Channel access method and related device

Abstract

The embodiment of the invention discloses a channel access method and a related device, and the method comprises the steps: when a corresponding response frame is not received after a communication device sends a frame, increasing the value of a backoff index, executing backoff, executing CCA after the backoff, if the CCA result is idle, sending, and if the CCA result is busy, performing backoff again. By adopting the embodiment of the invention, conflicts or collisions can be reduced in the presence of hidden terminals, and the performance of channel access is improved. The application is applied to a WAPN (Wireless Access Point Name) system, a sensing system and the like based on UWB (Ultra Wideband), and comprises 802.15 series protocols, such as an 802.15. 4 ab protocol or a next-generation UWB protocol and the like; and the method can also be applied to wireless local area network systems of 802.11 series protocols, such as 802.11 be or the next generation thereof, Wi-Fi 8 and the like.

Description

[0001] This application is a divisional application. The application number of the original application is 202211378676.5, and the original application date is November 4, 2022. The entire contents of the original application are incorporated into this application by reference. Technical Field

[0002] The present application relates to the field of wireless communication technology, and in particular to a channel access method and related devices. Background Art

[0003] A key technology in unlicensed spectrum is channel access. The purpose of channel access is to use the spectrum efficiently while ensuring user fairness, that is, to maximize spectrum efficiency. Carrier sense multiple access (CSMA) is a commonly used channel access method. Before channel access, energy detection (or carrier sense) is performed to determine whether the channel is busy or idle. Only when the channel is idle is transmission allowed. In order to further reduce conflicts, a random backoff mechanism is also used in CSMA, that is, random waiting for a period of time.

[0004] Because the avoidance of conflicts (or collisions) in the existing CSMA depends on the result of energy detection (or carrier sensing), if the result of energy detection (or carrier sensing) is that the channel is busy, the backoff time is increased; if the result of energy detection (or carrier sensing) is that the channel is idle, the wireless frame is sent. However, in the scenario where there are hidden terminals, even if the result of energy detection (or carrier sensing) is that the channel is idle, conflicts (or collisions) may still occur. Therefore, the existing channel access technology has the problems of frequent collisions and deteriorated performance in the scenario where there are hidden terminals. Summary of the invention

[0005] The embodiments of the present application provide a channel access method and related devices, which can reduce conflicts or collisions and improve the performance of channel access in a scenario where a hidden terminal exists.

[0006] The present application is introduced below from different aspects. It should be understood that the implementation methods and beneficial effects of the following different aspects can be referenced to each other.

[0007] In a first aspect, the present application provides a channel access method, which is applied to a scenario where a hidden terminal exists, and the method includes: a communication device sends a first wireless frame, and detects whether a response frame to the first wireless frame is received within a preset time after the sending; if a response frame to the first wireless frame is not received, the communication device increases the value of a first backoff index, and backs off according to the increased value of the first backoff index. After the backoff is completed, the communication device performs an idle channel evaluation. If the result of the idle channel evaluation is that the channel is idle, the communication device sends the first wireless frame. If the result of the idle channel evaluation is that the channel is busy, the communication device increases the value of a second backoff index and backs off again; and / or, if a response frame to the first wireless frame is received, the communication device sets the first backoff index to the minimum value of the first backoff index, and backs off according to the minimum value of the second backoff index. After the backoff is completed, the communication device performs an idle channel evaluation. If the result of the idle channel evaluation is that the channel is idle, the communication device sends a second wireless frame. If the result of the idle channel evaluation is that the channel is busy, the communication device increases the value of the second backoff index and backs off again.

[0008] The first backoff index may be used to reflect the backoff caused by a conflict, and the second backoff index may be used to reflect the backoff caused by a clear channel assignment (CCA) result indicating that the channel is busy.

[0009] It is understandable that there may be multiple backoff methods, such as linear backoff or exponential backoff. The specific backoff method is not limited in this application.

[0010] When no corresponding response is received after sending a wireless frame, that is, when a conflict / collision occurs, the present application increases the value of the first backoff number to increase the backoff window and perform backoff, which can reduce conflicts or collisions and improve channel access performance in scenarios where hidden terminals exist.

[0011] In combination with the first aspect, in a possible implementation, after the communication device increases the value of the first backoff index, the method also includes: if the increased value of the first backoff index is less than or equal to the maximum value of the first backoff index, the communication device backs off according to the increased value of the first backoff index.

[0012] Optionally, if the increased value of the first backoff index is greater than the maximum value of the first backoff index, the communication device backs off according to the maximum value of the first backoff index.

[0013] In combination with the first aspect, in a possible implementation, backing off according to the increased value of the first backoff index includes: assigning the increased value of the first backoff index to the second backoff index, and then backing off according to the value of the second backoff index. In other words, the value of the first backoff index will affect the value of the second backoff index.

[0014] The present application assigns the value of the first backoff index to the second backoff index, and performs backoff according to the second backoff index to ensure the continuity of the backoff window, which can prevent the backoff window from increasing due to a sending conflict, but the backoff window becomes smaller after CCA.

[0015] In conjunction with the first aspect, in a possible implementation, the first backoff index and the second backoff index may be the same. When the first backoff index and the second backoff index are the same, the present application does not introduce a new backoff index, which is simple to implement, has few parameters, and low complexity.

[0016] In combination with the first aspect, in a possible implementation, after the communication device sends the first wireless frame, the method also includes: when the communication device receives a response frame to the first wireless frame after sending the first wireless frame, the communication device sets the conflict number counter to 0; when the communication device does not receive a response frame to the first wireless frame after sending the first wireless frame, the communication device increases the value of the conflict number counter.

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

[0018] This application adopts a new counter (conflict count counter) to record the number of backoffs caused by conflicts. The design is more flexible and does not affect the records of the original backoff count counter.

[0019] Optionally, the above-mentioned conflict count counter is a backoff count counter. The backoff count counter is used to record the backoff count caused by the CCA result being that the channel is busy.

[0020] The present application uses a backoff counter to record all backoff times, which can reduce the delay of a channel access in a scenario with more conflicts, allowing it to enter the next channel access faster.

[0021] In combination with the first aspect, in a possible implementation method, the communication device increases the value of the second backoff index and re-backs off, including: the communication device increases the value of the second backoff index; 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 re-backs off according to the increased value of the second backoff index; if the increased value of the second backoff index is greater than the maximum value of the second backoff index, the communication device re-backs off according to the maximum value of the second backoff index.

[0022] In combination with the first aspect, in a possible implementation manner, at least one of the minimum value of the first backoff index, the minimum value of the second backoff index, the maximum value of the first backoff index, and the maximum value of the second backoff index is predefined or preconfigured.

[0023] In combination with the first aspect, in a possible implementation, before the communication device sends the first wireless frame, the method also includes: the communication device receives a configuration parameter from a central control node, and the configuration parameter includes one or more of the following: a minimum value of a first backoff index, a minimum value of a second backoff index, a maximum value of the first backoff index, or a maximum value of a second backoff index.

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

[0025] In a second aspect, the present application provides a communication device, including a transceiver unit and a processing unit. The transceiver unit is used to send a first wireless frame; the processing unit is used to increase the value of a first backoff index if no response frame is received for the first wireless frame after the first wireless frame is sent, and back off according to the increased value of the first backoff index, and perform idle channel evaluation after the backoff is completed, and when the result of the idle channel evaluation is that the channel is busy, increase the value of a second backoff index and back off again, and control the transceiver unit to send the first wireless frame when the result of the idle channel evaluation is that the channel is idle;

[0026] and / or;

[0027] The processing unit is also used to, when a response frame to the first wireless frame is received after sending the first wireless frame, set the first backoff index to the minimum value of the first backoff index, and perform backoff according to the minimum value of the second backoff index, and perform idle channel evaluation after the backoff is completed, and when the result of the idle channel evaluation is that the channel is busy, increase the value of the second backoff index and perform backoff again, and control the transceiver unit to send the second wireless frame when the result of the idle channel evaluation is that the channel is idle.

[0028] In combination with the second aspect, in a possible implementation, the above-mentioned processing unit is also used to back off according to the increased value of the first backoff index when the increased value of the first backoff index is less than or equal to the maximum value of the first backoff index.

[0029] In combination with the second aspect, in a possible implementation, the processing unit is further configured to back off according to the maximum value of the first backoff index when the increased value of the first backoff index is greater than the maximum value of the first backoff index.

[0030] In combination with the second aspect, in a possible implementation manner, the above-mentioned processing unit is specifically used to back off according to the value of a second back off index, and the value of the second back off index is the increased value of the first back off index.

