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WO2018164380A1 - Procédé d'émission ou de réception de trame de radio de réveil dans un système de réseau local sans fil et appareil associé - Google Patents

Procédé d'émission ou de réception de trame de radio de réveil dans un système de réseau local sans fil et appareil associé Download PDF

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Publication number
WO2018164380A1
WO2018164380A1 PCT/KR2018/001651 KR2018001651W WO2018164380A1 WO 2018164380 A1 WO2018164380 A1 WO 2018164380A1 KR 2018001651 W KR2018001651 W KR 2018001651W WO 2018164380 A1 WO2018164380 A1 WO 2018164380A1
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Prior art keywords
wur
ppdu
sta
sequence
bit
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PCT/KR2018/001651
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English (en)
Korean (ko)
Inventor
임동국
류기선
박은성
최진수
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엘지전자 주식회사
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Publication of WO2018164380A1 publication Critical patent/WO2018164380A1/fr

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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. Transmission Power Control [TPC] or power classes
    • H04W52/02Power saving arrangements
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W56/00Synchronisation arrangements
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02DCLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00Reducing energy consumption in communication networks
    • Y02D30/70Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • the present invention relates to a wireless LAN system, and more particularly, to a method and apparatus for transmitting or receiving a WUR frame through a wake up radio (WUR) to wake up a primary connectivity radio (PCR).
  • WUR wake up radio
  • PCR primary connectivity radio
  • IEEE 802.11a and b are described in 2.4. Using unlicensed band at GHz or 5 GHz, IEEE 802.11b provides a transmission rate of 11 Mbps and IEEE 802.11a provides a transmission rate of 54 Mbps.
  • IEEE 802.11g applies orthogonal frequency-division multiplexing (OFDM) at 2.4 GHz to provide a transmission rate of 54 Mbps.
  • IEEE 802.11n applies multiple input multiple output OFDM (MIMO-OFDM) to provide a transmission rate of 300 Mbps for four spatial streams. IEEE 802.11n supports channel bandwidths up to 40 MHz, in this case providing a transmission rate of 600 Mbps.
  • the WLAN standard uses a maximum of 160MHz bandwidth, supports eight spatial streams, and supports IEEE 802.11ax standard through an IEEE 802.11ac standard supporting a speed of up to 1Gbit / s.
  • An object of the present invention is to provide a method and apparatus for transmitting or receiving a WUR frame more accurately and efficiently.
  • the present invention is not limited to the above-described technical problem and other technical problems can be inferred from the embodiments of the present invention.
  • an access point (AP) for transmitting a wake up radio (WUR) physical layer protocol data unit (PPDU) includes a sequence for time synchronization and a WUR SIG (signal)
  • a processor for generating a WUR preamble including the field and a transmitter for transmitting a WUR PPDU including the generated WUR preamble and a WUR frame body under control of the processor, wherein the sequence for time synchronization comprises at least two times a minimum repetitive sequence of N-bit length.
  • N is an integer greater than or equal to 2
  • the first N-bits of the WUR SIG field located after the sequence for time synchronization are bit values corresponding to the minimum repeating sequence among a plurality of bit values that can be represented as N-bits. It can be set to one of the remaining bit values except.
  • a method of receiving a wake up radio (WUR) physical layer protocol data unit (PPDU) in a WLAN system includes a WUR preamble and a WUR frame body.
  • N is an integer greater than or equal to 2
  • the first N-bit of the WUR SIG field may be set to one of the remaining bit values except for the bit value corresponding to the minimum repetition sequence among a plurality of bit values that can be represented as N-bits.
  • the first N-bits of the WUR SIG field may include mode indication information indicating a mode used for transmission of the WUR PPDU among a broadcast mode, a multicast mode, and a unicast mode.
  • the length of the WUR PPDU may be determined according to the PPDU type specific to the mode indicated by the mode indication information.
  • the WUR SIG field may further include information about a data rate applied to the WUR frame body.
  • the information on the data rate indicates a high or low, and the actual value of the data rate corresponding to the high or low may be signaled through a primary connectivity radio (PCR).
  • PCR primary connectivity radio
  • the WUR SIG field may further include information indicating whether transmission of the WUR PPDU is performed on a single channel or on multiple channels.
  • the WUR SIG field may further include at least one of information on a basic service set (BSS) identifier, information indicating whether to apply Manchester coding, and cyclic redundancy check (CRC) information.
  • BSS basic service set
  • CRC cyclic redundancy check
  • the information on the WUR PPDU is indicated early through the WUR SIG field of the WUR preamble, so that the third party WUR STA can minimize unnecessary power consumption after receiving the corresponding WUR PPDU. Since the WUR SIG field starts with a bit value different from the minimum repetition sequence of the time synchronization sequence, the time synchronization sequence and the WUR SIG field can be clearly distinguished.
  • FIG. 1 is a diagram illustrating an example of a configuration of a WLAN system.
  • FIG. 2 is a diagram illustrating another example of a configuration of a WLAN system.
  • FIG. 3 is a diagram illustrating a general link setup process.
  • FIG. 4 is a diagram for describing a backoff process.
  • 5 is a diagram for explaining hidden nodes and exposed nodes.
  • FIG. 6 is a diagram for explaining an RTS and a CTS.
  • 7 to 9 are diagrams for explaining the operation of the STA receiving the TIM.
  • FIG. 10 is a diagram for explaining an example of a frame structure used in an IEEE 802.11 system.
  • FIG. 11 is a diagram illustrating a WUR receiver usable in a WLAN system (e.g., 802.11).
  • FIG. 13 shows an example of a WUR packet.
  • FIG. 14 illustrates a waveform for a WUR packet.
  • FIG. 15 illustrates a WUR packet generated using an OFDM transmitter of a wireless LAN.
  • 16 illustrates the structure of a WUR receiver.
  • FIG. 17 shows an example of a frame structure of a WUR PPDU.
  • FIG. 19 illustrates a flow of a WUR PPDU transmission / reception method according to an embodiment of the present invention.
  • 20 is a view for explaining an apparatus according to an embodiment of the present invention.
  • the following description relates to a method and an apparatus therefor for efficiently utilizing a channel having a wide band in a WLAN system.
  • a WLAN system to which the present invention is applied will be described in detail.
  • FIG. 1 is a diagram illustrating an example of a configuration of a WLAN system.
  • the WLAN system includes one or more basic service sets (BSSs).
  • BSS is a set of stations (STAs) that can successfully synchronize and communicate with each other.
  • An STA is a logical entity that includes a medium access control (MAC) and a physical layer interface to a wireless medium.
  • the STA is an access point (AP) and a non-AP STA (Non-AP Station). Include.
  • the portable terminal operated by the user among the STAs is a non-AP STA, and when referred to simply as an STA, it may also refer to a non-AP STA.
