allocation in the existing WLAN system may be a big limitation in obtaining high throughput by operating a wide bandwidth in the current WLAN environment where there are not many OBSS.
  • a WLAN system supporting the OFDMA technology supporting the OFDMA technology. That is, the above-described OFDMA technique is applicable to at least one of downlink and uplink.
  • the above-described MU-MIMO technique may be additionally applied to at least one of downlink and uplink.
  • OFDMA technology is used, a plurality of terminals may be used simultaneously instead of one terminal without using a primary channel rule. Therefore, wide bandwidth operation is possible, and the efficiency of the operation of radio resources can be improved.
  • the AP when uplink transmission by each of a plurality of STAs (eg, non-AP STAs) is performed in the frequency domain, the AP has different frequency resources for each of the plurality of STAs based on OFDMA. It may be allocated as a link transmission resource. In addition, as described above, different frequency resources may be different subbands (or subchannels) or different resource units (RUs).
  • OFDMA orthogonal frequency division multiple access
  • Different frequency resources for each of the plurality of STAs may be indicated through a trigger frame.
  • FIG. 8 is a block diagram showing an example of the HE-SIG-B according to the present embodiment.
  • the HE-SIG-B field includes a common field at the beginning, and the common field can be encoded separately from the following field. That is, as shown in FIG. 8, the HE-SIG-B field may include a common field including common control information and a user-specific field including user-specific control information.
  • the common field may include a corresponding CRC field and may be coded into one BCC block. Subsequent user-specific fields may be coded into one BCC block, including a "user-specific field" for two users (2 users), a CRC field corresponding thereto, and the like, as shown.
  • the trigger frame of FIG. 9 allocates resources for uplink multiple-user transmission and can be transmitted from the AP.
  • the trigger frame may consist of a MAC frame and may be included in a PPDU. For example, it may be transmitted through the PPDU shown in FIG. 3, through the legacy PPDU shown in FIG. 2, or through a PPDU specifically designed for the trigger frame. If transmitted through the PPDU of FIG. 3, the trigger frame may be included in the illustrated data field.
  • Each field shown in FIG. 9 may be partially omitted, and another field may be added. In addition, the length of each field may be varied as shown.
  • the frame control field 910 of FIG. 9 includes information about the version of the MAC protocol and other additional control information, and the duration field 920 includes time information for setting the NAV described below.
  • Information about an identifier (eg, AID) of the terminal may be included.
  • the RA field 930 includes address information of the receiving STA of the corresponding trigger frame and may be omitted as necessary.
  • the TA field 940 includes address information of an STA (for example, an AP) that transmits a corresponding trigger frame, and the common information field 950 is common to be applied to a receiving STA that receives the corresponding trigger frame. Contains control information
  • per user information fields 960 # 1 to 960 # N corresponding to the number of receiving STAs receiving the trigger frame of FIG. 9.
  • the individual user information field may be referred to as a "RU assignment field.”
  • the trigger frame of FIG. 9 may include a padding field 970 and a frame check sequence field 980.
  • Each of the per user information fields 960 # 1 to 960 # N shown in FIG. 9 preferably includes a plurality of subfields.
  • FIG. 10 shows an example of a common information field in this embodiment. Some of the subfields of FIG. 10 may be omitted, and other subfields may be added. In addition, the length of each illustrated subfield may be modified.
  • the illustrated length field 1010 has the same value as the length field of the L-SIG field of the uplink PPDU transmitted corresponding to the trigger frame, and the length field of the L-SIG field of the uplink PPDU indicates the length of the uplink PPDU.
  • the length field 1010 of the trigger frame may be used to indicate the length of the corresponding uplink PPDU.
  • the cascade indicator field 1020 indicates whether a cascade operation is performed.
  • the cascade operation means that downlink MU transmission and uplink MU transmission are performed together in the same TXOP. That is, after downlink MU transmission is performed, it means that uplink MU transmission is performed after a predetermined time (eg, SIFS).
  • a predetermined time eg, SIFS.
  • only one transmitting device (eg, AP) for downlink communication may exist, and a plurality of transmitting devices (eg, non-AP) for uplink communication may exist.
  • the CS request field 1030 indicates whether the state of the radio medium, the NAV, or the like should be considered in a situation in which the receiving apparatus receiving the trigger frame transmits the corresponding uplink PPDU.
  • the HE-SIG-A information field 1040 may include information for controlling the content of the SIG-A field (ie, the HE-SIG-A field) of the uplink PPDU transmitted in response to the corresponding trigger frame.
  • the CP and LTF type field 1050 may include information about the length of the LTF and the CP length of the uplink PPDU transmitted in response to the corresponding trigger frame.
  • the trigger type field 1060 may indicate the purpose for which the corresponding trigger frame is used, for example, normal triggering, triggering for beamforming, a request for Block ACK / NACK, and the like.
  • FIG. 10 shows an example of a common information field in this embodiment. Some of the subfields of FIG. 10 may be omitted, and other subfields may be added. In addition, the length of each illustrated subfield may be modified.
  • the illustrated length field 1010 has the same value as the length field of the L-SIG field of the uplink PPDU transmitted corresponding to the trigger frame, and the length field of the L-SIG field of the uplink PPDU indicates the length of the uplink PPDU.
  • the length field 1010 of the trigger frame may be used to indicate the length of the corresponding uplink PPDU.
  • the cascade indicator field 1020 indicates whether a cascade operation is performed.
  • the cascade operation means that downlink MU transmission and uplink MU transmission are performed together in the same TXOP. That is, after downlink MU transmission is performed, it means that uplink MU transmission is performed after a predetermined time (eg, SIFS).
