WO2017119759A1 - Procédé pour une gestion de puissance et terminal utilisant ledit procédé dans un système lan sans fil - Google Patents

Procédé pour une gestion de puissance et terminal utilisant ledit procédé dans un système lan sans fil Download PDF

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Publication number
WO2017119759A1
WO2017119759A1 PCT/KR2017/000189 KR2017000189W WO2017119759A1 WO 2017119759 A1 WO2017119759 A1 WO 2017119759A1 KR 2017000189 W KR2017000189 W KR 2017000189W WO 2017119759 A1 WO2017119759 A1 WO 2017119759A1
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frame
twt
sta
uplink
twt service
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PCT/KR2017/000189
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English (en)
Korean (ko)
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박현희
류기선
김정기
조한규
김서욱
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엘지전자 주식회사
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Publication of WO2017119759A1 publication Critical patent/WO2017119759A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02—Power saving arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA
    • 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]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • the present disclosure relates to wireless communication, and more particularly, to a method for power management in a WLAN system and a terminal using the same.
  • WLAN wireless local area network
  • the portable terminal may be a personal digital assistant (PDA), a laptop, a portable multimedia player (PMP).
  • PDA personal digital assistant
  • PMP portable multimedia player
  • communication between terminals in a WLAN system is performed through a management entity such as a base station or an access point.
  • the management medium is responsible for scheduling for data communication.
  • NAN is a standard established by the Wi-Fi Alliance (WFA) based on the Wi-Fi standard.
  • WFA Wi-Fi Alliance
  • the NAN specification provides for synchronization and discovery procedures between devices in the 2.5 GHz or 5 GHz frequency band.
  • An object of the present specification is to provide a method for power management to reduce power consumption in a WLAN system and a terminal using the same.
  • a user station may include contention window information for a backoff counter of orthogonal frequency division multiple access (OFDMA) based random access and a service period for OFDMA based random access.
  • OFDMA orthogonal frequency division multiple access
  • Receiving a beacon frame containing the start time information of the AP from the access point the user STA receives a reference trigger frame from the AP in the service interval based on the start time information
  • the reference trigger frame includes allocation information indicating a plurality of resource units and quantity information on the total number of resource units to be transmitted to the STA during the service interval. Transition from an awake state to a doze state based on the second value set in the backoff counter according to the first value and the contention window information Determining whether.
  • a method for power management to reduce power consumption in a WLAN system and a 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.
  • FIG. 9 shows an example of a trigger frame.
  • FIG 11 shows an example of subfields included in individual user information fields.
  • FIG. 12 is a diagram illustrating power management of a WLAN system according to an embodiment of the present disclosure.
  • FIG. 13 is a diagram illustrating power management of a WLAN system according to another embodiment of the present disclosure.
  • FIG. 14 is a diagram illustrating power management of a WLAN system according to another embodiment of the present disclosure.
  • 15 is a diagram illustrating power management of a WLAN system according to another embodiment of the present disclosure.
  • 16 is a view showing power management of a WLAN system using a reply frame according to an embodiment of the present disclosure.
  • 17 is a diagram illustrating power management of a WLAN system using a reply frame according to another embodiment of the present specification.
  • FIG. 18 is a diagram illustrating power management of a WLAN system in a plurality of TWT service intervals according to an embodiment of the present disclosure.
  • 19 is a diagram illustrating power management of a WLAN system in a plurality of TWT service intervals according to another embodiment of the present disclosure.
  • 20 is a diagram illustrating power management of a WLAN system using a plurality of trigger frames in a TWT service interval according to an embodiment of the present disclosure.
  • 21 is a flowchart illustrating power management of a WLAN system according to an embodiment of the present disclosure.
  • 22 is a block diagram illustrating a wireless terminal to which an embodiment of the present specification 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.
  • the second BSS 105 may include a second AP 130 and one or more STAs 105-1, 105-2.
  • 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 may be used for 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 of 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.
  • orthogonal frequency division multiple access (OFDMA) based transmission method is preferably 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
  • a plurality of STAs 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 illustrating an example of HE-SIG-B.
  • 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. 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 illustrates an example of subfields included in an individual user information field. 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) to which per user information corresponds.
  • An example of the identifier may be all or part of an AID. have.
  • 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 diagram illustrating power management of a WLAN system according to an embodiment of the present disclosure.
  • the AP and the STA referred to herein are assumed to operate on a contention basis.
  • the AP of the present specification may periodically transmit a beacon frame (hereinafter, referred to as 'BF').
  • the period of the beacon frame BF may be 100 ms (millisecond).
  • a time interval between periodically transmitted beacon frames may be referred to as a beacon interval.
  • the time intervals T0 to T5 between the first beacon frame BF1 and the second beacon frame BF2 of FIG. 12 may be referred to as a first beacon interval.
  • the beacon frame of the present specification may include various elements as described in Section 9.3.3.3 of the standard document 802.11 REVmc / D8.0.
