Access point and communication method

Abstract

This access point comprises: a control circuit that generates a control signal for allocating at least a portion of time of an acquired transmission opportunity to uplink transmissions of a plurality of terminals; and a transmission circuit that transmits the control signal.

Description

Technical Field

[0001] The present disclosure relates to an access point, a terminal, and a communication method.

Background Art

[0002] In the Institute of Electrical and Electronics Engineers (IEEE), the standard IEEE 802.11be (hereinafter also referred to as "11be") for a next-generation wireless local area network (LAN), which is a successor standard to the standard IEEE 802.11ax (hereinafter also referred to as "11ax"), is being studied. For example, IEEE 802.11ax is also called High Efficiency (HE), and IEEE 802.11be is also called Extreme High Throughput (EHT).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Non-Patent Document 5

[0004] However, the method for allocating transmission opportunities in wireless communication such as Wi-Fi has not been sufficiently considered.

[0005] Non-limiting embodiments of this disclosure contribute to providing access points, terminals, and communication methods that can improve the efficiency of assigning transmission opportunities in wireless communication.

[0006] An access point according to one embodiment of the present disclosure comprises a control circuit that generates an uplink control signal, which includes information regarding the allocation of at least a portion of the access point's transmission opportunities to a plurality of terminals different from the access point, and a transmission circuit that transmits the control signal.

[0007] These comprehensive or specific embodiments may be implemented as systems, devices, methods, integrated circuits, computer programs, or recording media, or as any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

[0008] According to one embodiment of this disclosure, for example, the efficiency of assigning transmission opportunities in wireless communication can be improved.

[0009] Further advantages and effects of one embodiment of this disclosure will be made apparent from the specification and drawings. Such advantages and / or effects are provided by several embodiments and features described in the specification and drawings, but not all of them are necessarily provided in order to obtain one or more identical features. [Brief explanation of the drawing]

[0010] [Figure 1]A diagram showing an example of a trigger frame. [Figure 2] A diagram showing an example of a Common Info field. [Figure 3] A diagram showing an example of a User Info field. [Figure 4] A diagram showing an example of a Special User Info field. [Figure 5] A diagram showing an example of TXOP Sharing mode. [Figure 6] Sequence diagram showing an example of TXOP Sharing mode 1 operation. [Figure 7] Sequence diagram showing an example of TXOP Sharing mode 1 operation. [Figure 8] Sequence diagram showing an example of TXOP Sharing operation for multiple stations (STA) using Frequency Division Multiplexing (FDM). [Figure 9] Sequence diagram showing an example of TXOP Sharing operation for multiple stations (STA) using Frequency Division Multiplexing (FDM). [Figure 10] Block diagram showing some configuration examples of access points (APs). [Figure 11] Block diagram showing some configuration examples of STA [Figure 12] Block diagram showing an example of AP configuration. [Figure 13] A diagram showing an example of the TXOP Sharing mode according to Embodiment 1. [Figure 14] Block diagram showing an example configuration of an STA terminal. [Figure 15] A diagram showing an example of a User Info field according to Embodiment 1. [Figure 16] A diagram illustrating an example of a method for notifying about frequency resources. [Figure 17] A diagram illustrating an example of a method for notifying about frequency resources. [Figure 18]Figure showing an example of a method for notifying frequency resources [Figure 19] Sequence diagram showing an operation example of TXOP Sharing for a plurality of STAs by FDM according to Embodiment 1 [Figure 20] Sequence diagram showing an operation example of TXOP Sharing for a plurality of STAs by FDM according to Embodiment 1 [Figure 21] Sequence diagram showing an operation example of TXOP Sharing for a plurality of STAs by time division multiplexing (TDM) [Figure 22] Sequence diagram showing an operation example of TXOP Sharing for a plurality of STAs by TDM according to Embodiment 2 [Figure 23] Sequence diagram showing an operation example of TXOP Sharing for a plurality of STAs by TDM according to Embodiment 2 [Figure 24] Figure showing an example of the User Info field according to Embodiment 2 [Figure 25] Sequence diagram showing an operation example of TXOP Sharing for a plurality of STAs by TDM according to Embodiment 2 [Figure 26] Figure showing an example of the Common Info field [Figure 27] Figure showing an example of the TXOP Sharing mode for multi - user

Embodiments for Carrying Out the Invention

[0011] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings.

[0012] <神仙道 In 11be, as with 11ax, a priority control scheme called Enhanced Distributed Channel Access (EDCA) may be used to prioritize individual transmission opportunities for Access Categories (ACs). In EDCA, for example, an AC that has acquired transmission rights is allowed to continuously transmit radio signals at intervals of Short Inter Frame Space (SIFS). This period during which continuous transmission is possible may be called "Transmission Opportunity (TXOP)". The upper limit of the TXOP time may be defined individually for each AC, for example.

[0013] In 11be, for example, "TXOP sharing" is considered, which allocates at least a portion of the TXOPs acquired by an access point (AP, also called a "base station") to a terminal (STA, also called a "non-AP STA"). For example, a procedure in which an AP triggers TXOP sharing for a single STA (e.g., "Triggered TXOP sharing procedure") is considered (see, for example, Non-Patent Documents 1-5).

[0014] In 11ax, for example, an AP (Access Point) uses a control signal that instructs the transmission of an uplink signal (hereinafter referred to as a "trigger frame") to schedule the uplink radio resources of the STA (for example, referred to as "Triggered UL operation"). Triggered UL operation improves the efficiency of orthogonal multiplexing for the uplink signal of the STA, thereby improving throughput performance.

[0015] In a Triggered UL operation, for example, the AP dynamically monitors the status of each STA, such as its transmit buffer status (e.g., BSR: Buffer Status Report) or communication quality, and calculates several radio parameters to apply to each STA's uplink signal (e.g., the uplink response signal to the trigger frame) based on the STA's status. These radio parameters include, for example, signal length, Modulation and Coding Scheme (MCS), number of spatial streams, and transmit power for the uplink signal. Thus, in a Triggered UL operation, the processing (e.g., calculations) involved in AP scheduling can become complex.

[0016] The uplink response signal is sometimes referred to as, for example, a trigger-based physical layer protocol data unit (TB PPDU).

[0017] On the other hand, in TXOP sharing, for example, if an AP allocates a portion of its acquired TXOP to a STA, a transmission blackout period (NAV: Network Allocation Vector) may be set for STAs other than the STA to which the portion of the TXOP was allocated. By setting the NAV, collisions of transmission signals from STAs to which the portion of the TXOP was allocated can be suppressed. In addition, STAs to which TXOP sharing is applied can improve signal transmission efficiency by determining the radio parameters applied to their transmission signals based on the STA's transmission buffer state or communication quality. In other words, in TXOP sharing, the AP does not need to perform at least part of the scheduling for the uplink signals transmitted by the STA, thus simplifying the AP's processing compared to Triggered UL operation.

[0018] Thus, in 11be, for example, support for Triggered UL operation and TXOP sharing can suppress collisions in the STA's uplink signal and improve throughput performance through simplified processing at the AP.

[0019] In 11be, for example, it is being considered that an AP can instruct a single STA to perform TXOP sharing using a Trigger frame (hereinafter referred to as a "MU-RTS Trigger frame") with the type of Trigger frame (for example, called "Trigger Type") set to Multi-User Request-To-Send (MU-RTS) (see, for example, Non-Patent Document 1).

[0020] Figure 1 shows an example of a trigger frame. As shown in Figure 1, the trigger frame includes a field containing information common to multiple STAs (e.g., a "common information field") and a field called a User Info List for multiple STAs that are frequency multiplexed. The User Info List may include one or more fields containing information specific to each STA (e.g., "user information fields").

[0021] Furthermore, in 11be, for example, the Trigger frame may include a field (e.g., "Special User Info field") that contains information for STAs corresponding to 11be (EHT) (not shown).

[0022] Figure 2 shows an example of the configuration of a Common Info field (e.g., an EHT variant of the Common Info field format) considered in 11be (e.g., EHT). Figure 3 shows an example of the configuration of a User Info field (e.g., an EHT variant of the User Info field format) considered in 11be (EHT) (see, for example, Non-Patent Document 1). Figure 4 shows an example of the configuration of a Special User Info field (see, for example, Non-Patent Document 3).

[0023] For example, the Trigger Type subfield in the Common Info field shown in Figure 2 is a subfield that indicates the type of trigger frame (for example, the type of signal that the AP will send to the STA). For example, by setting the Trigger Type to a value that indicates MU-RTS (for example, in the case of 11be, Trigger Type subfield value = 3), the AP can instruct a designated STA to send a MU-RTS trigger frame. For example, if the STA receives a MU-RTS trigger frame and the User Info field contained in the received MU-RTS trigger frame specifies the Association ID (AID) of the STA, the STA may send a Clear To Send (CTS) frame to the AP.

[0024] In 11be, for example, in the case of a MU-RTS Trigger frame, the area B20-B21 in the Common Info field shown in Figure 2 is recognized as the "TXOP Sharing Mode" subfield related to the TXOP sharing settings.

[0025] In the case of a trigger frame of a different type than the MU-RTS trigger frame, the area B20-21 in the Common Info field may be recognized as the "GI And EHT-LTF Type" subfield. The GI And EHT-LTF Type subfield may contain, for example, parameter information related to the EHT-Long Training Field (LTF). For example, the information contained in the GI And EHT-LTF Type subfield is not used for transmitting CTS frames that do not contain EHT-LTF.

[0026] Figure 5 shows an example of a TXOP Sharing Mode considered in 11be (see, for example, Non-Patent Document 1).

[0027] In Figure 5, when the TxOP Sharing Mode is 0 (TxOP Sharing Mode subfield value=0), TXOP sharing (e.g., MU-RTS TXOP Sharing) is not performed, and the STA sends, for example, a CTS frame to the AP.

[0028] Furthermore, in Figure 5, if the TxOP Sharing Mode is 1 or 2 (TxOP Sharing Mode subfield value = 1 or 2), TXOP sharing (e.g., MU-RTS TXOP Sharing) may be performed.

[0029] For example, when the TxOP Sharing Mode is 1, as shown in Figure 6, during the allocated period (Time allocated in MU-RTS TX TF) corresponding to a portion of the TXOP, the scheduled STA (e.g., Non-AP STA 1 or STA 1) can transmit wireless frames (e.g., Single User (SU) PPDU) to the connected AP (e.g., associated AP). In other words, when the TxOP Sharing Mode is 1, STA 1 does not transmit wireless frames to APs or STAs other than the connected AP.

[0030] Furthermore, for example, when the TxOP Sharing Mode is 2, as shown in Figure 7, during the allocation period (Time allocated in MU-RTS TX TF) which corresponds to a portion of the TXOP, the scheduled STA (e.g., STA 1) can transmit wireless frames to the connected AP or another STA (e.g., STA 2).

[0031] When the TxOP Sharing Mode mentioned above is 1 or greater (or non-zero), that is, when TXOP sharing is applied to a MU-RTS Trigger frame, it is sometimes referred to as a "MU-RTS TXS (TXOP) Trigger frame (MU-RTS TXS TF)".

