Communication method and apparatus using sub-channel in wireless local area network

Abstract

An object of the present invention is to perform communication by using a sub-channel in a wireless local area network system, and a method for operating an access point (AP) comprises the steps of: detecting that another device other than a station (STA) connected to the AP performs communication on a main channel; acquiring information related to a duration of performing the communication; switching the working channel from the main channel to the at least one sub-channel during the duration; transmitting or receiving data on the sub-channels; and switching the working channel to the main channel.

Description

Technical Field

[0001] This invention relates to a wireless local area network (WLAN) system, and more specifically, to a communication method and apparatus utilizing sub-channels in a wireless local area network system. Background Technology

[0002] Recently, with the widespread adoption of mobile devices, wireless LAN technology, which provides fast wireless communication services to mobile devices, has attracted attention. Wireless LAN technology is a technology that uses wireless communication to enable mobile devices (such as smartphones, tablets, laptops, portable multimedia players, embedded devices, etc.) to wirelessly access the internet.

[0003] With the emergence of applications requiring higher throughput and real-time transmission, extended frequency bandwidth and / or efficient retransmission operations can be supported in wireless LANs. Furthermore, simultaneous use of multiple channels or multiple links can be supported.

[0004] On the other hand, the techniques described in the background section are written to improve the understanding of the background of the present invention, and may include content that is not yet known to those skilled in the art to which the present invention pertains. Summary of the Invention

[0005] Technical issues The present invention provides a method and apparatus for performing communication using a primary channel and a sub-channel in a wireless local area network (WLAN) system.

[0006] This invention provides a method and apparatus for performing channel detection on the main channel and performing communication based on the channel detection results in a WLAN system.

[0007] The present invention provides a method and apparatus for performing communication using a sub-channel when the main channel is used by another device in a WLAN system.

[0008] The present invention provides a method and apparatus for performing communication using a sub-channel when the use of a primary channel varies among wireless local area network devices in a wireless local area network system.

[0009] The present invention provides a method and apparatus for performing communication when certain sub-channels in a wireless local area network system are unavailable.

[0010] The technical objectives to be achieved in this invention are not limited to those described above, and those skilled in the art who apply the technical configuration of this invention may consider other technical objectives not mentioned herein from the embodiments of the invention described below.

[0011] Technical solution According to an embodiment of the present invention, a method for operating an access point (AP) in a wireless local area network system includes: detecting that a device other than at least one station (STA) associated with the AP is performing communication on a main channel, obtaining information related to the duration of the communication, switching the operating channel from the main channel to at least one sub-channel during the duration, transmitting or receiving data on the sub-channel, and switching the operating channel back to the main channel.

[0012] According to an embodiment of the present invention, a method for an operator station (STA) in a wireless local area network system includes: detecting that a device other than an access point (AP) associated with the STA is performing communication on a main channel, obtaining information related to the duration of the communication, switching the operating channel from the main channel to at least one sub-channel during the duration, transmitting or receiving data on the sub-channel, and switching the operating channel back to the main channel.

[0013] According to an embodiment of the present invention, an access point (AP) in a wireless local area network system includes a transceiver and a processor connected to the transceiver. The processor is configured to detect that a device other than at least one station (STA) associated with the AP is performing communication on a primary channel, obtain information related to the duration of the communication, switch the operating channel from the primary channel to at least one sub-channel during the duration, transmit or receive data on the sub-channel, and switch the operating channel back to the primary channel.

[0014] According to an embodiment of the invention, a station (STA) in a wireless local area network system includes a transceiver and a processor connected to the transceiver. The processor is configured to detect that a device other than an access point (AP) associated with the STA is performing communication on the main channel, obtain information related to the duration of the communication, switch the operating channel from the main channel to at least one sub-channel during the duration, transmit or receive data on the sub-channel, and switch the operating channel back to the main channel.

[0015] Beneficial effects According to the present invention, when the main channel of a wireless local area network system is busy, communication can be performed on a sub-channel.

[0016] According to the present invention, in a wireless local area network system, communication can be performed on a sub-channel based on the amount of energy detected on the main channel.

[0017] According to the present invention, communication utilizing sub-channels can be performed efficiently in a wireless local area network system.

[0018] The effects obtained in this invention are not limited to those described above, and those skilled in the art of applying the technical configurations of this invention can clearly deduce and understand other effects not mentioned above from the following description of the embodiments of this invention. That is, those skilled in the art can also deduce unintended effects in implementing the configurations described in this invention from the embodiments of this invention. Attached Figure Description

[0019] Figure 1 This is a block diagram illustrating a first embodiment of a communication node constituting a wireless local area network system.

[0020] Figure 2 A first embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0021] Figure 3 A second embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0022] Figure 4 A third embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0023] Figure 5 A fourth embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0024] Figure 6 A fifth embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0025] Figure 7 A sixth embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0026] Figure 8 A flowchart illustrating the process by which a station (STA) performs communication using a sub-channel according to one embodiment of the present invention is shown.

[0027] Figure 9 A flowchart illustrating the process by which an access point (AP) performs communication using a sub-channel according to one embodiment of the present invention is shown. Detailed Implementation

[0028] This invention can have various modifications and embodiments, and specific embodiments are shown in the accompanying drawings and described in detail in the specification. However, this is not intended to limit the invention to the specific embodiments, but should be understood to include all modifications, equivalents, or alternatives contained within the spirit and technical scope of the invention.

[0029] The terms "first," "second," etc., can be used to describe various components, but components should not be limited by the terms. Terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the invention, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component. Terms and / or include combinations of multiple related descriptive terms or any one of multiple related descriptive terms.

[0030] When it is said that a component is "joined to" or "connected to" another component, it should be understood that one component is connected to the other component directly or through any other component in between. On the other hand, when it is said that a component is "directly connected to" or "directly joined to" another component, it should be understood that there are no other components between the components.

[0031] The terminology used in this invention is for describing particular embodiments only and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this invention, terms such as “comprising” or “having” are intended to specify the presence of features, quantities, steps, operations, components, parts or combinations thereof described in the specification, but should be understood not to preclude the possibility of the presence or addition of one or more other features, quantities, steps, operations, components, parts or combinations thereof.

[0032] Unless otherwise defined, all terms used herein (including technical or scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in general dictionaries shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art and shall not be interpreted as having an ideal or overly formal meaning unless expressly defined herein.

[0033] In the following description, various exemplary embodiments of the invention will be described in more detail with reference to the accompanying drawings. In describing the invention, for ease of overall understanding, the same reference numerals are used for the same components in the drawings, and repeated descriptions of the same components are omitted.

[0034] The following describes a wireless communication system applying embodiments of the present invention. The wireless communication system applying embodiments of the present invention is not limited to the following description, and the embodiments of the present invention can be applied to various wireless communication systems. The wireless communication system may be referred to as a "wireless communication network".

[0035] Figure 1 This is a block diagram illustrating a first embodiment of a communication node constituting a wireless local area network system.

[0036] refer to Figure 1Communication node 100 can be an access point (AP), a station (STA), an AP multi-link device (MLD), or a non-AP MLD. An access point can refer to an AP, and a station can refer to a STA or a non-AP STA. The operating channel width supported by the AP can be 20 MHz, 80 MHz, or 160 MHz, etc. The operating channel width supported by the STA can be 20 MHz or 80 MHz.