  • the beacon frame herein may include a TWT element disclosed in Section 9.4.200 of the standard document 802.11ax / D1.0.
  • the beacon frame of the present specification is transmitted in a broadcast scheme.
  • the STA of the present specification operates in a power save mode (hereinafter, referred to as a 'PS mode').
  • the STA operating in the PS mode may be in an awake state or a doze state. That is, the STA operating in the PS mode may transition from the awake state to the sleep state or transition from the sleep state to the awake state.
  • the STA in the awake state may transmit a frame to the AP or receive a frame transmitted from the AP.
  • the STA in sleep mode cannot transmit a frame to the AP and cannot receive a frame transmitted from the AP.
  • the STA operating in the PS mode may switch from the awake state to the sleep state after receiving the beacon frame and maintain the sleep state at the beacon interval in order to reduce power consumption.
  • the STA operating in the PS mode may maintain a sleep state until a subsequent beacon frame is received.
  • the STA operating in the PS mode may switch to the awake state in a specific period of the beacon interval, and may receive data buffered in the AP or transmit data buffered in the STA to the AP.
  • a specific period may be referred to herein as a target awake time (TWT) service period or broadcast TWT service period during which the STA is awake.
  • TWT target awake time
  • broadcast TWT service period during which the STA is awake.
  • a section that is not a TWT service interval among the beacon intervals may be referred to as a TWT non-service period in which the STA is in sleep.
  • the horizontal axis of the AP 1210 refers to the time t1 of the AP view, and the vertical axis of the AP 1210 is related to the presence or absence of a frame transmitted by the AP.
  • the horizontal axis of the STA 1220 means time t2 from the viewpoint of the STA, and the vertical axis of the STA 1220 is associated with the presence or absence of a frame transmitted by the STA.
  • the AP 1210 and the STA 1220 may perform channel competition for obtaining a transmission opportunity (hereinafter, referred to as 'TXOP') for the channel.
  • 'TXOP' a transmission opportunity
  • the AP 1210 and the STA 1220 of FIG. 12 may perform channel competition based on EDCA (Enhanced Distributed Channel Access).
  • EDCA Enhanced Distributed Channel Access
  • the AP 1210 winning the channel competition may obtain a TXOP. Accordingly, the AP 1210 may transmit the first beacon frame BF1.
  • the first beacon frame transmitted in the second period T1 to T2 may include a TWT element.
  • the first beacon frame BF1 of FIG. 12 may include a TWT parameter set for a TWT service interval.
  • the TWT parameter set includes TWT service interval start time information for the TWT service interval, duration information of the TWT service interval, and a plurality of TWT service intervals in the beacon interval.
  • interval information of the TWT service interval may be included.
  • the TWT parameter set for the TWT non-service interval is not included in the beacon frame.
  • the remaining sections other than the TWT service interval indicated by the TWT parameter set within one beacon interval may be understood as the TWT non-service interval.
  • the recommended frame of the present specification indicates a frame that the AP or STA can transmit in the TWT service period.
  • the AP or STA may transmit only a recommendation frame.
  • an acceptance group may mean a set of recommended frames.
  • the beacon frame of the present specification may include a TWT flow identifier (TWT FID) indicating a grant group of a recommendation frame.
  • TWT FID TWT flow identifier
  • the TWT flow identifier (TWT FID) according to the present embodiment may be set to indicate one of the first to third allowed groups.
  • TWT flow identifier (TWT FID) of the present specification may be set as shown in Table 1 below.
  • an allowance group according to an embodiment of the present disclosure may be classified into three groups according to a TWT flow identifier (TWT FID).
  • TWT FID TWT flow identifier
  • the first grant group is a case where the TWT flow identifier (TWT FID) is '0'.
  • TWT FID TWT flow identifier
  • the STA may transmit all kinds of frames without limiting the frames that can be transmitted in the TWT service interval.
  • the second allowed group is a case where the TWT flow identifier (TWT FID) is '1'.
  • TWT FID TWT flow identifier
  • the STA may receive a power-save poll frame, a quality of service null frame, A frame associated with sounding feedback and a management frame may be transmitted.
  • TWT FID TWT flow identifier
  • the third allowed group is a case where the TWT flow identifier (TWT FID) is '2'.
  • TWT FID TWT flow identifier
  • the STA may transmit a power-save poll frame, a QoS null frame, a QoS null frame in the TWT service interval, A frame associated with sounding feedback and a management frame may be transmitted.
  • the AP may not transmit a trigger frame including at least one resource unit for random access for a random access procedure.
  • the STA that has received the beacon frame in which the TWT FID is set to '1' cannot transmit a frame associated with random access.
  • TWT flow identifier TWT FID of the first beacon frame BF1 in the second sections T1 to T2 is set to '1'.
  • the STA 1220 of FIG. 12 may receive the first beacon frame BF1 in an awake state.
  • the STA 1220 may operate based on a plurality of elements included in the received first beacon frame BF1.
