The present specification relates to a method for transmitting an acknowledgment (ACK) signal using a multi-link in a wireless local area network (WLAN) system.
A wireless local area network (WLAN) has been improved in various ways. For example, the IEEE 802.11ax standard proposed an improved communication environment using orthogonal frequency division multiple access (OFDMA) and downlink multi-user multiple input multiple output (DL MU MIMO) techniques.
The present specification proposes a technical feature that can be utilized in a new communication standard. For example, the new communication standard may be an extreme high throughput (EHT) standard which is currently being discussed. The EHT standard may use an increased bandwidth, an enhanced PHY layer protocol data unit (PPDU) structure, an enhanced sequence, a hybrid automatic repeat request (HARQ) scheme, or the like, which is newly proposed. The EHT standard may be called the IEEE 802.11be standard.
A method performed by a station (STA) in a wireless local area network (WLAN) system according to various embodiments may include technical features related to a method of transmitting a response signal using a multi-link. A receiving station (STA) may receive, from a transmitting STA, a first signal through a first link and a second signal through a second link. The receiving STA may transmit, to the transmitting STA through the second link, a response signal related to whether the first and second signals are received. The response signal may include a first field related to that the response signal includes a response to whether a plurality of signals transmitted through a plurality of links are received.
According to an example of the present specification, the receiving STA may transmit a response signal including a plurality of responses to a plurality of signals received through a multi-link. Accordingly, even if the transmitting STA fails to receive the response signal in a specific link, since it can receive the response through another link, efficient communication can be performed. That is, since a more reliable and robust response signal can be transmitted and the number of retransmissions can be reduced, the effect of reducing transmission delay can be obtained. In addition, since the response signal may include information indicating that it includes responses to a plurality of links, the transmitting STA may obtain response information for data received in the current link from a response signal received in the other link based on the information contained in the response signal, or transmit response information of the other link.
In the present specification, “A or B” may mean “only A”, “only B” or “both A and B”. In other words, in the present specification, “A or B” may be interpreted as “A and/or B”. For example, in the present specification, “A, B, or C” may mean “only A”, “only B”, “only C”, or “any combination of A, B, C”.
A slash (/) or comma used in the present specification may mean “and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B, or C”.
In the present specification, “at least one of A and B” may mean “only A”, “only B”, or “both A and B”. In addition, in the present specification, the expression “at least one of A or B” or “at least one of A and/or B” may be interpreted as “at least one of A and B”.
In addition, in the present specification, “at least one of A, B, and C” may mean “only A”, “only B”, “only C”, or “any combination of A, B, and C”. In addition, “at least one of A, B, or C” or “at least one of A, B, and/or C” may mean “at least one of A, B, and C”.
In addition, a parenthesis used in the present specification may mean “for example”. Specifically, when indicated as “control information (EHT-signal)”, it may mean that “EHT-signal” is proposed as an example of the “control information”. In other words, the “control information” of the present specification is not limited to “EHT-signal”, and “EHT-signal” may be proposed as an example of the “control information”. In addition, when indicated as “control information (i.e., EHT-signal)”, it may also mean that “EHT-signal” is proposed as an example of the “control information”.
Technical features described individually in one figure in the present specification may be individually implemented, or may be simultaneously implemented.
The following example of the present specification may be applied to various wireless communication systems. For example, the following example of the present specification may be applied to a wireless local area network (WLAN) system. For example, the present specification may be applied to the IEEE 802.11a/g/n/ac standard or the IEEE 802.11ax standard. In addition, the present specification may also be applied to the newly proposed EHT standard or IEEE 802.11be standard. In addition, the example of the present specification may also be applied to a new WLAN standard enhanced from the EHT standard or the IEEE 802.11be standard. In addition, the example of the present specification may be applied to a mobile communication system. For example, it may be applied to a mobile communication system based on long term evolution (LTE) depending on a 3rd generation partnership project (3GPP) standard and based on evolution of the LTE. In addition, the example of the present specification may be applied to a communication system of a 5G NR standard based on the 3GPP standard.
Hereinafter, in order to describe a technical feature of the present specification, a technical feature applicable to the present specification will be described.
In the example of
For example, the STAs 110 and 120 may serve as an AP or a non-AP. That is, the STAs 110 and 120 of the present specification may serve as the AP and/or the non-AP.
STAs 110 and 120 of the present specification may support various communication standards together in addition to the IEEE 802.11 standard. For example, a communication standard (e.g., LTE, LTE-A, 5G NR standard) or the like based on the 3GPP standard may be supported. In addition, the STA of the present specification may be implemented as various devices such as a mobile phone, a vehicle, a personal computer, or the like. In addition, the STA of the present specification may support communication for various communication services such as voice calls, video calls, data communication, and self-driving (autonomous-driving), or the like.
The STAs 110 and 120 of the present specification may include a medium access control (MAC) conforming to the IEEE 802.11 standard and a physical layer interface for a radio medium.
The STAs 110 and 120 will be described below with reference to a sub-figure (a) of
The first STA 110 may include a processor 111, a memory 112, and a transceiver 113. The illustrated process, memory, and transceiver may be implemented individually as separate chips, or at least two blocks/functions may be implemented through a single chip.
The transceiver 113 of the first STA performs a signal transmission/reception operation. Specifically, an IEEE 802.11 packet (e.g., IEEE 802.11a/b/g/n/ac/ax/be, etc.) may be transmitted/received.
For example, the first STA 110 may perform an operation intended by an AP. For example, the processor 111 of the AP may receive a signal through the transceiver 113, process a reception (RX) signal, generate a transmission (TX) signal, and provide control for signal transmission. The memory 112 of the AP may store a signal (e.g., RX signal) received through the transceiver 113, and may store a signal (e.g., TX signal) to be transmitted through the transceiver.
For example, the second STA 120 may perform an operation intended by a non-AP STA. For example, a transceiver 123 of a non-AP performs a signal transmission/reception operation. Specifically, an IEEE 802.11 packet (e.g., IEEE 802.11a/b/g/n/ac/ax/be packet, etc.) may be transmitted/received.
For example, a processor 121 of the non-AP STA may receive a signal through the transceiver 123, process an RX signal, generate a TX signal, and provide control for signal transmission. A memory 122 of the non-AP STA may store a signal (e.g., RX signal) received through the transceiver 123, and may store a signal (e.g., TX signal) to be transmitted through the transceiver.
For example, an operation of a device indicated as an AP in the specification described below may be performed in the first STA 110 or the second STA 120. For example, if the first STA 110 is the AP, the operation of the device indicated as the AP may be controlled by the processor 111 of the first STA 110, and a related signal may be transmitted or received through the transceiver 113 controlled by the processor 111 of the first STA 110.
In addition, control information related to the operation of the AP or a TX/RX signal of the AP may be stored in the memory 112 of the first STA 110. In addition, if the second STA 120 is the AP, the operation of the device indicated as the AP may be controlled by the processor 121 of the second STA 120, and a related signal may be transmitted or received through the transceiver 123 controlled by the processor 121 of the second STA 120. In addition, control information related to the operation of the AP or a TX/RX signal of the AP may be stored in the memory 122 of the second STA 120.
