Channel access method and apparatus

Abstract

The present application provides a channel access method and device, which is conducive to shortening the time for a device to access a channel and improving the efficiency of channel competition. The method includes: a first device executes a backoff process; when the value of the backoff counter is zero, a first frame is sent to a second device, the protocol data unit PPDU format of the first frame is a set format, the frame control field, transmission duration field, address field and scrambling code seed included in the first frame are all set values, and the first frame is used to transfer the channel scheduling right to the second device.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communications, and in particular to a channel access method and device. Background Art

[0002] In a wireless local area network (WLAN), a station (STA) that has data to send competes for a channel through a carrier sense multiple access (CSMA) / collision avoidance (CA) mechanism to obtain the right to send data.

[0003] In order to improve the efficiency of channel use, an existing design is to make any station in the basic service set (BSS) that successfully competes for the channel hand over the channel scheduling right to the access point (AP) through a frame (for example, a request to send (RTS)) frame, and the AP is responsible for scheduling the use of the channel. However, for multiple stations that perform the backoff process based on the CSMA / CA mechanism, when the backoff counters of multiple stations are zero at the same time, the RTS frames sent by multiple stations at the same time will fail to be sent due to collision, and the backoff counter values ​​of the colliding stations may still be the same, which will continue to cause collisions and generate longer delays. Summary of the invention

[0004] The present application provides a channel access method and apparatus, which are beneficial to shortening the time for a device to access a channel and improving channel competition efficiency.

[0005] In a first aspect, a channel access method is provided, including: a first device executes a backoff process; when the value of a backoff counter is zero, a first frame is sent to a second device, the protocol data unit PPDU format of the first frame is a set format, and the frame control field, transmission duration field, address field and scrambling code seed included in the first frame are all set values, and the first frame is used to transfer the channel scheduling right to the second device.

[0006] In an embodiment of the present application, when the first device determines that the value of the backoff counter is zero, it sends a first frame to the second device, in which the PPDU format is a set format, and the frame type field, the transmission duration field, the address field, and the scrambling code seed are all set values. Since all information contained in the first frame is pre-set and will not change with the different devices sending the first frame, when there are multiple devices sending the first frame to the second device at the same time, for the second device, receiving multiple first frames is equivalent to receiving a multipath signal of the first frame sent by the same device. After receiving the first frame, the second device becomes a transmission opportunity (TXOP) holder and has the right to schedule the channel. It can send data to other devices, or schedule other devices to send uplink data by triggering frames. According to the method provided in the embodiment of the present application, when the first device successfully competes for the channel (i.e., the backoff counter value returns to zero), the first device transfers the channel scheduling right to the second device through a first frame with a fixed format and content. Since the first frame does not change with different sending devices, when there are multiple devices that successfully compete to send the first frame at the same time, the second device can still normally receive multiple first frames sent by multiple devices, thereby avoiding the delay caused by each device reselecting the contention window for backing off after the collision of the first frame, which is beneficial to shortening the time for the second device to access the channel and improving the efficiency of channel competition.

[0007] It should be understood that the first device and the second device belong to the same BSS. After receiving the first frame, the second device has the scheduling right of the channel for which the first device has competed. The second device can send data or trigger frames to any device in the BSS. The device that receives the data or trigger frame can be the first device or other devices in the BSS. This application does not limit this.

[0008] It should also be understood that the PPDU format included in the first frame described in the embodiment of the present application is a set format, and the frame control field, transmission duration field, address field and scrambling code seed are all set values, which means that the format and content of the first frame are pre-set, and the PPDU format, frame control field, transmission duration field, address field and scrambling code seed in the first frame sent by any two devices are the same.

[0009] In combination with the first aspect, in some implementations of the first aspect, the address field includes a receiving address field and a sending address field, the receiving address field is a MAC address of the second device, and the sending address field is a set MAC address.

[0010] In the existing standards, for a frame that requires a response, the receiving address field is the MAC address of the device that receives the frame, and the sending address field is the MAC address of the device that sends the frame. In the first frame provided by the present application, the receiving address field is the MAC address of the second device, and the sending address field is set to a set MAC address. The second device can identify this frame as the first frame to transfer channel scheduling rights based on the difference between the setting of the sending address and the prior art.

[0011] Optionally, the MAC address set in the sending address field can be any broadcast address, multicast address, or address of other devices that do not interact with the second device, and this application does not make specific limitations on this.

[0012] In combination with the first aspect, in certain implementations of the first aspect, at least one of the following fields in the frame control field is set to 1: To DS field, From DS field, MoreFragments field, Retry field, Power Management field, More Data field, and Protected Frame field.

[0013] It should be understood that the To DS field, From DS field, More Fragments field, Retry field, Power Management field, More Data field, and Protected Frame field in the control frame in the existing standard are all set to zero. In the case where the frame type of the first frame provided in the present application is a control frame, one or more designated fields of these fields set to zero in the prior art are set to 1 to distinguish the first frame from other existing control frames. The "designated" here refers to the agreement by the protocol. For example, the protocol stipulates that the first frame is a control frame and only the More Fragments field of the above fields included in the frame control field of the first frame is set to 1. Then, no matter which device sends the first frame, the difference between it and the existing control frame is that the value of the More Fragments field is 1.

[0014] In the embodiment of the present application, the first frame is identified by using the reserved field in the frame control field that is not given actual meaning in the control frame in the prior art, and the second device can identify the first frame based on this mark. The method provided by the present application can implicitly identify the first frame without occupying the type field or subtype field of the frame, which reserves more possibilities for the definition of the frame type.

[0015] In combination with the first aspect, in certain implementations of the first aspect, the first device belongs to a first group, the PPDU format of the first frame sent by different devices in the first group is the same, and the following fields included in the first frame sent by different devices in the first group have the same values: frame control field, transmission duration field, address field and scrambling code seed.

[0016] Optionally, the first group may include all devices in the BSS where the first device is located, or may only include some devices in the BSS where the first device is located, which is not limited in the present application.

[0017] Optionally, the first group may be devices having the same service and / or the same service period, which is not limited in the present application.

[0018] In the embodiment of the present application, the device with data to send in the first group can participate in the competition, or it can be agreed that the device can participate in the competition regardless of whether it has data to send, and the channel scheduling right is handed over to the second device after the channel competition is successful, so as to improve the success rate of the first group channel competition. When the backoff counters of multiple devices in the first group back off to zero at the same time, the multiple devices simultaneously send the first frame to the second device, and the PPDU format of the first frame sent by the multiple devices is the same format, and the frame control field, transmission duration field, address field and scrambling code seed are all the same value. Therefore, the second device is equivalent to receiving the multipath signal of the first frame, and no collision will occur. Devices whose backoff counters back off to zero at the same time do not need to reselect the backoff time to continue to compete, which is conducive to avoiding delays caused by collisions. The second device can obtain the channel scheduling right in time, thereby improving the efficiency of channel competition.

[0019] In combination with the first aspect, in some implementations of the first aspect, the method further includes: the first device receiving first configuration information from the second device, the first configuration information being used to indicate that the first device belongs to the first group.

[0020] In combination with the first aspect, in some implementations of the first aspect, the method also includes: the first device receives group indication information from the second device, the group indication information includes a group identifier of at least one group; the first device sends a first request to the second device based on the group indication information, and the first request is used to request to join a first group in the at least one group; the first device receives a first response from the second device to the first request.

[0021] It should be understood that when the above-mentioned first response is a response to the success of the first request, it means that the second device agrees that the first device joins the first group.

[0022] In combination with the first aspect, in certain implementations of the first aspect, the first group is grouped through a broadcast target wake-up time B-TWT mechanism or a restricted target wake-up time R-TWT mechanism.

[0023] In combination with the first aspect, in some implementations of the first aspect, the method also includes: the first device receives second configuration information, and the second configuration information is used to configure the first service period; the first device executes the backoff process, including: the first device executes the backoff process within the first service period.

[0024] It should be understood that the first service period is a period during which the first device is allowed to compete for the channel. When the first service period arrives, the first device can participate in the channel competition to assist the second device in obtaining the channel scheduling right as soon as possible.

[0025] In combination with the first aspect, in some implementations of the first aspect, the first device is an access point AP or a non-access point station non-AP STA.

[0026] In combination with the first aspect, in some implementations of the first aspect, the first frame is a request to send RTS frame or a permission to send CTS frame.

[0027] The first frame provided in the embodiment of the present application has a type field value that corresponds to RTS or CTS, but the reserved field, address field and transmission duration field in its frame control field are partially or completely different from those in the prior art, in order to allow the second device to recognize the first frame.

[0028] In combination with the first aspect, in certain implementations of the first aspect, the PPDU format is a non-HT PPDU or a non-HT duplicate PPDU.

