Channel access method and related device

Abstract

An embodiment of the present application discloses a channel access method and a related device. The method includes: when a communication device transmits a frame but does not receive a corresponding response frame, increasing a backoff exponent and performing backoff; performing CCA after the backoff is completed; and performing transmission if the CCA result is idle or re-performing backoff if the CCA result is busy. According to the embodiment of the present application, collisions or contentions can be reduced in a scenario where a hidden terminal exists, and channel access performance can be improved. The present application is applicable to UWB-based WAPN systems, sensing systems, etc., including 802.15 series protocols such as the 802.15.4ab protocol or next-generation UWB protocols of the 802.15.4ab protocol, and may further be applicable to wireless local area network systems based on 802.11 series protocols such as 802.11be or next-generation protocols of 802.11be, such as Wi-Fi 8.

Description

[Technical Field]

[0001] The present application relates to the field of wireless communication technologies, and in particular to a channel access method and related apparatus. [Background technology]

[0002] This application claims priority to Chinese Patent Application No. 202211378676.5, entitled "CHANNEL ACCESS METHOD AND RELATED APPARATUS," filed with the State Intellectual Property Office of the People's Republic of China on November 4, 2022, the entire contents of which are incorporated herein by reference.

[0003] An important technology for unlicensed spectrum is channel access. The goal of channel access is to use the spectrum efficiently while ensuring fairness among users, in other words, to improve spectral efficiency as much as possible. Carrier sense multiple access (CSMA) is a common channel access technique. Before channel access is performed, energy detection (or carrier sensing) is performed to determine if the channel is busy or idle, and transmission is only allowed when the channel is idle. To further reduce collisions, a random backoff mechanism is used in CSMA. Specifically, a random wait period is used.

[0004] In the existing CSMA, collision (or contention) avoidance depends on the result of energy detection (or carrier sense). Therefore, if the result of energy detection (or carrier sense) indicates that the channel is busy, the backoff period is extended, or if the result of energy detection (or carrier sense) indicates that the channel is idle, a radio frame is transmitted. However, in a scenario where a hidden terminal exists, collision (or contention) may occur even if the result of energy detection (or carrier sense) indicates that the channel is idle. Therefore, conventional channel access techniques have the problems of frequent collisions and performance degradation in a scenario where a hidden terminal exists. Summary of the Invention

[0005] SUMMARY OF THE INVENTION The embodiments of the present application provide a channel access method and related apparatus for reducing collisions or contentions and improving channel access performance in scenarios where hidden terminals exist.

[0006] In the following, the present application will be described from different aspects, and it should be understood that the following implementations and beneficial effects of different aspects will be referred to each other.

[0007] According to a first aspect, the present application provides a channel access method, which is applied to a scenario in which a hidden terminal exists, and includes: a communication device transmits a first radio frame, and detects whether a response frame to the first radio frame is received within a preset time after the transmission. If a response frame for the first radio frame is not received, the communication device increases the value of a first backoff exponent and performs backoff based on the increased value of the first backoff exponent; the communication device performs clear channel allocation after the backoff is completed, and if the result of the clear channel allocation is that the channel is idle, the communication device transmits the first radio frame, or if the result of the clear channel allocation is that the channel is busy, the communication device increases the value of a second backoff exponent and performs backoff again; and / or if a response frame for the first radio frame is received, the communication device sets the first backoff exponent to the minimum value of the first backoff exponent and performs backoff based on the minimum value of the second backoff exponent; the communication device performs clear channel allocation after the backoff is completed, and if the result of the clear channel allocation is that the channel is idle, the communication device transmits the second radio frame, or if the result of the clear channel allocation is that the channel is busy, the communication device increases the value of the second backoff exponent and performs backoff again.

[0008] The first backoff exponent may be used to reflect backoff caused by collisions, and the second backoff exponent may be used to reflect backoff caused when a clear channel assignment (CCA) results in the channel being busy.

[0009] It may be understood that there may be multiple backoff methods, for example, linear backoff or exponential backoff, and the particular backoff method is not limited in this application.

[0010] In the present application, when a corresponding response is not received after a radio frame is sent, i.e., when a collision / contention occurs, the value of the first backoff exponent is increased to increase the backoff window, so that backoff is performed to reduce collisions or contentions in a scenario where a hidden terminal exists and to improve channel access performance.

[0011] Regarding the first aspect, in a possible implementation, after the communication device increases the value of the first backoff exponent, the method further includes: if the increased value of the first backoff exponent is less than or equal to the maximum value of the first backoff exponent, the communication device performs backoff based on the increased value of the first backoff exponent.

[0012] Optionally, if the increased value of the first back-off exponent is greater than the maximum value of the first back-off exponent, the communication device implements back-off based on the maximum value of the first back-off exponent.

[0013] Regarding the first aspect, in a possible implementation, implementing the backoff based on the increased value of the first backoff exponent includes assigning the increased value of the first backoff exponent to a second backoff exponent, and then implementing the backoff based on the value of the second backoff exponent. In other words, the value of the first backoff exponent affects the value of the second backoff exponent.

[0014] In the present application, the value of the first backoff exponent is assigned to the second backoff exponent, and the backoff is performed based on the second backoff exponent to ensure the continuity of the backoff window, which can prevent the situation where the backoff window increases due to a transmission collision but decreases after CCA is performed.

[0015] Regarding the first aspect, in a possible implementation, the first backoff exponent may be the same as the second backoff exponent. When the first backoff exponent is the same as the second backoff exponent, no new backoff exponent is introduced in this application, so the implementation is simple, the number of parameters is small, and the complexity is low.

[0016] Regarding the first aspect, in a possible implementation, after the communication device transmits the first radio frame, the method further includes: when the communication device receives a response frame for the first radio frame after transmitting the first radio frame, the communication device sets a value of a collision number counter to 0, or when the communication device does not receive a response frame for the first radio frame after transmitting the first radio frame, the communication device increases the value of the collision number counter.

[0017] Optionally, the communication device resets the value of the collision counter to 0 when the incremented value of the collision counter is greater than a preset threshold.

[0018] In this application, a new counter (collision count counter) is used to record the number of backoffs caused by collisions, which makes the design more flexible and may not affect the records of the original backoff count counter.

[0019] Optionally, the collision counter is a backoff counter, which is used to record the number of backoffs that occur when the CCA result is that the channel is busy.

[0020] In this application, a backoff count counter is used to record all backoff counts so that the channel access delay can be reduced once in scenarios with many collisions and so that the next channel access can be entered more quickly.

[0021] Regarding the first aspect, in a possible implementation, the communication device increasing the value of the second backoff exponent and re-performing the backoff includes: the communication device increasing the value of the second backoff exponent, and if the increased value of the second backoff exponent is less than or equal to a maximum value of the second backoff exponent, the communication device re-performs the backoff based on the increased value of the second backoff exponent; or if the increased value of the second backoff exponent is greater than the maximum value of the second backoff exponent, the communication device re-performs the backoff based on the maximum value of the second backoff exponent.

[0022] Regarding the first aspect, in a possible implementation, at least one of the minimum value of the first back-off exponent, the minimum value of the second back-off exponent, the maximum value of the first back-off exponent, and the maximum value of the second back-off exponent is predefined or preset.

[0023] Regarding the first aspect, in a possible implementation, before the communication device sends out the first radio frame, the method further includes: the communication device receives configuration parameters from the central control node, the configuration parameters including one or more of the following: a minimum first back-off exponent, a minimum second back-off exponent, a maximum first back-off exponent, or a maximum second back-off exponent.

[0024] Optionally, the configuration parameters are carried in a wireless broadcast frame.

[0025] According to a second aspect, the present application provides a communication device including a transceiver unit and a processing unit, wherein the transceiver unit is configured to transmit a first radio frame, and the processing unit is configured to increase a value of a first backoff exponent when a response frame for the first radio frame is not received after the first radio frame is transmitted, perform backoff based on the increased value of the first backoff exponent, perform clear channel assignment after the backoff is completed, increase a value of a second backoff exponent and perform backoff again when the result of the clear channel assignment is that the channel is busy, and control the transceiver unit to transmit the first radio frame when the result of the clear channel assignment is that the channel is idle; and / or The processing unit is further configured to: when a response frame for the first radio frame is received after the first radio frame is sent, set the first backoff exponent to the minimum value of the first backoff exponent; perform backoff based on the minimum value of the second backoff exponent; perform clear channel allocation after the backoff is completed; when the result of the clear channel allocation is that the channel is busy, increase the value of the second backoff exponent and perform backoff again; and when the result of the clear channel allocation is that the channel is idle, control the transceiver unit to send the second radio frame.

[0026] Regarding the second aspect, in a possible implementation, the processing unit is further configured to perform backoff based on an increased value of the first backoff exponent when the increased value of the first backoff exponent is less than or equal to a maximum value of the first backoff exponent.

[0027] Regarding the second aspect, in a possible implementation, the processing unit is further configured to perform backoff based on a maximum value of the first backoff exponent when the increased value of the first backoff exponent is greater than the maximum value of the first backoff exponent.

[0028] Regarding the second aspect, in a possible implementation, the processing unit is particularly configured to perform the backoff based on a value of a second backoff exponent, the value of the second backoff exponent being an increased value of the first backoff exponent.

[0029] Regarding the second aspect, in a possible implementation, the first back-off exponent is the same as the second back-off exponent.

[0030] Regarding the second aspect, in a possible implementation, the processing unit is further configured to set a value of the collision counter to 0 when a response frame for the first radio frame is received after the first radio frame is sent, and / or to increment the value of the collision counter when no response frame for the first radio frame is received after the first radio frame is sent.

[0031] Optionally, the collision counter is a backoff counter, which is used to record the number of backoffs that occur when the CCA result is that the channel is busy.

