Method for wireless communication, wireless communication device, access point device, and program

Abstract

Methods, wireless communication devices, access point devices, and procedures for wireless communication are provided. Aspects of this disclosure generally relate to an enhanced multi-user (MU) uplink (UL) protocol in a wireless network that allows a station to select values ​​for transmission parameters in a multi-user transmission. More specifically, embodiments of the invention relate to a method for wireless communication, the method comprising: at a station (STA), receiving a trigger frame from an access point (AP) to trigger a multi-user (MU) transmission, wherein the trigger frame allocates resource units for the MU transmission for data transmission from the STA using a set of transmission parameters; having the STA select values ​​for the set of transmission parameters; and transmitting a data frame on the resource units of the MU transmission allocated to the STA by the AP using the values ​​selected by the STA.

Description

[0001] (This application is a divisional application of application filed on November 6, 2020, with application number 202080077532.9 and title "Method and apparatus for selecting transmission parameter values ​​in multi-user transmission".) Technical Field

[0002] This invention generally relates to wireless communication. Background Technology

[0003] Wireless communication networks are widely deployed to provide various communication services, such as voice, video, packet data, messaging, and broadcasting. These wireless networks can be multiple access networks capable of supporting multiple users by sharing available network resources. Examples of such multiple access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single Carrier FDMA (SC-FDMA) networks.

[0004] To address the increased bandwidth and reduced latency requirements of wireless communication systems in high-density environments, multi-user (MU) schemes are being developed to allow a single access point (AP) to schedule MU transmissions in a wireless network—that is, multiple simultaneous transmissions to or from non-AP stations. For example, the Institute of Electrical and Electronics Engineers (IEEE) adopted one such MU scheme in draft version 3.0 (D3.0) of the 802.11ax standard in June 2018.

[0005] Due to the characteristics of MU, the station has the opportunity to access the wireless medium through two access schemes: the MU scheme and the traditional Enhanced Distributed Channel Access - EDCA (single user) scheme.

[0006] The 802.11ax standard allows multiple Access Points (APs) capable of simultaneous basic transmissions to make MU downlink (DL) transmissions to various non-AP stations via so-called Resource Units (RUs). As an example, a Resource Unit, for instance, splits the communication channel of a wireless network in the frequency domain based on Orthogonal Frequency Division Multiple Access (OFDMA) technology. The allocation of an RU to a station is signaled at the beginning of the MU downlink frame by providing each RU with an Association Identifier (AID) for the non-AP station (obtained individually by each station during its association process with the AP) defined in the transmission opportunity.

[0007] The 802.11ax standard also allows AP-triggered MU uplink (UL) transmissions, where various non-AP stations can simultaneously send resource units to the AP through the formation of MU UL transmissions. To control MU UL transmissions by non-AP stations, the AP sends a control frame called a trigger frame (TF). Through this control frame, the AP uses a 16-bit association identifier (AID) assigned to the non-AP station during registration with the AP and / or uses a reserved set of AIDs specifying a particular group of non-AP stations to assign resource units to them.

[0008] The 802.11ax MU transmission scheme used is not suitable for bandwidth-demanding communication services, such as video-based services like gaming, virtual reality, and streaming applications. This is because all communication passes through the access point (AP), thus doubling the airtime used for transmission and also doubling the number of media accesses (and therefore the media access time).

[0009] The 802.11 network protocol's single-user (SU) scheme allows for direct link (DiL, also known as peer-to-peer (P2P) transmissions), where data (MAC) frames are addressed using the destination station's 48-bit IEEE MAC address. However, SU and MU schemes directly compete with each other for access to the wireless medium (MU scheme by the access point, SU scheme by non-AP stations). In high-density environments, this competition generates numerous unwanted collisions, reducing latency and overall usable data throughput.

[0010] More generally, 802.11 is considered unsuitable for direct link transmission and can improve conventionally specified MU transmission. Summary of the Invention

[0011] The broad objective of this invention is to improve this situation.

[0012] In order to take advantage of the high efficiency of transmission scheduling performed by APs in high-density environments, the inventors have considered allowing stations to control and signal the values ​​of transmission parameters while using resource units allocated in multi-user transmissions.

[0013] One aspect of this disclosure provides a method for wireless communication, comprising: at a station, i.e., a STA, receiving from an access point, i.e., an access point, a trigger frame for triggering a multi-user transmission, i.e., a MU transmission, wherein the trigger frame allocates resource units of the MU transmission for data transmission from the STA using a set of transmission parameters, and wherein the resource units occupy a frequency bandwidth that is a multiple of a 20 MHz channel; the STA selecting some or all of the values ​​for the set of transmission parameters; and transmitting a data frame on the resource units of the MU transmission allocated to the STA by the AP using the values ​​selected by the STA.

[0014] Another aspect of this disclosure provides a method for wireless communication, comprising: at a station (STA), receiving from an access point (AP) a trigger frame for triggering a multi-user transmission (MU) transmission, wherein the trigger frame allocates resource units for the MU transmission for data transmission from the STA using a set of transmission parameters, and wherein the resource units occupy a frequency bandwidth that is a multiple of a 20 MHz channel; determining a value for the set of transmission parameters; and transmitting a data frame on the resource unit using the determined value, wherein the determination comprises: selecting a value by the STA if one or more conditions are met, otherwise retrieving a value provided by the AP.

[0015] Another aspect of this disclosure provides a method for wireless communication, comprising: at a station, i.e., a STA, receiving from an access point, i.e., an AP, a trigger frame for triggering a multi-user transmission, i.e., a MU transmission, wherein the trigger frame allocates resource units for the MU transmission for data transmission from the STA using a set of transmission parameters, and wherein the resource units occupy a frequency bandwidth that is a multiple of a 20 MHz channel; determining a value for the set of transmission parameters; and transmitting a data frame on the resource unit using the determined value, wherein the determination is based on an indication from the AP of whether the STA is allowed to select a value for the set of transmission parameters.

[0016] Another aspect of this disclosure provides a method for wireless communication, comprising: at an access point (AP), transmitting a trigger frame to trigger a multi-user transmission (MU) transmission, wherein the trigger frame allocates resource units for the MU transmission for data transmission from a station (STA) using a set of transmission parameters, and wherein the resource units occupy a frequency bandwidth that is a multiple of a 20 MHz channel; and transmitting an indication of whether the STA is allowed to select values ​​of the set of transmission parameters for transmitting data on the resource units.

[0017] Another aspect of this disclosure provides a method for wireless communication, comprising: at a second access point (AP), receiving from a first AP a trigger frame for triggering a multi-user transmission (MU) transmission, wherein the trigger frame allocates resource units for the MU transmission for the second AP to manage data transmission using a set of transmission parameters, and wherein the resource units occupy a frequency bandwidth that is a multiple of a 20 MHz channel; the second AP selecting a value for the set of transmission parameters; and transmitting a data frame on the resource units allocated by the first AP for the MU transmission using the value selected by the second AP.

[0018] In the variant, data frames are sent by stations belonging to the Basic Service Set (BSS) managed by the second AP.

[0019] Another aspect of the invention relates to a non-transitory computer-readable medium that stores a program, which, when executed by a microprocessor or computer system in the device, causes the device to perform any of the methods defined above.

[0020] At least a portion of the method according to the invention can be implemented by a computer. Therefore, the invention can take the form of a completely hardware embodiment, a completely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which are generally referred to herein as a “circuit,” “module,” or “system.” Furthermore, the invention can take the form of a computer program product embodied in any tangible medium having computer-usable program code embodied therein.

