A non-primary channel access method in a wireless local area network and related apparatus

Abstract

The application provides a non-primary channel access method and related device in a wireless local area network, and relates to data communication between an AP and one or more STAs, and is also applicable to communication between APs and communication between STAs. The application improves the consistency of switching to a slave channel when the AP and the STA perform NPCA, that is, the AP is prevented from working on the primary channel and the STA is switched to work on the slave channel. Therefore, the number of retransmissions is reduced, the packet loss rate of transmission is lowered, and the service quality is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wireless communication, and in particular to a non-primary channel access method and related apparatus. BACKGROUND

[0002] WLAN refers to a wireless network covering a local area, and its typical representative is Wi-Fi. Due to the characteristics of high transmission rate, low cost and open use, WLAN has attracted extensive attention from the industry and academia. WLAN works in the unlicensed spectrum, and its most famous and dominant international standard is IEEE 802.11. Since the first version was released in 1997, IEEE 802.11 has experienced major standard evolution versions such as 802.11, 802.11a and 802.11b, 802.11g, 802.1n, 802.11ac, 802.11ax (considered as the sixth generation of Wi-Fi, Wi-Fi 6), and the latest generation of WLAN standard IEEE 802.11be (considered as the seventh generation of Wi-Fi, Wi-Fi 7) will be officially released in 2024 or 2025. The next generation of WLAN standard IEEE 802.11bn (considered as the eighth generation of Wi-Fi, Wi-Fi 8) has also begun to be studied and is planned to be released in 2028. WLAN carries more than 50% of the global Internet Protocol (IP) traffic, and has become the main wireless network together with the cellular network at present and in the future.

[0003] WLAN has various network structures, and a commonly used structure is described as shown in Figure 1 A WLAN is composed of one or more basic service sets (BSSs). The concept of BSS is close to that of a cell. Each BSS is composed of an access point (AP) and one or more non-AP stations (non-AP STAs). For example, an access point is generally implemented in a wireless router, and a non-AP STA is generally implemented in a terminal device such as a smart phone. Generally, all uplink services are sent from a non-AP STA to an AP, and all downlink services are sent from an AP to a non-AP STA. Stations located in the same BSS are referred to as an intra-BSS or an intra-cell, and stations located in different BSSs are referred to as an inter-BSS or an inter-cell. An AP located in the same BSS as any non-AP STA is referred to as an associated AP of the non-AP STA, and the non-AP STA is referred to as an associated STA of the AP.

[0004] non-AP STA, is called Point-to-Point (P2P), and a Station includes both AP and non-AP STA.

[0005] Physical layer packet format and principle of Network Allocation Vector (NAV)

[0006] The physical layer packet transmitted by a Station (AP or non-AP STA) over the air interface is called Physical Layer Protocol Data Unit (PPDU), which is the packet sent by each node over the air interface through the physical layer. PPDU is understood as an air interface data packet. The PPDU includes a preamble and a payload part. The Network Allocation Vector (NAV) can be contained in the preamble or payload part of the PPDU. The NAV is a time length, indicating the remaining time length that the transmitting station of the PPDU still needs to occupy the channel from the end time of the PPDU.

[0007] When any Station receives a PPDU, if it is determined that the PPDU is from the BSS (i.e. the cell), and the end time of the NAV carried by the PPDU exceeds the end time of the intra-BSS NAV recorded by the Station, the intra-BSS NAV needs to be updated so that the end time of the intra-BSS NAV is consistent with the end time of the NAV carried by the received PPDU.

[0008] When any Station receives a PPDU, if it is determined that the PPDU is from the BSS (i.e. the cell), and the end time of the NAV carried by the PPDU exceeds the end time of the intra-BSS NAV recorded by the Station, the intra-BSS NAV needs to be updated so that the end time of the intra-BSS NAV is consistent with the end time of the NAV carried by the received PPDU.