[0029] It should be understood that the first frame includes a physical layer (PHY) structure and a MAC layer structure. The PPDU format provided in the embodiment of the present application is a limitation on the format of the physical layer of the first frame. The PPDU format is the encapsulation format of the frame generated by the physical layer to the MAC layer.

[0030] In the second aspect, the present application also provides a channel access method, including: a second device receives a first frame, the protocol data unit PPDU format of the first frame is a set format, the frame control field, transmission duration field, address field and scrambling code seed included in the first frame are all set values, and the first frame is used to transfer the channel scheduling right to the second device; the second device sends data or a trigger frame, and the trigger frame is used to schedule uplink data.

[0031] In combination with the second aspect, in certain implementations of the second aspect, the method also includes: the second device receives a second frame sent by a third device, and the PPDU format, frame control field, transmission duration field, address field and scrambling code seed of the second frame are the same as those of the first frame.

[0032] In combination with the second aspect, in some implementations of the second aspect, the address field includes a receiving address field and a sending address field, the receiving address field is a media access control MAC address of the second device, and the sending address field is a set MAC address.

[0033] In combination with the second aspect, in certain implementations of the second aspect, at least one of the following fields in the frame control field is set to 1: To DS field to the distributed system, From DS field from the distributed system, More Fragments field, Retry field, Power Management field, More Data field, and Protected Frame field.

[0034] In combination with the second aspect, in some implementations of the second aspect, the method further includes: the second device sends first configuration information to the first device, where the first configuration information is used to indicate that the first device belongs to a first group.

[0035] In combination with the second aspect, in some implementations of the second aspect, the method also includes: the second device sends group indication information, the group indication information includes a group identifier of at least one group; the second device receives a first request from the first device, the first request is used to request to join a first group in the at least one group; the second device sends a first response to the first request to the first device.

[0036] In combination with the second aspect, in certain implementations of the second aspect, the first group is grouped through a broadcast target wake-up time B-TWT mechanism or a restricted target wake-up time R-TWT mechanism.

[0037] In combination with the second aspect, in certain implementations of the second aspect, the first device belongs to a first group, the PPDU format of the first frame sent by different devices in the first group is the same, and the following fields included in the first frame sent by different devices in the first group have the same values: frame control field, transmission duration field, address field and scrambling code seed.

[0038] In combination with the second aspect, in some implementations of the second aspect, the method also includes: the second device sends second configuration information to the first device, the second configuration information is used to configure the first service period; the first device performs a backoff process within the first service period.

[0039] In combination with the second aspect, in some implementations of the second aspect, the second device is an access point AP or a non-access point station non-AP STA.

[0040] In combination with the second aspect, in some implementations of the second aspect, the first frame is a request to send RTS frame or a permission to send CTS frame.

[0041] In combination with the second aspect, in certain implementations of the second aspect, the PPDU format is a non-HT PPDU or a non-HT duplicate PPDU.

[0042] In the third aspect, the present application also provides a channel access method, which is applied to a first group including a first device, a second device and a third device, and the method includes: the first device executes a backoff process; when the value of the backoff counter is zero, the first device sends a first frame to the second device, and the protocol data unit PPDU format of the first frame is a set format, and the frame control field, transmission duration field, address field and scrambling code seed included in the first frame are all set values, and the first frame is used to transfer the channel scheduling right to the second device; the third device executes the backoff process; when the value of the backoff counter is zero, the third device sends a second frame to the second device, and the PPDU format, frame control field, transmission duration field, address field and scrambling code seed in the second frame are the same as those of the first frame; the second device receives the first frame and the second frame; the second device sends data or a trigger frame, and the trigger frame is used to schedule uplink data.

[0043] According to the method provided by the embodiment of the present application, the frames sent by the first device and the third device for transferring the channel scheduling right when the backoff counter backs off to zero are exactly the same frames. When the backoff counters of the first device and the second device back off to zero at the same time, the first frame sent by the first device will not collide with the second frame sent by the third device. For the first device and the third device, the channel scheduling right can be transferred to the second device without further backing off. For the second device, it can access the channel in a timely manner, thereby improving the efficiency of channel access.

[0044] In combination with the third aspect, in certain implementations of the third aspect, the first frame is a frame that requires a response, the address field includes a receiving address field and a sending address field, the receiving address field is a media access control MAC address of the second device, and the sending address field is a set MAC address.

[0045] In combination with the third aspect, in certain implementations of the third aspect, at least one of the following fields in the frame control field is set to 1: To DS field to the distributed system, From DS field from the distributed system, More Fragments field, Retry field, Power Management field, More Data field, and Protected Frame field.

[0046] In combination with the third aspect, in some implementations of the third aspect, the method further includes: the second device sends first configuration information to the first device, where the first configuration information is used to indicate that the first device belongs to a first group.

[0047] In combination with the third aspect, in some implementations of the third aspect, the method also includes: the second device sends group indication information, the group indication information includes a group identifier of at least one group; the second device receives a first request from the first device, the first request is used to request to join a first group in the at least one group; the second device sends a first response to the first request to the first device.

[0048] In combination with the third aspect, in certain implementations of the third aspect, the first group is grouped through a broadcast target wake-up time B-TWT mechanism or a restricted target wake-up time R-TWT mechanism.

[0049] In combination with the third aspect, in certain implementations of the third aspect, the method also includes: the second device sends second configuration information to the first device, and the second configuration information is used to configure the first service period; the first device executes the backoff process, including: the first device executes the backoff process within the first service period.

[0050] In combination with the third aspect, in some implementations of the third aspect, the first device and the third device are non-access point stations (non-AP STAs).

[0051] In combination with the third aspect, in some implementations of the third aspect, the second device is an access point AP.

[0052] In combination with the third aspect, in certain implementations of the third aspect, the first frame is a request to send an RTS frame or a permission to send a CTS frame.

[0053] In combination with the third aspect, in certain implementations of the third aspect, the PPDU format is a non-HT PPDU or a non-HT duplicate PPDU.

[0054] In a fourth aspect, the present application also provides a channel access method, comprising: a first device executes a backoff process; when the value of a backoff counter is zero, a first frame is sent to a second device, wherein the first device belongs to a first group, and first frames sent by different devices in the first group are the same.

[0055] In a fifth aspect, a channel access device is provided, which includes a module for executing a method in any possible implementation of the first aspect, the second aspect or the fourth aspect.

[0056] In a sixth aspect, a communication system is provided, comprising a first device, a second device and a third device, for executing a method in any possible implementation manner of the third aspect.

[0057] In a seventh aspect, the present application provides another channel access device, including a processor, the processor is coupled to a memory, and can be used to execute instructions in the memory to implement the method in any possible implementation of the first aspect, the second aspect, or the fourth aspect. Optionally, the device also includes a memory. Optionally, the device also includes a communication interface, and the processor is coupled to the communication interface.

[0058] In one implementation, the apparatus is a terminal device. When the apparatus is a terminal device, the communication interface may be a transceiver, or an input / output interface.

[0059] In another implementation, the device is a chip configured in a terminal device. When the device is a chip configured in a terminal device, the communication interface may be an input / output interface.

[0060] In an eighth aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is used to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor executes the method in any possible implementation of the first aspect, the second aspect, or the fourth aspect.

[0061] In the specific implementation process, the processor may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a trigger, and various logic circuits. The input signal received by the input circuit may be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit may be, for example, but not limited to, output to a transmitter and transmitted by the transmitter, and the input circuit and the output circuit may be the same circuit, which is used as an input circuit and an output circuit at different times. The embodiments of the present application do not limit the specific implementation methods of the processor and various circuits.

[0062] In a ninth aspect, a processing device is provided, comprising a processor and a memory. The processor is used to read instructions stored in the memory, and can receive signals through a receiver and transmit signals through a transmitter to execute the method in any possible implementation of the first aspect, the second aspect, or the fourth aspect.

[0063] Optionally, the number of the processors is one or more, and the number of the memories is one or more.

[0064] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0065] In the specific implementation process, the memory can be a non-transitory memory, such as a read-only memory (ROM), which can be integrated with the processor on the same chip or can be set on different chips respectively. This application does not limit the type of memory and the setting method of the memory and the processor.

[0066] It should be understood that the relevant data interaction process, such as sending indication information, can be a process of outputting indication information from a processor, and receiving capability information can be a process of receiving input capability information from a processor. Specifically, the processed output data can be output to a transmitter, and the input data received by the processor can come from a receiver. Among them, the transmitter and the receiver can be collectively referred to as a transceiver.

[0067] The processing device in the above-mentioned ninth aspect can be a chip. The processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading the software code stored in the memory. The memory can be integrated in the processor or can be located outside the processor and exist independently.