[0037] Communication node 100 may include at least one processor 110, memory 120, and at least one transmitting / receiving device 130 connected to a network and performing communication. Transmitting / receiving device 130 may also be referred to as a transceiver, radio frequency (RF) unit, or RF module. Additionally, communication node 100 may further include an input interface device 140, an output interface device 150, and a storage device 160. Components included in communication node 100 can be connected via bus 170 and perform communication between them.

[0038] However, each component included in communication node 100 may be connected not via common bus 170, but via a separate interface or separate bus around processor 110. For example, processor 110 may be connected via a dedicated interface to at least one of memory 120, transmitting / receiving device 130, input interface device 140, output interface device 150, and storage device 160.

[0039] Processor 110 can execute program instructions stored in at least one of memory 120 and storage device 160. Processor 110 can be a central processing unit (CPU), graphics processing unit (GPU), or dedicated processor that performs methods according to embodiments of the present invention. Memory 120 and storage device 160 can each be configured as at least one volatile storage medium and at least one non-volatile storage medium. For example, memory 120 can be configured as at least one read-only memory (ROM) and random access memory (RAM).

[0040] In the following description, an embodiment of a method for a wireless local area network (WLAN) device to perform communication using a sub-channel will be illustrated with reference to the accompanying drawings. The WLAN device includes an access point (AP) and a station (STA). The WLAN device may be referred to as a WLAN terminal. Alternatively, a WLAN terminal may refer to any WLAN device other than an AP. When communication is not possible on the main channel, the WLAN device may utilize a sub-channel to perform communication. For example, if other devices are communicating on the main channel, interference may occur in the communication of the WLAN device. According to one embodiment of the invention, communication can be performed using a sub-channel even when other devices are communicating on the main channel. The bandwidth of the main channel and the sub-channel may be the same. Alternatively, the bandwidth of the main channel and the sub-channel may be different from each other. To perform communication, the AP and STA may detect communication by other devices on the main channel. In the following description, the sub-channel may be referred to as an auxiliary main channel or an auxiliary channel.

[0041] Figure 2 A first embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0042] refer to Figure 2 Wireless LAN terminals can operate on wireless LAN channels (e.g., 20MHz, 40MHz, 80MHz, 160MHz (or 80+80MHz), 320MHz channels). Wireless LAN terminals may include AP 1 and STA 1 associated with AP 1. Multiple wireless LAN terminals may be further associated with AP 1. Communication can be performed between AP 1 and the wireless LAN terminals associated with AP 1 using wireless LAN channels. Communication between wireless LAN terminals other than AP 1 and wireless LAN terminals associated with AP 1 can be referred to as Overlapping Basic Service Set (OBSS) communication. OBSS communication may cause interference to AP 1 and the wireless LAN terminals associated with AP 1.

[0043] In a wireless LAN channel, a main channel 200 and a sub-channel 210 can be configured. The main channel 200 and sub-channel 210 can be configured or negotiated between AP 1 and the wireless LAN terminals associated with AP 1. The main channel 200 can be a channel that includes a primary 20MHz channel. The sub-channel 210 can be a channel that does not include the primary 20MHz channel. At least one sub-channel 210 can exist. For example, the wireless LAN channel can be 40MHz, the primary 20MHz channel can be the main channel 200, and the non-primary 20MHz channel can be the sub-channel 210. As another example, the wireless LAN channel can be 80MHz, the main channel 200 can be a 40MHz channel that includes the primary 20MHz channel, and the remaining 40MHz channel can be the sub-channel 210. Alternatively, the primary 20MHz channel can be the main channel 200, and the remaining 20MHz channels can be three sub-channels 210. That is, the configuration of the main channel 200 and sub-channel 210 can be configured in various ways. Sub-channel 210 can also be referred to as "auxiliary main channel", "auxiliary channel" or "alternative channel". For example, in an 80MHz channel consisting of one main channel 200 and three sub-channels 210 as in the example above, the three sub-channels 210 can be referred to as three auxiliary main channels.

[0044] Figure 2 This is an implementation scheme for the presence of a main channel 200 and a sub-channel 210. However, this implementation scheme is not intended to limit operation to the presence of only a main channel 200 and a sub-channel 210, and it should be understood that wireless LAN terminals can operate in the same or similar manner as in this implementation scheme, even under various configurations of the main channel 200 and the sub-channel 210.

[0045] AP 1 and STA 1 can perform channel detection and / or channel access operations (e.g., EDCA backoff operation or backoff operation) on the main channel 200. AP 1 can detect and decode frames transmitted on the OBSS on the main channel 200 and identify the communication duration of the OBSS. For example, the frames transmitted on the OBSS include at least one RTS frame 220 or a data frame. The communication duration of the OBSS can be identified by information in the duration field present in the MAC header of the RTS frame 220 and / or information included in the PHY preamble of the RTS frame 220 (e.g., L-SIG information, etc.). When detecting the communication duration by receiving and decoding frames transmitted on the OBSS, a basic network allocation vector (NAV) that is not transmitted during the corresponding interval is set. Alternatively, AP 1 and STA 1 must receive a CTS frame after receiving an RTS frame from the OBSS to set the basic NAV based on the communication of the OBSS. Alternatively, AP 1 and STA 1 must receive a physical layer preamble within the NAVTimeout period after receiving the OBSS CTS frame to acknowledge the basic NAV. If AP 1 and STA 1 do not receive an RTS frame after receiving the OBSS CTS frame or do not receive a physical layer preamble within the NAVTimeout period, the basic NAV set by the OBSS RTS frame can be canceled. Since AP 1 has already received the OBSS RTS frame, it can wait until it receives a subsequently transmitted OBSS CTS frame or PHY preamble. If AP 1 receives the OBSS CTS frame or PHY preamble, AP 1 can operate by moving to a subchannel. That is, AP 1 can operate the subchannel without immediately upon receiving the OBSS RTS frame, but can operate the subchannel after acknowledging the basic NAV. The basic NAV can be confirmed when a CTS frame of the OBSS is received, or when the BSS color, TXOP field, and length field present in the PHY preamble of the OBSS frame are decoded, or when at least one MPDU is successfully decoded after receiving a data frame from the OBSS. In this case, AP 1 and STA 1 can operate on the sub-channel. AP 1 can operate on sub-channel 210 during the communication duration of the OBSS. The communication duration of the OBSS is referred to as the "sub-channel communication possible interval" or "communication possible interval". However, due to differences in communication range or channel conditions, STA 1 may not receive frames transmitted on the OBSS. That is, STA 1 may not be able to decode frames transmitted on the OBSS. STA 1 can detect the energy of frames transmitted on the OBSS. That is, STA 1 can detect the presence of frame transmission on the OBSS. An energy threshold for switching to sub-channel 210 can be set in STA 1.The energy threshold can be a preset value, a value broadcast by AP 1 via a beacon, or a value negotiated between STA 1 and AP 1. If the energy of the RTS frame of the OBSS detected by STA 1 is equal to or greater than the energy threshold, STA 1 can operate on subchannel 210. On subchannel 210, AP 1 and STA 1 can perform channel access operations. For example, AP 1 can perform an EDCA backoff operation on subchannel 210. If AP 1's channel access operation is successful, AP 1 can send a downlink frame 230 to STA 1 on the subchannel, and STA 1 can send a response frame (e.g., a Block Ack (BA) frame) to AP 1. Alternatively, if STA 1's channel access operation is successful, STA 1 can send an uplink frame to AP 1. STA 1 may not know the communication duration of the OBSS from the frames transmitted by the OBSS. If STA 1 cannot know the communication duration of the OBSS, STA 1 can send an RTS frame to AP 1. A specific value (e.g., a duration field set to 0) can be indicated in the MAC header of an RTS frame. An RTS frame with a specific value set can indicate a "request for communication possible interval information." AP 1 can receive an RTS frame with a specific value set and send a CTS frame to STA 1. AP 1 can indicate communication possible interval information via the MAC header of the CTS frame (e.g., a duration field). STA 1 can send uplink frames to AP 1 within the communication possible interval. If AP 1 does not know the communication possible interval information, it can transmit a CTS frame by setting a specific value in the MAC header (e.g., a duration field set to 0). If STA 1 does not know the communication possible interval information, STA 1 does not transmit data frames and terminates communication on sub-channel 210. Upon receiving a CTS frame, STA 1 immediately switches its operation to the main channel 200. AP 1 and all other STAs that receive the RTS frame and / or CTS frame and realize they do not know the communication possible interval information also immediately switch their operation to the main channel 200.