  • a non-AP STA is a terminal, a wireless transmit / receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile terminal, or a mobile subscriber. It may also be called another name such as a mobile subscriber unit.
  • the AP is an entity that provides an associated station (STA) coupled to the AP to access a distribution system (DS) through a wireless medium.
  • STA station
  • DS distribution system
  • the AP may be called a centralized controller, a base station (BS), a Node-B, a base transceiver system (BTS), or a site controller.
  • BS base station
  • BTS base transceiver system
  • BSS can be divided into infrastructure BSS and Independent BSS (IBSS).
  • IBSS Independent BSS
  • the BBS shown in FIG. 1 is an IBSS.
  • the IBSS means a BSS that does not include an AP. Since the IBSS does not include an AP, access to the DS is not allowed, thereby forming a self-contained network.
  • FIG. 2 is a diagram illustrating another example of a configuration of a WLAN system.
  • the BSS shown in FIG. 2 is an infrastructure BSS.
  • Infrastructure BSS includes one or more STAs and APs.
  • communication between non-AP STAs is performed via an AP.
  • AP access point
  • a plurality of infrastructure BSSs may be interconnected through a DS.
  • a plurality of BSSs connected through a DS is called an extended service set (ESS).
  • STAs included in the ESS may communicate with each other, and a non-AP STA may move from one BSS to another BSS while seamlessly communicating within the same ESS.
  • the DS is a mechanism for connecting a plurality of APs.
  • the DS is not necessarily a network, and there is no limitation on the form if it can provide a predetermined distribution service.
  • the DS may be a wireless network such as a mesh network or a physical structure that connects APs to each other.
  • the operation of the STA operating in the WLAN system may be described in terms of a layer structure.
  • the hierarchy may be implemented by a processor.
  • the STA may have a plurality of hierarchical structures.
  • the hierarchical structure covered by the 802.11 standard document is mainly the MAC sublayer and physical (PHY) layer on the DLL (Data Link Layer).
  • the PHY may include a Physical Layer Convergence Procedure (PLCP) entity, a Physical Medium Dependent (PMD) entity, and the like.
  • PLCP Physical Layer Convergence Procedure
  • PMD Physical Medium Dependent
  • the MAC sublayer and PHY conceptually contain management entities called MAC sublayer management entities (MLMEs) and physical layer management entities (PLMEs), respectively.These entities provide a layer management service interface on which layer management functions operate. .
  • SME Station Management Entity
  • An SME is a layer-independent entity that can appear to be in a separate management plane or appear to be off to the side. While the exact features of the SME are not described in detail in this document, they generally do not include the ability to collect layer-dependent states from various Layer Management Entities (LMEs), and to set similar values for layer-specific parameters. You may seem to be in charge. SMEs can generally perform these functions on behalf of general system management entities and implement standard management protocols.
  • LMEs Layer Management Entities
  • the aforementioned entities interact in a variety of ways.
  • entities can interact by exchanging GET / SET primitives.
  • a primitive means a set of elements or parameters related to a particular purpose.
  • the XX-GET.request primitive is used to request the value of a given MIB attribute (management information based attribute information).
  • the XX-GET.confirm primitive is used to return the appropriate MIB attribute information value if the Status is "Success", otherwise it is used to return an error indication in the Status field.
  • the XX-SET.request primitive is used to request that the indicated MIB attribute be set to a given value. If the MIB attribute means a specific operation, this is to request that the operation be performed.
  • the XX-SET.confirm primitive confirms that the indicated MIB attribute is set to the requested value when status is "success", otherwise it is used to return an error condition in the status field. If the MIB attribute means a specific operation, this confirms that the operation has been performed.
  • the MLME and SME may exchange various MLME_GET / SET primitives through a MLME_SAP (Service Access Point).
  • various PLME_GET / SET primitives may be exchanged between PLME and SME through PLME_SAP and may be exchanged between MLME and PLME through MLME-PLME_SAP.
  • FIG. 3 is a diagram illustrating a general link setup process.
  • an STA In order for an STA to set up a link and transmit / receive data with respect to a network, an STA first discovers the network, performs authentication, establishes an association, and authenticates for security. It must go through the back.
  • the link setup process may also be referred to as session initiation process and session setup process.
  • a process of discovery, authentication, association, and security establishment of a link setup process may be collectively referred to as association process.
  • the STA may perform a network discovery operation.
  • the network discovery operation may include a scanning operation of the STA. That is, in order for the STA to access the network, the STA must find a network that can participate. The STA must identify a compatible network before joining the wireless network. A network identification process existing in a specific area is called scanning.
  • the STA performing scanning transmits a probe request frame and waits for a response to discover which AP exists in the vicinity while moving channels.
  • the responder transmits a probe response frame to the STA that transmits the probe request frame in response to the probe request frame.
  • the responder may be an STA that last transmitted a beacon frame in the BSS of the channel being scanned.
  • the AP transmits a beacon frame, so the AP becomes a responder.
  • the responder is not constant.
  • an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 stores the BSS-related information included in the received probe response frame and stores the next channel (eg, number 2).
  • Channel to perform scanning (i.e., probe request / response transmission and reception on channel 2) in the same manner.
  • the scanning operation may be performed by a passive scanning method.
  • passive scanning the STA performing scanning waits for a beacon frame while moving channels.
  • the beacon frame is one of management frames in IEEE 802.11.
  • the beacon frame is notified of the existence of a wireless network and is periodically transmitted to allow the STA performing scanning to find the wireless network and participate in the wireless network.
  • the AP periodically transmits a beacon frame
  • the IBSS STAs in the IBSS rotate and transmit a beacon frame.
  • the STA that performs the scanning receives the beacon frame, the STA stores the information on the BSS included in the beacon frame and records beacon frame information in each channel while moving to another channel.
  • the STA may store BSS related information included in the received beacon frame, move to the next channel, and perform scanning on the next channel in the same manner.
  • active scanning has the advantage of less delay and power consumption than passive scanning.
  • step S520 After the STA discovers the network, an authentication process may be performed in step S520.
  • This authentication process may be referred to as a first authentication process in order to clearly distinguish from the security setup operation of step S540 described later.
  • the authentication process includes a process in which the STA transmits an authentication request frame to the AP, and in response thereto, the AP transmits an authentication response frame to the STA.
  • An authentication frame used for authentication request / response corresponds to a management frame.
  • the authentication frame includes an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network, and a finite cyclic group. Group) and the like. This corresponds to some examples of information that may be included in the authentication request / response frame, and may be replaced with other information or further include additional information.
  • the STA may send an authentication request frame to the AP.
  • the AP may determine whether to allow authentication for the corresponding STA based on the information included in the received authentication request frame.
  • the AP may provide a result of the authentication process to the STA through an authentication response frame.
  • the association process includes a process in which the STA transmits an association request frame to the AP, and in response thereto, the AP transmits an association response frame to the STA.