  • the STA 1220 of FIG. 12 may obtain information about a start time and a duration of a TWT service interval (TWT SP) based on the TWT parameter set included in the first beacon frame BF1.
  • TWT SP TWT service interval
  • the STA 1220 of FIG. 12 is based on the TWT flow identifier (TWT FID) included in the first beacon frame (BF1) of the frame that the STA 1220 can transmit to the AP in the TWT service interval (TWT SP).
  • TWT FID TWT flow identifier
  • the type that is, information about an allowable group of a recommendation frame (for example, when the TWT FID is '1') may be obtained.
  • the STA 1220 may switch from an awake state to a doze state after receiving the first beacon frame BF1. For example, the STA 1220 may maintain a sleep state during the third periods T2 to T3.
  • the STA 1220 may switch from the sleep state to the awake state at the start time T3 of the TWT service section TWT SP according to the TWT parameter set. have.
  • the STA 1220 may maintain an awake state during the TWT service intervals (TWT SP, T3 to T4).
  • the STA 1220 may determine whether the uplink frame for the AP is a recommendation frame allowed in the TWT service interval (TWT SP).
  • TWT SP TWT service interval
  • the uplink frame of FIG. 12 may be a data frame (UL DATA).
  • the STA 1220 may determine whether to transmit the uplink frame to the AP 1210 according to whether the uplink frame for the AP 1210 is a recommended frame.
  • the STA 1220 may perform an enhanced distributed channel access (EDCA) backoff procedure in a TWT service interval (TWT SP). That is, if there is no constraint of a frame transmitted by the STA according to the TWT FID (TWT FID) (for example, if the TWT FID is '0'), the STA that has completed the EDCA backoff operation may perform an uplink data frame. It will be appreciated that it can be transmitted.
  • EDCA enhanced distributed channel access
  • the STA 1220 may determine that an uplink frame (eg, a data frame) for the AP 1210 is not a recommendation frame according to Table 1. Based on the above determination, the STA 1220 according to the present embodiment may determine not to transmit an uplink frame in a TWT service interval (TWT SP).
  • TWT SP TWT service interval
  • the process of determining whether the uplink frame is the recommended frame and the process of determining whether to transmit the uplink frame according to the determination result may be performed in another section (for example, the first section in which the beacon frame is received).
  • the STA 1220 may switch from an awake state to a doze state.
  • the fifth section T4 to T5 may be referred to as a TWT non-SP section.
  • the STA 1220 may switch back to an awake state at the start time T5 of the second beacon interval for the second beacon frame BF2 after the first beacon intervals T0 to T5 have elapsed. have. It will then be appreciated that the aforementioned operation may be repeated during subsequent beacon intervals.
  • FIG. 12 illustrates that the STA intends to provide to the AP in the TWT service interval (TWT SP) when there are constraints according to the TWT flow identifier (that is, the TWT FID is '1' or '2'). It will be appreciated that the frame may be applied in a variety of situations that conflict with restrictions by the TWT Flow Identifier (TWT FID).
  • a power management state (eg, an awake state or a sleep state) of an STA operating in a power save mode (PS mode) based on constraints on a TWT flow identifier, as compared with the related art.
  • PS mode power save mode
  • a technique for improved power management for an STA may be provided.
  • FIG. 13 is a diagram illustrating power management of a WLAN system according to another embodiment of the present disclosure.
  • the STA 1320 may access a buffer status report (BSR) frame in the AP. May transmit to 1310.
  • BSR buffer status report
  • the buffer status report (BSR) frame may be transmitted as a quality of service null frame. More details on Buffer Status Report (BSR) frames are described in Section 9.2.4.6.4.5 of the standard document 802.11ax / D1.0.
  • the STA 1320 may determine the buffer status report (BSR) frame as a recommendation frame according to Table 1.
  • FIG. 13 illustrates a case where the TWT flow identifier (TWT FID) is set to '1', so that the STA 1320 may transmit a buffer status report (BSR) frame to the AP 1310.
  • the frames that the AP 1310 can provide for the STA 1320 in the TWT service interval (TWT SP) may include all frames except the trigger frame for random access.
  • the AP 1310 may transmit an acknowledgment (ACK) frame in response to the buffer status report (BSR) frame.
  • ACK acknowledgment
  • BSR buffer status report
  • the STA 1320 may determine whether the uplink frame for the AP 1310 is a recommendation frame allowed in the TWT service interval (TWT SP). For example, the STA 1320 of FIG. 13 may determine whether a data frame (UL DATA) for the AP 1310 is a recommended frame. According to the determination result, the STA 1320 may determine whether to transmit a data frame (UL DATA) to the AP 1310.
  • TWT SP TWT service interval
  • the STA 1320 may determine that an uplink frame (eg, a data frame) for the AP 1310 is not a recommendation frame according to Table 1. According to the above determination, the STA 1320 according to the present embodiment may determine not to transmit an uplink frame in a TWT service interval (TWT SP).