[0009] Channel access of WLAN

[0010] Channel access refers to the process by which nodes in a network acquire the right to use a channel. Since WLANs operate in unlicensed spectrum, this means that various wireless systems can publicly and freely use this spectrum resource, necessitating contention-based channel access. Specifically, IEEE 802.11 specifies that nodes in WLANs should use Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA). The CSMA / CA mechanism uses a Listen Before Talk (LBT) approach to access the channel; that is, a node wishing to acquire channel access for frame exchange must first listen to the channel's availability level. Only when the channel is idle and certain rules are met can the node acquire channel access.

[0011] WLAN multi-channel mechanism

[0012] In a WLAN, the bandwidth of a single channel is 20MHz. A node can occupy multiple channels during transmission to create a larger bandwidth; that is, a node's transmission bandwidth can be composed of several channels with a bandwidth of 20MHz. For example... Figure 2 In (a), the transmission bandwidth of the node is 160MHz, which consists of eight 20MHz channels. Figure 2 As shown in (b), among all channels within the available bandwidth, one channel is called the Primary Channel (PCH), and all other channels are called Secondary Channels (SCH). The existing 802.11 specification stipulates that nodes must ensure the Primary Channel is idle and available during channel access and transmission; otherwise, if the Primary Channel is busy, channel access and transmission are not allowed even if a large number of Secondary Channels are idle. This results in a waste of resources, and therefore, the next-generation WLAN aims to find a method to improve resource utilization. Summary of the Invention

[0013] To overcome the shortcomings of the prior art, the present invention provides a non-master channel access method and related apparatus in a wireless local area network, which relates to data communication between an AP and one or more STAs, and is also applicable to communication between APs and between STAs.

[0014] The technical solution adopted by this invention to solve its technical problem is:

[0015] In a first aspect, the application provides a non-primary channel access method in a wireless local area network. When the intra-BSS NAV of a station is not 0, the station is not allowed to switch to a secondary channel according to NPCA. The method comprises the following steps:

[0016] Step 1: When the first station receives a first PPDU, the first station determines whether the PPDU is from an external BSS according to the BSS color field in the preamble of the PPDU or an address field in a MAC frame carried by the PPDU. If the PPDU is from an external BSS, the process proceeds to step 2. If the PPDU is not from an external BSS, the process ends.

[0017] Step 2: The first station determines whether the intra-BSS NAV of the first station is 0. If the intra-BSS NAV is not 0, the process proceeds to step 3. If the intra-BSS NAV is 0, the process proceeds to step 4.

[0018] Step 3: The first station is not allowed to perform NPCA according to the received first PPDU, i.e., the first station is not allowed to switch to a secondary channel after receiving the first PPDU. The process ends.

[0019] Step 4: If the first station satisfies a first condition, the first station is allowed to perform NPCA according to the received first PPDU. If the first station does not satisfy the first condition, the first station is not allowed to perform NPCA according to the received first PPDU.

[0020] Further, the first condition is that the duration of the NAV carried in the first PPDU is greater than or equal to a first threshold. The first threshold is a preset duration, and the application takes 2 ms as the value of the first threshold.

[0021] In a second aspect, the application provides a non-primary channel access method in a wireless local area network. The method allows the use of NPCA, i.e., enables NPCA, i.e., allows a station to switch to a secondary channel according to the principle of NPCA. The method does not allow the use of NPCA, i.e., disables NPCA, i.e., does not allow a station to switch to a secondary channel according to the principle of NPCA. The method comprises the following steps:

[0022] Step 1: The second station receives a first frame sent by a first AP, and parses an allocation time of a transmission opportunity sharing from the first frame.

[0023] The first AP is an associated AP of the second station.

[0024] The first frame is used to indicate that the first AP shares the first AP transmission opportunity to a third station, which is an associated station of the first AP or a station of another cell.

[0025] An allocation time in the first frame indicates that the first AP shares the transmission opportunity to the third station.

[0026] The first frame is a multi-user request to send (MU-RTS) transmission opportunity sharing (TXS) trigger (TF) frame.

[0027] Step 2: The first AP and the second station do not allow the use of the NPCA, or allow the use of the NPCA, or perform whether to allow the use of the NPCA according to the indication in the first information in an allocation time period from the end time of the first frame.