  • a predetermined time eg, SIFS.
  • only one transmitting device (eg, AP) for downlink communication may exist, and a plurality of transmitting devices (eg, non-AP) for uplink communication may exist.
  • the CS request field 1030 indicates whether the state of the radio medium, the NAV, or the like should be considered in a situation in which the receiving apparatus receiving the trigger frame transmits the corresponding uplink PPDU.
  • the HE-SIG-A information field 1040 may include information for controlling the content of the SIG-A field (ie, the HE-SIG-A field) of the uplink PPDU transmitted in response to the corresponding trigger frame.
  • the CP and LTF type field 1050 may include information about the length of the LTF and the CP length of the uplink PPDU transmitted in response to the corresponding trigger frame.
  • the trigger type field 1060 may indicate the purpose for which the corresponding trigger frame is used, for example, normal triggering, triggering for beamforming, a request for Block ACK / NACK, and the like.
  • FIG. 11 shows an example of subfields included in the per user information field in this embodiment. Some of the subfields of FIG. 11 may be omitted, and other subfields may be added. In addition, the length of each illustrated subfield may be modified.
  • the user identifier field 1110 of FIG. 11 indicates an identifier of an STA (ie, a receiving STA) corresponding to per user information.
  • An example of the identifier may be all or part of an AID. have.
  • the user identifier field of FIG. 11 may be referred to as an association identifier (hereinafter, referred to as 'AID') field.
  • the RU Allocation field 1120 may be included. That is, when the receiving STA identified by the user identifier field 1110 transmits an uplink PPDU in response to the trigger frame of FIG. 9, the corresponding uplink PPDU through the RU indicated by the RU Allocation field 1120. Send.
  • the RU indicated by the RU Allocation field 1120 preferably indicates the RUs shown in FIGS. 4, 5, and 6.
  • the subfield of FIG. 11 may include a coding type field 1130.
  • the coding type field 1130 may indicate a coding type of an uplink PPDU transmitted in response to the trigger frame of FIG. 9. For example, when BCC coding is applied to the uplink PPDU, the coding type field 1130 is set to '1', and when LDPC coding is applied, the coding type field 1130 is set to '0'. Can be.
  • the subfield of FIG. 11 may include an MCS field 1140.
  • the MCS field 1140 may indicate an MCS scheme applied to an uplink PPDU transmitted in response to the trigger frame of FIG. 9. For example, when BCC coding is applied to the uplink PPDU, the coding type field 1130 is set to '1', and when LDPC coding is applied, the coding type field 1130 is set to '0'. Can be.
  • FIG. 12 is a conceptual diagram illustrating a scanning method in a WLAN.
  • a scanning method may be classified into passive scanning 1200 and active scanning 1250.
  • the passive scanning 1200 may be performed based on a beacon frame 1230 that the AP 1210 periodically broadcasts.
  • the AP 1210 of the WLAN may broadcast the beacon frame 1230 to the non-AP STA 1240 every specific period (eg, 100 msec).
  • the beacon frame 1230 may include information about the current network.
  • the non-AP STA 1240 may periodically receive the beacon frame 1230.
  • the non-AP STA 1240 may perform scanning on the AP 1210 and the channel based on the network information included in the beacon frame 1230.
  • the passive scanning method 1200 is a technique in which the non-AP STA 1240 receives the beacon frame 1230 transmitted from the AP 1210 without first transmitting the frame.
  • passive scanning 1200 has the advantage that the overall overhead incurred by data transmission / reception in the network is small.
  • scanning can be performed manually in proportion to the period of the beacon frame 1230, there is a disadvantage in that the time required to perform scanning increases.
  • beacon frame A detailed description of the beacon frame is described in IEEE Draft P802.11-REVmb TM / D4.1, July 2015 'IEEE Standard for Information Technology Telecommunications and information exchange between systems-Local and metropolitan area networks-Specific requirements Part' 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications (hereafter IEEE 802.11) 'are described in 8.3.3.2 beacon frame.
  • IEEE 802.11 Wireless LAN Medium Access Control
  • PHY Physical Layer
  • the active scanning 1250 is a technique in which a non-AP STA 1290 transmits a probe request frame 1270 to the AP 1260 to proactively perform scanning.
  • the AP 1260 may receive the probe request frame 1270 from the non-AP STA 1290.
  • the AP 1260 may wait for a random time to prevent frame collision.
  • the AP 1260 may transmit a probe response frame 1280 including network information to the non-AP STA 1290 in response to the probe request frame 1270.
  • the non-AP STA 1290 may acquire network information based on the received probe response frame 380.
  • the probe request frame 1270 is disclosed in IEEE 802.11 8.3.3.9 and the probe response frame 1280 is disclosed in IEEE 802.11 8.3.3.10.
  • the AP and the STA may perform an authentication and association procedure.
  • FIG. 13 is a conceptual diagram illustrating an authentication and combining procedure after scanning of an AP and an STA.
  • a non-AP STA may perform an authentication and association procedure with one of a plurality of APs that have completed a scanning procedure through passive / active scanning.
  • authentication and association procedures may be performed through two-way handshaking.
  • FIG. 13A is a conceptual diagram illustrating an authentication and combining procedure after passive scanning
  • FIG. 13B is a conceptual diagram illustrating an authentication and combining procedure after active scanning.
  • the authentication and association procedure can be performed regardless of whether an active scanning method or passive scanning was used.
  • the APs 1300 and 1350 may include a non-AP STA 1305 and 1355, an authentication request frame 1310, an authentication response frame 1320, and an association request frame. 1330, an association and association procedure may be performed by exchanging an association response frame 1340.
  • the authentication procedure may be performed by transmitting the authentication request frame 1310 to the APs 1300 and 1350 in the non-AP STAs 1305 and 1355.
  • the APs 1300 and 1350 may transmit an authentication response frame 1320 to the non-AP STAs 1305 and 1355 in response to the authentication request frame 1310.