  • TWT SP TWT service interval
  • a buffer status report (BSR) frame may be referred to as a first uplink frame.
  • the data frame (UL DATA) is not actually transmitted by the STA, but may be referred to as a second uplink frame since the STA performs a determination process according to the present specification.
  • 14 is a diagram illustrating power management of a WLAN system according to another embodiment of the present disclosure. 14 assumes a multi-user (MU) situation in which a plurality of STAs 1410 and 1420 exist.
  • MU multi-user
  • the horizontal axis of the AP 1410 refers to the time t1 of the AP view, and the vertical axis of the AP 1410 is associated with the presence or absence of a frame transmitted by the AP.
  • the horizontal axis of the first STA 1420 of FIG. 14 refers to a time t2 from the perspective of the first STA, and the vertical axis of the first STA 1420 is associated with the existence of a frame transmitted by the first STA.
  • the horizontal axis of the second STA 1430 of FIG. 14 means a time t3 from the viewpoint of the second STA, and the vertical axis of the second STA 1430 is associated with the presence or absence of a frame transmitted by the second STA. .
  • the AP 1410 may acquire TXOP by winning through channel competition.
  • the AP 1410 acquiring the TXOP may transmit a trigger frame (TF).
  • the trigger frame TF of FIG. 14 may be a trigger frame of a buffer status report poll (BSRP) type. Further details on trigger frames are disclosed in Section 9.3.1.23 of the standard document 802.11ax / D1.0.
  • the first and second STAs 1420 and 1430 may transmit the first and second buffer status report frames BSR1 and BSR2 to the AP 1410 in response to the trigger frame TF.
  • the first and second buffer status report frames BSR1 and BSR2 may be transmitted as QoS null (Quality of Service Null) frames.
  • the AP 1410 may transmit a block reply (BA) frame in response to the first and second buffer status report frames BSR1 and BSR2.
  • BA block reply
  • the first STA 1420 determines that the uplink frame (for example, the first data frame UL DATA1) for the AP 1410 is not a recommendation frame according to Table 1. can do.
  • the second STA 1430 may determine that an uplink frame (for example, the second data frame UL DATA2) for the AP 1410 is not a recommendation frame according to Table 1.
  • the first and second STAs 1420 and 1430 determine not to transmit the first and second uplink frames UL DATA1 and UL DATA2 in the TWT service interval (TWT SP). Can be.
  • 15 is a diagram illustrating power management of a WLAN system according to another embodiment of the present disclosure.
  • the AP 1510, the first STA 1520, and the second STA 1530 of FIG. 15 are the AP 1410, the first STA 1420, and the second STA (FIG. 14) of FIG. 14. 1430).
  • the first beacon frame BF1 transmitted in the second sections T1 to T2 of FIG. 15 is not only the viewpoint of the TWT element described with reference to FIGS. 12 to 14 but also a traffic indication map. Indication Map, hereinafter, 'TIM') may be further specified in view of information.
  • Traffic indication map (TIM) information herein may be used by the AP. That is, the AP may signal the presence or absence of traffic buffered in the AP through the traffic indication map (TIM) information for the STA operating in the power save (PS) mode.
  • TIM traffic indication map
  • an STA having a defect with the AP may be assigned association ID (FID) information from the AP.
  • Association ID (AID) information assignable by the AP may be '1' through '2007'.
  • the AP may allocate '1' to a position corresponding to the combined STA of the traffic indication map (TIM) information, and otherwise assign '0'. .
  • the presence of the buffered traffic for the second STA of FIG. 15 may be signaled through traffic indication map (TIM) information included in the first beacon frame BF1.
  • TIM traffic indication map
  • TWT flow identifier (TWT FID) according to another embodiment of the present specification may be set as shown in Table 2 below.
  • the TWT flow identifier TWT FID of the first beacon frame BF1 of FIG. 15 is set to '1'. Accordingly, there is a restriction on the type of frame that the STA that has received the first beacon frame BF1 of FIG. 15 can transmit for the AP.
  • TWT FID TWT flow identifier
  • BSR buffer status report
  • TWT FID TWT flow identifier
  • BSR buffer status report
  • the first STA 1520 may transmit a buffer status report (BSR) frame to the AP 1510 based on the EDCA backoff operation. Subsequently, the AP 1510 may transmit an ACK frame in response to the buffer status report (BSR) frame.
  • BSR buffer status report
  • the first STA 1520 may determine that an uplink frame (UL DATA) for the AP 1510 is not a recommendation frame according to Table 2. According to the above determination, the first STA 1520 according to the present embodiment may determine not to transmit an uplink frame (UL DATA) in the TWT service interval (TWT SP).
  • TWT SP TWT service interval
  • the second STA 1530 may maintain an awake state in the fourth period T3 to T4 to receive buffered traffic for the second STA 1530 according to the traffic indication map (TIM) information.
