Apparatus and method for accessing channel

Abstract

An apparatus for accessing a channel in a wireless local area network is provided. The device simultaneously monitors the first primary channel and the second primary channel. When a network allocation vector (NAV) of the first primary channel is set but the second primary channel is idle, the device switches from the first primary channel to the second primary channel to initiate a physical layer protocol data unit (PPDU) transmission on the second primary channel.

Description

Technical Field

[0001] The present disclosure relates to wireless local area networks (WLANs), and more particularly, to a channel access mechanism in a WLAN. Background Art

[0002] A wireless local area network (WLAN) may be formed by one or more access points (APs) that provide a shared wireless communication medium for use by multiple client devices, also referred to as stations (STAs).

[0003] Orthogonal Frequency Division Multiple Access (OFDMA) is a multiple access scheme in which different subsets of subcarriers are assigned to different users and which allows simultaneous data transmission to or from one or more users.

[0004] The physical layer protocol data unit (PPDU) is a data unit (or data packet) used to carry various information in a WLAN. In OFDMA, users are assigned different subcarrier subsets that can change from one PPDU to the next. Using OFDMA, the AP can assign different RUs to STAs. The AP can transmit PPDUs of various formats to multiple STAs simultaneously. Summary of the invention Technical issues

[0005] The present disclosure provides a method for accessing a channel in a wireless local area network.

[0006] The present disclosure also provides a device for accessing a channel in a wireless local area network.

[0007] Solutions to the Problem In one aspect, a method for accessing a channel in a wireless local area network is provided. The method is performed by a station, and includes: receiving a frame including information about a first primary channel and a second primary channel; monitoring the first primary channel and the second primary channel simultaneously; and when a network allocation vector (NAV) of the first primary channel is set but the second primary channel is idle, switching from the first primary channel to the second primary channel to initiate physical layer protocol data unit (PPDU) transmission on the second primary channel.

[0008] On the other hand, a device for accessing a channel in a wireless local area network is provided. The device includes a processor, and a memory operably coupled to the processor and configured to store instructions, which, when executed by the processor, cause the device to perform functions. The functions include: receiving a frame containing information about a first primary channel and a second primary channel; monitoring the first primary channel and the second primary channel simultaneously; and when a network allocation vector (NAV) of the first primary channel is set but the second primary channel is idle, switching from the first primary channel to the second primary channel to initiate physical layer protocol data unit (PPDU) transmission on the second primary channel.

[0009] Beneficial effects of the present invention As new WLAN communication protocols enable enhanced features, a non-primary channel access mechanism is provided to support signaling regarding features and resource allocation. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A block diagram of an example wireless communication network is shown.

[0011] Figure 2 A block diagram of an example wireless communication device is shown.

[0012] Figure 3 and Figure 4 Various examples of PPDUs that may be used for wireless communications between an AP and multiple STAs are shown.

[0013] Figure 5 An example of a wireless channel including multiple sub-channels is shown.

[0014] Figure 6 An example of PPDU transmission is shown.

[0015] Figure 7 An example of UL MU transmission is shown.

[0016] Figure 8 A non-primary channel access mechanism according to an embodiment of the present invention is shown.

[0017] Fig. 9 An example of a SERVICE field that supports a non-primary channel access mechanism is shown.

[0018] Fig.10 A non-primary channel access mechanism according to an embodiment of the present invention is shown.

[0019] Fig.11 A non-primary channel access mechanism according to another embodiment of the present invention is shown.

[0020] Fig.12 A non-primary channel access mechanism according to yet another embodiment of the present invention is shown.

[0021] Fig.13 A non-primary channel access mechanism according to yet another embodiment of the present invention is shown.

[0022] Fig.14 A non-primary channel access mechanism according to yet another embodiment of the present invention is shown.

[0023] Fig.15 A non-primary channel access mechanism applied to a peer-to-peer application according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0024] The following description relates to certain embodiments for the purpose of describing the innovative aspects of the present disclosure. However, it will be readily appreciated by those skilled in the art that the teachings herein can be applied in a variety of different ways. The described embodiments may be implemented in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals according to one or more of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, IEEE 802.15 standards, Bluetooth® standards defined by the Bluetooth Special Interest Group (SIG), or Long Term Evolution (LTE), 3G, 4G, or 5G (New Radio (NR)) standards promulgated by the Third Generation Partnership Project (3GPP). The described implementations may be implemented in any device, system, or network capable of transmitting and receiving RF signals according to one or more of the following technologies or methods: code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), single user (SU) multiple input multiple output (MIMO), and multi-user (MU) MIMO. The described implementations may also be implemented using other wireless communication protocols or RF signals suitable for one or more of a wireless personal area network (WPAN), a wireless local area network (WLAN), a wireless wide area network (WWAN), or an Internet of Things (IOT) network.

[0025] OFDMA is a multiple access scheme based on OFDM in which different subcarrier subsets are assigned to different users and the scheme allows simultaneous data transmission to or from one or more users. In OFDMA, users are assigned different subcarrier subsets that can change from one PPDU to the next. Similar to OFDM, OFDMA employs multiple subcarriers, but the subcarriers are divided into groups, where each group is called a resource unit (RU).

[0026] A physical layer protocol data unit (PPDU) may span one or more subchannels and may include a preamble portion and a data portion. Signaling refers to a control field or information in the preamble portion that a wireless communication device may use to interpret another field or portion of the preamble portion or data portion of the PPDU. A wireless channel may be formed by multiple subchannels. A subchannel may include a group of subcarriers. Portions of the wireless channel bandwidth may be divided or grouped to form different resource units (RUs). A RU may be a unit for resource allocation and may include one or more subcarriers. In addition, the preamble portion of the PPDU may include signaling to indicate which RUs are allocated to different devices. Other types of signaling include indicators about which subchannels include further signaling or which subchannels may be punctured. Several PPDU formats (and related structures) are defined for current wireless communication protocols. Since new wireless communication protocols support enhanced features, new preamble designs are required to support signaling about features and resource allocation. In addition, it is desirable to define a new preamble signaling protocol that can support future wireless communication protocols.

[0027] Figure 1 A block diagram of an example wireless communication network is shown.

[0028] According to some aspects, the wireless communication network 10 may be an example of a wireless local area network (WLAN), such as a Wi-Fi network (hereinafter referred to as WLAN 10). For example, the WLAN 10 may be a network that implements at least one of the IEEE 802.11 series of wireless communication protocol standards (such as the standards defined by the IEEE 802.11-2016 specification or its revised version, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be). The WLAN 10 may include many wireless communication devices, such as an access point (AP) 11 and a plurality of stations (STAs) 12. Although only one AP 11 is shown, the WLAN network 10 may also include a plurality of APs.