[0031] In combination with the second aspect, in a possible implementation manner, the first backoff index is the same as the second backoff index.

[0032] In combination with the second aspect, in a possible implementation method, the above-mentioned processing unit is also used to: when a response frame for the first wireless frame is received after sending the first wireless frame, set the conflict number counter to 0; when no response frame for the first wireless frame is received after sending the first wireless frame, increase the value of the conflict number counter.

[0033] Optionally, the above-mentioned conflict count counter is a backoff count counter, and the backoff count counter is used to record the backoff count caused by the CCA result being a busy channel.

[0034] Optionally, the processing unit is further configured to reset the conflict count counter to 0 when the incremented value of the conflict count counter is greater than a preset threshold.

[0035] In combination with the second aspect, in a possible implementation method, the above-mentioned processing unit is specifically used to: increase the value of the second backoff index; when the increased value of the second backoff index is less than or equal to the maximum value of the second backoff index, re-backoff according to the increased value of the second backoff index; when the increased value of the second backoff index is greater than the maximum value of the second backoff index, re-backoff according to the maximum value of the second backoff index.

[0036] In combination with the second aspect, in a possible implementation manner, at least one of the minimum value of the first backoff index, the minimum value of the second backoff index, the maximum value of the first backoff index, and the maximum value of the second backoff index is predefined or preconfigured.

[0037] In combination with the second aspect, in a possible implementation method, the above-mentioned transceiver unit is also used to receive configuration parameters from the central control node, and the configuration parameters include one or more of the following: the minimum value of the first backoff index, the minimum value of the second backoff index, the maximum value of the first backoff index, or the maximum value of the second backoff index.

[0038] Optionally, the above configuration parameters are carried in a wireless broadcast frame.

[0039] In a third aspect, the present application provides a communication device, the communication device comprising a processor, configured to execute the method described in the first aspect or any possible implementation of the first aspect. Alternatively, the processor is configured to execute a program stored in a memory, and when the program is executed, the method described in the first aspect or any possible implementation of the first aspect is executed.

[0040] In combination with the third aspect, in a possible implementation manner, the memory is located outside the above-mentioned communication device.

[0041] In combination with the third aspect, in a possible implementation manner, the memory is located within the above-mentioned communication device.

[0042] In the embodiment of the present application, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together.

[0043] In combination with the third aspect, in a possible implementation manner, the communication device further includes a transceiver, where the transceiver is used to receive a response frame or send a wireless frame.

[0044] In a fourth aspect, the present application provides a communication device, which includes a logic circuit and an interface, and the logic circuit is coupled to the interface. The interface is used to output a first wireless frame; the logic circuit is used to increase the value of a first backoff index when no response frame is received for the first wireless frame after the first wireless frame is sent, and back off according to the increased value of the first backoff index, and perform idle channel evaluation after the back off is completed, and when the result of the idle channel evaluation is that the channel is busy, increase the value of a second backoff index and back off again, and the control interface outputs the first wireless frame when the result of the idle channel evaluation is that the channel is idle;

[0045] And / or; the logic circuit is also used to set the first backoff index to the minimum value of the first backoff index when a response frame to the first wireless frame is received after sending the first wireless frame, and back off according to the minimum value of the second backoff index, and perform idle channel evaluation after the backoff is completed, and when the result of the idle channel evaluation is that the channel is busy, increase the value of the second backoff index and back off again, and control the interface to output the second wireless frame when the result of the idle channel evaluation is that the channel is idle.

[0046] In a fifth aspect, the present application provides a computer-readable storage medium for storing a computer program, which, when executed on a computer, enables the method shown in the above-mentioned first aspect or any possible implementation of the first aspect to be executed.

[0047] In a sixth aspect, the present application provides a computer program product, which includes a computer program or a computer code, and when the computer program product is run on a computer, the method shown in the above-mentioned first aspect or any possible implementation of the first aspect is executed.

[0048] In a seventh aspect, the present application provides a computer program. When the computer program runs on a computer, the method shown in the above-mentioned first aspect or any possible implementation of the first aspect is executed.

[0049] The technical effects achieved in the above-mentioned aspects can be referred to each other or to the beneficial effects in the method embodiments shown below, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a structural diagram of a wireless communication system provided in an embodiment of the present application;

[0051] Figure 2 is another structural diagram of a wireless communication system provided in an embodiment of the present application;

[0052] Figure 3 This is a flow chart of a channel access method provided in an embodiment of the present application;

[0053] Figure 4 This is a schematic diagram of a scenario in which a hidden terminal exists provided in an embodiment of the present application;

[0054] Figure 5 It is another flow chart of the channel access method provided in the embodiment of the present application;

[0055] Figure 6 This is a schematic diagram of a channel access process provided by an embodiment of the present application;

[0056] Figure 7 is another schematic diagram of the channel access process provided in an embodiment of the present application;

[0057] Figure 8 This is another schematic diagram of the channel access process provided in the embodiment of the present application;

[0058] Fig. 9 It is a simulation schematic diagram of the beneficial effects provided by the embodiment of the present application;

[0059] Fig.10 is a schematic diagram of a structure of a communication device provided in an embodiment of the present application;

[0060] Fig.11 is a schematic diagram of the structure of a communication device 1000 provided in an embodiment of the present application;

[0061] Fig.12 It is another structural schematic diagram of the communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0062] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0063] In the description of this application, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c; a and b; a and c; b and c; or a, b, and c. Among them, a, b, and c can be single or multiple.

[0064] The terms "first" and "second" in this application are only used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any 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 steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0065] The "embodiment" mentioned in this article means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It can be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0066] In this application, the words "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described in this application as "exemplary", "for example" or "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the words "exemplary", "for example" or "for example" is intended to present the related concepts in a concrete way.

[0067] It should be understood that in the present application, "when", "if" and "if" all mean that the device will take corresponding actions under certain objective circumstances, and do not limit the time, nor do they require that the device must have a judgment action when it is implemented, nor do they mean that there are other limitations.

[0068] Elements used in the singular herein are intended to mean "one or more" rather than "one and only one" unless specifically stated otherwise.

[0069] Additionally, the terms "system" and "network" are often used interchangeably herein.

[0070] It should be understood that in the embodiments of the present application, determining B based on A does not mean determining B only based on A, but B can also be determined based on A and / or other information.

[0071] The technical solution provided in this application can be applied to various networks in unlicensed spectrum, which are not listed here one by one. For example, the technical solution provided in this application can be applied to wireless personal area networks (WPAN) based on ultra-wideband (UWB) technology. For example, the method provided in this application can be applied to the Institute of Electrical and Electronics Engineers (IEEE) 802.15 series protocols, such as the 802.15.4ab protocol, or a future generation of UWB WPAN standards, which are not listed here one by one. For another example, the technical solution provided in this application can also be applied to wireless local area networks (WLAN) of the 802.11 series protocols, such as the method provided in this application can be applied to 802.11ax, 802.11be or its next generation, such as Wi-Fi8 (also known as ultra-high reliability (UHR) or ultra-high reliability and throughput (UHRT)), etc., which are not listed here one by one.

[0072] It should be understood that the network architecture described in the embodiments of the present application is for the purpose of more clearly illustrating the technical solutions of the embodiments of the present application, and does not constitute a limitation on the technical solutions provided in the embodiments of the present application. A person of ordinary skill in the art can know that with the evolution of the network architecture, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0073] Some scenarios in the embodiments of the present application are explained using UWB communication scenarios in wireless personal area networks as examples. It should be understood that the solutions in the embodiments of the present application can also be applied to other wireless communication networks, and the corresponding names can also be replaced by the names of corresponding functions in other wireless communication networks.

[0074] UWB technology is a new type of wireless communication technology. It uses nanosecond non-sinusoidal narrow pulses to transmit data. By modulating impulse pulses with very steep rise and fall times, the spectrum range it occupies is very wide, making the signal have a bandwidth of the order of GHz. The bandwidth used by UWB is usually above 1GHz. Because the UWB system does not need to generate a sinusoidal carrier signal and can directly transmit an impulse sequence, the UWB system has a very wide spectrum and very low average power. The UWB wireless communication system has the advantages of strong multipath resolution, low power consumption, and strong confidentiality, which is conducive to coexistence with other systems, thereby improving spectrum utilization and system capacity. In addition, in short-distance communication applications, the transmission power of the UWB transmitter can usually be less than 1mW (milliwatt). Theoretically, the interference generated by the UWB signal is only equivalent to white noise. This helps the good coexistence between ultra-wideband and existing narrowband communications. Therefore, the UWB system can work simultaneously with the narrowband (NB) communication system without interfering with each other.