  • TIM traffic indication map
  • the first STA 1520 is an awake state at the end point of the TWT service section (TWT SP) (that is, the start point of the fifth section). Can be switched to the doze state. Subsequently, the first STA 1520 may maintain a sleep state for the fifth period T4 to T5.
  • the second STA 1530 may maintain an awake state to receive downlink data frames (DL DATA) to be transmitted from the AP 1510 even after the end time T4 of the TWT service interval (TWT SP). have.
  • DL DATA downlink data frames
  • FIG. 16 is a view showing power management of a WLAN system using a reply frame according to an embodiment of the present disclosure.
  • FIG. 16 assumes a multi-user (MU) situation in which a plurality of STAs 1610 and 1620 exist.
  • MU multi-user
  • the AP 1610, the first STA 1620, and the second STA 1630 of FIG. 16 include the AP 1410, the first STA 1420, and the second STA (FIG. 14) of FIG. 14. 1430).
  • the trigger frame TF transmitted in the fourth section T3 to T4 of FIG. 16 may be a trigger frame of a buffer status report poll (BSRP) type like the trigger frame described with reference to FIG. 14.
  • BSRP buffer status report poll
  • the block reply (BA) frame transmitted in the fourth section T3 to T4 of FIG. 16 may further include additional information provided to the AP 1610.
  • the additional information of FIG. 16 may be a scheduling indicator (SI).
  • SI scheduling indicator
  • the AP 1610 of FIG. 16 determines whether there is a section capable of scheduling in the beacon intervals T0 to T5 corresponding to the first beacon frame BF1. It can indicate whether or not.
  • Each of the STAs 1620 and 1630 of FIG. 16 has a TWT flow identifier (TWT FID) '1' as shown in FIG. 14 in the TWT service intervals (TWT SP, T3 to T4), and thus is transmitted by the STA according to Table 1.
  • TWT FID TWT flow identifier
  • each STA 1620 and 1630 after the TWT service interval are awake state. Can be maintained.
  • each STA 1620 and 1630 after the TWT service interval may set a doze state. I can keep it.
  • an AP collectively signals information of a scheduling indicator (SI) included in a block reply (BA) frame to a plurality of STAs.
  • SI scheduling indicator
  • BA block reply
  • the present disclosure is not limited thereto, and it is to be understood that the AP of the present disclosure may individually signal information of a scheduling indicator (SI) included in a block reply (BA) frame to each STA.
  • FIG. 17 is a diagram illustrating power management of a WLAN system using a reply frame according to another embodiment of the present specification.
  • FIG. 17 assumes a multi-user (MU) situation in which a plurality of STAs 1710 and 1720 exist.
  • MU multi-user
  • the AP 1710, the first STA 1720, and the second STA 1730 of FIG. 17 include the AP 1410, the first STA 1420, and the second STA (FIG. 14) of FIG. 14. 1430).
  • the trigger frame TF transmitted in the fourth sections T3 to T4 of FIG. 17 may be a trigger frame of a buffer status report poll (BSRP) type like the trigger frame described with reference to FIG. 14.
  • BSRP buffer status report poll
  • the block reply (BA) frame transmitted in the fourth period T3 to T4 of FIG. 17 may further include additional information provided to the AP 1710.
  • the additional information of FIG. 17 may be start time information.
  • the AP 1710 of FIG. 17 transmits to the AP 1610 at the beacon intervals T0 to T5 corresponding to the first beacon frame BF1. By doing so, the start time of the section which can be scheduled may be individually indicated.
  • a block reply (BA) frame includes first start time information (start time1) for the first STA 1720 and second start time information (start time2) for the second STA 1730. can do.
  • each of the STAs 1720 and 1730 of FIG. 17 has a TWT flow identifier (TWT FID) '1' as shown in FIG. 14 in the TWT service intervals (TWT SP, T3 to T4), it is transmitted by the STA according to Table 1 There is a limitation of the frame. That is, each of the STAs 1720 and 1730 of FIG. 17 may not transmit data frames UL DATA1 and UL DATA2 for the AP 1710 in the TWT service intervals TWT SP and T3 to T4.
  • the first STA 1720 and the second STA 1730 may switch from the awake state to the sleep state.
  • the first STA 1720 may switch from the sleep state to the awake state at the time point T5 indicated by the first start time information (start time1).
  • the first STA 1720 in the awake state may transmit the data frame UL DATA1 to the AP 1710 through an EDCA backoff operation. Subsequently, the first STA 1720 that successfully transmits the data frame UL DATA1 may receive an ACK frame from the AP 1710.
  • the first STA 1720 of FIG. 17 may switch to a sleep state and maintain a sleep state for the remaining beacon interval. Alternatively, the first STA 1720 may maintain an awake state for the remaining beacon intervals.
  • the second STA 1730 may switch from the sleep state to the awake state at the time point T6 indicated by the second start time information (start time2).