  • the association request frame may include information related to various capabilities, beacon listening interval, service set identifier (SSID), supported rates, supported channels, RSN, mobility domain. Information about supported operating classes, TIM Broadcast Indication Map Broadcast request, interworking service capability, and the like.
  • an association response frame may include information related to various capabilities, status codes, association IDs (AIDs), support rates, Enhanced Distributed Channel Access (EDCA) parameter sets, Received Channel Power Indicators (RCPI), Received Signal to Noise Information, such as an indicator, a mobility domain, a timeout interval (association comeback time), an overlapping BSS scan parameter, a TIM broadcast response, and a QoS map.
  • AIDs association IDs
  • EDCA Enhanced Distributed Channel Access
  • RCPI Received Channel Power Indicators
  • Received Signal to Noise Information such as an indicator, a mobility domain, a timeout interval (association comeback time), an overlapping BSS scan parameter, a TIM broadcast response, and a QoS map.
  • a security setup process may be performed at step S540.
  • the security setup process of step S540 may be referred to as an authentication process through a Robust Security Network Association (RSNA) request / response.
  • the authentication process of step S520 is called a first authentication process, and the security setup process of step S540 is performed. It may also be referred to simply as the authentication process.
  • RSNA Robust Security Network Association
  • the security setup process of step S540 may include, for example, performing a private key setup through 4-way handshaking through an Extensible Authentication Protocol over LAN (EAPOL) frame. .
  • the security setup process may be performed according to a security scheme not defined in the IEEE 802.11 standard.
  • a basic access mechanism of MAC is a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism.
  • the CSMA / CA mechanism is also called the Distributed Coordination Function (DCF) of the IEEE 802.11 MAC. It basically employs a "listen before talk" access mechanism.
  • the AP and / or STA may sense a radio channel or medium during a predetermined time period (e.g., during a DCF Inter-Frame Space (DIFS), before starting transmission.
  • DIFS DCF Inter-Frame Space
  • a delay period for example, a random backoff period
  • HCF hybrid coordination function
  • the PCF refers to a polling-based synchronous access scheme in which polling is performed periodically so that all receiving APs and / or STAs can receive data frames.
  • the HCF has an Enhanced Distributed Channel Access (EDCA) and an HCF Controlled Channel Access (HCCA).
  • EDCA is a competition based approach for providers to provide data frames to multiple users, and HCCA uses a non-competition based channel access scheme using a polling mechanism.
  • the HCF includes a media access mechanism for improving the quality of service (QoS) of the WLAN, and can transmit QoS data in both a contention period (CP) and a contention free period (CFP).
  • QoS quality of service
  • FIG. 4 is a diagram for describing a backoff process.
  • the random backoff count has a packet number value and may be determined as one of values ranging from 0 to CW.
  • CW is a contention window parameter value.
  • the CW parameter is given CWmin as an initial value, but may take a double value in case of transmission failure (eg, when an ACK for a transmitted frame is not received).
  • the STA continues to monitor the medium while counting down the backoff slots according to the determined backoff count value. If the medium is monitored as occupied, the countdown stops and waits; if the medium is idle, it resumes the remaining countdown.
  • the STA3 may confirm that the medium is idle as much as DIFS and transmit the frame immediately. Meanwhile, the remaining STAs monitor and wait for the medium to be busy. In the meantime, data may also be transmitted in each of STA1, STA2, and STA5, and each STA waits for DIFS when the medium is monitored idle, and then counts down the backoff slot according to a random backoff count value selected by the STA. Can be performed. In the example of FIG. 4, STA2 selects the smallest backoff count value, and STA1 selects the largest backoff count value.
  • the remaining backoff time of the STA5 is shorter than the remaining backoff time of the STA1 at the time when the STA2 finishes the backoff count and starts the frame transmission.
  • STA1 and STA5 stop counting for a while and wait for STA2 to occupy the medium.
  • the STA1 and the STA5 resume the stopped backoff count after waiting for DIFS. That is, the frame transmission can be started after counting down the remaining backoff slots by the remaining backoff time. Since the remaining backoff time of the STA5 is shorter than that of the STA1, the STA5 starts frame transmission. Meanwhile, while STA2 occupies the medium, data to be transmitted may also occur in STA4.
  • the STA4 waits for DIFS, performs a countdown according to a random backoff count value selected by the STA4, and starts frame transmission.
  • the remaining backoff time of STA5 coincides with an arbitrary backoff count value of STA4.
  • a collision may occur between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 receive an ACK, and thus data transmission fails. In this case, STA4 and STA5 may double the CW value, select a random backoff count value, and perform a countdown.
  • the STA1 waits while the medium is occupied due to transmission of the STA4 and STA5, waits for DIFS when the medium is idle, and starts frame transmission after the remaining backoff time passes.
  • the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing in which the AP and / or STA directly sense the medium.
  • Virtual carrier sensing is intended to compensate for problems that may occur in media access, such as a hidden node problem.
  • the MAC of the WLAN system may use a network allocation vector (NAV).
  • the NAV is a value in which an AP and / or STA currently using or authorized to use a medium instructs another AP and / or STA how long to remain until the medium becomes available.
  • the value set to NAV corresponds to a period in which the medium is scheduled to be used by the AP and / or STA transmitting the corresponding frame, and the STA receiving the NAV value is prohibited from accessing the medium during the period.
  • the NAV may be set, for example, according to the value of the "duration" field of the MAC header of the frame.
  • 5 is a diagram for explaining hidden nodes and exposed nodes.
  • 5A illustrates an example of a hidden node, in which STA A and STA B are in communication and STA C has information to transmit.
  • STA A may be transmitting information to STA B, it may be determined that the medium is idle when STA C performs carrier sensing before sending data to STA B. This is because transmission of STA A (ie, media occupation) may not be sensed at the location of STA C.
  • STA B since STA B receives the information of STA A and STA C at the same time, a collision occurs.
  • STA A may be referred to as a hidden node of STA C.
  • FIG. 5B is an example of an exposed node
  • STA B is a case in which STA C has information to be transmitted from STA D while transmitting data to STA A.
  • FIG. 5B is an example of an exposed node
  • STA C is a case in which STA C has information to be transmitted from STA D while transmitting data to STA A.
  • FIG. 5B when STA C performs carrier sensing, it may be determined that the medium is occupied by the transmission of STA B. Accordingly, since STA C is sensed as a medium occupancy state even if there is information to be transmitted to STA D, it must wait until the medium becomes idle. However, since STA A is actually outside the transmission range of STA C, transmission from STA C and transmission from STA B may not collide with STA A's point of view, so STA C is unnecessary until STA B stops transmitting. To wait. At this time, STA C may be referred to as an exposed node of STA B.
  • FIG. 6 is a diagram for explaining an RTS and a CTS.