[0028] The first information is indicated by the first AP in a first management frame; the first management frame is a beacon frame or a probe response frame; and the first information indicates whether all stations in a cell where the first AP is located allow the use of the NPCA in an allocation time period, wherein a value 1 represents allowing, and a value 0 represents not allowing; or a value 0 represents allowing, and a value 1 represents not allowing.

[0029] In a third aspect, the present application provides a non-primary channel access method in a wireless local area network, and the specific steps are as follows:

[0030] Step 1: The first AP sends a first frame.

[0031] The first frame is used to indicate that the first AP shares its transmission opportunity to a third station, which is an associated station of the first AP or a station of another cell.

[0032] An allocation time in the first frame indicates that the first AP shares the transmission opportunity to the third station.

[0033] The first frame carries second information, which is used to indicate whether the first AP and the second station are allowed to use the NPCA in an allocation time period of the current transmission opportunity sharing; when a value 1 represents allowing, and a value 0 represents not allowing; or a value 0 represents allowing, and a value 1 represents not allowing; and the second station is an associated station of the first AP.

[0034] Optionally, the first frame carries third information, the third information being used to indicate whether the third station is allowed to send a transmission opportunity return frame; when the value 1 represents allowed, the value 0 represents not allowed, or the value 0 represents allowed, and the value 1 represents not allowed.

[0035] The first frame is a multi-user request to send (multi-user RTS, MU-RTS) transmission opportunity sharing (TXS) trigger (TF) frame.

[0036] The second information uses a reserved bit in a common information field (Common Info) in the MU-RTS frame, and the third information uses a reserved bit in the common information field (Common Info) in the MU-RTS frame; the second information and the third information are combined into a field carrying the second information, that is, one field indicates the second information and the third information at the same time; when the second information takes a value representing that the NPCA is not allowed, it also simultaneously represents that the third station is allowed to send the transmission opportunity sharing return frame in the third information. When the second information takes a value representing that the NPCA is allowed, it also simultaneously represents that the third station is not allowed to send the transmission opportunity sharing return frame in the third information.

[0037] Step 2: The second station receives the first frame sent by the first AP, and parses the transmission opportunity sharing allocation time (Allocation Time) and the second information from the first frame.

[0038] The first AP is an associated AP of the second station.

[0039] If the second information indicates that the NPCA is allowed to be used, the first AP and the second station allow the NPCA to be used in the allocation time (Allocation Time) period from the end time of the first frame.

[0040] If the second information indicates that the NPCA is not allowed to be used, the first AP and the second station do not allow the NPCA to be used in the allocation time (Allocation Time) period from the end time of the first frame.

[0041] Step 3: The third station receives the first frame sent by the first AP, and parses the transmission opportunity sharing allocation time (Allocation Time) from the first frame.

[0042] If the third information indicates that the third station is allowed to send the transmission opportunity sharing return frame, the third station sends the transmission opportunity sharing return frame in the allocation time (Allocation Time) period from the end time of the first frame.

[0043] If the third information indicates that the third station is not allowed to send the transmission opportunity sharing return frame, the third station is not allowed to send the transmission opportunity sharing return frame in an allocation time period from the end time of the first frame.

[0044] A communication device comprising means or modules for performing the method as described above.

[0045] A computer readable storage medium having stored therein program instructions which, when executed on a computer, cause the computer to perform the method as described above.

[0046] The present application has the beneficial effect of improving the consistency of AP and STA switching to work on the slave channel when performing NPCA, i.e. avoiding AP remaining to work on the master channel while STA switching to work on the slave channel. Thus, the number of retransmissions is reduced, the transmission packet loss rate is lowered, and the service quality is improved. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is the network structure of the WLAN of the present application.

[0048] Figure 2 is a schematic diagram of the WLAN multi-channel mechanism and the existing problems, Figure 2 (a) of is a diagram of node using multi-channel transmission, Figure 2 (b) of is a diagram of node using multi-channel transmission.

[0049] Figure 3 is a diagram of the technical principle of NPCA.

[0050] Figure 4 is a problem existing in the prior art.