[0032] Here, as shown in Figures 6 and 7, if the AP receives a CTS frame (e.g., CTS response) from the scheduled STA in response to the MU-RTS TXS Trigger frame, it may determine that TXOP sharing has been appropriately instructed to the STA. In this case, the AP does not need to transmit a signal different from the ACK response (e.g., Black Ack) requested by the scheduled STA during the allocation period. For example, as shown in Figures 6 and 7, if the carrier sense is idle between Point Coordination Function (PCF) Interframe Spaces (PIFS) during the allocation period, the AP may reclaim the TXOP from the STA and transmit a signal to another STA.

[0033] For example, in 11be, only one STA can be instructed using the MU-RTS Trigger frame, and one User Info field, as shown in Figure 3, is set in the MU-RTS Trigger frame (see, for example, Non-Patent Document 1). Also, during the allocation period for an STA in TXOP Sharing, the STA may determine parameters such as the MCS of the transmitted signal and transmit an SU PPDU of a specified bandwidth (e.g., 20 MHz × N (where N is an integer) bandwidth). Furthermore, the use of a subfield of the Common Info field (e.g., the UL Length subfield) may be considered for instructing the allocation period for an STA.

[0034] Here, for example, the method by which an AP instructs multiple STAs to perform TXOP sharing (e.g., trigger frame format or procedure) has not been sufficiently considered.

[0035] In non-limiting embodiments of this disclosure, an example of how an AP instructs multiple STAs to perform TXOP sharing is described.

[0036] (Embodiment 1) This embodiment describes a case where TXOP sharing to multiple STAs is performed using FDM (Frequency Multiplexing).

[0037] Figure 8 shows an example sequence in which the AP performs FDM-based TXOP sharing for STA 1 and STA 2 when TxOP Sharing Mode=1 (for example, when a scheduled STA communicates with the connected AP).

[0038] In Figure 8, the AP may, for example, use a MU-RTS TXS Trigger frame to allocate orthogonal frequency resources (e.g., 20MHz channel × N (channels in units of 20MHz)) to STA 1 and STA 2, respectively.

[0039] Here, STA 1 and STA 2 may each determine the duration of the SU PPDU. As a result, as shown in Figure 8, the duration of the SU PPDU may differ between STA 1 and STA 2, which may cause the timing of AP transmission and reception (for example, sending an ACK to STA 2 and receiving a PPDU from STA 1) to overlap. For example, if an AP that does not support full-duplex communication overlaps with the transmission and reception timings, it may not process either the transmitted or received signal. Furthermore, even if the AP supports full-duplex communication, reception performance may deteriorate due to, for example, self-interference (when the received signal contains interference from adjacent channels of the transmitted signal).

[0040] Figure 9 shows an example sequence in which the AP performs FDM-based TXOP sharing for STA 1 and STA 2 when TxOP Sharing Mode=2 (for example, in the case of inter-STA communication where a scheduled STA communicates with another STA).

[0041] Note that STA-to-STA communication is also called peer-to-peer (P2P) or Direct Link (DiL).

[0042] In Figure 9, similar to Figure 8, the AP may allocate orthogonal frequency resources (e.g., 20MHz channel × N) to STA 1 and STA 2, respectively, using, for example, a MU-RTS TXS Trigger frame. Here, since the P2P communication between STA 1 and STA 3 and the P2P communication between STA 2 and STA 4 are performed in an FDM-decoded bandwidth, even if the SU PPDU time lengths differ between STA 1 and STA 2, there is no overlap in the transmission and reception timing at the AP as described in Figure 8.

[0043] This embodiment describes, for example, a method for suppressing overlapping transmission and reception timings at the AP and for performing TXOP sharing to multiple STAs using FDM.

[0044] [Configuration of the wireless communication system] The wireless communication system according to this embodiment may include, for example, an AP100 shown in Figure 10 and an STA200 shown in Figure 11. At least one of the AP100 and STA200 may be present in two or more instances in the wireless communication system. The AP100 may, for example, transmit a trigger frame (e.g., a MU-RTS TXS trigger frame) to the STA200 instructing TXOP Sharing. The STA200 receives the MU-RTS TXS trigger frame and may transmit a signal to the AP100 or another STA based on the resources (e.g., allocation period) indicated by the received MU-RTS TXS trigger frame.

[0045] Figure 10 is a block diagram showing a partial configuration example of AP100 according to one embodiment of the present disclosure. In the AP100 shown in Figure 10, the control unit (e.g., corresponding to a control circuit) generates a control signal (e.g., a trigger frame) to allocate at least a portion of the time (e.g., an allocation period) of the acquired transmission opportunity (e.g., TXOP) to the uplink transmission of multiple STA200s. The transmission unit (e.g., corresponding to a transmission circuit) transmits the control signal.

[0046] Figure 11 is a block diagram showing a partial configuration example of an STA200 according to one embodiment of the present disclosure. In the STA200 shown in Figure 11, the receiving unit (e.g., corresponding to a receiving circuit) receives a control signal (e.g., a trigger frame) for allocating at least a portion of the transmission opportunity (e.g., TXOP) acquired by AP100 to uplink transmissions of multiple STAs. The control unit (e.g., corresponding to a control circuit) controls uplink transmissions for at least a portion of the transmission opportunities based on the control signal.

[0047] [Example configuration of AP100] AP100 generates a trigger frame (e.g., a MU-RTS TXS trigger frame) that instructs TXOP sharing to multiple STAs, and sends the MU-RTS TXS trigger frame to STA200.

[0048] Figure 12 is a block diagram showing an example configuration of AP100. The AP100 shown in Figure 12 may include, for example, a scheduling unit 101, a TXOP sharing mode setting unit 102, a Common Info generation unit 103, a User Info generation unit 104, a Trigger frame generation unit 105, an error correction coding unit 106, a modulation unit 107, a wireless transmission / reception unit 108, a demodulation unit 109, an error correction decoding unit 110, and an STA information acquisition unit 111.

[0049] For example, the scheduling unit 101, the TXOP sharing mode setting unit 102, the Common Info generation unit 103, the User Info generation unit 104, the Trigger frame generation unit 105, and the STA information acquisition unit 111 may be included in the access control unit (for example, the Medium Access Control (MAC) processing unit).

[0050] Furthermore, at least one of the scheduling unit 101, TXOP sharing mode setting unit 102, Common Info generation unit 103, User Info generation unit 104, Trigger frame generation unit 105, error correction coding unit 106, modulation unit 107, demodulation unit 109, error correction decoding unit 110, and STA information acquisition unit 111 shown in Figure 12 may be included in the control unit shown in Figure 10, for example. Also, the wireless transmission / reception unit 108 shown in Figure 12 may be included in the transmission unit shown in Figure 10, for example.

[0051] The scheduling unit 101 may, for example, perform scheduling for the STA200. For example, the scheduling unit 101 may determine the TXOP Sharing mode to apply to the STA200 and the allocated radio resources (for example, including at least one of the allocation period and bandwidth in TXOP sharing) based on the STA information input from the STA information acquisition unit 111.

[0052] For example, the TXOP Sharing mode may include not only the TXOP Sharing mode for one STA as described above, but also a TXOP Sharing mode for multiple STAs. When applying the TXOP Sharing mode to multiple STAs, the scheduling unit 101 may determine, for example, whether the communication during the allocation period for the multiple STA200s to which TXOP sharing is applied is destined for AP100 (e.g., communication between AP100 and STA200) or destined for another STA (e.g., P2P communication (inter-terminal communication)).

[0053] Furthermore, multiple TXOP sharing modes may be defined for multiple STAs. For example, during the allocated period to which TXOP sharing is applied, a mode may be defined in which the signals of multiple STAs are frequency multiplexed (FDM), and a mode may be defined in which the signals of multiple STAs are time multiplexed (TDM). Note that the multiplexing method for signals of multiple STAs is not limited to FDM and TDM, but may also be other multiplexing methods.

[0054] Furthermore, the allocated radio resources may include, for example, a portion of the duration of the TXOP acquired by AP100 (e.g., time resources). Also, for example, if TXOP sharing to multiple STAs is applied by FDM, the allocated radio resources may include the channels allocated to each STA200 (e.g., bandwidth in units of 20 MHz).

[0055] Furthermore, the STA information may include, for example, STA200 capability information, transmit buffer status, and control information related to P2P settings.

[0056] Furthermore, the capability information may include, for example, information indicating whether the STA200 is capable of transmitting and receiving on a channel different from the primary channel.

[0057] Furthermore, the transmit buffer status may include, for example, information regarding the AC and size of the transmit buffer destined for AP100 in STA200. The transmit buffer status may also include, for example, information regarding the AC and size of the transmit buffer destined for another STA (for example, also called a "Direct Link Peer (DLP) STA") connected to STA200 via a P2P link (or Direct Link).

[0058] Furthermore, the P2P configuration information may include, for example, the STA ID (STA-specific ID) of the STA that will communicate with the STA200 via P2P.

[0059] The scheduling unit 101 outputs information regarding the determined TXOP sharing mode and allocated wireless resources for each STA200 to the Common Info generation unit 103 and the User Info generation unit 104, for example.

[0060] The TXOP sharing mode setting unit 102 may, for example, set an association between a TXOP sharing mode and information indicating the TXOP sharing mode in the trigger frame (for example, a TXOP sharing mode value), and may store information regarding the set TXOP sharing mode. The TXOP sharing mode setting unit 102 may output the stored information regarding the TXOP sharing mode to the Common Info generation unit 103.

[0061] The association between the TXOP sharing mode and the information indicating the TXOP sharing mode in the trigger frame may be in the form of information in a table format (for example, called the "TXOP sharing mode table") or in a format other than a table. Figure 13 shows an example of a TXOP sharing mode table held by the TXOP sharing mode setting unit 102. The TXOP sharing mode table shown in Figure 13 may include, for example, the TXOP sharing mode described in Non-Patent Literature 1 shown in Figure 5 (for example, any of TXOP sharing mode = 0 to 2), and the TXOP sharing mode for multiple STA200s (for example, TXOP sharing mode = 3).

[0062] The Common Info generation unit 103 may, for example, generate control information included in a Common Info field common to multiple STA200s. The Common Info generation unit 103 may, for example, generate information for the TXOP sharing mode subfield based on the "type of TXOP sharing mode" included in the information on TXOP sharing mode input from the scheduling unit 101, and the information on TXOP sharing mode input from the TXOP sharing mode setting unit 102 (for example, the TXOP sharing mode table).

[0063] Furthermore, the Common Info generation unit 103 may generate information regarding the allocation period to the STA200 based, for example, on information regarding the allocated wireless resources input from the scheduling unit 101.

[0064] For example, when performing TXOP sharing, the Common Info generation unit 103 may generate a MU-RTS TXS Trigger frame by setting the Trigger type subfield to MU-RTS and the TXOP sharing mode subfield to a predetermined value (for example, any value of 1 or more in the case of the TXOP sharing mode table in Figure 13).

[0065] The Common Info generation unit 103 may output information about the generated Common Info field to the Trigger frame generation unit 105.

[0066] Note that the term "settings" in fields (e.g., subfields) within a trigger frame may be replaced with other terms such as "definition" or "interpretation."

