Channel access method and communication device

Abstract

Provided are a channel access method and a communication device, the method comprising: determining backoff time information on the basis of the length of a first time unit, the backoff time information indicating a first duration for a first device to execute backoff, the length of the first time unit being greater than or less than the length of a time slot; and executing a back-off process according to a channel state of a first channel and the back-off time information, the first channel being used for transmitting data of the first device after the back-off is finished. The backoff duration of the second device is determined based on the length of the time unit whose length is greater than or less than the length of the time slot, so that the probability of air interface collision between the first device and other devices in the network can be reduced, and the data transmission delay can be reduced.

Description

Technical Field

[0001] This application relates to the field of communications, and more specifically, to a method and apparatus for channel access. Background Technology

[0002] With the development of communication technology, optical fiber transmission is increasingly being used in communication systems, among which fiber to the room (FTTR) is a crucial component of optical networks. An FTTR system consists of a main device and sub-devices, connected via optical fiber. The main device, acting as an optical network terminal (ONT) or optical network unit (ONU) in a passive optical network (PON), is connected to the optical line terminal (OLT) at the operator's central office via optical fiber.

[0003] In an FTTR system, each device can independently compete for the channel. For example, an enhanced distributed channel access (EDCA) mechanism can be used for backoff and channel preemption, and data can be transmitted after successful channel preemption. Once a device has preempted the channel, other devices can determine the busy / idle state of the channel based on channel monitoring, and can backoff and access the channel if it is idle.

[0004] Under this channel access mechanism, air interface collisions may occur when two devices send data frames. This means that neither device can detect the other's initiation of data frame transmission in time, causing their data packets to interfere with each other and preventing timely data transmission, thus increasing data transmission latency. Therefore, reducing data transmission latency is a problem that needs to be considered. Summary of the Invention

[0005] This application provides a channel access method and communication device that can reduce the probability of air interface collisions, thereby reducing data transmission latency.

[0006] Firstly, a method for channel access is provided, which can be executed by a first device or by a component of the first device (e.g., a chip, circuit, or chip system). The following description assumes execution by the first device.

[0007] The method includes: determining backoff time information based on the length of a first time unit, the backoff time information indicating a first duration for which the first device performs backoff, the length of the first time unit being greater than or less than the length of a time slot; and performing a backoff process according to the channel state of a first channel and the backoff time information, wherein the first channel is used to transmit data of the first device after the backoff ends.

[0008] Based on the above scheme, by determining the backoff time of the second device based on the length of a time unit that is greater than or less than a time slot, the probability of the first device colliding with other devices in the network can be reduced, thereby reducing data transmission latency.

[0009] In some implementations of the first aspect, when the length of the first time unit is greater than the length of a time slot, the length of the first time unit is N times the length of a time slot, where N is an integer greater than or equal to 2.

[0010] In some implementations of the first aspect, the backoff process based on the channel state of the first channel and the backoff time information includes: if the channel state is currently occupied, then after a second duration following the end of the first channel being occupied, a first backoff is performed, wherein the duration of the first backoff is less than or equal to the first duration; wherein the backoff process includes the first backoff.

[0011] In some implementations of the first aspect, the second duration is determined based on the length of the first time unit.

[0012] In some implementations of the first aspect, the second duration is the sum of the product of the length of the first time unit and the number of arbitration frame gaps (AIFSN) and the length of the short frame gap.

[0013] In some implementations of the first aspect, the length of the first time unit is determined according to configuration information, which configures the length of the first time unit to be greater than the length of a time slot, or the configuration information configures the length of the first time unit to be less than the length of a time slot.

[0014] In a second aspect, a communication device is provided. The device may be a first device or a component of the first device (e.g., a chip, circuit, or chip system). The device may have the functions described in the first aspect. For example, the device may include modules, units, or means that perform the operations described in the first aspect. These modules, units, or means may be implemented by software, hardware, or a combination of software and hardware.

[0015] Specifically, the device includes a processing unit, which is configured to: determine backoff time information based on the length of a first time unit, the backoff time information indicating a first duration for which the device performs backoff, the length of the first time unit being greater than or less than the length of a time slot; and perform a backoff process according to the channel state of a first channel and the backoff time information, wherein the first channel is used to transmit data of the device after the backoff ends.

[0016] In some implementations of the second aspect, when the length of the first time unit is greater than the length of a time slot, the length of the first time unit is N times the length of a time slot, where N is an integer greater than or equal to 2.

[0017] In some implementations of the second aspect, the processing unit is specifically used to: if the channel state is currently occupied, then after a second duration following the end of the first channel being occupied, execute a first backoff, wherein the duration of executing the first backoff is less than or equal to the first duration; wherein the backoff process includes the first backoff.