  • Authentication frame format is disclosed in IEEE 802.11 8.3.3.11.
  • the association procedure may be performed by transmitting the association request frame 1330 to the APs 1300 and 1305 in the non-AP STAs 1305 and 1355.
  • the APs 1300 and 1350 may transmit the association response frame 1340 to the non-AP STAs 1305 and 1355 in response to the association request frame 1330.
  • the association request frame 1330 may include information regarding the capability of the non-AP STAs 1305 and 1355.
  • the APs 1300 and 1350 determine whether support for the non-AP STAs 1305 and 1355 is possible based on the information on the performance of the non-AP STAs 1305 and 1355 included in the association request frame 1330. can do.
  • the AP 1300 or 1350 may include a non-binding in the association response frame 1340 by including whether the acceptance request frame 1340 is accepted and the reason thereof, and capability information supported by the AP 1300 and 1350. It may transmit to the AP STAs 1305 and 1355.
  • Association frame format is disclosed in IEEE 802.11 8.3.3.5/8.3.3.6.
  • a normal data transmission and reception procedure may be performed between the AP and the STA.
  • FIG. 14 is a diagram illustrating an OFDMA based random access procedure by way of example.
  • the horizontal axis of the AP 1400 may indicate a time t of the AP 1400.
  • the horizontal axis of the first STA 1410 represents the time t1 of the first STA 1410
  • the horizontal axis of the second STA 1420 represents the time t2 of the second STA 1420
  • the third STA The horizontal axis of 1430 may represent a time t3 of the third STA 1430.
  • contention window information (CW) information associated with a value set in an OFDMA backoff counter (hereinafter, referred to as an 'OBO counter') may be signaled to a plurality of STAs through a beacon frame (not shown). Can be.
  • CW contention window information
  • the trigger frame for the random access procedure mentioned may be referred to as a trigger frame for random access (TR).
  • the random trigger frame TR has the frame format of FIGS. 9 to 11 described above.
  • an OBO counter for each STA may be defined separately.
  • an OFDMA contention window ('OCW'), which is a range of an initial value that can be set in an OBO counter, may be defined based on contention window information.
  • the OFDMA contention window may be set based on contention window (CW) information included in a beacon frame (not shown) transmitted before the first random trigger frame 1401 by the AP 1400.
  • the contention window information included in the beacon frame (not shown) may include an OCWmin value for the OCW.
  • Each STA that performs an OFDMA-based random access procedure may individually set an initial OBO for an OBO counter to a randomly selected value in an interval of [0, OCWmin] based on the received contention window information. .
  • the first to third STAs 1410, 1420, and 1430 are assigned to a beacon frame (not shown).
  • the first to third initial values (OBO) for the first to third OBO counters corresponding to each STA may be individually set based on the included contention window information.
  • CW contention window
  • the first STA 1410 may set the integer value v1 arbitrarily selected in [0, CWmin] as the first initial value (OBO1) for the first OBO counter. For example, the first STA 1410 may set '3' selected in [0, 7] as a first initial value (OBO1) for the first OBO counter.
  • the second STA 1420 may set an integer value v2 arbitrarily selected in [0, CWmin] as a second initial value (OBO2) for the second OBO counter.
  • the second STA 1420 may set '1' selected in [0, 7] as a second initial value (OBO2) for the second OBO counter.
  • the third STA 1430 may set the integer value v3 arbitrarily selected in [0, CWmin] as a third initial value (OBO3) for the third OBO counter.
  • the third STA 1430 may set '4' selected in [0, 7] as the third initial value (OBO3) for the third OBO counter.
  • the AP 1400 may transmit a first random trigger frame 1401.
  • STAs that want to perform a random access procedure in the first cycles T1 to T7 are the first and second STAs 1410 and 1420.
  • the first random trigger frame 1401 may include first allocation information indicating a plurality of resource units (RUs) allocated by the AP 1400.
  • the first allocation information may indicate two resource units RU1 and RU2.
  • All of the first user identifier fields of the first user-specific field (eg, 960 # 1 of FIG. 9) of the first random trigger frame 1401 may be set to '0'.
  • the first RU allocation field of the first user-specific field may be set to indicate the first resource unit RU1.
  • All of the second user identifier fields of the second user-specific field (eg, 960 # 2 of FIG. 9) of the first random trigger frame 1401 may be set to '0'.
  • the second RU allocation field of the second user-specific field may be set to indicate the second resource unit RU2.
  • Each STA that receives the random trigger frame may determine the resource unit (RU) indicated in the RU allocation field corresponding to the user identifier field set to '0' as the resource unit (RU) used in the OFDMA-based random access procedure. .
  • the first STA 1410 may perform a first countdown operation.
  • the first STA 1410 may decrease the first initial value v1 set in the first OBO counter by the number '2' of the first and second resource units RU1 and RU2. Accordingly, the first count value v1 'updated to the first OBO count becomes' 1'.
  • the second STA 1420 may perform a second countdown operation.
  • the second STA 1420 may update the value v2 'of the second OBO counter to' 0 'by decreasing the second initial value v2 set in the second OBO counter. Accordingly, the second countdown operation may be completed.
  • the second STA 1420 may select one of the RU sets RU1 and RU2 allocated to the first random trigger frame 1401 as the random resource unit. For example, the second STA 1420 may select the second resource unit RU2 as a random resource unit for transmitting an uplink frame.
  • the second section T2-T3 may be a short inter-frame space (SIFS).
  • SIFS short inter-frame space
  • the second STA 1420 accesses the first trigger based frame (HE Trigger-based PPDU_1, 1402) corresponding to the first random trigger frame 1401 using the random resource unit. 1400).
  • the fourth section T4-T5 may be SIFS.
  • the second STA 1420 may receive the ACK frame 1403 in response to the first trigger based frame 1402. have.
  • the AP 1400 and the first to third STAs 1410, 1420, and 1430 may wait.