[0046] Alternatively, STA 1 can decode frames transmitted on the OBSS, and AP 1 may not have yet decoded frames transmitted on the OBSS. AP 1 can operate on subchannel 210 if the energy of a frame transmitted on the OBSS detected by AP 1 is greater than or equal to an energy threshold. AP 1 may not know the communication duration information of the OBSS and may send RTS frames with a specific set value to STA 1. AP 1 can receive RTS frames with a specific set value and send CTS frames indicating a possible communication interval to AP 1. AP 1 can send downlink frames to STA 1 within the possible communication interval. On subchannel 210, communication between AP 1 and STA 1 can end within the communication duration of the OBSS.

[0047] If STA 1 is unaware of the possible communication interval information, it can transmit a CTS frame by setting a specific value in the MAC header (e.g., a duration field set to 0). If AP 1 is unaware of the possible communication interval information, it does not transmit a data frame and terminates communication on sub-channel 210. Upon receiving a CTS frame, AP 1 immediately switches operation to the main channel 200. All STAs that receive RTS frames and / or CTS frames and realize they are unaware of the possible communication interval information also immediately switch operation to the main channel 200.

[0048] On sub-channel 210, frame transmission and reception must be performed within the communication duration of the OBSS. The end time of frame transmission and reception on sub-channel 210 must take into account the switching delay of the main channel 200. Frame transmission and reception on sub-channel 210 must be completed before the channel switching delay, and the AP and all STAs must switch to the main channel. Before the end of the OBSS communication duration, AP 1 and all STAs associated with AP 1 can communicate on the main channel 200 starting from the end time of the OBSS communication duration by moving to the main channel 200. Information regarding possible communication intervals can be indicated by taking into account at least one of the OBSS communication duration or the switching delay to the main channel. The OBSS communication duration can be the transmission time length of an OBSS TXOP or a PPDU.

[0049] Figure 3 A second embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0050] refer to Figure 3Wireless LAN terminals can operate on wireless LAN channels (e.g., 20MHz, 40MHz, 80MHz, 160MHz (or 80+80MHz), 320MHz channels). Wireless LAN terminals may include AP 1 and STA 1 associated with AP 1. Multiple wireless LAN terminals may be further associated with AP 1. Communication can be performed between AP 1 and the wireless LAN terminals associated with AP 1 using wireless LAN channels. Communication between wireless LAN terminals other than AP 1 and wireless LAN terminals associated with AP 1 can be referred to as Overlapping Basic Service Set (OBSS) communication. OBSS communication may cause interference to AP 1 and the wireless LAN terminals associated with AP 1.

[0051] In a wireless LAN channel, a primary channel 300 and a sub-channel 310 can be configured. The primary channel 300 and sub-channel 310 can be configured or negotiated between AP 1 and the wireless LAN terminals associated with AP 1. The primary channel 300 can be a channel that includes a primary 20MHz channel. The sub-channel 310 can be a channel that does not include the primary 20MHz channel. At least one sub-channel 310 can exist. For example, the wireless LAN channel can be 40MHz, the primary 20MHz channel can be the primary channel 300, and the non-primary 20MHz channel can be the sub-channel 310. As another example, the wireless LAN channel can be 80MHz, the primary channel 300 can be a 40MHz channel that includes the primary 20MHz channel, and the remaining 40MHz channel can be the sub-channel 310. Alternatively, the primary 20MHz channel can be the primary channel 300, and the remaining 20MHz channels can be three sub-channels 310. That is, the configuration of the primary channel 300 and sub-channel 310 can be configured in various ways. Sub-channel 310 can also be referred to as an "auxiliary main channel," "auxiliary channel," or "alternative channel." For example, in an 80MHz channel consisting of one main channel 300 and three sub-channels 310 as described above, the three sub-channels 310 can be referred to as three auxiliary main channels. The sub-channel 310 can be simply called sub-channel 310.

[0052] Figure 3 This is an implementation scheme for the presence of one main channel 300 and one sub-channel 310. However, this implementation scheme is not intended to limit operation to the presence of only one main channel 300 and one sub-channel 310, and it should be understood that wireless LAN terminals can operate in the same or similar manner as in this implementation scheme, even with various configurations of the main channel 300 and the sub-channel 310.

[0053] AP 1 and STA 1 can perform channel detection and / or channel access operations (e.g., EDCA backoff operation or backoff operation) on the main channel 300. AP 1 can detect and decode the RTS frame 320 of the OBSS on the main channel 300 and know the communication duration of the OBSS. The communication duration of the OBSS can be known through information in the duration field present in the MAC header of the RTS frame 320 and / or information included in the PHY preamble of the RTS frame 320 (e.g., L-SIG information, etc.). AP 1 can operate on the sub-channel 310 during the communication duration of the OBSS. The communication duration of the OBSS is referred to as the "sub-channel 310 communication possible range" or "communication possible range". However, depending on the communication possible range or channel state, STA 1 may not detect and decode the RTS frame 320 of the OBSS. STA 1 can detect the energy of the CTS frame 330 of the OBSS or decode the CTS frame 330. If the energy of the CTS frame 330 of the OBSS detected by STA 1 is greater than the energy threshold set in STA 1, STA 1 can perform communication on sub-channel 310. Alternatively, if STA 1 decodes the RTS frame 320, it can know the communication duration of the OBSS, and STA 1 can perform communication on sub-channel 310 for the duration of the OBSS communication. Due to the difference in the reception time of the RTS frame 320 and the CTS frame 330, the operation time of AP 1 and STA 1 on sub-channel 310 can be different. For example, if AP 1 receives the RTS frame 320 of the OBSS and sends the frame to STA 1 on sub-channel 310 before the decoding or detection time of the CTS frame 330 on sub-channel 310 is completed, STA 1 will not be able to receive the frame. Therefore, if AP 1 decodes the RTS frame 320 and moves to sub-channel 310, it can delay frame transmission until the transmission completion time of the CTS frame 330 on the main channel 300. For example, AP 1's channel access operation (e.g., EDCA backoff operation) can be repeated until the transmission completion time of CTS frame 330. Alternatively, even if AP 1's channel access operation is successful (e.g., the EDCA backoff counter reaches 0), AP 1 can keep the backoff counter at 0 until the transmission completion time of CTS frame 330. AP 1 can send downlink frame 340 to STA 1 after the transmission completion time of CTS frame 330. AP 1 can send downlink frame 340 to STA 1 based on the transmission completion time of CTS frame 330. Alternatively, AP 1 can send downlink frame 340 to STA 1 after SIFS time following the transmission completion time of CTS frame 330, based on the transmission start time of data frame 350. STA 1, having received downlink frame 340, can send a response frame (e.g., block acknowledgment (BA) frame) to AP 1.On subchannel 310, communication between AP 1 and STA 1 can end within the communication duration of the OBSS. Aside from the difference in reception times for RTS and CTS frames, the frame reception times of AP 1 and STA 1 can differ from each other. For example, AP 1 may have already received the CTS frame of the OBSS, but STA 1 may not have received it yet. Conversely, STA 1 may not know the TXOP interval of the OBSS until the PHY preamble (e.g., L-SIG information, TXOP field, BSS color information) or MAC header of the OBSS data frame transmitted after the CTS frame is decoded. In this case, AP 1 may not transmit frames on the subchannel until STA 1 confirms the TXOP interval of the OBSS. That is, AP 1 can delay frame transmission until STA 1 confirms the communication duration of the OBSS and operates on the subchannel.