[0018] In some implementations of the second aspect, the second duration is determined based on the length of the first time unit.

[0019] In some implementations of the second aspect, the second duration is the sum of the product of the length of the first time unit and the number of arbitration frame gaps (AIFSN) and the length of the short frame gap.

[0020] In some implementations of the second aspect, the processing unit is further configured to: determine the length of the first time unit based on configuration information, wherein the configuration information configures the length of the first time unit to be greater than the length of a time slot, or the configuration information configures the length of the first time unit to be less than the length of a time slot.

[0021] It should be understood that for any details not fully described in the second aspect, please refer to the first aspect.

[0022] Thirdly, a communication device is provided, comprising: a memory for storing a program; and at least one processor for executing the computer program or instructions stored in the memory to perform the method provided in any of the foregoing aspects or their implementations.

[0023] In one implementation, the device is a first device.

[0024] In another implementation, the device is a chip, chip system, or circuit used in the first device.

[0025] Fourthly, a communication device is provided, comprising: at least one processor and a communication interface, wherein the at least one processor is configured to obtain a computer program or instructions stored in a memory via the communication interface to execute the method provided in any of the above aspects or their implementations. The communication interface may be implemented in hardware or software.

[0026] In one implementation, the device also includes a memory.

[0027] Fifthly, a processor is provided for executing the methods provided in the above aspects.

[0028] Unless otherwise specified, or if it does not contradict its actual function or internal logic in the relevant description, the transmission and acquisition / reception operations involved in the processor can be understood as processor output and reception, input and other operations, or as transmission and reception operations performed by radio frequency circuits and antennas. This application does not limit them in this regard.

[0029] In a sixth aspect, a computer-readable storage medium is provided that stores program code for execution by a device, the program code including methods for performing any of the foregoing aspects or their implementations.

[0030] In a seventh aspect, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the method provided in any of the foregoing aspects or their implementations.

[0031] Eighthly, a chip is provided, comprising a processor and a communication interface. The processor reads instructions stored in a memory through the communication interface and executes the methods provided in any of the above aspects or their implementations. The communication interface can be implemented in hardware or software.

[0032] Optionally, as one implementation, the chip also includes a memory that stores computer programs or instructions. The processor is used to execute the computer programs or instructions stored in the memory. When the computer programs or instructions are executed, the processor is used to perform the methods provided by any of the above aspects or their implementations.

[0033] When the method provided in this application is executed by a chip, this application does not limit the specific number of chips implementing the method. For example, it can be executed by one chip, or by two or more chips. Furthermore, when the number of chips implementing the method is two or more, the chip manufacturers are not limited; they can be from the same manufacturer or different manufacturers.

[0034] Ninthly, a computer program product is provided that, when run on a computer, causes the methods provided by any of the foregoing aspects or their implementations to be executed.

[0035] In a tenth aspect, a communication system is provided, including the first device described above.

[0036] It should be understood that the beneficial effects of aspects three through nine and any of their implementations can be referenced from aspect one and any of its implementations. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of one application scenario to which this application applies.

[0038] Figure 2 This is a schematic diagram of a communication system to which this application applies.

[0039] Figure 3 This is a schematic diagram illustrating another application scenario to which this application applies.

[0040] Figure 4 This is an example diagram illustrating the random backoff process among multiple access points (APs) based on the EDCA mechanism.

[0041] Figure 5 This is an example diagram illustrating the random backoff process between AP1 and AP2 based on the EDCA mechanism.

[0042] Figure 6 This is a schematic flowchart of the channel access method 600 provided in this application.

[0043] Figure 7 This is a schematic diagram of the retreat process provided in this application.

[0044] Figure 8 and Figure 9 A schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0045] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0046] The embodiments of this application can be applied to wireless local area networks (WLANs), such as those supporting IEEE 802.11 related standards, including 802.11a / b / g, 802.11n, 802.11ac, 802.11ax (i.e., Wi-Fi 6, also known as the high efficient (HE) standard), 802.11be (i.e., Wi-Fi 7, also known as the extremely high throughput (EHT) standard), 802.11bn (i.e., Wi-Fi 8, also known as the ultra high reliability (UHR) standard), or next-generation Wi-Fi 8 standards, as well as 802.11ad and 802.11ay standards. The embodiments of this application can also be applied to wireless local area network systems that support integrated millimeter wave (IMMW), wireless local area network systems that support ultra-wideband (UWB) such as the 802.15 series standards, sensing systems such as the 802.11bf series standards, or wireless positioning such as 802.11az. This application can also support standard protocols such as spark link and near link.