[0021] Since this invention can be implemented in software, it can be embodied as computer-readable code provided to a programmable device on any suitable carrier medium. Tangible carrier media may include storage media such as hard disk drives, magnetic tape devices, or solid-state storage devices. Transient carrier media may include signals such as electrical signals, electronic signals, optical signals, acoustic signals, magnetic signals, or electromagnetic signals (e.g., microwave or RF signals). Attached Figure Description

[0022] Embodiments of the invention will now be described by way of example only and with reference to the following figures, in which:

[0023] Figure 1 This diagram illustrates a typical wireless communication system that can implement embodiments of the present invention;

[0024] Figure 2 This illustrates multi-user (MU) transmission based on trigger (TB);

[0025] Figure 3a The format of HE SU PPDU is shown;

[0026] Figure 3b The format of HE MU PPDU is shown;

[0027] Figure 3c This shows the format of HE TB PPDU;

[0028] Figure 4 An embodiment of the invention, according to a first aspect of the invention, is illustrated using a flowchart to show the result of implementing the configuration of its HETB PPDU transmission at a non-AP station as a received trigger frame.

[0029] Figure 5An embodiment of the invention, according to a second aspect of the invention, is illustrated using a flowchart to show the result of implementing the HETB PPDU transmission at a non-AP station as a result of receiving a trigger frame.

[0030] Figure 6 A flowchart illustrates an embodiment of the invention implemented at AP according to a second aspect of the invention;

[0031] Figure 7 The structure of the trigger frame according to an embodiment of the present invention is shown;

[0032] Figure 8a A transmission sequence according to an embodiment of the present invention is shown;

[0033] Figure 8b Another transmission sequence according to an embodiment of the present invention is shown, wherein the RU with an indicator has a width of 20 MHz;

[0034] Figure 8c Another transmission sequence according to an embodiment of the invention is shown, wherein an RU with an indicator set can be perceived as a frequency band allocation for a given set of stations;

[0035] Figure 8d Another transmission sequence according to an embodiment of the present invention is shown;

[0036] Figure 9a A schematic diagram of a communication device according to an embodiment of the present invention is shown;

[0037] Figure 9b A schematic representation of a wireless communication device according to an embodiment of the present invention; and

[0038] Figure 10 An embodiment of the invention implemented at the destination station is illustrated using a flowchart. Detailed Implementation

[0039] The techniques described in this paper can be used in various broadband wireless communication systems, including communication systems based on orthogonal multiplexing schemes. Examples of such communication systems include Space Division Multiple Access (SDMA) systems, Time Division Multiple Access (TDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, and Single Carrier Frequency Division Multiple Access (SC-FDMA) systems. SDMA systems can utilize sufficiently different directions to simultaneously transmit data belonging to multiple user terminals. TDMA systems can allow multiple user terminals to share the same frequency channel by dividing the transmitted signal into different time slots or resource units, where each time slot is allocated to a different user terminal. OFDMA systems utilize Orthogonal Frequency Division Multiplexing (OFDM), a modulation technique that partitions the entire system bandwidth into multiple orthogonal subcarriers or resource units. These subcarriers can also be referred to as frequency modulation, bins, etc. Using OFDM, each subcarrier can be modulated independently with data. SC-FDMA systems can use interleaved FDMA (IFDMA) to transmit on subcarriers with cross-system bandwidth distribution, localized FDMA (LFDMA) to transmit on blocks of adjacent subcarriers, or enhanced FDMA (EFDMA) to transmit on multiple blocks of adjacent subcarriers.

[0040] The teachings of this paper can be incorporated into various devices (e.g., stations) (e.g., implemented within the device or by the device). In some aspects, a wireless station implemented according to the teachings of this paper may include an access point (so-called AP) or may not include an access point (so-called non-AP station or STA).

[0041] An AP may include, be implemented as, or be referred to as a B-node, radio network controller (“RNC”), evolved B-node (eNB), 5G next-generation base station (gNB), base station controller (“BSC”), base transceiver station (“BTS”), base station (“BS”), transceiver function (“TF”), radio router, radio transceiver, basic service set (“BSS”), extended service set (“ESS”), radio base station (“RBS”), or any other term.

[0042] A non-AP station may include, be implemented as, or be referred to as a subscriber station, subscriber unit, mobile station (MS), remote station, remote terminal, user terminal (UT), user agent, user device, user equipment (UE), user station, or any other term. In some implementations, an STA may include a cellular phone, cordless phone, Session Initiation Protocol (“SIP”) phone, Wireless Local Loop (“WLL”) station, personal digital assistant (“PDA”), handheld device with wireless connectivity, or some other suitable processing device connected to a wireless modem. Accordingly, one or more aspects of the teachings herein may be incorporated into a telephone (e.g., a cellular phone or smartphone), a computer (e.g., a laptop computer), a tablet, a portable communication device, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music or video device, or a satellite radio), a Global Positioning System (GPS) device, or any other suitable device configured to communicate via wireless or wired media. In some aspects, a non-AP station may be a wireless node. Such wireless nodes can provide connectivity to or from networks (e.g., wide area networks or cellular networks such as the Internet) via wired or wireless communication links, for example.

[0043] Figure 1 A wireless communication system is illustrated in which several communication stations 101-107, 110 exchange data frames via a radio transmission channel 100 of a wireless local area network (WLAN) under the management of a central station (i.e., access point (AP) 110). In a variant, direct communication between STAs (referred to as Ad-hoc mode) can be achieved without using an access point. The radio transmission channel 100 is defined by an operating frequency band consisting of a single channel or multiple channels forming a composite channel.

[0044] An example of direct communication corresponding to current growth trends is peer-to-peer (P2P) transmission between non-AP stations (e.g., STA102 and STA 104 shown in the diagram). Technologies supporting P2P transmission include, for example, WiFi-Miracast (RTM) or wireless display scenarios, or Tunnel Direct Link Establishment (TDLS). Note that even though P2P streams are typically not numerous, the data volume of each stream can be enormous (typically low-compressed video, from 1080p60 to 8k UHD resolution).

[0045] Each STA 101-107 registers with AP 110 during the association process. During the association process, AP 110 assigns a specific association identifier (AID) to the requesting STA. For example, the AID is a 16-bit value that uniquely identifies the STA.

[0046] Stations 101-107 and 110 can compete with each other using EDCA (Enhanced Distributed Channel Access) to access the radio medium for a licensed transmission opportunity (TXOP) and then transmit (single-user, SU) data frames. Stations can also use a multi-user (MU) scheme, where a single station (typically AP 110) schedules MU transmissions in the wireless network, i.e., multiple simultaneous transmissions to or from other stations. One implementation of this MU scheme has been adopted, for example, in the IEEE 802.11ax revision as a multi-user uplink and downlink OFDMA (MU UL and DL OFDMA) procedure.

[0047] Figure 2 This illustrates a trigger-based (TB) multi-user (MU) transmission, which includes MU uplink (UL) transmissions to the AP as well as MU transmissions to the STA, i.e., direct link (DiL) transmissions.

[0048] The MU transmission shown is triggered by a trigger frame (TF) 210. The TF is a control frame in the IEEE 802.11 legacy non-HT format and is transmitted via the primary 20MHz channel 250 and replicated (reproduced) on each of the other 20MHz channels 251 forming the target composite channel. Due to the replication of the control frame, each nearby legacy station (non-HT or 802.11ac station) expected to receive the TF on the primary channel sets its NAV to the value specified in the header of the TF. This prevents these legacy stations from accessing the target composite channel during a transmission opportunity (TXOP).