[0067] The User Info generation unit 104 may, for example, generate control information contained in individual User Info fields in the Special User Info field or STA200. The User Info generation unit 104 may, for example, generate information about individual User Info fields in the Special User Info field or STA200 based on a defined format, and generate information about a User Info List containing User Info fields for each of the multiple STA200s. The User Info generation unit 104 may, for example, output information about the User Info List to the Trigger frame generation unit 105.

[0068] The individual User Info fields in STA200 may include, for example, information indicating whether the communication during the allocation period is destined for AP100 or for another STA (for example, referred to as "communication type information"), and information regarding the allocated channel (bandwidth in 20MHz units), which are included in the TXOP sharing mode information input from the scheduling unit 101. Note that the communication type information may be notified to STA200, for example, when TXOP sharing mode is applied to multiple STAs. In other words, when TXOP Sharing mode is applied to a single STA, the communication type information does not need to be notified to STA200.

[0069] Furthermore, the number of User Info fields included in the User Info List may be associated with the TXOP sharing mode indicated in the TXOP sharing mode subfield, for example. For instance, if the TXOP sharing mode is a mode that applies TXOP sharing to one STA (for example, if TXOP sharing mode = 1, 2 is indicated in the TXOP sharing mode table shown in Figure 13), the User Info List may contain one User Info field. On the other hand, if the TXOP sharing mode is a mode that applies TXOP sharing to multiple STAs (for example, if TXOP sharing mode = 3 is indicated in the TXOP sharing mode table shown in Figure 13), the User Info List may contain multiple User Info fields.

[0070] Furthermore, the Special User Info field may contain control information for a single STA200, regardless of the TXOP sharing mode.

[0071] The Trigger frame generation unit 105 may generate a Trigger frame that includes information from the Common Info field input from the Common Info generation unit 103 and information from the User Info List (e.g., the Special User Info field and at least one User Info field) input from the User Info generation unit 104, based on the format shown in Figure 1. The Trigger frame may include, for example, at least one of the following: the Common Info field and the User Info List, as well as the MAC header, Padding, and Frame Check Sequence (FCS). The Trigger frame generation unit 105 may output the generated Trigger frame to the Error Correction Encoding Unit 106.

[0072] The error correction coding unit 106, for example, errors-corrects and encodes the transmission data signal, which includes the trigger frame input from the trigger frame generation unit 105, and outputs the encoded signal to the modulation unit 107.

[0073] The modulation unit 107 performs modulation processing on the signal input from the error correction coding unit 106, for example, and outputs the modulated signal to the wireless transceiver unit 108.

[0074] Furthermore, if the modulated data signal is an orthogonal frequency division multiplexing (OFDM) signal, AP100 (for example, the modulation unit 107) may map the modulated signal to a specified frequency resource, perform an inverse fast Fourier transform (IFFT) to convert it into a time waveform, and add a cyclic prefix (CP) to form an OFDM signal.

[0075] The wireless transceiver 108 performs wireless transmission processing on the modulated signal input from the modulation unit 107, such as D / A conversion and upconversion to the carrier frequency, and transmits the processed signal to the STA200 via the antenna. The wireless transceiver 108 also receives the signal transmitted from the STA200 via the antenna, performs wireless reception processing on the received signal, such as downconversion to the baseband and A / D conversion, and outputs the processed signal to the demodulation unit 109.

[0076] The demodulation unit 109 performs demodulation processing on the signal input from the wireless transceiver unit 108, for example, and outputs the demodulated signal to the error correction decoding unit 110. If the signal input to the demodulation unit 109 is an OFDM signal, the AP100 (for example, the demodulation unit 109) may perform CP removal processing and Fast Fourier Transform (FFT) processing.

[0077] The error correction decoding unit 110 decodes the signal input from the demodulation unit 109, for example, to obtain the received data signal from the STA 200. If the decoded received data contains the STA information described above, the error correction decoding unit 110 outputs the decoded data containing the STA information to the STA information acquisition unit 111.

[0078] The STA information acquisition unit 111 may, for example, acquire STA information (which may include, for example, STA200 capability information, transmission buffer status, or P2P setting information) from the decoded data input from the error correction decoding unit 110, and output the acquired STA information to the scheduling unit 101.

[0079] [STA200 Configuration Example] For example, STA200 receives a trigger frame (e.g., a MU-RTS TXS trigger frame) from AP100 that instructs TXOP sharing, and sends an uplink response signal (e.g., a CTS frame) or an SU PPDU containing the transmission data to AP100. Then, based on the instructions of the MU-RTS TXS trigger frame, STA200 communicates with AP100 or another STA using the assigned channel within the assigned period.

[0080] Figure 14 is a block diagram showing an example configuration of the STA200. The STA200 shown in Figure 14 may include, for example, a wireless transceiver unit 201, a demodulation unit 202, an error correction decoding unit 203, a TXOP sharing mode setting unit 204, a Common Info acquisition unit 205, a User Info acquisition unit 206, a TXOP sharing control unit 207, a data generation unit 208, an error correction coding unit 209, and a modulation unit 210.

[0081] For example, at least one of the TXOP sharing mode setting unit 204, the Common Info acquisition unit 205, the User Info acquisition unit 206, the TXOP sharing control unit 207, and the data generation unit 208 may be included in the access control unit (e.g., the MAC processing unit).

[0082] Furthermore, at least one of the demodulation unit 202, error correction decoding unit 203, TXOP sharing mode setting unit 204, Common Info acquisition unit 205, User Info acquisition unit 206, TXOP sharing control unit 207, data generation unit 208, error correction coding unit 209, and modulation unit 210 shown in Figure 14 may be included in the control unit shown in Figure 11, for example. Also, the wireless transmission / reception unit 201 shown in Figure 14 may be included in the receiving unit shown in Figure 11, for example.

[0083] The wireless transceiver unit 201, for example, receives a received signal via an antenna, performs wireless reception processing on the received signal such as down-conversion and A / D conversion, and outputs the processed signal to the demodulation unit 202. The wireless transceiver unit 201 also performs wireless transmission processing on the signal input from the modulation unit 210, for example, performs up-conversion and D / A conversion, and transmits the processed signal from the antenna.

[0084] The demodulation unit 202 performs demodulation processing on the received data input from the wireless transceiver unit 201, for example, and outputs the demodulated signal to the error correction decoding unit 203. If the signal input to the demodulation unit 202 is an OFDM signal, the STA200 (for example, the demodulation unit 202) may perform, for example, CP removal processing and FFT processing.

[0085] The error correction decoding unit 203 may, for example, decode the demodulated signal input from the demodulation unit 202 and output the decoded signal as the received data signal. The error correction decoding unit 203 may also, for example, output the trigger frame from the received data signal to the Common Info acquisition unit 205 and the User Info acquisition unit 206.

[0086] The TXOP sharing mode setting unit 204 may perform operations similar to those of the TXOP sharing mode setting unit 102 of AP100, for example. For example, the TXOP sharing mode setting unit 204 may output information regarding a predefined TXOP sharing mode (e.g., a TXOP sharing mode table) to the Common Info acquisition unit 205.

[0087] The Common Info acquisition unit 205 may, for example, if the Trigger type of the Trigger frame input from the error correction decoding unit 203 is MU-RTS, extract information corresponding to the Common Info field from the Trigger frame input from the error correction decoding unit 203 based on information input from the TXOP sharing mode setting unit 204 (for example, the TXOP sharing mode table), and acquire STA common information regarding TXOP sharing.

[0088] Common STA information regarding TXOP sharing may include, for example, information about the TXOP sharing mode and information about the allocation period to STA200. Note that information about the allocation period to STA200 may also be included as STA-specific information in the User Info field. Furthermore, common STA information may include, for example, information indicating that it is an FDM-based TXOP sharing mode for multiple STAs.

[0089] The Common Info acquisition unit 205 may output the extracted STA common information to the User Info acquisition unit 206.

[0090] The User Info Acquisition Unit 206 may, for example, extract information corresponding to the User Info List (e.g., at least one User Info field and a Special User Info field) from the Trigger frame input from the Error Correction Decoding Unit 203, and perform reception processing of the User Info field based on the STA common information (e.g., including the TXOP sharing mode) input from the Common Info Acquisition Unit 205. The User Info Acquisition Unit 206 may, for example, perform reception processing of multiple User Info fields if the TXOP sharing mode instructs TXOP sharing to multiple STAs. Alternatively, the User Info Acquisition Unit 206 may, for example, perform reception processing of one User Info field if the TXOP sharing mode instructs TXOP sharing to one STA.

[0091] For example, the User Info acquisition unit 206 decodes the information identifying the STA200 contained in the User Info field (e.g., STA ID or AID), and if it determines that there is an allocation instruction addressed to the STA200, it may acquire at least one of the following from the User Info field: STA-specific information regarding TXOP sharing, and STA-common information (including, for example, "information on the allocation period to the STA," "information indicating whether the communication during the allocation period is addressed to an AP or another STA," and "information on the allocated channel (bandwidth in 20MHz units)"). Note that the information indicating whether the communication during the allocation period is addressed to an AP or another STA is included in the User Info field when applying TXOP sharing mode to multiple STAs, but does not need to be included when applying TXOP sharing mode to a single STA.

[0092] The User Info acquisition unit 206 may output, for example, STA individual information and STA common information to the TXOP sharing control unit 207 and the data generation unit 208.

[0093] The TXOP sharing control unit 207 may determine the allocated radio resource based on information input from the User Info acquisition unit 206 (for example, including STA individual information and STA common information). The TXOP sharing control unit 207 may control data transmission on the TXOP-shared radio resource instructed by the AP 100 based on the allocated radio resource. Control of data transmission may include, for example, control of the allocation period, the allocated channel, and the destination of communication within the allocation period. For example, in the case of FDM-based TXOP sharing mode to multiple STAs, the TXOP sharing control unit 207 may determine the frequency resource position of the transmission signal based on instruction information from the AP 100 included in the User Info field. The TXOP sharing control unit 207 may output control information regarding data transmission according to TXOP sharing to the data generation unit 208.

[0094] The data generation unit 208 generates a data signal (for example, a CTS frame, data addressed to AP100, or data addressed to another STA) based on control information input from the TXOP sharing control unit 207 and information input from the User Info acquisition unit 206, and outputs the data signal to the error correction encoding unit 209.

[0095] For example, the data generation unit 208 may generate a CTS frame after being instructed to perform TXOP sharing. Alternatively, the data generation unit 208 may generate a data signal (e.g., PPDU) after transmitting the CTS frame (e.g., after transmitting the CTS frame and after SIFS).

[0096] Here, some of the radio parameters applied to the data signal (for example, signal length, MCS, number of spatial streams, and at least one of the transmit power) may be determined by STA200 based on parameters such as the transmit buffer state or communication quality of STA200. The data signal length may be, for example, within the allocated period instructed by AP100. The transmit channel assigned to the data signal may also be determined based on the assigned channel instructed by AP100.

[0097] The error correction coding unit 209 performs error correction coding on the data signal input from the data generation unit 208 and outputs the coded signal to the modulation unit 210. The coding rate for the data signal may be determined, for example, by STA200.