[0054] Figure 4 A third embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0055] refer to Figure 4 Wireless LAN terminals can operate on wireless LAN channels (e.g., 20MHz, 40MHz, 80MHz, 160MHz (or 80+80MHz), 320MHz channels). Wireless LAN terminals may include AP 1 and STA 1 associated with AP 1. Multiple wireless LAN terminals may be further associated with AP 1. Communication can be performed between AP 1 and the wireless LAN terminals associated with AP 1 using wireless LAN channels. Communication between wireless LAN terminals other than AP 1 and wireless LAN terminals associated with AP 1 can be referred to as Overlapping Basic Service Set (OBSS) communication. OBSS communication may cause interference to AP 1 and the wireless LAN terminals associated with AP 1.

[0056] In a wireless LAN channel, a primary channel 400 and a sub-channel 410 can be configured. The primary channel 400 and sub-channel 410 can be configured or negotiated between AP 1 and the wireless LAN terminals associated with AP 1. The primary channel 400 can be a channel that includes a primary 20MHz channel. Sub-channel 410 can be a channel that does not include the primary 20MHz channel. One or more sub-channels 410 can exist. For example, the wireless LAN channel can be 40MHz, the primary 20MHz channel can be the primary channel 400, and the non-primary 20MHz channel can be a sub-channel 410. As another example, the wireless LAN channel can be 80MHz, the primary channel 400 can be a 40MHz channel that includes the primary 20MHz channel, and the remaining 40MHz channel can be a sub-channel 410. Alternatively, the primary 20MHz channel can be the primary channel 400, and the remaining 20MHz channels can be three sub-channels 410. That is, the configuration of the primary channel 400 and sub-channel 410 can be configured in various ways. Sub-channel 410 can also be referred to as an "auxiliary main channel," "auxiliary channel," or "alternative channel." For example, in an 80MHz channel consisting of one main channel 400 and three sub-channels 410 as described above, the three sub-channels 410 can be referred to as three auxiliary main channels. The sub-channel 410 can be simply called sub-channel 410.

[0057] Figure 4 This is an implementation scheme for the presence of one main channel 400 and one sub-channel 410. However, this implementation scheme is not intended to limit operation to the presence of only one main channel 400 and one sub-channel 410, and it should be understood that wireless LAN terminals can operate in the same or similar manner as in this implementation scheme, even with various configurations of the main channel 400 and the sub-channel 410.

[0058] AP 1 and STA 1 can perform channel detection and / or channel access operations (e.g., EDCA backoff operation or backoff operation) on the main channel 400. STA 1 can detect and / or decode the OBSS RTS frame 420 on the main channel 400. When the energy of the RTS frame 420 is greater than or equal to an energy threshold, STA 1 can decode the RTS frame 420 or operate on the sub-channel 410. STA 1 can operate on the sub-channel based on the reception of the OBSS RTS frame, the OBSS CTS frame, and the OBSS data frame. For example, STA 1 can operate on the sub-channel based on the reception of the data frame's PHY preamble (e.g., L-SIG information, TXOP field, BSS color information) and / or MAC header. STA 1 can perform channel detection / channel access operations on sub-channel 410. If there is no transmission from AP 1 or the STA associated with AP 1 within a certain time period, STA 1 can operate on the main channel 400 again. The time period can be a preset value, a value broadcast by AP 1 via a beacon, or a value negotiated between STA 1 and AP 1. Alternatively, if STA 1 succeeds in a channel access operation (EDCA backoff operation) on sub-channel 410, it can send an RTS frame to AP 1. AP 1 may not respond to STA 1. If AP 1 does not respond to STA 1's RTS frame, STA 1 can operate again on main channel 400.

[0059] If STA 1 fails to decode the RTS frame 400, CTS frame, or data frame of OBSS on the main channel 400, and the detected energy is equal to or less than the energy threshold, then STA 1 may stop operating on the sub-channel 410 and may continue operating on the main channel 400.

[0060] Figure 5 A fourth embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0061] refer to Figure 5Wireless LAN terminals can operate on wireless LAN channels (e.g., 20MHz, 40MHz, 80MHz, 160MHz (or 80+80MHz), 320MHz channels). Wireless LAN terminals may include AP 1 and STA 1 associated with AP 1. Multiple wireless LAN terminals may be further associated with AP 1. Communication can be performed between AP 1 and the wireless LAN terminals associated with AP 1 using wireless LAN channels. Communication between wireless LAN terminals other than AP 1 and wireless LAN terminals associated with AP 1 can be referred to as Overlapping Basic Service Set (OBSS) communication. OBSS communication may cause interference to AP 1 and the wireless LAN terminals associated with AP 1.

[0062] In a wireless LAN channel, a primary channel 500 and sub-channels 511, 513, and 515 can be configured. The primary channel 500 and sub-channels 511, 513, and 515 can be configured or negotiated between AP 1 and the wireless LAN terminals associated with AP 1. The primary channel 500 can be a channel that includes a primary 20MHz channel. Sub-channels 511, 513, and 515 can be channels that do not include the primary 20MHz channel. At least one sub-channel 511, 513, or 515 can exist. For example, the wireless LAN channel can be 40MHz, the primary 20MHz channel can be the primary channel, and the non-primary 20MHz channels can be sub-channels. As another example, the wireless LAN channel can be 80MHz, the primary channel can be a 40MHz channel that includes the primary 20MHz channel, and the remaining 40MHz channels can be sub-channels. Alternatively, the primary 20MHz channel can be the primary channel, and the 20MHz channels other than the primary channel can be three sub-channels. In other words, the primary and sub-channel configurations can be configured in various ways. Sub-channels 511, 513, and 515 can also be referred to as “auxiliary main channels,” “auxiliary channels,” or “alternative channels.” For example, in an 80MHz channel consisting of one main channel 500 and three sub-channels 511, 513, and 515 as described above, the three sub-channels 511, 513, and 515 can be referred to as three auxiliary main channels.

[0063] Figure 5 This is an implementation scheme for the presence of one main channel 500 and three sub-channels 511, 513, and 515. However, this implementation scheme is not intended to limit operation to the presence of only one main channel and three sub-channels, and it should be understood that wireless LAN terminals can operate in the same or similar manner as in this implementation scheme, even with various configurations of the main channel and sub-channels.