[0047] The various aspects described in this application can be extended to other networks employing various standards or protocols, such as high-performance radio local area networks (HIPERLANs), wireless wide area networks (WWANs), wireless personal area networks (WPANs), or other networks now known or developed in the future. Therefore, regardless of the coverage area and wireless access protocol used, the various aspects provided in this application can be applied to any suitable wireless network.

[0048] The technical solutions of this application embodiment can also be applied to various communication systems, such as: WLAN communication systems, Wi-Fi systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication systems, 5th generation (5G) systems or new radio (NR) systems, next-generation communication systems, Internet of Things (IoT) networks or vehicle-to-everything (V2X) networks, etc.

[0049] The technical solutions of this application embodiment can also be applied to various passive optical network (PON) systems, such as next-generation PON (NG-PON), NG-PON1, NG-PON2, gigabit-capable PON (GPON), 10 gigabit per second PON (XG-PON), 10-gigabit-capable symmetric passive optical network (XGS-PON), Ethernet PON (EPON), 10 gigabit per second EPON (10G-EPON), next-generation EPON (NG-EPON), wavelength-division multiplexing (WDM) PON, time-division wavelength-division multiplexing (TWDM) PON, and point-to-point (P2P) WDM. PON (P2P-WDM PON), Asynchronous Transfer Mode PON (APON), Broadband PON (BPON), and others, including 25 gigabit per second PON (25G-PON), 50 gigabit per second PON (50G-PON), 100 gigabit per second PON (100G-PON), 25 gigabit per second EPON (25G-EPON), 50 gigabit per second EPON (50G-EPON), 100 gigabit per second EPON (100G-EPON), and other rates such as GPON and EPON. It can also be used in optical networks such as optical transport networks (OTN).

[0050] The communication systems described above that are applicable to this application are merely illustrative examples, and the communication systems applicable to this application are not limited thereto.

[0051] Figure 1 This is a schematic diagram illustrating an application scenario to which this application's embodiments apply. For example... Figure 1 As shown, the communication method provided in this application is applicable to data communication between stations (STAs). A station can be an access point (AP) or a non-access point station (non-APSTA), referred to as an AP and a non-AP station, respectively. Specifically, the solution of this application is applicable to communication between an AP and one or more non-AP stations (e.g., communication between AP1 and non-AP STA1, non-AP STA2), communication between APs (e.g., communication between AP1 and AP2), and communication between non-AP STAs (e.g., data communication between non-APSTA2 and non-AP STA3). Unless otherwise specified in this application, a station (or STA) includes both non-APSTAs and APs; that is, a station (or STA) can be either a non-AP STA or an AP.

[0052] An Access Point (AP) can be a node that allows terminals (such as mobile phones) to access a wired (or wireless) network. It is primarily deployed in homes, buildings, and campuses, with a typical coverage radius of tens to hundreds of meters. Of course, it can also be deployed outdoors. An AP acts as a bridge connecting wired and wireless networks, its main function being to connect various wireless network clients together and then connect the wireless network to the Ethernet.

[0053] Specifically, an AP can be a terminal or network device with a Wi-Fi chip. This network device can be a server, router, switch, bridge, computer, mobile phone, relay station, vehicle-mounted equipment, wearable device, network device in a 5G network, network device in a 6G network, or network device in a public land mobile network (PLMN), etc., and this application embodiment is not limited to these. The AP can be a device that supports Wi-Fi standards. For example, the AP can also support one or more standards in the IEEE 802.11 series, such as 802.11be and 802.11be next generation.

[0054] Non-AP sites can be wireless communication chips, wireless sensors, or wireless communication terminals, and can also be referred to as users, user equipment (UE), access terminals, user units, user stations, mobile stations, mobile stations, remote stations, remote terminals, mobile devices, user terminals, terminals, wireless communication equipment, user agents, or user devices. Non-AP sites can be cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, IoT devices, wearable devices, terminal devices in 5G networks, terminal devices in future communication systems, or terminal devices in PLMNs, etc., and this application embodiment is not limited to these. Non-AP sites can be devices that support WLAN standards. For example, non-AP sites can support one or more standards in the IEEE 802.11 series, such as 802.11be and 802.11be next generation.

[0055] For example, non-AP sites can be mobile phones, tablets, set-top boxes, smart TVs, smart wearable devices, vehicle communication devices, computers, Internet of Things (IoT) nodes, sensors, smart home devices such as smart cameras, smart remote controls, smart water and electricity meters, and sensors in smart cities.