[0032] Optionally, the processing unit is further configured to reset a value of the collision number counter to 0 when the incremented value of the collision number counter is greater than a preset threshold value.

[0033] Regarding the second aspect, in a possible implementation, the processing unit is particularly configured to increase the value of the second back-off exponent and re-implement the back-off based on the increased value of the second back-off exponent when the increased value of the second back-off exponent is less than or equal to the maximum value of the second back-off exponent, or to re-implement the back-off based on the maximum value of the second back-off exponent when the increased value of the second back-off exponent is greater than the maximum value of the second back-off exponent.

[0034] Regarding the second aspect, in a possible implementation, at least one of the minimum value of the first back-off exponent, the minimum value of the second back-off exponent, the maximum value of the first back-off exponent, and the maximum value of the second back-off exponent is predefined or preset.

[0035] Regarding the second aspect, in a possible implementation, the transceiver unit is further configured to receive configuration parameters from the central control node, the configuration parameters including one or more of the following: a minimum value of the first back-off exponent, a minimum value of the second back-off exponent, a maximum value of the first back-off exponent, or a maximum value of the second back-off exponent.

[0036] Optionally, the configuration parameters are carried in a wireless broadcast frame.

[0037] According to a third aspect, the present application provides a communications device. The communications device includes a processor configured to perform a method according to the first aspect or any one of the possible implementations of the first aspect. Alternatively, the processor is configured to execute a program stored in a memory. When the program is executed, the method according to the first aspect or any one of the possible implementations of the first aspect is performed.

[0038] Regarding the third aspect, in a possible implementation the memory is located external to the communication device.

[0039] Regarding the third aspect, in a possible implementation, the memory is located within the communication device.

[0040] In embodiments of the present application, the processor and the memory may alternatively be integrated into one component, in other words, the processor and the memory may alternatively be integrated together.

[0041] Regarding the third aspect, in a possible implementation, the communication device further includes a transceiver, the transceiver configured to receive the response frame or send the radio frame.

[0042] According to a fourth aspect, the present application provides a communications device, the communications device including a logic circuit and an interface, the logic circuit coupled to the interface, the interface configured to output a first radio frame, the logic circuit configured to: increase a value of a first backoff exponent when a response frame for the first radio frame is not received after the first radio frame is sent, perform backoff based on the increased value of the first backoff exponent, perform clear channel assignment after the backoff is completed, increase a value of a second backoff exponent and perform backoff again when the result of the clear channel assignment is that the channel is busy, and control the interface to output the first radio frame when the result of the clear channel assignment is that the channel is idle; and / or The logic circuit is further configured to: when a response frame for the first radio frame is received after the first radio frame is sent, set the first backoff exponent to the minimum value of the first backoff exponent; perform backoff based on the minimum value of the second backoff exponent; perform clear channel allocation after the backoff is completed; when the result of the clear channel allocation is that the channel is busy, increase the value of the second backoff exponent and perform backoff again; and when the result of the clear channel allocation is that the channel is idle, control the interface to output the second radio frame.

[0043] According to a fifth aspect, the present application provides a computer-readable storage medium configured to store a computer program, which, when run on a computer, performs a method according to the first aspect or any one of the possible implementations of the first aspect.

[0044] According to a sixth aspect, the present application provides a computer program product, the computer program product comprising a computer program or computer code, which, when run on a computer, performs the method according to the first aspect or any one of the possible implementations of the first aspect.

[0045] According to a seventh aspect, the present application provides a computer program which, when run on a computer, performs the method according to the first aspect or any one of the possible implementations of the first aspect.

[0046] The technical effects achieved in the above aspects are referred to each other or to the beneficial effects in the following method embodiments, and the details are not described herein. [Brief explanation of the drawings]

[0047] [Figure 1] 1 is a structural diagram of a wireless communication system according to an embodiment of the present application; [Figure 2] FIG. 2 is another structural diagram of a wireless communication system according to an embodiment of the present application; [Figure 3] 2 is a schematic flowchart of a channel access method according to an embodiment of the present application; [Figure 4] FIG. 1 is a diagram of a scenario in which a hidden terminal is present, according to an embodiment of the present application; [Figure 5] 4 is another schematic flowchart of a channel access method according to an embodiment of the present application; [Figure 6A] FIG. 1 is a diagram of a channel access procedure according to an embodiment of the present application. [Figure 6B] FIG. 1 is a diagram of a channel access procedure according to an embodiment of the present application. [Figure 7A] FIG. 10 is another diagram of a channel access procedure according to an embodiment of the present application. [Figure 7B] FIG. 10 is another diagram of a channel access procedure according to an embodiment of the present application. [Figure 8A] FIG. 10 is yet another diagram of a channel access procedure according to an embodiment of the present application. [Figure 8B] FIG. 10 is yet another diagram of a channel access procedure according to an embodiment of the present application. [Figure 9] 10A-10C are diagrams of simulations of beneficial effects according to embodiments of the present application. [Figure 10] 1 is a structural diagram of a communication device according to an embodiment of the present application; [Figure 11] 1 is a structural diagram of a communication device 1000 according to an embodiment of the present application. [Figure 12] FIG. 2 is another structural diagram of a communication device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0048] DETAILED DESCRIPTION OF THE INVENTION In the following, the technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings of the embodiments of the present application.

[0049] In the description of this application, unless otherwise specified, " / " means "or." For example, A / B may refer to A or B. The term "and / or" herein describes only the associative relationship between related objects and indicates that there are three possible relationships. For example, A and / or B may refer to the following three cases: only A is present, both A and B are present, and only B is present. Additionally, "at least one" means one or more, and "plurality" means two or more. At least one of the following items (pieces) or similar expressions refers to any combination of these items, including any combination of a single item (piece) or multiple items (pieces). For example, at least one of a, b, or c refers to a, b, c, a and b, a and c, b and c, or a, b, and c. In this specification, a, b, and c may be singular or plural.

[0050] In this application, the terms "first," "second," and the like distinguish different objects but do not indicate a particular order of objects. Additionally, the terms "comprise," "have," and any other variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include additional steps or units that are not listed, or may optionally include other steps or units that are inherent to the process, method, product, or device.

[0051] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present application. Phrases appearing in various places in this specification do not necessarily refer to the same embodiment, nor are they exclusive, unrelated, or optional embodiments of another embodiment. It may be explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0052] In this application, words such as "for example" or "such as" indicate an example, analogy, or illustration. Any embodiment or design manner described in this application using "an example," "in an example," or "for example" is not to be described as preferred or having more advantages over another embodiment or design manner. Strictly speaking, use of the terms "for example," "in an example," "for example," etc. is intended to present the relevant concept in a concrete manner.

[0053] It should be understood that in this application, "when" and "in the case of" mean that the device performs the corresponding processing in an objective situation, and do not limit the time. This term does not mean that the device is required to have a determining action during implementation, nor does it imply any other limitation.

[0054] In this application, elements referred to in the singular are intended to denote one or more and not only one, unless otherwise specified.

[0055] Additionally, the terms "system" and "network" may be used interchangeably herein.

[0056] In the embodiments of the present application, it should be understood that determining B based on A does not mean that B is determined based only on A, but that B may alternatively be determined based on A and / or other information.

[0057] The technical solutions provided in this application are applicable to various networks in unlicensed spectrum. Examples are not listed one by one in this specification. For example, the technical solutions provided in this application are applicable to wireless personal area networks (WPANs) based on ultra-wideband (UWB) technology. For example, the methods provided in this application are applicable to future generation UWB WPAN standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.15 series protocols, 802.15.4ab protocols, etc. For example, the technical solutions provided in this application are applicable to future generation UWB WPAN standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.15 series protocols, 802.15.4ab protocols, etc. For example, the technical solutions provided in this application are applicable to wireless local area networks (WLANs) based on 802.11 series protocols. For another example, the technical solutions provided in this application are further applicable to wireless local area networks (WLANs) based on 802.11 series protocols. For example, the methods provided in this application are applicable to 802.11ax, 802.11be, or their next generation, such as Wi-Fi 8 (also called ultra high reliability (UHR), or ultra high reliability and throughput (UHRT)). Examples are not listed one by one herein.

[0058] It should be understood that the network architecture described in the embodiments of the present application is intended to more clearly explain the technical solutions of the embodiments of the present application, but does not limit the technical solutions provided in the embodiments of the present application. Those skilled in the art will recognize that as network architectures evolve, the technical solutions provided in the embodiments of the present application can also be applied to similar technical problems.

[0059] In the embodiments of the present application, a UWB communication scenario in a wireless personal area network is used as an example to describe some scenarios. It should be understood that the solutions in the embodiments of the present application may also be applied to other wireless communication networks, and the corresponding names may also be replaced with the names of the corresponding functions of other wireless communication networks.

[0060] UWB technology is a new wireless communication technology. In UWB technology, data is transmitted using non-sinusoidal narrowband pulses at the nanosecond level. Modulation is performed on impulses with very steep rise and fall times. Therefore, UWB technology occupies a wide spectral range, resulting in signals with gigahertz (GHz)-scale bandwidths. The bandwidth used by UWB typically exceeds 1 GHz. UWB systems can transmit impulse sequences immediately without the need to generate a sinusoidal carrier signal. Therefore, UWB systems have a wide spectrum and low average power. UWB wireless communication systems have advantages such as strong multipath resolution, low power consumption, and high privacy. This facilitates coexistence with other systems, thereby improving spectrum utilization and system capacity. In addition, for short-range communication applications, the transmission power of a UWB transmitter can typically be less than 1 mW (milliwatt). Theoretically, interference generated by UWB signals is equivalent to white noise. This facilitates good coexistence between ultra-wideband communication and existing narrowband communication. Therefore, UWB systems and narrowband (NB) communication systems can operate simultaneously without interfering with each other.