  • a short signaling packet such as a request to send (RTS) and a clear to send (CTS) may be used.
  • RTS request to send
  • CTS clear to send
  • the RTS / CTS between the two STAs may allow the surrounding STA (s) to overhear, allowing the surrounding STA (s) to consider whether to transmit information between the two STAs. For example, when an STA to transmit data transmits an RTS frame to an STA receiving the data, the STA receiving the data may inform the neighboring STAs that they will receive the data by transmitting the CTS frame.
  • FIG. 6A illustrates an example of a method for solving a hidden node problem, and assumes that both STA A and STA C try to transmit data to STA B.
  • FIG. 6A When STA A sends the RTS to STA B, STA B transmits the CTS to both STA A and STA C around it. As a result, STA C waits until data transmission between STA A and STA B is completed, thereby avoiding collision.
  • FIG. 6 (b) illustrates an example of a method for solving an exposed node problem
  • STA C overhears RTS / CTS transmission between STA A and STA B so that STA C may use another STA (eg, STA). It may be determined that no collision will occur even if data is transmitted to D). That is, STA B transmits the RTS to all neighboring STAs, and only STA A having the data to actually transmit the CTS. Since STA C receives only RTS and not STA A's CTS, it can be seen that STA A is out of STC C's carrier sensing.
  • the WLAN system channel sensing must be performed before the STA performs transmission and reception, and always sensing the channel causes continuous power consumption of the STA.
  • the power consumption in the receive state is not significantly different from the power consumption in the transmit state, and maintaining the receive state is also a great burden for the power limited STA (ie, operated by a battery). Therefore, if the STA maintains the reception standby state in order to continuously sense the channel, it inefficiently consumes power without any particular advantage in terms of WLAN throughput.
  • the WLAN system supports a power management (PM) mode of the STA.
  • PM power management
  • the power management mode of the STA is divided into an active mode and a power save (PS) mode.
  • the STA basically operates in the active mode.
  • the STA operating in the active mode maintains an awake state.
  • the awake state is a state in which normal operation such as frame transmission and reception or channel scanning is possible.
  • the STA operating in the PS mode operates by switching between a sleep state (or a doze state) and an awake state.
  • the STA operating in the sleep state operates at the minimum power, and does not perform frame scanning as well as channel scanning.
  • the STA operates in the sleep state for as long as possible, power consumption is reduced, so the STA has an increased operation period. However, it is impossible to operate unconditionally long because frame transmission and reception are impossible in the sleep state. If there is a frame to be transmitted to the AP, the STA operating in the sleep state may transmit the frame by switching to the awake state. On the other hand, when the AP has a frame to transmit to the STA, the STA in the sleep state may not receive it and may not know that there is a frame to receive. Accordingly, the STA may need to switch to the awake state according to a specific period in order to know whether or not the frame to be transmitted to (or, if there is, receive it) exists.
  • the AP may transmit a beacon frame to STAs in the BSS at regular intervals.
  • the beacon frame may include a traffic indication map (TIM) information element.
  • the TIM information element may include information indicating that the AP has buffered traffic for STAs associated with the AP and transmits a frame.
  • the TIM element includes a TIM used to inform unicast frames and a delivery traffic indication map (DTIM) used to inform multicast or broadcast frames.
  • DTIM delivery traffic indication map
  • 7 to 9 are diagrams for explaining in detail the operation of the STA receiving the TIM.
  • the STA may switch from the sleep state to the awake state to receive a beacon frame including the TIM from the AP, interpret the received TIM element, and know that there is buffered traffic to be transmitted to the AP. .
  • the STA may transmit a PS-Poll frame to request an AP to transmit a data frame.
  • the AP may transmit the frame to the STA.
  • the STA may receive a data frame and transmit an acknowledgment (ACK) frame thereto to the AP.
  • the STA may then go back to sleep.
  • ACK acknowledgment
  • the AP may operate according to an immediate response method of transmitting a data frame after a predetermined time (for example, a short inter-frame space (SIFS)) after receiving a PS-Poll frame from an STA. Can be. Meanwhile, when the AP fails to prepare a data frame to be transmitted to the STA during the SIFS time after receiving the PS-Poll frame, the AP may operate according to a deferred response method, which will be described with reference to FIG. 8.
  • a predetermined time for example, a short inter-frame space (SIFS)
  • SIFS short inter-frame space
  • the STA switches from the sleep state to the awake state to receive the TIM from the AP and transmits the PS-Poll frame to the AP through contention as in the example of FIG. 7. If the AP does not prepare a data frame during SIFS even after receiving the PS-Poll frame, the AP may transmit an ACK frame to the STA instead of transmitting the data frame. When the data frame is prepared after transmitting the ACK frame, the AP may transmit the data frame to the STA after performing contention. The STA may transmit an ACK frame indicating that the data frame was successfully received to the AP and go to sleep.
  • STAs may transition from a sleep state to an awake state to receive a beacon frame containing a DTIM element from the AP. STAs may know that a multicast / broadcast frame will be transmitted through the received DTIM.
  • the AP may transmit data (ie, multicast / broadcast frame) immediately after the beacon frame including the DTIM without transmitting and receiving the PS-Poll frame.
  • the STAs may receive data while continuously awake after receiving the beacon frame including the DTIM, and may switch back to the sleep state after the data reception is completed.
  • FIG. 10 is a diagram for explaining an example of a frame structure used in an IEEE 802.11 system.
  • the Physical Layer Protocol Data Unit (PPDU) frame format may include a Short Training Field (STF), a Long Training Field (LTF), a SIG (SIGNAL) field, and a Data field.
  • STF Short Training Field
  • LTF Long Training Field
  • SIGNAL SIGNAL
  • Data field a Data field.
  • the most basic (eg, non-HT) PPDU frame format may include only a legacy-STF (L-STF), a legacy-LTF (L-LTF), a SIG field, and a data field.
  • the STF is a signal for signal detection, automatic gain control (AGC), diversity selection, precise time synchronization, etc.
  • the LTF is a signal for channel estimation, frequency error estimation, and the like.
  • the STF and LTF may be referred to as a PLCP preamble, and the PLCP preamble may be referred to as a signal for synchronization and channel estimation of an OFDM physical layer.
  • the SIG field may include a RATE field and a LENGTH field.
  • the RATE field may include information about modulation and coding rate of data.
  • the LENGTH field may include information about the length of data.
  • the SIG field may include a parity bit, a SIG TAIL bit, and the like.
  • the data field may include a SERVICE field, a physical layer service data unit (PSDU), a PPDU TAIL bit, and may also include a padding bit if necessary.
  • Some bits of the SERVICE field may be used for synchronization of the descrambler at the receiving end.
  • the PSDU corresponds to an MPDU (MAC Protocol Data Unit) defined in the MAC layer and may include data generated / used in an upper layer.
  • the PPDU TAIL bit can be used to return the encoder to zero.