  • the AP 1400 of FIG. 14 may transmit the second random trigger frame 1404.
  • the STAs that want to perform the random access procedure in the second cycles T7 to T13 are the first and third STAs 1410 and 1430.
  • the second random trigger frame 1404 may include second allocation information indicating a plurality of resource units (RUs) allocated by the AP 1400.
  • the second allocation information may indicate three resource units RU3, RU4, and RU5.
  • All of the first user identifier fields of the first user-specific field (eg, 960 # 1 of FIG. 9) of the second random trigger frame 1404 may be set to '0'.
  • the first RU allocation field of the first user-specific field may be set to indicate the first resource unit RU3.
  • All of the second user identifier fields of the second user-specific field (eg, 960 # 2 of FIG. 9) of the second random trigger frame 1404 may be set to '0'.
  • the second RU allocation field of the second user-specific field may be set to indicate the fourth resource unit RU4.
  • All of the third user identifier fields of the third user-specific field (eg, 960 # 3 of FIG. 9) of the second random trigger frame 1404 may be set to '0'.
  • the third RU allocation field of the third user-specific field may be set to indicate the fifth resource unit RU5.
  • the first STA 1410 may resume the first countdown operation.
  • the first STA 1410 may update the value v1 "of the first OBO counter to '0' by decreasing the first initial value v1 'maintained at the first OBO counter.
  • the countdown operation can be completed.
  • the first STA 1410 may select one of the RU sets RU3, RU4, and RU5 allocated to the second random trigger frame 1404 as a random resource unit. For example, the first STA 1410 may select the third resource unit RU3 as a random resource unit for transmitting an uplink frame.
  • the third STA 1430 may initiate a third countdown operation.
  • the third STA 1430 may sequentially decrease the third initial value (OBO3) for the third OBO counter by the number '3' of the third to fifth resource units RU3 to RU5. Accordingly, the third count value v3 held in the third OBO count becomes '2'.
  • the eighth section T8-T9 may be SIFS.
  • the first STA 1410 uses the random resource unit to access the second trigger-based frame (HE Trigger-based PPDU_2, 1405) corresponding to the second random trigger frame 1404 (AP). 1400).
  • the second trigger-based frame HE Trigger-based PPDU_2, 1405
  • AP second random trigger frame 1404
  • the tenth section T10-T11 may be SIFS.
  • the first STA 1410 may receive the ACK frame 1406 in response to the second trigger based frame 1405. have.
  • the AP 1400 and the first to third STAs 1410, 1420, and 1430 may wait.
  • the STA that has completed the random access procedure does not receive an ACK frame corresponding to the uplink frame transmitted through the random resource unit, in order to reduce the possibility of collision between the plurality of STAs, the STA that has not received the ACK frame is uplinked. It is possible to exponentially increase the range of OCW for link transmission.
  • exponentially increasing the range of OCW means increasing the counter window CW of the OBO counter to [0, 2 * OCW + 1]. Subsequently, the STA may set a randomly selected value in the increased counter window period as an initial value for the OBO counter.
  • FIG. 15 is a diagram illustrating an OFDMA based random access procedure according to the present embodiment.
  • FIG. 15 is a description of the first to twelfth sections T1-T2 to T12-T13 of FIG. 14, the description of the AP 1400 of FIG. 14, and the first to third STAs 1410 to 1430 of FIG. 14. It will be understood that this can be understood based on the description of.
  • the second STA 1520 completes the second countdown operation.
  • the value v2 ′ updated in the second OBO counter of the second STA 1520 may be '0'.
  • the second STA 1520 may select one of the RU sets RU1 and RU2 allocated through the first random trigger frame 1501 as a random resource unit.
  • the first resource unit RU1 and the second resource unit RU2 may correspond to 26 subcarrier sets.
  • the second STA 1520 may select the second resource unit RU2 as a random resource unit for transmitting an uplink frame.
  • the second period T2-T3 of FIG. 15 may be a short inter-frame space (SIFS).
  • SIFS short inter-frame space
  • the second STA 1520 uses the selected random resource unit RU2 to transmit the first trigger based uplink to be transmitted in response to the first random trigger frame 1501. It is possible to determine whether transmission of the frame (HE Trigger-based PPDU) 1502 is possible.
  • the second STA 1520 in order to determine whether the first trigger-based uplink frame 1502 can be transmitted, the transmission size of the random resource unit (RU2) and the first trigger-based upstream The traffic size of the link frame 1502 can be compared.
  • RU2 random resource unit
  • the transmission size of the random resource unit RU2 may be determined by the STA in advance using a plurality of subcarrier sets corresponding to the random resource unit RU2 (for example, RU2 is a set of 26 subcarriers). It may mean the size of traffic that can be transmitted for a set time.
  • the second STA 1520 may determine that the transmission size of the random resource unit RU2 is smaller than the traffic size of the first trigger based uplink frame 1502. In this case, the second STA 1520 may wait for the transmission of the subsequent random trigger frame 1504 without transmitting the first trigger based uplink frame 1502.
  • the AP 1500 and the first to third STAs 1510 to 1530 may wait.
  • the AP 1500 and the first to third STAs 1510 to 1530 may wait.
  • the AP 1500 of FIG. 15 may transmit a second random trigger frame 1504.
  • the second random trigger frame 1504 may include second allocation information indicating the allocated plurality of resource units (RU).
  • the second allocation information may indicate two resource units RU3 and RU4.
  • the third resource unit RU3 and the fourth resource unit RU4 may correspond to 106 subcarrier sets.
  • the second STA 1520 that has already completed the countdown operation in the previous period T1-T2 skips the subsequent countdown operation according to the reception of the second random trigger frame 1504. You can skip.
  • the second STA 1520 may select one of the third resource unit RU3 and the fourth resource unit RU4 allocated through the second random trigger frame 1504 as the second random resource unit. For example, it is assumed that the second STA 1520 selects the fourth resource unit RU4 as the second random resource unit.