[0029] Each STA 12 may also be referred to as a mobile station (MS), a mobile device, a mobile handset, a wireless handset, an access terminal (AT), a user equipment (UE), a subscriber station (SS) or a subscriber unit, etc. The STA 12 may represent a variety of devices, such as mobile phones, personal digital assistants (PDAs), other handheld devices, netbooks, notebook computers, tablet computers, laptop computers, display devices (e.g., televisions, computer monitors, navigation systems, etc.), music or other audio or stereo equipment, remote control devices (“remote controls”), printers, kitchen or other home appliances, key fobs (e.g., for passive keyless entry and start (PKES) systems), etc.

[0030] A single AP 11 and an associated group of STAs 12 may be referred to as a basic service set (BSS), which is managed by the corresponding AP 11. The BSS may be identified to a user by a service set identifier (SSID), and may be identified to other devices by a basic service set identifier (BSSID), which may be a medium access control (MAC) address of the AP 11. The AP 11 periodically broadcasts a beacon frame ("beacon") including the BSSID to enable any STA 12 within the wireless range of the AP 11 to "associate" or re-associate with the AP 11 to establish a corresponding communication link (hereinafter also referred to as a "Wi-Fi link") with the AP 11 or to maintain a communication link with the AP 11. For example, the beacon may include an identification of a primary channel used by the corresponding AP 11 and a timing synchronization function for establishing or maintaining timing synchronization with the AP 11. The AP 11 may provide access to external networks for various STAs 12 in the WLAN via corresponding communication links.

[0031] To establish a communication link with the AP 11, each STA 12 is configured to perform a passive or active scanning operation ("scanning") on frequency channels in one or more frequency bands (e.g., the 2.4 GHz, 5 GHz, 6 GHz, or 60 GHz bands). To perform a passive scan, the STA 12 listens for beacons, which are transmitted by each AP 11 at periodic time intervals called target beacon transmission times (TBTTs) (measured in time units (TUs), one TU may be equal to 1024 microseconds (μs)). To perform an active scan, the STA 12 generates and sequentially transmits a probe request on each channel to be scanned, and listens for probe responses from the AP 11. Each STA 12 may be configured to identify or select an AP 11 to associate with based on the scanning information obtained through the passive or active scan, and to perform an authentication and association operation to establish a communication link with the selected AP 11. The AP 11 assigns an association identifier (AID) to the STA 12 at the end of the association operation, and the AP 11 uses the identifier to track the STA 104.

[0032] In some cases, STA 12 can form a network without AP 11 or other devices other than STA. An example of such a network is a self-organizing network (or wireless self-organizing network). A self-organizing network can be alternatively referred to as a mesh network or a peer-to-peer (P2P) network. In some cases, a self-organizing network can be implemented within a larger wireless network such as WLAN 10. In such an implementation, although STA 12 can communicate with each other through AP 11 using a communication link, STA 12 can also communicate directly with each other via a direct wireless link. In addition, two STAs 12 can communicate via a direct communication link, regardless of whether the two STAs 12 are associated with and served by the same AP 11. In such a self-organizing system, one or more STAs 12 can assume the role played by AP 11 in the BSS. Such STAs can be called group owners (GOs) and can coordinate transmissions within the self-organizing network.

[0033] The AP 11 and the STA 12 may operate and communicate (via respective communication links) according to the IEEE 802.11 series of wireless communication protocol standards (e.g., standards defined by the IEEE 802.11-2016 specification or its revised versions, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be). These standards define WLAN radio and baseband protocols for the PHY and medium access control (MAC) layers. The AP 11 and the STA 12 transmit and receive wireless communications (hereinafter also referred to as "Wi-Fi communications") with each other in the form of PPDUs. The AP 11 and the STA 12 in the WLAN 10 may transmit the PPDUs through an unlicensed spectrum, which may be a portion of a spectrum including frequency bands traditionally used by Wi-Fi technology, such as the 2.4 GHz band, the 5 GHz band, the 60 GHz band, the 3.6 GHz band, and the 900 MHz band. Some implementations of the AP 11 and STA 12 described herein may also communicate in other frequency bands, such as the 6 GHz band, which may support both licensed and unlicensed communications. The AP 11 and STA 12 may also be configured to communicate on other frequency bands, such as shared licensed frequency bands, where multiple operators may have licenses to operate in the same or overlapping frequency bands.

[0034] Each frequency band may include multiple channels (which may be used as subchannels of a larger bandwidth channel). For example, PPDUs compliant with the IEEE 802.11n, 802.11ac, and 802.11ax standards may be transmitted on the 2.4 and 5 GHz frequency bands, each of which is divided into multiple 20 MHz channels. Therefore, these PPDUs are transmitted over a physical channel with a minimum bandwidth of 20 MHz, but may form larger channels through channel bonding. For example, a PPDU may be transmitted on a physical channel with a bandwidth of 40 MHz, 80 MHz, 160, or 320 MHz by bonding multiple 20 MHz channels (which may be referred to as subchannels) together.

[0035] Each PPDU is a composite structure that includes a PHY preamble and a payload in the form of a PHY service data unit (PSDU). The receiving device can use the information provided in the preamble to decode subsequent data in the PSDU. In the case where the PPDU is transmitted over a bonded channel, the preamble field can be replicated and transmitted in each of multiple component channels. The PHY preamble may include a first part (or "legacy preamble") and a second part (or "non-legacy preamble"). The first part can be used for purposes such as packet detection, automatic gain control, and channel estimation. The first part can also generally be used to maintain compatibility with legacy devices as well as non-legacy devices. The format, encoding, and information provided by the second part of the preamble are based on the specific IEEE 802.11 protocol used to transmit the payload.

[0036] Uplink (UL) means that a signal (or message or PPDU) is transmitted by a STA to an AP, and downlink (DL) means that a signal (or message or PPDU) is transmitted by an AP to one or more STAs.

[0037] Figure 2 A block diagram of an example wireless communication device is shown.

[0038] In some implementations, the wireless communication device 50 may be an example of a device for a STA, such as the one described above with reference to Figure 1 In some implementations, the wireless communication device 50 may be an example of a device for an AP, such as the one described above with reference to Figure 1 The wireless communication device 50 is capable of transmitting (or outputting for transmission) and receiving wireless communications (e.g., in the form of wireless data packets). For example, the wireless communication device may be configured to transmit and receive data packets in the form of PPDUs and / or medium access control (MAC) protocol data units (MPDUs) that comply with IEEE 802.11 wireless communication protocol standards (such as those defined by the IEEE 802.11-2016 specification or its revisions, including but not limited to 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be).

[0039] The wireless communication device 800 may be or may include a chip, a system on chip (SoC), a chipset, a package, or a device including one or more processors 51. The processor 51 may include an intelligent hardware block or device, such as, for example, a processing core, a processing block, a central processing unit (CPU), a microprocessor, a microcontroller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD) (e.g., a field programmable gate array (FPGA)), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor 51 processes information received through the transceiver 53 and processes information to be output through the transceiver 53 through a wireless medium. For example, the processor 806 may implement a physical (PHY) layer and / or a MAC layer, which is configured to perform various operations related to the generation and transmission of PPDUs, MPDUs, frames, or data packets.