[0049] The station that receives the trigger frame is called the triggered station, while the station that sends the trigger frame is called the triggering station.

[0050] In addition to allocating uplink (UL) capabilities (e.g., 221) through resource units (RU) 201, 203-208, Figure 2 The TF shown also provides DiL transmission capability within the triggered MU transmission (222) by allocating resource units (RU) 202.

[0051] Resource elements (201-208) are formed by a preferred set of adjacent subcarriers contained in a composite channel. This means that the frequency bandwidth of the composite channel is greater than or equal to the frequency bandwidth of the resource element. RUs can be allocated for scheduling or random access.

[0052] The triggered station can use the RU allocated by the trigger frame for direct link transmission toward the destination triggered station to directly send data frames using physical (PHY) preamble 230 to the destination triggered station. The destination triggered station can then receive the data frames on the RU allocated for DiL data transmission.

[0053] Once a station has sent data to the AP using scheduled and / or random RUs, the AP responds with a multi-user acknowledgment to confirm the data received on each RU. When sent on an OFDMA RU, the acknowledgment frame 240 may follow the NON_HTPPDU format (241) or the HE MU PPDU format (242).

[0054] For a DiL RU, it is conceivable that the destination station receiving the DiL can transmit an acknowledgment 260 within the same RU where the DiL transmission occurred. The acknowledgment frame 260 can follow the SU format, but must be located at the same RU location as the DiL RU.

[0055] High-efficiency (HE) frames have been introduced in 802.11ax. These frames begin with the same preamble (L-STF, L-LTF, and L-SIG) that can be read by any (backward compatible) station and continue with the preamble and data fields. The HE preamble can only be decoded by 802.11ax (and forward compatible) devices and is included in various types of HE frames, such as HE single-user (SU) PPDUs for single-user transmissions, HE MU (multi-user) PPDUs for transmissions to one or more stations (particularly for MU downlink (DL) transmissions from an AP to a non-AP station), and HE trigger-based (TB) PPDUs (He_Trig) for uplink (UL) transmissions from a non-AP station to an AP in response to a trigger frame.

[0056] Figure 3a , 3b Figures 3 and 3c illustrate the formats of HE SU PPDU, HE MU PPDU, and HE TB PPDU frames, respectively. These HE frames are used as examples in describing embodiments of the invention, but other formats are certainly conceivable. For example, the Extremely High Throughput (EHT) frames introduced in 802.11be can also be used well.

[0057] Figure 3aThe format of the HE SU PPDU is shown. In addition to the standard preamble (L-STF, L-LTF, L-SIG), it includes RL-SIG (repeated conventional signal field), HE-SIG-A (HE signal A), HE-STF (HE short training field), HE-LTF (HE long training field), data, and PE (packet extension) fields. The conventional preamble and HE-SIG-A are replicated on each 20MHz channel. The HE-SIG-A field includes several subfields indicating the set of transmission parameters of the PPDU, such as bandwidth (BW), modulation and coding scheme (MCS), number of data streams, and coding type.

[0058] Figure 3b The format of the HE MU PPDU is shown. It includes fields as part of the HE SU PPDU, where additional field 350 (i.e., HE-SIG-B (HE signal B)) is used to tell non-AP stations in which resource unit they will find their data. Therefore, HE-SIG-B 350 defines how the RUs forming the DL MU transmission are assigned to non-AP stations so that the latter can effectively receive their own data from the AP.

[0059] Figure 3c The format of the HE TB PPDU (HE-Trig) is shown. The HE-Trig frame has a format very similar to the HE SU PPDU, except that the duration of the HE-STF field is 8 μs. Specifically, the HE-SIG-B field is not included because the RU allocation for non-AP stations has already been defined in the trigger frame. Format 303 can be... Figure 2 The example frame (preamble and data) 230_221 is shown.

[0060] The fields of various types of HE frames can be classified into the first group of pre-HE modulation fields (360a, 360b, 360c) and the second group of HE modulation fields (361a, 361b, 361c).

[0061] In the HE TB PPDU, the pre-HE modulation field (360c), including the L-STF, L-LTF, L-SIG, RL-SIG, and HE-SIG-A fields, is transmitted only on the 20MHz channel where the STA's HE modulation field resides. If the HE modulation field resides on more than one 20MHz channel, the pre-HE modulation field is replicated on multiple 20MHz channels. This corresponds to... Figure 2 The value is represented by 230.

[0062] As a result of receiving the TF, the data transmission of the triggered station in RU 201-208 is performed using, for example... Figure 3cThe example shown is a HE-triggered PPDU (HE_Trig) or a variant thereof in each RU accessed by the station. This format is used as a transmission in response to a trigger frame (or an equivalent via the 802.11ax TRS mechanism representing trigger response scheduling). Each HE-Trig PPDU carries a single transmission (i.e., from a single station) in response to a trigger frame.

[0063] Various formats show that the station can know the RU forming the MU transmission and the RU allocation by the trigger frame that triggers uplink (UL) communication or the physical preamble field (HE-SIG-B field 350) of the HE MU PPDU used for downlink (DL) communication.

[0064] In addition, stations can transmit PPDUs in different formats based on sets of different transmission parameters (such as channel width, rate (or MCS, representing modulation and coding scheme)).

[0065] In the transmission parameter set, the HE-MCS parameter (that is, the MCS for HE or 802.11ax devices) is a compact representation of the modulation and coding used in the HE-SIG-B and data fields of the PPDU. For HE SU PPDU, the HE-MCS parameter is carried in the HE-SIG-A field. For HE MU PPDU, the HE-MCS parameter is carried per user in the user-specific field of the HE-SIG-B field. For HE TB PPDU, the HE-MCS parameter is carried in the user information field of the trigger frame requesting the HE TB PPDU. It can be noted that the MCS is usually indicated by the transmitting station of HE SU PPDU and HE MU PPDU, while the HE-MCS is indicated by the receiving station of HE TB PPDU (the receiving station is the AP, which transmits the TF that processes such parameters). Due to the addition of the new modulation technique (QAM-1024), two new MCS indices are now available for 802.11ax (MCS indices are now between 0 and 11).

[0066] The mandatory preamble 230 for regular MU transmissions is the same for all transmissions. More specifically, for 802.11ax, the pre-HE modulation field 360c (which constitutes preamble 230) is the same and is transmitted on each of the 20MHz frequency bands. Therefore, the values ​​of the transmission parameters (included in the HE-SIG-A field) are the same and do not represent the most appropriate values ​​that will be selected by the station for a given transmission.

[0067] This constraint reduces system performance when a station needs to select different values ​​for transmission parameters while benefiting from the RU allocated within the MU transmission.

[0068] In various aspects, embodiments of the present invention advantageously use the preamble of the data frame to transmit values ​​of transmission parameters suitable for each transmission when transmitting data frames in MU transmission.

[0069] According to one aspect, embodiments of the present invention specify that the STA selects values ​​for the set of transmission parameters to be used to send data frames.

[0070] Figure 4 A flowchart illustrates an example of a wireless communication method performed at a station according to an embodiment of the first aspect of the present invention.

[0071] In step 401, a trigger frame is received from the AP of the basic service set (first BSS) to trigger a multi-user (MU) transmission. The TF frame allocates a resource unit for the MU transmission, where the STA can access the resource unit to send data frames using a set of transmission parameters.

[0072] In step 403, the STA selects values ​​for a portion or all of the transmission parameter set, and in step 404, the STA uses the values ​​selected by the STA to transmit a data frame (HE TB PPDU) on the RU transmitted by the MU assigned to the STA by the AP.