[0075] The method provided in the present application can be implemented by a communication device in a wireless communication system. In a communication device, a device or chip that implements the UWB system function can be called a UWB module, and a device or chip that implements the narrowband communication system function can be called a narrowband communication module. The UWB module and the narrowband communication module can be different devices or chips. Of course, the UWB module and the narrowband communication module can also be integrated in one device or chip. The embodiments of the present application do not limit the implementation of the UWB module and the narrowband communication module in the communication device. The communication device in the present application includes a UWB module and / or a narrowband communication module.

[0076] It is understood that in this application, narrowband is relative to UWB. Any communication system that works at a bandwidth narrower than UWB can be called a narrowband communication system. Of course, narrowband communication system can also have other meanings, which are not limited in this application, but the communication bandwidth of a narrowband communication system can be smaller than the communication bandwidth of a UWB system. It is also understood that the communication bandwidth of a narrowband communication system is usually UNII-3 (unlicensed national information infrastructure) and UNII-5.

[0077] Although the embodiments of the present application mainly take WPAN as an example, for example, a network applied to the IEEE 802.15 series standard is used as an example for explanation. It is easy for those skilled in the art to understand that the various aspects involved in the present application can be extended to other networks using various standards or protocols. For example, wireless local area networks (WLAN), Bluetooth (BLUETOOTH), Zigbee (Zigbee protocol), high performance wireless LAN (HIPERLAN) (a wireless standard similar to the IEEE 802.11 standard, mainly used in Europe) and wide area network (WAN) or other networks now known or developed later. Therefore, regardless of the coverage range and wireless access protocol used, the various aspects provided in the present application can be applied to any suitable wireless network.

[0078] The method provided in the present application can be implemented by a communication device in a wireless communication system. The communication device can be a device involved in a UWB system or a WLAN. For example, the communication device can include but is not limited to a communication server, a router, a switch, a bridge, a computer, a mobile phone, etc. For another example, the communication device may include a user equipment (UE), which may include various handheld devices, vehicle-mounted devices (such as cars or components installed on cars, etc.), wearable devices, Internet of Things (IoT) devices, computing devices, or other processing devices connected to a wireless modem, etc., which are not listed here one by one. For another example, the communication device may include a central control node, such as a personal area network (PAN) or a PAN coordinator, etc. The PAN coordinator or PAN can be a mobile phone, a vehicle-mounted device, an anchor point (Anchor), a tag (tag) or a smart home, etc. For another example, the communication device can be an access point (AP) or a station (STA) in a WLAN. For another example, the communication device may include a chip, which can be set in a communication server, a router, a switch or a terminal device, etc., which are not listed here one by one. It can be understood that the above description on the communication device is applicable to the communication device in this application.

[0079] Optionally, the communication device in the embodiment of the present application may be a device that supports multiple WPAN standards such as IEEE802.15.4ab or subsequent versions currently under discussion.

[0080] In an embodiment of the present application, the above-mentioned communication device may include a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and a memory (also called main memory). The operating system may be any one or more computer operating systems that implement business processing through a process, 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, a word processing software, and an instant messaging software. In addition, the embodiment of the present application does not specifically limit the specific structure of the execution subject of the method provided in the embodiment of the present application, as long as it can communicate according to the method provided in the embodiment of the present application by running a program that records the code of the method provided in the embodiment of the present application.

[0081] For example, see Figure 1 , Figure 1 Schematic diagram of a wireless communication system provided by an embodiment of the present application. Figure 1 As shown, the wireless communication system is a star topology structure, in which a central control node (such as Figure 1 A PAN coordinator in a PAN can communicate data with one or more other devices. Figure 2 , Figure 2 is another structural diagram of the wireless communication system provided in the embodiment of the present application. Figure 2 As shown, the wireless communication system is a point-to-point topology structure, in which a central control node (such as Figure 2 The PAN coordinator in the PAN can communicate data with one or more other devices, and other different devices can also communicate data with each other. Figure 1 and Figure 2 In the present application, both the full-function device (FFD) and the reduced-function device (reduced-function device) can be understood as the communication device shown in this application. Among them, the full-function device and the reduced-function device are relative, such as the reduced-function device cannot be a PAN coordinator. For example, compared with the full-function device, the reduced-function device may not have coordination capabilities or the communication rate is lower than that of the full-function device. It can be understood that Figure 2 The PAN coordinator shown is an example only. Figure 2 The other three full-function devices shown can also serve as PAN coordinators, which are not shown one by one here. It can also be understood that the full-function devices and low-function devices shown in this application are only examples of communication devices, and any device that can implement the channel access method provided by this application belongs to the protection scope of this application.

[0082] A possible channel access method is Figure 3 As shown, Figure 3 1 is a flow chart of a channel access method provided by an embodiment of the present application. When there is a data message to be sent in a communication device operating in an unlicensed spectrum, the communication device can perform channel access. Figure 3 As shown, the channel access method may include:

[0083] (1) Initialize the backoff number (number of backoff, NB) counter and the backoff exponent (backoff exponent, BE), that is, NB = 0, and BE is initialized to the minimum value, that is, macMinBe. Among them, the backoff number NB counter is used to record the number of backoffs caused by the clear channel assignment (CCA) result being a busy channel. The backoff index BE is used to calculate the length of the backoff window (or backoff period). It can be understood that the backoff index in this application can also be called the backoff coefficient.

[0084] (2) Random backoff, such as randomly delaying to a backoff period (delay for random(2*BE or 2 BE )untilbackoff periods). The backoff method can be linear backoff (such as 2*BE) or exponential backoff (such as 2 BE ) or any one or both of them. Backoff means waiting for a random period of time. It can be understood that if it is a linear backoff, the length of the backoff window (or the length of the backoff period) is equal to 2*BE; if it is an exponential backoff, the length of the backoff window (or the length of the backoff period) is 2 BE .

[0085] (3) After the backoff is completed, a clear channel assignment (CCA) is performed, such as determining whether the channel is occupied (i.e., busy) through energy detection (or carrier sensing). If the result of CCA is that the channel is idle, that is, the channel is not occupied, then the data message can be sent (transmitted). If the result of CCA is that the channel is busy, that is, the channel is occupied, then the backoff index BE and NB counter are incremented, such as BE = min(BE+1, macMaxBe) and NB = NB+1. Among them, macMaxBe is the maximum value of the backoff index BE. min(x,y) means taking the minimum value of x and y. The same expressions below have the same meaning and will not be repeated one by one.

[0086] (4) Determine whether the value of the NB counter exceeds the preset threshold (macMaxCsmaBackoffs). If the value of the NB counter has not exceeded the preset threshold, that is, NB≤macMaxCsmaBackoffs, then back off again, that is, repeat steps (2) to (3). If the value of the NB counter exceeds the preset threshold, that is, NB>macMaxCsmaBackoffs, then decide whether to send (transmit) or discard (drop) the data message based on the judgment condition (that is, whether the parameter macBOEEndAction is equal to TxonEnd). If macBOEEndAction is equal to TxonEnd, then send the data message; if macBOEEndAction is not equal to TxonEnd, then discard the data message.

[0087] In this application, "dropping" the data message can be understood as not transmitting the data message in this channel access, and this application does not limit whether the data message will be transmitted in the next channel access. Similar expressions below have similar meanings and will not be described in detail one by one.

[0088] Understandably, Figure 3 "Y" means "yes" and "N" means "no".

[0089] Optionally, the minimum value of the backoff index BE (ie, macMinBe), the maximum value of the backoff index BE (ie, macMaxBe), the preset threshold (ie, macMaxCsmaBackoffs), macBOEEndAction, and TxonEnd are all medium access control (MAC) layer configuration parameters, which are usually configured by the upper layer.

[0090] It is understandable that the purpose of judging whether macBOEEndAction is equal to TxonEnd is to choose whether to send or discard directly when the result of long-term carrier sensing is that the channel is busy and cannot be sent. Generally speaking, it is more reasonable to choose to discard, because the result of carrier sensing is that the channel is busy, which means that other users are sending. If you send directly, it may increase conflicts and deteriorate performance.

[0091] By the above Figure 3It can be seen from the channel access method shown that the avoidance of conflicts (or collisions) depends on the result of energy detection (or carrier sensing). If the result of energy detection (or carrier sensing) is that the channel is busy, the backoff time is increased (such as the backoff index BE is increased); if the result of energy detection (or carrier sensing) is that the channel is idle, a wireless frame is sent. However, in the scenario where there are hidden terminals, conflicts (or collisions) may still occur even if the result of energy detection (or carrier sensing) is that the channel is idle.