[0061] The methods provided herein may be implemented by a communication device of a wireless communication system. In the communication device, a device or chip for implementing the functions of a UWB system may be referred to as a UWB module, and a device or chip for implementing the functions of a narrowband communication system may be referred to as a narrowband communication module. The UWB module and the narrowband communication module may be separate devices or chips. Of course, the UWB module and the narrowband communication module may alternatively be integrated into one device or chip. The implementation of the UWB module and the narrowband communication module in the communication device is not limited to the embodiments of the present application. The communication device of the present application includes a UWB module and / or a narrowband communication module.

[0062] In this application, narrowband may be understood relative to UWB. Any communication system operating at a bandwidth narrower than UWB may be referred to as a narrowband communication system. Of course, narrowband communication system may have other meanings, which are not limited in this application. However, the communication bandwidth of a narrowband communication system may be narrower than the communication bandwidth of a UWB system. The communication bandwidth of a narrowband communication system may typically be understood to be unlicensed national information infrastructure (UNII-3) and UNII-5.

[0063] The embodiments of the present application are primarily described using a WPAN, e.g., a network used in the IEEE 802.15 series of standards, as an example. However, those skilled in the art will readily understand that various aspects of the present application can be extended to other networks using different standards or protocols, such as a wireless local area network (WLAN), Bluetooth, Zigbee protocol, high performance radio LAN (HIPERLAN) (a wireless standard similar to the IEEE 802.11 standard used primarily in Europe), a wide area network (WAN), or other networks now known or developed in the future. Therefore, various aspects provided herein are applicable to any suitable wireless network, regardless of the coverage area and wireless access protocol used.

[0064] The methods provided herein may be implemented by a communication device in a wireless communication system. The communication device may be a device in an UWB system or a WLAN. For example, the communication device may include, but is not limited to, a communication server, a router, a switch, a bridge, a computer, a mobile phone, and the like. In another example, the communication device may include user equipment (UE). The user equipment may include various handheld devices, vehicle-mounted devices (e.g., vehicles or components mounted on vehicles), wearable devices, Internet of Things (IoT) devices, computing devices, or other processing devices connected to a wireless modem. Examples are not listed one by one herein. In another example, the communication device may include a central control node, such as a personal area network (PAN) or PAN coordinator. The PAN coordinator or PAN may be a mobile phone, a vehicle-mounted device, an anchor, a tag, a smart home, etc. In another example, the communication device may be an access point (AP) or a station (STA) of a WLAN. In another example, a communication device may include a chip, which may be located in a communication server, a router, a switch, a terminal device, etc. Examples are not listed one by one herein. The above description of a communication device can be understood to apply to the communication device of the present application.

[0065] Optionally, the communication device in the embodiments of the present application may be a device that supports multiple WPAN standards, such as the currently discussed or later versions of IEEE 802.15.4ab.

[0066] In an embodiment of the present application, a communication device may include a hardware layer, an operating system layer operating above the hardware layer, and an application layer operating above the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also referred to as main memory). The operating system may be any one or more types of computer operating systems that perform service processing through processes, such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a Windows operating system. The application layer includes applications such as a browser, an address book, word processing software, and instant messaging software. In addition, the specific structure of the execution body of the method provided in the embodiment of the present application is not particularly limited to the embodiment of the present application, as long as communication can be performed according to the method provided in the embodiment of the present application by executing a program recording the code of the method provided in the embodiment of the present application.

[0067] For example, FIG. 1 is a structural diagram of a wireless communication system according to an embodiment of the present application. As shown in FIG. 1, the wireless communication system has a star topology structure. In this structure, a central control node (e.g., the PAN coordinator in FIG. 1) may perform data communication with one or more other devices. FIG. 2 is another structural diagram of a wireless communication system according to an embodiment of the present application. As shown in FIG. 2, the wireless communication system has a peer-to-peer topology structure. In this structure, the central control node (e.g., the PAN coordinator in FIG. 2) may perform data communication with one or more other devices, and other devices may also perform data communication with each other. In FIGS. 1 and 2, both full function devices (FFDs) and reduced function devices may be understood as communication devices shown in the present application. A full function device is relative to a reduced function device. For example, a reduced function device cannot be a PAN coordinator. In another example, compared to a full function device, a reduced function device may not have coordination capabilities or may have a lower communication speed than a full function device. It may be understood that the PAN coordinator shown in Figure 2 is merely an example, and each of the other three full-function devices shown in Figure 2 can also be used as a PAN coordinator. Examples are not shown one by one in this specification. It may be further understood that the full-function device and the reduced-function device of the present application are merely examples of communication devices, and any device capable of implementing the channel access method provided in the present application falls within the protection scope of the present application.

[0068] A possible channel access method is shown in Figure 3. Figure 3 is a schematic flowchart of a channel access method according to an embodiment of the present application. When a data packet to be transmitted is in a communication device operating in an unlicensed spectrum, the communication device may perform channel access. As shown in Figure 3, the channel access method may include the following steps:

[0069] (1) Initialize the number of backoff (NB) counter and the backoff exponent (BE). In other words, NB=0 and BE is initialized to its minimum value, i.e., macMinBe. The number of backoffs NB counter is used to record the number of backoffs that occur when a clear channel assignment (CCA) results in the channel being busy. The backoff exponent BE is used to calculate the length of the backoff window (also called the backoff period, multiple backoff periods). It may be understood that in this application the backoff exponent may also be called the backoff factor.

[0070] (2) Implement a random backoff, e.g., a random delay for the backoff period (2*BE or 2 BE ) until backoff periods). The backoff method is linear backoff (e.g., 2*BE) and exponential backoff (e.g., 2 BE ) or both. Backoff means a random wait for a certain period of time. If linear backoff is used, the length of the backoff window (or the duration of the backoff period) is equal to 2*BE, and if exponential backoff is used, the length of the backoff window (or the duration of the backoff period) is equal to 2*BE. BE It may be understood that.

[0071] (3) After backoff is completed, clear channel assignment (CCA) is performed. For example, whether the channel is occupied (in other words, whether the channel is busy) is determined by energy detection (or carrier sense). If the result of CCA is that the channel is idle, in other words, the channel is not occupied, a data packet can be sent (transmitted). If the result of CCA is that the channel is busy, in other words, the channel is occupied, both the backoff exponent BE and the NB counter are increased, for example, BE=min(BE+1,macMaxBe) and NB=NB+1. In this specification, macMaxBe is the maximum value of the backoff exponent BE. min(x,y) indicates that the minimum value of x and y is selected. The same expressions below have the same meaning and will not be explained in detail one by one.

[0072] (4) Determine whether the value of the NB counter exceeds a preset threshold (macMaxCsmaBackoffs), and if the value of the NB counter does not exceed the preset threshold, i.e., NB≦macMaxCsmaBackoffs, re-perform the backoff, i.e., repeat steps (2) and (3); or if the value of the NB counter exceeds the preset threshold, i.e., NB>macMaxCsmaBackoffs, determine whether to send or drop the data packet based on a decision condition (i.e., whether the parameters macBOEEndAction and TxonEnd are equal), and send the data packet if macBOEEndAction is equal to TxonEnd, or drop the data packet if macBOEEndAction is not equal to TxonEnd.

[0073] In the present application, "dropping a data packet" may be understood to mean that the data packet is no longer transmitted during the current channel access. Whether the data packet is transmitted during the next channel access is not limited in the present application. Similar expressions in the following have similar meanings, and details will not be described one by one.

[0074] In FIG. 3, "Y" may be understood to represent "yes" and "N" to represent "no."

[0075] Optionally, the minimum backoff exponent BE (i.e., macMinBe), the maximum backoff exponent BE (i.e., macMaxBe), the preset threshold (i.e., macMaxCsmaBackoffs), macBOEEndAction, and TxonEnd are all configuration parameters at the medium access control (MAC) layer and are generally set by higher layers.

[0076] The purpose of determining whether macBOEEndAction is equal to TxonEnd may be understood to be to select between sending and immediately dropping when the result of performing carrier sensing for a long time indicates that the channel is busy and sending is not possible. Generally, if the result of carrier sensing indicates that the channel is busy, it is appropriate to select dropping. If sending is performed immediately, collisions may increase and performance may deteriorate.

[0077] From the channel access method shown in Figure 3, it can be seen that collision (or contention) avoidance depends on the result of energy detection (or carrier sense). If the result of energy detection (or carrier sense) is that the channel is busy, the backoff period is extended (e.g., the backoff exponent BE is increased), or if the result of energy detection (or carrier sense) is that the channel is idle, a radio frame is sent. However, in a scenario where hidden terminals exist, collision (or contention) may occur even if the result of energy detection (or carrier sense) is that the channel is idle.

[0078] 4 is a diagram of a scenario in which a hidden terminal exists according to an embodiment of the present application. As shown in FIG. 4, the scenario includes Initiator 1, Initiator 2, Tag 1, and Tag 2. The coverage area of ​​Initiator 1 partially overlaps with the coverage area of ​​Initiator 2, and Tag 1 and Tag 2 are within the overlapping area. Initiator 1 is outside the coverage area of ​​Initiator 2, and Initiator 1 is a hidden terminal relative to Initiator 2. Initiator 2 is outside the coverage area of ​​Initiator 1, and Initiator 2 is a hidden terminal relative to Initiator 1. It is assumed that Initiator 1 needs to send information to Tag 1 via a first link, and Initiator 2 needs to send information to Tag 2 via a second link. In this case, Initiator 1 and Initiator 2 perform channel access separately. However, because Initiator 2 is outside the coverage area of ​​Initiator 1, when determining whether the channel is idle through energy detection (or carrier sense), Initiator 1 can only detect whether Tag 1 and Tag 2 have a transmitting behavior (in other words, whether Tag 1 and Tag 2 occupy the channel). Similarly, because Initiator 1 is outside the coverage area of ​​Initiator 2, when determining whether the channel is idle through energy detection (or carrier sense), Initiator 2 can also only detect whether Tag 1 and Tag 2 have a transmitting behavior (in other words, whether the channel is occupied). If neither Tag 1 nor Tag 2 has a sending activity (in other words, the channel is not occupied), the result of Initiator 1's energy detection (or carrier sense) is that the channel is idle, and the result of Initiator 2's energy detection (or carrier sense) is also that the channel is idle. In this case, when Initiator 1 sends information to Tag 1, it is very likely that Initiator 2 also sends information to Tag 2. As a result, a collision occurs. In other words, a collision occurs when the first link and the second link are used for sending at the same time.