[0040] The memory 52 may include a tangible storage medium, such as a random access memory (RAM) or a read-only memory (ROM), or a combination thereof. The memory 808 may also store non-transitory processor or computer executable software code containing instructions that, when executed by the processor 51, cause the wireless communication device 50 to perform various operations of wireless communication described herein, including the generation, transmission, reception, and interpretation of PPDUs, MPDUs, frames, or data packets. For example, various functions of the components disclosed herein, or various blocks or steps of the methods, operations, processes, or algorithms disclosed herein, may be implemented as one or more modules of one or more computer programs.

[0041] The transceiver 53 typically includes at least one radio frequency (RF) transmitter (or "transmitter chain") for transmitting radio signals and at least one RF receiver (or "receiver chain") for receiving radio signals. For example, the RF transmitter and receiver may include various DSP circuits, including at least one power amplifier (PA) and at least one low noise amplifier (LNA), respectively. The RF transmitter and receiver may in turn be coupled to one or more antennas. For example, in some implementations, the wireless communication device 50 may include multiple transmit antennas and multiple receive antennas or be coupled to multiple transmit antennas (each transmit antenna having a corresponding transmit chain) and multiple receive antennas (each receive antenna having a corresponding receive chain).

[0042] Figure 3 and Figure 4 Various examples of PPDUs that may be used for wireless communications between an AP and multiple STAs are shown.

[0043] The PPDU may include a preamble portion and a data portion. Figure 3 to Figure 4The "data" in the 'data' part refers to a data part including one or more PSDUs and appearing after the preamble part. The data part may be referred to as a payload.

[0044] The non-high throughput (non-HT) PPDU supporting IEEE 802.11a / g includes the legacy short training field (L-STF), the legacy long training field (L-LTF), the legacy signal (L-SIG) and the data part. The L-SIG can be called a non-HT signal. The high throughput (HT) PPDU supporting IEEE802.11n includes L-STF, HT-SIG, HT-STF, HT-LTF and the data part. The very high throughput (VHT) PPDU supporting IEEE802.11ac includes L-STF, L-SIG, VHT-SIG-A, VHT-STF, VHT-LTF, VHT-SIG-B and the data part.

[0045] A High Efficiency (HE) PPDU supporting IEEE 802.11ax may include a HE Single User (SU) PPDU for SU transmission and a HE Multi User (MU) PPDU for MU transmission. An Extremely High Throughput (EHT) PPDU supporting IEEE 802.11be may include an EHT MU PPDU for MU transmission and an EHT Trigger (TB) based PPDU.

[0046] The preamble part of the PPDU may include a first part (or "legacy preamble") and a second part (or "non-legacy preamble"). The first part may include L-STF, L-LTF, and L-SIG. The second part may include at least one of HT-SIG, HT-STF, HT-LTF, VHT-SIG-A, VHT-STF, VHT-LTF, VHT-SIG-B, RL-SIG, HE-SIG-A, HE-STF, HE-LTF, HE-SIG-B, EHT-SIG, EHT-STF, EHT-LTF, and U-SIG.

[0047] L-STF can be used for frame detection, automatic gain control (AGC), diversity detection, and coarse frequency / time synchronization. L-LTF can be used for fine frequency / time synchronization and channel estimation. L-SIG may include information indicating the total length of the corresponding PPDU (or information indicating the transmission time of the PSDU).

[0048] The VHT-SIG-A field carries information required to interpret the VHT PPDU. The VHT-STF field is used to improve automatic gain control estimation in MIMO. The VHT-LTF field provides a means for the receiver to estimate the MIMO channel between the constellation mapper output set and the receive chain. The VHT-SIG-B field may be used for MU transmission and may contain signaling information that may be used by the STA to decode the data received in the DATA field, including, for example, modulation and coding scheme (MCS) and beamforming information.

[0049] The Repeated Legacy (RL)-SIG field in the HE PPDU and EHT PPDU is a repetition of the L-SIG field and is used to distinguish the HE PPDU and EHT PPDU from the non-HT PPDU, HT PPDU, and VHT PPDU.

[0050] HE-SIG-A carries the information required to interpret the HE PPDU. HE-SIG-A may indicate the location and length of HE-SIG-B, available channel bandwidth, etc. HE-SIG-B may carry STA-specific scheduling information, such as, for example, the MCS value of each user and the RU allocation information of each user. In the context of DL MU-OFDMA, such information enables the corresponding STA to identify and decode the corresponding RU in the associated data field.

[0051] VHT-STF, HE-STF or EHT-STF can be used to improve AGC estimation in MIMO transmission. VHT-LTF, HE-LTF or EHT-LTF can be used to estimate the MIMO channel.

[0052] The Universal Signaling Field (U-SIG) field of the EHT PPDU carries information required to interpret the EHT PPDU. The U-SIG may include version-independent fields and version-related fields. The version-independent field may include a version identifier, a PPDU bandwidth, an indication of whether the PPDU is a UL or DL ​​PPDU, a BSS color identifying the BSS, and at least one of a transmission opportunity (TXOP). The PPDU bandwidth in the version-independent field indicates the transmission bandwidth of the PPDU, for example, 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 320 MHz. The version identifier in the version-independent field may indicate the version (and associated format) of the version-related fields. The PPDU format may determine which other indicators are included in the version-related fields in addition to the version identifier. In some implementations, if the PPDU format indicates that the PPDU is an EHT TB PPDU, the EHT-SIG may be omitted, such as Figure 4The EHT TB PPDU is shown in the U-SIG. The version-related fields of the U-SIG may include puncturing channel information and EHT-SIG MCS. The EHT-SIG MCS may indicate the MCS used to modulate the EHT-SIG. The PPDU bandwidth and puncturing channel information may be collectively referred to as frequency occupancy indication. The frequency occupancy indication may allow WLAN devices on the wireless channel to determine the utilization of various parts of the wireless channel. For example, the frequency occupancy information may be used to indicate the puncturing of certain sub-channels.

[0053] The EHT-SIG field provides additional signaling to the U-SIG field so that the STA interprets the EHT MU PPDU. The EHT-SIG may carry STA-specific scheduling information, such as, for example, the MCS value for each user and the RU allocation information for each user. The EHT-SIG includes a common field and at least one STA-specific field ("user-specific field"). The common field may indicate the RU distribution to multiple STAs, indicate the RU allocation in the frequency domain, indicate which RUs are allocated to MU-MIMO transmission and which RUs correspond to MU-OFDMA transmission, and the number of users in the allocation. The user-specific field is allocated to a specific STA 104 and may be used to schedule a specific RU and indicate the scheduling to other WLAN devices.