For example, in the specification described below, an operation of a device indicated as a non-AP (or user-STA) may be performed in the first STA 110 or the second STA 120. For example, if the second STA 120 is the non-AP, the operation of the device indicated as the non-AP may be controlled by the processor 121 of the second STA 120, and a related signal may be transmitted or received through the transceiver 123 controlled by the processor 121 of the second STA 120. In addition, control information related to the operation of the non-AP or a TX/RX signal of the non-AP may be stored in the memory 122 of the second STA 120. For example, if the first STA 110 is the non-AP, the operation of the device indicated as the non-AP may be controlled by the processor 111 of the first STA 110, and a related signal may be transmitted or received through the transceiver 113 controlled by the processor 111 of the first STA 110. In addition, control information related to the operation of the non-AP or a TX/RX signal of the non-AP may be stored in the memory 112 of the first STA 110.
In the specification described below, a device called a (transmitting/receiving) STA, a first STA, a second STA, a STA1, a STA2, an AP, a first AP, a second AP, an AP1, an AP2, a (transmitting/receiving) terminal, a (transmitting/receiving) device, a (transmitting/receiving) apparatus, a network, or the like may imply the STAs 110 and 120 of
The aforementioned device/STA of the sub-figure (a) of
For example, the transceivers 113 and 123 illustrated in the sub-figure (b) of
A mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile subscriber unit, a user, a user STA, a network, a base station, a Node-B, an access point (AP), a repeater, a router, a relay, a receiving unit, a transmitting unit, a receiving STA, a transmitting STA, a receiving device, a transmitting device, a receiving apparatus, and/or a transmitting apparatus, which are described below, may imply the STAs 110 and 120 illustrated in the sub-figure (a)/(b) of
For example, a technical feature in which the receiving STA receives the control signal may be understood as a technical feature in which the control signal is received by means of the transceivers 113 and 123 illustrated in the sub-figure (a) of
Referring to the sub-figure (b) of
The processors 111 and 121 or processing chips 114 and 124 of
In the present specification, an uplink may imply a link for communication from a non-AP STA to an SP STA, and an uplink PPDU/packet/signal or the like may be transmitted through the uplink. In addition, in the present specification, a downlink may imply a link for communication from the AP STA to the non-AP STA, and a downlink PPDU/packet/signal or the like may be transmitted through the downlink.
An upper part of
Referring the upper part of
The BSS may include at least one STA, APs providing a distribution service, and a distribution system (DS) 210 connecting multiple APs.
The distribution system 210 may implement an extended service set (ESS) 240 extended by connecting the multiple BSSs 200 and 205. The ESS 240 may be used as a term indicating one network configured by connecting one or more APs 225 or 230 through the distribution system 210. The AP included in one ESS 240 may have the same service set identification (SSID).
A portal 220 may serve as a bridge which connects the wireless LAN network (i.e.EE 802.11) and another network (e.g., 802.X).
In the BSS illustrated in the upper part of
A lower part of
Referring to the lower part of
In S310, a STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, to access a network, the STA needs to discover a participating network. The STA needs to identify a compatible network before participating in a wireless network, and a process of identifying a network present in a particular area is referred to as scanning. Scanning methods include active scanning and passive scanning.
Although not shown in
After discovering the network, the STA may perform an authentication process in S320. The authentication process may be referred to as a first authentication process to be clearly distinguished from the following security setup operation in S340. The authentication process in S320 may include a process in which the STA transmits an authentication request frame to the AP and the AP transmits an authentication response frame to the STA in response. The authentication frames used for an authentication request/response are management frames.
The authentication frames may include information about an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), and a finite cyclic group.
The STA may transmit the authentication request frame to the AP. The AP may determine whether to allow the authentication of the STA based on the information included in the received authentication request frame. The AP may provide the authentication processing result to the STA via the authentication response frame.
When the STA is successfully authenticated, the STA may perform an association process in S330. The association process includes a process in which the STA transmits an association request frame to the AP and the AP transmits an association response frame to the STA in response. The association request frame may include, for example, information about various capabilities, a beacon listen interval, a service set identifier (SSID), a supported rate, a supported channel, RSN, a mobility domain, a supported operating class, a traffic indication map (TIM) broadcast request, and an interworking service capability. The association response frame may include, for example, information about various capabilities, a status code, an association ID (AID), a supported rate, an enhanced distributed channel access (EDCA) parameter set, a received channel power indicator (RCPI), a received signal-to-noise indicator (RSNI), a mobility domain, a timeout interval (association comeback time), an overlapping BSS scanning parameter, a TIM broadcast response, and a QoS map.
In S340, the STA may perform a security setup process. The security setup process in S340 may include a process of setting up a private key through four-way handshaking, for example, through an extensible authentication protocol over LAN (EAPOL) frame.
As illustrated, various types of PHY protocol data units (PPDUs) are used in IEEE a/g/n/ac standards. Specifically, an LTF and a STF include a training signal, a SIG-A and a SIG-B include control information for a receiving STA, and a data field includes user data corresponding to a PSDU (MAC PDU/aggregated MAC PDU).
As illustrated in
Hereinafter, a resource unit (RU) used for a PPDU is described. An RU may include a plurality of subcarriers (or tones). An RU may be used to transmit a signal to a plurality of STAs according to OFDMA. Further, an RU may also be defined to transmit a signal to one STA. An RU may be used for an STF, an LTF, a data field, or the like.
As illustrated in
As illustrated in the uppermost part of
The layout of the RUs in
Although
Similarly to
As illustrated in
Similarly to
As illustrated in
In the meantime, the fact that the specific number of RUs can be changed is the same as those of
The RU arrangement (i.e., RU location) shown in
One RU of the present specification may be allocated for a single STA (e.g., a single non-AP STA). Alternatively, a plurality of RUs may be allocated for one STA (e.g., a non-AP STA).
The RU described in the present specification may be used in uplink (UL) communication and downlink (DL) communication. For example, when UL-MU communication which is solicited by a trigger frame is performed, a transmitting STA (e.g., an AP) may allocate a first RU (e.g., 26/52/106/242-RU, etc.) to a first STA through the trigger frame, and may allocate a second RU (e.g., 26/52/106/242-RU, etc.) to a second STA. Thereafter, the first STA may transmit a first trigger-based PPDU based on the first RU, and the second STA may transmit a second trigger-based PPDU based on the second RU. The first/second trigger-based PPDU is transmitted to the AP at the same (or overlapped) time period.
For example, when a DL MU PPDU is configured, the transmitting STA (e.g., AP) may allocate the first RU (e.g., 26/52/106/242-RU, etc.) to the first STA, and may allocate the second RU (e.g., 26/52/106/242-RU, etc.) to the second STA. That is, the transmitting STA (e.g., AP) may transmit HE-STF, HE-LTF, and Data fields for the first STA through the first RU in one MU PPDU, and may transmit HE-STF, HE-LTF, and Data fields for the second STA through the second RU.
Information related to a layout of the RU may be signaled through HE-SIG-B.
As illustrated, an HE-SIG-B field 810 includes a common field 820 and a user-specific field 830. The common field 820 may include information commonly applied to all users (i.e., user STAs) which receive SIG-B. The user-specific field 830 may be called a user-specific control field. When the SIG-B is transferred to a plurality of users, the user-specific field 830 may be applied only any one of the plurality of users.
As illustrated in
The common field 820 may include RU allocation information of N*8 bits. For example, the RU allocation information may include information related to a location of an RU. For example, when a 20 MHz channel is used as shown in
An example of a case in which the RU allocation information consists of 8 bits is as follows.
As shown the example of
The example of Table 1 shows only some of RU locations capable of displaying the RU allocation information.
For example, the RU allocation information may include an example of Table 2 below.