[0056] The aforementioned AP or non-AP sites may include transmitters, receivers, memory, processors, etc., wherein the transmitter and receiver are used for transmitting and receiving packet structures, respectively, the memory is used for storing signaling information and pre-agreed preset values, etc., and the processor is used for parsing signaling information and processing related data, etc.

[0057] Figure 2 This is a schematic diagram of a system architecture for fiber to the home or office (FTTH / O) applicable to embodiments of this application.

[0058] like Figure 2As shown, an optical line terminal (OLT) connects to upper-layer network-side devices (such as switches and routers) and lower-layer devices (such as optical distribution networks, ODNs). An ODN includes passive optical splitters for optical power distribution, a backbone fiber connecting the passive optical splitter and the OLT, and branch fibers connecting the passive optical splitter and ONUs. When transmitting downlink signals, the downlink signal sent by the OLT is transmitted to each ONT through the splitter, and the ONT selectively receives downlink data belonging to itself from the downlink signal. When transmitting uplink signals, the uplink signals sent by N ONTs are combined into a single optical signal by the splitter and transmitted to the OLT. An optical network unit (ONU) provides a user-side interface to the ODN and is connected to the ODN. If the ONU also provides user port functionality, such as an Ethernet user port or a plain old telephone service (POTS) user port, it is called an optical network termination (ONT).

[0059] Building upon FTTH / O, to address the issue of home Wi-Fi coverage, fiber optic cables can be extended further into residents' rooms. Optical terminal equipment providing Wi-Fi access is installed inside the rooms, thus reducing the distance between the user's device and the Wi-Fi access point and improving signal quality. This application scenario is called Fiber to the Room (FTTR).

[0060] Figure 3 This is a schematic diagram of the system architecture of FTTR applicable to embodiments of this application.

[0061] like Figure 3 As shown, in FTTH / O, the OLT is deployed in the central equipment room, while the ONT is deployed in homes or offices. The master device in the FTTR network acts as both the ONT in the FTTH network and the upstream device for the FTTR slave devices, managing them. The slave devices in FTTR can be deployed in various rooms of homes or offices to provide signal to user terminals. The slave devices possess the functions of an ONT and can also function as wireless access points (APs).

[0062] Multiple slave devices can be deployed in an FTTR system, each connected to the master device via an optical splitter. The master device can centrally manage and configure all slave devices. The master device can also be called a "master gateway," "master optical modem," or "master FTTR unit (MFU)," while slave devices can be called "slave gateways," "slave optical modems," or "slave FTTR units (SFU)," etc.

[0063] In the above application scenarios, each station can independently compete for the channel and transmit data after successfully seizing the channel. This could be an AP in a WLAN communication system, a non-AP STA, or a master or slave device in an FTTR. The following explanation uses an AP as an example. For instance, an AP can use an enhanced distributed channel access (EDCA) mechanism to back off and seize the channel, and transmit data after successfully seizing it. Once an AP seizes the channel, other APs can determine the busy / idle state of the channel based on channel monitoring, and back off and access the channel if it is idle.

[0064] The EDCA mechanism primarily uses a backoff and waiting method to grant high-priority packets priority in transmission and more bandwidth. The basic idea of ​​EDCA is that when an AP intends to send data, it needs to perform Clear Channel Access (CCA). If the channel is idle for a period of time (such as the Arbitration Inter-Frame Spacing (AIFS)), the AP can initiate a random backoff (or random backoff) process. If the channel is occupied (busy), the AP must wait for the channel to become idle, and after remaining idle for a period of time (such as AIFS), it will begin the random backoff process. After the random backoff process is complete, the AP can transmit data.

[0065] It should be understood that the AP in this application may refer to the MFU and SFU in an FTTR network, or to the AP in a WLAN communication system (see the description above for details), without limitation.

[0066] Figure 4 An example diagram is shown illustrating a random backoff process among multiple APs based on the EDCA mechanism.

[0067] like Figure 4As shown, initially, AP1 sends a data frame, while AP2, AP3, and AP4 all delay sending their data frames. After AP1 finishes sending its data frame (i.e., the channel becomes idle), AP2, AP3, and AP4 remain idle for a period of time (e.g., AIFS) before initiating a random backoff process. At time #1, AP3 completes the random backoff process first, sends a data frame, and AP2 and AP4 freeze the remaining backoff time, as shown... Figure 4 As shown in the shaded area. When AP3 sends a data frame, AP5 delays sending its own data frame. After AP3 finishes sending its data frame (i.e., the channel becomes idle), AP2, AP4, and AP5 remain idle for a period of time before initiating a random backoff process. At time #2, AP4 completes the random backoff process first, sends its data frame, and AP2 and AP5 freeze the remaining backoff time, as shown in the image. Figure 4 The shaded area is shown in the diagram. Similarly, at time #3, AP5 completes the random backoff process and sends a data frame. At time #4, AP2 completes the random backoff process and sends a data frame.