[0068] In the tenth aspect, a computer program product is provided, which includes: a computer program (also referred to as code, or instruction), which, when executed, enables a computer to execute a method in any possible implementation of the first aspect, the second aspect, or the fourth aspect.

[0069] In the eleventh aspect, a computer-readable storage medium is provided, which stores a computer program (also referred to as code, or instructions). When the computer-readable storage medium is run on a computer, the computer executes a method in any possible implementation of the first aspect, the second aspect, or the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 A schematic diagram of a communication system applicable to an embodiment of the present application;

[0071] Figure 2 This is a schematic diagram of an existing random backoff mechanism;

[0072] Figure 3 A schematic flow chart of a channel access method provided by the present application;

[0073] Figure 4 A schematic diagram of a control frame structure provided for this application:

[0074] Figure 5 A schematic diagram of the frame structure of another control frame provided for this application:

[0075] Figure 6 A schematic diagram of a frame control field structure provided for this application;

[0076] Figure 7 A schematic diagram of a grouping mechanism provided for this application;

[0077] Figure 8 A schematic diagram of the implementation process of a channel access method provided in this application;

[0078] Fig. 9 A schematic diagram of an implementation process of another channel access method provided in the present application;

[0079] Fig.10 A schematic block diagram of a channel access device provided in an embodiment of the present application;

[0080] Fig.11 A schematic block diagram of another channel access device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0081] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0082] In the embodiments of the present application, terms such as "first" and "second" are used to distinguish identical or similar items with basically the same functions and roles. For example, the first value and the second value are only used to distinguish different values, and do not limit their order. Those skilled in the art can understand that terms such as "first" and "second" do not limit the quantity and execution order, and the terms "first", "second", etc. do not necessarily mean different.

[0083] It should be noted that in the embodiments of the present application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplarily" or "for example" in this application should not be construed as being more preferred or having more advantages than other embodiments or designs. Rather, the use of words such as "exemplarily" or "for example" is intended to present related concepts in a specific manner.

[0084] In the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (s) or plural item (s). For example, at least one (item) of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple.

[0085] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: wireless local area network (WLAN) communication system, general packet radio service (GPRS), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or new radio (NR), etc.

[0086] The following is an exemplary description, taking the WLAN system as an example to describe the application scenario of the embodiment of the present application and the method of the embodiment of the present application.

[0087] Specifically, the embodiments of the present application can be applied to a wireless local area network (WLAN), and the embodiments of the present application can be applied to any one of the IEEE 802.11 series protocols currently adopted by the WLAN, and are particularly applicable to WLAN systems of the 802.11be standard, the 802.11bn standard, and subsequent improved standards of the standards. A WLAN may include one or more basic service sets (BSS), and network nodes in the basic service set may include access points (APs) and stations (STAs).

[0088] Specifically, the station (STA) in the embodiment of the present application may also be referred to as a system, a user unit, an access terminal, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, a user device or a user equipment (UE). The STA may be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with a wireless local area network (e.g., Wi-Fi) communication function, a wearable device, a computing device, or other processing devices connected to a wireless modem. Among them, STA products are generally terminal products that support the IEEE 802.11 series of standards, such as mobile phones, laptops, etc. STA may be a single antenna or a multi-antenna, and may be a device with more than two antennas. Exemplarily, STA may include a physical layer (PHY) processing circuit and a media access control (MAC) processing circuit, the physical layer processing circuit may be used to process physical layer signals, and the MAC layer processing circuit may be used to process MAC layer signals.

[0089] The access point (AP) in the embodiment of the present application can be used to communicate with the STA through the wireless local area network, and transmit the data of the STA to the network side, or transmit the data from the network side to the STA. AP can also be called a wireless access point or hotspot, etc. AP is an access point for mobile users to enter the wired network, which is mainly deployed in homes, buildings and parks, and can also be deployed outdoors. AP is equivalent to a bridge connecting the wired network and the wireless network. Its main function is to connect various wireless network clients together and then connect the wireless network to the Ethernet. Specifically, AP can be a terminal device or network device with a wireless fidelity (wireless fidelity, Wi-Fi) chip. Optionally, AP can be a device that supports multiple WLAN formats such as 802.11. Specifically, AP can be multi-antenna or single-antenna. Exemplarily, AP may include a physical layer (physical layer, PHY) processing circuit and a media access control (media access control, MAC) processing circuit, the physical layer processing circuit can be used to process physical layer signals, and the MAC layer processing circuit can be used to process MAC layer signals.

[0090] Figure 1 FIG. 1 is a schematic diagram showing an application scenario according to an embodiment of the present application. Figure 1The scenario system shown may be a WLAN system, Figure 1 A WLAN system may include an AP and one or more STAs. Figure 1 Take an AP (AP 1) and three STAs (STA 1, STA 2, and STA 3) as an example, wherein AP and STA, and STA and STA can perform wireless communication through various standards.

[0091] Specifically, AP and STA can use single-user multiple-input multiple-output (SU-MIMO) technology or multi-user multiple-input multiple-output (MU-MIMO) technology for wireless communication. In an embodiment of the present application, each STA is equipped with one or more antennas. Each AP supports multi-site parallel uplink transmission. Specifically, STA or AP includes an antenna with an adjustable beam, a radio frequency channel (RF) corresponding to the antenna, a signal processing module, a protocol module, etc.

[0092] The connection between the antenna and the RF channel can be a specified connection or a switchable connection. The RF channel will be connected to the signal processing module to perform digital to analog or analog to digital conversion and perform transceiver signal processing. The signal processing module can generate reference signals for measurement and receive reference signals to estimate signal strength, channel quality, or channel coefficients. The signal processing module is also connected to a local clock source to modulate the signal to a target frequency band or demodulate it. The local clock source can also provide a time reference for when to send a specified physical layer protocol data unit (PHY) protocol data unit (PPDU). The signal processing module can trigger the sending of a specified PPDU at a specified time. The signal processing module is also connected to the protocol module to perform packet encapsulation and unpacking, and execute the packet transceiver sequence agreed upon by the protocol, including sending training frames, receiving training frames, replying response frames, etc. The signal processing module or the protocol module can also indicate the beam used by the antenna in sending or receiving.

[0093] Optionally, the STA or AP in the embodiment of the present application may further include an external interface module, but the embodiment of the present application is not limited thereto.

[0094] Below, some concepts or terms involved in this application are briefly introduced.

[0095] 1. Basic service set (BSS)

[0096] The basic service set is the basic component of the 802.11 local area network. A BSS includes an access point (AP) and several stations (STA). All STAs can communicate directly within the BSS, but when communicating with STAs outside the BSS, they need to go through the AP of the BSS.

[0097] 2. Network allocation vector (NAV)

[0098] Virtual carrier sense is a type of carrier sense that uses control information to learn about channel conditions rather than actually detecting physical channels. Virtual carrier sense uses the relevant information carried in the medium access control (MAC) frame to achieve logical predictions. That is, each frame carries the transmission duration information of the next frame of the transmitting device, and the related devices predict the channel occupancy based on this transmission duration information. If a device does not detect the transmission duration information, for example, when monitoring the carrier, the transmission duration field of this frame has been transmitted, the device can only rely on physical layer detection.

[0099] Virtual carrier sensing can be implemented using the network allocation vector NAV. NAV is essentially a countdown timer that decreases as time passes. When the countdown reaches 0, the medium is considered to be in an idle state. Therefore, virtual carrier sensing technology sets and updates the timing value of NAV with an appropriate value at the appropriate time. For example, when a device receives a frame, if the receiving address of the frame is not the device, the device can update NAV based on the transmission duration field in the received frame. If the receiving address of the frame is the device, it means that the device is a receiving device and NAV cannot be updated.

[0100] 3. Distributed coordination function (DCF)

[0101] DCF is a mandatory technology for preventing collisions in wireless LANs based on the IEEE 802.11 standard. It is a medium access control (MAC) sublayer technology used in areas that use carrier sense multiple access with collision avoidance (CSMA / CA).

[0102] According to the basic technical process of DCF, before sending data or management frames, device 1 needs to call the carrier sensing (CS) mechanism to determine whether the channel status is idle or busy. It should be understood that device 1 can be a STA or an AP.

[0103] When the channel is detected to be in a busy state, the device 1 postpones the channel access time for a specific time. There are two cases for this specific time. One case is that when the device 1 detects a frame but fails to receive it successfully, the specific time is the extended interframe space (EIFS), EIFS=aSIFSTime+AckTxTime+DIFS; the other case is that the specific time is the distributed coordination function Interframe Space (DIFS), DIFS=aSIFSTime+2*aSlotTime, EIFS=aSIFSTime+AckTxTime+DIFS, AckTxTime is the transmission duration of the acknowledgment (ACK) frame. Usually, the duration of a short interframe space (SIFS) (aSIFSTime) is 16 microseconds, and the duration of a slot (aSlotTime) is 9 microseconds. Depending on the spectrum and protocol, the specific values ​​of aSIFSTime and aSlotTime may also be different, and this application does not limit the specific values.