[0098] The modulation unit 210 modulates the signal input from the error correction coding unit 209 and outputs the modulated signal to the wireless transceiver unit 201. The modulation scheme applied in the modulation unit 210 may be determined by, for example, the STA 200. Furthermore, if the modulated signal is an OFDM signal, the STA 200 (for example, the modulation unit 210) may form an OFDM signal by mapping the modulated signal to frequency resources, performing IFFT processing, and adding CP.

[0099] [Examples of AP100 and STA200 operation] Next, we will describe examples of the operation of AP100 and STA200 according to this embodiment.

[0100] The following describes how to instruct multiple STA200s (e.g., Non-AP STAs) that are different from AP100 to perform TXOP sharing (e.g., allocating a portion of the transmission opportunities (TXOPs) acquired by AP100) using a single trigger frame (e.g., a MU-RTS TXS trigger frame) generated by AP100 (e.g., a Common Info generation unit 103, a User Info generation unit 104, and a Trigger frame generation unit 105).

[0101] In addition, a plurality of STA200s different from AP100 may include, for example, a pair of STA200s that perform P2P communication (for example, communication between terminals).

[0102] <Example of notification of STA common information> The STA common information may include, for example, information regarding the TXOP sharing mode and information regarding the allocation period of TXOP sharing for the STA200.

[0103] AP100 may generate information (for example, TXOP sharing mode subfield value) of the TXOP sharing mode subfield based on, for example, the TXOP sharing mode table shown in FIG. 13. The TXOP sharing mode table shown in FIG. 13 may include, for example, information (for example, TXOP Sharing Mode subfield value = 3) for instructing TXOP sharing to a plurality of STAs.

[0104] For example, when instructing TXOP sharing to a plurality of STAs different from AP100, AP100 may generate a Trigger frame including information indicating TXOP sharing mode subfield value = 3 in the TXOP sharing mode table shown in FIG. 13. In other words, AP100 may set information regarding TXOP sharing to a plurality of STAs (for example, information instructing sharing of transmission opportunities to a plurality of STAs) in the Common Info field common to the STA200s in the Trigger frame.

[0105] In addition, when setting information regarding TXOP sharing to a plurality of STAs, AP100 may set a plurality of individual User Info fields to a plurality of STA200s to which TXOP sharing is applied in the Trigger frame, for example.

[0106] Further, AP100 may generate information regarding, for example, the allocation period to STA200 (e.g., a part of the TXOP acquired by AP100). AP100 may include the generated information regarding the allocation period in, for example, the UL length subfield within the Common Info field shown in FIG. 2. Note that the information regarding the allocation period is not limited to the UL Length subfield and may be included in other areas.

[0107] Here, for example, in the information regarding the allocation period, the coarser the time granularity of the allocation period, the lower the number of notification bits of the information regarding the allocation period. For example, AP100 may notify STA200 of the information regarding the allocation period in a part of the bit area of the UL length subfield and set the remaining bit area as a Reserved area. By setting the Reserved area, the scalability in future versions can be improved.

[0108] <Example of Notification of STA-Specific Information> The STA-specific information may include, for example, information regarding communication (e.g., the destination of communication) during the allocation period of the TXOP and information regarding the frequency resource (e.g., the allocated channel) used for the communication.

[0109] AP100 may set, for example, for STA200 to which TXOP sharing is applied, information (e.g., communication type information) indicating whether the communication during the allocation period is communication to the AP (communication between AP100 and STA200) or communication to another STA (P2P communication), and include the set information in the User Info field.

[0110] FIG. 15 shows an example of the User Info field. For example, as shown in FIG. 15, AP100 may set a subfield (e.g., "P2P flag" subfield) for instructing the communication type information in the area B25 which is the Reserved area in FIG. 3.

[0111] Furthermore, the name of the subfield indicating information about communications during the allocated period is not limited to the P2P flag; other names are also acceptable. Additionally, the subfield indicating the type of communication information is not limited to the B25 area; it may be set in other areas. Moreover, the types of communications that can be notified in the communication type information are not limited to two; three or more types are permitted.

[0112] Furthermore, for example, if TXOP sharing mode is applied to multiple STAs (for example, if TXOP sharing mode = 3 in Figure 13), the B25 area may be set to the P2P flag subfield, and if TXOP sharing is not applied to multiple STAs, the B25 area may be set to the Reserved area.

[0113] For example, if the P2P flag subfield value is 0, the communication within the allocation period of STA200 indicated by the AID12 subfield shown in Figure 15 may be set to communication with AP100 (in other words, restricted to communication with AP100). Also, for example, if the P2P flag subfield value is 1, the communication within the allocation period of STA200 indicated by the AID12 subfield shown in Figure 15 may be set to P2P communication (in other words, restricted to P2P communication). Note that the association between the value of the P2P flag and the communication within the allocation period (for example, either communication with AP100 or P2P communication) is not limited to the examples above.

[0114] Here, if the P2P flag subfield value = 0 (for example, communication with AP100), the duration of the signal (SU PPDU) that STA200 transmits to AP100 may be based on the instructions in the Common Info field (for example, the instructions in the UL length subfield). In other words, AP100 may set information regarding the duration of the uplink transmission signal for at least a portion of the TXOP (transmission opportunity) in the Common Info field common to all STA200s in the Trigger frame. In this case, the duration of the transmission signals of multiple STA200s communicating with AP100 during the allocation period will be set in common. As a result, even if there are multiple STA200s communicating with AP100 during the allocation period, the reception timing of transmission signals from multiple STA200s at AP100 will be approximately the same, and the transmission timing of ACKs to each STA200 will also be approximately the same, thus suppressing overlap between AP100's transmission timing and reception timing.

[0115] Furthermore, for example, radio parameters that differ from the duration of the STA200's transmission signal (including MCS and the number of spatial streams) may be determined by the STA200.

[0116] Furthermore, AP100 may generate information regarding the frequency resources (e.g., allocated channels (bandwidth in 20MHz units)) that STA200 will use for communication during the allocated period (e.g., CTS frame transmission, communication with AP100, or P2P communication) using the RU allocation subfield in the User Info field shown in Figure 15.

[0117] Information regarding the allocated channel may, for example, indicate the location of the 20MHz × N frequency resource allocated to STA200. For example, as a method of notifying information regarding the allocated channel, the method of notifying frequency resources in CTS frames by MU-RTS used in 11ax may be applied.

[0118] Figure 16 shows an example of how frequency resources are notified using MU-RTS trigger frames.

[0119] In MU-RTS supported in 11ax, for example, the frequency resources for CTS are individually notified to the STA200 by a combination of the "UL BW subfield" included in the Common Info field of the MU-RTS Trigger frame and the "RU Allocation subfield" included in the User Info field of the MU-RTS Trigger frame. For example, as shown in Figure 16, the UL BW subfield specifies the uplink Operation bandwidth (e.g., 20MHz, 40MHz, 80MHz, or 160MHz), and the RU allocation subfield specifies the location of the frequency resources to be allocated for communication during the allocation period. In this embodiment, the channel to be used by the STA200 during the TXOP sharing allocation period may be indicated in a manner similar to that shown in Figure 16.

[0120] Furthermore, in the Operation Band, including the newly supported 320MHz in 11be, when the location of the communication frequency resource during the allocation period is notified, for example, the "UL Bandwidth Extension subfield" included in the Special User Info field shown in Figure 4 may be used. For example, as shown in Figure 17, the frequency resource location may be notified to the STA200 by a combination of the UL BW subfield in the Common Info field and the UL Bandwidth Extension subfield in the Special User Info field.

[0121] The notification method shown in Figure 16 is a method for notifying the location of frequency resources including the Primary 20MHz channel. However, this embodiment is not limited to this method, and for example, as shown in Figure 18, a method for notifying any 20MHz channel × N frequency resources within the Operation band that do not include the Primary 20MHz channel may also be used.

[0122] For example, in 11ax MU-RTS, the frequency resources for CTS include the primary channel, but in this embodiment, STA200 to which TXOP sharing is applied may be permitted to transmit uplink signals (e.g., CTS frames and data) using frequency resources that do not include the primary channel during the allocation period.

[0123] For example, among multiple STA200s (e.g., including STA 1 and STA 2) instructed to TXOP sharing by a single MU-RTS TXS Trigger frame, if the transmit bandwidth of STA 1 is set to Primary 20MHz, the transmit bandwidth of STA 2 may be set to a frequency resource that does not include the primary channel. In this case, STA 2 may, in response to the MU-RTS TXS Trigger frame, transmit the CTS frame and data using the frequency resource that does not include the primary channel. Alternatively, an STA200 that receives a MU-RTS TXS Trigger frame may transmit a CTS frame based on the carrier sense result at the frequency resource for CTS notified by the MU-RTS TXS Trigger frame. For example, if the frequency resource for CTS notified by the MU-RTS TXS Trigger frame does not include the primary channel, STA200 may transmit the CTS frame at the notified frequency resource even if the primary channel is busy.

[0124] Furthermore, the method of notifying the assigned channel is not limited to indicating the location of the 20MHz × N frequency resource allocated to the STA200 as described above; other methods of notifying frequency resources may also be used.

[0125] Figure 19 shows an example of a sequence for instructing multiple STAs to perform TXOP sharing according to this embodiment.

[0126] In Figure 19, for example, AP100 may notify multiple STAs different from AP100 (e.g., STA 1 and STA 2) of information regarding the TXOP sharing mode and information regarding the allocation period to STA200 (e.g., UL Length) as common STA information. For example, in Figure 19, AP100 may instruct STA 1 and STA 2 to perform TXOP sharing to multiple STAs by notifying them of the TXOP sharing mode subfield value=3 shown in Figure 13.

[0127] Furthermore, in Figure 19, for example, AP100 may notify each of the multiple STA200s of STA-specific information, including information regarding communication during the allocation period (e.g., communication with AP100 or P2P communication) (e.g., P2P flag) and information regarding the allocated channel (e.g., RU allocation). For example, in Figure 19, AP100 may use a MU-RTS TXS Trigger frame to notify STA1 of P2P flag subfield value = 0, thereby instructing communication with AP100 during the allocation period, and to notify STA2 of P2P flag subfield value = 1, thereby instructing P2P communication during the allocation period. Also, in Figure 19, AP100 may instruct STA1 and STA2 to communicate on orthogonal frequency resources.

[0128] In Figure 19, for example, STA 1 may transmit a CTS frame (CTS response) and data signal (DATA) destined for AP100 on the channel allocated to STA 1 for the TXOP sharing allocation period, based on the received MU-RTS TXS Trigger frame. Also in Figure 19, for example, STA 2 may transmit a CTS frame and data signal destined for another STA (e.g., STA 3) on the channel allocated to STA 2 for the TXOP sharing allocation period, based on the received MU-RTS TXS Trigger frame.