[0079] Taking this into consideration, embodiments of the present application provide another channel access method for reducing collisions or contention and improving channel access performance in scenarios where hidden terminals exist (e.g., the scenario shown in FIG. 4) or other scenarios where collisions may exist.

[0080] In the following, the technical solutions provided in this application will be described in detail with reference to more accompanying drawings.

[0081] In this application, unless otherwise specified, identical or similar parts of embodiments or implementations may be referenced to one another. In the embodiments and implementations / methods / implementation methods of the present application, unless otherwise specified or unless a logical conflict occurs, the terms and / or descriptions are consistent and may be referenced to one another between different embodiments and implementations / methods / implementation methods of the embodiments. The technical features in different embodiments and implementations / methods / implementation methods of the embodiments may be combined to form new embodiments, implementations, methods, or implementation methods based on the internal logical relationships of the technical features. The following implementations of this application do not limit the scope of protection of this application. It should be understood that the order of the following embodiments does not represent importance.

[0082] The communication device of the present application may support the 802.15.4ab standard or the next generation standard of 802.15.4ab, may support multiple standards such as 802.15.4a, 802.15.4-2011, 802.15.4-2015, 802.15.4-2020, and 802.15.4z, and may further support WLAN standards of the 802.11 family such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11a, 802.11be, and the next generation standard of 802.11be.

[0083] 5 is another schematic flowchart of a channel access method according to an embodiment of the present application. This method can be applied to the scenario in which a hidden terminal exists as shown in FIG. 4. The communication device of this method can be the initiator 1 or the initiator 2 in FIG. 4. As shown in FIG. 5, the channel access method includes, but is not limited to, the following steps:

[0084] S101: A communication device transmits a first radio frame.

[0085] Optionally, a communication device in an embodiment of the present application communicates in an unlicensed spectrum. Before transmitting the first radio frame, the communication device may perform channel access. In the channel access process, if the result of a clear channel allocation (CCA) is idle, the communication device transmits the first radio frame. Alternatively, when a value of a backoff count (NB) counter exceeds a preset threshold, it is determined to transmit the first radio frame based on a decision condition (e.g., when parameters macBOEEndAction and TxonEnd are equal), and the communication device transmits the first radio frame. Alternatively, the communication device transmits the first radio frame in other cases. The condition for transmitting the first radio frame by the communication device is not limited in the embodiment of the present application.

[0086] Optionally, the first wireless frame may be a wireless frame of an 802.15 series protocol or a wireless frame of an 802.11 series protocol, which is not limited in the embodiments of the present application. Optionally, the first wireless frame may be a wireless frame with a response mechanism. In other words, the device receiving the first wireless frame needs to feed back a corresponding response frame, such as an acknowledgement (ACK) frame or a block ACK (BA), so that the communication device that sends the first wireless frame can confirm that the other device has properly received the first wireless frame.

[0087] S102: If the communication device does not receive a response frame for the first radio frame after sending the first radio frame, the communication device increases the value of a first backoff index and performs backoff based on the increased value of the first backoff index, and the communication device performs clear channel allocation after the backoff is completed, and if the result of the clear channel allocation is that the channel is idle, the communication device sends the first radio frame, or if the result of the clear channel allocation is that the channel is busy, the communication device increases the value of a second backoff index and performs backoff again.

[0088] For example, if a communication device does not receive a response frame for a first radio frame after sending out a first radio frame, the communication device may be understood to determine that a response frame for the first radio frame has not been received after sending out the first radio frame.

[0089] Optionally, the channel access method further includes:

[0090] S103: When the communication device receives a response frame for the first radio frame after sending the first radio frame, the communication device sets the first backoff exponent to the minimum value of the first backoff exponent and performs backoff based on the minimum value of the second backoff exponent; the communication device performs clear channel allocation after the backoff is completed; if the result of the clear channel allocation is that the channel is idle, the communication device sends the second radio frame; or if the result of the clear channel allocation is that the channel is busy, the communication device increases the value of the second backoff exponent and performs backoff again.

[0091] For example, if a communication device receives a response frame for a first radio frame after sending out the first radio frame, it may be understood that the communication device determines that a response frame for the first radio frame has been received after sending out the first radio frame.

[0092] Optionally, after sending the first radio frame, the communication device may detect whether a response frame to the first radio frame is received within a preset time. The preset time may be a time specified in a standard protocol, for example, a short interframe space (SIFS), or the preset time may be determined by two communication parties through negotiation, or the preset time may be pre-set by a central control node (e.g., a PAN coordinator or an AP). This is not limited in the embodiments of the present application.

[0093] If the communication device does not receive a response frame for the first radio frame within a preset time after transmitting the first radio frame, it indicates that the first radio frame was not transmitted (or a collision / contention occurred during the current transmission). In this case, the communication device may increase the value of the first backoff exponent and perform backoff based on the increased value of the first backoff exponent. The first backoff exponent may be used to reflect the backoff caused by the collision. For ease of explanation, BF will be used hereinafter to represent the first backoff exponent. Of course, the first backoff coefficient may be expressed in other ways. For example, the first backoff coefficient may be expressed as BE', BE2, etc. to distinguish it from the second backoff coefficient. For example, if the increased value of the first backoff exponent is less than or equal to the maximum value of the first backoff exponent, the communication device may perform backoff based on the increased value of the first backoff exponent. Alternatively, if the increased value of the first backoff exponent is greater than the maximum value of the first backoff exponent, the communication device may perform backoff based on the maximum value of the first backoff exponent. In other words, the communication device performs backoff based on the value of the first backoff exponent. The value of the first backoff exponent (BF) satisfies BF=min(BF+1, macMaxBF), where macMaxBF represents the maximum value of the first backoff exponent. After backoff is completed, the communication device may perform CCA. If the result of CCA indicates that the channel is idle, the communication device transmits the first radio frame or another radio frame. If the result of CCA indicates that the channel is busy, the communication device increases the value of the second backoff exponent and re-performs backoff. The second backoff exponent may be used to reflect the backoff that occurs when the CCA result indicates that the channel is busy. For ease of explanation, hereinafter, BF is used to represent the second backoff exponent.For example, if the result of the CCA is that the channel is busy, the communication device may increase the value of the second backoff index, and if the increased value of the second backoff index is less than or equal to the maximum value of the second backoff index, the communication device may re-implement backoff based on the increased value of the second backoff index, or if the increased value of the second backoff index is greater than the maximum value of the second backoff index, the communication device may re-implement backoff based on the maximum value of the second backoff index. In other words, if the result of the CCA is that the channel is busy, the communication device re-implements backoff based on the value of the second backoff index. The value of the second backoff index (BE) satisfies BE=min(BE+1,macMaxBe), where macMaxBe represents the maximum value of the second backoff index.

[0094] Optionally, if the communication device receives a response frame for the first radio frame within a preset time after sending the first radio frame, it indicates that the first radio frame has been successfully sent (or that no collision / contention occurred during the current transmission). In this case, the communication device sets the first backoff exponent (BF) to the minimum value of the first backoff exponent and performs backoff based on the minimum value of the second backoff exponent (BE). After the backoff is completed, the communication device may perform CCA. If the result of the CCA indicates that the channel is idle, the communication device sends a second radio frame. If the result of the CCA indicates that the channel is busy, the communication device increases the value of the second backoff exponent and performs backoff again. The second radio frame may be the same as or different from the first radio frame. The second radio frame may also be a radio frame with a response mechanism.

[0095] Optionally, there may be multiple backoff methods, such as linear backoff, exponential backoff, or other backoff (e.g., any monotonically increasing function backoff). In the embodiment of the present application, a specific backoff method is not limited. When linear backoff is used, the length of the backoff window may be 2*BF or 2*BE. When exponential backoff is used, the length of the backoff window may be 2*BF or 2*BE. BF or 2 BE When another backoff method is used, the length of the backoff window may be f(BF) or f(BE), where f(x) represents a monotonically increasing function.

[0096] Optionally, the first back-off index may be different from or the same as the second back-off index. With reference to an example, the following will specifically describe a channel access procedure when the first back-off index is different from the second back-off index and a channel access procedure when the first back-off index is the same as the second back-off index.

[0097] Implementation 1: The first backoff exponent is different from the second backoff exponent.

[0098] In a possible implementation, performing backoff based on an increased value of the first backoff exponent includes: the communication device assigning the increased value of the first backoff exponent to a second backoff exponent, and then performing backoff based on the value of the second backoff exponent. In other words, the value of the first backoff exponent (BF) affects the value of the second backoff exponent (BE).

[0099] For example, Figures 6A and 6B are diagrams of a channel access procedure according to an embodiment of the present application. In Figures 6A and 6B, "Y" may be understood to represent "yes" and "N" to represent "no." When a communication device has a radio frame to be sent, the communication device may enter a channel access procedure. As shown in Figures 6A and 6B, the channel access procedure includes the following steps:

[0100] (1) Initialize the backoff count (NB) counter, i.e., set NB=0.