[0068] The following is a brief introduction to the method by which the AP determines the random backoff time required for rollback. For example, the random backoff time required by the AP is a random backoff value (or random backoff value) multiplied by the duration of a time slot. The random backoff value is randomly selected from a uniformly distributed window [0, CW]. The contention window (CW) has multiple values. It is initialized to its minimum value (CWmin) during the initial attempt. Each time a transmission fails (e.g., a collision occurs), a retransmission is required, and CW increases progressively until it reaches its maximum value (CWmax). When data is successfully transmitted, CW is reset to CWmin.

[0069] EDCA allows services of different access categories (ACs) to have different sets of EDCA parameters. Currently, the protocol defines the following ACs: Background Information Access Category (AC_background, AC_BK), Best Effort Access Category (AC_best effort, AC_BE), Voice Access Category (AC_voice, AC_VO), Video Access Category (AC_video, AC_VI), and Legacy Access Category. Different access categories can also represent different service types.

[0070] The EDCA parameter set includes a set of parameters for channel access corresponding to each AC. Parameters in the EDCA parameter set include CWmin, CWmax, AIFSN (which can be used to determine AIFS), and the transmission opportunity (TXOP) limit, i.e., the maximum number of transmission opportunities. Table 1 shows an example of the (default) EDCA parameter values ​​for a different AC.

[0071] Table 1

[0072] AC CWmin CWmax AIFSN TXOP limit AC_BK 31 1023 7 0 AC_BE 31 1023 3 0 AC_VI 15 31 2 3.008ms AC_VO 7 15 2 1.504ms legacy 15 1023 2 0

[0073] As can be seen from Table 1, different arbitration interframe spacing number (AIFSN) and CW settings will be used for different service types (such as voice, video, etc.). These settings can enable high-priority services to obtain the channel more quickly, thereby reducing latency and improving service quality.

[0074] AIFSN is used to determine the backoff time after the channel becomes idle, i.e., AIFS. AIFS is calculated as AIFS[AC] = aSIFSTime + AIFSN[AC] * aSlotTime. For example, for a service with access level AC_BE, its EDCA parameter set is {CWmin = 31, CWmax = 1023, AIFSN = 3}. Therefore, during the EDCA backoff process, AIFS is aSIFSTime + 3 * aSlotTime. That is, when the channel returns to idle, the AP must wait aSIFSTime + 3 * aSlotTime before it can backoff. Here, aSlotTime represents the length of a time slot, typically 9µs; aSIFSTime represents the length of the short interframe space (SIFS), typically 16µs.

[0075] As network scale increases, the synchronization accuracy between access points (APs) may become limited. Using the current EDCA mechanism to compete for access channels may increase the probability of air interface collisions (i.e., neither AP can detect the other's data frame transmission in time, causing data packets to interfere with each other and preventing timely data transmission) due to the reduced synchronization accuracy between APs. Figure 5The diagram illustrates the expected contention for channel access between AP1 and AP2. At time #1, the channel is busy, and AP1 and AP2 can delay accessing the channel. At the end of the channel occupancy period, AP1 and AP2 wait for the same AIFS and begin backoff at time #2. Depending on the random backoff value selected by AP1 and AP2, for example, if the difference is 1, then at time #3, AP1 transmits Physical Layer Protocol Data Unit (PPDU) 1, which carries the data to be sent by AP1. AP2's channel sniffing indicates that the channel is busy, and AP2 performs EDCA backoff until the channel becomes idle, at which point AP2 initiates transmission. The above process may encounter the problem of limited synchronization accuracy between AP1 and AP2. For example, if the synchronization accuracy error between AP1 and AP2 is one time slot, a data transmission conflict may occur between AP1 and AP2. For instance, according to the backoff time information of AP1, AP1 is expected to transmit data in the i-th time slot of a system frame, and AP2 is expected to transmit data in the (i+1)-th time slot of a system frame. If the synchronization accuracy error between AP1 and AP2 is one time slot, AP1 may transmit a data frame in the (i+1)-th time slot, resulting in a data transmission conflict between the two APs.

[0076] In view of this, this application proposes a random access method and communication device, which can reduce the probability of air interface collision when the AP sends data frames and reduce data transmission latency.

[0077] To facilitate understanding of the embodiments of this application, the following points are provided.

[0078] First, the terms "first," "second," and various numerical designations (e.g., "#1," "#2," etc.) shown in this application are for descriptive convenience and to distinguish objects, and are not intended to limit the scope of the embodiments of this application. For example, they are used to distinguish different devices, etc., and are not used to describe a specific order or sequence. It should be understood that such described objects can be interchanged where appropriate to describe solutions other than those in the embodiments of this application.