“01000y2y1y0” relates to an example in which a 106-RU is allocated to the leftmost side of the 20 MHz channel, and five 26-RUs are allocated to the right side thereof. In this case, a plurality of STAs (e.g., user-STAs) may be allocated to the 106-RU, based on a MU-MIMO scheme. Specifically, up to 8 STAs (e.g., user-STAs) may be allocated to the 106-RU, and the number of STAs (e.g., user-STAs) allocated to the 106-RU is determined based on 3-bit information (y2y1y0). For example, when the 3-bit information (y2y1y0) is set to N, the number of STAs (e.g., user-STAs) allocated to the 106-RU based on the MU-MIMO scheme may be N+1.
In general, a plurality of STAs (e.g., user STAs) different from each other may be allocated to a plurality of RUs. However, the plurality of STAs (e.g., user STAs) may be allocated to one or more RUs having at least a specific size (e.g., 106 subcarriers), based on the MU-MIMO scheme.
As shown in
For example, when RU allocation is set to “01000y2y1y0”, a plurality of STAs may be allocated to the 106-RU arranged at the leftmost side through the MU-MIMO scheme, and five user STAs may be allocated to five 26-RUs arranged to the right side thereof through the non-MU MIMO scheme. This case is specified through an example of
For example, when RU allocation is set to “01000010” as shown in
The eight user fields may be expressed in the order shown in
The user fields shown in
Each user field may have the same size (e.g., 21 bits). For example, the user field of the first format (the first of the MU-MIMO scheme) may be configured as follows.
For example, a first bit (i.e., B0-B10) in the user field (i.e., 21 bits) may include identification information (e.g., STA-ID, partial AID, etc.) of a user STA to which a corresponding user field is allocated. In addition, a second bit (i.e., B11-B14) in the user field (i.e., 21 bits) may include information related to a spatial configuration. Specifically, an example of the second bit (i.e., B11-B14) may be as shown in Table 3 and Table 4 below.
As shown in Table 3 and/or Table 4, the second bit (e.g., B11-B14) may include information related to the number of spatial streams allocated to the plurality of user STAs which are allocated based on the MU-MIMO scheme. For example, when three user STAs are allocated to the 106-RU based on the MU-MIMO scheme as shown in
As shown in the example of Table 3 and/or Table 4, information (i.e., the second bit, B11-B14) related to the number of spatial streams for the user STA may consist of 4 bits. In addition, the information (i.e., the second bit, B11-B14) on the number of spatial streams for the user STA may support up to eight spatial streams. In addition, the information (i.e., the second bit, B11-B14) on the number of spatial streams for the user STA may support up to four spatial streams for one user STA.
In addition, a third bit (i.e., B15-18) in the user field (i.e., 21 bits) may include modulation and coding scheme (MCS) information. The MCS information may be applied to a data field in a PPDU including corresponding SIG-B.
An MCS, MCS information, an MCS index, an MCS field, or the like used in the present specification may be indicated by an index value. For example, the MCS information may be indicated by an index 0 to an index 11. The MCS information may include information related to a constellation modulation type (e.g., BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, etc.) and information related to a coding rate (e.g., ½, ⅔, ¾, ⅚e, etc.). Information related to a channel coding type (e.g., LCC or LDPC) may be excluded in the MCS information.
In addition, a fourth bit (i.e., B19) in the user field (i.e., 21 bits) may be a reserved field.
In addition, a fifth bit (i.e., B20) in the user field (i.e., 21 bits) may include information related to a coding type (e.g., BCC or LDPC). That is, the fifth bit (i.e., B20) may include information related to a type (e.g., BCC or LDPC) of channel coding applied to the data field in the PPDU including the corresponding SIG-B.
The aforementioned example relates to the user field of the first format (the format of the MU-MIMO scheme). An example of the user field of the second format (the format of the non-MU-MIMO scheme) is as follows.
A first bit (e.g., B0-B10) in the user field of the second format may include identification information of a user STA. In addition, a second bit (e.g., B11-B13) in the user field of the second format may include information related to the number of spatial streams applied to a corresponding RU. In addition, a third bit (e.g., B14) in the user field of the second format may include information related to whether a beamforming steering matrix is applied. A fourth bit (e.g., B15-B18) in the user field of the second format may include modulation and coding scheme (MCS) information. In addition, a fifth bit (e.g., B19) in the user field of the second format may include information related to whether dual carrier modulation (DCM) is applied. In addition, a sixth bit (i.e., B20) in the user field of the second format may include information related to a coding type (e.g., BCC or LDPC).
TB PPDUs 1041 and 1042 may be transmitted at the same time period, and may be transmitted from a plurality of STAs (e.g., user STAs) having AIDs indicated in the trigger frame 1030. An ACK frame 1050 for the TB PPDU may be implemented in various forms.
A specific feature of the trigger frame is described with reference to
Each field shown in
A frame control field 1110 of
In addition, an RA field 1130 may include address information of a receiving STA of a corresponding trigger frame, and may be optionally omitted. A TA field 1140 may include address information of a STA (e.g., an AP) which transmits the corresponding trigger frame. A common information field 1150 includes common control information applied to the receiving STA which receives the corresponding trigger frame. For example, a field indicating a length of an L-SIG field of an uplink PPDU transmitted in response to the corresponding trigger frame or information for controlling content of a SIG-A field (i.e., HE-SIG-A field) of the uplink PPDU transmitted in response to the corresponding trigger frame may be included. In addition, as common control information, information related to a length of a CP of the uplink PPDU transmitted in response to the corresponding trigger frame or information related to a length of an LTF field may be included.
In addition, per user information fields 1160#1 to 1160#N corresponding to the number of receiving STAs which receive the trigger frame of
In addition, the trigger frame of
Each of the per user information fields 1160#1 to 1160#N shown in
A length field 1210 illustrated has the same value as a length field of an L-SIG field of an uplink PPDU transmitted in response to a corresponding trigger frame, and a length field of the L-SIG field of the uplink PPDU indicates a length of the uplink PPDU. As a result, the length field 1210 of the trigger frame may be used to indicate the length of the corresponding uplink PPDU.
In addition, a cascade identifier field 1220 indicates whether a cascade operation is performed. The cascade operation implies that downlink MU transmission and uplink MU transmission are performed together in the same TXOP. That is, it implies that downlink MU transmission is performed and thereafter uplink MU transmission is performed after a pre-set time (e.g., SIFS). During the cascade operation, only one transmitting device (e.g., AP) may perform downlink communication, and a plurality of transmitting devices (e.g., non-APs) may perform uplink communication.
A CS request field 1230 indicates whether a wireless medium state or a NAV or the like is necessarily considered in a situation where a receiving device which has received a corresponding trigger frame transmits a corresponding uplink PPDU.
An HE-SIG-A information field 1240 may include information for controlling content of a SIG-A field (i.e., HE-SIG-A field) of the uplink PPDU in response to the corresponding trigger frame.
A CP and LTF type field 1250 may include information related to a CP length and LTF length of the uplink PPDU transmitted in response to the corresponding trigger frame. A trigger type field 1260 may indicate a purpose of using the corresponding trigger frame, for example, typical triggering, triggering for beamforming, a request for block ACK/NACK, or the like.
It may be assumed that the trigger type field 1260 of the trigger frame in the present specification indicates a trigger frame of a basic type for typical triggering. For example, the trigger frame of the basic type may be referred to as a basic trigger frame.
A user identifier field 1310 of
In addition, an RU allocation field 1320 may be included. That is, when the receiving STA identified through the user identifier field 1310 transmits a TB PPDU in response to the trigger frame, the TB PPDU is transmitted through an RU indicated by the RU allocation field 1320. In this case, the RU indicated by the RU allocation field 1320 may be an RU shown in
The subfield of
In addition, the subfield of
Hereinafter, a UL OFDMA-based random access (UORA) scheme will be described.