[0129] For example, in the example shown in Figure 19, AP100 communicates with one of the STAs (e.g., STA 1) to which TXOP sharing is applied during the TXOP sharing allocation period (e.g., receiving data signals and sending ACKs). In other words, in Figure 19, AP100 does not communicate with any other STA 2 that is different from STA 1 during the TXOP sharing allocation period. In this way, by instructing AP100 to communicate with one of the multiple STA200s to which TXOP sharing is applied during the TXOP sharing allocation period, overlapping transmission and reception timings of AP100 can be suppressed.

[0130] Furthermore, as shown in Figure 19, for example, the wireless parameters used for TXOP sharing can be determined (or scheduled) by the STA200 without the AP100 having to schedule them, thus enabling TXOP sharing for multiple STA200s with a simple process.

[0131] Figure 20 shows another example of a sequence when instructing multiple STA200s to perform TXOP sharing.

[0132] In Figure 20, a single trigger frame instructs TXOP sharing to three STA200s (e.g., STA 1, STA 2, and STA 3). Also, in Figure 20, for example, AP100 may use a MU-RTS TXS trigger frame to notify STA 1 and STA 2 with a P2P flag subfield value = 0, thereby instructing communication with AP100 during the allocation period, and to notify STA 3 with a P2P flag subfield value = 1, thereby instructing P2P communication during the allocation period. Furthermore, in Figure 20, AP100 may instruct STA 1, STA 2, and STA 3 to communicate on orthogonal frequency resources.

[0133] Furthermore, in Figure 20, AP100 may notify STA200 of information regarding the allocation period (e.g., UL Length) as common STA information. In other words, for example, the Common Info field of the MU-RTS TXS Trigger frame may include information regarding the duration (signal length) of signals transmitted by multiple STA200s during the allocation period of TXOP sharing (e.g., a portion of the TXOP). Each STA200 may determine the signal length of its data (e.g., SU PPDU) based on the information contained in the Common Info field.

[0134] For example, in Figure 20, since the P2P flag subfield value=1 (P2P communication) is set for STA 3, STA 3 may perform P2P communication with another STA (e.g., STA 4) during the allocated period notified by the UL Length subfield. For example, STA 3 may determine the size (signal length) of the data to be used for P2P communication within the allocated period.

[0135] Furthermore, for example, in Figure 20, since the P2P flag subfield value = 0 (communication with AP100) is set for STA 1 and STA 2 respectively, the signal length of the data signal destined for AP100 may be determined based on the allocation period notified by the UL Length subfield. For example, as shown in Figure 20, STA 1 and STA 2 may set the signal length of the data signal based on the period available for transmitting the data signal during the allocation period (for example, a period within the allocation period that is different from the transmission period of the CTS frame). Note that the method for determining the signal length of the data signal is not limited to this, and any determination method common to multiple STA200s is acceptable.

[0136] As a result, even when multiple STA200s communicate with AP100 in TXOP sharing, the signal length of the data signals transmitted by these multiple STA200s can be set to be the same. This ensures that the reception timing of data signals and the transmission timing of ACKs to multiple STA200s on AP100 are approximately the same, thus suppressing overlap between the transmission and reception timings on AP100.

[0137] In Figure 20, for example, overlapping transmission and reception timings can be suppressed in AP100, and time resources for communication with AP100 can be allocated to multiple STA200s. Also, in Figure 20, for example, other radio parameters that differ from the signal length of the STA200's transmission signal (e.g., UL Length) can be determined (or scheduled) by the STA200 without scheduling by AP100, so TXOP sharing for multiple STA200s can be implemented with simple processing.

[0138] In this embodiment, AP100 generates a trigger frame containing information for allocating a portion of the TXOP time acquired by AP100 to multiple STA200s, and transmits it to the STA200s. The STA200s then control the uplink transmission in TXOP sharing to multiple STAs based on a single trigger frame. As a result, in this embodiment, TXOP sharing can be instructed to multiple STA200s with a single trigger frame, thereby improving the allocation efficiency in TXOP sharing.

[0139] Furthermore, in this embodiment, in FDM-based TXOP sharing to multiple STAs, the overlap between the transmission timing and reception timing at AP100 can be suppressed by switching the type of uplink communication (for example, communication with AP100 or P2P communication) for each of the multiple STA200 to which TXOP sharing is applied, or by notifying the signal length to the multiple STA200 that communicate with AP100.

[0140] Furthermore, in this embodiment, TXOP sharing to multiple STAs is notified to the STA200 based on the MU-RTS TXS Trigger frame format agreed upon in 11be Release 1 (in other words, the format defined in 11be Release 1). This allows a common Trigger frame format to be applied to, for example, an STA corresponding to 11be Release 1 that supports TXOP sharing to one STA (for example, referred to as an "11be Release 1 compatible STA") and an STA that supports TXOP sharing to multiple STA200s in this embodiment (for example, an STA that supports future versions). For example, by using the MU-RTS TXS Trigger frame format described in this embodiment, the 11be Release 1 compatible STA can set the corresponding TXOP sharing mode (for example, a value of 0, 1, or 2) (in other words, limit the setting to a certain range of values), and the AP100 can notify the 11be Release 1 compatible STA of the TXOP sharing mode.

[0141] (Embodiment 2) This embodiment describes a case where TXOP sharing is performed to multiple STAs using TDM (Time-Delayed Multiplexing).

[0142] Figure 21 shows an example sequence in which an AP performs TXOP sharing to multiple STAs (e.g., STA 1 and STA 2) using MU-RTS TXS Trigger frames supported in 11be Release 1 as described in Non-Patent Literature 1. As shown in Figure 21, in 11be Release 1, only one STA can be instructed to perform TXOP sharing with a single MU-RTS TXS Trigger frame. Therefore, multiple MU-RTS TXS Trigger frames are used to instruct TXOP sharing to multiple STAs. The use of multiple MU-RTS TXS Trigger frames increases overhead and may reduce throughput performance.

[0143] This embodiment describes a method for performing TXOP sharing to multiple STAs based on TDM using a single MU-RTS TXS Trigger frame.

[0144] [Configuration of the wireless communication system] The wireless communication system according to this embodiment may include AP100 and STA200, similar to Embodiment 1.

[0145] [Base station configuration] The configuration example of AP100 according to this embodiment may be the same as that shown in Figure 12. For example, in AP100 according to this embodiment, the operation of the Common Info generation unit 103 and the User Info generation unit 104 may differ from that of Embodiment 1.

[0146] The Common Info generation unit 103 generates information in the TXOP sharing mode subfield, including TXOP sharing to multiple STAs based on TDM, based on information input from the TXOP sharing mode setting unit 102 (e.g., the TXOP sharing mode table). For example, when performing TXOP sharing as in Embodiment 1, the Common Info generation unit 103 may generate information in the Common Info field of the MU-RTS TXS Trigger frame by setting the Trigger type subfield to MU-RTS and setting the TXOP sharing mode subfield to the value associated with the TXOP sharing to be performed. The Common Info generation unit 103 may also include information regarding the allocation period to the STA200 in one of the subfields within the Common Info field (e.g., the UL length subfield) (examples will be described later).

[0147] The User Info generation unit 104 may generate information for the User Info field based, for example, on the allocated radio resources (allocation period) within the TXOP sharing applied to each STA200 input from the scheduling unit 101. Alternatively, the User Info generation unit 104 may generate a User Info List by arranging the User Info fields corresponding to each STA200 in the order of the STA200s allocated in the time domain, based on the allocated radio resources (allocation period) within the TXOP sharing. In other words, the AP 100 may associate the transmission order of multiple STA200s in at least a portion of the TXOP time with the arrangement order of individual User Info fields for multiple STA200s in the Trigger frame.

[0148] The processing of other components in AP100 may be the same as, for example, the processing in Embodiment 1.

[0149] [Device Configuration] The configuration example of the STA200 according to this embodiment may be the same as that shown in Figure 14. For example, in the STA200 according to this embodiment, the operation of the Common Info acquisition unit 205, the User Info acquisition unit 206, and the TXOP sharing control unit 207 may differ from that of Embodiment 1.

[0150] The Common Info acquisition unit 205, for example, similar to Embodiment 1, acquires the instruction information of the TXOP sharing mode subfield included in the Common field of the Trigger frame input from the error correction decoding unit 203 as STA common information when the Trigger type of the Trigger frame input from the Trigger frame is MU-RTS. For example, the STA common information may include information indicating the TXOP sharing mode for multiple STAs based on TDM.

[0151] The User Info Acquisition Unit 206 may, for example, perform reception processing of multiple User Info fields when the information indicating the TXOP sharing mode input from the Common Info Generation Unit 103 instructs TXOP sharing to multiple STAs, similar to Embodiment 1. For example, in the case of a TDM-based TXOP sharing mode to multiple STAs, the User Info Acquisition Unit 206 outputs the STA ID (e.g., AID) of each User Info field, the transmission order of the User Info fields in the User Info List, and information regarding the User Info field instructed to the STA 200 to the TXOP sharing control unit 207.

[0152] The TXOP sharing control unit 207 may, for example, determine (or judge) the allocated wireless resource (e.g., allocation period) based on the individual STA information and common STA information input from the User Info acquisition unit 206, and control data transmission in accordance with the TXOP sharing instructed by the AP100 (examples will be described later).

[0153] For example, in a TDM-based TXOP sharing mode to multiple STAs, the TXOP sharing control unit 207 may determine the frequency resource position of the transmitted signal based on carrier sensing by the STA 200. For example, the TXOP sharing control unit 207 may set the transmission band to a band within the Operation band, including Primary 20MHz, where carrier sensing has been cleared. The TXOP sharing control unit 207 may also determine the time resource position (e.g., transmission timing) of the transmitted signal based on the transmission order of the User Info fields in the User Info List input from the User Info acquisition unit 206.

[0154] The processing of other components in STA200 may be the same as, for example, the processing in Embodiment 1.

[0155] [Examples of AP100 and STA200 operation] Next, we will describe examples of the operation of AP100 and STA200 according to this embodiment.

[0156] The following describes how to instruct multiple STA200s to perform TDM-based TXOP sharing using a single trigger frame generated by the AP100 (for example, a MU-RTS TXS trigger frame).

[0157] The following describes an example of notifying each of the multiple STA200 units of the time resources (e.g., transmission timing or signal length) of the signal during their respective allocation periods.

[0158] <Notification Example 1> In Notification Example 1, the STA200 may determine the time resources (e.g., transmission timing) allocated to the STA200 based on the transmission order of the User Info fields included in the User Info List.

[0159] For example, in the User Info List, the STA200 indicated by the first User Info field (excluding the Special User Info field) may send a CTS frame + SIFS followed by a SU PPDU during its first transmission within the allocated period, and for subsequent transmissions within the allocated period, it may send a SU PPDU after receiving a signal from AP100 addressed to the STA200 (e.g., Block Ack) + SIFS.

[0160] Furthermore, for example, in the User Info List, the STA200 indicated by the Mth User Info field (where M is an integer greater than 1) among the User Info fields excluding the Special User Info field will transmit SU PPDU after receiving the signal transmitted from the STA200 indicated by the M-1th User Info field + SIFS. In this way, the STA200 indicated by the Mth User Info field may, for example, determine the transmission timing for that STA200 by first identifying the STA ID (e.g., AID) of the M-1th User Info field and detecting the signal of the STA ID assigned to the User Info field immediately preceding that STA200.