[0104] When it is detected that the channel is idle for DIFS or EIFS (DIFS is used as an example in the following description), the backoff counter value selected by device 1 is reduced by 1 every time the channel is idle for one time slot. When the backoff counter value is reduced to 0, data is sent.

[0105] Figure 2 A random backoff mechanism is shown. Figure 2 As shown, the transmitting device detects that the channel is busy and waits for the channel to be idle for a DIFS (or EIFS, Figure 2After DIFS is taken as an example), a value is randomly selected in the contention window (CW) as the value of the backoff counter to start backing off. When the value of the backoff counter backs off to zero, a data frame is sent. The data frame carries the NAV information. After receiving the data frame, other devices update their own NAV based on the duration field in the data frame, indicating that the channel is busy during this period of time. If there is data to be sent, it is necessary to delay and wait. The receiving device correctly receives the data frame, waits for SIFS, and then sends an ACK frame to the sending device. When the ACK frame is sent, the channel becomes idle. After waiting for DIFS time, other devices that need to send data begin to compete for the channel using the backoff algorithm. The device whose backoff counter first decreases to 0 successfully competes for the channel and begins to send data frames.

[0106] 4. Enhanced distributed channel access (EDCA)

[0107] EDCA is derived from DCF. In DCF, a device has only one contention queue, and all data to be sent is cached in the same queue. In EDCA, a device supports four access categories to distinguish data of different priorities, and each access category maintains an independent set of channel contention parameters. The four different access categories have priorities from high to low: AC_VO (Voice), AC_VI (Video), AC_BE (Best Effort), and AC_BK (Background), where AC_VO indicates that the access type (or access type) is voice (voice) flow, AC_VI indicates that the access type is video (video) flow, AC_BE indicates that the access type is best effort (best effort) flow, and AC_BK indicates that the access type is background (background) flow.

[0108] In the random backoff process corresponding to each access category (AC), instead of waiting for DIFS, it waits for arbitration interframe space (AIFS), AIFS[AC] = AIFSN[AC]*aSlotTime+aSIFSTime, where arbitration inter frame spacing number (AIFSN) AIFSN is the AIFS number, which depends on the access type. The larger the value, the longer the idle waiting time and the lower the priority. Each AC also corresponds to a different minimum contention window (minimum contention window, CWmin) and maximum contention window CWmax. For access categories with high priority, smaller AIFSN, CWmin and CWmax parameters can be assigned, and for access categories with low priority, larger AIFSN, CWmin and CWmax parameters can be assigned, thereby increasing the sending opportunities of high-priority services and reducing the sending opportunities of low-priority services. Optionally, the minimum value of AIFSN is 2.

[0109] An existing design is that multiple devices compete for channels through DCF or EDCA, and device 1 whose backoff counter value backs off to 0 (also known as successful competition) transfers the channel to the target device through a frame (for example, an RTS frame). The target device (for example, an AP) centrally schedules the uplink or downlink transmission of each device in the BSS to improve the channel utilization efficiency.

[0110] In this way, when only device 1 successfully competes in the BSS, the channel can be transferred to the target device in time through the above-mentioned RTS frame. However, if there are other devices that also have data to send and generate the same random backoff counter value as device 1, then the backoff counter values ​​of multiple devices that generate the same backoff counter value may back off to 0 at the same time, and then send the above-mentioned RTS frame at the same time. At this time, the RTS frames sent by each device will fail due to the collision. After the transmission fails, each device will select a random number within a larger contention window for backoff. However, the device's selection of the backoff counter value is random, and there is always the possibility that multiple devices have the same value. If device 1 continuously and repeatedly collides with other devices and continuously selects the backoff counter value for backoff, it will cause a long delay.

[0111] In view of this, the present application provides a channel access method and apparatus, in which all information contained in the first frame sent by the device when the backoff counter value is zero is pre-set and will not change due to different sending devices. Therefore, even if the backoff counters of multiple devices back off to zero at the same time and the first frame is sent to the target device at the same time, no collision will occur, which effectively avoids the delay caused by the collision, shortens the time for the target device to access the channel, and improves the channel competition efficiency.

[0112] Next, through Figures 3 to 9 The channel access method of the present application is introduced in detail. The embodiments shown in the present application illustrate the channel access method provided by the present application from the perspective of device interaction. The specific form and quantity of each device shown therein are only examples and should not constitute any limitation on the implementation of the method provided by the present application.

[0113] Figure 3 A schematic flow chart of a channel access method 300 provided in an embodiment of the present application, which can be applied to Figure 1 The communication system shown. The method 300 specifically includes the following steps:

[0114] S301: The first device executes a backoff process.

[0115] S302. When determining that the value of the backoff counter is zero, the first device sends a first frame to the second device. The protocol data unit PPDU format of the first frame is a set format. The frame control field, transmission duration field, address field and scrambling code seed included in the first frame are all set values. The first frame is used to transfer the channel scheduling right to the second device; correspondingly, the second device receives the first frame.

[0116] S303: The second device sends data or a trigger frame, where the trigger frame is used to schedule uplink data.

[0117] Optionally, the first device may be a STA, and the second device may be an AP, but this application is not limited to this.

[0118] It should be understood that the first device and the second device belong to the same BSS. After receiving the first frame, the second device has the scheduling right of the channel for which the first device has competed. The second device can send data or trigger frames to any device in the BSS. The device that receives the data or trigger frame can be the first device or other devices in the BSS. This application does not limit this.

[0119] It should also be understood that the PPDU format included in the first frame described in the embodiment of the present application is a set format, and the frame control field, transmission duration field, address field and scrambling code seed are all set values, which means that the format and content of the first frame are pre-set, and the PPDU format, frame control field, transmission duration field, address field and scrambling code seed in the first frame sent by any two devices are the same.

[0120] In an embodiment of the present application, when the first device determines that the value of the backoff counter is zero, it sends a first frame to the second device, in which the PPDU format is a set format, and the frame type field, the transmission duration field, the address field, and the scrambling code seed are all set values. Since all information contained in the first frame is pre-set and will not change with the different devices sending the first frame, when there are multiple devices sending the first frame to the second device at the same time, for the second device, receiving multiple first frames is equivalent to receiving a multipath signal of the first frame sent by the same device. After receiving the first frame, the second device becomes a transmission opportunity (TXOP) holder and has the right to schedule the channel. It can send data to other devices, or schedule other devices to send uplink data by triggering frames.

[0121] Therefore, in the method provided in the embodiment of the present application, when the first device successfully competes for the channel (i.e., the backoff counter value returns to zero), the channel scheduling right is transferred to the second device through a first frame with a fixed format and content. Since the first frame does not change with different sending devices, when there are multiple devices that successfully compete to send the first frame at the same time, the second device can still normally receive multiple first frames sent by multiple devices, thereby avoiding the delay caused by each device reselecting the contention window for backing off after the collision of the first frame, which is beneficial to shortening the time for the second device to access the channel and improving the efficiency of channel competition.

[0122] It should be understood that the above-mentioned "backoff process" refers to the process that the first device needs to execute after a frame (for example, a data frame or a management frame) is to be sent and / or arrives at the first service period of the first device. The backoff process includes: detecting the channel status, waiting for a specific time (DIFS or EIFS) when it is detected that the channel is in a busy state, opening a contention window to select a backoff counter value after detecting that the channel is idle DIFS or EIFS, and after opening the contention window, the backoff counter value is reduced by 1 every time the channel is detected to be idle for a time slot, etc. For example, it can be the above-mentioned DCF or EDCA process, but this application is not limited to this.

[0123] As an optional embodiment, the PPDU format of the first frame may be a non-high throughput presentation protocol data unit (non-HT PPDU) format or a non-high throughput duplicate presentation protocol data unit (non-HT duplicate PPDU) format.

[0124] It should be understood that the first frame includes a physical layer (PHY) structure and a MAC layer structure. The PPDU format provided in the embodiment of the present application is a limitation on the format of the physical layer of the first frame. The PPDU format is the encapsulation format of the frame generated by the physical layer to the MAC layer.

[0125] In a possible implementation, the scrambler seed included in the first frame does not carry bandwidth information.

[0126] In the embodiment of the present application, since the idle channel bandwidths detected by various devices executing the backoff process may be different, the purpose of setting the scrambling code seed not to carry bandwidth information is to ensure that the first frame sent by any device when the backoff counter value is zero is the same frame.