A transmitting STA (e.g., an AP) may allocate six RU resources through a trigger frame as shown in
In the example of
Specifically, since the STA1 of
The 2.4 GHz band may be called in other terms such as a first band. In addition, the 2.4 GHz band may imply a frequency domain in which channels of which a center frequency is close to 2.4 GHz (e.g., channels of which a center frequency is located within 2.4 to 2.5 GHz) are used/supported/defined.
A plurality of 20 MHz channels may be included in the 2.4 GHz band. 20 MHz within the 2.4 GHz may have a plurality of channel indices (e.g., an index 1 to an index 14). For example, a center frequency of a 20 MHz channel to which a channel index 1 is allocated may be 2.412 GHz, a center frequency of a 20 MHz channel to which a channel index 2 is allocated may be 2.417 GHz, and a center frequency of a 20 MHz channel to which a channel index N is allocated may be ( 2.407+0.005*N) GHz. The channel index may be called in various terms such as a channel number or the like. Specific numerical values of the channel index and center frequency may be changed.
The 5 GHz band may be called in other terms such as a second band or the like. The 5 GHz band may imply a frequency domain in which channels of which a center frequency is greater than or equal to 5 GHz and less than 6 GHz (or less than 5.9 GHz) are used/supported/defined. Alternatively, the 5 GHz band may include a plurality of channels between 4.5 GHz and 5.5 GHz. A specific numerical value shown in
A plurality of channels within the 5 GHz band include an unlicensed national information infrastructure (UNII)-1, a UNII-2, a UNII-3, and an ISM. The INII-1 may be called UNIT Low. The UNII-2 may include a frequency domain called UNIT Mid and UNIT-2Extended. The UNII-3 may be called UNII-Upper.
A plurality of channels may be configured within the 5 GHz band, and a bandwidth of each channel may be variously set to, for example, 20 MHz, 40 MHz, 80 MHz, 160 MHz, or the like. For example, 5170 MHz to 5330 MHz frequency domains/ranges within the UNII-1 and UNII-2 may be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency domains/ranges may be divided into four channels through a 40 MHz frequency domain. The 5170 MHz to 5330 MHz frequency domains/ranges may be divided into two channels through an 80 MHz frequency domain. Alternatively, the 5170 MHz to 5330 MHz frequency domains/ranges may be divided into one channel through a 160 MHz frequency domain.
The 6 GHz band may be called in other terms such as a third band or the like. The 6 GHz band may imply a frequency domain in which channels of which a center frequency is greater than or equal to 5.9 GHz are used/supported/defined. A specific numerical value shown in
For example, the 20 MHz channel of
Accordingly, an index (or channel number) of the 2 MHz channel of
Although 20, 40, 80, and 160 MHz channels are illustrated in the example of
Hereinafter, a PPDU transmitted/received in a STA of the present specification will be described.
The PPDU 1800 depicted in
The subfields 1801 to 1810 depicted in
The subcarrier spacing of the L-LTF, L-STF, L-SIG, and RL-SIG fields 1801, 1802, 1803, and 1804 of
The SIG A and/or SIG B fields of
In the PPDU of
The L-SIG field of
For example, the transmitting STA may apply BCC encoding based on a ½ coding rate to the 24-bit information of the L-SIG field. Thereafter, the transmitting STA may obtain a BCC coding bit of 48 bits. BPSK modulation may be applied to the 48-bit coding bit, thereby generating 48 BPSK symbols. The transmitting STA may map the 48 BPSK symbols to positions except for a pilot subcarrier {subcarrier index −21, −7, +7, +21} and a DC subcarrier {subcarrier index 0}. As a result, the 48 BPSK symbols may be mapped to subcarrier indices −26 to −22, −20 to −8, −6 to −1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA may additionally map a signal of {−1, −1, −1, 1} to a subcarrier index {−28, −27, +27, +28}. The aforementioned signal may be used for channel estimation on a frequency domain corresponding to {−28, −27, +27, +28}.
The transmitting STA may generate an RL-SIG which is identical to the L-SIG. BPSK modulation may be applied to the RL-SIG. The receiving STA may figure out that the RX PPDU is the HE PPDU or the EHT PPDU, based on the presence of the RL-SIG.
After RL-SIG of
A symbol consecutive to the RL-SIG (e.g., U-SIG) may include information of N bits, and may include information for identifying the type of the EHT PPDU. For example, the U-SIG may be configured based on two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for U-SIG may have a duration of 4 us. Each symbol of the U-SIG may be used to transmit 26-bit information. For example, each symbol of the U-SIG may be transmitted/received based on 52 data tones and 4 pilot tones.
Through the U-SIG (or U-SIG field), for example, A-bit information (e.g., 52 un-coded bits) may be transmitted. A first symbol of the U-SIG may transmit first X-bit information (e.g., 26 un-coded bits) of the A-bit information, and a second symbol of the U-SIG may transmit the remaining Y-bit information (e.g., 26 un-coded bits) of the A-bit information. For example, the transmitting STA may obtain 26 un-coded bits included in each U-SIG symbol. The transmitting STA may perform convolutional encoding (i.e., BCC encoding) based on a rate of R=½ to generate 52-coded bits, and may perform interleaving on the 52-coded bits. The transmitting STA may perform BPSK modulation on the interleaved 52-coded bits to generate 52 BPSK symbols to be allocated to each U-SIG symbol. One U-SIG symbol may be transmitted based on 65 tones (subcarriers) from a subcarrier index −28 to a subcarrier index +28, except for a DC index 0. The 52 BPSK symbols generated by the transmitting STA may be transmitted based on the remaining tones (subcarriers) except for pilot tones, i.e., tones −21, −7, +7, +21.
For example, the A-bit information (e.g., 52 un-coded bits) generated by the U-SIG may include a CRC field (e.g., a field having a length of 4 bits) and a tail field (e.g., a field having a length of 6 bits). The CRC field and the tail field may be transmitted through the second symbol of the U-SIG. The CRC field may be generated based on 26 bits allocated to the first symbol of the U-SIG and the remaining 16 bits except for the CRC/tail fields in the second symbol, and may be generated based on the conventional CRC calculation algorithm. In addition, the tail field may be used to terminate trellis of a convolutional decoder, and may be set to, for example, “000000”.
The A-bit information (e.g., 52 un-coded bits) transmitted by the U-SIG (or U-SIG field) may be divided into version-independent bits and version-dependent bits. For example, the version-independent bits may have a fixed or variable size. For example, the version-independent bits may be allocated only to the first symbol of the U-SIG, or the version-independent bits may be allocated to both of the first and second symbols of the U-SIG. For example, the version-independent bits and the version-dependent bits may be called in various terms such as a first control bit, a second control bit, or the like.
For example, the version-independent bits of the U-SIG may include a PHY version identifier of 3 bits. For example, the PHY version identifier of 3 bits may include information related to a PHY version of a TX/RX PPDU. For example, a first value of the PHY version identifier of 3 bits may indicate that the TX/RX PPDU is an EHT PPDU. In other words, when the transmitting STA transmits the EHT PPDU, the PHY version identifier of 3 bits may be set to a first value. In other words, the receiving STA may determine that the RX PPDU is the EHT PPDU, based on the PHY version identifier having the first value.
For example, the version-independent bits of the U-SIG may include a UL/DL flag field of 1 bit. A first value of the UL/DL flag field of 1 bit relates to UL communication, and a second value of the UL/DL flag field relates to DL communication.