  • the padding bit may be used to adjust the length of the data field in a predetermined unit.
  • the MPDU is defined according to various MAC frame formats, and the basic MAC frame is composed of a MAC header, a frame body, and a frame check sequence (FCS).
  • the MAC frame may consist of MPDUs and may be transmitted / received through the PSDU of the data portion of the PPDU frame format.
  • the MAC header includes a frame control field, a duration / ID field, an address field, and the like.
  • the frame control field may include control information required for frame transmission / reception.
  • the duration / ID field may be set to a time for transmitting the corresponding frame.
  • the duration / ID field included in the MAC header may be set to 16 bits long (e.b., B0 to B15).
  • the content included in the period / ID field may vary depending on the frame type and subtype, whether the content is transmitted during the CFP (contention free period), the QoS capability of the transmitting STA, and the like.
  • the duration / ID field may include the AID of the transmitting STA (e.g., via 14 LSB bits), and 2 MSB bits may be set to one.
  • the period / ID field may be set to a fixed value (e.g., 32768).
  • the duration / ID field may include a duration value defined for each frame type.
  • Sequence Control, QoS Control, and HT Control subfields of the MAC header refer to the IEEE 802.11 standard document.
  • the frame control field of the MAC header may include Protocol Version, Type, Subtype, To DS, From DS, More Fragment, Retry, Power Management, More Data, Protected Frame, Order subfields.
  • the content of each subfield of the frame control field may refer to an IEEE 802.11 standard document.
  • an STA includes a primary connectivity radio (PCR) (eg, IEEE 802.11a / b / g / n / ac / ax WLAN) and a wake up radio for main wireless communication.
  • PCR primary connectivity radio
  • WUR eg, IEEE 802.11ba
  • PCR is used for data transmission and reception, and may be turned off when there is no data to transmit and receive. As such, when the PCR is turned off, the WURx of the STA may wake up the PCR when there is a packet to receive. Therefore, user data is transmitted and received through PCR.
  • WURx is not used for user data, it can only serve to wake up the PCR transceiver.
  • WURx can be in the form of a simple receiver without a transmitter and is active while PCR is off. It is desirable that the target power consumption of the WURx in the activated state does not exceed 100 microwatts (uW).
  • a simple modulation scheme for example, an on-off keying (OOK) scheme, may be used, and a narrow bandwidth (e.g., 4 MHz, 5 MHz) may be used.
  • the reception range (e.g., distance) that WURx targets may be equivalent to the current 802.11.
  • FIG. 12 is a diagram for explaining the design and operation of a WUR packet.
  • the WUR packet may include a PCR part 1200 and a WUR part 1205.
  • the PCR part 1200 is for coexistence with the legacy WLAN system, and the PCR part may be referred to as a WLAN preamble.
  • the PCR part may be referred to as a WLAN preamble.
  • at least one or more of L-STF, L-LTF, and L-SIG of the legacy WLAN may be included in the PCR part 1200.
  • the 3rd party legacy STA may know that the WUR packet is not intended for the user through the PCR part 1200 of the WUR packet, and that the medium of the PCR is occupied by another STA.
  • WURx does not decode the PCR part of the WUR packet. This is because WURx, which supports narrowband and OOK demodulation, does not support PCR signal reception.
  • At least a part of the WUR part 1205 may be modulated by an on-off keying (OOK) method.
  • the WUR part may include at least one of a WUR preamble, a MAC header (e.g., a recipient address, etc.), a frame body, and a frame check sequence (FCS).
  • OOK modulation may be performed by modifying the OFDM transmitter.
  • WURx 1210 consumes very little power of 100 uW or less as described above and can be implemented with a small and simple OOK demodulator.
  • the WUR packet since the WUR packet needs to be designed to be compatible with the WLAN system, the WUR packet includes a preamble (eg, OFDM) and a new LP-WUR signal waveform (eg, OOK) of legacy WLAN. can do.
  • a preamble eg, OFDM
  • a new LP-WUR signal waveform eg, OOK
  • the WUR packet of FIG. 13 shows an example of a WUR packet.
  • the WUR packet of FIG. 13 includes a PCR part (e.g., legacy WLAN preamble) for coexistence with a legacy STA.
  • a PCR part e.g., legacy WLAN preamble
  • the legacy WLAN preamble may include L-STF, L-LTF, and L-SIG.
  • the WLAN STA e.g., 3rd Party
  • the L-SIG field may indicate the length of the payload (e.g., OOK modulated) of the WUR packet.
  • the WUR part may include at least one of a WUR preamble, a MAC header, a frame body, and an FCS.
  • the WUR preamble may include, for example, a PN sequence.
  • the MAC header may include the receiver address.
  • the frame body may contain other information needed for wake up.
  • the FCS may include a cyclic redundancy check (CRC).
  • FIG. 14 illustrates the waveform for the WUR packet of FIG. 13.
  • 1 bit may be transmitted per 1 OFDM symbol length (e.g., 4 usec).
  • the data rate of the WUR part may be 250 kbps.
  • FIG. 15 illustrates generation of a WUR packet using an OFDM transmitter of a wireless LAN.
  • a phase shift keying (PSK) -OFDM transmission scheme is used.
  • Generating a WUR packet by adding a separate OOK modulator for OOK modulation has a disadvantage of increasing an implementation cost of a transmitter. Therefore, a method of generating a OOK modulated WUR packet by reusing an OFDM transmitter will be described.
  • bit value 1 is a symbol (ie, on) in which any power in a symbol is loaded or has a power above a threshold
  • bit value 0 is a symbol in which no power in the symbol is loaded or has a power below a threshold. modulated to (ie, off).
  • bit value 1 it is also possible to define bit value 1 as power off.
  • OOK modulation scheme As described above, in the OOK modulation scheme, a bit value 1/0 is indicated through on / off of power at a corresponding symbol position.
  • Such a simple OOK modulation / demodulation scheme has an advantage of reducing power consumption and cost for realizing the signal detection / demodulation of the receiver.
  • OOK modulation for turning on / off a signal may be performed by reusing an existing OFDM transmitter.
  • the left graph of FIG. 15 shows real parts and imaginary parts of normalized amplitude during one symbol period (eg, 4 usec) for OOK modulated bit value 1 by reusing the OFDM transmitter of the existing WLAN. (imaginary) shows the part. Since the OOK modulation result for the bit value 0 corresponds to power off, illustration is omitted.
  • the right graph of FIG. 15 shows normalized power spectral density (PSD) in the frequency domain for OOK modulated bit value 1 by reusing an OFDM transmitter of an existing WLAN.
  • PSD power spectral density
  • a center 4 MHz in that band may be used for the WUR.
  • the WUR operates with a 4 MHz bandwidth.
  • a frequency bandwidth of another size may be used.