[0101] (2) Determine whether the previous transmission was successful, i.e., whether the parameter PacketSuccess (such as a data packet success flag or a data packet transmission success flag) is equal to 1. The parameter PacketSuccess may indicate whether the previous transmission was successful or whether a response frame for the transmitted radio frame has been received. If the parameter PacketSuccess is equal to 1, it indicates that the previous transmission was successful. If the parameter PacketSuccess is not equal to 1, it indicates that the previous transmission failed. Specifically, for example, a first radio frame is transmitted in the previous transmission. If a response frame corresponding to the first radio frame is received within a preset time, it indicates that the transmission was successful, and the parameter PacketSuccess may be set to 1. If a response frame corresponding to the first radio frame is not received within a preset time, it indicates that the transmission failed, and the parameter PacketSuccess may be set to 0.

[0102] (3) If the previous transmission was successful, i.e., the parameter PacketSuccess is equal to 1, initialize a first backoff exponent (BF) and a second backoff exponent (BE), e.g., BF=macMinBF, BE=macMinBe, where macMinBF is the minimum value of the first backoff exponent and macMinBe is the minimum value of the second backoff exponent. If the previous transmission was unsuccessful, i.e., the parameter PacketSuccess is not equal to 1, BF is set to min(BF+1,macMaxBF), and then BF is assigned to BE, i.e., BE=BF, where macMaxBF is the maximum value of the first backoff exponent.

[0103] (4) Random backoff, e.g., a random delay for the backoff period (2*BE or 2 BE ) until backoff periods). The length of the backoff window (or the duration of the backoff period) is 2*BE or 2 BE is.

[0104] (5) After the backoff is completed, CCA is performed. If the result of CCA is that the channel is idle, i.e., the channel is not occupied, a radio frame can be sent (transmitted). If the result of CCA is that the channel is busy, i.e., the channel is occupied, both the second backoff exponent (BE) and the backoff count (NB) counter are increased, for example, to BE=min(BE+1,macMaxBe) and NB=NB+1, where macMaxBe is the maximum value of the second backoff exponent.

[0105] (6) Determine whether the value of the backoff count (NB) counter exceeds a preset threshold (macMaxCsmaBackoffs), and if the value of the NB counter does not exceed the preset threshold, i.e., NB≦macMaxCsmaBackoffs, perform backoff again, i.e., repeat steps (4) and (5); or if the value of the NB counter exceeds the preset threshold, i.e., NB>macMaxCsmaBackoffs, determine whether to send (transmit) or drop the wireless frame based on a decision condition (i.e., whether the parameters macBOEEndAction and TxonEnd are equal), and send the wireless frame if macBOEEndAction is equal to TxonEnd, or drop the wireless frame if macBOEEndAction is not equal to TxonEnd.

[0106] (7) After the radio frame is sent, determine whether a response frame (e.g., ACK) for the radio frame has been received. If the response frame for the radio frame has been received within a preset time, the parameter PacketSuccess is set to 1; or, if the response frame for the radio frame has not been received within the preset time, the parameter PacketSuccess is set to 0. It may be understood that whether the parameter PacketSuccess is set to 1 when a response frame has been received or when a response frame has not been received is not limited in the embodiments of the present application. This is merely an example for the purposes of explanation in this specification. In actual application, the parameter PacketSuccess is also set to 0 when a response frame has been received, and the parameter PacketSuccess is set to 1 when a response frame has not been received. Accordingly, step (2) determines whether the parameter PacketSuccess is equal to 0.

[0107] Optionally, the second maximum backoff exponent macMaxBe and the first maximum backoff exponent macMaxBF may be set to the same value or different values, and the first minimum backoff exponent macMinBF and the second minimum backoff exponent macMinBe may be set to the same value or different values.

[0108] In an embodiment of the present application, when a collision occurs (i.e., when no response frame is received after a transmission is performed), the backoff window is increased by increasing the value of BF. In a scenario where a hidden terminal exists, collisions or contentions can be reduced and channel access performance can be improved. In addition, in an embodiment of the present application, the value of BF is assigned to BE to ensure the continuity of the backoff window, so as to avoid a situation where the backoff window is increased due to a transmission collision but is decreased after CCA is performed.

[0109] In another possible implementation, the first backoff exponent and the second backoff exponent are independent of each other, i.e., the value of the first backoff exponent (BF) does not affect the value of the second backoff exponent (BE).

[0110] For example, Figures 7A and 7B are another diagram of a channel access procedure according to an embodiment of the present application. In Figures 7A and 7B, "Y" may be understood to represent "yes" and "N" to represent "no." When a communication device has a radio frame to be sent, the communication device may enter a channel access procedure. As shown in Figures 7A and 7B, the channel access procedure includes the following steps:

[0111] (1) Initialize the backoff count (NB) counter and the second backoff exponent (BE), ie, NB=0 and BE=macMinBF, where macMinBF is the minimum value of the second backoff exponent.

[0112] (2) Determine whether the previous transmission was successful, i.e., whether the parameter PacketSuccess is equal to 1. If the parameter PacketSuccess is equal to 1, it indicates that the previous transmission was successful. If the parameter PacketSuccess is not equal to 1, it indicates that the previous transmission failed. Specifically, for example, the first radio frame is sent in the previous transmission. If a response frame corresponding to the first radio frame is received within a preset time, it indicates that the sending was successful, and the parameter PacketSuccess may be set to 1. If a response frame corresponding to the first radio frame is not received within a preset time, it indicates that the sending failed, and the parameter PacketSuccess may be set to 0.

[0113] (3) If the previous transmission is successful, i.e., if the parameter PacketSuccess is equal to 1, initialize a first backoff exponent (BF), e.g., BF=macMinBF, where macMinBF is the minimum value of the first backoff exponent. After the first backoff exponent (BF) is initialized, a random backoff is performed based on the value of the second backoff exponent (BE), i.e., a random delay (delay for random(2*BE or 2 BE ) until backoff periods) are enforced. The length of the backoff window (or the duration of the backoff period) is 2*BE or 2 BE is.

[0114] (4) If the previous transmission has failed, i.e., the parameter PacketSuccess is not equal to 1, then after BF = min(BF + 1, macMaxBF) is executed, a random backoff is performed based on the value of the first backoff exponent (BF), i.e., a random delay for the backoff period (delay for random(2*BE or 2 BE) until backoff periods), where the length of the backoff window (or the duration of the backoff period) is 2*BF or 2 BF and macMaxBF is the maximum value of the first backoff exponent.

[0115] (5) After the backoff is completed, CCA is performed. If the result of CCA is that the channel is idle, i.e., the channel is not occupied, a radio frame can be sent (transmitted). If the result of CCA is that the channel is busy, i.e., the channel is occupied, both the second backoff exponent (BE) and the backoff count (NB) counter are increased, for example, to BE=min(BE+1,macMaxBe) and NB=NB+1, where macMaxBe is the maximum value of the second backoff exponent.

[0116] (6) Determine whether the value of the backoff count (NB) counter exceeds a preset threshold (macMaxCsmaBackoffs), and if the value of the NB counter does not exceed the preset threshold, i.e., NB≦macMaxCsmaBackoffs, perform backoff again, i.e., repeat steps (4) and (5); or if the value of the NB counter exceeds the preset threshold, i.e., NB>macMaxCsmaBackoffs, determine whether to send (transmit) or drop the wireless frame based on a decision condition (i.e., whether the parameters macBOEEndAction and TxonEnd are equal), and send the wireless frame if macBOEEndAction is equal to TxonEnd, or drop the wireless frame if macBOEEndAction is not equal to TxonEnd.

[0117] (7) After the radio frame is sent, determine whether a response frame (e.g., ACK) for the radio frame has been received. If the response frame for the radio frame has been received within a preset time, the parameter PacketSuccess is set to 1, or if the response frame for the radio frame has not been received within the preset time, the parameter PacketSuccess is set to 0. It may be understood that whether the parameter PacketSuccess is set to 1 when a response frame has been received or when a response frame has not been received is not limited in the embodiments of the present application. This is merely an example for the purpose of explanation in this specification.

[0118] Optionally, the second maximum backoff exponent macMaxBe and the first maximum backoff exponent macMaxBF may be set to the same value or different values, and the first minimum backoff exponent macMinBF and the second minimum backoff exponent macMinBe may be set to the same value or different values.

[0119] In an embodiment of the present application, when a collision occurs (i.e., when no response frame is received after a transmission is performed), the value of BF is increased to increase the backoff window, so that collisions or contentions are reduced in a scenario where a hidden terminal exists and channel access performance is improved. In addition, in an embodiment of the present application, the backoff caused by collisions is separated from the backoff caused when the CCA result is that the channel is busy, so that the independence of the two backoff mechanisms can be ensured and delays can be reduced in a scenario with many collisions.

[0120] Optionally, in Figures 6A, 6B, 7A, and 7B, at least one of macMinBF, macMinBe, macMaxBe, or macMaxBF may be predefined or preconfigured. In an example, at least one of macMinBF, macMinBe, macMaxBe, or macMaxBF may be configured by both communicating parties through dialogue by using a new information element (IE) or by reusing an existing information element (IE). In another example, at least one of macMinBF, macMinBe, macMaxBe, or macMaxBF may be configured by a central control node of another node (e.g., a full-function device) by using a wireless broadcast frame. For example, the communication device may receive configuration parameters from the central control node, which include one or more of the following: macMinBF, macMinBe, macMaxBe, or macMaxBF. The configuration parameters may be carried in a wireless broadcast frame.

[0121] Implementation 2: The first backoff exponent is the same as the second backoff exponent.

[0122] When the first backoff exponent is the same as the second backoff exponent, the second backoff exponent (BE) is used to reflect the backoff caused by collisions and also to reflect the backoff caused when the CCA result is that the channel is busy.