For example, the version-independent bits of the U-SIG may include information related to a TXOP length and information related to a BSS color ID.
For example, when the EHT PPDU is classified into various types (e.g., EHT PPDU supporting SU, EHT PPDU supporting MU, EHT PPDU related to Trigger Frame, EHT PPDU related to Extended Range transmission, etc.), information related to the type of the EHT PPDU may be included in version-independent bits or version-dependent bits of the U-SIG.
For example, the U-SIG field includes 1) a bandwidth field including information related to a bandwidth, 2) a field including information related an MCS scheme applied to the SIG-B, 3) a dual subcarrier modulation in the SIG-B (i.e., an indication field including information related to whether the dual subcarrier modulation) is applied, 4) a field including information related to the number of symbols used for the SIG-B, 5) a field including information on whether the SIG-B is generated over the entire band, 6) a field including information related to a type of the LTF/STF, and/or 7) information related to a field indicating a length of the LTF and the CP.
The SIG-B of
An STF of
The EHT-STF of
Information related to the type of STF and/or LTF (including information related to GI applied to the LTF) may be included in the SIG A field and/or the SIG B field of
The PPDU of
The PPDU of
A receiving STA may determine a type of an RX PPDU as the EHT PPDU, based on the following aspect. For example, the RX PPDU may be determined as the EHT PPDU: 1) when a first symbol after an L-LTF signal of the RX PPDU is a BPSK symbol; 2) when RL-SIG in which the L-SIG of the RX PPDU is repeated is detected; and 3) when a result of applying “module 3” to a value of a length field of the L-SIG of the RX PPDU is detected as “0”. When the RX PPDU is determined as the EHT PPDU, the receiving STA may detect a type of the EHT PPDU (e.g., an SU/MU/Trigger-based/Extended Range type), based on bit information included in a symbol after the RL-SIG of
For example, the receiving STA may determine the type of the RX PPDU as the EHT PPDU, based on the following aspect. For example, the RX PPDU may be determined as the HE PPDU: 1) when a first symbol after an L-LTF signal is a BPSK symbol; 2) when RL-SIG in which the L-SIG is repeated is detected; and 3) when a result of applying “module 3” to a value of a length field of the L-SIG is detected as “1” or “2”.
For example, the receiving STA may determine the type of the RX PPDU as a non-HT, HT, and VHT PPDU, based on the following aspect. For example, the RX PPDU may be determined as the non-HT, HT, and VHT PPDU: 1) when a first symbol after an L-LTF signal is a BPSK symbol; and 2) when RL-SIG in which L-SIG is repeated is not detected. In addition, even if the receiving STA detects that the RL-SIG is repeated, when a result of applying “modulo 3” to the length value of the L-SIG is detected as “0”, the RX PPDU may be determined as the non-HT, HT, and VHT PPDU.
In the following example, a signal represented as a (TX/RX/UL/DL) signal, a (TX/RX/UL/DL) frame, a (TX/RX/UL/DL) packet, a (TX/RX/UL/DL) data unit, (TX/RX/UL/DL) data, or the like may be a signal transmitted/received based on the PPDU of
Each device/STA of the sub-figure (a)/(b) of
A processor 610 of
A memory 620 of
Referring to
Referring to
Hybrid automatic repeat request (HARQ) is a scheme of using a forward error correcting (FEC) scheme and an automatic error request (ARQ) scheme together. Unlike general automatic repeat request (ARQ), HARQ may additionally transmit information related to an FEC code capable of detecting an error. The receiving terminal may attempt error recovery through the FEC code, and when the error recovery fails, the receiving terminal may request retransmission from the transmitting terminal through ARQ. HARQ is used in standards such as high-speed downlink packet access (HSDPA), IEEE 802.16e, and long term evolution (LTE), but HARQ has never been used in a contention-based wireless local area network (WLAN) environment.
In extreme high throughput (EHT), a standard being discussed after IEEE 802.11ax, the introduction of HARQ is being considered. When HARQ is introduced, in a low signal to noise ratio (SNR) environment, that is, in an environment where the distance between the transmitting terminal and the receiving terminal is long, coverage can be widened, and in a high SNR environment, higher throughput can be obtained.
The terminal described below may be the apparatus of
In extremely high throughput (EHT), a standard being discussed after 802.11ax, a multi-band environment using one or more bands simultaneously is being considered. When the AP or STA supports multi-band or multi-link, the AP or STA may use one or more bands (for example, 2.4 GHz, 5 GHz, 6 GHz, 60 GHz, etc.) simultaneously or alternately. Multi-band/multi-link transmission can be classified into two types as shown in
Referring to
In the existing single band/single link situation, the ACK frame may be transmitted through the band/link through which data is transmitted. Accordingly, when transmission is performed in two or more bands/links, the ACK frame for data transmitted in each link may operate link-specifically. The ACK frame may be lost due to a power imbalance problem or a collision problem between the AP and the STA. In a multi-band/link environment, time resources can be used more efficiently by designing a reliable ACK transmission procedure using a multi-band/link.
Hereinafter, a BA frame transmission method using a multi-band/link environment will be described. Hereinafter, for reliable BA frame transmission, a BA frame including a transmission result of another band/link may be copied and transmitted in each band/link. Hereinafter, an ACK frame configuration and transmission method for a case in which multi-band/link transmission is synchronous, that is, when transmission of each band is aligned, and asynchronous, that is, when transmitted independently, will be described. For example, synchronous transmission method having the same transmission time start point and an end point in different bands/links, and an asynchronous transmission method having different transmission time start points and different end points in different bands/links may be described. Since the receiving terminal notifies the transmitting terminal of a problem occurring in transmission and reception of frames in a specific band or link through another band or link, an effect of efficiently using radio resources can be obtained.
Hereinafter, a block ACK (BA) frame may be proposed as an example of a response to a data frame, but a response to the data frame may be configured in various other forms. Hereinafter, an ACK frame, a BA frame, a compressed BA frame, and the like may be used, but for convenience of the description, some embodiments may be described based on the BA frame.
Hereinafter, it will be described in the form of a multi-band, but the frequency band may be configured in various other forms. In the present specification, terms such as multi-band, multi-link, and the like may be used, but for convenience of the description below, some embodiments may be described based on multi-band. Multi-band may have the same meaning as multi-link. For example, in multi-band, band A and band B may mean different links within the same frequency band.
1. Synchronous multi-band transmission
Referring to
An STA that has received a data frame in band A and band B may configure BlockACK information based on a result of decoding and CRC checking of the received data, the BA frame may be configured by merging the BlockACK information of the band A and the band B. The merged BA frame may be duplicated in band A and band B and transmitted to the AP. For example, the BA frame may include both a BA for data 1 transmitted in band A (i.e., ACK1) and a BA for data 2 transmitted in band B (i.e., ACK2). Although this embodiment assumes downlink (DL) transmission, the same method may be used for uplink (UL) transmission.
Referring to
In the embodiments of
A STA that has received data in bands A and B may configure BA information based on a result of decoding and CRC checking of the received data, and may configure a BA frame by merging BA information.
2. Asynchronous multi-band transmission
Referring to
An STA that has received a data frame in an arbitrary band may configure a BA frame by merging BA information for data previously received in another band. For example, the receiving STA may configure a BA frame by merging BA information for data 2 received in band B and BA information for data 1 previously received in band A. The merged BA frame may be transmitted to the AP in the corresponding band. For example, the merged BA frame may be transmitted in band B in which data 2 is received. Although this embodiment assumes downlink (DL) transmission, the same method may be used for uplink (UL) transmission.