  • the subcarrier spacing (e.g., subcarrier spacing) is 312.5 kHz, and the bandwidth of the OOK pulse corresponds to 13 subcarriers.
  • CP cyclic prefix
  • the WUR packet may be referred to as a WUR signal, a WUR frame, or a WUR PPDU.
  • the WUR packet may be a packet for broadcast / multicast (e.g., WUR beacon) or a packet for unicast (e.g., a packet for terminating and waking up the WUR mode of a specific WUR STA).
  • the WURx may include an RF / analog front-end, a digital baseband processor, and a simple packet parser. 16 is an exemplary configuration, and the WUR receiver of the present invention is not limited to FIG.
  • a WLAN STA having a WUR receiver will be referred to simply as a WUR STA.
  • the WUR STA may be referred to simply as STA.
  • Manchester coding may be used to generate OOK symbols.
  • one-bit information is indicated through two sub information (or two coded bits).
  • two lower information bits '10' i.e., On-Off
  • the 1-bit information '1' passes through Manchester coding
  • two lower information bits '01' i.e., Off-On
  • the on-off order of the lower information bits may be reversed according to an embodiment.
  • one OOK symbol is 3.2 us in the time domain and corresponds to K subcarriers in the frequency domain, but the present invention is not limited thereto.
  • the length of 1 OOK symbol is (i) 1.6 us for the first lower information bit '1' and (ii) It can be divided into 1.6 us for the second lower information bit '0'.
  • a signal corresponding to the first lower information bit '1' is obtained by mapping ⁇ to odd subcarriers among K subcarriers, and mapping 0 to even subcarriers and performing IFFT.
  • IFFT is performed by mapping ⁇ at two subcarrier intervals on the frequency domain
  • a periodic signal of 1.6 us appears twice in the time domain.
  • the first or second signal of the 1.6 us periodic signal repeated twice may be used as the signal corresponding to the first lower information bit '1'.
  • may be, for example, 1 / sqrt (ceil (K / 2)) as the power normalization factor.
  • consecutive K subcarriers used to generate a signal corresponding to the first lower information bit '1' of all 64 subcarriers are, for example, [33-floor (K / 2): 33 + ceil (K / 2) -1].
  • the signal corresponding to the second lower information bit '0' may be obtained by mapping 0 to K subcarriers and performing IFFT.
  • consecutive K subcarriers used to generate a signal corresponding to the second lower information bit '0' of the total 64 subcarriers are, for example, [33-floor (K / 2): 33 + ceil (K / 2) -1].
  • the OOK symbol for 1-bit information '1' may be obtained by disposing a signal corresponding to the lower information bit '1' after the signal corresponding to the lower information bit '0'.
  • one symbol length for WUR may be set smaller than 3.2 us.
  • one symbol may be set to information + CP of 1.6us, 0.8us or 0.4us.
  • a time domain signal can be obtained by mapping 0 to K subcarriers and performing IFFT, one of which can be used with a 0.8us length signal.
  • a time domain signal can be obtained by mapping 0 to K subcarriers and performing IFFT, and one 0.4us length signal can be used.
  • the proposed WUR signal is generated through OOK modulation to reduce the reception power consumption of the receiver, and is transmitted by using an OFDM transmitter only on some tones within an available band (e.g., 20 MHz).
  • the WUR PPDU composed of the OOK symbols is transmitted without including user data for the WUR STA and including only control information. Accordingly, the WUR receiver (e.g., WUR STA) may determine whether the WUR PPDU is its own by decoding all control information transmitted through the WUR PPDU or by interacting with the MAC layer. As such, since the WUR receiver detects all control information of the received WUR PPDU or performs interaction with the MAC layer, the WUR receiver may consume excessive power to determine whether the WUR PPDU is for the WUR PPDU.
  • WUR STA may determine whether the WUR PPDU is its own by decoding all control information transmitted through the WUR PPDU or by interacting with the MAC layer. As such, since the WUR receiver detects all control information of the received WUR PPDU or performs interaction with the MAC layer, the WUR receiver may consume excessive power to determine whether the WUR PPDU is for the WUR PPDU.
  • FIG. 17 shows an example of a frame structure of a WUR PPDU.
  • the WUR PPDU may include an L-part at the beginning.
  • the WUR PPDU may further include a preamble part and a control information part for timing synch, packet detection, and / or received signal measurement for the WUR PPDU.
  • the L-part transmission is just one example. In another embodiment of the present invention, the L-part may be omitted when transmitting the WUR PPDU.
  • control information for the WUR receiver is transmitted through the control information part, it is difficult for the WUR receiver to immediately determine whether the corresponding PPDU is transmitted to itself without detecting and decoding all the control information.
  • an embodiment of the present invention proposes a WUR PPDU structure as shown in FIG. 18 in order to enable early detection of a PPDU received by a WUR receiver.
  • the WUR PPDU includes an L-Part for coexistence with a PCR STA similarly to FIG. 17.
  • the WUR part may include a WUR preamble and a WUR-SIG and WUR-Body.
  • the WUR-Body includes control information, not data, in the corresponding WUR STA.
  • user data for the WUR STA is provided via PCR after the WUR STA returns to the PCR mode.
  • At least one OOK off symbol may be inserted between the WUR preamble and the SIG field to distinguish the WUR preamble and the SIG field.
  • the mentioned OOK off symbol may not be included.
  • the WUR SIG field may include at least one of the following information.
  • BSS identifier information may be included in the SIG field of the WUR PPDU so that the WUR PPDU received by the STA can be determined whether it is transmitted from the BSS to which the WUR STA belongs.
  • the BSS identifier information may be BSS color (e.g., 6 bits) or Partial BSS ID (e.g., 9 bits or 10 bits).
  • the BSS identifier information may be located at the front of the SIG field so that the WUR STA can quickly determine the BSS.
  • Symbol Type For example, the type of the OOK symbol may be indicated through 1 bit or 2 bits. For example, a symbol type such as a normal OOK symbol and a OOK symbol to which Manchester coding is applied may be indicated.
  • Mode indication For example, the transmission mode of the WUR PPDU transmitted through 2 bits may be indicated.
  • the transmission mode may be one of a broadcast mode, a multicast mode, and a unicast mode, but is not limited thereto.
  • the WUR STA may determine whether the received WUR PPDU is a SU PPDU or an MU PPDU through a mode indication.
  • a data rate of data transmitted using a OOK symbol may be indicated through data rate information of 1 bit or 2 bits.
  • the data rate information may be understood as information similar to the MCS information of the existing PCR.
  • WUR PPDUs are transmitted using high data rates (eg, 250 kbps) when reception conditions are good, and WUR PPDUs are transmitted using low data rates (eg, 62.5 kbps) for robust transmission when the reception environment is poor. May be indicated.
  • (v) WUR PPDU Length The length information of the WUR PPDU may be indicated.