[0064] AP 1 and STA 1 can perform channel detection and / or channel access operations (e.g., EDCA backoff operation or backoff operation) on the main channel 500. AP 1 can detect and decode the RTS frames of the OBSS on the main channel 500 and identify the communication duration of the OBSS. The communication duration of the OBSS can be identified by information in the duration field present in the MAC header of the RTS frame and / or information included in the PHY preamble of the RTS frame (e.g., L-SIG information, etc.). Conversely, the communication duration of the OBSS identified from the RTS frame can be confirmed simply by receiving the CTS frame transmitted after the RTS frame. In addition to the RTS frame, the communication duration of the OBSS can be confirmed by receiving the CTS frame, the PHY preamble (e.g., L-SIG information, TXOP field, BSS color information), or the MAC header. Here, the PHY preamble and the MAC header can be included in the data frame of the OBSS. AP 1 can operate on sub-channels 511, 513, and 515 during the communication duration of the OBSS. The duration of OBSS communication is referred to as the "subchannel communication possible interval" or "communication possible interval". STA 1 can also decode RTS frames in the same way as AP 1. Alternatively, STA 1 can detect the energy of the RTS frame, and the detected energy can be greater than or equal to an energy threshold. Accordingly, STA 1 can operate on subchannels 511, 513, and 515. When OBSS is using the main channel 500, AP 1 and STA 1 may have negotiated a process of operating in the order of subchannel 1 511, subchannel 2 513, and subchannel 3 515. The subchannel numbering can be sequential 20MHz channels extending from the main channel, such as 40MHz, 80MHz, etc. Depending on the negotiation process, AP 1 and STA 1 can operate on subchannel 1 511. However, subchannel 1 511 may be busy. Subchannel 1 511 may be busy due to OBSS or non-802.11 (non-WLAN) communication. When subchannel 1 511 is busy for a certain period of time, AP 1 and STA 1 can operate on subchannel 2 513. For example, the certain period of time could be the priority interframe space (PIFS). AP 1 and STA 1 may not know the communication duration of subchannel 1 511 and can perform communication for possible communication intervals confirmed in the main channel 500. If AP 1 or STA 1 does not know the possible communication intervals, it can obtain the possible communication interval information through the RTS frame and CTS frame exchange process, in which settings are configured... Figure 3The specific values ​​are the same or similar to those in the implementation scheme. Subchannel 3 515, which is a subchannel adjacent to subchannel 2 513, can be used for communication together with subchannel 2 513 during a specific period of channel idle time (e.g., the priority inter-frame interval (PIFS) time).

[0065] Figure 6 A fifth embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0066] refer to Figure 6 Wireless LAN terminals can operate on wireless LAN channels (e.g., 20MHz, 40MHz, 80MHz, 160MHz (or 80+80MHz), 320MHz channels). Wireless LAN terminals may include AP 1 and STA 1 associated with AP 1. Multiple wireless LAN terminals may be further associated with AP 1. Communication can be performed between AP 1 and the wireless LAN terminals associated with AP 1 using wireless LAN channels. Communication between wireless LAN terminals other than AP 1 and wireless LAN terminals associated with AP 1 can be referred to as Overlapping Basic Service Set (OBSS) communication. OBSS communication may cause interference to AP 1 and the wireless LAN terminals associated with AP 1.

[0067] In a wireless LAN channel, a primary channel and sub-channels can be configured. The primary and sub-channels can be configured or negotiated between AP 1 and the wireless LAN terminals associated with AP 1. The primary channel can be a channel that includes a primary 20MHz channel. Sub-channels can be channels that do not include the primary 20MHz channel. At least one sub-channel can exist. For example, the wireless LAN channel can be 40MHz, the primary 20MHz channel can be the primary channel, and the non-primary 20MHz channel can be a sub-channel. As another example, the wireless LAN channel can be 80MHz, the primary channel can be a 40MHz channel that includes the primary 20MHz channel, and the remaining 40MHz channel can be a sub-channel. Alternatively, the primary 20MHz channel can be primary channel 600, and the 20MHz channels other than primary channel 600 can be three sub-channels 611, 613, and 615. That is, the configuration of the primary and sub-channels can be in various forms. Sub-channels can also be referred to as "auxiliary primary channel," "auxiliary channel," "secondary channel," or "alternative channel." For example, in an 80MHz channel consisting of a main channel 600 and three sub-channels 611, 613 and 615 as described above, the three sub-channels 611, 613 and 615 can be referred to as three auxiliary main channels.

[0068] Figure 6This is an implementation scheme for the presence of one main channel 600 and three sub-channels 611, 613, and 615. However, this implementation scheme is not intended to limit operation to the presence of only one main channel 600 and three sub-channels 611, 613, and 615, and it should be understood that wireless LAN terminals can operate in the same or similar manner as in this implementation scheme, even with various configurations of the main channel and sub-channels.

[0069] In AP 1 and STA 1, the channel access parameters for the main channel 600 and sub-channels 611, 613, and 615 can be managed independently. For example, the channel access parameters CW[AC] and QSRC[AC] of the main channel 600 can be managed differently in sub-channels 611, 613, and 615. The channel access parameters for sub-channels 611, 613, and 615 can be managed multiple times, as many times as there are sub-channels 611, 613, and 615, or multiple sub-channels 611, 613, and 615 can use common channel access parameters. The channel access parameters for the main channel 600 and the sub-channels 611, 613, and 615 can be linked or not linked. When the channel access parameters are not linked, the channel access parameters for the main channel 600 and the sub-channels 611, 613, and 615 operate completely independently.

[0070] When channel access parameters are linked, the following operations can be performed, for example: If data related to a specific AC is successfully transmitted on sub-channels 611, 613, and 615, the EDCA parameters related to the corresponding AC can be initialized in the main channel 600. For example, CW[AC] and QSRC[AC] of the main channel 600 can be initialized.

[0071] If no data related to a specific AC is transmitted on sub-channels 611, 613, and 615, EDCA parameters related to the corresponding AC can be added to the main channel 600. For example, CW[AC] and QSRC[AC] of the main channel 600 can be added. Even if the channel access parameters of the main channel 600 and sub-channels 611, 613, and 615 are linked, some parameters may not be linked. For example, even if transmission fails on the main channel 600, the QSRC[AC] parameter of the sub-channels 611, 613, and 615 may not be added.

[0072] Alternatively, the channel access parameters for sub-channels 611, 613, and 615 can be one-time events. For example, when an AP and STA operating on the main channel 600 move to and operate on sub-channels 611, 613, and 615, the AP and STA can choose the channel access parameters to use on sub-channels 611, 613, and 615, and based on the selected channel access parameters, the AP and STA can perform frame transmissions on sub-channels 611, 613, and 615. When the AP or STA moves back from sub-channels 611, 613, and 615 to the main channel 600, the channel access parameters for sub-channels 611, 613, and 615 can be discarded, regardless of whether the transmissions on sub-channels 611, 613, and 615 were successful or failed. Below is an example of a channel access parameter management method.