  • the second STA 1730 in the awake state may transmit the data frame UL DATA2 to the AP 1710 through an EDCA backoff operation. Subsequently, the second STA 1730 that successfully transmits the data frame UL DATA2 may receive an ACK frame from the AP 1710.
  • the second STA 1730 of FIG. 17 may switch to a sleep state and maintain a sleep state for the remaining beacon interval. Alternatively, the second STA 1730 may maintain an awake state for the remaining beacon intervals.
  • 18 is a diagram illustrating power management of a WLAN system in a plurality of TWT service intervals according to an embodiment of the present disclosure. 18 illustrates a case where the TWT flow identifiers (TWT FIDs) set in the plurality of TWT service intervals are the same during the beacon interval corresponding to the first beacon frame.
  • TWT FIDs TWT flow identifiers
  • the first and the first beacon frames BF1 transmitted by the AP 1810 may be included. It is assumed that the second TWT flow identifiers TWT FID1 and TWT FID2 are both set to '1'.
  • the STA 1820 of FIG. 18 may receive the first beacon frame BF1 in an awake state.
  • the STA 1820 may operate based on a plurality of elements included in the received first beacon frame BF1.
  • the STA 1820 of FIG. 18 may obtain information associated with a plurality of TWT service intervals (TWT SPs) based on a TWT parameter set included in the first beacon frame BF1.
  • TWT SPs TWT service intervals
  • the STA 1820 may include start time information of the first TWT service section (TWT SP1), duration information of the first TWT service section (TWT SP1), and a second TWT service section (TWT) based on the TWT parameter set.
  • Start time information of the SP2 duration information of the second TWT service section (TWT SP2), and interval information between the first TWT service section (TWT SP1) and the second service section (TWT SP2) may be obtained.
  • the STA 1820 of FIG. 18 allows the recommendation frame in the first TWT service interval TWT SP1 based on the first TWT flow identifier TWT FID1 included in the first beacon frame BF1. Information about the group can be obtained.
  • the STA 1820 may obtain information about the grant group of the recommended frame based on the second TWT flow identifier (TWT FID2) included in the first beacon frame BF1.
  • TWT FID2 second TWT flow identifier
  • TWT FID1 and TWT FID2 are '1'
  • TWT SP1 and TWT SP2 the types of frames transmitted by the STA in each TWT service interval
  • the STA 1820 may switch from an awake state to a doze state after receiving the first beacon frame BF1.
  • the STA 1820 may maintain a sleep state in the third section T2 to T3.
  • the STA 1820 may switch from the sleep state to the awake state at the start time T3 of the first TWT service period TWT SP1 based on the TWT parameter set.
  • the STA 1820 may maintain an awake state during the first TWT service periods TWT SP1 and T3 to T4.
  • the STA 1820 of FIG. 18 may determine whether an uplink frame for the AP 1810 is a recommendation frame allowed in a TWT service interval (TWT SP).
  • TWT SP TWT service interval
  • the uplink frame of FIG. 18 may be a data frame (UL DATA).
  • the STA 1820 may determine whether to transmit the uplink frame to the AP 1810 according to whether the uplink frame for the AP 1810 is a recommended frame.
  • the STA 1820 may perform an enhanced distributed channel access (EDCA) backoff procedure in a TWT service interval (TWT SP). That is, if there is no constraint of a frame transmitted by the STA according to the TWT FID (TWT FID) (for example, if the TWT FID is '0'), the STA that has completed the EDCA backoff operation may perform an uplink data frame. It will be appreciated that it can be transmitted.
  • EDCA enhanced distributed channel access
  • the STA 1820 may transmit a buffer status report (BSR) frame including OoS information of an uplink frame for the AP 1810. Subsequently, the STA 1820 may receive an ACK frame from the AP 1810 in response to the buffer status report (BSR) frame.
  • BSR buffer status report
  • the STA 1820 may determine that an uplink frame (eg, a data frame (UL DATA)) for the AP 1810 is not a recommendation frame according to Table 1.
  • an uplink frame eg, a data frame (UL DATA)
  • UL DATA data frame
  • the STA 1820 does not transmit an uplink frame (for example, UL DATA) in the first TWT service interval (TWT SP1). Furthermore, the STA 1820 of FIG. 18 may not transmit an uplink frame (eg, a data frame) in a second TWT service interval (TWT SP2) according to a second TWT flow identifier (that is, TWT FID2 is '1'). Can be determined in advance.
  • TWT FID2 is '1'
  • the STA 1820 of FIG. 18 may switch from the awake state to the sleep state at the end time T4 of the first TWT service interval TWT SP1. Subsequently, the STA 1820 may maintain a sleep state for the remaining beacon intervals T4 to T7.
  • the STA 1820 may switch back to the awake state at the start time T7 of the second beacon interval for the second beacon frame BF2 after the first beacon intervals T0 to T7 have elapsed. have.