[0123] For example, Figures 8A and 8B are further diagrams of a channel access procedure according to an embodiment of the present application. In Figures 8A and 8B, "Y" may be understood to represent "yes" and "N" to represent "no." When a communication device has a radio frame to be sent, the communication device may enter a channel access procedure. As shown in Figures 8A and 8B, the channel access procedure includes the following steps:

[0124] (1) Initialize the backoff count (NB) counter, i.e., set NB=0.

[0125] (2) Determine whether the previous transmission was successful, i.e., whether the parameter PacketSuccess is equal to 1. If the parameter PacketSuccess is equal to 1, it indicates that the previous transmission was successful. If the parameter PacketSuccess is not equal to 1, it indicates that the previous transmission failed. Specifically, for example, the first radio frame is sent in the previous transmission. If a response frame corresponding to the first radio frame is received within a preset time, it indicates that the sending was successful, and the parameter PacketSuccess may be set to 1. If a response frame corresponding to the first radio frame is not received within a preset time, it indicates that the sending failed, and the parameter PacketSuccess may be set to 0.

[0126] (3) If the previous transmission was successful, i.e., the parameter PacketSuccess is equal to 1, initialize a second backoff exponent (BE), e.g., BE=macMinBe, where macMinBe is the minimum value of the second backoff exponent. If the previous transmission was unsuccessful, i.e., the parameter PacketSuccess is not equal to 1, increase the value of the second backoff exponent, e.g., implement BE=min(BE+1,macMaxBe).

[0127] (4) Random backoff, e.g., a random delay for the backoff period (2*BE or 2 BE ) until backoff periods). The length of the backoff window (or the duration of the backoff period) is 2*BE or 2 BE is.

[0128] (5) After the backoff is completed, CCA is performed. If the result of CCA is that the channel is idle, i.e., the channel is not occupied, a radio frame can be sent (transmitted). If the result of CCA is that the channel is busy, i.e., the channel is occupied, both the second backoff exponent (BE) and the backoff count (NB) counter are increased, for example, to BE=min(BE+1,macMaxBe) and NB=NB+1, where macMaxBe is the maximum value of the second backoff exponent.

[0129] (6) Determine whether the value of the backoff count (NB) counter exceeds a preset threshold (macMaxCsmaBackoffs), and if the value of the NB counter does not exceed the preset threshold, i.e., NB≦macMaxCsmaBackoffs, perform backoff again, i.e., repeat steps (4) and (5); or if the value of the NB counter exceeds the preset threshold, i.e., NB>macMaxCsmaBackoffs, determine whether to send (transmit) or drop the wireless frame based on a decision condition (i.e., whether the parameters macBOEEndAction and TxonEnd are equal), and send the wireless frame if macBOEEndAction is equal to TxonEnd, or drop the wireless frame if macBOEEndAction is not equal to TxonEnd.

[0130] (7) After the radio frame is sent, determine whether a response frame (e.g., ACK) for the radio frame has been received. If the response frame for the radio frame has been received within a preset time, the parameter PacketSuccess is set to 1, or if the response frame for the radio frame has not been received within the preset time, the parameter PacketSuccess is set to 0. It may be understood that whether the parameter PacketSuccess is set to 1 when a response frame has been received or when a response frame has not been received is not limited in the embodiments of the present application. This is merely an example for the purpose of explanation in this specification.

[0131] Optionally, both the minimum value of the second back-off exponent, macMinBe, and the maximum value of the second back-off exponent, macMaxBe, are MAC layer configuration parameters, typically set by higher layers.

[0132] In the embodiment of the present application, when a collision occurs (i.e., when no response frame is received after a transmission is performed), the value of BE is increased to increase the backoff window, so as to reduce collisions or contentions in a scenario where a hidden terminal exists and improve channel access performance. In addition, the implementation of the present application does not introduce a new backoff exponent, so that the implementation is simple, the number of parameters is small, and the complexity is low.

[0133] In the channel access procedures shown in FIGS. 6A to 8B, a backoff count (NB) counter may be understood to be used to record the number of backoffs that occur when the CCA result indicates that the channel is busy. In some possible implementations, a new counter may be used to record the number of backoffs that occur due to collisions. For ease of explanation, the new counter may be referred to as a number of collisions (NC) counter or a first counter. In this application, the name of the new counter is not limited. When the communication device receives a response frame for the first radio frame within a preset time after transmitting the first radio frame, i.e., when the transmission is successful, the communication device sets the NC counter to 0. When the communication device does not receive a response frame for the first radio frame within a preset time after transmitting the first radio frame, i.e., when the transmission is unsuccessful, the communication device increases the value of the NC counter. Referring to any one of Figures 6A and 6B, Figures 7A and 7B, and Figures 8A and 8B, after the parameter PacketSuccess is set to 1 in step (7), the value of the NC counter may be set to 0, and after the parameter PacketSuccess is set to 0, the value of the NC counter may be increased, for example, to NC = NC + 1.

[0134] Optionally, when the value of the NC counter is greater than a first preset threshold or the value of the NB counter is greater than a second preset threshold (i.e., macMaxCsmaBackoffs), the communication device may reset the value of the NC counter to 0.

[0135] In an embodiment of the present application, a new counter is used to record the number of backoffs caused by collisions. The design is more flexible and may not affect the recording of the NB counter. It may be understood that the NB counter may be used to control the maximum number of backoffs for a packet, and the NC counter is used to control the number of times a packet is sent before it is successfully sent. In different scenarios, the maximum value of the NB counter and the maximum value of the NC counter may be set to different values ​​based on different meanings of the NB counter and the NC counter, so that the NB counter and the NC counter can perform counting separately, which is more flexible.

[0136] In some other possible implementations, the NB counter may be used to record all backoffs. In other words, the NB counter records not only the number of backoffs that occurred when the CCA result indicated that the channel was busy, but also the number of backoffs that occurred due to collisions. When the communication device receives a response frame for the first radio frame within a preset time after transmitting the first radio frame, i.e., when the transmission is successful, the communication device sets the NB counter to 0. When the communication device does not receive a response frame for the first radio frame within a preset time after transmitting the first radio frame, i.e., when the transmission is unsuccessful, the communication device increases the value of the NB counter, for example, to NB=NB+1, and the communication device does not initialize the NB counter during the next channel access. Referring to any one of Figures 6A and 6B, Figures 7A and 7B, and Figures 8A and 8B, after the parameter PacketSuccess is set to 1 in step (7), the value of the NB counter may be set to 0, and after the parameter PacketSuccess is set to 0, the value of the NB counter may be increased, for example, to NB = NB + 1, and the step of initializing the NB counter is skipped during the next channel access.

[0137] In an embodiment of the present application, the NB counter is used to record all backoff times so that the life cycle of a packet can be maintained uniformly and the maximum delay can be controlled.

[0138] To better illustrate the beneficial effects of the channel access method provided in the embodiments of the present application, the following uses an example to illustrate the simulation results of throughput and access success probability in a hidden terminal scenario.

[0139] FIG. 9 is a diagram of a simulation of the beneficial effect of an embodiment of the present application. FIG. 9 is a diagram showing the change in the probability of successful access versus delay and the change in throughput versus time after the channel access method according to an embodiment of the present application is used. The horizontal axis is in seconds (s), and delay indicates the period from when a packet enters the send queue to when the packet is successfully sent. Link-0 indicates the first link in the scenario shown in FIG. 4, Link-1 indicates the second link in the scenario shown in FIG. 4, and Total indicates the total throughput of the first and second links. From FIG. 9, it can be seen that the total throughput is significantly improved after the channel access method according to an embodiment of the present application is used. In addition, the initiator of the first link and the initiator of the second link can successfully access the channel and send packets in a short time (about 0.02 s), thereby reducing the sending delay.

[0140] Therefore, according to the channel access method provided in the embodiment of the present application, the backoff window is increased and backoff is performed when collision / contention occurs, so that collision or contention can be reduced in a scenario where a hidden terminal exists (e.g., the scenario shown in FIG. 4) and channel access performance can be improved.

[0141] The foregoing describes in detail the method provided in the present application. To facilitate the implementation of the foregoing solutions in the embodiments of the present application, the embodiments of the present application further provide corresponding apparatuses or devices.

[0142] In the present application, the communication device is divided into functional modules based on the above-mentioned method embodiment. For example, each functional module may be divided into corresponding functions, or two or more functions may be integrated into one processing module. The integrated module may be implemented in the form of hardware or in the form of a software functional module. It should be noted that the module division in the present application is an example and is merely a logical functional division. In actual implementation, other division methods may be used. Below, the communication device in the embodiment of the present application will be described in detail with reference to Figures 10 to 12.

[0143] 10 is a block diagram of a communication device according to an embodiment of the present application. As shown in FIG. 10, the communication device includes a transceiver unit 10 and a processing unit 20.

[0144] the transceiver unit 10 is configured to send a first radio frame, and the processing unit 20 is configured to increase a value of a first backoff exponent when no response frame for the first radio frame is received after the first radio frame is sent, perform backoff based on the increased value of the first backoff exponent, perform clear channel allocation after the backoff is completed, increase a value of a second backoff exponent and re-perform backoff when the result of the clear channel allocation is that the channel is busy, and control the transceiver unit 10 to send the first radio frame when the result of the clear channel allocation is that the channel is idle; and / or The processing unit 20 is further configured to: when a response frame for the first radio frame is received after the first radio frame is sent, set the first backoff exponent to the minimum value of the first backoff exponent, perform backoff based on the minimum value of the second backoff exponent, perform clear channel allocation after the backoff is completed, increase the value of the second backoff exponent and re-perform backoff when the result of the clear channel allocation is that the channel is busy, and control the transceiver unit 10 to send the second radio frame when the result of the clear channel allocation is that the channel is idle.