[0073] AP 1 and STA 1 can perform channel detection and / or channel access operations on the main channel 600. For example, channel access operations include EDCA backoff and backoff operation 630. AP 1 can detect and decode the RTS frame 620 of the OBSS on the main channel 600 and identify the communication duration of the OBSS. The communication duration of the OBSS can be identified by information in the duration field present in the MAC header of the RTS frame 620 and / or by information included in the PHY preamble of the RTS frame 620 (e.g., L-SIG information, etc.). Conversely, the communication duration of the OBSS identified from the RTS frame can be confirmed simply by receiving the CTS frame transmitted after the RTS frame. In addition to the RTS frame, the communication duration of the OBSS can be confirmed by receiving the CTS frame, the PHY preamble (e.g., L-SIG information, TXOP field, BSS color information), or the MAC header. Here, the PHY preamble and MAC header can be included in the OBSS data frame. AP 1 can operate on sub-channels 611, 613, and 615 during the communication duration of the OBSS. The communication duration of the OBSS is referred to as the "sub-channel communication possible interval" or "communication possible interval". STA 1 can also decode RTS frame 620 in the same manner as AP 1. Alternatively, STA 1 can detect the energy of RTS frame 620, and the detected energy can be greater than or equal to an energy threshold. Accordingly, STA 1 can operate on sub-channels 611, 613, and 615. When the OBSS is using the main channel 600, AP 1 and STA 1 may have negotiated a process of operating in the order of sub-channel 1 611, sub-channel 2 613, and sub-channel 3 615. In at least one of sub-channels 1 611, 2 613, and 3 615, the transmission operation of AP 1 and / or STA 1 may have failed, and AP 1 and STA 1 can then operate again on the main channel 600. If transmission fails on sub-channels 611, 613, and 615, channel access can be performed again on the main channel 600. For example, the EDCA backoff counter 640 of AP 1 or / and STA 1 can reuse the backoff counter 630 used on the main channel 600 before moving to sub-channels 611, 613, and 615. Alternatively, the EDCA backoff counter 640 of AP 1 or / and STA 1 can be reselected using existing EDCA backoff parameters used on the main channel 600, or it can be reselected using initialized EDCA backoff parameters (e.g., CW[AC] equals CWmin[AC], QSRC[AC] equals 0).Alternatively, for fairness in the event of a collision due to transmission failures in sub-channels 611, 613, and 615, the backoff counter 640 of the main channel 600 can be reselected using EDCA backoff parameters increased from those used in the main channel 600 (e.g., CW[AC] is doubled and QSRC[AC] is increased by 1).

[0074] Figure 7 A sixth embodiment of a communication method utilizing a sub-channel of a wireless local area network terminal is shown.

[0075] refer to Figure 7 Wireless LAN terminals can operate on wireless LAN channels (e.g., 20MHz, 40MHz, 80MHz, 160MHz (or 80+80MHz), 320MHz channels). Wireless LAN terminals may include AP 1 and STA 1 associated with AP 1. Multiple wireless LAN terminals may be further associated with AP 1. Communication can be performed between AP 1 and the wireless LAN terminals associated with AP 1 using wireless LAN channels. Communication between wireless LAN terminals other than AP 1 and wireless LAN terminals associated with AP 1 can be referred to as Overlapping Basic Service Set (OBSS) communication. OBSS communication may cause interference to AP 1 and the wireless LAN terminals associated with AP 1.

[0076] In a wireless LAN channel, a primary channel and sub-channels can be configured. The primary and sub-channels can be configured or negotiated between AP 1 and the wireless LAN terminals associated with AP 1. The primary channel can be a channel that includes a primary 20MHz channel. Sub-channels can be channels that do not include the primary 20MHz channel. At least one sub-channel can exist. For example, the wireless LAN channel can be 40MHz, the primary 20MHz channel can be the primary channel, and the non-primary 20MHz channel can be a sub-channel. As another example, the wireless LAN channel can be 80MHz, the primary channel can be a 40MHz channel that includes the primary 20MHz channel, and the remaining 40MHz channel can be a sub-channel. Alternatively, the primary 20MHz channel can be the primary channel, and the non-primary 20MHz channel can be three sub-channels. In other words, the configuration of the primary and sub-channels can take various forms. Sub-channels can also be referred to as "auxiliary primary channel," "auxiliary channel," "secondary channel," or "alternative channel." For example, in an 80MHz channel consisting of a main channel 700 and three sub-channels 711, 713 and 715 as described above, the three sub-channels 711, 713 and 715 can be referred to as three auxiliary main channels.

[0077] Figure 7This is an implementation scheme for the presence of one main channel 700 and three sub-channels 711, 713, and 715. However, this implementation scheme is not intended to limit operation to the presence of only one main channel 700 and three sub-channels 711, 713, and 715, and it should be understood that wireless LAN terminals can operate in the same or similar manner as in this implementation scheme, even with various configurations of the main channel and sub-channels.

[0078] In AP 1 and STA 1, the channel access parameters for the main channel 700 and sub-channels 711, 713, and 715 can be managed independently. Here, channel access parameters include backoff parameters. For example, the channel access parameters CW[AC] and QSRC[AC] for the main channel 700 can be managed differently in sub-channels 711, 713, and 715. The channel access parameters for sub-channels 711, 713, and 715 can be managed multiple times, as many times as there are sub-channels 711, 713, and 715, and multiple sub-channels 711, 713, and 715 can use common channel access parameters. The channel access parameters for the main channel 700 and the sub-channels 711, 713, and 715 can be linked or not linked. When the channel access parameters are not linked, the channel access parameters for the main channel 700 and the sub-channels 711, 713, and 715 operate completely independently.

[0079] When the channel access parameters are linked, the following operations can be performed. If data related to a specific AC is successfully transmitted on sub-channels 711, 713, and 715, the EDCA parameters related to the corresponding AC can be initialized in the main channel 700. For example, CW[AC] and QSRC[AC] of the main channel 700 can be initialized.

[0080] If no data related to a specific AC is transmitted on sub-channels 711, 713, and 715, EDCA parameters related to the corresponding AC can be added to the main channel 700. For example, CW[AC] and QSRC[AC] of the main channel 700 can be added. Even if the channel access parameters of the main channel 700 and sub-channels 711, 713, and 715 are linked, some parameters may not be linked. For example, even if data transmission fails on the main channel 700, the QSRC[AC] parameter of the sub-channels 711, 713, and 715 may not be added.

[0081] Alternatively, the channel access parameters for sub-channels 711, 713, and 715 can be one-time events. For example, when an AP and STA operating on the main channel 700 move to and operate on sub-channels 711, 713, and 715, they can select the channel access parameters to use on sub-channels 711, 713, and 715, and perform frame transmissions on these sub-channels based on the selected parameters. When returning to the main channel 700 from sub-channels 711, 713, and 715, the AP and STA can discard the channel access parameters for sub-channels 711, 713, and 715, regardless of whether the transmissions on these sub-channels were successful or failed. An example of a channel access parameter management method is given below.

[0082] AP 1 and STA 1 can perform channel detection and / or channel access operation 730 on the main channel 700. For example, channel access operation 730 includes at least one of EDCA backoff operation or backoff operation. AP 1 can detect and decode the RTS frame 720 of the OBSS on the main channel 700 and identify the communication duration of the OBSS. The communication duration of the OBSS can be identified by information in the duration field present in the MAC header of the RTS frame 720 and / or information included in the PHY preamble of the RTS frame 720 (e.g., L-SIG information, etc.). Conversely, the communication duration of the OBSS identified from the RTS frame can be confirmed simply by receiving the CTS frame transmitted after the RTS frame. In addition to the RTS frame, the communication duration of the OBSS can be confirmed by receiving the CTS frame, the PHY preamble (e.g., L-SIG information, TXOP field, BSS color information), or the MAC header. Here, the PHY preamble and the MAC header can be included in the data frame of the OBSS. AP 1 can operate on sub-channels 711, 713, and 715 during the communication duration of the OBSS. The communication duration of the OBSS is referred to as the "sub-channel communication possible interval" or "communication possible interval". STA 1 can also decode RTS frame 720 in the same manner as AP 1. Alternatively, STA 1 can detect the energy of RTS frame 720, and the detected energy can be equal to or greater than an energy threshold. Therefore, STA 1 can operate on sub-channels 711, 713, and 715. When the OBSS is using the main channel 700, AP 1 and STA 1 may have negotiated a process of operating in the order of sub-channel 1 711, sub-channel 2 713, and sub-channel 3 715. In at least one of sub-channels 1 711, 2 713, and 3 715, the transmission operation of AP 1 and / or STA 1 may have been successful, and AP 1 and STA 1 can operate again on the main channel 700. On the main channel 700, channel access operation 740 can be performed again. Since frames have already been transmitted on the main channel 700, for fairness, the backoff counter 740 can be reselected in the main channel 700. Before moving to sub-channels 711, 713, and 715, the backoff counter 740 for AP 1 and / or STA 1 can be selected using the EDCA backoff parameters used in the main channel 700. Alternatively, the backoff counter 740 for AP 1 and / or STA 1 can be reselected using one of the increased EDCA backoff parameters compared to the EDCA backoff parameters used in the main channel 700 (e.g., CW[AC] is increased by a factor of 2, and QSRC[AC] is increased by 1) or the initialized EDCA backoff parameters (e.g., CW[AC] equals CWmin[AC], and QSRC[AC] equals 0).Alternatively, if the backoff counter 730 used in the primary channel 700 of AP 1 or / and STA 1 is greater than or equal to a certain value, AP 1 or / and STA 1 can perform channel access without reselecting the backoff counter 740 on the primary channel 700.