  • An eighth period T8-T9 of FIG. 15 may be a short inter-frame space (SIFS).
  • SIFS short inter-frame space
  • the second STA 1520 uses the selected random resource unit RU4 to transmit a second trigger-based uplink to be transmitted in response to the second random trigger frame 1504. It may be determined whether the frame 1505 can be transmitted.
  • the second trigger based uplink frame 1505 may be understood as a frame including the same information as the first trigger based uplink frame 1502 of the third section T3-T4.
  • the second STA 1520 may transmit the second random resource unit RU4 and the second trigger to determine whether the second trigger-based uplink frame 1505 may be transmitted.
  • the traffic size of the base uplink frame 1505 may be compared.
  • the transmission size of the second random resource unit RU4 may be set by the STA to a plurality of subcarrier sets corresponding to the second random resource unit RU4 (eg, RU4 is 106 subcarrier sets). Using this may refer to the size of the traffic that can be transmitted for a predetermined time.
  • the random resource unit is described as 26 subcarrier sets or 106 subcarrier sets, but it will be understood that the present specification is not limited thereto. That is, the random resource unit may be 52 subcarrier sets or 242 subcarrier sets.
  • the second STA 1520 may determine that a transmission size of the second random resource unit RU4 is larger than a traffic size of the second trigger based uplink frame 1505. have. In this case, the second STA 1520 may transmit the second trigger based uplink frame 1505 to the AP 1500 using the second random resource unit RU4.
  • the tenth section T10-T11 of FIG. 15 may be SIFS.
  • the second STA 1520 transmits an ACK frame 1506 in response to the second trigger-based uplink frame 1505. ) Can be received.
  • the prior art does not clearly disclose a subsequent operation of the STA.
  • the user STA may attempt to retransmit through the subsequent random resource unit selected again based on the subsequent random trigger frame.
  • a plurality of resource units having different sizes may be allocated to the first random trigger frame 1501 or the second random trigger frame 1504.
  • the second STA 1520 may perform a first random operation without considering the size of the allocated resource unit. Any one of the first to third resource units of the trigger frame 1501 may be selected as the random resource unit.
  • the second STA 1520 may consider the size of the allocated resource unit and thus the first random trigger frame.
  • One of the second and third resource units of 1501 may be selected as the random resource unit.
  • each STA may perform a random access procedure by selecting a resource unit according to the size of the uplink frame.
  • the type of trigger-based uplink frame transmitted to the AP through the random access procedure described with reference to FIG. 15 may be limited to a control frame or a management frame.
  • a control frame may be a buffer status report frame sent in response to a buffer status report poll type trigger frame or a buffer status transmitted through a QoS null frame. It may be a reporting frame.
  • the management frame may be understood as the association request frame 1330 or the association response frame 1340 mentioned in FIG. 13.
  • the trigger based uplink frame transmitted to the AP through the random access procedure described with reference to FIG. 15 may be a data frame.
  • the STA cannot transmit the data frame through the random resource unit. That is, the STA may retry transmission of the data frame using the subsequent random resource unit selected again through the subsequent trigger frame.
  • the STA may transmit the divided data frames through the selected random resource unit by dividing the data frame. Can be. The remaining divided data frames may be transmitted using a subsequent random resource unit selected through the subsequent trigger frame.
  • the random access procedure mentioned with reference to FIGS. 14 and 15 may be understood as an operation only for a user STA associated with an AP. That is, only the user STA combined with the AP through the procedure described with reference to FIGS. 12 and 13 may be allocated a resource unit for OFDMA random access from the AP.
  • an STA combined with an AP may transmit a QoS null frame for buffer status reporting using a random resource unit selected through a random trigger frame.
  • the random access procedure may be understood as an operation applicable to un-associated user STAs regardless of whether they are associated with the AP.
  • 16 is a flowchart illustrating an OFDMA based random access procedure according to the present embodiment.
  • a user STA may include a trigger frame (ie, a random trigger frame) including allocation information indicating a plurality of resource units for orthogonal frequency division multiple access (OFDMA) based random access; TR) may be received from the AP.
  • a trigger frame ie, a random trigger frame
  • OFDMA orthogonal frequency division multiple access
  • the user STA may perform a countdown operation.
  • Each user STA may set an initial value to a backoff counter for OFDMA based random access corresponding to each user STA based on a beacon frame periodically received from the AP.
  • the plurality of user STAs may perform an individual countdown operation based on a backoff counter for OFDMA random access corresponding to each user STA.
  • Each user STA may reduce the initial value set in the backoff counter for OFDMA-based random access by the number of resource units for the OFDMA-based random access allocated through the random trigger frame TR received in step S1610. .
  • the user STA may determine whether the countdown operation is completed based on the random trigger frame TR received in operation S1610.
  • the user STA that has completed the countdown operation may be an STA whose backoff counter of the user STA is set to '0' (or updated) through the countdown operation.
  • the procedure ends.
  • the user STA may store a value remaining in the current backoff counter.
  • the user STA may suspend the countdown operation until a subsequent random trigger frame is received.
  • step S1640 When the countdown operation is completed by the user STA, it may enter into step S1640.
  • the user STA may determine, as the first random resource unit, any one of a plurality of resource units for OFDMA-based random access allocated through the random trigger frame TR received in operation S1610.