Referring to
For example,
The receiving STA may configure a BA frame by merging BA information on data in a band/link that has recently received data and BA information on data previously transmitted in another band/link. Data for which the transmitting STA requests an ACK may include data previously transmitted in the same band/link. For example, data 3 to be transmitted in band A may include information related to an ACK request for data 1 previously transmitted in band A. The BA frame may be transmitted through a band/link that has recently received data. Although this embodiment assumes downlink (DL) transmission, the same method may be used for uplink (UL) transmission.
For example, the receiving STA may configure a BA frame by merging BA information for data received in different bands/links, and transmit the BA frame in one band/link (for example,
3. Frame format
For multi-band/link ACK, a field that can inform the receiving STA about which data frame the transmitting STA will request BA (i.e., information related to whether it is received or not) may be required.
Referring to
A MAC header in a data frame of a PPDU used for data transmission may include a fragment number and a sequence number of a frame for which ACK is requested. Upon receiving the data frame, the receiving STA may obtain information about the frame for which the ACK is requested included in the MAC header, and transmit a BA frame including an ACK (i.e., information related to whether it is received or not) for the frame for which the ACK is requested. For example, a field capable of informing the receiving STA about which data frame the transmitting STA requests BA (i.e., information related to whether or not it is received) may be defined for multi-band/link ACK. As a field that can inform the receiving STA about which data frame the transmitting STA requests BA (i.e., information related to whether it is received or not) for which data frame, for example, the EHT ACK control field may be defined, otherwise, another reserved field may be used. The position of a field that can inform the receiving STA about which data frame the transmitting STA requests BA (i.e., information related to whether it is received or not) is not limited.
Since the data frame includes the ACK for the frame for which the ACK is requested (i.e., information related to whether it is received or not), there is an effect that the transmitting STA can specify the data frame from which the response information is to be obtained. Accordingly, there is an effect that the transmitting STA can efficiently determine whether to retransmit.
Referring to
Since a data frame includes the ACK (that is, information related to whether it is received or not) for the frame for which the ACK is requested, there is an effect that the transmitting STA can specify the data frame from which to obtain response information. Accordingly, there is an effect that the transmitting STA can efficiently determine whether to retransmit.
Referring to
Since the data frame includes an ACK (i.e., information related to whether it is received or not) for the frame for which ACK is requested, there is an effect that the transmitting STA can specify the data frame from which the response information is to be obtained. Accordingly, there is an effect that the transmitting STA can efficiently determine whether to retransmit.
Referring to
When the receiving STA receives the data frame, it may need to transmit a BlockAck frame including ACK information of the solicited data frame. For example, upon receiving a PPDU including data, the receiving STA may transmit a BA frame including ACK information for data frames for which a response, related to whether it is received, is requested. The receiving STA may obtain information on data frames for which a response related to whether it is received is requested through a data frame or a BAR frame.
The BA frame may include information indicating that the BA frame includes BA information for multi-band/link. For example, it is possible to indicate that the BA frame is an EHT multi-band/link BA frame by using the BA type spare field included in the BA frame. For example, if the BA type spare field included in the BA frame has a specific value, the BA frame may include information that the BA frame is an EHT multi-band/link BA frame. For example, if the BA type included in the BA frame has a value of 15, it may mean that the BA frame is a BA frame including ACK information for multi-band/link.
The BA Information field may include information on a fragment number and a sequence number of data for which a response related to whether is received or not per traffic identifier (TID) is requested. For example, the fragment number and the sequence number may be included in the Block Ack Starting Sequence Control field. ACK information (i.e., whether it is received or not) of data for which a response related to whether it is received is requested may be included in the BlockAck Bitmap field. When ACK information needs to be transmitted for one or more TIDs, the Per TID info field may include information on TIDs of data. The BlockAck number field may include information on which fragment and/or sequence the ACK is.
By including information that the BA frame includes responses to a plurality of links, it could be obtained an effect that the transmitting STA can obtain response information for data received in the current link from a response signal received from another link based on the information included in the response signal, or deliver response information of another link.
Information that the BA frame includes ACK information for a plurality of bands/links may be transmitted based on a new field or a new value, or may be included in other unused fields (for example, a reserved field, etc.). That is, the position of the field including information indicating that the BA frame includes ACK information for a plurality of bands/links is not limited.
The transmitting STA and the receiving STA may negotiate on a method for an ACK response. Negotiation may be performed through an action frame, or may be performed through an arbitrary field included in each data frame. Alternatively, negotiation on the method for the ACK response may be performed using an existing field included in the data frame.
By including information that the BA frame includes responses to a plurality of links, it could be obtained an effect that the transmitting STA can obtain response information for data received in the current link from a response signal received from another link based on the information included in the response signal, or deliver response information of another link.
Referring to
Specifically, before receiving a signal from the transmitting STA (S4010), the receiving STA may perform association with the transmitting STA.
The receiving STA may receive a plurality of PPDUs from the transmitting STA (S4010). The receiving STA may decode the received PPDU and may deliver the decoding result to the MAC layer. The MAC layer of the receiving STA may perform a CRC check.
For example, the receiving STA may receive a first signal through a first link and a second signal through a second link from the transmitting STA. The first signal and the second signal may be a PPDU including a data frame.
The PPDU may include a PHY header (PHYHDR) and a physical service data unit (PSDU). PSDU may include MPDU delimiter, MPDU, and Padding fields. The MPDU (or data frame) may include a MAC header, a frame body, and an FCS field. The MAC header may include an EHT ACK control field. The EHT ACK control field may include a Fragment Number (Frag. Number) field and a Sequence Number (Seq. Number) field.
For example, a MAC header in a data frame of a PPDU used for data transmission may include a fragment number and a sequence number of a frame for which ACK is requested. Upon receiving the data frame, the receiving STA may obtain information on the frame for which ACK is requested included in the MAC header, and may transmit a BA frame including an ACK (i.e., information related to whether it is received) for the frame for which the ACK is requested. For example, a field that can inform the receiving STA about which data frame the transmitting STA requests BA (i.e. information related to whether it is received or not) for multi-band/link ACK may be defined. As a field that can inform the receiving STA about which data frame the transmitting STA requests BA for which data frame, for example, the EHT ACK control field may be defined, or, Reserved fields may be used. As a field that can inform the receiving STA about which data frame the transmitting STA requests BA (i.e., information related to whether it is received or not) for, for example, an EHT ACK control field may be defined, or another reserved field may be used. The position of a field that can inform the receiving STA about which data frame the transmitting STA requests BA (i.e., information related to whether it is received) is not limited.
For example, a PPDU including an A-MPDU may include a plurality of A-MPDU subframes. In the MAC header of the A-MPDU subframe, a field (for example, an EHT ACK control field) that can inform the receiving STA about which data frame the transmitting STA requests BA (i.e., information related to whether it is received or not) may be included. The EHT ACK control field may be included in at least one A-MPDU subframe. For example, the EHT ACK control field may be included in only one A-MPDU subframe, in all A-MPDU subframes, or in some A-MPDU subframes.
For example, the PSDU may include a field (for example, an EHT ACK control header) related to control information for the entire A-MPDU. The EHT ACK control header may be included in the PSDU, and the EHT ACK control header may include information related to which data frame the transmitting STA requests a BA (i.e., information related to whether it is received or not).
The receiving STA may receive the BAR frame (S4020). For example, the BAR frame may include information related to the ACK request for the first signal and the second signal. The step of BAR frame transmission may be omitted.