[0092] See also Figure 4 , Figure 4 Schematic diagram of a scenario in which a hidden terminal exists provided by an embodiment of the present application. Figure 4 As shown in the figure, the scenario includes initiator 1 (Initiator1), initiator 2 (Initiator2), tag 1 and tag 2. The coverage of Initiator1 partially overlaps with the coverage of Initiator2, and tag 1 and tag 2 are located in this overlapping area; Initiator1 is outside the coverage of Initiator2, and for Initiator2, Initiator1 is a hidden terminal; Initiator2 is outside the coverage of Initiator1, and for Initiator1, Initiator2 is a hidden terminal. Assuming that Initiator1 wants to send information to tag 1 through the first link, and Initiator2 wants to send information to tag 2 through the second link, then Initiator1 and Initiator2 access the channel respectively. However, since Initiator2 is outside the coverage of Initiator1, when Initiator1 determines whether the channel is idle through energy detection (or carrier sensing), it can only detect whether tag 1 and tag 2 have sending behavior (that is, whether they occupy the channel). Similarly, since Initiator1 is outside the coverage of Initiator2, Initiator2 determines whether the channel is idle through energy detection (or carrier sensing), and can only detect whether Tag 1 and Tag 2 have any transmission behavior (i.e., whether they occupy the channel). If neither Tag 1 nor Tag 2 has any transmission behavior (i.e., not occupying the channel), the energy detection (or carrier sensing) result of Initiator1 is that the channel is idle, and the energy detection (or carrier sensing) result of Initiator2 is also that the channel is idle. Then, it is very likely that while Initiator1 is sending information to Tag 1, Initiator2 is also sending information to Tag 2, resulting in a collision. In other words, a collision will occur when the first link and the second link are sent at the same time.

[0093] In view of this, the embodiment of the present application provides another channel access method, which can be used in a scenario where there is a hidden terminal (such as the aforementioned Figure 4In the scenario shown in the figure) or other scenarios where conflicts may occur, conflicts or collisions are reduced and the performance of channel access is improved.

[0094] The technical solution provided by this application will be described in detail below with reference to more drawings.

[0095] In this application, unless otherwise specified, the same or similar parts between various embodiments or implementations can refer to each other. In each embodiment of this application, and each implementation method / implementation method / implementation method in each embodiment, if there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments and each implementation method / implementation method / implementation method in each embodiment are consistent and can be referenced to each other, and the technical features in different embodiments and each implementation method / implementation method / implementation method in each embodiment can be combined to form new embodiments, implementation methods, implementation methods, or implementation methods according to their inherent logical relationships. The implementation methods of this application described below do not constitute a limitation on the scope of protection of this application. It should be understood that the order of the following embodiments does not represent the degree of importance.

[0096] The communication device in the present application can support the 802.15.4ab standard or the next generation standard of 802.15.4ab, and can also 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 can also support WLAN standards of the 802.11 family such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11a, and 802.11be next generation.

[0097] See also Figure 5 , Figure 5 is another flow chart of the channel access method provided in the embodiment of the present application. Figure 4 In the scenario where there is a hidden terminal, the communication device involved in the method may be the aforementioned Figure 4 Initiator1 or Initiator2 in. Figure 5 As shown, the channel access method includes but is not limited to the following steps:

[0098] S101, the communication device sends a first wireless frame.

[0099] Optionally, the communication device of an embodiment of the present application uses an unlicensed spectrum for communication, and the communication device can perform channel access before sending the first radio frame. During the channel access process, if the result of the idle channel assessment (CCA) is idle, the communication device sends the first radio frame. Alternatively, when the value of the backoff number (NB) counter exceeds a preset threshold, the communication device decides to send according to the judgment condition (such as when the parameter macBOEEndAction is equal to TxonEnd), and then sends the first radio frame. Alternatively, in other cases, the communication device sends the first radio frame. The embodiment of the present application does not limit the conditions for the communication device to send the first radio frame.

[0100] Optionally, the first wireless frame may be a wireless frame in the 802.15 series of protocols or a wireless frame in the 802.11 series of protocols, 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 feedback a corresponding response frame, such as an acknowledgment (ACK) frame or a block acknowledgment (BA), etc., so that the communication device sending the first wireless frame can confirm that the other party has correctly received the first wireless frame.

[0101] S102, if the communication device does not receive a response frame to the first wireless frame after sending the first wireless frame, the communication device increases the value of the first backoff index and backs off according to the increased value of the first backoff index. After the backoff is completed, the communication device performs an idle channel assessment. If the result of the idle channel assessment is that the channel is idle, the communication device sends the first wireless frame. If the result of the idle channel assessment is that the channel is busy, the communication device increases the value of the second backoff index and backs off again.

[0102] For example, if the communication device does not receive a response frame to the first wireless frame after sending the first wireless frame, it can also be understood that the communication device determines that it does not receive a response frame to the first wireless frame after sending the first wireless frame.

[0103] Optionally, the channel access method further includes:

[0104] S103, if the communication device receives a response frame to the first wireless frame after sending the first wireless frame, the communication device sets the first backoff index to the minimum value of the first backoff index, and backs off according to the minimum value of the second backoff index. After the backoff is completed, the communication device performs an idle channel assessment. If the result of the idle channel assessment is that the channel is idle, the communication device sends a second wireless frame. If the result of the idle channel assessment is that the channel is busy, the communication device increases the value of the second backoff index and backs off again.

[0105] For example, if the communication device receives a response frame to the first wireless frame after sending the first wireless frame, it can also be understood that the communication device determines that the response frame to the first wireless frame is received after sending the first wireless frame.

[0106] Optionally, after the communication device sends the first wireless frame, it can detect whether a response frame to the first wireless frame is received within a preset time. The preset time can be a time specified by a standard protocol, such as a short interframe space (SIFS); the preset time can also be determined by negotiation between the two communicating parties, or the preset time can also be pre-configured by a central control node (such as a PAN coordinator or AP), which is not limited in the embodiments of the present application.

[0107] If the communication device does not receive a response frame for the first radio frame within a preset time after sending the first radio frame, it means that the first radio frame fails to be sent (or a conflict / collision occurs in this transmission), then the communication device can increase the value of the first backoff index and back off according to the increased value of the first backoff index. The first backoff index can be used to reflect the backoff caused by the conflict. For ease of description below, BF is used to represent the first backoff index. Of course, other methods can also be used to represent the first backoff coefficient. For example, in order to distinguish it from the second backoff coefficient, the first backoff coefficient can also be represented by BE′, or BE2, etc. Exemplarily, if the value of the increased first backoff index is less than or equal to the maximum value of the first backoff index, the communication device can back off according to the increased value of the first backoff index; if the value of the increased first backoff index is greater than the maximum value of the first backoff index, the communication device can back off according to the maximum value of the first backoff index. In other words, the communication device backs off according to the value of the first backoff index, and the value of the first backoff index (BF) satisfies BF=min(BF+1,macMaxBF), where macMaxBF represents the maximum value of the first backoff index. After the backoff is completed, the communication device can perform CCA. If the result of CCA is that the channel is idle, the communication device sends the first radio frame or other radio frames. If the result of CCA is that the channel is busy, the communication device increases the value of the second backoff index and backs off again. The second backoff index can be used to reflect the backoff caused by the CCA result being that the channel is busy. For ease of description below, BE is used to represent the second backoff index. Exemplarily, when the result of CCA is that the channel is busy, the communication device increases the value of the second backoff index. If the value of the increased second backoff index is less than or equal to the maximum value of the second backoff index, the communication device can back off again according to the value of the increased second backoff index; if the value of the increased second backoff index is greater than the maximum value of the second backoff index, the communication device can back off again according to the maximum value of the second backoff index. In other words, when the result of CCA is that the channel is busy, the communication device backs off again according to the value of the second backoff index, and 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.

[0108] Optionally, if the communication device receives a response frame to the first radio frame within a preset time after sending the first radio frame, indicating that the first radio frame is sent successfully (or that no conflict / collision occurs in this transmission), the communication device sets the first backoff index (BF) to the minimum value of the first backoff index, and backs off according to the minimum value of the second backoff index (BE). After the backoff is completed, the communication device can perform CCA. If the result of the CCA is that the channel is idle, the communication device sends a second radio frame. If the result of the CCA is that the channel is busy, the communication device increases the value of the second backoff index and backs off again. Among them, the second radio frame may be the same as the first radio frame, or it may be different. The second radio frame may also be a radio frame with a response mechanism.