  • the other WUR STA corresponding to the 3rd party may set the NAV by the corresponding length by using the WUR PPDU length information, thereby reducing the reception power consumption.
  • CRC The CRC may be used to check for an error on receiving SIG field information.
  • the CRC may correspond to 3 bits or 4 bits, but this is just an example and the present invention is not limited thereto. Since the information size of the SIG field is small, the CRC may be set to 1 bit or 2 bits.
  • the WUR SIG field is preferably transmitted more robustly than other parts / information.
  • the WUR SIG field may be repeatedly transmitted. In this case, repetition of the WUR SIG field may be performed in units of symbols or in units of all WUR SIG fields.
  • the WUR SIG field may be transmitted as a OOK symbol to which Manchester coding is applied instead of a normal OOK symbol.
  • the WUR preamble may be divided into a part for auto-gain control (AGC) / synchronization and a WUR SIG field.
  • AGC auto-gain control
  • the AGC / synchronous part may be configured by repeating the ON symbol and the Off symbol.
  • a part for AGC / synchronization may be configured in the form of cross repeating 1 and 0 (eg, 1 0 1 0 1 0...) and the WUR STA uses AGC and time through power measurements for this sequence. Perform synchronization.
  • the WUR SIG field may be set as follows to distinguish between the AGC / synchronization part and the WUR SIG part in the WUR preamble, or to indicate the end of the AGC / synchronization part / start of the WUR SIG field.
  • WUR SIG field Although various information that can be transmitted through the WUR SIG field have been described above, information included in the WUR SIG field may be combined as follows to minimize the overhead of the WUR SIG field.
  • Mode indication (or PPDU type indication):
  • the mode / PPDU type indication may be 2-bit.
  • the mode / PPDU type indication may indicate a transmission mode (e.g., broadcasting / multicasting / unicasting) of a WUR PPDU to be transmitted.
  • a transmission mode e.g., broadcasting / multicasting / unicasting
  • length information on the corresponding PPDU may be indicated through a mode indication.
  • the transmission mode and the length information for the PPDU may be indicated together through the mode / PPDU type indication.
  • Data rate information Information indicating a data rate for WUR PPDU transmission, which may be set to 1 or 2-bit. For example, when the data rate information is 1-bit, only low (e.g., 0) or high (e.g., 1) of the data rate may be indicated. The data rate corresponding to the actual low / high may be indicated through PCR or may be determined through negotiation when the WUR STA accesses the AP through PCR. The information of each bit may include not only the data rate but also information on encoding, symbol length, and the like.
  • CRC may be set to 1-bit for parity check in order to minimize overhead.
  • a 1-bit CRC is just one example.
  • a 2-bit or 3-bit CRC may be used to reduce false positives and error probabilities.
  • the start of the WUR SIG field may be set differently from the AGC / sync sequence to distinguish between the AGC / sync part and the WUR SIG field or to indicate the end of the AGC / sync.
  • the AGC / sync sequence is 1 0 1 0 1 0...
  • WUR SIG field may be started with bit information different from 0 1 which is the minimum repetitive sequence of the AGC / synchronous sequence. Therefore, the bit information corresponding to the start information of the WUR SIG field is composed of 0 0, 0 1, 11 and 1 0 is not used.
  • the WUR SIG field starts with a 2-bit mode indication, use only three of the possible 2-bit configurations (eg, 00, 01, 10, 11) (eg, 00, 01, 11). Information can be transmitted.
  • the AGC / sync sequence is 0 1 0 1.
  • the WUR SIG field may start with bit information (e.g., 00, 10, 11) except for 0 1.
  • Data rate information Information indicating a data rate for WUR PPDU transmission, which may be set to 1 or 2-bit. For example, when the data rate information is 1-bit, only low (e.g., 0) or high (e.g., 1) of the data rate may be indicated. The data rate corresponding to the actual low / high may be indicated through PCR before the WUR STA enters the WUR mode or may be determined through negotiation when the WUR STA accesses the AP through PCR. When the data rate information is 1-bit, a dummy bit for distinguishing the AGC / sync can be added to the WUR SIG field. The information of each bit may include not only the data rate but also information on encoding, symbol length, and the like.
  • CRC The CRC may be set to 1-bit for parity check in order to minimize overhead.
  • a 1-bit CRC is just one example.
  • a 2-bit or 3-bit CRC may be used to reduce false positives and error probabilities.
  • the start information of the WUR SIG field may be set differently from the minimum repetition sequence of the AGC / synchronization sequence, whereby the distinction to the AGC / synchronization sequence and the end of the AGC / synchronization sequence may be indicated. have.
  • the ON / OFF symbol cannot be set via Manchester coding. Therefore, when multiple channels are used, information indicating that a symbol is set using a normal OOK rather than Manchester coding may be included in the WUR SIG field.
  • the SU / MU instruction may be 1 or 2-bit.
  • the SU / MU indication may indicate whether the WUR PPDU is transmitted through a single channel or multiple channels.
  • an ON / Off symbol may be set using Manchester coding.
  • an ON / OFF symbol may be set using a normal OOK.
  • Data rate information Information indicating a data rate for WUR PPDU transmission, which may be set to 1 or 2-bit. For example, when the data rate information is 1-bit, only low (e.g., 0) or high (e.g., 1) of the data rate may be indicated. The data rate corresponding to the actual low / high may be indicated through PCR or may be determined through negotiation when the WUR STA accesses the AP through PCR. The information of each bit may include not only the data rate but also information on encoding, symbol length, and the like.
  • CRC may be set to 1-bit for parity check in order to minimize overhead.
  • a 1-bit CRC is just one example.
  • a 2-bit or 3-bit CRC may be used to reduce false positives and error probabilities.
  • the start information of the WUR SIG field may be set differently from the minimum repetition sequence of the AGC / synchronization sequence, whereby the distinction to the AGC / synchronization sequence and the end of the AGC / synchronization sequence may be indicated. have.
  • a WUR STA cannot transmit a WUR PPDU in IEEE 802.11ba. Therefore, since the WUR STA cannot directly transmit feedback information on the received WUR PPDU using the WUR, a change in data rate for the WUR PPDU may not occur frequently. Therefore, as another example of the present invention, data rate information for a WUR PPDU may be transmitted through a WUR beacon, rather than being transmitted using a WUR SIG field. Accordingly, the WUR STA may determine whether the data rate is changed at every beacon period, and the AP does not need to transmit data rate information in the WUR SIG field of the WUR preamble every WUR PPDU transmission. therefore. The overhead of the preamble can be reduced. However, when information on the data rate is transmitted through the WUR beacon, the AP may not immediately change the data rate according to channel conditions.
  • an access point generates a WUR preamble including a sequence for time synchronization and a WUR SIG (signal) field (1905).
  • a sequence for time synchronization is generated by repeating at least two times a minimum repetitive sequence of N-bit length, and N may be an integer of 2 or more.