[0054] The EHT-SIG field of a 20 MHz EHT MU PPDU contains one EHT-SIG content channel. For OFDMA transmissions to multiple users and non-OFDMA transmissions, the EHT-SIG field of a 40 MHz or 80 MHz EHT MU PPDU contains two EHT-SIG content channels. For OFDMA transmissions to multiple users and non-OFDMA transmissions, the EHT-SIG field of a 160 MHz or wider MU PPDU contains two EHT-SIG content channels per 80 MHz. When the EHT MU PPDU bandwidth for OFDMA transmissions exceeds 80 MHz, each 80 MHz of the EHT-SIG content channel is allowed to carry different information. The EHT-SIG field of an EHT MU PPDU sent to a single user and the EHT-SIG field of an EHT Sounding NDP contains one EHT-SIG content channel, which is repeated in each non-punctured 20 MHz when the EHT PPDU is equal to or wider than 40 MHz.

[0055] For OFDMA transmission, the common fields of the EHT-SIG content channel contain information about resource unit allocations, such as the RU allocation to be used in the EHT modulation field of the PPDU, the RUs allocated for MU-MIMO, and the number of users in the MU-MIMO allocation. In non-OFDMA transmissions, the common fields of the EHT-SIG content channel do not contain RU allocations.

[0056] The user specific fields in the EHT-SIG content channel contain information for all users in the PPDU on how to decode their payloads.

[0057] A device receiving a PPDU may initially begin or continue its determination of the wireless communication protocol version used to transmit the PPDU based on the presence of the RL-SIG and the modulation scheme used to modulate the symbols in the U-SIG (or HE-SIG-A). In some implementations, the receiving device may initially determine that the wireless communication protocol used to transmit the PPDU is HE or higher based on the presence of the RL-SIG (i.e., determining that the first symbol of the second portion of the preamble is the same as the L-SIG) and the determination that both the first symbol and the second symbol following the RL-SIG are modulated according to the BPSK modulation scheme.

[0058] The technology in this specification is not limited to Figure 3 to Figure 4 The PPDU format is shown in FIG, but these concepts may be applicable to any PPDU that conforms to a version of the IEEE 802.11 wireless communication protocol.

[0059] Figure 5 An example of a wireless channel including multiple sub-channels is shown.

[0060] A channel map for a frequency band (e.g., 2.5 GHz, 5 GHz, 6 GHz bands, etc.) may define multiple subchannels. Each subchannel may have a uniform channel width W = 20 MHz, but the technology in this specification is not limited to 20 MHz. The channel width W may be less than or greater than 20 MHz.

[0061] Some WLAN devices are capable of transmitting at higher bandwidths using a radio channel composed of multiple subchannels. When a WLAN device is capable of transmitting in a BSS operating channel width of 80 MHz, a set of four subchannels (primary 20 MHz channel, secondary 20 MHz channel, and secondary 40 MHz channel) is used. Figure 5 In the present invention, the BSS operating channels have bandwidths of 20 MHz, 40 MHz, 80 MHz, and 160 MHz. Although depicted as contiguous subchannels in the channel diagram, in some implementations, the BSS operating channels may include one or more subchannels that are not contiguous in the channel diagram. In addition, larger channel groups may be used in some implementations. For example, the operating channels have bandwidths of 320 MHz, 640 MHz, or greater. The 320 MHz bandwidth may be divided into 16 20 MHz subchannels.

[0062] The primary channel is a common operating channel for all STAs that are members of the BSS. The secondary channel is a channel associated with the primary channel to create a channel wider than the primary channel.

[0063] In a 40 MHz BSS, the 20 MHz secondary channel is adjacent to the primary 20 MHz channel and together they form the 40 MHz channel of the 40 MHz BSS.

[0064] In an 80 MHz BSS, the secondary 20 MHz channel is adjacent to the primary 20 MHz channel and together they form the primary 40 MHz channel of the 80 MHz BSS. The secondary 40 MHz channel is adjacent to the primary 40 MHz channel and together they form the 80 MHz channel of the 80 MHz VHT BSS.

[0065] In a 160 MHz or 80+80 MHz BSS, the secondary 80 MHz channel excluding the primary 20 MHz channel together with the primary 80 MHz channel including the primary 20 MHz channel forms the 160 MHz or 80+80 MHz channel of the 160 MHz or 80+80 MHz BSS.

[0066] In a 320 MHz BSS, the secondary 160 MHz channel excluding the primary 20 MHz channel forms a 320 MHz channel of the 320 MHz BSS together with the primary 160 MHz channel including the primary 20 MHz channel.

[0067] Figure 6 An example of PPDU transmission is shown.

[0068] The WLAN device transmits PPDU by using four sub-channels CH1, CH2, CH3, and CH4 of the 80 MHz operating channel. The PPDU can have Figure 3 to Figure 4 Any PDDU format shown. The preamble and data in the PPDU may be repeated once per 20 MHz subchannel. Alternatively, only a portion of the preamble in the PPDU may be repeated once per 20 MHz subchannel.

[0069] The WLAN device will perform a Clear Channel Assessment (CCA) before sending a non-triggered transmission. CCA is a technique to avoid collisions. Other types may be called carrier sensing, carrier detection, listen before talk. CCA is performed by the WLAN device to determine whether the wireless communication medium (e.g., a subchannel group) is available or busy (due to another transmission). If the wireless communication medium is in use, the WLAN device may postpone transmission until CCA is performed again and the wireless communication medium is idle by another device.

[0070] There may be an existing system transmission that occupies a portion of the second subchannel CH2. Therefore, the wireless channel may be punctured to exclude the second subchannel CH2 from the transmission. Therefore, the PPDU is sent only on the first subchannel CH1, the third subchannel CH3, and the fourth subchannel CH4.

[0071] The punctured channel information may be indicated in a signal field (e.g., HE-SIG-A, U-SIG, or EHT-SIG). The punctured channel information may indicate which channels in the total bandwidth (e.g., 160 MHz or 320 MHz) are punctured and the puncturing pattern so that the receiving STA knows which channels are to process information and which channels are punctured and therefore unavailable or otherwise do not include information for the STA to process.

[0072] Figure 7 An example of UL MU transmission is shown.

[0073] UL MU operation allows the AP to request simultaneous immediate response frames from one or more STAs.

[0074] The AP may send a trigger frame to one or more STAs (e.g., STA1 and STA2). The trigger frame may be sent as a MU PPDU (e.g., HE MU PPDU or EHT MU PPDU). STA1 and STA2 may send a response PDU (e.g., HE TB PPDU or EHT TB PPDU) in response to the trigger frame. The interframe space between the PPDU containing the trigger frame and the TB PPDU is a short interframe space (SIFS). The AP sends an Ack or BlockAck frame to the responding STAs (e.g., STA1 and STA2) to confirm one or more TB PPDUs.