[0161] Furthermore, AP100 may notify users of information regarding the total time resources to be allocated to multiple STA200s, for example, through a Common Info field (e.g., UL Length subfield).

[0162] An STA200 that has decided to transmit within the allocated period may determine the signal length of the transmitted signal based on its transmit buffer information and transmit it, for example, within a range smaller than the total time resources allocated by AP100 (for example, the allocated period for Time allocated in MU-RTS TX TF in Figure 22). In this case, the STA200 can freely determine the signal length, but since each STA200 determines the signal length in the transmission order notified by AP100, an STA200 with a later transmission order may not be able to transmit within the allocated period.

[0163] Furthermore, for example, an STA200 that has decided to transmit within the allocated period may determine the signal length of the transmitted signal within the time resources obtained by dividing the total time resources allocated by AP100 equally among the allocated number of STAs (the number of User Info fields included in the MU-RTS TXS Trigger frame), and then transmit. In this case, the signal length determined by the STA200 is set (for example, limited) by the total time resources and the number of STAs, but all allocated STA200s can transmit within the allocated period.

[0164] Furthermore, in Notification Example 1, for example, communication to AP100 is set for communication during the allocation period, and P2P communication does not need to be set. This setting makes it easier to identify the STA ID of another STA that will send a data signal (SU PPDU) immediately before STA200 sends the data signal (SU PPDU).

[0165] Figure 22 shows an example of a sequence when performing TXOP sharing to multiple STAs in Notification Example 1.

[0166] In Figure 22, AP100 instructs STA 1 and STA 2 to perform TXOP sharing, for example, using a MU-RTS TXS Trigger frame. In Figure 22, as an example, in the User Info List included in the MU-RTS TXS Trigger frame, STA 1 is assigned by the first User Info field and STA 2 is assigned by the second User Info field.

[0167] As shown in Figure 22, STA 1, which is scheduled in the first User Info field, may send a signal (e.g., a CTS frame or SU PPDU) to AP100 after receiving a signal from AP100 (e.g., a MU-RTS TXS Trigger frame or a Block Ack).

[0168] Furthermore, as shown in Figure 22, STA 2, which is scheduled in the second User Info field, may send a signal (e.g., a CTS frame or SU PPDU) to AP100 after receiving a signal (e.g., a SU PPDU) transmitted from STA 1.

[0169] In Notification Example 1, each STA200 determines its transmission timing during the allocation period based on the transmission order of the User Info field to multiple STA200s within the MU-RTS TXS Trigger frame. In other words, the transmission timing (or transmission order) of each STA200 during the allocation period is implicitly notified to each STA200 by the transmission order of the User Info field. Therefore, according to Notification Example 1, it is possible to achieve TDM-based TXOP sharing to multiple STAs using a single MU-RTS TXS Trigger frame while suppressing the increase in overhead.

[0170] In Figure 22, for example, if STA 2 does not detect the signal from STA 1, STA 2 does not need to send SU PPDU to AP100. If STA 2 does not send SU PPDU, for example, the time during which AP100's carrier sense is idle exceeds PIFS, so AP100 may take action to retrieve the TXOP from STA200. After that, AP100 may, for example, reschedule TXOP sharing to STA 2. Alternatively, AP100 may, for example, send a CF-End (Contention Free - End) frame and discard the acquired TXOP.

[0171] <Notification Example 2> In Notification Example 2, similar to Notification Example 1, the STA200 may determine the time resources (e.g., transmission timing or allocation order) to be allocated to each STA200 during the allocation period based on the transmission order of the User Info field in the User Info List.

[0172] Notification Example 1 describes the operation by which an STA200 determines the signal length of its transmission signal (SU PPDU). In Notification Example 2, AP100 may set information in the Trigger frame indicating the duration of uplink transmission by multiple STA200s for at least a portion of the TXOP time. The signal length of the STA200's transmission signal may be notified to multiple STA200s from AP100 in common, for example, using a Common Info field (e.g., UL length subfield).

[0173] Furthermore, radio parameters (including, for example, MCS and spatial stream count) that differ from the signal length of the STA200's transmission signal may be determined by the STA200.

[0174] Figure 23 shows an example of a sequence when performing TXOP sharing to multiple STA200s in Notification Example 2.

[0175] In Figure 23, AP100 instructs STA 1 and STA 2 to perform TXOP sharing, for example, using a MU-RTS TXS Trigger frame. In Figure 23, as an example, in the User Info List included in the MU-RTS TXS Trigger frame, STA 1 is assigned by the first User Info field and STA 2 is assigned by the second User Info field.

[0176] Furthermore, in Figure 23, AP100 notifies STA200 of information regarding the signal length T [us] using, for example, the Common Info field of the MU-RTS TXS Trigger frame.

[0177] In this case, as shown in Figure 23, STA 1, which is scheduled in the first User Info field, may, after receiving the MU-RTS TXS Trigger frame from AP100, for example, after CTS frame transmission + SIFS, transmit a T[us] length transmission signal (SU PPDU).

[0178] Furthermore, as shown in Figure 23, STA 2, which is scheduled in the second User Info field, may, after receiving the MU-RTS TXS Trigger frame from AP100, transmit a transmission signal (SU PPDU) of length T[us] after, for example, CTS frame transmission + SIFS + T[us] + SIFS.

[0179] According to Notification Example 2, similar to Notification Example 1, it is possible to suppress the increase in overhead and achieve TDM-based TXOP sharing to multiple STAs by using a single MU-RTS TXS Trigger frame.

[0180] Furthermore, in Notification Example 2, each STA200 determines the time resource of the transmission signal based on the information contained in the Common Info field. Therefore, the allocation start timing for that STA200 can be determined without decoding other User Info fields that differ from the User Info field for that STA200. Thus, in Notification Example 2, the reception processing of the STA200 can be simplified compared to Notification Example 1.

[0181] Furthermore, in Notification Example 2, the time resource (signal length) of the transmitted signal is set (e.g., limited) for all STA200 units, so the allocated period does not need to be notified in the User Info field, thus reducing overhead.

[0182] Furthermore, for example, the total allocation period for multiple STA200s may be notified as information regarding the time resources of the STA200's transmission signal, as notified in the Common Info field. In this case, the STA200 may calculate its individual allocation period by dividing the total allocation period equally among the number of User Info fields (in other words, the number of multiple STA200s).

[0183] <Notification Example 3> In Notification Example 3, similar to Notification Example 1, the STA200 may determine the time resources (e.g., transmission timing or allocation order) to be allocated to each STA200 during the allocation period based on the transmission order of the User Info field in the User Info List.

[0184] In notification example 3, AP100 may set information in the Trigger frame indicating the duration of uplink transmission by multiple STA200s for at least a portion of the TXOP time. The signal length of the STA200 transmission signals may be individually notified from AP100 to each of the multiple STA200s, for example, using the User Info field.

[0185] Furthermore, radio parameters (including, for example, MCS and spatial stream count) that differ from the signal length of the STA200's transmission signal may be determined by the STA200.

[0186] Figure 24 shows an example of the User Info field in Notification Example 3.

[0187] As shown in Figure 24, the User Info field may include, for example, information regarding the signal length of the STA200's transmission signal (e.g., PPDU length subfield). The User Info field may also include, for example, information regarding the transmission start timing in the STA200 (e.g., Transmission start timing subfield). This information may be placed in different areas of the User Info field from the AID12 subfield and the RU allocation subfield, respectively. For example, in Figure 24, the PPDU length subfield and the Transmission start timing subfield are set in areas B25 to B38 (for example, in Figure 3, these areas correspond to the Reserved area, the SS Allocation / RA-RU Information subfield, and the UL Target Receive Power subfield).

[0188] Note that the area (e.g., position and size) in which the PPDU length subfield and Transmission start timing subfield are placed in the User Info field is not limited to the example shown in Figure 24. Also, the transmission start timing (Transmission start timing subfield) does not need to be notified. If the transmission start timing is not notified, STA200 may determine (e.g., calculate) its own transmission start timing by, for example, receiving (e.g., decoding) the User Info field of another STA that was transmitted before the User Info field that STA200 is scheduled to transmit.

[0189] Figure 25 shows an example of a sequence when performing TXOP sharing to multiple STA200s in Notification Example 3.

[0190] In Figure 25, AP100 instructs STA 1 and STA 2 to perform TXOP sharing, for example, using a MU-RTS TXS Trigger frame. In Figure 25, as an example, in the User Info List included in the MU-RTS TXS Trigger frame, STA 1 is assigned by the first User Info field and STA 2 is assigned by the second User Info field.

[0191] Furthermore, in Figure 25, AP100 notifies, for example, in the User Info field of the MU-RTS TXS Trigger frame, information regarding the signal length T1 [us] for STA 1 and information regarding the signal length T2 [us] for STA 2.

[0192] In this case, as shown in Figure 25, STA 1, which is scheduled in the first User Info field, may, after receiving the MU-RTS TXS Trigger frame from AP100, for example, after CTS frame transmission + SIFS, transmit a T1 [us] length transmission signal (SU PPDU).

[0193] Furthermore, as shown in Figure 25, STA 2, which is scheduled in the second User Info field, may, after receiving the MU-RTS TXS Trigger frame from AP100, transmit a transmission signal (SU PPDU) of length T2 [us] after, for example, CTS frame transmission + SIFS + T1 [us] + SIFS.

[0194] In the example shown in Figure 25, the User Info field does not necessarily have to include the Transmission start timing subfield shown in Figure 24. In this case, STA 2 may determine the transmission timing of the transmission signal by obtaining the value of the PPDU length subfield (e.g., T1) of the User Info field of STA 1, which is positioned one position before STA 2. In this case, the increase in overhead of the User Info field can be suppressed.

[0195] Alternatively, in the example shown in Figure 25, the User Info field may include the Transmission start timing subfield shown in Figure 24. In this case, the User Info field for each STA200 may include information (T1 in the example in Figure 25) regarding the signal length of at least one STA whose transmission order (or arrangement order of the User Info fields) precedes STA 2. For example, in the example in Figure 25, STA 2 may determine the transmission timing of its transmission signal based on the value of the Transmission start timing subfield in STA 2's User Info field (e.g., the value corresponding to T1). In this case, STA200 does not need to process the User Info fields of other STAs, thus simplifying the processing of STA200.

[0196] According to Notification Example 3, similar to Notification Examples 1 and 2, it is possible to suppress the increase in overhead and achieve TDM-based TXOP sharing to multiple STAs using a single MU-RTS TXS Trigger frame.

[0197] Furthermore, according to Notification Example 3, for example, AP100 can determine the time allocation of transmission signals based on the transmission buffer status of each STA200, thereby improving the efficiency of time resource allocation and improving throughput.

[0198] The above explains the notification examples 1 to 3 regarding the allocation period.

[0199] Thus, in this embodiment, AP100 generates a trigger frame containing information for allocating a portion of the TXOP time acquired by AP100 to multiple STA200s, and transmits it to the STA200s. The STA200s then control the uplink transmission in TXOP sharing to multiple STAs based on a single trigger frame. As a result, in this embodiment, similar to Embodiment 1, TXOP sharing can be instructed to multiple STA200s with a single trigger frame, thereby improving the allocation efficiency in TXOP sharing.