  • the user STA may determine whether trigger-based uplink frame transmission is possible through the first random resource unit determined in operation S1640. Specifically, the user STA may compare the transmission size of the first random resource unit and the traffic size of the trigger-based uplink frame to be transmitted in response to the random trigger frame (TR).
  • TR random trigger frame
  • the user STA is trigger-based uplink. It can be determined that the link frame cannot be transmitted.
  • the user STA is triggered uplink. It can be determined that the frame can be transmitted.
  • step S1660 may be performed.
  • the user STA may wait to receive a subsequent random trigger frame without transmitting a trigger based uplink frame to be transmitted in response to the random trigger frame (TR).
  • the user STA may determine any one of a plurality of resource units for OFDMA-based random access allocated to the subsequent random trigger frame as the second random resource unit without a subsequent countdown operation for the subsequent random trigger frame.
  • the user STA may retry transmission of the trigger-based uplink frame through the determined second random resource unit.
  • step S1670 may be performed.
  • the user STA may transmit a trigger based uplink frame through the first random resource unit.
  • 17 and 18 illustrate conceptual diagrams of a trigger frame for an OFDMA-based random access procedure according to another embodiment.
  • step S1710 may be understood as a description of step S1610 of FIG. 16.
  • the user STA may perform a countdown operation on valid resource units among the plurality of resource units allocated to the random trigger frame TR.
  • the valid resource unit may indicate a resource unit determined to be idle through a Clear Channel Assessment (CCA) operation or NAV performed based on a physical layer.
  • CCA Clear Channel Assessment
  • each user STA decreases the initial value set in the backoff counter only by the number of valid resource units. You can.
  • the user STA that completes the countdown operation in operation S1730 may determine any one of valid resource units allocated to the random trigger frame TR as a random resource unit.
  • Subsequent steps S1750, S1760, and S1770 of the present exemplary embodiment may be understood based on the description of the above-described steps S1650, S1660, and S1670.
  • each user STA may first compare the transmission sizes of the plurality of resource units for the OFDMA-based random access allocated to the random trigger frame TR and the traffic size of the trigger-based uplink frame.
  • each user STA further determines whether a plurality of resource units for OFDMA-based random access that can accommodate the traffic size (having a size larger than the traffic size) are valid resource units (ie, CCA operation or NAV).
  • the random resource unit for transmission of the trigger-based uplink frame can be determined.
  • each user STA counts for each user STA only if a valid resource unit (that is, an idle resource unit) for transmitting a trigger-based uplink frame exists in the random trigger frame TR. You can also perform the down operation. Furthermore, when the countdown operation is completed, the user STA may determine any one of valid resource units (ie, idle resource units) as a random resource unit.
  • steps S1810 to S1830 may be understood as descriptions of steps S1610 to S1630 of FIG. 16.
  • the user STA may determine whether an uplink frame corresponding to the random trigger frame TR exists through the trigger type field 1060 of the received random trigger frame TR.
  • the buffer status report among a plurality of user STAs that have received a random trigger frame (TR) may perform a countdown operation for selecting a random resource unit.
  • TR buffer status report poll
  • a user STA that does not transmit a buffer status report (BSR) frame may wait until a trigger frame of a basic type is received without performing a countdown operation.
  • BSR buffer status report
  • the trigger type field 1060 of the received random trigger frame is a buffer status reporting poll (BSRP) type or a basic type.
  • BSRP buffer status reporting poll
  • a user STA that wants to transmit a buffer status report (BSR) frame may perform a countdown operation for selecting a random resource unit from a random trigger frame.
  • BSR buffer status report
  • a user STA that wants to transmit a PS-Poll frame for the buffered traffic or an association request (or response) frame transmitted / received in the association step may perform a countdown operation for selecting a random resource unit from the random trigger frame. It can't be done.
  • 19 is a block diagram illustrating a wireless terminal to which an embodiment can be applied.
  • a wireless terminal may be an STA capable of implementing the above-described embodiment and may be an AP or a non-AP STA.
  • the wireless terminal may correspond to the above-described user or may correspond to a transmitting terminal for transmitting a signal to the user.
  • the AP 1900 includes a processor 1910, a memory 1920, and a radio frequency unit 1930.
  • the RF unit 1930 may be connected to the processor 1910 to transmit / receive a radio signal.
  • the processor 1910 may implement the functions, processes, and / or methods proposed herein. For example, the processor 1910 may perform an operation according to the present embodiment described above. The processor 1910 may perform an operation of the AP disclosed in the present embodiment of FIGS. 1 to 18.
  • the non-AP STA 1950 includes a processor 1960, a memory 1970, and a radio frequency unit 1980.
  • the RF unit 1980 may be connected to the processor 1960 to transmit / receive a radio signal.
  • the processor 1960 may implement the functions, processes, and / or methods proposed in the present embodiment.
  • the processor 1960 may be implemented to perform the non-AP STA operation according to the present embodiment described above.
  • the processor 1960 may perform the operation of the non-AP STA disclosed in the present embodiment of FIGS. 1 to 18.
  • Processors 1910 and 1960 may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, data processing devices, and / or converters for interconverting baseband signals and wireless signals.
  • the memory 1920, 1970 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices.
  • the RF unit 1930 and 1980 may include one or more antennas for transmitting and / or receiving a radio signal.
  • Modules may be stored in memory 1920, 1970 and executed by processors 1910, 1960.
  • the memories 1920 and 1970 may be internal or external to the processors 1910 and 1960, and may be connected to the processors 1910 and 1960 by various well-known means.