[0051] Figure 5 is a problem existing in the prior art.

[0052] Figure 6 is a system architecture or scenario.

[0053] Figure 7 is a schematic diagram of embodiment 1.

[0054] Figure 8 (a) of is not allowed to use NPCA in the allocation time period of the transmission opportunity sharing; Figure 8 (b) of is allowed to use NPCA in the allocation time period of the transmission opportunity sharing; Figure 8 (c) of is that the AP indicates the first information in the first management frame. DETAILED DESCRIPTION

[0055] The application will be further described in connection with the accompanying drawings and examples.

[0056] The prior art related to the application is the non-primary channel access (NPCA) technology, such as Figure 3 The technical principle of NPCA is discussed as shown.

[0057] Step 1: When the AP and non-AP STA receive a PPDU from an external cell on the primary channel (PCH), and the duration of the NAV carried in the PPDU of the external cell is greater than a preset duration threshold, the AP and non-AP STA will immediately switch their radio frequency from the primary channel to a predetermined secondary channel (SCH) after the update of the basic NAV, and enter step 2;

[0058] Step 2: The AP and non-AP STA complete the radio frequency switching within a switching delay, and after the switching is completed, they receive and send on the secondary channel, and enter step 3;

[0059] Step 3: The AP and non-AP STA perform channel access and frame interaction on the secondary channel, and enter step 4.

[0060] Step 4: After the AP and non-AP STA complete the frame interaction on the secondary channel, they switch their radio frequency back to the primary channel, and need to ensure that the switching back to the primary channel is completed before the end time of the NAV carried in the PPDU of the external cell in step 1, and enter step 5.

[0061] Step 5: The AP and non-AP STA start to resume working on the primary channel.

[0062] Problem one of the prior art:

[0063] As Figure 4As shown, the non-AP STA of cell 1 sends a Request To Send (RTS) frame to the AP of cell 1, but since the non-AP STA 1 of cell 1 and the non-AP STA 2 of cell 1 are far away from each other, the RTS frame cannot be correctly received by the non-AP STA 2 of cell 1. The AP of cell 1 replies a Clear To Send (CTS) frame to the non-AP STA 1 of cell 1, at this time, the non-AP STA 2 of cell 1 correctly parses the CTS frame and obtains the NAV information in the CTS frame. Thus, the non-AP STA 2 of cell 1 updates its intra-BSS NAV according to the NAV information carried in the received CTS frame.

[0064] Next, the non-AP STA 1 of cell 1 sends a PPDU to the AP of cell 1, and since the non-AP STA 1 of cell 1 and the non-AP STA 2 of cell 1 are far away from each other, the PPDU sent by the non-AP STA 1 of cell 1 cannot be received by the non-AP STA 2 of cell 1. In this process, the station of cell 2 sends a PPDU, and the non-AP STA 2 of cell 1 receives the PPDU sent by the station of cell 2. Thus, the non-AP STA 2 of cell 1 identifies the PPDU as an inter-BSS PPDU, and according to the NPCA principle, the non-AP STA 2 of cell 1 switches to the slave channel to work. However, since the AP of cell 1 is currently receiving the PPDU of the non-AP STA 1 of cell 1, the AP will not switch to the slave channel to work. This causes the non-AP STA 2 of cell 1 repeatedly sends packets to the AP of cell 1 on the slave channel, but cannot get a response from the AP of cell 1, resulting in packet loss (corresponding to problem 1 in the background). Figure 4

[0065] In addition, as shown in FIG. 3, after the NAV duration of the non-AP STA 1 of cell 1 ends, the AP of cell 1 sends a frame to the non-AP STA 2 of cell 1, but since the non-AP STA 2 of cell 1 is still working on the slave channel and has not switched back to the master channel, the AP cannot get a response from the non-AP STA 2 of cell 1, resulting in packet loss (corresponding to problem 2 in the background). Figure 4 Figure 4

[0066] In fact, as long as the intra-BSS NAV of the station is not 0, and at this time a PPDU of an inter-BSS is received to cause switching to the slave channel, similar problems will occur. ​​​