[0109] Optionally, there may be multiple backoff methods, such as linear backoff, exponential backoff, or other backoff methods (such as any monotonically increasing function backoff), etc. The embodiments of the present application do not limit the specific backoff methods. 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 When other backoff methods are used, the length of the backoff window may be f(BF) or f(BE), where f(x) represents a monotonically increasing function.

[0110] Optionally, the first backoff index and the second backoff index may be different or the same. The following specifically describes the channel access process when the first backoff index and the second backoff index are different and the channel access process when the first backoff index and the second backoff index are the same with examples.

[0111] Implementation method 1: the first backoff index and the second backoff index are different.

[0112] In a possible implementation, backing off according to the increased value of the first backoff index includes: the communication device assigns the increased value of the first backoff index to the second backoff index, and then backing off according to the value of the second backoff index. In other words, the value of the first backoff index (BF) affects the value of the second backoff index (BE).

[0113] For example, see Figure 6 , Figure 6 This is a schematic diagram of the channel access process provided by the embodiment of the present application. It can be understood that Figure 6 "Y" in "Yes" means "yes", and "N" means "no". When there are wireless frames to be sent in the communication device, the communication device can enter the channel access process. Figure 6 As shown, the channel access process includes:

[0114] 1) Initialize the backoff count (NB) counter, that is, NB=0.

[0115] 2) Determine whether the last transmission was successful, that is, whether the parameter PacketSuccess (data packet success mark, or data packet sending success mark, etc.) is equal to 1. The parameter PacketSuccess can be used to indicate whether the last transmission was successful or not, or to indicate whether a response frame for a sent wireless frame has been received. If the parameter PacketSuccess is equal to 1, it means that the last transmission was successful; if the parameter PacketSuccess is not equal to 1, it means that the last transmission failed. Specifically, taking the last transmission of the first wireless frame as an example, if the response frame corresponding to the first wireless frame is received within the preset time, it means that the transmission is successful, and the parameter PacketSuccess can be set to 1; if the response frame corresponding to the first wireless frame is not received within the preset time, it means that the transmission failed, and the parameter PacketSuccess can be set to 0.

[0116] 3) If the last transmission was successful, that is, the parameter PacketSuccess is equal to 1, then initialize the first backoff index (BF) and the second backoff index (BE), such as BF = macMinBF, BE = macMinBe. Among them, macMinBF is the minimum value of the first backoff index, and macMinBe is the minimum value of the second backoff index. If the last transmission failed, that is, the parameter PacketSuccess is not equal to 1, then execute BF = min(BF+1, macMaxBF) and assign BF to BE, that is, BE = BF. Among them, macMaxBF is the maximum value of the first backoff index.

[0117] 4) Random backoff, such as random delay to backoff period (delay for random(2*BE or 2 BE )untilbackoff periods). The length of the backoff window (or the length of the backoff period) is 2*BE or 2 BE .

[0118] 5) After the backoff is executed, CCA is executed. If the result of CCA is that the channel is idle, that is, the channel is not occupied, the wireless frame can be transmitted. If the result of CCA is that the channel is busy, that is, the channel is occupied, the second backoff index (BE) and the backoff number (NB) counter are incremented, such as BE = min (BE + 1, macMaxBe) and NB = NB + 1. Among them, macMaxBe is the maximum value of the second backoff index.

[0119] 6) Determine whether the value of the backoff count (NB) counter exceeds the preset threshold (macMaxCsmaBackoffs). If the value of the NB counter has not exceeded the preset threshold, that is, NB≤macMaxCsmaBackoffs, then back off again, that is, repeat steps 4) to 5). If the value of the NB counter exceeds the preset threshold, that is, NB>macMaxCsmaBackoffs, decide whether to send (transmit) or discard (drop) the wireless frame according to the judgment condition (that is, whether the parameter macBOEEndAction is equal to TxonEnd). If macBOEEndAction is equal to TxonEnd, the wireless frame is sent; if macBOEEndAction is not equal to TxonEnd, the wireless frame is discarded.

[0120] 7) After sending the wireless frame, determine whether a response frame (such as ACK) is received for the wireless frame. If a response frame for the wireless frame is received within the preset time, the parameter PacketSuccess is set to 1; if no response frame for the wireless frame is received within the preset time, the parameter PacketSuccess is set to 0. It can be understood that whether the parameter PacketSuccess is set to 1 when a response frame is received or the parameter PacketSuccess is set to 1 when no response frame is received is not limited in the embodiments of the present application, and this is only an example. In actual applications, the parameter PacketSuccess may be set to 0 when a response frame is received, and the parameter PacketSuccess may be set to 1 when no response frame is received; accordingly, step 2) is to determine whether the parameter PacketSuccess is equal to 0.

[0121] Optionally, the maximum value macMaxBe of the second backoff index and the maximum value macMaxBF of the first backoff index can be set to the same value or different values. The minimum value macMinBF of the first backoff index and the minimum value macMinBe of the second backoff index can be set to the same value or different values.

[0122] In the embodiment of the present application, when a conflict occurs (i.e., no response frame is received after sending), the backoff window is increased by increasing the value of BF. In the scenario where a hidden terminal exists, the conflict or collision can be reduced and the performance of channel access can be improved. In addition, the embodiment of the present application assigns the value of BF to BE to ensure the continuity of the backoff window, which can prevent the backoff window from increasing due to a sending conflict, but the backoff window becomes smaller after CCA is performed.

[0123] In another possible implementation, the first backoff index and the second backoff index are independent of each other, that is, the value of the first backoff index (BF) will not affect the value of the second backoff index (BE).

[0124] For example, see Figure 7 , Figure 7 This is another schematic diagram of the channel access process provided by the embodiment of the present application. It can be understood that Figure 7 "Y" in "Yes" means "yes", and "N" means "no". When there are wireless frames to be sent in the communication device, the communication device can enter the channel access process. Figure 7 As shown, the channel access process includes:

[0125] 1) Initialize the backoff count (NB) counter and the second backoff index (BE), that is, NB = 0, BE = macMinBF, where macMinBe is the minimum value of the second backoff index.

[0126] 2) Determine whether the last transmission was successful, that is, whether the parameter PacketSuccess is equal to 1. If the parameter PacketSuccess is equal to 1, it means that the last transmission was successful; if the parameter PacketSuccess is not equal to 1, it means that the last transmission failed. Specifically, taking the last transmission as sending the first wireless frame as an example, if the response frame corresponding to the first wireless frame is received within the preset time, it means that the transmission is successful, and the parameter PacketSuccess can be set to 1; if the response frame corresponding to the first wireless frame is not received within the preset time, it means that the transmission failed, and the parameter PacketSuccess can be set to 0.

[0127] 3) If the last transmission was successful, that is, the parameter PacketSuccess is equal to 1, then the first backoff index (BF) is initialized, such as BF = macMinBF. Where macMinBF is the minimum value of the first backoff index. After initializing the first backoff index (BF), a random backoff is performed according to the value of the second backoff index (BE), that is, a random delay to the backoff period (delay forrandom (2*BE or 2 BE )until backoff periods), the length of the backoff window (or the length of the backoff period) is 2*BE or 2 BE .

[0128] 4) If the last transmission failed, that is, the parameter PacketSuccess is not equal to 1, then execute BF=min(BF+1,macMaxBF) and then perform a random backoff according to the value of the first backoff index (BF), that is, randomly delay to the backoff period (delay forrandom(2*BF or 2 BF )until backoff periods), the length of the backoff window (or the length of the backoff period) is 2*BF or 2 BF. Where macMaxBF is the maximum value of the first backoff index.

[0129] 5) After the backoff is executed, CCA is executed. If the result of CCA is that the channel is idle, that is, the channel is not occupied, the wireless frame can be transmitted. If the result of CCA is that the channel is busy, that is, the channel is occupied, the second backoff index (BE) and the backoff number (NB) counter are incremented, such as BE = min (BE + 1, macMaxBe) and NB = NB + 1. Among them, macMaxBe is the maximum value of the second backoff index.

[0130] 6) Determine whether the value of the backoff count (NB) counter exceeds the preset threshold (macMaxCsmaBackoffs). If the value of the NB counter has not exceeded the preset threshold, that is, NB≤macMaxCsmaBackoffs, then back off again, that is, repeat steps 4) to 5). If the value of the NB counter exceeds the preset threshold, that is, NB>macMaxCsmaBackoffs, decide whether to send (transmit) or discard (drop) the wireless frame according to the judgment condition (that is, whether the parameter macBOEEndAction is equal to TxonEnd). If macBOEEndAction is equal to TxonEnd, the wireless frame is sent; if macBOEEndAction is not equal to TxonEnd, the wireless frame is discarded.