[0075] The trigger frame allocates resources for one or more PPDU transmissions and requests one or more PPDU transmissions. The trigger frame also carries other information required by the responding STA to send a TB PPDU or a non-HT PPDU. The trigger frame can be sent as various types, such as a basic trigger frame, a multi-user request to transmit (MU-RTS) frame, a MU-BAR, a beamforming report poll (BFRP) trigger frame, etc.

[0076] The trigger frame may include a UL bandwidth field, a channel sensing (CS) requirement field, one or more STA IDs, and one or more RU allocation fields. The UL bandwidth field indicates the bandwidth of the response PPDU. The CS requirement field indicates whether the responding STA needs to use energy detection (ED) to sense the medium and consider the medium state and network allocation vector (NAV) when determining whether to respond. One or more STA IDs identify one or more responding STAs. The RU allocation subfield indicates the RU allocation of the response PPDU.

[0077] The WLAN device classifies the received PPDU as inter-PPDU if (i) the received PPDU is transmitted by an AP that is not associated with the WLAN device, (ii) the BSS of the received PPDU is not the BSS of the WLAN device, or (iii) the received PPDU is a downlink MU PPDU and the WLAN device is an AP.

[0078] The WLAN device classifies the received PPDU as within the PPDU if (i) the received PPDU is transmitted by an AP associated with the WLAN device, (ii) the BSS of the received PPDU is the BSS of the WLAN device, or (iii) the received PPDU is a downlink MU PPDU and the WLAN device is an AP.

[0079] An inter-BSS PPDU may be a PPDU received by a receiving STA and transmitted to an AP (and / or BSS) not associated with the receiving STA. An intra-BSS PPDU may be a PPDU received by a receiving STA and transmitted to an AP (and / or BSS) associated with the receiving STA.

[0080] A STA may classify a received PPDU as an inter-BSS PPDU if at least one of the following conditions is true: ―The RXVECTOR parameter BSS_COLOR is not 0 and is not the BSS color of the BSS of which the STA is a member.

[0081] ―The PPDU is a VHT PPDU, and its RXVECTOR parameter PARTIAL_AID is not equal to the BSSID[39:47] of the BSS to which the STA is associated or any other BSS in the same multi-BSSID set or co-hosted BSSID set to which its BSS belongs, and the RXVECTOR parameter GROUP_ID is 0.

[0082] - The PPDU is a VHT PPDU whose RXVECTOR parameter PARTIAL_AID[5:8] is not equal to the 4 LSBs of the BSS color advertised by the BSS of which the STA is a member with dot11PartialBSSColorImplemented equal to true, and RXVECTOR parameter GROUP_ID is equal to 63 when the Partial BSS Color field in the most recent HE Operation element was 1.

[0083] ―The PPDU is a VHT MU PPDU or HE MU PPDU, its RXVECTOR parameter UPLINK_FLAG is equal to 0, and the STA is an AP.

[0084] ―A PPDU carries a frame with a BSSID field whose value is not the BSSID of the associated STA's BSS, or the BSSID of any other BSS in the same multi-BSSID set or co-hosted BSSID set to which its BSS belongs, or a wildcard BSSID.

[0085] ―The frame carried by the PPDU does not have a BSSID field, but has both a RA field and a TA field, the values ​​of which are not equal to the BSSID of the associated STA's BSS, or the BSSID of any other BSS in the same multi-BSSID set or co-hosted BSSID set to which its BSS belongs. The Individual / Group bit in the TA field value is forced to 0 before comparison.

[0086] A STA may classify a received PPDU as an intra-BSS PPDU if at least one of the following conditions is true: ― If the STA is a HE STA associated with a non-HE AP, the RXVECTOR parameter BSS_COLOR of the PPDU carrying the frame is the BSS color of the BSS of which the STA is a member, or the BSS color of any TDLS link to which the STA belongs.

[0087] The PPDU is a VHT PPDU with the RXVECTOR parameter PARTIAL_AID equal to the BSSID [39:47] of the BSS to which the STA is associated or any other BSS in the same multi-BSSID set or co-hosted BSSID set to which its BSS belongs, and the RXVECTOR parameter GROUP_ID equal to 0.

[0088] - The PPDU is a VHT PPDU with the RXVECTOR parameter PARTIAL_AID[5:8] equal to the 4 LSBs of the BSS color advertised by the BSS of which the STA is a member with dot11PartialBSSColorImplemented equal to true, the RXVECTOR parameter GROUP_ID equal to 63, and the Partial BSS Color field in the most recent HE Operation element is 1.

[0089] ―The frame carried by the PPDU has a RA, TA, or BSSID field value that is equal to the BSS ID of the BSS or any BSS to which the STA is associated or the BSSID of any other BSS in the same multi-BSSID set or co-hosted BSSID set to which the BSS belongs. The Individual / Group bit in the TA field value is forced to a value of 0 before comparison.

[0090] —The PPDU carries a control frame that does not have a TA field and has a RA field value that matches the saved TXOP holder address of any BSS to which the BSS or STA is associated or any other BSS in the same multi-BSSID set or co-hosted BSSID set to which the BSS belongs.

[0091] NAV is an indicator maintained by each STA of the time period during which the STA did not initiate transmission on the wireless medium (WM), regardless of whether the STA's Clear Channel Assessment (CCA) function senses that the WM is busy. When the NAV counter is not zero (or NAV indicates busy), the STA cannot access the channel. When the STA receives a PPDU that is not transmitted by the STA or is not sent to the STA, the STA can update the NAV (or set / reset the NAV counter).

[0092] The "backoff procedure" is a channel send (CS) procedure used to confirm whether the wireless medium (or channel) is idle. A STA that wishes to initiate the transmission of data frames and / or management frames needs to invoke the CS mechanism to determine the busy / idle status of the medium. If the medium is busy, the STA delays until the medium is determined to be idle without interruption for a period of time equal to the first interval (e.g., the extended interframe space (EIFS)) when the last transition to the idle medium was due to a frame detected on the medium that was not correctly received, otherwise equal to the second interval (e.g., the DCF interframe space (DIFS)). After this DIFS or EIFS medium idle time, the STA should generate a random backoff count before transmitting for additional delay time, unless the backoff counter already contains a non-zero value, in which case the selection of a random number is not required and is not performed. This process minimizes conflicts during contention between multiple STAs that have delayed to the same event.

[0093] The non-primary channel access mechanism is described below.

[0094] When the WLAN device receives an inter-BSS PPDU on a primary channel (eg, a primary 20 / 40 / 80 / 160 / 320 / 640 MHz channel), the WLAN device sets the NAV counter of the primary channel and records the occupied primary channel set.