[0145] In a possible implementation, the processing unit 20 is further configured to perform a backoff based on the increased value of the first backoff exponent when the increased value of the first backoff exponent is less than or equal to a maximum value of the first backoff exponent.

[0146] In a possible implementation, the processing unit 20 is further configured to perform backoff based on a maximum value of the first backoff exponent when the increased value of the first backoff exponent is greater than the maximum value of the first backoff exponent.

[0147] In a possible implementation, the processing unit 20 is particularly configured to perform the backoff based on the value of a second backoff exponent, the value of the second backoff exponent being an increased value of the first backoff exponent.

[0148] In a possible implementation, the first backoff exponent is the same as the second backoff exponent.

[0149] In a possible implementation, the processing unit 20 is further configured to set the value of the collision counter to 0 when a response frame for the first radio frame is received after the first radio frame is sent, and / or to increment the value of the collision counter when no response frame for the first radio frame is received after the first radio frame is sent.

[0150] In a possible implementation, the collision counter is a backoff counter, which is used to record the number of backoffs.

[0151] In a possible implementation, the processing unit 20 is further configured to reset the value of the collision counter to 0 when the incremented value of the collision counter is greater than a preset threshold.

[0152] In a possible implementation, the processing unit 20 is particularly configured to increase the value of the second backoff exponent and, when the increased value of the second backoff exponent is less than or equal to the maximum value of the second backoff exponent, re-implement the backoff based on the increased value of the second backoff exponent, or, when the increased value of the second backoff exponent is greater than the maximum value of the second backoff exponent, re-implement the backoff based on the maximum value of the second backoff exponent.

[0153] In a possible implementation, at least one of the minimum first back-off exponent, the minimum second back-off exponent, the maximum first back-off exponent, and the maximum second back-off exponent is predefined or preset.

[0154] In a possible implementation, the transceiver unit 10 is further configured to receive configuration parameters from a central control node, the configuration parameters including one or more of the following: a minimum value of the first back-off exponent, a minimum value of the second back-off exponent, a maximum value of the first back-off exponent, or a maximum value of the second back-off exponent.

[0155] In a possible implementation, the configuration parameters are carried in radio broadcast frames.

[0156] It may be understood that the specific descriptions of the transceiver unit and the processing unit described in the embodiments of the present application are merely examples. For the specific functions, steps, etc. performed by the transceiver unit and the processing unit, please refer to the aforementioned method embodiments. The details will not be described again in this specification.

[0157] The above describes a communication device in an embodiment of the present application. The following describes possible product forms of the communication device. It should be understood that any product form having the functions of the communication device in FIG. 10 falls within the scope of protection of the embodiment of the present application. It should be further understood that the following description is merely an example, and the product form of the communication device in the embodiment of the present application is not limited thereto.

[0158] In a possible implementation, in the communication device shown in FIG. 10 , the processing unit 20 may be one or more processors, and the transceiver unit 10 may be a transceiver, or the transceiver unit 10 may be a sending unit and a receiving unit. The sending unit may be a transmitter, and the receiving unit may be a receiver. The sending unit and the receiving unit may be integrated into one component, for example, a transceiver. In the embodiment of the present application, the processor and the transceiver may be combined, or the like. The manner of connection between the processor and the transceiver is not limited in the embodiment of the present application. In the process of implementing the above-described method, the process of sending information in the above-described method may be understood as the process of outputting information by the processor. When outputting information, the processor outputs the information to the transceiver, so that the transceiver transmits the information. After the information is output by the processor, other processing may further be performed on the information before it arrives at the transceiver. Similarly, the process of receiving information in the above-described method may be understood as the process of receiving input information by the processor. When the processor receives input information, the transceiver receives the information and inputs the information to the processor. Additionally, after the transceiver receives the information, other processing may need to be performed on the information, in which case the processed information is input to a processor.

[0159] 11 is a structural diagram of a communication device 1000 according to an embodiment of the present application. FIG. 11 shows only the main components of the communication device 1000. In addition to a processor 1001 and a transceiver 1002, the communication device may further include a memory 1003 and an input / output device (not shown).

[0160] The processor 1001 is primarily configured to process communication protocols and communication data, control the entire communication device, execute software programs, and process data from the software programs. The memory 1003 is primarily configured to store software programs and data. The transceiver 1002 may include a control circuit and an antenna. The control circuit is primarily configured to convert between baseband signals and radio frequency signals and process the radio frequency signals. The antenna is primarily configured to receive and transmit radio frequency signals in the form of electromagnetic waves. The input / output device, such as a touch screen, display, or keyboard, is primarily configured to receive data input by a user and output data to the user.

[0161] After the communication device is powered on, the processor 1001 can read the software program in the memory 1003, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be transmitted wirelessly, the processor 1001 performs baseband processing on the data to be transmitted and outputs the baseband signal to the high-frequency circuit. The high-frequency circuit performs high-frequency processing on the baseband signal and then transmits the high-frequency signal to the outside in the form of electromagnetic waves through an antenna. When data is transmitted to the communication device, the high-frequency circuit receives the high-frequency signal through the antenna, converts the high-frequency signal into a baseband signal, and outputs the baseband signal to the processor 1001. The processor 1001 converts the baseband signal into data and processes the data.

[0162] In another implementation, the radio frequency circuitry and antenna may be deployed independently from the processor that performs the baseband processing, e.g., in a distributed scenario, the radio frequency circuitry and antenna may be deployed independently and remotely from the communication device.

[0163] The transceiver 1002 may include a receiver and a transmitter. The receiver is configured to perform receiving functions (or operations), and the transmitter is configured to perform transmitting functions (or operations). The transceiver is configured to communicate with other devices / apparatuses over a transmission medium.

[0164] The processor 1001, the transceiver 1002, and the memory 1003 may be connected via a communication bus.

[0165] For example, the communications device 1000 may be configured to perform the functions of the method embodiments described above. The processor 1001 may be configured to perform step S102 and step S103 of FIG. 5 and / or perform other processes of the techniques described herein. The transceiver 1002 may be configured to perform step S101 of FIG. 5 and / or perform other processes of the techniques described herein.

[0166] Optionally, the processor 1001 may include a transceiver configured to implement receiving and transmitting functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit configured to implement receiving and transmitting functions may be separate or integrated. The transceiver circuit, interface, or interface circuit may be configured to read and write code / data. Alternatively, the transceiver circuit, interface, or interface circuit may be configured to transmit or forward signals.

[0167] Optionally, the processor 1001 may store instructions. The instructions may be a computer program. The computer program runs on the processor 1001 so that the communication device 1000 performs the methods described in the above method embodiments. The computer program may be fixed in the processor 1001. In this case, the processor 1001 may be implemented by hardware.

[0168] In some implementations, the communications device 1000 may include circuitry that may implement the transmit, receive, or communication functions of the aforementioned method embodiments. The processors and transceivers described herein may be implemented in integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed-signal ICs, application-specific integrated circuits (ASICs), printed circuit boards (PCBs), electronic devices, etc. The processors and transceivers may alternatively be fabricated using various IC technologies, such as complementary metal oxide semiconductor (CMOS), n-type metal oxide semiconductor (NMOS), p-type metal oxide semiconductor (PMOS), bipolar junction transistor (BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), or gallium arsenide (GaAs).

[0169] It may be understood that the communication device shown in the embodiment of the present application may further have more components and the like than those in FIG. 11 , which is not limited in the embodiment of the present application. The above-described method implemented by the processor and the transceiver is merely an example. For specific steps implemented by the processor and the transceiver, please refer to the description in the above-described method embodiment.

[0170] In another possible implementation, in the communication device shown in FIG. 10, the processing unit 20 may be one or more logic circuits, and the transceiver unit 10 may be an input / output interface, or may be referred to as a communication interface, an interface circuit, an interface, etc. Alternatively, the transceiver unit 10 may be a sending unit and a receiving unit. The sending unit may be an output interface, and the receiving unit may be an input interface. The sending unit and the receiving unit are integrated into one unit, for example, an input / output interface. FIG. 12 is another structural diagram of a communication device according to an embodiment of the present application. As shown in FIG. 12, the communication device shown in FIG. 12 includes a logic circuit 901 and an interface 902. That is, the processing unit 20 may be implemented using the logic circuit 901, and the transceiver unit 10 may be implemented using the interface 902. The logic circuit 901 may be a chip, a processing circuit, an integrated circuit, a system-on-chip (SoC) chip, etc. The interface 902 may be a communication interface, an input / output interface, a pin, etc. For example, FIG. 12 illustrates an example in which the communication device is a chip. The chip includes a logic circuit 901 and an interface 902 .

[0171] In the embodiments of the present application, the logic circuit and the interface may be further coupled to each other, and the specific manner of connection between the logic circuit and the interface is not limited in the embodiments of the present application.

[0172] For example, when the communication device is configured to perform the method, function, or step performed by the communication device of the aforementioned method embodiment, the interface 902 is configured to output a first radio frame, and the logic circuit 901 is configured to: increase a value of a first backoff exponent if no response frame for the first radio frame is received after the first radio frame is sent; perform a backoff based on the increased value of the first backoff exponent; perform a clear channel assignment after the backoff is completed; increase a value of a second backoff exponent and re-perform a backoff when the clear channel assignment results in the channel being busy; and control the interface 902 to output the first radio frame when the clear channel assignment results in the channel being idle; and / or The logic circuit 901 is further configured to: when a response frame for the first radio frame is received after the first radio frame is sent, set the first backoff exponent to the minimum value of the first backoff exponent, perform backoff based on the minimum value of the second backoff exponent, perform clear channel allocation after the backoff is completed, increase the value of the second backoff exponent and re-perform backoff when the result of the clear channel allocation is that the channel is busy, and control the interface 902 to output the second radio frame when the result of the clear channel allocation is that the channel is idle.