[0083] The following describes, exemplarily, a communication method utilizing sub-channels according to an embodiment of the present invention. The communication method utilizing sub-channels is performed by an AP and a STA. An STA may be an STA associated with an AP. When the primary channel is in use, the AP and STA may utilize at least one sub-channel to perform communication. That is, when the primary channel is in use, the STA and AP can perform communication by switching to a sub-channel. In other words, the STA and AP may temporarily use a sub-channel as the primary channel. In other words, a sub-channel can be used as an alternative or substitute for the primary channel. The operation of switching a channel to a sub-channel may be referred to as sub-channel connection, channel switching, sub-channel switching, or channel reversal. The operation of switching a channel from a sub-channel to the primary channel may be referred to as channel reversal. A sub-channel may be a channel in a neighboring frequency band. A sub-channel may refer to a channel in the remaining frequency band of the entire channel band excluding the primary channel band.

[0084] Figure 8 An embodiment of a method for operating a STA according to an embodiment of the present invention is shown. Figure 8 An implementation scheme for operating a STA associated with an AP is shown. The STA can send or receive data.

[0085] refer to Figure 8 In step S801, the STA detects whether another device is performing communication. Here, the other device refers to a device other than the STA and the AP associated with the STA. The communication of the other device can be called OBSS communication. The STA can detect whether OBSS communication is performed using frames transmitted during OBSS communication. For example, the STA can detect the RTS frame of OBSS communication (e.g., Figure 3 OBSS communication can be identified by detecting the energy of the RTS frame (320) of OBSS communication. As another example, the STA can also identify OBSS communication by detecting the energy of the CTS frame (e.g., ). Figure 3 OBSS communication can be identified by the energy of the CTS frame 330. As another example, the STA can identify OBSS communication by decoding the frame of the OBSS communication. The STA can obtain information about the duration of the OBSS communication. The duration of the OBSS communication refers to the time interval during which the OBSS communication is performed. Information about the duration of the communication can be obtained from the AP. Alternatively, it can be based on the frame transmitted in the OBSS communication (e.g., ...). Figure 3The STA can obtain information about the duration of OBSS communication by using the RTS frame 320. If information about the duration of OBSS communication cannot be obtained, the STA may not perform steps S803 and below.

[0086] In step S803, the STA switches the working channel from the primary channel (e.g., Figure 3 The main channel 300 is switched to at least one sub-channel (e.g., Figure 3 Sub-channel 310). Here, the working channel is the channel used for communication between the AP and STA. The STA can switch the working channel to a sub-channel adjacent to the main channel. Here, a sub-channel adjacent to the main channel means a sub-channel whose frequency band is adjacent to the main channel. If a sub-channel adjacent to the main channel is busy, the STA can switch the channel to another sub-channel. For example, the STA can switch the channel to a busy sub-channel (e.g., Figure 5 Sub-channel 1 511) neighboring sub-channels (e.g., Figure 5 (Sub-channel 2 513). The STA can switch the channel to at least one idle sub-channel. In other words, the STA can switch the channel to at least one sub-channel, which includes the sub-channel with the frequency band closest to the main channel among the non-busy sub-channels.

[0087] In step S805, the STA performs transmission or reception on the sub-channel. The STA determines the transmission time point for performing the transmission. The transmission time point may be, for example, the time when both the STA and the AP switch their operating channels to the sub-channel. The STA performs a channel access procedure to perform the transmission. The channel access procedure may be, for example, an EDCAF backoff procedure. The sub-channel channel access procedure may be performed based on at least one of the sub-channel channel access parameters or the main channel channel access parameters. The channel access parameters include backoff parameters. The sub-channel channel access parameters may be linked to the main channel channel access parameters. Alternatively, the sub-channel channel access parameters and the main channel channel access parameters may be independent. After the channel access procedure is successful, the STA may wait until both the AP and the STA switch their channels to the sub-channel, or it may retry the channel access procedure. That is, after both the AP and the STA switch their channels to the sub-channel, the STA may transmit data. For this purpose, the STA may predict the AP's channel switching time. For example, the STA may predict the AP's channel switching time based on the time when the CTS frame transmission is completed. After the channel access procedure is successful, the STA sends data to the AP. Data transmission may succeed. Alternatively, data transmission may fail. If no frame is received from the AP within a specific time period, the STA executes step S807. Here, the specific time period can be defined through negotiation between the AP and the STA, broadcast by the AP, or it can be a predefined value.

[0088] In step S807, the STA returns to the primary channel. In other words, the STA switches the channel from the sub-channel to the primary channel. The STA switches the channel to the primary channel before the end of the OBSS communication duration. The STA can perform a channel access procedure (e.g., Figure 6 The channel access procedure 640 is used for transmission on the primary channel. The channel access parameters of the primary channel and the channel access parameters of the sub-channels may not be linked. Alternatively, the channel access parameters of the primary channel and the channel access parameters of the sub-channels may be linked. For example, if data transmission on the sub-channel is successful, the channel access parameters of the primary channel may be changed. Compared to the channel access parameters previously used on the primary channel, the channel access parameters of the primary channel may have increased, decreased, or initialized values. As another example, if data transmission on the sub-channel fails, the channel access parameters of the primary channel may be changed based on the channel access parameters of the sub-channel. Compared to the channel access parameters previously used on the primary channel, the channel access parameters of the primary channel may have increased, decreased, or initialized values.

[0089] Figure 9 An embodiment of a method for operating an AP according to an embodiment of the present invention is shown. Figure 9 An implementation scheme for a method of operating an AP associated with an AP is shown. The AP can send or receive data.

[0090] refer to Figure 9 In step S901, the AP detects whether another device is occupying the main channel. Here, "another device" refers to a device other than the AP and the STA associated with the AP. Another device occupying the main channel indicates that the other device is performing communication on the main channel. This communication by the other device can be referred to as OBSS communication. The AP can detect whether OBSS communication is being performed using frames transmitted during OBSS communication. For example, the AP can detect the RTS frames of OBSS communication (e.g., ...). Figure 3 OBSS communication can be identified by detecting the energy of the RTS frame (320) of OBSS communication. As another example, the AP can identify OBSS communication by detecting the energy of the CTS frame (e.g., RTS frame 320). Figure 3 The energy of the CTS frame (330) can be used to identify OBSS communication. As another example, the AP can identify OBSS communication by decoding the frames of the OBSS communication. The AP can obtain information about the duration of the OBSS communication. The duration of the OBSS communication refers to the time period during which the OBSS communication is performed. Information about the duration of the OBSS communication can be obtained from the AP. Alternatively, information about the duration of the OBSS communication can be obtained based on the frames transmitted during the OBSS communication. If information about the duration of the OBSS communication cannot be obtained, the AP may not perform step S903 and below.