[0095] In the traditional IEEE 802.11 protocol, when the primary channel is not idle, the WLAN device cannot access the entire working channel regardless of whether any secondary channel is idle. TXOP is obtained only based on the activity of the primary channel. Therefore, when the primary channel is busy, the STA cannot access the channel and cannot initiate any transmission.

[0096] Figure 8 A non-primary channel access mechanism according to an embodiment of the present invention is shown.

[0097] The AP may announce the primary channel and / or the alternate primary channel to the STA. The STA may receive a frame (e.g., a beacon frame) including information about at least one of the primary channel and the alternate primary channel. The frame may further include information about at least one secondary channel associated with the alternate primary channel. The primary channel may not overlap with the alternate primary channel in the frequency domain. The primary channel is used for baseline channel access (e.g., EDCA) for all types of STAs (e.g., 802.11a / b / g / n / ac / ax / be). The alternate primary channel is used for a non-primary channel access mechanism according to the embodiments described in this specification.

[0098] The alternate primary channel may be referred to by various terms, such as an additional primary channel, a selected primary channel, etc. When the primary channel is referred to as a first primary channel, the alternate primary channel is referred to as a second primary channel.

[0099] The alternative primary channel can be located in a non-primary channel. The alternative primary channel can be located in a secondary channel associated with the primary channel. The bandwidth of the alternative primary channel can be one of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz. The primary channel and the alternative primary channel should be located in different frequency bands (e.g., different 80 MHz frequency bands) or in different frequency bands.

[0100] When the NAV counter of the primary channel is set from the inter-BSS PPDU, the STA may invoke a new backoff procedure on the alternative primary channel, unless the alternative primary channel is a subset of the set of occupied primary channels. If the NAV counter of the primary channel expires, the backoff procedure of the alternative primary channel is stopped (i.e., the backoff counter of the alternative primary channel is reset). If the backoff counter of the alternative primary channel expires but the NAV counter of the primary channel has not expired, the STA may initiate a TXOP on the alternative primary channel. In this case, the duration of the TXOP cannot exceed the current NAV counter of the primary channel. The TXOP may use other idle non-primary channels.

[0101] Based on receiving the inter-BSS PPDU, the STA may switch from the primary channel to the alternate primary channel. Based on receiving the inter-BSS PPDU, the STA may monitor the alternate primary channel. "Monitoring the channel" means that the STA performs a CS on the channel to check whether the channel is idle to start PPDU transmission and / or means that the STA listens to the channel to receive a PPDU on the channel. The STA may check the idleness of the alternate primary channel regardless of whether any PPDU is received on the primary channel.

[0102] After the STA moves to the alternative primary channel, the STA may switch back to the primary channel before the NAV counter of the primary channel expires. When the NAV counter of the primary channel expires, the STA may switch back to the primary channel.

[0103] According to the non-primary channel access mechanism, when the primary channel is unavailable, the STA can temporarily switch to the alternative primary channel for PPDU transmission or PPDU reception.

[0104] Fig. 9 An example of a SERVICE field used to support a non-primary channel access mechanism is shown.

[0105] The data field in the PPDU carrying the (MU-)RTS frame may include a SERVICE field, a PSDU, and padding bits.

[0106] When the STA initiates a TXOP on the alternative primary channel, the STA may first exchange (MU-)RTS / CTS frames with the AP. The (MU-)RTS frame includes information that the STA obtains the TXOP from accessing the alternative primary channel. For example, the (MU-)RTS frame includes punctured channel information in the SERVICE field, where the punctured channel information indicates that the primary channel is punctured but the alternative primary channel is not punctured.

[0107] When the NAV counter of the primary channel is set from the inter-BSS PPDU, the STA may receive a (MU-)RTS frame on the alternative primary channel from a peer STA that supports the non-primary channel access mechanism. If the received (MU-)RTS frame indicates that the peer STA has obtained a TXOP by accessing the alternative primary channel (for example, the punctured channel information in the SERVICE field indicates that the primary channel is punctured but the alternative primary channel is not punctured) and the CS of the alternative primary channel is idle, the STA may send a CTS frame on the alternative primary channel. Otherwise, the STA does not send a CTS frame. When the NAV counter of the primary channel is not set from the inter-BSS PPDU (including the CS of the primary channel being idle), the STA may not transmit a CTS frame even if it receives a (MU-)RTS frame on the alternative primary channel from a peer STA that supports the non-primary channel access mechanism.

[0108] After the mobile STA moves to the alternative main channel, the mobile STA may transmit an RTS frame to the receiving STA on the alternative main channel. The RTS frame includes information about the alternative main channel information and / or an instruction indicating that the mobile STA moves to the alternative main channel. When the receiving STA also moves to the alternative main channel, the receiving STA may send a CTS frame. When the receiving STA does not move to the alternative main channel, the receiving STA may not send a CTS frame. If the receiving STA does not support the alternative main channel, the receiving STA may not send a CTS frame.

[0109] After the STA moves to the alternative primary channel, the STA may not send a CTS frame in response to an RTS frame received on the primary channel.

[0110] When a STA that receives an RTS frame on an alternative primary channel sends a CTS frame, the CTS frame may indicate a channel that cannot be used due to adjacent channel interference (ACI) or alternative adjacent channel interference (AACI) (caused by PPDUs transmitted by other STAs on the primary channel). For example, the CTS frame includes punctured channel information in a SERVICE field, wherein the punctured channel information indicates a channel that cannot be used due to performance degradation caused by ACI or AACI.

[0111] Since the CTS frame transmitted in response to the MU-RTS frame has the same content, in order to report punctured channel information specific to each STA, the AP may transmit a Punctured Channel Report Poll (PCRP)-trigger frame.

[0112] After receiving the PCRP-trigger frame, the STA reports the punctured channel information in the Punctured Channel Report (PCR) control subfield in the A-Control field in the QoS Null / Data / Management frame sent in the TB PPDU. The PCR control subfield may have 6 bits of information. The punctured channel information may be encoded as RU units instead of 20 MHz channel units.

[0113] The AP may transmit an Interference Channel Report Poll (ICRP)-trigger frame instead of puncturing the channels affected by ACI or AACI. After receiving the ICRP-trigger frame, the STA reports the interference channel information in the Interference Channel Report (ICR) control subfield in the A-Control field in the QoS Null / Data / Management frame sent in the TB PPDU. The interference channel information is represented by the channel number affected by ACI or AACI, the interference strength on the corresponding channel, and the recommended MCS on the corresponding channel. The interference channel information may be encoded as RU units instead of 20 MHz channel units.

[0114] Fig.10 FIG. 4 shows a non-primary channel access mechanism according to an embodiment of the present invention. Figure 8 Compared to the illustrated embodiment, monitoring of the primary channel and the alternative primary channel can be performed simultaneously.