[0079] Second, in the embodiments of this application, the terms "of", "corresponding (relevant)", "corresponding" and "associate" can sometimes be used interchangeably. It should be noted that when their differences are not emphasized, their intended meanings are consistent.

[0080] It should be understood that the embodiments shown below illustrate the method using a first device as the execution subject, but this application does not limit the execution subject. Any program capable of running the code of the method provided in the embodiments of this application can communicate according to the method provided in the embodiments of this application. The execution subject of the method provided in the embodiments of this application can be the first device, or a functional module within the first device capable of calling and executing a program. For example, Figure 6 The first device in the context can also be a chip, chip system, or processor that supports the methods that the first device can implement, or it can be a logic module or software that can implement all or part of the functions of the first device.

[0081] Figure 6 This is a schematic flowchart of a communication method 600 provided in this application. Figure 6 As shown, the method 600 includes the following steps.

[0082] S610, the first device determines the retreat time information based on the length of the first time unit.

[0083] The first device can be an AP or a non-AP STA; the first device can also be a device in the FTTR, such as the master device in the FTTR or the slave device in the FTTR.

[0084] This backoff time information can indicate the duration of the backoff (denoted as the first duration). The first duration is related to the number of remaining backoff time slots and the length of the first time unit. For example, the first duration can be the product of the number of remaining backoff time slots and the length of the first time unit.

[0085] The remaining backoff time slots can be replaced by a random backoff value or the value of a backoff counter (or backoff countdown). It should be understood that if the first device does not perform backoff, the remaining backoff time slots are the initially determined backoff time slots. This initially determined backoff time slot number can be selected from the contention window; for example, the initially determined backoff time slot number can be randomly selected from [0, CWmin].

[0086] The length of the first time unit is greater than the length of a time slot. This application does not specify the exact value of the length of the first time unit.

[0087] As an example, the length of this first time unit is N times the length of a time slot, where N is an integer greater than or equal to 2. For instance, if the length of a time slot is 9 µs, the value of this first time unit is 18 µs.

[0088] As another example, the length of the first time unit is an integer multiple of the synchronization error between APs. For example, if the synchronization error between APs is 10µs, the first time unit is an integer multiple of 10µs.

[0089] It is understandable that when there are multiple access points (APs) in a network, the synchronization error can be taken as the average of the synchronization errors between APs. The synchronization accuracy error between APs can be determined based on measurement, for example, by measuring the time stamped messages sent by the APs; please refer to existing relevant descriptions for details.

[0090] As another example, the length of the first time unit is a specific time length, for example, a time length greater than the length of a time slot.

[0091] Optionally, before determining the retreat time information, the first device determines the length of the first time unit.

[0092] For example, the first device determines the length of the first time unit based on configuration information. This configuration information configures the length of the first time unit to be greater than the length of a time slot. For instance, the configuration information configures the length of the first time unit to be N times the length of a time slot, and the configuration information can configure the value of N. As another example, the configuration information can configure the first time unit to be a time unit of a specific length, which is greater than the length of a time slot.

[0093] The above configuration information can be pre-configured in the first device, or the first device can receive the configuration information from the second device; there is no limitation in either case. For example, the second device can be a management device of the first device. For instance, if the first device is an SFU in an FTTR, the second device can be an MFU or other management device; there is no limitation in either case.

[0094] S620, the first device performs a backoff process based on the channel state of the first channel and the backoff time information.

[0095] The first channel is used by the first device to transmit data after the backoff operation has ended.

[0096] This application does not specifically limit the first channel. For example, the first channel may be the main channel, such as the main 20MHz channel. The operating frequency band of the first channel may be 2.4GHz, 5GHz, 6GHz, or 60GHz, etc.

[0097] For example, if the channel state of the first channel is occupied (busy), the first device waits for a second duration after the first channel occupancy ends before performing a first backoff. After the first backoff ends, the random backoff value is reduced by a first value, which is greater than or equal to 0 and less than or equal to the initial value of the random backoff value. That is, the first value is related to the ratio of the third duration to the length of the first time unit, where the third duration is the time between the start of the first backoff and the moment the first channel is occupied again.