[0200] Furthermore, in this embodiment, in TDM-based TXOP sharing to multiple STAs, the notification of the time resources (e.g., transmission order, transmission start timing, or signal length) of the transmission signals of each of the multiple STA200 to which TXOP sharing is applied can suppress the overlap between the transmission timing and reception timing at AP100.

[0201] In addition, as in this embodiment, when TXOP sharing to multiple STAs based on TDM, the transmission and reception timings at AP100 do not overlap, so the communication method during the allocation period (for example, the P2P flag subfield described in Embodiment 1) does not need to be notified in the User Info field.

[0202] Furthermore, as shown in Figures 22, 23, and 25, AP100 may send a response signal (e.g., a Multi-STA Block ACK) to the data from multiple STA200s after receiving data from multiple STA200s that are TXOP shared. This can reduce the overhead of the Block ACK sent from AP100, for example.

[0203] Alternatively, at the end of the TXOP-shared allocation period, AP100 may consolidate the ACK information for each STA200 during the allocation period and notify them via Multi-STA Block ACK. This can reduce the overhead of ACK notification by AP100, for example, and improve throughput performance.

[0204] Furthermore, the notification of response signals for data from multiple STA200s is not limited to a method of sending ACK information to multiple STA200s together; it may also be possible to notify ACK information to multiple STA200s individually.

[0205] Furthermore, while notification examples 1-3 describe an example in which the transmission timing of each STA200 is notified based on the transmission order in the User Info field within the MU-RTS TXS Trigger frame, the system is not limited to this, and the transmission timing (or time resource) of each STA200 may also be explicitly notified to the STA200 in the User Info field.

[0206] The embodiments of this disclosure have been described above.

[0207] (Other embodiments) (1) In the embodiments described above, as an example, a case was described in which a TXOP sharing mode for multiple STAs and a TXOP sharing mode for one STA200 are notified in the TXOP Sharing Mode subfield, as shown in Figure 13, but the invention is not limited to this. For example, the subfields used for notifying a TXOP sharing mode for multiple STAs and for notifying a TXOP sharing mode for one STA may be different.

[0208] For example, to notify multiple STAs of TXOP sharing mode, any subfield in the Common Info field shown in Figure 2 that is not used in the case of a MU-RTS TXS Trigger frame (for example, the Reserved area) may be used. For example, of the Common Info field shown in Figure 2, at least some of the subfields of MU-MIMO HE-LTF Mode, Number of HE-LTF Symbols and Midamble Periodicity, UL STBC, LDPC Extra Symbol Segment, AP Tx Power, Pre-FEC Padding Factor, PE Disambiguity, and UL Spatial Reuse and Doppler subfields may be used to notify multiple STA200s of TXOP sharing mode.

[0209] As an example, as shown in Figure 26, when the Trigger type is MU-RTS, the B34-B35 region (Pre-FEC Padding Factor subfield in Figure 2) may be set to notification information for TXOP sharing mode for multiple STAs (for example, TXOP Sharing Mode for multi-user subfield).

[0210] Figure 27 shows information (e.g., information in a table format) that indicates the association between the TXOP sharing mode for multi-user and the information indicating the TXOP sharing mode in the trigger frame. As shown in Figure 27, the TXOP sharing mode for multi-user may include the mode for notifying multiple STAs of TXOP sharing based on FDM as described in Embodiment 1 (e.g., TxOP Sharing Mode subfield value = 1), and the mode for notifying multiple STAs of TXOP sharing based on TDM as described in Embodiment 2 (e.g., TxOP Sharing Mode subfield value = 2).

[0211] This improves the flexibility of notifying multiple STA200s of TXOP sharing mode.

[0212] (2) In the embodiments described above, the case in which AP100 notifies multiple STA200s of TXOP sharing has been explained, but the device that notifies of TXOP sharing is not limited to STA.

[0213] For example, the method for notifying AP100 of TXOP sharing to multiple STA200s described in Embodiments 1 and 2 may be applied to the method for notifying the allocation of radio resources (time resources and frequency resources) from a Sharing AP to a Shared AP in Multi-AP Coordination transmission (cooperative communication between multiple APs).

[0214] Examples of multi-AP cooperative communication include "Coordinated-Frequency Division Multiple Access (FDMA)," in which different frequency resources are allocated between multiple APs, and "Coordinated-Time Division Multiple Access (TDMA)," in which different time resources are allocated between multiple APs. In these multi-AP cooperative communications, the notification method using the MU-RTS TXS Trigger frame described above may be used for allocating radio resources from a Sharing AP to a Shared AP.

[0215] For example, the TXOP sharing (wireless resource allocation) from AP100 to multiple STAs described above may be reinterpreted as wireless resource allocation (including TXOP sharing) from a Shared AP to multiple Sharing APs in multi-AP cooperative communication. For example, similar to the TXOP sharing from AP 1 to STAs 11 and 12 connected to AP 1 in each of the embodiments described above, the notification method using the MU-RTS TXS Trigger frame described in each of the embodiments described above may be used for wireless resource allocation from AP 1, which is a Shared AP, to APs 2 and 3, which are Sharing APs.

[0216] Furthermore, the TXOP sharing (wireless resource allocation) from the AP to multiple P2P STAs described above may be reinterpreted as wireless resource allocation (including TXOP sharing) from a Shared AP to multiple Sharing APs and pairs of STAs under those Sharing APs in multi-AP cooperative communication. For example, similar to the TXOP sharing from AP 1 to P2P pair 1 (e.g., STA 11 and STA 12) and P2P pair 2 (e.g., STA 13 and STA 14) connected to AP 1 in each of the embodiments described above, the notification method using the MU-RTS TXS Trigger frame of this embodiment may be used for wireless resource allocation from AP 1, which is a Shared AP, to pairs of AP 2, which is a Sharing AP, and STA 21 under AP2, and to pairs of AP 3, which is a Sharing AP, and STA 31 under AP3 in multi-AP cooperative communication.

[0217] Furthermore, when using MU-RTS TXS Trigger frames in multi-AP cooperative communication, the TXOP sharing mode for multi-AP cooperative communication may be explicitly notified. For example, the TXOP sharing mode for multi-AP cooperative communication may be notified in the Reserved area of ​​the TXOP Sharing Mode in the Common Info field shown in Figure 2. Alternatively, as in Figure 26, a subfield for notifying the TXOP sharing mode for multi-AP cooperative communication may be provided in a subfield of the Common Info field (for example, a subfield not used for transmitting CTS frames).

[0218] (3) In Embodiment 1, when AP100 instructs multiple P2P pairs (pairs of STA200 performing P2P communication) to perform FDM-based TXOP sharing, the following procedure may be performed between AP100 and STA200.

[0219] Here, the STA pair performing P2P is configured using a procedure called Tunneled Direct Link Setup (TDLS) in the 802.11 standard. In TDLS, the AP relays the exchange of TDLS request frames and TDLS response frames between the STA pair, thereby pre-configuring P2P communication. Since the configuration details in TDLS are exchanged as encapsulated data, the AP does not know the details of the P2P configuration, including which STA pair configured the P2P.

[0220] Therefore, in one embodiment of this disclosure, in order for AP100 to implement TXOP sharing for P2P communication, STA200, which performs P2P, is expected to notify (request) AP100 in advance of predetermined information.

[0221] For example, an STA200 performing P2P may notify AP100 of a P2P resource allocation request after configuring TDLS. As a P2P resource allocation request, STA200 may notify AP100 of, for example, the status of the P2P transmit buffer (Buffer Status Report). Also, after configuring TDLS, STA200 may notify AP100 that STA200 is an STA that has configured TDLS. Also, STA200 may notify AP100 of, for example, information about another STA that STA200 is communicating with for P2P (for example, STA ID). Also, STA200 may notify AP100 in advance of the capability regarding whether the STA pair performing P2P communication is capable of communicating on a secondary channel. Also, after configuring TDLS, if STA200 performs Off-channel (for example, configuring P2P communication outside of AP100's Operation Band), STA200 may notify AP100 of the Off-channel implementation.

[0222] Alternatively, instead of the STA200 notifying the AP100 of information after TDLS configuration, a Direct link configuration procedure for TXOP sharing may be specified in place of the TDLS configuration procedure specified in the 802.11 standard. In the Direct link configuration for TXOP sharing, for example, the AP100 may relay the exchange of request / response frames for Direct Link configuration between STA200s performing P2P, and the AP100, which supports TXOP sharing, may decode and interpret the contents of the request / response frame. For example, the request / response frame may include the frequency resources used in P2P communication (e.g., the 20 MHz subchannel used), information about the STA of the P2P communication destination, and capability information. In this case, for example, the Direct Link information may be notified to the AP100 at the same time as the Direct Link configuration.

[0223] This allows AP100 to schedule FDM-based TXOP sharing for STA pairs that have a transmit buffer for P2P. Furthermore, for example, STA pairs performing off-channel P2P cannot be scheduled within AP100's operation bandwidth, so AP100 may exclude such STA pairs from TXOP sharing.

[0224] Furthermore, P2P communication is not limited to communication on channels including the Primary 20MHz channel; during the allocated period under TXOP sharing, communication on secondary channels that do not include the Primary 20MHz channel may also be permitted.

[0225] For example, as shown in Figure 18, AP100 may use the notification of the frequency resource location of the CTS frame by MU-RTS to instruct the STA pair performing P2P to allocate 20MHz × N channels in the RU allocation subfield of the User Info field.

[0226] Furthermore, AP100 determines the frequency resources (channels) that the P2P communication STA pair will transmit and receive during the TXOP-shared allocation period and notifies the STA pair in advance. This eliminates the need for the STA pair to detect the channels on which they will transmit and receive signals, thus simplifying the reception processing of STA200.

[0227] Furthermore, the prior notification of the frequency resources (channels) used for transmission and reception during the TXOP-shared allocation period can be achieved by, for example, adapting the Off-channel setting mechanism used in TDLS to negotiate the channels used for transmission and reception between P2P STA pairs.

[0228] Furthermore, when instructing P2P communication during a TXOP-shared allocation period, AP100 may, for example, include the STA ID of the receiving STA in addition to the STA ID of the transmitting STA in the User Info field of the Trigger frame. For example, if the connected APs of the STA pair performing P2P communication are different, AP100, to which the transmitting STA is connected, will not know the information about the receiving STA. In this case, the transmitting STA may notify AP100 of the information about the receiving STA (e.g., STA ID, etc.) (for example, notification may be made mandatory).

[0229] This allows the STA pair performing P2P communication to decode the trigger frame and detect that each STA's STA ID has been specified, thereby deactivating NAV and enabling P2P communication within the TXOP-shared allocation period. Alternatively, the trigger frame may not include the STA ID of the receiving STA in the P2P communication. If the receiving STA detects that the STA ID of the P2P communication partner's STA has been specified in the trigger frame, it can deactivate NAV and perform P2P communication within the TXOP-shared allocation period.