[0073] Optionally, the execution of step 403 is conditional upon satisfying one or more conditions (step 402). If one or more conditions are not satisfied, the STA can retrieve the values ​​selected by the AP for the set of transmission parameters (step 405). In one implementation, these values ​​are retrieved from a trigger frame sent by the AP. For example, the AP-selected values ​​are retrieved from the user information field of the trigger frame as defined according to the IEEE 802.11ax standard.

[0074] According to one embodiment, a condition is that the resource units of the MU transmission are allocated for sending data frames from one STA to another in a direct link DiL. This advantageously allows the STA to select the most appropriate value for sending data frames toward the destination STA.

[0075] According to one embodiment, a condition is that resource units for MU transmissions are allocated to a station acting as an AP (second AP) relative to a second BSS other than the first BSS. A STA is considered an apparatus (e.g., a station unassociated with the first AP) relative to the first AP. The second AP uses the resource units for MU transmissions allocated to it to manage data exchange between the station and the second AP. The station managed by the second AP is a station of the second BSS, but the second AP can also sublease some or all of the allocated resource units to stations not belonging to the second BSS. This advantageously allows the second AP to select the most appropriate parameter values ​​for sending data frames to the destination station of the second BSS and / or for receiving data frames from the source station of the second BSS.

[0076] The first AP and the second AP can be part of an inter-AP coordination group, the formation of which is outside the scope of this invention (management frames, such as beacons or dedicated broadcast frames, may be considered for announcing multi-AP coordination capabilities). The first AP can be referred to as the coordinating AP, and the second AP can be considered as the coordinated AP. The first AP can use a dedicated identifier (such as the MAC address of a STA or the BSSID of a second BSS) to signal that a resource element has been assigned to a station acting as an AP. In fact, a station may not be associated with the first AP, and therefore the station does not have an AID assigned to it by the first AP.

[0077] According to one embodiment, a condition is that the resource element occupies a frequency band formed by multiple 20MHz channels (e.g., 20, 40, 60, 80, 160, 320MHz). Since the STA is the only transmitter in the 20MHz channels forming the frequency band, the STA's preamble is not superimposed with the preamble of one or more other STAs, thus the STA can freely and appropriately adjust the values ​​of the transmission parameters transmitted in the preamble.

[0078] According to one embodiment, a condition is that the value provided by the AP is not recognized by the STA, not supported by the STA, or cannot be satisfied by the STA.

[0079] According to one embodiment, one condition is that the STA is the only station transmitting the preamble on each of the 20MHz channels of the composite channel. In fact, since the transmission of a data frame includes transmitting a payload on a resource element and transmitting a preamble on each of the 20MHz channels of the composite channel, when the STA is the only station transmitting its preamble, the STA is free to choose the most appropriate value to transmit the data frame toward the destination AP or non-AP station (i.e., it is not forced to have the same preamble as other STAs).

[0080] Since the STA is allowed to select values ​​for a set of transmission parameters, the value selected by the STA for at least one transmission parameter can be different from the value selected by the AP, for example, as specified in the user information field.

[0081] In one embodiment, the STA is allowed to select values ​​for certain parameters from the set of transmission parameters, while the STA is not allowed to select certain other parameters in the set; that is, for the latter, the STA must use values ​​provided by the AP. For example, the AP might want to control the received signal strength (RSSI) of the signal to be transmitted by the STA by controlling the STA's transmit power, and therefore the AP would exclude that parameter from the set of transmission parameters that the STA is allowed to select. In a variant, the STA is allowed to select values ​​for some or all of the transmission parameters, but under constraints, such as as long as the parameter value remains within a certain range, the STA is allowed to select that parameter value.

[0082] In one embodiment, the data frame uses a single-user (SU) format on the resource unit of the MU transmission. In a particular implementation, the SU format used is the HE SU PPDU format according to the IEEE 802.11ax standard.

[0083] In one embodiment, the data frame uses a multi-user (MU) format on the resource unit of the MU transmission. In a particular implementation, the MU format used is the HE MU PPDU format according to the IEEE 802.11ax standard (alternatively, the EHT MU PPDU format may be envisioned according to the IEEE 802.11be standard). The MU format has an HE-SIG-B field that contains additional information (e.g., the sender's identifier), which the receiver of the UL HE MU PPDU can use to determine the sender of the PPDU even in cases where the data field of the PPDU has not been received.

[0084] In one embodiment, the data frame includes a trigger frame to trigger a (second) MU transmission from a station on a resource unit of a (first) MU transmission triggered by a first AP. In this embodiment, the triggered station is a second AP, different from the triggering AP (first AP).

[0085] According to another aspect, embodiments of the present invention assume that the STA determines the values ​​of the set of transmission parameters to be used for transmitting data frames based on an instruction from the AP. This instruction may indicate whether the STA is allowed to select the values ​​of the set of transmission parameters. In a variant, the instruction may indicate whether the values ​​of the set of transmission parameters used by the STA to transmit data on a resource unit are provided by the AP or selected by the STA.

[0086] Figure 5 A flowchart illustrates an example of a wireless communication method according to an embodiment of the second aspect of the invention, in which a station configures its HE TB PPDU transmission based on a received trigger frame.

[0087] In step 501, the STA receives a trigger frame that assigns a MU RU to which the STA can access to send data. The RU can be a scheduled RU or a random RU of the STA.

[0088] In step 502, the STA retrieves an indication from the AP indicating whether the STA is allowed to select a value. This indication is preferably retrieved from a field in the trigger frame.

[0089] The STA decodes the received trigger frame and determines the RU described in the trigger frame, which identifies the STA as the source station (for UL MU transmission or non-UL (i.e., DiL) MU transmission) or as the destination station for non-UL (i.e., DiL) MU transmission declared in the trigger frame.

[0090] This can be accomplished by analyzing the user information field 710 declared in the trigger frame 700, and more specifically, by analyzing the AID12 subfield 711 and / or the trigger dependent user Info subfield 714, where AP 110 uses the AID12 subfield 711 and / or the trigger dependent user Info subfield 714 to declare a DiL RU with the destination non-AP station and (if required for DiL) the source station. As an alternative to using AID to signal the stations involved in the RU, the MAC address of the station can be used instead of signaling.

[0091] In an embodiment, in the RU allocation list provided by trigger frame 700, at most one RU is eligible for (DiL) reception of STA.

[0092] In an embodiment, in the RU allocation list provided by trigger frame 700, at least one RU is eligible for (DiL) transmission of STA.

[0093] In one embodiment, the RUs qualified for (DiL) reception and the RUs qualified for (DiL) transmission are mutually exclusive, so that the STA can receive or transmit, but not both simultaneously.

[0094] In step 503, the STA determines the values ​​of the transmission parameter set based on the indication, and in step 504, the STA uses the determined values ​​to transmit a data frame on the RU assigned by the AP. The data frame is sent to the AP or another STA (or multiple STAs).

[0095] In the embodiment of step 503, if the STA is determined to be the source triggering station of the RU with an indicator specifying the value of the transmission parameters determined by the STA, the STA selects a value in a similar manner to when the STA has already selected a value for transmission using EDCA (e.g., transmitting data frames in single-user mode). For example, the MCS is selected based on the signal quality perceived by the destination station. The PHY preamble will have the same width as the associated data.

[0096] In embodiments where the RU has a 20MHz width (e.g., as via...), Figures 8b to 8dAs mentioned above, the PHY preamble will also have a 20MHz width, while the associated data will have a narrow width. For example, an empty 26-frequency modulation RU can be considered at one (or both) boundaries of the 20MHz channel to reduce interference from / towards adjacent 20MHz channels.