[0127] In another possible implementation manner, the scrambling code seed included in the first frame carries set bandwidth information.

[0128] It should be understood that the set bandwidth information carried by the first frame does not necessarily match the bandwidth of the current TXOP. Therefore, regardless of whether the first frame carries the bandwidth information, the second device can obtain the bandwidth of the current TXOP in the following manner:

[0129] Method 1: Detect the bandwidth of the first frame and use the bandwidth of the first frame as the bandwidth of the current TXOP.

[0130] Method 2: The bandwidth of the idle channel detected within the point coordination function interframe space (PIFS) duration before receiving the first frame is used as the bandwidth of the current TXOP.

[0131] Method 3: The bandwidth of the idle channel detected within the SIFS or PIFS duration after receiving the first frame is used as the bandwidth of the current TXOP.

[0132] Method 4: After receiving the first frame, execute the backoff process, and use the bandwidth of the idle channel detected after the backoff is completed as the bandwidth of the current TXOP. The value of the backoff counter can be set to zero when the second device backs off after receiving the first frame. The reason is that after other devices other than the second device intercept the first frame, they will set the network allocation vector (NAV) according to the transmission duration field in the first frame, thereby freezing the backoff counter time of other devices and temporarily not participating in the channel competition. Therefore, in order to shorten the backoff duration of the second device, the backoff counter value can be directly set to zero. However, it should be understood that the value of the backoff counter when the second device backs off after receiving the first frame can also be selected from the current existing value or any other value, and this application does not limit this.

[0133] Optionally, in the above four methods, the second device can obtain bandwidth information through packet detection or energy detection (energy detector, ED), and the present application does not specifically limit the bandwidth detection method of the second device.

[0134] Optionally, the first frame may be a frame that requires a response or a frame that does not require a response, which is not specifically limited in this application. The frame structure of the first frame may be as follows: Figure 4 or Figure 5 shown.

[0135] Figure 4 A typical control frame structure is shown in FIG. Figure 4 As shown, the frame includes: a frame control field, a transmission duration field, a receiver address (RA) field, a transmitter address (TA) field and a frame check sequence (FCS).

[0136] In one implementation, Figure 4 In the control frame of the structure shown, the transmit address (RA) field identifies the MAC address of the device that sends the frame, and the receive address (TA) field identifies the MAC address of the device that receives the frame. After receiving the frame, any device can reply a response frame to the device that sends the frame based on the MAC address set in the transmit address (RA) field of the frame.

[0137] Figure 5 Another typical control frame structure is shown in FIG. Figure 5As shown, the frame includes: a frame control field, a transmission duration field, a receiver address (RA) field and a frame check sequence (FCS).

[0138] In one implementation, Figure 5 In the control frame of the structure shown, only the MAC address of the device receiving the frame is identified by the receiving address (RA) field. The control frame can usually be used as a response frame to a frame that requires a response, or as a control frame that does not require a response from the receiving device.

[0139] Figure 6 Shown is applicable to the above Figure 4 and Figure 5 The structure of the frame control field in Figure 6 As shown, the frame control field includes: a protocol version field, a type field, a subtype field, a to DS field, a from DS field, a more fragments field, a retry field, a power management field, a more data field, a protected frame field, and a high throughput control (+HTC) field.

[0140] It should be understood that Figure 4 , Figure 5 The frame structure shown, and Figure 6 The shown applies to Figure 4 and Figure 5 The structures of the frame control fields in the PPDU are all existing and common structures. The first frame provided by the present application sets the frame control field, transmission duration field and address field included in the first frame to fixed values ​​while the PPDU format is the set format and the scrambling code seed is a fixed value. Among them, the setting of the frame control field and the address field includes the following possible implementation methods:

[0141] The first possible implementation method: the frame structure of the first frame can be as follows Figure 5 As shown, the structure of the frame control can be as follows Figure 6As shown, exemplarily, the type field is used to identify whether the frame is a control frame (01), a data frame (10) or a management frame (00), and the subtype field is used to identify which subtype of the frame type identified by the field type the frame belongs to. In an embodiment of the present application, the type field and / or subtype field in the frame control of the first frame can be set to a value not defined in the prior art, and the remaining fields all maintain the existing settings. Exemplarily, the type field of the first frame can be set to 11, and the subtype field can be set to any value from 0000 to 1111, or the type field of the first frame can be set to 01, and the subtype field can be set to any value from 0000 to 0011 reserved for the current control frame.

[0142] Optionally, the number of bits and specific values ​​corresponding to the type field and subtype field of the present application can also be other arbitrary values, and the present application does not limit this.

[0143] Optionally, the present application may refer to a frame type defined by a value not defined in the prior art as a commonframe, but the present application does not limit this.

[0144] The second possible implementation method: the frame structure of the first frame is as follows: Figure 4 As shown, the structure of the frame control is as follows Figure 6 shown.

[0145] In one case, the type field and subtype field of the first frame are values ​​defined in the technology, for example, the type field is 01 and the subtype field is 1011, indicating that the type of the first frame is an RTS frame in a control frame. In the existing standard, the receiving address field is the MAC address of the device receiving the frame, and the sending address field is the MAC address of the device sending the frame. In the first frame provided by the present application, the receiving address field is the MAC address of the second device, and the sending address field is set to a set MAC address. The second device can identify this frame as the first frame for handing over channel scheduling rights based on the difference between the setting of the sending address and the prior art.

[0146] In another case, the type field and / or subtype field in the frame control of the first frame provided in the present application can be set to an undefined value in the prior art described in the above-mentioned first possible implementation method, the receiving address field is the MAC address of the second device, and the sending address field is set to a set MAC address.

[0147] Optionally, the MAC address set in the sending address field can be any broadcast address, multicast address, or address of other devices that do not interact with the second device, and this application does not make specific limitations on this.

[0148] A third possible implementation method: the values ​​of the To DS field, From DS field, MoreFragments field, Retry field, Power Management field, More Data field and Protected Frame field in the existing control frame are all 0. In the first frame provided by the present application, in the To DS field, From DS field, More Fragments field, Retry field, Power Management field, More Data field and ProtectedFrame field in the frame control field of the first frame, at least one field is specified and set to 1. The second device can identify this frame as the first frame for transferring channel scheduling rights based on the difference between the value of the specified field and the value of the field in the prior art.

[0149] Optionally, the frame type field and subtype field in the first frame can be values ​​defined in the prior art, for example, the type field is 01 and the subtype field is 1100, indicating that the type of the first frame is a CTS frame in the control frame, or, for example, the type field is 01 and the subtype field is 1011, indicating that the type of the first frame is an RTS frame in the control frame.

[0150] Optionally, the third possible implementation manner described above may also be combined with any of the situations described in the first possible implementation manner and the second possible implementation manner, and this application does not limit this.

[0151] The setting value of the transmission duration field of the first frame provided in this application should be less than the transmission opportunity limit (TXOP limit). The setting of this value includes the following possible implementation methods:

[0152] A first possible implementation manner: when the first frame is a frame that does not require a response, the value of the transmission duration field in the first frame can be set to a SIFS duration or a PIFS duration plus a MU-RTS frame transmission duration.

[0153] A second possible implementation method: When the first frame is a frame that requires a response, the value of the transmission duration field in the first frame can be set to the duration of a SIFS or a PIFS, plus the duration of a response frame, plus the duration of a SIFS or a PIFS and the sending duration of a MU-RTS frame.

[0154] It should be understood that the first frame is a frame for transferring channel scheduling rights sent by the first device to the second device when the backoff counter value backs off to zero, that is, when the channel competition is successful. After receiving the first frame, the second device becomes the transmission opportunity holder (TXOP holder). After receiving the first frame and waiting for a SIFS period, the second device can send a MU-RTS frame to one or more devices to reserve channels and better protect the current channel.

[0155] It should also be understood that when setting the transmission duration of the first frame, on the one hand, it is necessary to consider avoiding channel competition initiated by some devices that are hidden nodes of the second device after the first frame ends, resulting in a conflict with the frame to be sent by the second device after receiving the first frame. On the other hand, since the first frame can be sent by multiple devices at the same time, its coverage may exceed the coverage of the device that actually communicates data with the second device next, resulting in overprotection. Therefore, the value of the transmission duration field is not easy to be too large. Exemplarily, according to the transmission duration setting method provided in the embodiment of the present application, the duration of the transmission duration field of the first frame is about 100us, which is a relatively small time value, and the duration of a TXOP is generally allowed to be set to 3-5ms. The method provided in the embodiment of the present application is conducive to avoiding unnecessary waiting of other devices caused by excessive channel protection duration, and is conducive to improving channel utilization.