Landscapes

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

Abstract

L'invention concerne un procédé par lequel un premier terminal sans fil transmet une trame de liaison montante dans un système LAN sans fil, qui comprend les étapes consistant à : recevoir, en provenance d'un second terminal sans fil, une première trame de déclencheur pour un accès aléatoire basé sur OFDMA ; recevoir, en provenance du second terminal sans fil, une seconde trame de déclencheur pour un accès aléatoire basé sur OFDMA sans transmettre une trame de liaison montante basée sur un déclencheur si une première taille de transmission d'une première unité de ressource aléatoire est plus petite qu'une taille de trafic pour la transmission de la trame de liaison montante basée sur le déclencheur ; et transmettre la trame de liaison montante basée sur le déclencheur à une seconde unité de ressource aléatoire.
PCT/KR2017/005664 2016-05-31 2017-05-31 Procédé de transmission d'une trame de liaison montante dans un système lan sans fil, et terminal sans fil utilisant ledit procédé WO2017209501A1 (fr)

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
US201662343150P 2016-05-31 2016-05-31
US62/343,150 2016-05-31
US201662343858P 2016-06-01 2016-06-01
US62/343,858 2016-06-01
US201662344402P 2016-06-02 2016-06-02
US62/344,402 2016-06-02
US201662359216P 2016-07-07 2016-07-07
US62/359,216 2016-07-07

Publications (1)

Publication Number Publication Date
WO2017209501A1 true WO2017209501A1 (fr) 2017-12-07

Family

ID=60478849

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2017/005664 WO2017209501A1 (fr) 2016-05-31 2017-05-31 Procédé de transmission d'une trame de liaison montante dans un système lan sans fil, et terminal sans fil utilisant ledit procédé

Country Status (1)

Country Link
WO (1) WO2017209501A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020022814A1 (fr) * 2018-07-26 2020-01-30 엘지전자 주식회사 Procédé et appareil de réception de données d'ul dans un système lan sans fil
US20220053560A1 (en) * 2020-08-17 2022-02-17 Sony Group Corporation Request trigger frame and txop sharing launched by non-ap sta
WO2023197323A1 (fr) * 2022-04-15 2023-10-19 北京小米移动软件有限公司 Procédé et appareil de mesure de détection de wlan, dispositif électronique et support de stockage

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150073165A (ko) * 2012-10-16 2015-06-30 엘지전자 주식회사 무선랜에서 채널 액세스 방법 및 장치
WO2016028117A1 (fr) * 2014-08-21 2016-02-25 엘지전자 주식회사 Procédé et appareil de déclenchement de données en liaison montante dans un réseau local (lan) sans fil