[0097] In one embodiment, the UL target RSSI subfield can be considered by the STA. The value of the target RSSI, in dBm, indicates the expected received power across all antennas at the AP for the allocated resource element transmission from the uplink 802.11ax client. Based on this information provided by the trigger frame, the STA can adjust its selected MCS to match the transmit power requested by the AP.

[0098] All embodiments and variations described with respect to the first aspect also apply to this second aspect of the invention. For example, if the STA is allowed to select a value, the selection may be limited to a subset of the transmission parameters and / or a range of values.

[0099] Figure 6 A flowchart is used to illustrate an embodiment of the invention implemented at AP according to a second aspect of the invention.

[0100] In step 601, the AP sends a trigger frame to trigger a multi-user (MU) transmission. The TF allocates resource units for the MU transmission using the set of transmission parameters from the STA.

[0101] In the case of DiL transmission, various methods can be envisioned to identify (one or more) stations involved in the transmission. The following example can be considered.

[0102] As described above, according to 802.11ax, the RU is typically associated with an identifier (referred to as "AID12") within the trigger format (e.g., the "Per-User Info" field of the RU embeds the "AID12" field set to the AID of the source station). In one implementation, AID12 can be used to transmit a session identifier corresponding to a direct link session (thus obtaining the source and destination stations involved in the direct link communication). This is conceivable when the AP has already allowed P2P sessions (as in the case of the DLS protocol) and has already assigned an identifier to the session. In a preferred approach, the session identifier is constrained to a 12-bit AID format; the AP then assigns a value different from the value assigned to the AID identifying each station.

[0103] Alternatively, several AIDs can be signaled for a given RU, which would allow notification of both the source and receiving P2P stations. Alternatively, for unestablished direct link sessions, the AID of the peer non-AP 802.11ax destination station might be unknown to the non-AP 802.11ax station. Therefore, it is conceivable to use MAC addresses instead of station identifiers (AIDs), as these addresses are generally known and more specifically shared by the AP and stations (since the AP already allows registration to peer non-AP 802.11ax destination stations on the BSS). The AP can also retrieve the AID from the received MAC addresses and announce the station's AID for subsequent resource allocation.

[0104] Alternatively, a given RU can be associated with a different BSSID (for example, the AID12 field contains a specific AID value corresponding to a different BSSID; alternatively, a value for the expected BSSID can be provided for the MAC address). Therefore, the AP corresponding to the specified BSSID is the triggered station. As a result, the second AP can send frames within the given RU provided by the first AP to the station associated with the BSSID specified by the second AP.

[0105] In step 602, the AP sends an indication of whether the STA is allowed to select values ​​for the set of transmission parameters used to transmit data on the allocated resource unit. Alternatively, the indication may indicate whether the values ​​for the set of transmission parameters used by the STA to transmit data on the resource unit need to be values ​​provided by the AP, or whether the selection of values ​​is left to the STA.

[0106] The decision to include such an indicator element for station transmission mode in a given RU can be based on various criteria at the AP, such as previous buffer status reports received from non-AP stations. In a variant, the RU allocated for DiL transmissions can always have a set of indicator elements.

[0107] Preferably, the number of UL RUs with configured indicator elements is included in the number of available PHY block transmission chains at the AP (the AP may have several radio and antenna systems). The AP will not limit the number of DiL RUs (or RUs intended for use with other BSSs) with indicator elements configured for its receiving capabilities, since the AP is not a receiving station for such RUs.

[0108] In a preferred embodiment, the AP will make UL RUs with unset indicator elements (or RUs without indicator elements) consecutive, so that a single block transport chain is used to decode all ranges of UL RUs (because those UL RUs share the same PHY preamble).

[0109] Then, the trigger frame is sent by the AP's PHY to the triggered STA (usually a non-AP station of its BSS, but it can also be any AP that manages its own different BSS).

[0110] Optionally, in step 603, if the assigned RU is an uplink RU, the AP receives data frames on the RU assigned to the STA by the AP using a value determined based on an indication.

[0111] If the assigned RU is a DiL RU, the destination STA receives data frames on the RU assigned to the STA by the AP using values ​​determined based on the indication.

[0112] If the assigned RU is a RU for a different BSS, the destination STA receives data frames on the RU of the AP assigned by the AP to the second BSSID using a value determined by the indication.

[0113] Figure 7 The structure of a trigger frame 700 according to an embodiment of the present invention is shown. In this example embodiment, the TF includes an explicit indication field.

[0114] An embodiment of the present invention provides a trigger frame in which the user information field 710 is a variant of the 802.11ax user information field; and bit B39 (previously unused) is used as an indicator to specify to the triggered STA that its own transmission parameters must (or must not) be considered when publishing an HE PPDU in the corresponding RU.

[0115] Subfield B39 is a signal notification element that can be named “Transmission Mode” or “STA TX Parameter” or any other appropriate name.

[0116] According to an embodiment, the B39 subfield 713 includes a value specifying that the transmission parameter value contained in the TF must be used (e.g., B39 is not set, or the value is 0). According to an embodiment, the trigger frame parameters to be considered are the MCS subfield 715 and the target RSSI subfield 716.

[0117] B39 subfield 713 includes a value that specifies that the triggered STA will not use the transmission parameters indicated in the trigger frame, but must instead use its own locally determined (selected) transmission parameter values ​​(e.g., setting B39, or value 1).

[0118] Therefore, the use of subfield B39 is advantageously compatible with the existing 802.11ax TF format for backward compatibility.

[0119] User information field 710 may also include AID12 subfield 711 and trigger-related user information subfield 714.

[0120] According to other embodiments, where embodiments of the invention are applied only to direct link RU communication (and never to UL RU), explicit signaling is not required; the determination of the RU as a direct link RU is used to determine if a means of signaling is enabled. As already discussed, AID12 711 can transmit a session identifier corresponding to the direct link session, or two AID12s can be specified to identify two P2P non-AP stations, or alternatively, two MAC addresses can be specified.

[0121] According to other embodiments, when the triggered STA is the second AP, explicit signaling is not required. The use of the BSSID (or a value derived therefrom) of the second AP used for RU allocation is sufficient to determine that signaling has been set. As already discussed, AID12 can transmit a MAC address that is a different BSSID from the MAC address (BSSID) of the triggering AP.

[0122] Figure 8a The transmission sequence according to an embodiment of the present invention is shown.

[0123] Trigger frame 210 has a non-HT copy format and is copied on each of the 20MHz channels (e.g., 40MHz for illustration) that form the operation reserved frequency band.

[0124] Preferably, the conventional MU UL RU is designated to occur on the primary 20MHz channel (i.e., the channel on which the AP has already competed for its medium access). For those RUs, no indication is provided as to whether the transmission parameter values ​​used to send data on the RU are set by the AP or by the source station.

[0125] As a result, non-AP stations (STA1, STA7, STA3, and STA5) will transmit UL frames according to the HE TB PPDU. Figure 3c ), where all pre-modulated fields 360c are transmitted by the station over a 20MHz width.

[0126] Preferably, the RUs (RU5 and RU6) on the secondary channel have an indication set according to an embodiment of the invention (which indicates whether the transmission parameter values ​​for sending data on the RU are set by the AP or by the source station).

[0127] As a result, non-AP stations (STA2 and STA6) will be based on HE SU PPDU ( Figure 3a The trigger frame is transmitted, in which each premodulation field 360a is transmitted by the station on the same frequency width as the determined RU. This is because the format contains parameters useful for the receiver to decode the PPDU (by analyzing the HE-SIG-A field).