[0067] Problem two of the prior art

[0068] As Figure 5 shown, the prior art allows an AP to share the transmission opportunity (TXOP) it has obtained with other stations, including in-cell stations and out-of-cell stations. The AP sends a "Transmission Opportunity Sharing Multi-User Send Request frame" (TXS MU-RTS frame), which contains the identification information of the stations to be allocated and the allocation duration information, which means that the transmission opportunity is given to the sharing transmission opportunity stations in the future allocation time. For example, Figure 5 The AP in the in-cell sends a "Transmission Opportunity Sharing Multi-User Send Request frame" (TXS MU-RTS frame) to share the transmission opportunity with the sharing transmission opportunity stations. If the sharing transmission opportunity stations are out-of-cell stations, or the sharing transmission opportunity stations perform P2P transmission, the PPDU sent by the sharing transmission opportunity stations is identified as an out-of-cell PPDU by the non-AP STAs S2 in the in-cell 1, so that according to the NPCA principle, the non-AP STAs S2 in the in-cell 1 switch to the slave channel. However, the AP in the in-cell still works on the master channel, because the sharing transmission opportunity stations may return the transmission opportunity in advance. This causes the non-AP STAs S2 in the in-cell 1 to repeatedly send packets to the AP in the in-cell 1 on the slave channel, and none of them can get a response from the AP in the in-cell 1, causing the problem of packet loss (corresponding to Figure 5 Problem 1).

[0069] If the sharing transmission opportunity stations send a transmission opportunity return frame to the AP in the in-cell 1 in advance, the AP in the in-cell 1 will continue to have the transmission opportunity. The AP in the in-cell 1 sends a frame to the non-AP STAs S2 in the in-cell 1, but since the non-AP STAs S2 in the in-cell 1 are still working on the slave channel and have not switched back to the master channel, the AP cannot send a frame to the non-AP STAs S2 in the in-cell 1, causing the problem of packet loss (corresponding to Figure 5 Problem 2).

[0070] The present solution relates to data communication between an AP and one or more STAs, and is also applicable to communication between APs, and communication between STAs. As Figure 6 shown.

[0071] In the first embodiment, when the intra-BSS NAV of a station is not 0, NPCA switching to the slave channel is not allowed.

[0072] The steps of the first embodiment are:

[0073] Step 1: When the first station receives the first PPDU, if the first PPDU is like coming from an external cell, go to Step 2, if the first PPDU is not coming from an external cell, end the flow;

[0074] Step 2: The first station checks if the current own intra-BSS NAV is 0, if the intra-BSS NAV is not 0, go to Step 3, if the intra-BSS NAV is 0, go to Step 4;

[0075] Step 3: The first station is not allowed to perform NPCA according to the received first PPDU, i.e. the first station is not allowed to switch to work from the channel after receiving the first PPDU, end the flow;

[0076] Step 4: If the first station satisfies the first condition, the first station is allowed to perform NPCA according to the received first PPDU, if the first station does not satisfy the first condition, the first station is not allowed to perform NPCA according to the received first PPDU.

[0077] The first condition is that the time length of the NAV carried in the first PPDU is greater than or equal to a first threshold, end the flow. The first threshold is a preset time length, and the value of the first threshold is 2 milliseconds (ms) in the present application.

[0078] The effect of Embodiment 1 is introduced by taking Figure 7 as an example.

[0079] The non-AP STA of cell 1 sends a request to send frame (RTS) to the AP, the AP of cell 1 sends a clear to send frame (CTS) to the non-AP STA 1 of cell 1, at this time, the non-AP STA 2 of cell 1 can correctly parse the CTS frame, thereby obtaining the NAV information in the CTS frame. Therefore, the non-AP STA 2 of cell 1 updates the intra-BSS NAV according to the NAV information carried in the received CTS frame.

[0080] Next, the station of cell 2 sends a PPDU, and the non-AP STA 2 of cell 1 receives the PPDU sent by the station of cell 2. Thus, and the non-AP STA 2 of cell 1 identifies the PPDU as an out-cell PPDU, but according to the principle of embodiment 1, since the non-AP STA 2 checks that its intra-BSS NAV is not equal to 0, thus does not perform NPCA, i.e. does not switch to work on the secondary channel.