[0173] For a specific description of the logic circuit 901 and the interface 902, please refer to the description of the processing unit and the transceiver unit shown in Figure 10. The details will not be described again here.

[0174] It should be understood that the communication device shown in the embodiments of the present application may implement the methods provided in the embodiments of the present application in the form of hardware, or may implement the methods provided in the embodiments of the present application in the form of software, which is not limited in the embodiments of the present application.

[0175] For specific implementation of the embodiment shown in Figure 12, please refer to the aforementioned embodiment, and the details will not be described again in this specification.

[0176] The present application further provides a computer-readable storage medium that stores computer code that, when run on a computer, enables the computer to perform the operations and / or processes performed by the communication device in the manner provided herein.

[0177] The present application further provides a computer program, which is used to implement the actions and / or processes performed by the communication device in the methods provided in the present application.

[0178] The present application further provides a computer program product, which includes computer code or a computer program that, when run on a computer, performs the operations and / or processes performed by the communication device in the methods provided herein.

[0179] In some embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the described device embodiments are merely examples. For example, the division into units is merely a logical division of function, and other divisions may be used in actual implementation. For example, multiple units or components may be combined or integrated to form another system, or some features may be omitted or not implemented. In addition, the shown or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces, and indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms of connection.

[0180] The units described as separate parts may or may not be physically separated, and the parts shown as units may or may not be physical units, and may be located in one location or distributed across multiple network units. Some or all of the units may be selected based on the actual requirements for implementing the technical effects of the solutions provided in the embodiments of the present application.

[0181] In addition, the functional units of the embodiments of the present application may be integrated into one processing unit, each of the units may exist physically alone, or two or more units may be integrated into one unit. The integrated unit may be implemented in the form of hardware or in the form of a software functional unit.

[0182] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, the integrated unit may be stored in a computer-readable storage medium. Based on such understanding, the essential technical solution of the present application, or a portion contributing to the prior art, or all or a portion of the technical solution may be embodied in the form of a software product. The computer software product is stored in a readable storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device) to execute all or a portion of the steps of the method described in the embodiments of the present application. The readable storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0183] The above description is merely a specific implementation of the present application, but does not limit the scope of protection of the present application. Any variations or replacements that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application shall fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the scope of protection of the claims.

Claims

1. 1. A channel access method, comprising: transmitting a first radio frame by a communication device; a step of increasing a value of a first backoff exponent by the communication device and performing backoff based on the increased value of the first backoff exponent when the communication device does not receive a response frame for the first radio frame after sending the first radio frame; a step of performing a clear channel assignment by the communication device after the backoff is completed; a step of sending the first radio frame by the communication device when the result of the clear channel assignment is that the channel is idle, or a step of increasing a value of a second backoff exponent by the communication device and performing backoff again when the result of the clear channel assignment is that the channel is busy; and / or When the communication device receives the response frame for the first radio frame after transmitting the first radio frame, the communication device sets the first backoff exponent to a minimum value of the first backoff exponent and performs backoff based on the minimum value of the second backoff exponent; performs clear channel assignment by the communication device after the backoff is completed; transmits a second radio frame by the communication device if the result of the clear channel assignment indicates that the channel is idle, or increases the value of the second backoff exponent by the communication device and performs backoff again if the result of the clear channel assignment indicates that the channel is busy. A channel access method including:

2. The method comprises:

2. The method of claim 1, further comprising: if the increased value of the first backoff exponent is less than or equal to a maximum value of the first backoff exponent, implementing a backoff by the communication device based on the increased value of the first backoff exponent.

3. 2. The method of claim 1, further comprising: if the increased value of the first backoff exponent is greater than a maximum value of the first backoff exponent, implementing a backoff by the communication device based on the maximum value of the first backoff exponent.

4. The step of performing a backoff based on an increased value of the first backoff exponent comprises:

4. The method of claim 1, further comprising: implementing a backoff based on the value of the second backoff exponent, the value of the second backoff exponent being the increased value of the first backoff exponent.

5. The method of claim 1 , wherein the first back-off exponent is the same as the second back-off exponent.

6. After the step of sending a first radio frame by the communication device, the method further comprises: setting a value of a collision counter to 0 by the communication device when the communication device receives the response frame to the first radio frame after transmitting the first radio frame; and / or Incrementing a value of a collision counter by the communication device when the communication device does not receive the response frame for the first wireless frame after transmitting the first wireless frame. The method of claim 1 , further comprising:

7. 7. The method of claim 6, wherein the collision number counter is a backoff number counter, and the backoff number counter is used to record the number of backoffs.

8. The method comprises:

8. The method according to claim 6, further comprising the step of resetting the value of the collision counter to 0 by the communication device when the incremented value of the collision counter is greater than a preset threshold value.

9. The step of increasing the second backoff exponent by the communication device and re-performing backoff includes: increasing the value of the second back-off exponent by the communication device; if the increased value of the second backoff exponent is less than or equal to the maximum value of the second backoff exponent, re-implementing a backoff based on the increased value of the second backoff exponent by the communication device; or if the increased value of the second backoff exponent is greater than the maximum value of the second backoff exponent, re-implementing a backoff based on the maximum value of the second backoff exponent by the communication device; 9. The method of claim 1, comprising:

10. 10. The method of claim 1, wherein at least one of the minimum value of the first back-off exponent, the minimum value of the second back-off exponent, the maximum value of the first back-off exponent, and the maximum value of the second back-off exponent is predefined or preset.

11. Prior to the step of sending a first radio frame by the communication device, the method further comprises:

11. The method of claim 1, further comprising receiving, by the communication device, configuration parameters from a central control node, the configuration parameters comprising one or more of the following: the minimum value of the first back-off exponent, the minimum value of the second back-off exponent, the maximum value of the first back-off exponent, or the maximum value of the second back-off exponent.

12. The method of claim 11 , wherein the configuration parameters are carried in a wireless broadcast frame.

13. A communication device, a transceiver unit configured to transmit a first radio frame; a processing unit configured to increase a value of a first backoff exponent when a response frame for the first radio frame is not received after the first radio frame is sent, to perform backoff based on the increased value of the first backoff exponent, to perform clear channel assignment after the backoff is completed, to increase a value of a second backoff exponent and perform backoff again when the result of the clear channel assignment is that the channel is busy, and to control the transceiver unit to send the first radio frame when the result of the clear channel assignment is that the channel is idle; and / or a processing unit further configured to: when a response frame to the first radio frame is received after the first radio frame is sent, set the first backoff exponent to a minimum value of the first backoff exponent, perform backoff based on the minimum value of the second backoff exponent, perform clear channel assignment after the backoff is completed, increase the value of the second backoff exponent and perform backoff again when the result of the clear channel assignment is that the channel is busy, and control the transceiver unit to send a second radio frame when the result of the clear channel assignment is that the channel is idle; A communication device comprising:

14. 14. The apparatus of claim 13, wherein the processing unit is further configured to implement a backoff based on the increased value of the first backoff exponent when the increased value of the first backoff exponent is less than or equal to a maximum value of the first backoff exponent.

15. 14. The apparatus of claim 13, wherein the processing unit is further configured to implement a backoff based on a maximum value of the first backoff exponent when the increased value of the first backoff exponent is greater than the maximum value of the first backoff exponent.

16. 16. The apparatus of claim 13, wherein the processing unit is specifically configured to implement backoff based on a value of the second backoff exponent, the value of the second backoff exponent being the increased value of the first backoff exponent.

17. 17. The apparatus of claim 13, wherein the first back-off exponent is the same as the second back-off exponent.

18. The processing unit setting a value of a collision counter to 0 when the response frame to the first radio frame is received after the first radio frame is transmitted; and / or When a response frame to the first radio frame is not received after the first radio frame is transmitted, the value of the collision counter is increased.

18. The apparatus of any one of claims 13 to 17, further configured to:

19. 20. The apparatus of claim 18, wherein the collision number counter is a backoff number counter, and the backoff number counter is used to record the number of backoffs.

20. 20. The apparatus according to claim 18 or 19, wherein the processing unit is further configured to reset the value of the collision counter to 0 when the incremented value of the collision counter is greater than a preset threshold value.

21. The processing unit increasing the value of the second backoff exponent; re-performing a backoff based on the increased value of the second backoff exponent when the increased value of the second backoff exponent is less than or equal to the maximum value of the second backoff exponent; or When the increased value of the second backoff exponent is greater than the maximum value of the second backoff exponent, re-perform the backoff based on the maximum value of the second backoff exponent.

21. Apparatus according to any one of claims 13 to 20, specifically adapted to:

22. 22. The apparatus of claim 13, wherein at least one of the minimum value of the first back-off exponent, the minimum value of the second back-off exponent, the maximum value of the first back-off exponent, and the maximum value of the second back-off exponent is predefined or preset.

23. 23. The apparatus of claim 13, wherein the transceiver unit is further configured to receive configuration parameters from a central control node, the configuration parameters including one or more of the following: the minimum value of the first back-off exponent, the minimum value of the second back-off exponent, the maximum value of the first back-off exponent, or the maximum value of the second back-off exponent.

24. 24. The apparatus of claim 23, wherein the configuration parameters are carried in wireless broadcast frames.

25. a processor and a memory; the memory configured to store instructions; A communications device, wherein the processor is configured to execute the instructions, thereby performing the method of any one of claims 1 to 13.

26. a logic circuit and an interface, the logic circuit coupled to the interface; 13. A communications device, wherein the interface is configured to input and / or output code instructions, and the logic circuit is configured to execute the code instructions, thereby performing a method according to any one of claims 1 to 12.

27. 13. A computer-readable storage medium configured to store a computer program, the computer program, when executed, performing the method of any one of claims 1 to 12.

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