[0156] It is worth noting that although there are many possible implementation methods for the settings of the PPDU format, scrambling code seed, frame control field, address field and transmission duration field of the first frame described above, for any device sending the first frame, the PPDU format of the first frame, the frame structure of the first frame, the frame control field in the first frame, the transmission duration field, the address field and the scrambling code seed values ​​are all specified by the protocol, unique, and do not change with different sending devices.

[0157] As an optional embodiment, the first device belongs to the first group, the PPDU format of the first frame sent by different devices in the first group is the same, and the following fields included in the first frame sent by different devices in the first group have the same values: frame control field, transmission duration field, address field and scrambling code seed.

[0158] It should be understood that the devices in the first group may be devices with the same service or the same type of service, and the devices in the first group belong to the same BSS. A BSS may include one or more groups, and this application does not limit this.

[0159] As an optional embodiment, the above-mentioned first group may also include a third device, and the second device receives a second frame sent by the third device, and the PPDU format, frame control field, transmission duration field, address field and scrambling code seed in the second frame are the same as those in the first frame.

[0160] It should be understood that the second frame here is essentially the same frame as the first frame. It is named the second frame here only for the convenience of description. The similarities are reflected in the PPDU format, frame control field, transmission duration field, address field and scrambling code seed. In other words, each bit in the bit sequence of the first frame and the second frame is the same.

[0161] In a possible implementation, the first device belongs to the first group and is configured by the second device through first configuration information. The implementation includes: the first device receives the first configuration information from the second device, and the first configuration information is used to indicate that the first device belongs to the first group.

[0162] In another possible implementation, the first device belongs to the first group, which is determined after the first device interacts with the second device, and its implementation method includes: the first device receives group indication information from the second device, and the group indication information includes the group identifier of at least one group; the first device sends a first request to the second device based on the group indication information, and the first request is used to request to join the first group in at least one group; the first device receives a first response from the second device to the first request.

[0163] It should be understood that when the above-mentioned first response is a response to the success of the first request, it means that the second device agrees that the first device joins the first group.

[0164] As an optional embodiment, the first group is grouped through a broadcast target wake time (B-TWT) mechanism or a restricted target wake time (R-TWT) mechanism.

[0165] Figure 7 Taking the second device as an AP as an example, the process of the AP establishing a group through the B-TWT mechanism or the R-TWT mechanism is shown. Figure 7 As shown, the AP will periodically broadcast the group identifier (for example, TWT ID) and the service period corresponding to the group in the Beacon frame. The STA receives the Beacon frame and sends a request to the AP to join the group. After receiving a successful response from the AP, it is considered that the STA has joined a group. If the service period corresponding to the group is Figure 7 If the STA is in service period 1 in the AP, then the STA wakes up at the time corresponding to service period 1, competes for channels, or receives trigger frames or data frames sent by the AP. After completing the interaction with the AP, the STA enters the sleep state and wakes up again when the next service time arrives, and so on.

[0166] It should be understood that the group to which a STA belongs and the service time of the group are not fixed. The AP broadcasts once every certain period of time, and the group identifier and service period may be different each time. The STA can join or leave the group by interacting with the AP.

[0167] As an optional embodiment, the first service period of the first device can be configured through second configuration information, and its implementation method includes: the first device receives the second configuration information, and the second configuration information is used to configure the first service period; the first device executes the backoff process, including: the first device executes the backoff process within the first service period.

[0168] It should be understood that the first service period is a period during which the first device is allowed to compete for the channel. When the first service period arrives, the first device can participate in the channel competition to assist the second device in obtaining the channel scheduling right as soon as possible.

[0169] Optionally, the first device provided in the embodiment of the present application may be a STA or an AP, and the second device may also be a STA or an AP, without specific limitation.

[0170] In this patent solution, when the second device is an AP, the first device can also be an AP, that is, the AP of the first device sends the first frame, and the receiving address of the first frame is set to the MAC address of the AP. After sending the first frame, the AP of the second device becomes the TXOP holder. In this case, the first device and the second device are the same device, that is, both are APs.

[0171] Below, the channel access method provided by the present application is further described in detail by taking the first device as STA 1, the second device as AP, and the BSS where the STA 1 and the AP are located also includes STA 2 and STA 3. STA 1, STA 2, and STA 3 join the same site group through negotiation with the AP. In the subsequent description, the site group is referred to as site group 1, and the AP allocates one or more service time periods to the site group 1. Figure 8 The number of STAs and the number of service periods shown in are exemplary only and do not constitute specific limitations of the embodiments of the present application.

[0172] Figure 8 The implementation process of a channel access method provided by the present application is exemplarily shown. Figure 8 As shown in FIG. 1 , STA 1, STA 2, and STA 3 start competing for the channel after service period 1 arrives. Taking STA 1 as an example, STA 1 starts backing off after detecting that the channel is busy and waiting for the channel to be idle for a DIFS period. When the randomly selected backoff counter value is zero, the first frame is sent to the AP, as shown in FIG. Figure 8As shown in the figure, the backoff counters of STA 1 and STA 2 back off to zero at the same time at time t1, then STA 1 and STA 2 send the first frame to AP at the same time at time t1, and after receiving any of the first frames, STA 3 updates its own NAV information based on the NAV information carried in the transmission duration field in the first frame, indicating that the channel is busy during this period, and the backoff counter value is frozen ( Figure 8 The shaded portion in the backoff time of STA 3 indicates the time when the backoff counter is frozen), and the backoff will not continue.

[0173] If the first frame is a frame that does not require a response, the AP becomes the TXOP holder after receiving the first frame, and sends a data frame to STA 1 after waiting for a SIFS. After STA 1 correctly receives the data frame and waits for a SIFS, it sends a confirmation frame to the AP.

[0174] If the first frame is a frame that requires a response, the AP sends a response frame after receiving the first frame and waiting for a SIFS period, and then waits for a SIFS period to send a data frame to STA 1. After STA 1 correctly receives the data frame and waits for a SIFS period, it sends a confirmation frame to the AP.

[0175] In a possible implementation, the frame structure of the response frame sent by the AP after receiving the first frame may be as follows: Figure 5 As shown, the receiving address field of the response frame may be a set value. Optionally, the receiving address field of the response frame may be the same as the sending address field of the first frame received by the AP, but this application does not limit this.

[0176] Optionally, the STA to which the AP sends data frames can be any STA, not limited to the STA in site group 1, and the AP can send data frames to one or more STAs at the same time, which is not limited in this application.

[0177] Optionally, the duration that the AP waits before sending a data frame may also be a PIFS duration, and the AP may detect an idle channel within the PIFS duration to obtain a bandwidth for the TXOP.

[0178] Optionally, site group 1 may include all members in a BSS, that is, a BSS may be regarded as a site group. Site group 1 may also be a site group including an AP and some STAs in the BSS. A BSS may also include multiple site groups. This application does not specifically limit the size of the site group.

[0179] In a possible implementation, the AP also participates in channel contention, that is, the AP also performs a backoff process in service period 1 and sends the first frame when the backoff counter value is zero. The AP becomes a TXOP holder after sending the first frame. After sending the first frame, the AP sends a response frame to the first frame after waiting for a SIFS period, or directly sends a data frame.

[0180] Fig. 9 The implementation process of another channel access method provided by the present application is exemplified. Fig. 9 STA4, STA 5, STA 6 and STA 7 belong to site group 2. The target site of site group 2 in service period 2 is STA 4, and the target site in service period 3 is STA 6. It should be understood that after successfully competing for the channel, all STAs in the site group will transfer the channel scheduling right to the target site.

[0181] like Fig. 9 As shown in FIG. 1 , STA 5, STA 6, and STA 7 start competing for the channel after service period 2 arrives. Taking STA 5 as an example, STA 5 starts backing off after detecting that the channel is busy and waiting for the channel to be idle for a DIFS period. When the randomly selected backoff counter value is zero, the first frame is sent to the AP, as shown in FIG. Fig. 9 As shown, the backoff counters of STA 5 and STA 6 back off to zero at the same time at time t2, then STA5 and STA 6 send the first frame to STA 4 at the same time at time t1. After receiving any of the first frames, STA 7 updates its own NAV information based on the NAV information carried in the transmission duration field in the first frame, indicating that the channel is busy during this period, and the backoff counter value is frozen ( Fig. 9 The shaded portion in the backoff time 1 of STA 7 indicates the time when the backoff counter is frozen), and the backoff will not continue.

[0182] If the first frame is a frame that does not require a response, STA 4 becomes the TXOP holder after receiving the first frame, and sends a data frame to STA1 after waiting for a SIFS. After STA 5 correctly receives the data frame and waits for a SIFS, it sends a confirmation frame to the AP.