[0081] After the NAV duration of the non-AP STA 1 of cell 1 ends, the AP of cell 1 sends a frame to the non-AP STA 2 of cell 1, and since the non-AP STA 2 of cell 1 is still working on the primary channel, the AP sending the frame to the non-AP STA 2 of cell 1 is responded.

[0082] Effect of embodiment 1: the problem of prior art is solved.

[0083] Embodiment 2 is whether to allow using NPCA in the time period of transmission opportunity sharing.

[0084] In the present application, allowing using NPCA is equivalent to enabling NPCA, i.e. allowing the station to switch to work on the secondary channel according to the principle of NPCA. In the present application, not allowing using NPCA is equivalent to prohibiting NPCA, i.e. not enabling NPCA, i.e. not allowing the station to switch to work on the secondary channel according to the principle of NPCA. As Figure 8 shown.

[0085] Embodiment 2 is as follows:

[0086] Step 1: the second station receives a first frame sent by a first AP, and parses the allocation time of transmission opportunity sharing from the first frame;

[0087] The first AP is an associated AP of the second station;

[0088] The first frame is used to indicate that the first AP shares the transmission opportunity of the first AP to a third station, and the third station is an associated station of the first AP or a station of another cell.

[0089] The first frame indicates the allocation time of transmission opportunity shared by the first AP to the third station.

[0090] The first frame is a multi-user request to send frame (MU-RTS) transmission opportunity sharing (TXS) trigger (TF) frame.

[0091] Step 2: The first AP and the second station are not allowed to use NPCA (as shown in a of Figure 8 ), or are allowed to use NPCA (as shown in b of Figure 8 ), or perform whether to allow to use NPCA according to the indication in the first information.

[0092] The first information is indicated by the first AP in the first management frame (as shown in c of Figure 8 ). The first management frame is a beacon frame (Beacon) or a probe response frame (Probe Response); the first information indicates whether all stations in the cell (i.e. BSS) where the first AP is located are allowed to use NPCA in the allocation time period, and the value 1 represents allowed, and the value 0 represents not allowed; or the value 0 represents allowed, and the value 1 represents not allowed.

[0093] The effect of embodiment two is that the second problem of the prior art is solved.

[0094] Embodiment three is to indicate in the first frame whether to allow NPCA in the time period of transmission opportunity sharing.

[0095] The steps of embodiment three are as follows:

[0096] Step 1: The first AP sends a first frame.

[0097] The first frame is used to indicate that the first AP shares its transmission opportunity to a third station, which is an associated station of the first AP or a station of other cells.

[0098] The first frame indicates the allocation time (Allocation Time) of the transmission opportunity shared by the first AP to the third station.

[0099] The first frame carries second information, which is used to indicate whether the first AP and the second station are allowed to use NPCA in the allocation time period of the transmission opportunity sharing this time; for example, the value 1 represents allowed, and the value 0 represents not allowed. Or the value 0 represents allowed, and the value 1 represents not allowed. The second station is an associated station of the first AP.

[0100] Optionally, the first frame carries third information, which is used to indicate whether the third station is allowed to send a transmission opportunity return frame. For example, the value 1 represents allowed, and the value 0 represents not allowed, or the value 0 represents allowed, and the value 1 represents not allowed.

[0101] The first frame is a Multi-User Request to Send (MU-RTS) Transmission Opportunity Sharing (TXS) Triggered (TF) frame.

[0102] The second information uses reserved bits in the Common Info field of the MU-RTS frame, and the third information also uses reserved bits in the Common Info field of the MU-RTS frame. The second and third information are combined into a single field carrying the second information; that is, one field simultaneously indicates both the second and third information. For example, when the second information value indicates that NPCA is not allowed, it also simultaneously indicates that the third information allows the third station to send a Transmission Opportunity Sharing Return frame. Conversely, when the second information value indicates that NPCA is allowed, it also simultaneously indicates that the third information does not allow the third station to send a Transmission Opportunity Sharing Return frame.