  • the AP 1810 is included in the second beacon frame BF2 by reflecting information (for example, BSR frame) collected from the STA 1820 at the beacon intervals T0 to T7 corresponding to the first beacon frame BF1. You can organize the information. For example, for the frame (UL DATA) buffered by the STA 1820, the AP 1810 may set the TWT flow identifier (TWT FID) to '0' so that the recommendation frame is not limited.
  • TWT FID TWT flow identifier
  • FIG. 19 is a diagram illustrating power management of a WLAN system in a plurality of TWT service intervals according to another embodiment of the present disclosure.
  • 18 illustrates a case where a TWT flow identifier (TWT FID) set in a plurality of TWT service intervals is different during a beacon interval corresponding to the first beacon frame.
  • TWT FID TWT flow identifier
  • the STA 1920 of FIG. 19 may obtain information associated with the plurality of TWT service periods TWT SP based on the received first beacon frame BF1.
  • the STA 1920 may determine starting point information of the first TWT service section TWT SP1, duration information of the first TWT service section TWT SP1, and a second TWT service section TWT based on the TWT parameter set. Start time information of the SP2), duration information of the second TWT service section (TWT SP2), and interval information between the first TWT service section (TWT SP1) and the second service section (TWT SP2) may be obtained.
  • the STA 1920 constraints the types of frames transmitted by the STA in the first TWT service interval TWT SP1 according to the first TWT flow identifier (that is, the TWT FID1 is '1'). You can judge that this exists. Further, the STA 1920 does not have constraints on the type of frames transmitted by the STA in the second TWT service interval (TWT SP2) according to the second TWT flow identifier (that is, the TWT FID2 is '0'). You can judge that.
  • the STA 1920 may transmit a buffer status report (BSR) frame including OoS information of an uplink frame for the AP 1910 in the first TWT service interval (TWT SP1). Subsequently, the STA 1920 may receive an ACK frame from the AP 1810 in response to the buffer status report (BSR) frame.
  • BSR buffer status report
  • the STA 1920 may determine that an uplink frame (eg, a data frame (UL DATA)) for the AP 1910 is not a recommendation frame according to Table 1.
  • an uplink frame eg, a data frame (UL DATA)
  • UL DATA data frame
  • the STA 1920 does not transmit an uplink frame (for example, UL DATA) in the first TWT service interval (TWT SP1). Accordingly, the STA 1920 of FIG. 19 may switch from the awake state to the sleep state at the end time T4 of the first TWT service period TWT SP1.
  • an uplink frame for example, UL DATA
  • the STA 1920 may maintain a sleep state for the fifth section T4 to T5.
  • the STA 1920 may switch from the sleep state to the awake state at a time point T5 when the value of the TWT flow indicator TWT FID assigned to the TWT service interval TWT SP is changed.
  • the STA 1920 may transmit an uplink frame (eg, a data frame UL DATA) in a second TWT service period (TWT SP2), which is not limited to a frame transmitted by the STA.
  • an uplink frame eg, a data frame UL DATA
  • TWT SP2 TWT service period
  • 20 is a diagram illustrating power management of a WLAN system using a plurality of trigger frames in a TWT service interval according to an embodiment of the present disclosure.
  • the TWT flow identifier TWT FID included in the first beacon frame BF1 in the second section T1 to T2 of FIG. 20 may be set to '0'.
  • TWT SP TWT service interval
  • TWT FID TWT flow identifier
  • the STA 2020 operating in the power save (PS) mode transitions from the awake state to the sleep state after receiving the beacon frame. Subsequently, the STA 2020 may operate in an awake state in the TWT service interval (TWT SP) based on the TWT parameter set included in the first beacon frame.
  • TWT SP TWT service interval
  • the AP 2010 may transmit a plurality of trigger frames TF1 and TF2.
  • the trigger frame illustrated in FIG. 20 may be a trigger frame of a basic trigger method or a trigger frame of a method for a random access procedure.
  • a cascade indicator may be included in each of the plurality of trigger frames TF1 and TF2 according to one embodiment of the present specification of FIG. 20. For example, when the cascade indicator is '1', it indicates that a subsequent trigger frame exists. If the cascade indicator is '0', it indicates that there is no subsequent trigger frame.
  • first and second trigger frames TF1 and TF2 are continuously transmitted in a fourth section T3 to T4 and TWT SP.
  • the STA 2020 that receives the first trigger frame TF1 having the cascade indicator '1' may determine that a subsequent trigger frame is transmitted.
  • the STA 2020 that receives the second trigger frame TF2 having the cascade indicator '1' may determine that a subsequent trigger frame is transmitted. That is, the STA 2020 according to the embodiment of FIG. 20 may maintain an awake state even after the TWT service interval (TWT SP) for the subsequent trigger frame.
  • TWT SP TWT service interval
  • the AP of FIG. 20 may additionally allocate 1 bit in the trigger frame to distinguish the types of the plurality of trigger frames transmitted in the TWT service interval (TWT SP). That is, the AP may indicate to the STAs whether the subsequent trigger frame is a trigger frame in the same manner as the currently transmitted trigger frame or another trigger frame.