[0183] If the first frame is a frame that requires a response, STA 4 sends a response frame after receiving the first frame and waiting for a SIFS period, and then waits for a SIFS period to send a data frame to STA 5. After STA 5 correctly receives the data frame and waits for a SIFS period, it sends a confirmation frame to the AP.

[0184] like Fig. 9As shown, STA 4, STA 5 and STA 7 start to compete for the channel after service period 3 arrives. Taking STA 5 as an example, STA 5 starts to back off after detecting that the channel is busy and waiting for the channel to be idle for a DIFS period. When the randomly selected backoff counter value is zero, it sends the first frame to the AP. The backoff counters of STA 5 and STA 7 back off to zero at the same time at time t3. Then STA 5 and STA 7 send the first frame to STA 6 at the same time at time t1. After receiving any first frame, STA 4 updates its own NAV information based on the NAV information carried in the transmission duration field in the first frame, indicating that the channel is busy during this period, and the backoff counter value is frozen ( Fig. 9 The shaded portion in the backoff time of STA 4 indicates the time when the backoff counter is frozen), and the backoff will not continue.

[0185] If the first frame is a frame that does not require a response, STA 6 becomes the TXOP holder after receiving the first frame, and sends a data frame to STA1 after waiting for a SIFS. After STA 5 correctly receives the data frame and waits for a SIFS, it sends a confirmation frame to the AP.

[0186] If the first frame is a frame that requires a response, STA 6 sends a response frame after receiving the first frame and waiting for a SIFS period, and then waits for a SIFS period to send a data frame to STA 5. After STA 5 correctly receives the data frame and waits for a SIFS period, it sends a confirmation frame to the AP.

[0187] The second device described in the above embodiment may be Fig. 9 STA 4 corresponding to service period 2 or STA6 corresponding to service period 3, the first device may be Fig. 9 STA 5 corresponding to service period 2 or STA 5 corresponding to service period 3, but this application is not limited to this.

[0188] A site group consisting of multiple STAs can be established in the following ways:

[0189] Method 1: Multiple STAs join the same site group through negotiation with the AP. The AP is responsible for allocating service time periods for the site group and specifying target sites for each service time period. Figure 7 The B-TWT mechanism or R-TWT mechanism shown in the figure, or the AP directly specifies the group to which each STA belongs through configuration information. This application does not make specific limitations on this process.

[0190] Method 2: One of the multiple STAs acts as a leader (header), and other STAs join the site group established by the header STA through negotiation with the header STA. The header STA allocates service time periods to the site group and specifies a target site for each service time period.

[0191] Optionally, the negotiation process between other STAs and the header STA may be a method in which other STAs apply to the header STA to join, or a method in which the header STA directly configures each STA, which is not limited in this application.

[0192] In a possible implementation, the header STA may be the target station for part or all of the service periods in the station group.

[0193] Method 3: Multiple stations negotiate to establish a station group. For example, STA 1 and STA 2 first negotiate to establish station group 3. If STA 3 wants to join station group 3, it needs to obtain the consent of STA 1 and STA 2 respectively. After STA 3 joins station group 3, if STA 4 wants to join the station group, it needs to obtain the consent of STA 1, STA 2 and STA 3 respectively, and so on. This application does not limit the number of STAs in a station group.

[0194] In a possible implementation, the target site of a site group formed by negotiation between two or more sites may also be generated by negotiation between two or more sites. The generation of the target site requires the consent of all STAs in the site group.

[0195] In a possible implementation, the service period of the site group formed by negotiation between multiple sites can be specified by the target site or determined by negotiation between members of the site group. It should be understood that the service time corresponding to each target site should not overlap.

[0196] Optionally, the method provided in the embodiment of the present application may be applicable to a peer-to-peer (P2P) site or a mesh (MESH) site, but the present application is not limited to this.

[0197] Combination of the above Figures 1 to 9 , describes in detail the channel access method of the embodiment of the present application, and the following is combined with Fig.10 and Fig.11, a device for implementing the channel access method is described in detail. The channel access device includes a module or unit for executing each part of the above embodiment. Each module or unit can be software, hardware, or a combination of software and hardware. The following only briefly illustrates the channel access device. For the implementation details of the scheme, please refer to the description of the above method embodiment, which will not be repeated below.

[0198] Fig.10 1 is a schematic block diagram of a channel access device 1000 provided in an embodiment of the present application. Fig.10 As shown, the device 1000 includes: a processing module 1001 and a transceiver module 1002 .

[0199] In a possible implementation, the channel access apparatus 1000 is used to execute the steps and processes corresponding to the first device in the above method 300.

[0200] Among them, the processing module 1001 is used to: execute the backoff process; the transceiver module 1002 is used to: when the value of the backoff counter is zero, send a first frame to the second device, the protocol data unit PPDU format of the first frame is a set format, and the frame control field, transmission duration field, address field and scrambling code seed included in the first frame are all set values, and the first frame is used to transfer the channel scheduling right to the second device.

[0201] Optionally, the address field includes a receiving address field and a sending address field, the receiving address field is the MAC address of the second device, and the sending address field is a set MAC address.

[0202] Optionally, at least one of the following fields in the frame control field is set to 1: To DS field, From DS field, More Fragments field, Retry field, Power Management field, More Data field, and Protected Frame field.

[0203] Optionally, the first device belongs to the first group, the PPDU format of the first frame sent by different devices in the first group is the same, and the following fields included in the first frame sent by different devices in the first group have the same values: frame control field, transmission duration field, address field and scrambling code seed.

[0204] Optionally, the transceiver module 1002 is further used to: receive first configuration information from the second device, where the first configuration information is used to indicate that the first device belongs to the first group.

[0205] Optionally, the transceiver module 1002 is also used to: receive group indication information from the second device, the group indication information including the group identifier of at least one group; based on the group indication information, send a first request to the second device, the first request being used to request to join a first group in at least one group; and receive a first response from the second device to the first request.

[0206] Optionally, the first group is grouped by a broadcast target wake-up time B-TWT mechanism or a restricted target wake-up time R-TWT mechanism.

[0207] Optionally, the transceiver module 1002 is further used to: receive second configuration information, where the second configuration information is used to configure the first service period; and the processing module 1001 is specifically used to: execute the backoff process within the first service period.

[0208] Optionally, the first device is a station access point AP or a non-access point station non-AP STA.

[0209] Optionally, the first frame is a request to send RTS frame or a clear to send CTS frame.

[0210] Optionally, the PPDU format is a non-HT PPDU or a non-HTduplicate PPDU.

[0211] In another possible implementation, the channel access apparatus 1000 is used to execute the steps and processes corresponding to the second device in the above method 300.

[0212] Among them, the transceiver module 1002 is used to: receive the first frame, the protocol data unit PPDU format of the first frame is the set format, the frame control field, transmission duration field, address field and scrambling code seed included in the first frame are all set values, and the first frame is used to transfer the channel scheduling right to the second device; and, send data or trigger frame, the trigger frame is used to schedule uplink data.

[0213] Optionally, the transceiver module 1002 is further used to: receive a second frame sent by a third device, the PPDU format, frame control field, transmission duration field, address field and scrambling code seed of the second frame are the same as those of the first frame.

[0214] Optionally, the first frame is a frame requiring a response, the address field includes a receiving address field and a sending address field, the receiving address field is a media access control MAC address of the second device, and the sending address field is a set MAC address.

[0215] Optionally, at least one of the following fields in the frame control field is set to 1: To DS field, From DS field, More Fragments field, Retry field, Power Management field, More Data field, and Protected Frame field.

[0216] Optionally, the transceiver module 1002 is further used to: send first configuration information to the first device, where the first configuration information is used to indicate that the first device belongs to the first group.

[0217] Optionally, the transceiver module 1002 is also used to: send group indication information, the group indication information includes a group identifier of at least one group; receive a first request from a first device, the first request is used to request to join a first group in at least one group; and send a first response to the first request to the first device.

[0218] Optionally, the first group is grouped by a broadcast target wake-up time B-TWT mechanism or a restricted target wake-up time R-TWT mechanism.

[0219] Optionally, the first device belongs to the first group, the PPDU format of the first frame sent by different devices in the first group is the same, and the following fields included in the first frame sent by different devices in the first group have the same values: frame control field, transmission duration field, address field and scrambling code seed.

[0220] Optionally, the transceiver module 1002 is further used to: send second configuration information to the first device, where the second configuration information is used to configure the first service period; and the first device performs a backoff process within the first service period.

[0221] Optionally, the second device is an access point AP or a non-access point station non-AP STA.

[0222] Optionally, the first frame is a request to send RTS frame or a clear to send CTS frame.