[0131] 7) After sending the wireless frame, determine whether a response frame (such as ACK) is received for the wireless frame. If a response frame is received for the wireless frame within a preset time, the parameter PacketSuccess is set to 1; if no response frame is received for the wireless frame within a preset time, the parameter PacketSuccess is set to 0. It can be understood that whether the parameter PacketSuccess is set to 1 when a response frame is received or the parameter PacketSuccess is set to 1 when no response frame is received is not limited in the embodiments of the present application, and this is only an example.

[0132] Optionally, the maximum value macMaxBe of the second backoff index and the maximum value macMaxBF of the first backoff index can be set to the same value or different values. The minimum value macMinBF of the first backoff index and the minimum value macMinBe of the second backoff index can be set to the same value or different values.

[0133] In the embodiment of the present application, when a conflict occurs (i.e., no response frame is received after sending), the value of BF is increased to increase the backoff window, thereby reducing conflicts or collisions and improving the performance of channel access in the scenario where hidden terminals exist; and the embodiment of the present application separates the backoff caused by the conflict and the backoff caused by the CCA result being a busy channel, which can ensure the independence of the two backoff mechanisms and reduce the delay in scenarios with more conflicts.

[0134] Optional, above Figure 6 and Figure 7 In the example, at least one of macMinBF, macMinBe, macMaxBe or macMaxBF may be predefined or preconfigured. In one example, at least one of macMinBF, macMinBe, macMaxBe or macMaxBF may be interactively configured by the communicating parties through 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 to other nodes by a central control node (such as a full-function device) through a wireless broadcast frame. Exemplarily, the communication device may receive configuration parameters from the central control node, and the configuration parameters include one or more of the following: macMinBF, macMinBe, macMaxBe or macMaxBF. The configuration parameters may be carried in a wireless broadcast frame.

[0135] Implementation method 2: the first backoff index and the second backoff index are the same.

[0136] When the first backoff index and the second backoff index are the same, the second backoff index (BE) is used to reflect both the backoff caused by the conflict and the backoff caused by the CCA result that the channel is busy.

[0137] For example, see Figure 8 , Figure 8 This is another schematic diagram of the channel access process provided by the embodiment of the present application. It can be understood that Figure 8 "Y" in "Yes" means "yes", and "N" means "no". When there are wireless frames to be sent in the communication device, the communication device can enter the channel access process. Figure 8 As shown, the channel access process includes:

[0138] 1) Initialize the backoff count (NB) counter, that is, NB=0.

[0139] 2) Determine whether the last transmission was successful, that is, whether the parameter PacketSuccess is equal to 1. If the parameter PacketSuccess is equal to 1, it means that the last transmission was successful; if the parameter PacketSuccess is not equal to 1, it means that the last transmission failed. Specifically, taking the last transmission as sending the first wireless frame as an example, if the response frame corresponding to the first wireless frame is received within the preset time, it means that the transmission is successful, and the parameter PacketSuccess can be set to 1; if the response frame corresponding to the first wireless frame is not received within the preset time, it means that the transmission failed, and the parameter PacketSuccess can be set to 0.

[0140] 3) If the last transmission was successful, that is, the parameter PacketSuccess is equal to 1, then initialize the second backoff index (BE), such as BE = macMinBe. Where macMinBe is the minimum value of the second backoff index. If the last transmission failed, that is, the parameter PacketSuccess is not equal to 1, then increase the value of the second backoff index, such as executing BE = min (BE + 1, macMaxBe).

[0141] 4) Random backoff, such as random delay to backoff period (delay for random(2*BE or 2 BE )untilbackoff periods). The length of the backoff window (or the length of the backoff period) is 2*BE or 2 BE .

[0142] 5) After the backoff is executed, CCA is executed. If the result of CCA is that the channel is idle, that is, the channel is not occupied, the wireless frame can be transmitted. If the result of CCA is that the channel is busy, that is, the channel is occupied, the second backoff index (BE) and the backoff number (NB) counter are incremented, such as BE = min (BE + 1, macMaxBe) and NB = NB + 1. Among them, macMaxBe is the maximum value of the second backoff index.

[0143] 6) Determine whether the value of the backoff count (NB) counter exceeds the preset threshold (macMaxCsmaBackoffs). If the value of the NB counter has not exceeded the preset threshold, that is, NB≤macMaxCsmaBackoffs, then back off again, that is, repeat steps 4) to 5). If the value of the NB counter exceeds the preset threshold, that is, NB>macMaxCsmaBackoffs, decide whether to send (transmit) or discard (drop) the wireless frame according to the judgment condition (that is, whether the parameter macBOEEndAction is equal to TxonEnd). If macBOEEndAction is equal to TxonEnd, the wireless frame is sent; if macBOEEndAction is not equal to TxonEnd, the wireless frame is discarded.

[0144] 7) After sending the wireless frame, determine whether a response frame (such as ACK) is received for the wireless frame. If a response frame is received for the wireless frame within a preset time, the parameter PacketSuccess is set to 1; if no response frame is received for the wireless frame within a preset time, the parameter PacketSuccess is set to 0. It can be understood that whether the parameter PacketSuccess is set to 1 when a response frame is received or the parameter PacketSuccess is set to 1 when no response frame is received is not limited in the embodiments of the present application, and this is only an example.

[0145] Optionally, the minimum value macMinBe of the second backoff index and the maximum value macMaxBe of the second backoff index are both MAC layer configuration parameters, which are usually configured by an upper layer.

[0146] When a conflict occurs (i.e., no response frame is received after sending), the embodiment of the present application increases the value of BE to increase the backoff window, thereby reducing conflicts or collisions and improving the performance of channel access in scenarios where hidden terminals exist; and the embodiment of the present application does not introduce a new backoff index, and its implementation is simple, with few parameters and low complexity.

[0147] It is understandable that in the above Figures 6 to 8In the channel access process shown, the backoff number (NB) counter is used to record the number of backoffs caused by the CCA result being a busy channel. In some possible implementations, a new counter may be used to record the number of backoffs caused by conflicts. For ease of description, this new counter may be referred to as a number of collisions (NC) counter or a first counter, and the name of the new counter is not limited in this application. When the communication device receives a response frame to the first wireless frame within a preset time after sending the first wireless frame, that is, when the transmission is successful, the communication device sets the NC counter to 0. When the communication device does not receive a response frame to the first wireless frame within a preset time after sending the first wireless frame, that is, when the transmission fails, the communication device increases the value of the NC counter. In combination with the aforementioned Figure 6 , Figure 7 as well as Figure 8 For example, in any of the diagrams, after the parameter PacketSuccess is set to 1 in step 7), the value of the NC counter can be set to 0; after the parameter PacketSuccess is set to 0, the value of the NC counter can be increased, such as NC=NC+1.

[0148] Optionally, when the value of the NC counter is greater than a first preset threshold, or when the value of the NB counter is greater than a second preset threshold (ie, macMaxCsmaBackoffs), the communication device may reset the value of the NC counter to 0.

[0149] The embodiment of the present application adopts a new counter to record the number of backoffs caused by conflicts, which is more flexible and does not affect the recording of the NB counter. It can be understood that the NB counter can be used to control the maximum number of backoffs of a message, while the NC counter is used to control the number of times a message is sent to successfully sent. For different scenarios, the maximum value of the NB counter and the maximum value of the NC counter can be set to different values ​​according to their different meanings, so that the NB counter and the NC counter can be counted separately more flexibly.

[0150] In some other possible implementations, the NB counter may be used to record all backoff times, that is, the NB counter not only records the backoff times due to the CCA result of channel busy, but also records the backoff times due to conflicts. When the communication device receives a response frame to the first wireless frame within a preset time after sending the first wireless frame, that is, when the sending is successful, the communication device sets the NB counter to 0. When the communication device does not receive a response frame to the first wireless frame within a preset time after sending the first wireless frame, that is, when the sending fails, the communication device increases the value of the NB counter, such as NB=NB+1, and the communication device does not initialize the NB counter the next time the channel is accessed. Combined with the aforementioned Figure 6 , Figure 7 as well as Figure 8 For example, in any of the diagrams, after the parameter PacketSuccess is set to 1 in step 7), the value of the NB counter can be set to 0; after the parameter PacketSuccess is set to 0, the value of the NB counter can be increased, such as NB=NB+1, and the step of initializing the NB counter can be skipped during the next channel access.

[0151] The embodiment of the present application adopts an NB counter to record all backoff times, which can uniformly maintain the life cycle of the message and control the maximum delay.

[0152] In order to better illustrate the beneficial effects of the channel access method provided in the embodiment of the present application, the simulation results of the throughput rate and the probability of successful access in a hidden terminal scenario are given as examples below.