For example, information related to the ACK request for the first signal and the second signal may be included in at least one of the data frames and the BAR frame. That is, when the data frame includes information related to the ACK request for the first signal and the second signal, the BAR frame may not include information related to the ACK request for the first signal and the second signal. That is, when the BAR frame includes information related to the ACK request for the first signal and the second signal, the data frame may not include information related to the ACK request for the first signal and the second signal.
The receiving STA may transmit response signals to the plurality of signals (S4030). For example, the receiving STA may transmit a response signal related to whether the first and second signals are received to the transmitting STA through the second link. For example, the response signal may include a field related to whether the response signal includes a response to whether a plurality of signals transmitted through a plurality of links are received.
For example, the response signal may be a BA frame. The BA frame may be a PPDU including information related to whether data is received. That is, the response signal may be a PPDU used as a BA frame.
The PPDU used as the BA frame may include a PHY header (PHYHDR) and a physical service data unit (PSDU). PSDU may include MPDU delimiter, MPDU, and Padding fields. The MPDU may include a MAC header, a frame body, and an FCS field. The MAC header may include Frame Control, Duration, RA, TA, BA Control, and BA Information fields. The BA Control field may include BA ACK policy, BA Type, Reserved, and TID information (INFO) fields. The BA Information field may include Per TID info, BlockAck Number, Block Ack Starting Sequence Control, and BlockAck Bitmap fields. The Block Ack Starting Sequence Control field may include a Fragment Number and a Sequence Number field.
For example, upon receiving the data frame, the receiving STA may need to transmit a BlockAck frame including ACK information of the solicited data frame. For example, upon receiving a PPDU including data, the receiving STA may transmit a BA frame including ACK information for data frames for which a response related to whether it is received or not is requested. The receiving STA may obtain, through a data frame or a BAR frame, information on data frames for which a response related to whether it is received or not is requested.
The BA frame may include information informing that the BA frame includes BA information for multi-band/link. For example, it is possible to indicate that the BA frame is an EHT multi-band/link BA frame by using the BA type spare field included in the BA frame. For example, if the BA type spare field included in the BA frame has a specific value, the BA frame may include information that the BA frame is an EHT multi-band/link BA frame. For example, if the BA type included in the BA frame has a value of 15, it may mean that the BA frame is a BA frame including ACK information for multi-band/link.
The BA Information field may include information on a fragment number and a sequence number of data for which a response related to whether it is received or not per traffic identifier (TID). For example, the fragment number and the sequence number may be included in the Block Ack Starting Sequence Control field. ACK (i.e., whether it is received or not) information of data for which a response related to whether it is received or not is requested may be included in the BlockAck Bitmap field. When ACK information needs to be transmitted for one or more TIDs, the Per TID info field may include information on TIDs of data. The BlockAck number field may include information on which fragment and/or sequence the ACK is.
For example, when the receiving STA receives a request for ACKs for all fragments of the same sequence, the BA Information field may include information on a sequence number and may include a Concatenated BlockAck Bitmap field. For example, the Concatenated BlockAck Bitmap field may include a BlockAck Bitmap field for a plurality of fragments. Information that the BA frame includes ACK information for a plurality of bands/links may be transmitted based on a new field or a new value, and may be included in other unused fields (for example, reserved fields, etc.). That is, the position of the field including information informing that the BA frame includes ACK information for a plurality of bands/links is not limited.
The transmitting STA and the receiving STA may perform negotiation on a method for an ACK response. Negotiation may be performed through an action frame, or may be performed through an arbitrary field included in each data frame. Alternatively, negotiation on the method for the ACK response may be performed using an existing field included in the data frame.
Referring to
Specifically, before receiving a signal from the transmitting STA (S4110), the transmitting STA may perform association with the receiving STA. The receiving STA may receive data (for example, TCP/IP PDUs, etc.) to be transmitted from an upper layer, and may generate an MPDU in the MAC layer that includes information on the received data and data to request ACK information from the receiving STA. The PHY layer of the transmitting STA may generate a PPDU by combining the MPDU (or A-MPDU) and the PHY header.
The transmitting STA may transmit a plurality of signals through a multi-band/link (S4110). For example, the transmitting STA may transmit a first signal through a first link and a second signal through a second link to the receiving STA. The first signal and the second signal may be a PPDU including a data frame.
The PPDU may include a PHY header (PHYHDR) and a physical service data unit (PSDU). PSDU may include MPDU delimiter, MPDU, and Padding fields. The MPDU (or data frame) may include a MAC header, a frame body, and an FCS field. The MAC header may include an EHT ACK control field. The EHT ACK control field may include a Fragment Number (Frag. Number) field and a Sequence Number (Seq. Number) field.
For example, a MAC header in a data frame of a PPDU used for data transmission may include a fragment number and a sequence number of a frame for which ACK is requested. Upon receiving the data frame, the receiving STA may obtain information about the frame for which the ACK is requested included in the MAC header, and may transmit a BA frame including the ACK for the frame for which the ACK is requested (i.e., information related to whether it is received or not). For example, a field capable of informing the receiving STA about which data frame the transmitting STA requests BA (i.e., information related to whether it is received or not) may be defined for multi-band/link ACK. As a field that can inform the receiving STA about which data frame the transmitting STA requests BA (i.e., information related to whether it is received or not), for example, the EHT ACK control field may be defined, or, another reserved field may be used. The position of a field that can inform the receiving STA about which data frame the transmitting STA requests BA (i.e., information related to whether it is received or not) is not limited.
For example, a PPDU including an A-MPDU may include a plurality of A-MPDU subframes. The MAC header of the A-MPDU subframe may include a field (for example, an EHT ACK control field) that can inform the receiving STA about which data frame the transmitting STA requests BA (i.e. information related to whether it is received or not). The EHT ACK control field may be included in at least one A-MPDU subframe. For example, the EHT ACK control field may be included in only one A-MPDU subframe, in all A-MPDU subframes, or in some A-MPDU subframes.
For example, the PSDU may include a field (for example, an EHT ACK control header) related to control information for the entire A-MPDU. The EHT ACK control header may be included in the PSDU, and the EHT ACK control header may include information related to which data frame the transmitting STA requests a BA (i.e., information related to whether it is received or not).
The transmitting STA may transmit a BAR frame (S4120). For example, the BAR frame may include information related to the ACK request for the first signal and the second signal. The step of BAR frame transmission may be omitted.
For example, information related to the ACK request for the first signal and the second signal may be included in at least one of the data frame and the BAR frame. That is, when the data frame includes information related to the ACK request for the first signal and the second signal, the BAR frame may not include information related to the ACK request for the first signal and the second signal. That is, when the BAR frame includes information related to the ACK request for the first signal and the second signal, the data frame may not include information related to the ACK request for the first signal and the second signal.
The transmitting STA may receive response signals to the plurality of signals (S4130). For example, the transmitting STA may receive a response signal related to whether the first and second signals are received from the receiving STA through the second link. For example, the response signal may include a field related to whether the response signal includes a response to whether a plurality of signals transmitted through a plurality of links are received.
For example, the response signal may be a BA frame. The BA frame may be a PPDU including information related to whether data is received. That is, the response signal may be a PPDU used as a BA frame.
The PPDU used as the BA frame may include a PHY header (PHYHDR) and a physical service data unit (PSDU). PSDU may include MPDU delimiter, MPDU, and Padding fields. The MPDU may include a MAC header, a frame body, and an FCS field. The MAC header may include Frame Control, Duration, RA, TA, BA Control, and BA Information fields. The BA Control field may include BA ACK policy, BA Type, Reserved, and TID information (INFO) fields. The BA Information field may include Per TID info, BlockAck Number, Block Ack Starting Sequence Control, and BlockAck Bitmap fields. The Block Ack Starting Sequence Control field may include a Fragment Number and a Sequence Number field.