[0223] Optionally, the PPDU format is a non-HT PPDU or a non-HTduplicate PPDU.

[0224] It should be understood that the device 1000 here is embodied in the form of a functional module. The term "module" here may refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a proprietary processor or a group processor, etc.) and a memory for executing one or more software or firmware programs, a merged logic circuit and / or other suitable components that support the described functions. In an optional example, those skilled in the art can understand that the device 1000 can be specifically the first device or the second device in the above-mentioned embodiment, and the device 1000 can be used to execute the various processes and / or steps corresponding to the first device or the second device in the above-mentioned method embodiment. To avoid repetition, it will not be repeated here.

[0225] The above-mentioned device 1000 has the function of implementing the corresponding steps performed by the first device or the second device in the above-mentioned method; the above-mentioned function can be implemented by hardware, or by hardware executing the corresponding software implementation. The hardware or software includes one or more modules corresponding to the above-mentioned functions. For example, the above-mentioned transceiver module 1002 may include a sending module and a receiving module, the sending module can be used to implement the various steps and / or processes for performing the sending action corresponding to the above-mentioned transceiver module, and the receiving module can be used to implement the various steps and / or processes for performing the receiving action corresponding to the above-mentioned transceiver module. The sending module can be replaced by a transmitter, and the receiving module can be replaced by a receiver, respectively performing the sending and receiving operations and related processing operations in each method embodiment.

[0226] In the embodiments of the present application, Fig.10 The device 1000 may also be a chip, such as a SOC.

[0227] Fig.11 A schematic block diagram of a channel access device 1100 provided in an embodiment of the present application is shown. The device 1100 includes a processor 1101, a transceiver 1102, and a memory 1103. The processor 1101, the transceiver 1102, and the memory 1103 communicate with each other through an internal connection path, the memory 1103 is used to store instructions, and the processor 1101 is used to execute the instructions stored in the memory 1103 to control the transceiver 1102 to send signals and / or receive signals.

[0228] It should be understood that the device 1100 can be specifically the first device or the second device in the above-mentioned embodiment, and can be used to execute the various steps and / or processes corresponding to the first device or the second device in the above-mentioned method embodiment. Optionally, the memory 1103 may include a read-only memory and a random access memory, and provide instructions and data to the processor. A part of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type. The processor 1101 may be used to execute instructions stored in the memory, and when the processor 1101 executes instructions stored in the memory, the processor 1101 is used to execute the various steps and / or processes of the above-mentioned method embodiment. The transceiver 1102 may include a transmitter and a receiver, the transmitter may be used to implement the various steps and / or processes corresponding to the above-mentioned transceiver for performing the sending action, and the receiver may be used to implement the various steps and / or processes corresponding to the above-mentioned transceiver for performing the receiving action.

[0229] It should be understood that in the embodiments of the present application, the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0230] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software modules in a processor for execution. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor executes the instructions in the memory, and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0231] The present application also provides a computer-readable storage medium, which is used to store a computer program, and the computer program is used to implement the method shown in the above method embodiment.

[0232] The present application also provides a computer program product, which includes a computer program (also referred to as code or instruction). When the computer program runs on a computer, the computer can execute the method shown in the above method embodiment.

[0233] Those of ordinary skill in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0234] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and modules described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0235] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0236] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0237] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0238] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0239] The above is only a specific implementation of the present application, but the protection scope of the embodiments of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the embodiments of the present application, which should be included in the protection scope of the embodiments of the present application. Therefore, the protection scope of the embodiments of the present application should be based on the protection scope of the claims.

Claims

1. A channel access method, characterized in that: include: The first device performs a backoff procedure; When the value of the backoff counter is zero, a first frame is sent to the second device, the protocol data unit PPDU format of the first frame is a set format, the frame control field, transmission duration field, address field and scrambling code seed included in the first frame are all set values, and the first frame is used to transfer the channel scheduling right to the second device.

2. The method according to claim 1, characterized in that The address field includes a receiving address field and a sending address field, the receiving address field is the MAC address of the second device, and the sending address field is a set MAC address.

3. The method according to claim 1 or 2, characterized in that: At least one of the following fields in the frame control field is set to 1: To DS field, From DS field, More Fragments field, Retry field, Power Management field, More Data field, and Protected Frame field.

4. The method according to any one of claims 1 to 3, characterized in that The first device belongs to the first group, the PPDU format of the first frame sent by different devices in the first group is the same, and the following fields included in the first frame sent by different devices in the first group have the same values: frame control field, transmission duration field, address field and scrambling code seed.

5. The method according to claim 4, characterized in that The method further comprises: The first device receives first configuration information from the second device, where the first configuration information is used to indicate that the first device belongs to the first group.

6. The method according to claim 4, characterized in that The method further comprises: The first device receives grouping indication information from the second device, where the grouping indication information includes a group identifier of at least one group; The first device sends a first request to the second device based on the grouping indication information, where the first request is used to request to join a first group in the at least one group; The first device receives a first response to the first request from the second device.

7. The method according to claim 6, characterized in that The first group is grouped by a broadcast target wake-up time B-TWT mechanism or a restricted target wake-up time R-TWT mechanism.

8. The method according to any one of claims 1 to 6, characterized in that The method further comprises: The first device receives second configuration information, where the second configuration information is used to configure a first service period; The first device performs a backoff process, including: The first device performs a backoff procedure during the first service period.

9. The method according to any one of claims 1 to 8, characterized in that The first device is an access point AP or a non-access point station non-AP STA.

10. The method according to any one of claims 1 to 9, characterized in that The first frame is a request to send RTS frame or a clear to send CTS frame.

11. The method according to any one of claims 1 to 10, characterized in that The PPDU format is a non-HT PPDU or a non-HT duplicate PPDU.

12. A channel access method, characterized in that: include: The second device receives a first frame, wherein a protocol data unit PPDU format of the first frame is a set format, a frame control field, a transmission duration field, an address field, and a scrambling code seed included in the first frame are all set values, and the first frame is used to transfer the channel scheduling right to the second device; The second device sends data or a trigger frame, where the trigger frame is used to schedule uplink data.

13. The method according to claim 12, characterized in that The method also includes: The second device receives a second frame sent by the third device, and the PPDU format, frame control field, transmission duration field, address field and scrambling code seed of the second frame are the same as those of the first frame.

14. The method according to claim 12 or 13, characterized in that The address field includes a receiving address field and a sending address field, the receiving address field is a media access control MAC address of the second device, and the sending address field is a set MAC address.

15. The method according to any one of claims 12 to 14, characterized in that At least one of the following fields in the frame control field is set to 1: To DS field, From DS field, More Fragments field, Retry field, Power Management field, More Data field, and Protected Frame field.

16. The method according to any one of claims 12 to 15, characterized in that The method further comprises: The second device sends first configuration information to the first device, where the first configuration information is used to indicate that the first device belongs to a first group.

17. The method according to any one of claims 12 to 15, characterized in that The method further comprises: The second device sends grouping indication information, where the grouping indication information includes a group identifier of at least one group; The second device receives a first request from the first device, where the first request is used to request to join a first group of the at least one group; The second device sends a first response to the first request to the first device.

18. The method according to claim 17, characterized in that The first group is grouped by a broadcast target wake-up time B-TWT mechanism or a restricted target wake-up time R-TWT mechanism.

19. The method according to any one of claims 12 to 17, characterized in that The first device belongs to the first group, the PPDU format of the first frame sent by different devices in the first group is the same, and the following fields included in the first frame sent by different devices in the first group have the same values: frame control field, transmission duration field, address field and scrambling code seed.

20. The method according to any one of claims 12 to 17, characterized in that The method further comprises: The second device sends second configuration information to the first device, where the second configuration information is used to configure the first service period; The first device performs a backoff procedure during the first service period.

21. The method according to any one of claims 12 to 20, characterized in that The second device is an access point AP or a non-access point station non-AP STA.

22. The method according to any one of claims 12 to 21, characterized in that The first frame is a request to send RTS frame or a clear to send CTS frame.

23. The method according to any one of claims 12 to 22, characterized in that The PPDU format is a non-HT PPDU or a non-HT duplicate PPDU.

24. A channel access device, characterized in that: A module comprising the method of any one of claims 1 to 11, or a module comprising the method of any one of claims 12 to 23.

25. A channel access device, characterized in that: include: A processor, wherein the processor is coupled to a memory, wherein the memory is used to store a computer program, and when the processor calls the computer program, the device executes the method as claimed in any one of claims 1 to 11, or the method as claimed in any one of claims 12 to 23.

26. A computer-readable storage medium, characterized in that: Used to store a computer program, the computer program comprising instructions for implementing the method according to any one of claims 1 to 11, or instructions for implementing the method according to any one of claims 12 to 23.

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