[0153] See also Fig. 9 , Fig. 9 It is a simulation schematic diagram of the beneficial effects provided by the embodiments of the present application. Fig. 9 The following figure shows the schematic diagram of the change of the probability of successful access with delay and the change of throughput with time after the channel access method of the embodiment of the present application is adopted. The unit of the horizontal axis is seconds (s), and delay represents the time from the message entering the sending queue to the successful sending. Link-0 represents the aforementioned Figure 4 The first link in the scenario shown, Link-1, represents the aforementioned Figure 4 The second link in the scenario shown, Total represents the total throughput of the first link and the second link. Fig. 9 It can be seen that after adopting the channel access method of the embodiment of the present application, the total throughput is significantly improved. In addition, the initiator on the first link and the initiator on the second link can successfully access the channel and send messages in a shorter time (approximately 0.02s), thereby reducing the sending delay.

[0154] Therefore, the channel access method provided in the embodiment of the present application increases the backoff window and performs backoff when a conflict / collision occurs, which can be used in a scenario where there is a hidden terminal (such as the aforementioned Figure 4 In the scenario shown in the figure, conflicts or collisions are reduced and the performance of channel access is improved.

[0155] The above content elaborates on the method provided by the present application. In order to facilitate the implementation of the above scheme of the embodiment of the present application, the embodiment of the present application also provides corresponding devices or equipment.

[0156] The present application divides the functional modules of the communication device according to the above method embodiment. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or software functional modules. It should be noted that the division of modules in the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. Figures 10 to 12 The communication device according to the embodiment of the present application is described in detail.

[0157] See also Fig.10 , Fig.10 is a schematic diagram of a structure of a communication device provided in an embodiment of the present application. Fig.10 As shown, the communication device includes a transceiver unit 10 and a processing unit 20.

[0158] The transceiver unit 10 is used to send a first radio frame; the processing unit 20 is used to increase the value of the first backoff index if no response frame is received for the first radio frame after the first radio frame is sent, and perform backoff according to the increased value of the first backoff index, and perform idle channel evaluation after the backoff is completed, and when the result of the idle channel evaluation is that the channel is busy, increase the value of the second backoff index and perform backoff again, and control the transceiver unit 10 to send the first radio frame when the result of the idle channel evaluation is that the channel is idle;

[0159] And / or; the processing unit 20 is also used to, when a response frame to the first wireless frame is received after sending the first wireless frame, set the first backoff index to the minimum value of the first backoff index, and back off according to the minimum value of the second backoff index, and perform idle channel evaluation after the backoff is completed, and when the result of the idle channel evaluation is that the channel is busy, increase the value of the second backoff index and back off again, and control the transceiver unit 10 to send the second wireless frame when the result of the idle channel evaluation is that the channel is idle.

[0160] In a possible implementation, the processing unit 20 is further configured to perform backoff according to the increased value of the first backoff index when the increased value of the first backoff index is less than or equal to the maximum value of the first backoff index.

[0161] In a possible implementation, the processing unit 20 is further configured to perform backoff according to the maximum value of the first backoff index when the increased value of the first backoff index is greater than the maximum value of the first backoff index.

[0162] In a possible implementation, the processing unit 20 is specifically configured to perform backoff according to a value of a second backoff index, where the value of the second backoff index is an increased value of the first backoff index.

[0163] In a possible implementation, the first backoff index is the same as the second backoff index.

[0164] In one possible implementation, the processing unit 20 is also used to: set the conflict count counter to 0 when a response frame to the first wireless frame is received after the first wireless frame is sent; and increase the value of the conflict count counter when no response frame to the first wireless frame is received after the first wireless frame is sent.

[0165] In a possible implementation, the conflict count counter is a backoff count counter, and the backoff count counter is used to record the number of backoffs.

[0166] In a possible implementation, the processing unit 20 is further configured to reset the conflict count counter to 0 when the incremented value of the conflict count counter is greater than a preset threshold.

[0167] In one possible implementation, the processing unit 20 is specifically used to: increase the value of the second backoff index; when the increased value of the second backoff index is less than or equal to the maximum value of the second backoff index, re-backoff according to the increased value of the second backoff index; when the increased value of the second backoff index is greater than the maximum value of the second backoff index, re-backoff according to the maximum value of the second backoff index.

[0168] In a possible implementation, at least one of the minimum value of the first backoff index, the minimum value of the second backoff index, the maximum value of the first backoff index, and the maximum value of the second backoff index is predefined or preconfigured.

[0169] In a possible implementation, the transceiver unit 10 is also used to receive configuration parameters from the central control node, and the configuration parameters include one or more of the following: the minimum value of the first backoff index, the minimum value of the second backoff index, the maximum value of the first backoff index, or the maximum value of the second backoff index.

[0170] In a possible implementation manner, the configuration parameter is carried in a wireless broadcast frame.

[0171] It can be understood that the specific description of the transceiver unit and the processing unit shown in the embodiment of the present application is only an example. For the specific functions or execution steps of the transceiver unit and the processing unit, reference can be made to the above-mentioned method embodiment, which will not be described in detail here.

[0172] The above describes the communication device of the embodiment of the present application, and the following describes possible product forms of the communication device. It should be understood that any device having the above Fig.10 Any form of product with the functions of the communication device described above falls within the protection scope of the embodiments of the present application. It should also be understood that the following description is only an example and does not limit the product form of the communication device of the embodiments of the present application to this.

[0173] In one possible implementation, Fig.10 In the communication device shown, the processing unit 20 may be one or more processors, the transceiver unit 10 may be a transceiver, or the transceiver unit 10 may also be a sending unit and a receiving unit, the sending unit may be a transmitter, the receiving unit may be a receiver, and the sending unit and the receiving unit are integrated into one device, such as a transceiver. In the embodiment of the present application, the processor and the transceiver may be coupled, etc., and the embodiment of the present application does not limit the connection mode of the processor and the transceiver. In the process of executing the above method, the process of sending information in the above method can be understood as the process of outputting the above information by the processor. When outputting the above information, the processor outputs the above information to the transceiver so that it is transmitted by the transceiver. After the above information is output by the processor, it may also need to be processed in other ways before it reaches the transceiver. Similarly, the process of receiving information in the above method can be understood as the process of the processor receiving the input information. When the processor receives the input information, the transceiver receives the above information and inputs it into the processor. Furthermore, after the transceiver receives the above information, the above information may need to be processed in other ways before it is input into the processor.

[0174] See also Fig.11 , Fig.11 It is a schematic diagram of the structure of the communication device 1000 provided in an embodiment of the present application. Fig.11 Only the main components of the communication device 1000 are shown. In addition to the processor 1001 and the transceiver 1002, the communication device may further include a memory 1003 and an input and output device (not shown in the figure).

[0175] The processor 1001 is mainly used to process the communication protocol and communication data, and to control the entire communication device, execute the software program, and process the data of the software program. The memory 1003 is mainly used to store the software program and data. The transceiver 1002 may include a control circuit and an antenna. The control circuit is mainly used to convert the baseband signal and the radio frequency signal and process the radio frequency signal. The antenna is mainly used to send and receive radio frequency signals in the form of electromagnetic waves. The input and output devices, such as a touch screen, a display screen, a keyboard, etc., are mainly used to receive data input by the user and output data to the user.

[0176] When the communication device is turned 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 sent wirelessly, the processor 1001 performs baseband processing on the data to be sent, and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then sends the radio frequency signal outward in the form of electromagnetic waves through the antenna. When data is sent to the communication device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio 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.

[0177] In another implementation, the RF circuit and antenna may be arranged independently of the processor performing baseband processing. For example, in a distributed scenario, the RF circuit and antenna may be arranged remotely from the communication device.

[0178] The transceiver 1002 may include a receiver and a transmitter, wherein the receiver is used to perform a receiving function (or operation) and the transmitter is used to perform a transmitting function (or operation), and the transceiver is used to communicate with other devices / apparatuses through a transmission medium.

[0179] The processor 1001 , the transceiver 1002 , and the memory 1003 may be connected via a communication bus.

[0180] Exemplarily, the communication device 1000 may be used to perform the functions of the aforementioned method embodiment: the processor 1001 may be used to execute Figure 5 Steps S102 and S103 in, and / or other processes for performing the techniques described herein; the transceiver 1002 may be used to perform Figure 5 Step S101 in the process, and / or other processes for the technology described in this article.

[0181] Optionally, the processor 1001 may include a transceiver for implementing the receiving and sending functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing the receiving and sending functions may be separate or integrated. The above-mentioned transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or the above-mentioned transceiver circuit, interface, or interface circuit may be used for transmitting or delivering signals.