For example, upon receiving the data frame, the receiving STA may need to transmit a BlockAck frame including ACK information of the solicited data frame. For example, upon receiving a PPDU including data, the receiving STA may transmit a BA frame including ACK information for data frames for which a response related to whether it is received or not is requested. The receiving STA may obtain information on data frames for which a response related to whether it is received is requested through a data frame or a BAR frame.
The BA frame may include information informing that the BA frame includes BA information for multi-band/link. For example, it is possible to indicate that the BA frame is an EHT multi-band/link BA frame by using the BA type spare field included in the BA frame. For example, if the BA type spare field included in the BA frame has a specific value, the BA frame may include information that the BA frame is an EHT multi-band/link BA frame. For example, if the BA type included in the BA frame has a value of 15, it may mean that the BA frame is a BA frame including ACK information for multi-band/link.
The BA Information field may include information on a fragment number and a sequence number of data for which a response related to whether it is received or not per traffic identifier (TID). For example, the fragment number and the sequence number may be included in the Block Ack Starting Sequence Control field. ACK (i.e., whether it is received or not) information of data for which a response related to whether it is received is requested may be included in the BlockAck Bitmap field. When ACK information needs to be transmitted for one or more TIDs, the Per TID info field may include information on TIDs of data. The BlockAck number field may include information on which fragment and/or sequence the ACK is.
For example, when the receiving STA receives a request for ACKs for all fragments of the same sequence, the BA Information field may include information on a sequence number and may include a Concatenated BlockAck Bitmap field. For example, the Concatenated BlockAck Bitmap field may include a BlockAck Bitmap field for a plurality of fragments. Information that the BA frame includes ACK information for a plurality of bands/links may be transmitted based on a new field or a new value, or may be included in other unused fields (for example, a reserved field, etc.). That is, the position of the field including information indicating that the BA frame includes ACK information for a plurality of bands/links is not limited.
The transmitting STA and the receiving STA may negotiate on a method for an ACK response. Negotiation may be performed through an action frame, or may be performed through an arbitrary field included in each data frame. Alternatively, negotiation on the method for the ACK response may be performed using an existing field included in the data frame.
Some of the steps described above may not be essential. Accordingly, some steps may be omitted. In addition, since the order of the above-described steps is an example, the order of performing each step may vary. Also, only one of the above-described steps may have an independent technical meaning. The Ack frame in the above-described embodiment may be expressed through bitmap extension of the previously used Block ACK frame, or a new ACK frame format may be used. That is, the transmission method of the ACK frame (i.e., the BA frame) is not limited.
Some of the detailed steps shown in the example of
The technical features of the present specification described above may be applied to various devices and methods. For example, the above-described technical features of the present specification may be performed/supported through the apparatus of
The technical features of the present specification may be implemented based on a computer readable medium (CRM). For example, the CRM proposed by the present specification includes at least an instruction, based on being executed by at least one processor of a station (STA) in a wireless local area network (WLAN) system, to perform operations, the operations comprise, receiving, from a transmitting STA, a first signal through a first link and a second signal through a second link, and transmitting, to the transmitting STA through the second link, a response signal related to whether the first and second signals are received, wherein the response signal includes a first field related to that the response signal includes a response to whether a plurality of signals transmitted through a plurality of links are received.
The instructions stored in the CRM of the present specification may be executed by at least one processor. At least one processor related to CRM in the present specification may be the processors 111 and 121 or the processing chips 114 and 124 of
The foregoing technical features of the present specification are applicable to various applications or business models. For example, the foregoing technical features may be applied for wireless communication of a device supporting artificial intelligence (AI).
Artificial intelligence refers to a field of study on artificial intelligence or methodologies for creating artificial intelligence, and machine learning refers to a field of study on methodologies for defining and solving various issues in the area of artificial intelligence. Machine learning is also defined as an algorithm for improving the performance of an operation through steady experiences of the operation.
An artificial neural network (ANN) is a model used in machine learning and may refer to an overall problem-solving model that includes artificial neurons (nodes) forming a network by combining synapses. The artificial neural network may be defined by a pattern of connection between neurons of different layers, a learning process of updating a model parameter, and an activation function generating an output value.
The artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer includes one or more neurons, and the artificial neural network may include synapses that connect neurons. In the artificial neural network, each neuron may output a function value of an activation function of input signals input through a synapse, weights, and deviations.
A model parameter refers to a parameter determined through learning and includes a weight of synapse connection and a deviation of a neuron. A hyper-parameter refers to a parameter to be set before learning in a machine learning algorithm and includes a learning rate, the number of iterations, a mini-batch size, and an initialization function.
Learning an artificial neural network may be intended to determine a model parameter for minimizing a loss function. The loss function may be used as an index for determining an optimal model parameter in a process of learning the artificial neural network.
Machine learning may be classified into supervised learning, unsupervised learning, and reinforcement learning.
Supervised learning refers to a method of training an artificial neural network with a label given for training data, wherein the label may indicate a correct answer (or result value) that the artificial neural network needs to infer when the training data is input to the artificial neural network. Unsupervised learning may refer to a method of training an artificial neural network without a label given for training data. Reinforcement learning may refer to a training method for training an agent defined in an environment to choose an action or a sequence of actions to maximize a cumulative reward in each state.
Machine learning implemented with a deep neural network (DNN) including a plurality of hidden layers among artificial neural networks is referred to as deep learning, and deep learning is part of machine learning. Hereinafter, machine learning is construed as including deep learning.
The foregoing technical features may be applied to wireless communication of a robot.
Robots may refer to machinery that automatically process or operate a given task with own ability thereof. In particular, a robot having a function of recognizing an environment and autonomously making a judgment to perform an operation may be referred to as an intelligent robot.
Robots may be classified into industrial, medical, household, military robots and the like according uses or fields. A robot may include an actuator or a driver including a motor to perform various physical operations, such as moving a robot joint. In addition, a movable robot may include a wheel, a brake, a propeller, and the like in a driver to run on the ground or fly in the air through the driver.
The foregoing technical features may be applied to a device supporting extended reality.
Extended reality collectively refers to virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology is a computer graphic technology of providing a real-world object and background only in a CG image, AR technology is a computer graphic technology of providing a virtual CG image on a real object image, and MR technology is a computer graphic technology of providing virtual objects mixed and combined with the real world.
MR technology is similar to AR technology in that a real object and a virtual object are displayed together. However, a virtual object is used as a supplement to a real object in AR technology, whereas a virtual object and a real object are used as equal statuses in MR technology.
XR technology may be applied to a head-mount display (HMD), a head-up display (HUD), a mobile phone, a tablet PC, a laptop computer, a desktop computer, a TV, digital signage, and the like. A device to which XR technology is applied may be referred to as an XR device.
The claims recited in the present specification may be combined in a variety of ways. For example, the technical features of the method claim of the present specification may be combined to be implemented as a device, and the technical features of the device claims of the present specification may be combined to be implemented by a method. In addition, the technical characteristics of the method claim of the present specification and the technical characteristics of the device claim may be combined to be implemented as a device, and the technical characteristics of the method claim of the present specification and the technical characteristics of the device claim may be combined to be implemented by a method.
Filing Document | Filing Date | Country | Kind |
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PCT/KR2020/006618 | 5/21/2020 | WO |
Number | Date | Country | |
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62854313 | May 2019 | US | |
62863244 | Jun 2019 | US |