[0128] Station STA2 transmits its frame 822 along RU5 in HE SU PPDU format. Station STA2 indicates the value of the selected transmission parameter in the HE-SIG-A field.

[0129] After decoding the conventional preamble, the PHY entity at the receiving station should begin receiving the sequences of HE-SIG-A, HE-STF, and HE-LTF for the HE SU PPDU; the receiving station evaluates HE-SIG-A for the supported modes (checking the contents of HE-SIG-A). The HE-MCS, representing modulation and coding, is specifically carried in the HE-SIG-A field, thus allowing the receiving station to correctly decode the subsequent HE modulation field 361a.

[0130] In the same manner, station STA6 transmits its frame 821 along RU6 in HE SU PPDU format.

[0131] Note the difference from the conventional triggering mechanism of the 802.11ax standard; the preambles 230, 830, and 831 in the figure are different. The new triggering mechanism of this embodiment provides the use of various preambles in the RU; the conventional pre-HE modulation field 360c (for 230) or the pre-HE modulation field 360a (for 830 and 831).

[0132] In an embodiment, data frames sent by STA2 or STA6 may use a multi-user (MU) format, in which only one STA (STA2 or STA6) is listed in the HE-SIG-B field.

[0133] Next, the receiving stations (STA4 and AP in this example) can acknowledge the transmission on the OFDMA RU using ACK or block ACK frames (842 and 841, respectively). Preferably, these ACK frames are also sent in SU PPDU format.

[0134] In conclusion, RU characteristics such as position, width, and length are still indicated by the trigger frame. This invention provides a dedicated adaptation method in which the values ​​of transmission parameters within a specified RU can be determined by the triggered transmitting station.

[0135] Figure 8b Another transmission sequence according to an embodiment of the present invention is shown, wherein the RU with an indicator has a width of 20 MHz.

[0136] More precisely, since RU size is counted in terms of the number of frequency modulations, the example illustration shows a 242-frequency modulation RU aligned on a 20MHz channel. It's possible that the RU size corresponds to a multiple of the 20MHz channel (that is, the RU size is set to n). (Maximum bandwidth of 20MHz channel).

[0137] This offers a significant advantage because the HE-SIG-A field typically has a width of 20 MHz. Existing 802.11 standards require the HE-SIG-A field to be replicated on each occupied 20 MHz channel of the channel bandwidth.

[0138] and Figure 8a In contrast to the example shown, RU5 and RU6 now have a 20MHz width, making the full operating band reserved for the TF 210 80MHz.

[0139] Note the difference from the triggering mechanism of the 802.11ax standard; preambles 230, 830, and 831 in the figure are all transmitted on a 20MHz basis, but they are different. The new triggering mechanism according to embodiments of the present invention provides for the use of various preambles in the RU; the preamble can be the conventional pre-HE modulation field 360c (for 230) for HE TB PPDU, but it can also be the pre-HE modulation field 360a (for 830 and 831) for HE SU PPDU.

[0140] Recall that the pre-HE modulation field 360b of the HE MU PPDU can also be used (for 830 and 831), in which only the AID of STA2 is listed in HE-SIG-B 350 of the preamble 830, and only the AID of STA6 is listed in HE-SIG-B 350 of the preamble 831.

[0141] Finally, each STA (STA6 and STA2) uses its own preamble on its different channels (in other words, its own PPDU format in its assigned RU). The main advantage is that these associated stations do not need to synchronize (as with traditional trigger-based stations making MU UL transmissions toward the AP), as long as they meet the TXOP limit (RU length).

[0142] Alternatively, only a portion of the pre-HE (or pre-EHT) modulation field is synchronized. For example, from L-STF to HE-SIG-A ( Figures 3a to 3c The fields are aligned in terms of start time and duration.

[0143] Additionally, the AP does not need to know the P2P transmission characteristics (therefore, it does not provide all triggering parameters, such as MCS). Only the TXOP length (via the RU length attribute) will be helpful for the receiving STA, as they will meet the requirement.

[0144] Preferably, the selected RU location corresponds to the secondary channel.

[0145] The 802.11ax standard also considers a 20MHz-only operating mode for 802.11ax client stations. Through management frames, client stations will be able to notify the 802.11ax AP that they are operating as 20MHz-only client stations. Typically, 20MHz-only stations can only communicate via OFDMA RU within the 20MHz primary channel.

[0146] Embodiments of the present invention support these 20MHz-only client stations by offloading the operating frequency band on one of the secondary 20MHz channels (i.e., the secondary, tertiary, or quaternary 20MHz sub-channels of the 80MHz band) during the authorized TXOP. The allocated RU can be used as a classic 20MHz channel (that is, as a non-OFDMA 20MHz, rather than as a 242-band RU) because the HE SU PPDU format is used in this band.

[0147] This invention provides an embodiment of a novel Fast Session Transport (FST) protocol that allows different transport sessions to be smoothly transferred from one channel to another.

[0148] The new protocol allows devices operating at only 20MHz to benefit from the larger bandwidth offered by the 802.11 standard and avoids limiting their operation on the currently only 20MHz main channel.

[0149] Figure 8c Another transmission sequence according to an embodiment of the present invention is shown, wherein an RU with an indicator can be perceived as a frequency band allocation for a given set of stations.

[0150] As shown in the figure, RU5 is considered the operating band in the SU communication style by the triggered station; the transmission of each frame is separated by SIFS gaps. For example, the pair 830A / 840A corresponds to the data transmission from STA2 to STA4, while the pair 830B / 840B is the acknowledgment transmitted by STA4.

[0151] Since the HE SU PPDU format will be used for all frames transmitted in an RU having a set of indicators according to an embodiment of the invention, several SU protocols can be envisioned (constrained by the TXOP duration, in other words, guaranteed and not exceeding the RU length).

[0152] As already discussed, the PHY preambles 830A-830B-830C preferably have the same frequency width as the correlated data 840A-840B-840C, i.e., a width of 20 MHz. Alternatively, the width of the correlated data 840A-840B-840C can be slightly narrower by reserving an empty 26-frequency modulation RU at any channel edge (as an example, scheduling an empty 26-frequency modulation RU within RU5 near the channel boundary of the main channel, e.g., an RU with AID=2046) to limit interference.

[0153] This could be a case of a “reverse authorization” protocol, where the triggered source 802.11 station corresponds to the reverse (RD) initiator, and the triggered destination 802.11 station is the reverse (RD) responder.

[0154] The RD initiator that grants the RDG transmission opportunity should ensure that the remaining RU length is not bypassed. Otherwise, the final PPDU will be padded with padding (dashed lines within the 840C MAC frame).

[0155] As a result, this invention provides a mechanism for allocating frequencies / time slots for conventional SU communication.

[0156] Embodiments of the present invention offer several advantages because they leverage the combined benefits of multi-user and single-user operation, which enhances the efficiency of the global cell. The proposed scheme is more efficient than SU media access schemes (previous EDCA direct link protocols, RDP protocols, etc.) because P2P communication is triggered by the AP (avoiding media access conflicts). This scheme is backward compatible with classic MU UL operation because the AP can still simultaneously receive classic OFDMA uplink RUs from other STAs.

[0157] Figure 8d Another transmission sequence according to an embodiment of the present invention is shown, wherein the RU with the indicator set can be considered to be a frequency band allocation belonging to a set of stations of another BSS (that is, a BSS managed by an AP different from the AP that transmits trigger frame 210).

[0158] The embodiments specify that several PPDU formats can be used for frames of other BSSs transmitted in an RU having an indicator set according to the present invention.