[0230] (4) The sequence diagrams shown in each of the embodiments described above illustrate, as an example, the case in which a CTS frame is responded to a MU-RTS TXS Trigger frame, but the embodiments of this disclosure are not limited thereto. For example, AP100 may instruct STA200 via the Trigger frame whether or not to respond with a CTS frame. This makes it possible to omit the response of a CTS frame from STA200 in environments where the occurrence of hidden terminals is expected to be infrequent, thereby improving throughput performance.

[0231] (5) In each of the embodiments described above, the fields in which control information such as TXOP Sharing Mode, P2P flag, Transmission start timing, or PPDU length is placed are not limited to the fields described above, but may be placed in other fields.

[0232] Furthermore, in each of the embodiments described above, the field indicating the allocation period for TXOP sharing is not limited to the UL Length subfield, but may be any other subfield.

[0233] Furthermore, in each of the embodiments described above, the configuration of the Trigger frame and the configuration of the Common Info field and User Info field within the Trigger frame are not limited to the examples described above. For example, other configurations may be used in which at least one of the above-described fields is added or some subfields are deleted.

[0234] Furthermore, the FDM-based TXOP sharing to multiple STAs described in Embodiment 1 and the TDM-based TXOP sharing to multiple STAs described in Embodiment 2 may be combined. For example, the multiple STA200s allocated in TXOP sharing may be signal multiplexed on resources where at least one of the frequency resources and time resources differs during the allocation period.

[0235] Furthermore, in the embodiments described above, as an example, a case in which a MU-RTS TXS Trigger frame is used to notify multiple STAs of a Sharing AP, but the Trigger type for notifying multiple STAs of a Sharing AP is not limited to MU-RTS, and other Trigger types may be used, or Trigger types newly defined in future versions may be used.

[0236] Furthermore, in P2P communication, another STA notified by STA200 may be an STA under AP100 to which STA200 is connected, or an STA under a different AP than AP100 to which STA200 is connected.

[0237] Furthermore, although the above embodiment was described based on the 11be format as an example, the format to which one embodiment of this disclosure is applied is not limited to the 11be format. One embodiment of this disclosure may, for example, be applied to IEEE 802.11bd (NGV (Next Generation V2X)), which is the next-generation standard to the automotive standard IEEE 802.11p.

[0238] (6) Information indicating whether or not STA200 supports the functions, operations, or processes described in each of the embodiments described above may be transmitted (or notified) from STA200 to AP100 as, for example, STA200 capability information or capability parameters.

[0239] The capability information may include an information element (IE) that individually indicates whether STA200 supports at least one of the functions, operations, or processes shown in each of the embodiments described above. Alternatively, the capability information may include an information element that indicates whether STA200 supports any two or more combinations of the functions, operations, or processes shown in each of the embodiments described above. An information element is also simply called an element.

[0240] AP100 may, for example, determine (or decide or assume) which functions, operations, or processes are supported (or not supported) by the source STA200, based on capability information received from STA200. AP100 may perform operations, processes, or controls in accordance with the determination result based on the capability information. For example, AP100 may control TXOP sharing to multiple STAs based on capability information received from STA200.

[0241] Furthermore, the fact that STA200 does not support some of the functions, operations, or processes shown in each of the embodiments described above may be interpreted as meaning that such some functions, operations, or processes are restricted in STA200. For example, information or requests regarding such restrictions may be notified to AP100.

[0242] Information regarding the capabilities or limitations of STA200 may be defined, for example, in the standard, or it may be implicitly communicated to AP100 in association with information known to AP100 or information transmitted to AP100.

[0243] This disclosure can be implemented in software, hardware, or software in conjunction with hardware. Each functional block used in the description of the above embodiments may be implemented in part or in whole as an integrated circuit (LSI), and each process described in the above embodiments may be controlled in part or in whole by a single LSI or a combination of LSIs. An LSI may consist of individual chips, or it may consist of a single chip that includes some or all of the functional blocks. An LSI may have data inputs and outputs. Depending on the degree of integration, LSIs may be referred to as ICs, system LSIs, super LSIs, or ultra LSIs.

[0244] The method of integration is not limited to LSIs; it may also be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, FPGAs (Field Programmable Gate Arrays) that can be programmed after LSI manufacturing, or reconfigurable processors that allow for the reconfiguration of the connections and settings of circuit cells within the LSI, may also be used. This disclosure may be implemented as digital or analog processing.

[0245] Furthermore, if advancements in semiconductor technology or other derived technologies lead to the emergence of integrated circuit technologies that replace LSIs, then naturally, it would be possible to use those technologies to integrate functional blocks. The application of biotechnology, for example, is a possibility.

[0246] This disclosure is applicable to all types of devices, systems, and equipment having communication capabilities (collectively referred to as communication equipment). Communication equipment may include a radio transceiver and a processing / control circuit. A radio transceiver may include a receiver and a transmitter, or both as functions. A radio transceiver (transmitter, receiver) may include an RF (Radio Frequency) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or similar. Non-exclusive examples of communication devices include telephones (mobile phones, smartphones, etc.), tablets, personal computers (PCs) (laptops, desktops, notebooks, etc.), cameras (digital still / video cameras, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, digital book readers, telehealth / telemedicine devices, vehicles or mobile transport with communication capabilities (cars, airplanes, ships, etc.), and combinations of the above-mentioned devices.

[0247] Communication devices are not limited to portable or movable devices, but also include all kinds of non-portable or fixed devices, devices, and systems, such as smart home devices (appliances, lighting equipment, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0248] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0249] Furthermore, the communication device also includes devices such as controllers and sensors that are connected to or linked to a communication device that performs the communication functions described in this disclosure. For example, this includes controllers and sensors that generate control signals and data signals used by the communication device that performs the communication functions of the communication device.

[0250] Furthermore, communication equipment includes infrastructure facilities such as base stations, access points, and any other devices, devices, and systems that communicate with or control the aforementioned non-limited types of equipment.

[0251] An access point according to one embodiment of the present disclosure comprises a control circuit that generates a control signal for allocating at least a portion of the time of acquired transmission opportunities to uplink transmissions of multiple terminals, and a transmission circuit that transmits the control signal.

[0252] In one embodiment of the present disclosure, the plurality of terminals include terminals that perform terminal-to-terminal communication.

[0253] In one embodiment of the present disclosure, the control circuit sets information instructing the plurality of terminals to share the transmission opportunity in a common information field common to the terminals in the control signal.

[0254] In one embodiment of the present disclosure, when the control circuit sets information instructing the sharing of the transmission opportunity, it sets individual user information fields for the plurality of terminals in the control signal.

[0255] In one embodiment of the present disclosure, the control circuit sets information in the terminal-specific user information field of the control signal indicating whether the communication during at least a portion of the transmission opportunity is communication between the access point and the terminal, or communication between terminals.

[0256] In one embodiment of the present disclosure, the control circuit sets information regarding the duration of the uplink transmission signal for at least a portion of the transmission opportunity in a common information field common to the terminals in the control signal.

[0257] In one embodiment of the present disclosure, the control circuit associates the transmission order of the plurality of terminals for at least a portion of the transmission opportunity with the arrangement order of individual user information fields for the plurality of terminals in the control signal.

[0258] In one embodiment of the present disclosure, the control circuit includes information in the control signal that indicates the duration of uplink transmission by the plurality of terminals during at least a portion of the transmission opportunity.

[0259] In one embodiment of the present disclosure, the control circuit sets information indicating the duration of the uplink transmission in the control signal in at least one of a common information field common to the terminals and a user information field specific to the terminals.

[0260] A terminal according to one embodiment of the present disclosure comprises a receiving circuit for receiving a control signal to allocate at least a portion of the transmission opportunity time acquired by an access point to uplink transmissions of multiple terminals, and a control circuit that controls uplink transmissions for at least a portion of the transmission opportunity time based on the control signal.

[0261] In a communication method according to one embodiment of the present disclosure, the access point generates a control signal to allocate at least a portion of the time of the acquired transmission opportunity to uplink transmissions of multiple terminals, and transmits the control signal.

[0262] In a communication method according to one embodiment of the present disclosure, a terminal receives a control signal for allocating at least a portion of the transmission opportunity time acquired by an access point to uplink transmissions of multiple terminals, and controls uplink transmissions for at least a portion of the transmission opportunity time based on the control signal.

[0263] The disclosure contents of the specification, drawings, and abstract included in the Japanese application of Japanese Patent Application No. 2021-100141 filed on June 16, 2021 are all incorporated herein by reference.

Industrial Applicability

[0264] One embodiment of the present disclosure is useful for a wireless communication system.

Description of Signs

[0265] 100 AP 101 Scheduling Unit 102, 204 TXOP sharing mode setting unit 103 Common Info generation unit 104 User Info generation unit 105 Trigger frame generation unit 106, 209 Error correction encoding unit 107, 210 Modulation unit 108, 201 Wireless transceiver unit 109, 202 Demodulation unit 110, 203 Error correction decoding unit 111 STA information acquisition unit 200 Terminal 205 Common Info acquisition unit 206 User Info acquisition unit 207 TXOP sharing control unit 208 Data generation unit

Claims

1. An access point, A control circuit that generates a control signal for allocating at least a portion of the transmission time acquired by the access point to uplink transmissions of multiple terminals, A transmitting circuit that transmits the aforementioned control signal during the transmission opportunity acquired by the access point, An access point equipped with the following features.

2. The aforementioned plurality of terminals include terminals that perform terminal-to-terminal communication. The access point according to claim 1.

3. The control circuit sets information instructing the multiple terminals to share the transmission opportunity in a common information field common to the terminals in the control signal. The access point according to claim 1.

4. When the control circuit sets information instructing the sharing of the transmission opportunity, it sets individual user information fields for the multiple terminals in the control signal. The access point according to claim 3.

5. The control circuit sets information in the terminal-specific user information field of the control signal indicating whether the communication during at least a portion of the transmission opportunity is communication between the access point and the terminal, or communication between terminals. The access point according to claim 1.

6. The control circuit sets information regarding the duration of the uplink transmission signal during at least a portion of the transmission opportunity in a common information field common to the terminals in the control signal. The access point according to claim 1.

7. The control circuit associates the transmission order of the plurality of terminals for at least a portion of the transmission opportunity with the arrangement order of individual user information fields for the plurality of terminals in the control signal. The access point according to claim 1.

8. The control circuit sets information in the control signal that indicates the duration of uplink transmission by the plurality of terminals during at least a portion of the transmission opportunity. The access point according to claim 7.

9. The control circuit sets information indicating the duration of the uplink transmission in the control signal in at least one of a common information field common to the terminals and a user information field specific to the terminals. The access point according to claim 8.

10. The control signal is a Multi-User Request-To-Send Transmission opportunity sharing (MU-RTS TXS) trigger frame. The access point according to claim 1.

11. The transmission performed by the plurality of terminals causes one or more terminals other than the plurality of terminals to set a network assignment vector (NAV). The access point according to claim 1.

12. The access point is The access point generates a control signal to allocate at least a portion of the transmission time it has acquired to uplink transmissions of multiple terminals. The control signal is transmitted when the access point acquires the transmission opportunity. Communication method.

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