[0098] For example, such as Figure 7 As shown, the first device starts idle detection of the first channel from time #1. If it detects that the state of channel #1 (an example of the first channel) is busy, the first device can start from the end time when channel #1 is occupied (i.e., time #2), wait for AIFSN (an example of the second duration) and then start executing the first backoff (the backoff process corresponding to the contention window) after the AIFSN (an example of the second duration) is completed (i.e., time #3). According to the contention access situation of other devices in the network for the first channel, after executing the first backoff, channel #1 is occupied. The first device freezes the remaining backoff time and waits for the second duration after the end time when channel #1 is occupied. After the second duration, it continues to execute backoff (e.g., the backoff time is T1). The first device sends a data frame or freezes the remaining backoff time, waits for the first channel to become idle again, and continues to execute backoff after a period of time. The backoff is completed at time #5, and the first device sends the data frame.

[0099] If the first channel state is currently idle, then after waiting for a second period of time, the first backoff is executed; after the execution of the first backoff is completed, the random backoff value is reduced by a first value, and the first value and the process of executing the first backoff are described above.

[0100] It should be understood that the backoff process performed above based on the channel state and backoff time information of the first information is merely an example, and this application does not limit the specific backoff process. For example, the backoff process could be a backoff process in a high-priority channel access process.

[0101] Optionally, the second duration is determined based on the length of the first time unit. That is, the duration for which the first device waits to back off (e.g., AIFS) from the end of the first channel being occupied can be determined based on the first time unit.

[0102] For example, AIFS can be calculated as AIFS[AC] = aSIFSTime + AIFSN[AC] * T0. T0 represents the length of the first time unit. For a service with access level AC_BE, whose EDCA parameter set is {CWmin = 31, CWmax = 1023, AIFSN = 3}, then AIFS is aSIFSTime + 3 * T0. That is, when the channel returns to idle, the AP must wait for aSIFSTime + 3 * T0 before it can perform the backoff process. Here, aSIFSTime represents the length of the short interframe space (SIFS), which is usually 16µs.

[0103] Based on the above scheme, when the synchronization accuracy between devices is limited, the probability of air interface collision when the devices send data frames can be reduced by adjusting the length of the first time unit, thereby reducing data transmission latency.

[0104] Alternatively, in another embodiment, the length of the first time unit can be less than the length of a time slot. For example, when the synchronization accuracy of devices in the network is high, and / or the detection accuracy of devices in the network is high, the length of the first time unit can be configured to be less than the length of a time slot.

[0105] For example, in this embodiment, the first device determines backoff time information based on the first time unit, and performs backoff according to the backoff time information and the channel state of the first channel. The specific steps described above can be found in the description of method 500, and will not be repeated here.

[0106] The above, combined with Figures 1 to 7 The methods provided in the embodiments of this application are described in detail below. Figure 8 and Figure 9 The apparatus provided in the embodiments of this application is described in detail. It should be understood that the description of the apparatus embodiments corresponds to the description of the method embodiments. Therefore, for content not described in detail, please refer to the method embodiments above. For the sake of brevity, it will not be repeated here.

[0107] It is understood that, in order to achieve the functions in the above embodiments, the base station and terminal include hardware structures and / or software modules corresponding to perform each function. Those skilled in the art should readily recognize that, based on the units and method steps described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0108] Figure 8 and Figure 9This is a schematic diagram of the structure of a communication device provided in the embodiments of this application. These communication devices can be used to implement the functions of a terminal or base station in the above method embodiments, and therefore can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be a first device, or it can be a module (such as a chip) applied to a first device, a second device, or a third device.

[0109] like Figure 8 As shown, the communication device 2000 includes a processing unit 2010. Optionally, the communication device 2000 also includes a transceiver unit 2020. The communication device 2000 is used to implement the above-mentioned... Figure 6 The method embodiment shown illustrates the function of the first device.

[0110] When the communication device 2000 is used to achieve Figure 6 In the method embodiment shown, the function of the first device is as follows: the processing unit 2010 is used to: determine backoff time information based on the length of the first time unit, the backoff time information indicating the first device to perform a first backoff duration, the length of the first time unit being greater than or less than the length of a time slot; the processing unit 2010 is also used to: perform a backoff process according to the channel state of the first channel and the backoff time information, wherein the first channel is used to transmit the data of the first device after the backoff ends.

[0111] For a detailed description of the functions performed by the processing unit 2010 and the transceiver unit 2020, please refer to [reference needed]. Figure 6 The relevant description is shown in method 600.

[0112] like Figure 9 As shown, the communication device 3000 includes a processor 3010 and an interface circuit 3020. The processor 3010 and the interface circuit 3020 are coupled to each other. It is understood that the interface circuit 3020 can be a transceiver or an input / output interface. Optionally, the communication device 3000 may also include a memory 3030 for storing instructions executed by the processor 3010, or storing input data required by the processor 3010 to execute instructions, or storing data generated after the processor 3010 executes instructions. Sometimes, the interface circuit 3020 can also be understood as part of the processor 3010, in which case the communication device 3000 includes the processor 3010.