[0159] As an example, trigger frame 840D can be sent by the triggered AP (second AP) in MU or SU format on a reserved RU. This frame is used to trigger stations in the second BSS managed by the second AP (e.g., AP2). Therefore, stations in BSS2 can detect the second TF and transmit their trigger frames 840E. The RU allocation provided by trigger frame 840D from AP2 should ensure that the RU triggered by the second TF is included among the RUs authorized by AP1.

[0160] As another example, the MU downlink frame (840F) can also be transmitted within the RU authorized by AP1, where AP2 sends several AMPDUs for multiple users of its BSS (BSS2).

[0161] The PHY preamble 830D-830E-830F can have the same frequency width as the correlated data 840D-840E-840F, i.e., a width of 20 MHz. Alternatively, the width of the correlated data 840D-840E-840F can be slightly narrower. For example, an empty 26-frequency modulated RU (e.g., an RU with AID=2046) can be located at any channel edge to limit interference. Regarding Figure 8d RUs with the attached reference numeral 850 are not used (empty) because they are close to the main channel.

[0162] Therefore, embodiments of the present invention provide that AP2 uses its own transmission parameters within the RU authorized by AP1, except that the bandwidth of the PPDU should be adapted to the RU width of AP1. As shown in the figure, the preferred embodiment considers a 20MHz width of the RU authorized by AP1.

[0163] One advantage of this scheme is that the first AP (AP1) provides coordination for several second APs, each operating in a different 20MHz RU, thus avoiding interference between the second APs.

[0164] Figure 10 An embodiment of the invention is illustrated using a flowchart, which is prepared to configure itself as a receiver of TB PPDU transmissions from a triggered STA as a result of a received trigger frame.

[0165] More specifically, the triggered STA can be the source STA in the context of the DiL transmission, while the destination STA will be the receiver of the DiL transmission.

[0166] In the context of inter-AP coordination, the triggered STA is the second AP (e.g., AP2) listed in the RU allocation of the trigger frame received from the triggering AP (e.g., AP1). The destination STA can be any non-AP station belonging to the second BSS (e.g., any non-AP STA associated with AP2).

[0167] In step 1001, the destination STA receives a trigger frame that assigns a MU RU (Multi-Use RU) to the triggered STA for data transmission. The RU can be a scheduled RU or a random RU for the triggered STA.

[0168] It can be noted that TF does not include destination STA as the recipient of TF (the destination is not visible in the recipient address of TF and is also not visible in the RU allocation list).

[0169] Optionally, test 1002 is performed to determine whether the received TF is related to the triggered STA, i.e., whether the STA is related to the triggered STA.

[0170] In the case of a DiL transmission, the triggered (destination) STA can determine whether the TF originated from its local AP; the TA field is set to the BSSID value corresponding to the AP associated with the STA (or, in the case of multiple BSSs supported, at least the BSSID associated with the same physical AP). If the TF originated from the local AP, the destination STA further searches for its AID or DiL session AID within the RU allocation field to continue operation. If the destination STA finds its AID or is followed by the session AID, test 1002 is considered positive, and the algorithm continues in step 1003.

[0171] Even if the transmission is not DiL, the STA may not directly ignore the TF from the remote AP in step 1002 because the STA must first determine whether it is the destination STA. As a result, the traditional behavior of setting the NAV in the reception to the TF must be modified.

[0172] The implementation can envision a new trigger type for this TF 700 (the trigger type subfield in the public information field identifies the trigger frame variant and specifies a new value for AP coordination), such that the STA receiving the TF with the new TF variant value will analyze each user information element.

[0173] Other means can be envisioned to allow analysis of TFs received from remote APs near the STA. As an example, the STA may have previously determined that its associated AP has notified it of supporting AP coordination capabilities by including a list of capabilities advertised in management (e.g., beacon or probe response) frames sent by the AP.

[0174] If the receiving STA already finds its AP in the list of triggered stations, then the receiving STA considers itself the destination STA. As already discussed, as an example, the AID12 field of the user information field can transmit the BSSID corresponding to the AP it is associated with.

[0175] The STA that is stated as the destination STA (test 1002 is positive) will continue the algorithm in step 1003.

[0176] Step 1003 is similar to step 502, wherein the destination STA retrieves from the (transmitting TF) AP an indication of whether the triggered STA (e.g., a triggered non-AP STA for DiL, or a triggered AP for AP coordination) is allowed to select a value. This indication is preferably retrieved from a field in the trigger frame.

[0177] If the indicator is present and specifies that the triggered station determines the transmission parameters, the destination station is thus prepared to receive the data itself in the DiL RU; the parameters used will be determined by analyzing the PHY preamble when receiving the PPDU, as is done for single-user mode. The PHY preamble is expected to have the same width as the associated data.

[0178] If no indicator is present, or if the indicator specifies that the transmission parameters to be considered are the transmission parameters of the trigger frame, the destination station will then prepare to receive the data in the DiL RU in the usual manner; the PHY preamble will have a width of 20 MHz, and then the relevant data will be received on the RU.

[0179] According to the passage Figure 8c and 8d In the disclosed preferred embodiment, the RU width is one or more of a continuous 20MHz frequency band.

[0180] Therefore, the destination STA must switch its primary channel to the temporary RU channel as indicated in the trigger frame. If the RU is greater than 20MHz, then only one 20MHz channel is the primary channel, and the other channels are secondary channels.

[0181] Next, the non-AP destination STA configures its physical PHY layer in the receive state to receive PPDU frames (1004) on a resource element or a 20MHz channel containing a resource element (in response to a trigger frame).

[0182] In the context of AP coordination, the coordinated AP (second AP) and its associated STA (destination STA) switch their primary channel to the temporary RU channel as indicated in the trigger frame. After the coordinated OFDMA duration (ending with the TXOP authorized by the first AP), the coordinated AP and its associated STA switch back to their original primary channel.

[0183] Figure 9a A communication device 900 (not AP stations 101-107 or access point 110) configured to implement at least one embodiment of the present invention is schematically shown. The communication device 900 may preferably be a device such as a microcomputer, workstation, or lightweight portable device. The communication device 900 includes a communication bus 913, to which the following items are preferably connected:

[0184] The central processing unit 901, such as a processor, is represented as a CPU.

[0185] Memory 903 is used to store executable code of a method or steps of a method according to an embodiment of the present invention, and registers adapted to record variables and parameters required to implement the method; and

[0186] At least one communication interface 902 is connected to a wireless communication network (e.g., a communication network according to one of the IEEE 802.11 standard families) via a transmit and receive antenna 904.

[0187] Preferably, the communication bus provides communication and interoperability between various elements included in or connected to the communication device 900. The representation of the bus is not limiting, and in particular, the central processing unit is operable to transmit instructions directly or by means of another element of the communication device 900 to any element of the communication device 900.

[0188] The executable code can be stored in memory, which can be read-only, a hard disk, or a removable digital medium, such as a disk. According to an alternative variation, the executable code of the program can be received via interface 902 through a communication network and stored in the memory of the communication device 900 before execution.

[0189] In one embodiment, the apparatus is a programmable device that uses software to implement embodiments of the invention. However, alternatively, embodiments of the invention may be implemented wholly or partially in hardware (e.g., in the form of an application-specific integrated circuit or ASIC).

[0190] Figure 9b This is a block diagram schematically illustrating the architecture of a communication device 900 (AP 110 or one of stations 101-107) suitable for at least partially implementing the present invention. As shown, device 900 includes a physical (PHY) layer block 923, a MAC layer block 922, and an application layer block 921.