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150073165A (ko) * 2012-10-16 2015-06-30 엘지전자 주식회사 무선랜에서 채널 액세스 방법 및 장치
WO2016028117A1 (fr) * 2014-08-21 2016-02-25 엘지전자 주식회사 Procédé et appareil de déclenchement de données en liaison montante dans un réseau local (lan) sans fil

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
KHOROV, EVGENY ET AL.: "Considerations on Trigger Frame for Random Access Procedure", IEEE 802, vol. 1 1 -16, 15 March 2016 (2016-03-15), pages 0399r1, XP055446031 *
KHOROV, EVGENY ET AL.: "Random Access RU Allocation in the Trigger Frame", IEEE 802.1 1-16/0582R3, 17 May 2016 (2016-05-17), XP055445991 *
LANANTE, LEONARDO ET AL.: "Random Access UL MU Resource Allocation an d Indication", IEEE 802. 11-16/0340R1, 14 March 2015 (2015-03-14), XP068105209 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020022814A1 (fr) * 2018-07-26 2020-01-30 엘지전자 주식회사 Procédé et appareil de réception de données d'ul dans un système lan sans fil
US11632797B2 (en) 2018-07-26 2023-04-18 Lg Electronics Inc. Method and apparatus for receiving UL data in wireless LAN system
US20220053560A1 (en) * 2020-08-17 2022-02-17 Sony Group Corporation Request trigger frame and txop sharing launched by non-ap sta
WO2023197323A1 (fr) * 2022-04-15 2023-10-19 北京小米移动软件有限公司 Procédé et appareil de mesure de détection de wlan, dispositif électronique et support de stockage

Similar Documents

Publication Publication Date Title
WO2020045891A1 (fr) Procédé et dispositif destinés à établir une transmission commune dans un système de réseau local sans fil
WO2017026782A1 (fr) Procédé et dispositif destinés à la formation d'un champ de commande comprenant des informations sur des unités de ressource dans un système lan sans fil
WO2017026784A1 (fr) Procédé et dispositif permettant de former un signal de commande comprenant un champ de commande dans un système de réseau local (lan) sans fil
WO2017074070A1 (fr) Procédé de transmission de trames de liaison montante d'utilisateurs multiples dans un système de réseau local sans fil
WO2019203626A1 (fr) Procédé et dispositif pour l'exécution d'une communication via un accès de liaison montante dans un système lan sans fil
WO2016195402A1 (fr) Procédé d'exploitation en mode d'économie d'énergie dans un système lan sans fil et appareil associé
WO2016072766A1 (fr) Procédé et dispositif d'attribution d'unité de ressource sur la base d'un conteneur dans un lan sans fil
WO2017119759A1 (fr) Procédé pour une gestion de puissance et terminal utilisant ledit procédé dans un système lan sans fil
WO2017069534A1 (fr) Procédé de transmission de trame de déclenchement dans un système lan sans fil, et terminal l'utilisant
WO2020022814A1 (fr) Procédé et appareil de réception de données d'ul dans un système lan sans fil
WO2016175517A1 (fr) Procédé et dispositif d'établissement de communication à l'aide d'une pluralité de techniques d'agencement de ressources dans un système de réseau local sans fil
WO2017183870A2 (fr) Procédé de transmission de trame sur la base d'un accès aléatoire dans un système lan sans fil, et terminal sans fil associé
WO2016056830A1 (fr) Procédé et appareil de transmission de données sur une unité de ressources comprenant une tonalité pilote dans un wlan
WO2017183868A1 (fr) Procédé de transmission en liaison montante et terminal sans fil utilisant ce procédé dans un système lan sans fil
WO2016137201A1 (fr) Procédé et dispositif de transmission de signal en utilisant une unité de ressource incluant une pluralité de sous-porteuses
WO2019225986A1 (fr) Procédé et dispositif de transmission et de réception de ppdu sur la base d'un fdd dans un système lan sans fil
WO2017142357A1 (fr) Procédé de transmission en liaison montante dans un système de réseau local sans fil et terminal sans fil utilisant ce dernier
WO2016159737A1 (fr) Procédé et dispositif de configuration de champ de signal dans un système lan sans fil
WO2016182415A1 (fr) Procédé de fonctionnement en mode d'économie d'énergie dans un système lan sans fil et appareil s'y rapportant
WO2016085286A1 (fr) Procédé et dispositif pour la transmission de données sur la base de différents modèles de tonalité pilote dans un réseau lan sans fil
WO2017030428A1 (fr) Procédé de communication sans fil utilisant des informations de commande, et terminal de communication sans fil
WO2017074025A1 (fr) Procédé de réception de données dans un système lan sans fil, et terminal l'utilisant
WO2018084404A1 (fr) Procédé et dispositif de réutilisation spatiale, pour transmettre une ppdu dans un système lan sans fil
WO2020050541A1 (fr) Procédé et dispositif pour transmettre une trame dans un système lan sans fil
WO2019009596A1 (fr) Procédé de transmission de trame basé sur de multiples canaux canalisés dans un système lan sans fil et terminal sans fil utilisant ledit procédé

Legal Events

Date Code Title Description
NENP Non-entry into the national phase

Ref country code: DE

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

Ref document number: 17806994

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 17806994

Country of ref document: EP

Kind code of ref document: A1