[0113] When the communication device 3000 is used to achieve Figure 6 In the method shown, the processor 3010 is used to implement the functions of the processing unit 2010, and the interface circuit 3020 is used to implement the functions of the transceiver unit 2020.

[0114] When the aforementioned communication device is a chip applied to the first device, the chip implements the functions of the first device in the above method embodiments. The chip receiving information from other devices can be understood as the information being first received by other modules (such as an RF module or antenna) in the first device, and then sent to the chip by these modules. The chip sending information to other devices can be understood as the information being first sent to other modules (such as an RF module or antenna) in the first device, and then sent to the other devices by these modules.

[0115] It is understood that the processor in the embodiments of this application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor may be a microprocessor or any conventional processor.

[0116] The method steps in the embodiments of this application can be implemented in hardware or in software instructions executable by a processor. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. The storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a base station or terminal. The processor and storage medium can also exist as discrete components in a base station or terminal.

[0117] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0118] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions between different embodiments are consistent and can be referenced by each other. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0119] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. In the textual description of this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. "Including at least one of A, B, and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B, and C.

[0120] In this application, "predefined" can be achieved by pre-storing the corresponding code, table or other means that can be used to indicate relevant information in the device, and this application does not limit the specific implementation method.

[0121] It should be understood that in the various embodiments of this application, the terms "first," "second," and various numerical designations are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above processes does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

[0122] Those skilled in the art will recognize that the units and algorithm steps of the various examples 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 implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0123] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0124] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0125] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0126] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0127] If the aforementioned functions are implemented as software functional units 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 this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0128] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for channel access, characterized in that, Applied to a first device, the method includes: The backoff time information is determined based on the length of the first time unit, and the backoff time information indicates the first duration for which the first device performs backoff, wherein the length of the first time unit is greater than the length of a time slot; The backoff process is performed based on the channel state of the first channel and the backoff time information, wherein the first channel is used to transmit data of the first device after the backoff ends.

2. The method according to claim 1, characterized in that, The length of the first time unit is N times the length of a time slot, where N is an integer greater than or equal to 2.

3. The method according to claim 1 or 2, characterized in that, The backoff process based on the channel state of the first channel and the backoff time information includes: If the channel state is currently occupied, then after a second duration following the end of the first channel being occupied, a first backoff is executed, wherein the duration of the first backoff is less than or equal to the first duration. The retreat process includes the first retreat.

4. The method according to claim 3, characterized in that, The second duration is determined based on the length of the first time unit.

5. The method according to claim 4, characterized in that, The second duration is the sum of the product of the length of the first time unit and the number of arbitration frame gaps (AIFSN) and the length of the short frame gap.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: The length of the first time unit is determined based on the configuration information, and the configuration information configures the length of the first time unit.

7. A communication device, characterized in that, The device processing unit is configured to: The retreat time information is determined based on the length of the first time unit, and the retreat time information indicates the first duration for which the device performs retreat, wherein the length of the first time unit is greater than the length of a time slot; The backoff process is performed based on the channel state of the first channel and the backoff time information, wherein the first channel is used to transmit data of the device after the backoff ends.

8. The apparatus according to claim 7, characterized in that, The length of the first time unit is N times the length of a time slot, where N is an integer greater than or equal to 2.

9. The apparatus according to claim 7 or 8, characterized in that, The processing unit is specifically used for: If the channel state is currently occupied, then after a second duration following the end of the first channel being occupied, a first backoff is executed, wherein the duration of the first backoff is less than or equal to the first duration. The retreat process includes the first retreat.

10. The apparatus according to claim 9, characterized in that, The second duration is determined based on the length of the first time unit.

11. The apparatus according to claim 10, characterized in that, The second duration is the sum of the product of the length of the first time unit and the number of arbitration frame gaps (AIFSN) and the length of the short frame gap.

12. The apparatus according to any one of claims 7 to 11, characterized in that, The processing unit is also used for: The length of the first time unit is determined based on the configuration information, and the configuration information configures the length of the first time unit.

13. A communication device, characterized in that, include: Units for performing the methods described in any one of claims 1 to 6.

14. A communication device, characterized in that, include: A transceiver and a processor, the transceiver being configured to receive a signal and transmit the signal to the processor or another communication device other than the communication device, the processor being configured to perform the method as described in any one of claims 1 to 6.

15. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions, which, when executed by a communication device, implement the method as described in any one of claims 1 to 6.

16. A computer program product, characterized in that, Includes a computer program that, when run, implements the method as described in any one of claims 1 to 6.

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