  • the first N-bits of the WUR SIG field located after the sequence for time synchronization may be set to one of the remaining bit values except the bit value corresponding to the minimum repetitive sequence among the plurality of bit values that can be represented as N-bits.
  • the WUR SIG field may further include information about a data rate applied to the WUR frame body.
  • the information about the data rate indicates high or low, and the actual value of the data rate corresponding to the high or the low may be signaled through a primary connectivity radio (PCR).
  • PCR primary connectivity radio
  • the WUR SIG field may further include information indicating whether transmission of the WUR PPDU is performed on a single channel or on multiple channels.
  • the WUR SIG field may further include at least one of information on a basic service set (BSS) identifier, information indicating whether to apply Manchester coding, and cyclic redundancy check (CRC) information.
  • BSS basic service set
  • CRC cyclic redundancy check
  • the AP transmits a WUR PPDU including the generated WUR preamble and the WUR frame body (1910).
  • the WUR STA performs synchronization on the WUR PPDU based on a sequence for time synchronization included in the WUR preamble (1915).
  • the WUR STA decodes a WUR SIG (signal) field located after the sequence for time synchronization in a WUR preamble (1920).
  • the WUR STA may early detect information on the WUR PPDU described above by decoding the WUR SIG field. For example, when the BSS identifier information does not match its BSS, the WUR STA may stop decoding the remaining WUR PPDU. In addition, if there is a CRC error, the WUR STA may stop decoding the remaining WUR PPDU.
  • the WUR STA decodes the information WUR frame body obtained by decoding the WUR SIG field (1925).
  • Information obtained by decoding the WUR SIG field may include, for example, transmission mode information, data rate information, and / or whether Manchester coding is applied, and the like.
  • the WUR STA may determine whether to wake up (i.e., exit the WUR mode and return to the PCR mode) according to the result of decoding the WUR frame body. When the WUR STA wakes up, it may receive a PCR PPDU from the AP through PCR.
  • 20 is a view for explaining an apparatus for implementing the method as described above.
  • the wireless device 100 of FIG. 20 may correspond to a specific STA of the above description, and the wireless device 850 may correspond to the AP of the above-described description.
  • the STA 100 may include a processor 110, a memory 120, and a transceiver 130, and the AP 150 may include a processor 160, a memory 170, and a transceiver 180.
  • the transceivers 130 and 180 transmit / receive wireless signals and may be implemented in a physical layer, such as IEEE 802.11 / 3GPP.
  • Processors 110 and 160 run at the physical layer and / or MAC layer and are coupled to transceivers 130 and 180.
  • Processors 110 and 160 may perform the aforementioned UL MU scheduling procedure.
  • Processors 110 and 160 and / or transceivers 130 and 180 may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and / or data processors.
  • the memories 120 and 170 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media and / or other storage units.
  • ROM read-only memory
  • RAM random access memory
  • flash memory memory cards
  • storage media storage media and / or other storage units.
  • the method described above can be executed as a module (eg, process, function) that performs the functions described above.
  • the module may be stored in the memories 120 and 170 and may be executed by the processors 110 and 160.
  • the memories 120 and 170 may be disposed inside or outside the processes 110 and 160, and may be connected to the processes 110 and 160 by well-known means.
  • the transceiver 130 of the STA may include a transmitter (not shown) and a receiver (not shown).
  • the receiver of the STA may include a main connected radio receiver for receiving a main connected radio signal (eg, a wireless LAN such as IEEE 802.11 a / b / g / n / ac / ax) and a WUR receiver for receiving a WUR signal.
  • the transmitter of the STA may include a primary connected radio transmitter for transmitting the primary connected radio signal.
  • the transceiver 180 of the AP may include a transmitter (not shown) and a receiver (not shown).
  • the transmitter of the AP may correspond to an OFDM transmitter.
  • the AP may transmit the WUR payload by the OOK scheme by reusing the OFDM transmitter. For example, as described above, the AP may OOK modulate the WUR payload through an OFDM transmitter.
  • the present invention can be applied to various wireless communication systems including IEEE 802.11.

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Abstract

Un procédé par lequel un point d'accès (AP) transmet une unité de données de protocole de couche physique (PPDU) de radio réveil (WUR) dans un système de réseau local sans fil, selon un mode de réalisation de la présente invention, comprend les étapes de : génération d'un préambule WUR comprenant une séquence pour une synchronisation temporelle et un champ SIG (signal) WUR ; et transmission de PPDU WUR comprenant le préambule WUR généré et un corps de trame WUR, la séquence pour la synchronisation temporelle générant de façon répétée la séquence répétitive minimale d'une longueur de N bits au moins deux fois, N étant un entier de 2 ou plus, et les N premiers bits du champ SIG WUR positionné à côté de la séquence pour synchronisation temporelle peuvent être définis à l'une des valeurs de bit autres que la valeur de bit correspondant à la séquence répétitive minimale parmi une pluralité de valeurs de bit qui peuvent être exprimées par N bits.
PCT/KR2018/001651 2017-03-06 2018-02-07 Procédé d'émission ou de réception de trame de radio de réveil dans un système de réseau local sans fil et appareil associé WO2018164380A1 (fr)

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Cited By (1)

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Publication number Priority date Publication date Assignee Title
US11824652B1 (en) * 2018-12-04 2023-11-21 Marvell Asia Pte Ltd Physical layer preamble for wireless local area networks

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120057506A1 (en) * 2009-05-22 2012-03-08 Praveen Kumar Large network association procedure in power efficient manner
US20130195209A1 (en) * 2008-07-09 2013-08-01 Arun Kumar Sharma Low Power Radio Communication System

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130195209A1 (en) * 2008-07-09 2013-08-01 Arun Kumar Sharma Low Power Radio Communication System
US20120057506A1 (en) * 2009-05-22 2012-03-08 Praveen Kumar Large network association procedure in power efficient manner

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
INTEL CORPORATION ET AL.: "Proposal for LP-WUR (Low- Power Wake-Up Receiver) Study Group", IEEE 802.11-16/0605R3, 17 May 2016 (2016-05-17), pages 1 - 14, XP055515110 *
MEDIATEK INC.: "LP WUR Wake-up Packet Identity Considerations", IEEE 802.11-16/0402R0, 13 March 2016 (2016-03-13), pages 1 - 9, XP068105310 *
ZTE: "Discussion of WUR Packets Design", IEEE 802.11-16/1504R0, 8 November 2016 (2016-11-08), pages 1 - 10, XP068110943 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11824652B1 (en) * 2018-12-04 2023-11-21 Marvell Asia Pte Ltd Physical layer preamble for wireless local area networks
US12143212B1 (en) 2018-12-04 2024-11-12 Marvell Asia Pte Ltd Physical layer preamble for wireless local area networks

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