[0115] When the NAV counter of the primary channel is set from the inter-BSS PPDU, the STA may invoke the backoff procedure after sensing the wireless medium on the alternative primary channel during the non-primary CS (NPCS) timer, unless the alternative primary channel is a subset of the occupied primary channel set. If the NAV counter of the primary channel expires, the backoff procedure of the alternative primary channel is stopped (i.e., the backoff counter of the alternative primary channel is reset).

[0116] When the NAV counter of the primary channel is set from the inter-BSS PPDU, the STA senses the wireless medium on the alternative primary channel during the non-primary CS (NPCS) timer. If the CS state of the wireless medium is identified as idle or busy during the NPCS timer, the STA invokes a new backoff procedure.

[0117] When the NAV counter of the primary channel is set from the inter-BSS PPDU, the STA can invoke the new backoff procedure if the wireless medium is idle during the NPCS timer. When the NAV of the primary channel is set, the STA can invoke the backoff procedure on the alternate primary channel if the alternate primary channel is idle while the NPCS timer is running.

[0118] The NPCS timer may indicate the interval for monitoring the alternative primary channel. The NPCS timer may indicate the interval for monitoring the alternative primary channel before invoking the backoff procedure on the alternative primary channel. The NPCS timer may indicate the interval for monitoring the alternative primary channel before switching to the alternative primary channel.

[0119] The NPCS timer may be referred to as an NPCS interval. The AP may send information about the value of the NPCS timer or the NPCS interval. The NPCS interval may be greater than any interframe space (IFS). The NPCS interval may be a given integer multiple of the IFS. When monitoring during the NPCS interval, no random backoff counter is generated. When monitoring the alternate primary channel during the NPCS interval, the alternate primary channel may be detected as idle when the alternate primary channel remains idle during the NPCS interval.

[0120] STA can monitor both the primary channel and the alternative primary channel at the same time. STA can immediately invoke the backoff procedure on the primary channel. After STA confirms that the alternative primary channel is idle during the NPCS timer, STA can invoke the backoff procedure on the alternative primary channel.

[0121] Fig.11 A non-primary channel access mechanism according to another embodiment of the present invention is shown.

[0122] When the NAV counter of the primary channel is set from the inter-BSS PPDU, if the alternative primary channel is occupied by the inter-BSS PPDU, the occupied time is considered as part of the NPCS timer even if the wireless medium is not idle. Therefore, the STA can invoke a new backoff procedure after the NPCS timer.

[0123] Fig.12 A non-primary channel access mechanism according to yet another embodiment of the present invention is shown.

[0124] When setting the NAV counter of the primary channel from the inter-BSS PPDU, if the alternative primary channel is occupied by the intra-BSS PPDU, the occupied time is considered as part of the NPCS timer even if the wireless medium is not idle. Therefore, the STA can invoke a new backoff procedure after the NPCS timer.

[0125] When the alternative primary channel is occupied by a PPDU (e.g., an inter-BSS PPDU and / or an intra-BSS PPDU), the STA considers the alternative primary channel to be idle for a portion of the NPCS timer that overlaps with the duration of the occupied PPDU. When the alternative primary channel is occupied by a specific STA (a STA not associated with the STA's AP and / or a STA associated with the STA's AP), the STA considers the alternative primary channel to be idle for a portion of the NPCS timer that overlaps with the occupation duration of the specific STA.

[0126] When the alternative primary channel is occupied by a PPDU (e.g., an inter-BSS PPDU and / or an intra-BSS PPDU), the STA may ignore the CCA result of the alternative primary channel for the duration of the PPDU. When the alternative primary channel is occupied by a PPDU (e.g., an inter-BSS PPDU and / or an intra-BSS PPDU), the STA may not monitor the alternative primary channel for the duration of the PPDU. The NPCS interval may be reduced by the amount of interval that overlaps with the duration of the occupied PPDU.

[0127] When the NAV counter of the primary channel is set from the inter-BSS PPDU, if the backoff counter of the alternative primary channel expires but the NAV counter of the primary channel has not expired, the STA can initiate a TXOP on the alternative primary channel. In this case, the duration of the TXOP does not exceed the current NAV counter of the primary channel. The TXOP can use other idle non-primary channels.

[0128] When a STA initiates a TXOP on an alternative primary channel, the STA first exchanges (MU-)RTS / CTS frames. The (MU-)RTS frame includes the bandwidth information on which the STA obtains the TXOP from accessing the alternative primary channel. The STA addressed by the RTS frame in a non-HT or non-HT repeated PPDU with bandwidth signaling TA and RXVECTOR parameter DYN_BANDWIDTH_IN_NON_HT equal to Static behaves as follows: (i) If NAV indicates idle and the CCA of all auxiliary channels (auxiliary 20 MHz channel, auxiliary 40 MHz channel and auxiliary 80 MHz channel) in the channel width indicated by the RXVECTOR parameter CH_BANDWIDTH_IN_NON_HT of the RTS frame are idle within PIFS before the start of the RTS frame, the STA shall respond with a CTS frame carried in a non-HT or non-HT repeat PPDU after SIFS. The TXVECTOR parameters CH_BANDWIDTH and CH_BANDWIDTH_IN_NON_HT of the CTS frame shall be set to the same value as the RXVECTOR parameter CH_BANDWIDTH_IN_NON_HT of the RTS frame.

[0129] (ii) Otherwise, the STA SHOULD NOT respond with a CTS frame.

[0130] The behavior of a STA addressed by a TA with bandwidth signaling and RXVECTOR parameter DYN_BANDWIDTH_IN_NON_HT equal to dynamic non-HT or RTS frame in non-HT repeated PPDU is as follows: (i) If the NAV indicates idle, the STA shall respond with a CTS frame in a non-HT or non-HT repeated PPDU after SIFS. The TXVECTOR parameters CH_BANDWIDTH and CH_BANDWIDTH_IN_NON_HT of the CT frame shall be set to any channel width for which the CCA on all secondary channels has been idle for PIFS before the start of the RTS frame and which is less than or equal to the channel width indicated in the RXVECTOR parameter CH_BANDWIDTH_IN_NON_HT of the RTS frame.

[0131] (ii) Otherwise, the STA SHOULD NOT respond with a CTS frame.

[0132] Fig.13 A non-primary channel access mechanism according to yet another embodiment of the present invention is shown.

[0133] When a STA listening on an alternative primary channel receives a (MU-)RTS frame on an alternative primary channel from a peer STA supporting a non-primary channel access mechanism, the STA should not respond with a CTS frame if the bandwidth information indicated in the received (MU-)RTS frame includes the primary channel. This happens because the peer STA obtains a TXOP by accessing the primary channel. Alternatively, an alternative is that the STA responds with a CTS frame on an alternative primary channel that does not include the primary channel. The peer STA then initiates a frame exchange on the alternative primary channel.

[0134] The AP receives the Inter-BSS PPDU and sets the NAV. The AP switches to the Alternate Primary Channel located on the Secondary 80 MHz segment. After recognizing that the wireless medium is idle for the duration of the NPCS timer, the AP invokes a new backoff procedure on the Alternate Primary Channel.