[0191] PHY layer block 923 (here, the 802.11 standardized PHY layer) has the task of formatting, modulating, or demodulating any 20MHz channel or composite channel, and thus transmitting or receiving frames, such as 802.11 frames, on the radio medium 100 used, for example, the medium access trigger frame TF 510 for reserving transmission time slots. Figure 7 ), MAC data and management frames based on a 20MHz width for interaction with conventional 802.11 stations, and OFDMA type MAC data frames relative to the radio medium with a smaller width (typically 2 or 5MHz) than the conventional 20MHz.

[0192] The MAC layer block or controller 922 preferably includes a MAC 802.11 layer 824 that implements conventional 802.11 ax MAC operations, and an additional block 925 for at least partially performing the present invention. The MAC layer block 922 may optionally be implemented in software, which is loaded into RAM 903 and executed by CPU 901.

[0193] Preferably, the supplementary block 925 (referred to as the trigger TX parameter management module, used to select transmission parameters applied to transmissions following the medium access trigger frame via OFDMA resource units (sub-channels)) implements a portion of the embodiments of the present invention (from the perspective of the slave station or from the perspective of the AP).

[0194] For example, and not exhaustively, operations at a station (AP or non-AP) may include: at the AP, generating and sending a trigger frame to allocate a RU for DiL or UL transmission, wherein the TF indicates whether the transmission parameters for sending data on the RU are set by the AP or by the source station. Operations at a non-AP station may include configuring the PHY for transmission / reception on the DiL / UL RU according to provided instructions, that is, when provided, the transmitted PPDU frame has an HE SU PPDU (otherwise following the HE TB PPDU format typically used for triggering operations).

[0195] According to an embodiment of the present invention, the MAC 802.11 layer 924 and the trigger TX parameter management module 925 interact with each other to accurately handle communication on OFDMA RUs addressed to multiple stations.

[0196] At the top of the diagram, application layer block 921 runs the application used to generate and receive data packets (e.g., data packets such as video streams). Application layer block 921 represents all stack layers above the MAC layer, as standardized by ISO.

[0197] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to these specific embodiments, and modifications within the scope of the present invention will be apparent to those skilled in the art.

[0198] Specifically, where appropriate, the different HE frame formats described in different embodiments can be replaced by EHT frame formats.

[0199] Many further modifications and variations will arise for those skilled in the art when referring to the foregoing illustrative embodiments. The foregoing illustrative embodiments are given by way of example only and are not intended to limit the scope of the invention, which is defined only by the appended claims. In particular, different features from different embodiments may be interchanged where appropriate.

[0200] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple elements. The mere fact that different features are recited in mutually different dependent claims does not indicate that combinations of these features cannot be used advantageously.

Claims

1. A method for wireless communication, comprising at a station (STA): The access point (AP) receives a trigger frame (TF), which allocates a resource unit (RU) to the station for transmitting physical layer protocol data units (PPDUs). Each RU corresponds to a frequency bandwidth occupying one or more 20MHz channels. According to the instructions provided by the AP in the TF, the PPDU is transmitted in the allocated RU according to either a trigger-based PPDU format or a non-trigger-based PPDU format. The PPDU preamble includes an L-short training field (L-STF) and a first short training field (First STF), wherein the duration of the trigger-based PPDU format First STF is twice the duration of the non-trigger-based PPDU format First STF field.

2. The method according to claim 1, wherein, The preamble of the PPDU is transmitted on each of the 20MHz channels in one or more of the 20MHz channels of the RU.

3. The method according to claim 1, wherein, The indication provided in the TF indicates that the transmission parameters are set by the STA for transmitting non-trigger-based PPDUs and by the AP for transmitting trigger-based PPDUs.

4. The method according to claim 1, wherein, The non-trigger-based PPDU format is the single-user PPDU format, i.e., the SU PPDU format.

5. The method according to claim 4, wherein, The PPDU transmitted in the direct link within the allocated RU uses the SU PPDU format.

6. The method according to claim 1, wherein, The duration of the first STF in the trigger-based PPDU format is 8µs, and the duration of the first STF in the non-trigger-based PPDU format is 4µs.

7. A method for wireless communication, comprising at an access point (AP): The transmission trigger frame (TF) allocates resource units (RUs) to the station (STA) for transmitting physical layer protocol data units (PPDUs). Each RU corresponds to a frequency bandwidth occupying one or more 20MHz channels. Wherein, the TF includes an indication, and the STA transmits a PPDU in the allocated RU in either a trigger-based PPDU format or a non-trigger-based PPDU format according to the indication, and Wherein, the duration of the L-Short Training Field (L-STF) and the First Short Training Field (First STF) in the preamble of the PPDU based on the triggered PPDU format is twice the duration of the First STF in the non-triggered PPDU format.

8. A wireless communication device, comprising: The receiving unit is configured to receive a trigger frame (TF) from the access point (AP), the TF allocating a resource unit (RU) to the station (STA) for transmitting physical layer protocol data units (PPDUs), wherein the RU corresponds to a frequency bandwidth occupying one or more 20MHz channels. as well as A transmitting unit, configured to transmit the PPDU in the allocated RU according to a trigger-based PPDU format or a non-trigger-based PPDU format, based on an instruction provided by the AP in the TF. The PPDU preamble includes an L-short training field (L-STF) and a first short training field (First STF), wherein the duration of the trigger-based PPDU format First STF is twice the duration of the non-trigger-based PPDU format First STF field.

9. An access point device, comprising: The transmitting unit is configured to transmit a trigger frame (TF), which allocates resource units (RUs) to stations (STAs) for transmitting physical layer protocol data units (PPDUs). Each RU corresponds to a frequency bandwidth occupying one or more 20MHz channels. Wherein, the TF includes an indication, and the STA transmits a PPDU in the allocated RU in either a trigger-based PPDU format or a non-trigger-based PPDU format according to the indication, and The PPDU preamble includes an L-short training field (L-STF) and a first short training field (First STF), and the duration of the First STF in the preamble of the PPDU based on the trigger-based PPDU format is twice the duration of the First STF in the PPDU not based on the trigger-based PPDU format.

10. A program executed by one or more processors of a wireless communication device, the program causing the wireless communication device to perform operations stored in one or more memories, the operations including: The access point (AP) receives a trigger frame (TF), which allocates resource units (RUs) to stations (STAs) for transmitting physical layer protocol data units (PPDUs). Each RU corresponds to a frequency bandwidth occupying one or more 20MHz channels. According to the instructions provided by the AP in the TF, the PPDU is transmitted in the allocated RU according to either a trigger-based PPDU format or a non-trigger-based PPDU format. The PPDU preamble includes an L-short training field (L-STF) and a first short training field (First STF), wherein the duration of the trigger-based PPDU format First STF is twice the duration of the non-trigger-based PPDU format First STF field.

11. A program executed by one or more processors of a wireless communication device, the program causing the wireless communication device to perform operations stored in one or more memories, the operations including: The transmission trigger frame (TF) allocates resource units (RUs) to the station (STA) for transmitting physical layer protocol data units (PPDUs). Each RU corresponds to a frequency bandwidth occupying one or more 20MHz channels. Wherein, the TF includes an indication, and the STA transmits a PPDU in the allocated RU in either a trigger-based PPDU format or a non-trigger-based PPDU format according to the indication, and The PPDU preamble includes an L-short training field (L-STF) and a first short training field (First STF), and the duration of the First STF in the preamble of the PPDU based on the trigger-based PPDU format is twice the duration of the First STF in the PPDU not based on the trigger-based PPDU format.

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