[0091] In step S903, the AP switches the working channel from the primary channel (e.g., Figure 3 The main channel 300 is switched to at least one sub-channel (e.g., Figure 3 Sub-channel 310). Here, the working channel is the channel used by the AP and STA for communication. The AP can switch the working channel to a sub-channel adjacent to the main channel. Here, a sub-channel adjacent to the main channel means a sub-channel whose frequency band is adjacent to the main channel. If a sub-channel adjacent to the main channel is busy, the AP can switch the channel to another sub-channel. For example, the AP can switch the channel to a busy sub-channel (e.g., Figure 5 Sub-channel 1 511 (e.g., Figure 5 (2513) Neighboring sub-channels. The AP can switch the channel to at least one idle sub-channel. In other words, the AP can switch the channel to at least one sub-channel, which includes the sub-channel with the frequency band closest to the main channel among the non-busy sub-channels.

[0092] In step S905, the AP performs transmission or reception on the sub-channel. The AP determines the transmission time point for performing the transmission. The transmission time point may be, for example, the time when both the STA and the AP switch their operating channels to the sub-channel. The AP performs a channel access procedure to perform the transmission. The channel access procedure may be, for example, an EDCAF backoff procedure. The sub-channel channel access procedure may be performed based on at least one of the sub-channel channel access parameters or the main channel channel access parameters. The channel access parameters include backoff parameters. The sub-channel channel access parameters may be linked to the main channel channel access parameters. Alternatively, the sub-channel channel access parameters and the main channel channel access parameters may be independent. After the channel access procedure is successful, the AP may wait until both the AP and the STA switch to the sub-channel, or it may retry the channel access procedure. In other words, the AP may transmit data after both the AP and the STA have switched their channels to the sub-channel. To this end, the AP may predict the STA's channel switching time. For example, the AP may predict the STA's channel switching time based on the time when the CTS frame transmission is completed. After the channel access procedure is successful, the AP sends data to the STA. Data transmission may be successful. Alternatively, data transmission may fail. If no frame is received from the AP within a specific time period, the AP executes step S907. Here, the specific time period can be defined through negotiation between the AP and the STA, broadcast by the AP, or it can be a predefined value.

[0093] In step S907, the AP returns the working channel to the primary channel. In other words, the AP switches from the sub-channel to the primary channel. The AP switches the channel to the primary channel before the end of the OBSS communication duration. The AP can perform a channel access procedure (e.g., Figure 6 The channel access procedure 640 is used for transmission on the primary channel. The channel access parameters of the primary channel and the channel access parameters of the sub-channels may not be linked. Alternatively, the channel access parameters of the primary channel and the channel access parameters of the sub-channels may be linked. For example, if data transmission on the sub-channel is successful, the channel access parameters of the primary channel may be changed. Compared to the channel access parameters previously used on the primary channel, the channel access parameters of the primary channel may have increased, decreased, or initialized values. As another example, if data transmission on the sub-channel fails, the channel access parameters of the primary channel may be changed based on the channel access parameters of the sub-channel. Compared to the channel access parameters previously used on the primary channel, the channel access parameters of the primary channel may have increased, decreased, or initialized values.

[0094] The operation of the method according to an exemplary embodiment of the present invention can be implemented as a computer-readable program or code in a computer-readable recording medium. The computer-readable recording medium may include all types of recording means for storing data that can be read by a computer system. Furthermore, the computer-readable recording medium can store and execute programs or code that can be distributed across computer systems connected via a network and read in a distributed manner by a computer.

[0095] Additionally, computer-readable recording media may include hardware devices specifically configured to store and execute program commands, such as ROM, RAM, or flash memory. Program commands may include not only machine language code created by a compiler but also high-level language code that can be executed by a computer using an interpreter.

[0096] Although the invention has been described with reference to preferred embodiments thereof, those skilled in the art will understand that various modifications and alterations may be made to the invention without departing from the scope and spirit of the invention as defined by the appended claims.

[0097] Industrial availability This disclosure can be used in devices and recording media in wireless local area network systems.

Claims

1. A method for operating an access point (AP) in a wireless local area network system, the method comprising: It was detected that a device other than at least one station (STA) associated with the AP was communicating on the main channel; Obtain information related to the duration of the communication; During the duration, the working channel is switched from the main channel to at least one sub-channel; Sending or receiving data on a sub-channel; as well as Switch the working channel to the main channel.

2. The method of claim 1, further comprising determining the transmission time point for transmitting or receiving data on the sub-channel.

3. The method according to claim 2, in, The transmission time point is determined based on whether the AP and at least one STA switch their working channels.

4. The method according to claim 2, in, The transmission time point is determined based on the time point at which at least one STA switches its working channel.

5. The method according to claim 2, wherein, Sending or receiving includes performing a channel access procedure for transmission on a sub-channel.

6. The method according to claim 4, in, If the channel access procedure is completed before the transmission time point, the channel access procedure is repeated until the transmission time point.

7. The method according to claim 1, wherein, Whether to perform communication is determined based on the amount of energy in the frames used for communication.

8. The method according to claim 1, in, Information about the duration is obtained from the STA or by decoding the frames used for communication.

9. The method according to claim 1, in, During the specified duration, the working channel will be switched to the primary channel.

10. A method for use as a station (STA) in a wireless local area network system, the method comprising: Devices other than the access point (AP) associated with the STA were detected communicating on the main channel; Obtain information related to the duration of the communication; During the duration, the working channel is switched from the main channel to at least one sub-channel; Sending or receiving data on a sub-channel; as well as Switch the working channel to the main channel.

11. The method of claim 10, further comprising determining a transmission time point for transmitting or receiving data on a sub-channel.

12. The method according to claim 11, in, The transmission time point is determined based on whether the STA and AP switch their working channels.

13. The method according to claim 11, in, The transmission time point is determined based on the time point at which at least one STA switches its working channel.

14. The method according to claim 12, wherein, Sending or receiving includes performing a channel access procedure for transmission on a sub-channel.

15. The method according to claim 13, in, If the channel access procedure is completed before the transmission time point, the channel access procedure is repeated until the transmission time point.

16. The method of claim 10, wherein, Whether to perform communication is determined based on the amount of energy in the frames used for communication.

17. The method according to claim 10, in, Information about the duration is obtained from the AP or by decoding the frames used for communication.

18. The method according to claim 10, in, During the specified duration, the working channel will be switched to the primary channel.

19. An access point (AP) in a wireless local area network system, the AP comprising: transceiver; and The processor, which is connected to the transceiver, The processor is configured as follows: It was detected that a device other than at least one station (STA) associated with the AP was communicating on the main channel; Obtain information related to the duration of the communication; During the duration, the working channel is switched from the main channel to at least one sub-channel; To send or receive data on a sub-channel; and Switch the working channel to the main channel.

20. A station (STA) in a wireless local area network system, the STA comprising: transceiver; and The processor, which is connected to the transceiver, The processor is configured as follows: Devices other than the access point (AP) associated with the STA were detected communicating on the main channel; Obtain information related to the duration of the communication; During the duration, the working channel is switched from the main channel to at least one sub-channel; To send or receive data on a sub-channel; and Switch the working channel to the main channel.

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