  • TWT SP TWT service interval
  • 21 is a flowchart illustrating power management of a WLAN system according to an embodiment of the present disclosure.
  • the STA may receive a beacon frame from the AP.
  • the beacon frame may include a TWT parameter set for a TWT service interval (TWT SP).
  • the beacon frame may include a TWT flow identifier (TWT FID) indicating an allowable group of the recommended frame transmitted by the STA in the TWT service interval (TWT SP).
  • TWT FID TWT flow identifier
  • the STA that receives the beacon frame may operate based on a plurality of element information included in the beacon frame.
  • the STA of the present specification may operate based on a TWT element of a beacon frame.
  • the STA operating in the power save (PS) mode may maintain the sleep state until the TWT service interval (TWT SP) after receiving the beacon frame. Subsequently, the STA may switch from the sleep state to the awake state at the start of the TWT service interval (TWT SP) based on the TWT parameter set. The STA may maintain an awake state during the TWT service interval (TWT SP).
  • TWT SP TWT service interval
  • the STA may determine whether the uplink frame for the AP is a recommended frame of the grant group indicated by the TWT flow identifier.
  • step S2130 if the STA determines that the uplink frame is not a recommended frame, the STA does not transmit the uplink frame in the TWT service interval (TWT SP).
  • TWT SP TWT service interval
  • step S2140 If the STA determines the uplink frame as the recommended frame, the STA may transmit the uplink frame to the AP.
  • 22 is a block diagram illustrating a wireless terminal to which an embodiment of the present specification can be applied.
  • a wireless terminal may be an STA that may implement 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 2200 includes a processor 2210, a memory 2220, and an RF unit 2230.
  • the RF unit 2230 may be connected to the processor 2210 to transmit / receive a radio signal.
  • the processor 2210 may implement the functions, processes, and / or methods proposed herein.
  • the processor 2110 may perform an operation according to the present embodiment described above.
  • the processor 2210 may perform an operation of the AP disclosed in the present embodiment of FIGS. 1 to 20.
  • the non-AP STA 2250 includes a processor 2260, a memory 2270, and an RF unit 2280.
  • the RF unit 2280 may be connected to the processor 2260 to transmit / receive a radio signal.
  • the processor 2260 may implement the functions, processes, and / or methods proposed in the present embodiment.
  • the processor 2260 may be implemented to perform the non-AP STA operation according to the present embodiment described above.
  • the processor 2260 may perform an operation of the non-AP STA disclosed in the present embodiment of FIGS. 1 to 21.
  • Processors 2210 and 2260 may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, data processing devices, and / or converters to convert baseband signals and wireless signals to and from each other.
  • the memories 2120 and 2170 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices.
  • the RF unit 2230 and 2280 may include one or more antennas for transmitting and / or receiving a radio signal.
  • the above-described technique may be implemented as a module (process, function, etc.) for performing the above-described function.
  • the module may be stored in the memories 2220 and 2270 and executed by the processors 2210 and 2260.
  • the memories 2220 and 2270 may be inside or outside the processors 2210 and 2260, and may be connected to the processors 2210 and 2260 by various well-known means.

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

Abstract

Conformément à un mode de réalisation, la présente invention concerne un procédé qui consiste : à recevoir, par une station (STA) à partir d'un point d'accès (AP), une première trame de balise comprenant un ensemble de paramètres TWT pour un intervalle de service TWT et un identificateur de flux TWT indiquant un groupe d'autorisation d'une trame de conseil transmise par la STA dans un intervalle de service TWT ; à passer, par la STA, d'un état activé à un état désactivé après la réception d'une première trame de balise ; à passer, par la STA, de l'état désactivé à l'état activé sur la base d'un ensemble de paramètres TWT ; à déterminer, par la STA, si une première trame de liaison montante (UL) pour un AP est ou non une trame de recommandation sur la base d'un identificateur de flux TWT ; et à déterminer, par la STA, si la première trame UL est ou non transmise dans l'intervalle de service TWT selon le résultat de détermination.
PCT/KR2017/000189 2016-01-07 2017-01-06 Procédé pour une gestion de puissance et terminal utilisant ledit procédé dans un système lan sans fil WO2017119759A1 (fr)

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CN117098183A (zh) * 2020-12-31 2023-11-21 华为技术有限公司 一种通信方法、装置及计算机可读存储介质
CN117098182A (zh) * 2020-12-31 2023-11-21 华为技术有限公司 一种通信方法、装置及计算机可读存储介质
WO2022158801A1 (fr) * 2021-01-19 2022-07-28 엘지전자 주식회사 Procédé et dispositif de signalisation d'ersp dans un système lan sans fil
CN113938999A (zh) * 2021-10-29 2022-01-14 中国电子科技集团公司第五十四研究所 通信方法、系统、TWT用户节点和WiFi接入点

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