[0182] Optionally, the processor 1001 may store instructions, which may be computer programs. The computer programs run on the processor 1001, and the communication device 1000 may execute the method described in the above method embodiment. The computer program may be fixed in the processor 1001, in which case the processor 1001 may be implemented by hardware.

[0183] In one implementation, the communication device 1000 may include a circuit that can implement the functions of sending or receiving or communicating in the aforementioned method embodiment. The processor and transceiver described in the present application can be implemented in an integrated circuit (IC), an analog IC, a radio frequency integrated circuit (RFIC), a mixed signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc. The processor and transceiver can also be manufactured using various IC process technologies, such as complementary metal oxide semiconductor (CMOS), N-type metal oxide semiconductor (nMetal-oxide-semiconductor, NMOS), P-type metal oxide semiconductor (positive channel metal oxide semiconductor, PMOS), bipolar junction transistor (bipolar junction transistor, BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0184] It is understandable that the communication device shown in the embodiment of the present application may also have Fig.11 The embodiments of the present application do not limit the number of components and the like. The methods executed by the processor and transceiver shown above are only examples, and the specific steps executed by the processor and transceiver can refer to the introduction of the above method embodiments.

[0185] In another possible implementation, Fig.10 In the communication device shown, the processing unit 20 may be one or more logic circuits, and the transceiver unit 10 may be an input / output interface, or a communication interface, or an interface circuit, or 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, the receiving unit may be an input interface, and the sending unit and the receiving unit may be integrated into one unit, such as an input / output interface. Fig.12 , Fig.12 is another structural diagram of the communication device provided in the embodiment of the present application. Fig.12 As shown, Fig.12 The communication device shown includes a logic circuit 901 and an interface 902. That is, the processing unit 20 can be implemented by the logic circuit 901, and the transceiver unit 10 can be implemented by the interface 902. The logic circuit 901 can be a chip, a processing circuit, an integrated circuit or a system on chip (SoC) chip, etc., and the interface 902 can be a communication interface, an input / output interface, a pin, etc. For example, Fig.12 The above communication device is taken as an example of a chip, and the chip includes a logic circuit 901 and an interface 902 .

[0186] In the embodiment of the present application, the logic circuit and the interface may also be coupled to each other. The embodiment of the present application does not limit the specific connection method between the logic circuit and the interface.

[0187] Exemplarily, when the communication device is used to execute the method, function or step executed by the communication device in the aforementioned method embodiment, the interface 902 is used to output a first radio frame; the logic circuit 901 is used to increase the value of the first backoff index when no response frame for the first radio frame is received after sending the first radio frame, and back off according to the increased value of the first backoff index, and perform idle channel evaluation after the backoff is completed, when the result of the idle channel evaluation is that the channel is busy, increase the value of the second backoff index and back off again, and control the interface 902 to output the first radio frame when the result of the idle channel evaluation is that the channel is idle;

[0188] And / or; the logic circuit 901 is also used to, when a response frame to the first wireless frame is received after sending the first wireless frame, set the first backoff index to the minimum value of the first backoff index, and back off according to the minimum value of the second backoff index, and perform idle channel evaluation after the backoff is completed, and when the result of the idle channel evaluation is that the channel is busy, increase the value of the second backoff index and back off again, and the control interface 902 outputs the second wireless frame when the result of the idle channel evaluation is that the channel is idle.

[0189] It is understood that for the detailed description of the logic circuit 901 and the interface 902, reference can be made to Fig.10 The description of the processing unit and the transceiver unit shown will not be repeated here.

[0190] It can be understood that the communication device shown in the embodiment of the present application can implement the method provided in the embodiment of the present application in the form of hardware, or can implement the method provided in the embodiment of the present application in the form of software, etc., and the embodiment of the present application is not limited to this.

[0191] for Fig.12 The specific implementation methods of the various embodiments shown can also refer to the above embodiments, which will not be described in detail here.

[0192] The present application also provides a computer-readable storage medium, in which computer codes are stored. When the computer codes are executed on a computer, the computer executes the operations and / or processes performed by the communication device in the method provided by the present application.

[0193] The present application also provides a computer program, which is used to implement the operations and / or processing performed by the communication device in the method provided by the present application.

[0194] The present application also provides a computer program product, which includes a computer code or a computer program. When the computer code or the computer program runs on a computer, the operations and / or processing performed by the communication device in the method provided by the present application are executed.

[0195] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or it can be an electrical, mechanical or other form of connection.

[0196] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the technical effects of the solutions provided in the embodiments of the present application.

[0197] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0198] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or partly contributed to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a readable storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned readable storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0199] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A channel access method, characterized in that: include: The communication device sends a first wireless frame; If the communication device does not receive a response frame to the first radio frame after sending the first radio frame, the communication device increases the value of a first backoff index, and performs backoff according to the increased value of the first backoff index. After the backoff is completed, the communication device performs an idle channel assessment. If the result of the idle channel assessment is that the channel is idle, the communication device sends the first radio frame. If the result of the idle channel assessment is that the channel is busy, the communication device increases the value of a second backoff index and performs backoff again. And / or, if the communication device receives a response frame to the first wireless frame after sending the first wireless frame, the communication device sets the first backoff index to the minimum value of the first backoff index, and backs off according to the minimum value of the second backoff index. After the backoff is completed, the communication device performs an idle channel assessment. If the result of the idle channel assessment is that the channel is idle, the communication device sends a second wireless frame. If the result of the idle channel assessment is that the channel is busy, the communication device increases the value of the second backoff index and backs off again.

2. The method according to claim 1, characterized in that The method further comprises: If the increased value of the first backoff index is less than or equal to the maximum value of the first backoff index, the communication device performs backoff according to the increased value of the first backoff index.

3. The method according to claim 1, characterized in that The method further comprises: If the increased value of the first backoff index is greater than the maximum value of the first backoff index, the communication device backs off according to the maximum value of the first backoff index.

4. The method according to any one of claims 1 to 3, characterized in that The backing off according to the increased value of the first backoff index includes: Backoff is performed according to a value of a second backoff index, where the value of the second backoff index is the increased value of the first backoff index.

5. The method according to any one of claims 1 to 4, characterized in that The first backoff index and the second backoff index are the same.

6. The method according to any one of claims 1 to 5, characterized in that After the communication device sends the first wireless frame, the method further includes: When the communication device receives a response frame to the first radio frame after sending the first radio frame, the communication device sets a conflict count counter to 0; When the communication device does not receive a response frame to the first radio frame after sending the first radio frame, the communication device increases the value of the collision number counter.

7. The method according to claim 6, characterized in that The conflict count counter is a backoff count counter, and the backoff count counter is used to record the number of backoffs.

8. The method according to claim 6 or 7, characterized in that: The method further comprises: When the incremented value of the conflict count counter is greater than a preset threshold, the communication device resets the conflict count counter to 0.

9. The method according to any one of claims 1 to 8, characterized in that The communication device increases the value of the second backoff index and performs backoff again, including: The communication device increases the value of the second backoff index; 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 performs backoff again according to the increased value of the second backoff index; If the increased value of the second backoff index is greater than the maximum value of the second backoff index, the communication device performs backoff again according to the maximum value of the second backoff index.

10. The method according to any one of claims 1 to 9, characterized in that At least one of the minimum value of the first backoff index, the minimum value of the second backoff index, the maximum value of the first backoff index, and the maximum value of the second backoff index is predefined or preconfigured.

11. The method according to any one of claims 1 to 10, characterized in that Before the communication device sends the first wireless frame, the method further includes: The communication device receives configuration parameters from a central control node, where the configuration parameters include one or more of the following: a minimum value of the first backoff index, a minimum value of the second backoff index, a maximum value of the first backoff index, or a maximum value of the second backoff index.

12. The method according to claim 11, characterized in that The configuration parameters are carried in a wireless broadcast frame.

13. A communication device, characterized in that: including a processor and a memory; The memory is used to store instructions; The processor is configured to execute the instructions so that the method according to any one of claims 1 to 12 is performed.

14. A communication device, characterized in that: comprising a logic circuit and an interface, wherein the logic circuit and the interface are coupled; The interface is used to input and / or output code instructions, and the logic circuit is used to execute the code instructions so that the method according to any one of claims 1 to 12 is executed.

15. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program. When the computer program is executed, the method according to any one of claims 1 to 12 is executed.

16. A computer program product, characterized in that The computer program product comprises a computer program or a computer code, which enables the method according to any one of claims 1 to 12 to be executed when it is run on a computer.

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