[0135] While executing the backoff procedure, the AP receives an RTS frame with bandwidth signaling information equal to 160 MHz. Since the 160 MHz channel covers the primary channel, the AP does not send a CTS response. It is possible that the peer STA sends a 160 MHz RTS after getting a TXOP on the primary channel. The hidden node problem causes this out-of-sync state between the AP and STA.

[0136] When a STA listening on an alternative primary channel receives a (MU-)RTS frame on an alternative primary channel from a peer STA supporting a non-primary channel access mechanism, if the duration information indicated in the received (MU-)RTS frame exceeds the NAV counter of the STA's primary channel, the STA may respond without a CTS frame or with a CTS frame with reduced duration information. The reduced duration information is a value less than or equal to the NAV counter of the STA's primary channel. This occurs because the two STAs receive different inter-BSS PPDUs on the primary channel.

[0137] When a STA supporting a non-primary channel access mechanism has an additional association / connection with an Overlapping Basic Service Set (OBSS), the STA should provide the relevant OBSS information (eg, BSSID and BSS color).

[0138] In this case, if the inter-BSS PPDU that triggered the non-primary channel mechanism is sent from the OBSS provided by the STA, the peer STA that obtained the TXOP using the non-primary channel access mechanism should not initiate frame exchange to the STA.

[0139] Fig.14 A non-primary channel access mechanism according to yet another embodiment of the present invention is shown.

[0140] After the STA switches to the alternative primary channel, the STA may monitor the alternative primary channel for PPDU reception. Before / after the STA switches to the alternative primary channel, the STA may send an indication to the AP that the STA switches to the alternative primary channel.

[0141] When the STA receives an RTS frame from the AP on the alternative primary channel, the STA may send a CTS frame on the alternative primary channel as a response to the RTS frame. When the STA receives a trigger frame from the AP on the alternative primary channel, the STA may receive a DL PPDU according to the allocation in the trigger frame.

[0142] Fig.15 A non-primary channel access mechanism applied to a peer-to-peer application according to an embodiment of the present invention is shown.

[0143] The non-primary channel access mechanism can be extended to peer-to-peer (P2P) applications. When a P2P STA receives an intra-BSS PPDU on a primary channel (e.g., primary 20 / 40 / 80 / 160 / 320 / 640 MHz channel) destined for its associated AP, the P2P STA sets the NAV counter of the primary channel and records the primary channel set that has been occupied.

[0144] When the NAV counter of the primary channel is set from an intra-BSS PPDU sent to its associated AP, the STA may invoke a new backoff procedure after sensing the wireless medium on the alternative primary channel during the NPCS timer, unless the alternative primary channel is a subset of the set of occupied primary channels. If the NAV counter of the primary channel expires, the backoff procedure of the alternative primary channel stops (i.e., the backoff counter of the alternative primary channel is reset).

[0145] If the backoff counter of the alternative primary channel expires but the NAV counter of the primary channel has not expired, the STA can initiate a TXOP to the peer P2P STA on the alternative primary channel. In this case, the duration of the TXOP does not exceed the current NAV counter of the primary channel. The TXOP can use other idle non-primary channels.

[0146] As used herein, phrases referring to "at least one of" or "one or more of" a list of items refer to any combination of those items, including single members. For example, "at least one of a, b, and c" is intended to cover the following possibilities: only a, only b, only c, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a, b, and c.

[0147] The various illustrative components, logic, logic blocks, modules, circuits, operations, and algorithmic processes described in connection with the embodiments disclosed herein may be implemented as electronic hardware, firmware, software, or a combination of hardware, firmware, or software, including the structures disclosed in this specification and their structural equivalents. The interchangeability of hardware, firmware, and software has been generally described in terms of functionality and illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware, firmware, or software depends on the specific application and the design constraints imposed on the overall system.

[0148] Although the operation is depicted in a specific order in the figure, this should not be understood as requiring to perform such operation in the specific order shown or in a continuous order, or requiring to perform all the operations shown, to achieve the desired result. In addition, the figure can schematically depict one or more example processes in the form of a flow chart or a flow diagram. However, other operations that are not depicted can be incorporated into the schematically shown example process. For example, one or more additional operations can be performed before, after, simultaneously or between any of the operations shown. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of various system components in the above-mentioned implementation should not be understood as requiring all to carry out this separation in all implementations, and it should be understood that the program components and the system can usually be integrated together in a single software product or packaged into multiple software products.

Claims

1. A method for accessing a channel in a wireless local area network, the method being performed by a station and comprising: receiving a frame including information about a first primary channel and a second primary channel; Simultaneously monitoring the first primary channel and the second primary channel; as well as When a network allocation vector (NAV) of the first primary channel is set but the second primary channel is idle, switching from the first primary channel to the second primary channel to initiate a physical layer protocol data unit (PPDU) transmission on the second primary channel.

2. The method according to claim 1, further comprising: Before the NAV of the first primary channel expires, switching back to the first primary channel.

3. The method according to claim 1, wherein: The NAV of the first primary channel is set upon receiving a PPDU transmitted by an access point not associated with the station.

4. The method according to claim 1, wherein: When the second primary channel is occupied by a PPDU transmitted by an access point associated with the station, monitoring of the second primary channel is stopped.

5. The method according to claim 1, wherein: Simultaneously monitoring the first primary channel and the second primary channel comprises: performing a first backoff procedure on the first primary channel; and Channel sensing (CS) is performed during the non-primary CS interval and a second backoff procedure is performed on the second primary channel.

6. The method according to claim 1, wherein: The second main channel does not overlap with the first main channel in the frequency domain.

7. The method according to claim 6, wherein: The second primary channel is located in at least one secondary channel of the first primary channel.

8. The method according to claim 1, wherein: The frame is received on the first primary channel.

9. A device for accessing a channel in a wireless local area network, the device comprising: processor; as well as a memory operably coupled to the processor and configured to store instructions that, when executed by the processor, cause the device to perform functions, the functions comprising: receiving a frame including information about a first primary channel and a second primary channel; Simultaneously monitoring the first primary channel and the second primary channel; and When a network allocation vector (NAV) of the first primary channel is set but the second primary channel is idle, switching from the first primary channel to the second primary channel to initiate a physical layer protocol data unit (PPDU) transmission on the second primary channel.

10. The device according to claim 9, wherein: The functionality also includes: Before the NAV of the first primary channel expires, switching back to the first primary channel.

11. The device according to claim 9, wherein: The NAV of the first primary channel is set upon receiving a PPDU transmitted by an access point not associated with the station.

12. The device according to claim 9, wherein: When the second primary channel is occupied by a PPDU transmitted by an access point associated with the station, monitoring of the second primary channel is stopped.

Images