[0103] Step 2: The second station receives the first frame sent by the first AP and parses the allocation time and second information of the transmission opportunity sharing from the first frame;

[0104] The first AP is the associated AP of the second site;

[0105] If the second information indicates that NPCA is permitted, then the first AP and the second site are permitted to use NPCA for the allocation time period starting from the end of the first frame.

[0106] If the second information indicates that NPCA is not allowed, then the first AP and the second site are not allowed to use NPCA during the allocation time period starting from the end of the first frame.

[0107] Step 3: (Optional) The third station receives the first frame sent by the first AP and parses the allocation time for the transmission opportunity sharing from the first frame.

[0108] If the third information indicates that the third station is permitted to send a transmission opportunity sharing return frame, then the third station may send a transmission opportunity sharing return frame during the allocation time period starting from the end of the first frame.

[0109] If the third information indicates that the third station is not allowed to send a Transmission Opportunity Share Return Frame, then the third station is not allowed to send a Transmission Opportunity Share Return Frame during the Allocation Time period starting from the end of the first frame.

[0110] Effect of Example 3: The problems of the prior art are solved. And it is more flexible than Example 3.

Claims

1. A method for accessing a non-primary channel in a wireless local area network, characterized in that... Includes the following steps: Step 1: The first AP sends the first frame; The first frame is used to instruct the first AP to share its transmission opportunities with a third site, which is either an associated site of the first AP or a site of another cell. The first frame indicates the allocation duration for which the first AP will share transmission opportunities with the third site; The first frame carries second information, which is used to indicate whether the first AP and the second site are allowed to use NPCA during the allocated time period of this transmission opportunity sharing; A value of 1 represents permission, and a value of 0 represents disallowment; or a value of 0 represents permission, and a value of 1 represents disallowment. The second site is an associated site of the first AP; The first frame is a multi-user request to send frame transmission opportunity sharing trigger frame; The second information uses the reserved bits in the common information field of the MU-RTS frame, and the third information uses the reserved bits in the common information field of the MU-RTS frame; the second and third information are merged into one field carrying the second information, that is, one field simultaneously indicates the second and third information; when the value of the second information indicates that NPCA is not allowed, it also indicates that the third station is allowed to send a transmission opportunity sharing return frame in the third information; when the value of the second information indicates that NPCA is allowed, it also indicates that the third station is not allowed to send a transmission opportunity sharing return frame in the third information. Step 2: The second station receives the first frame sent by the first AP and parses the second information of the allocation duration of the transmission opportunity sharing from the first frame; The first AP is the associated AP of the second site; If the second information indicates that NPCA is permitted, then the first AP and the second site are permitted to use NPCA for the allocated time period starting from the end of the first frame; If the second information indicates that NPCA is not allowed, then the first AP and the second station are not allowed to use NPCA during the allocated time period starting from the end of the first frame. Step 3: The third station receives the first frame sent by the first AP and parses the allocated duration of the transmission opportunity sharing from the first frame.

2. The method for accessing a non-main channel in a wireless local area network according to claim 1, characterized in that: In step 1, the first frame carries third information, which is used to indicate whether the third station is allowed to send a transmission opportunity return frame. A value of 1 indicates permission, and a value of 0 indicates disallowment, or a value of 0 indicates permission, and a value of 1 indicates disallowment.

3. The method for accessing a non-main channel in a wireless local area network according to claim 1, characterized in that: In step 3, if the third information indicates that the third station is allowed to send a transmission opportunity sharing return frame, then the third station sends a transmission opportunity sharing return frame during the allocated time period starting from the end of the first frame. If the third information indicates that the third station is not allowed to send a Transmission Opportunity Share Return Frame, then the third station is not allowed to send a Transmission Opportunity Share Return Frame during the allocated time period starting from the end of the first frame.

4. A communication device comprising a unit or module for performing the method as described in any one of claims 1-3.

5. A computer-readable storage medium storing program instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1-3.

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