CN114916085A

CN114916085A - Channel access method, device, equipment and storage medium

Info

Publication number: CN114916085A
Application number: CN202210394224.XA
Authority: CN
Inventors: 徐彦超; 余庆华; 王泷
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2022-04-14
Filing date: 2022-04-14
Publication date: 2022-08-16
Also published as: WO2023197782A1

Abstract

The application discloses a channel access method, a device, equipment and a storage medium, and relates to the technical field of communication. The method comprises the following steps: in case the channel state is idle and it is decided to restart the channel backoff access procedure, the following steps are performed: in the first channel backoff access process, obtaining a transmission opportunity but abandoning the transmission; executing a second channel backoff access process; and the first channel backoff access process is the last channel backoff access process of the second channel backoff access process. The above scheme provides a way to restart the execution of the channel backoff access procedure based on the channel being in an idle state.

Description

Channel access method, device, equipment and storage medium

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a channel access method, apparatus, device, and storage medium.

Background

When the wireless communication device uses a channel corresponding to the unlicensed spectrum, it needs to use a channel backoff access process to determine that the channel is in an idle state, so that the wireless communication device can use the channel, and a continuous IFS time channel in an IFS (Inter Frame Space) channel detection stage in the channel backoff access process is an idle starting reference point and is a time point when the last channel is busy.

However, the above scheme is not suitable for channel access in complex scenarios, such as channel access between different STAs (stations) in an MLD (Multiple link Device), and when STA1 expects that transmission on the channel will affect data interaction of STA2, STA1 needs to restart the channel backoff access procedure.

Disclosure of Invention

The embodiment of the application provides a channel access method, a device, equipment and a storage medium. The technical scheme is as follows:

according to an aspect of an embodiment of the present application, there is provided a channel access method, including:

in case the channel state is idle and it is decided to restart the channel backoff access procedure, the following steps are performed:

in the first channel backoff access process, obtaining a transmission opportunity but abandoning the transmission; executing a second channel backoff access process; and the first channel backoff access process is the last channel backoff access process of the second channel backoff access process.

According to an aspect of an embodiment of the present application, there is provided a channel access apparatus, including:

a processing module, configured to execute the following steps when the channel status is idle and it is decided to restart the channel backoff access procedure:

According to an aspect of an embodiment of the present application, there is provided a first wireless communication device comprising a processor;

a processor, configured to, in case that the channel status is idle and it is decided to restart the channel backoff access procedure, perform the following steps:

According to an aspect of the embodiments of the present application, there is provided a computer-readable storage medium, in which a computer program is stored, and the computer program is used for a processor to execute so as to implement the above channel access method.

According to an aspect of the embodiments of the present application, there is provided a chip, which includes a programmable logic circuit and/or program instructions, and when the chip is operated, is used for implementing the above channel access method.

According to an aspect of embodiments of the present application, there is provided a computer program product or a computer program, the computer program product or the computer program comprising computer instructions stored in a computer-readable storage medium, from which a processor reads and executes the computer instructions to implement the above-mentioned channel access method.

The technical scheme provided by the embodiment of the application can bring the following beneficial effects:

by performing the following steps in case the channel state is idle and it is decided to restart the channel backoff access procedure: in the first channel backoff access process, obtaining a transmission opportunity but abandoning the transmission; executing a second channel backoff access process; the first channel backoff access process is the last channel backoff access process of the second channel backoff access process, and a mode for restarting the channel backoff access process based on the fact that the channel is in an idle state is provided. The method and the device solve the defect that in the related technology, the continuous IFS time channel at the IFS channel detection stage in the channel backoff access process is an idle starting reference point and can only be the time point when the last channel is busy.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a diagram illustrating a channel backoff access procedure according to an embodiment of the present application;

fig. 2 is a diagram illustrating a channel backoff access procedure provided in another exemplary embodiment of the present application;

fig. 3 is a schematic diagram of an Enhanced Distributed Channel Access (EDCA) backoff provided in an exemplary embodiment of the present application;

fig. 4 is a schematic diagram of a wireless local area network provided by an exemplary embodiment of the present application;

FIG. 5 is a schematic illustration of multilink transmission or reception of data as provided by an exemplary embodiment of the present application;

FIG. 6 is a schematic diagram of a multilink packet interaction provided by an exemplary embodiment of the present application;

fig. 7 is a flowchart of a channel access method provided by an exemplary embodiment of the present application;

fig. 8 is a flowchart of a channel access method provided by another exemplary embodiment of the present application;

FIG. 9 is a schematic illustration of a multilink packet interaction provided by another exemplary embodiment of the present application;

FIG. 10 is a schematic illustration of a multilink packet interaction provided by another exemplary embodiment of the present application;

fig. 11 is a flowchart of a channel access method provided by another exemplary embodiment of the present application;

FIG. 12 is a schematic diagram of a multilink packet interaction provided by another exemplary embodiment of the present application;

FIG. 13 is a schematic illustration of a multilink packet interaction provided by another exemplary embodiment of the present application;

fig. 14 is a flowchart of a channel access method provided by another exemplary embodiment of the present application;

FIG. 15 is a schematic diagram of a multilink packet interaction provided by another exemplary embodiment of the present application;

fig. 16 is a block diagram of a channel access apparatus according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of a wireless communication device according to an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Channel backoff access procedure: in the related art, the Channel Backoff Access procedure at least includes DCF (Distributed Coordination Function) or EDCA (Enhanced Distributed Channel Access) Backoff, and the DCF and EDCA will be described below.

CSMA/CA (Carrier Sense Multiple Access with connectivity Avoidance) is the core mechanism of DCF and EDCA. Since the wireless channel has only one collision domain, a random access mechanism, namely CSMA/CA in the WiFi protocol, needs to be set to avoid collision problem caused by multiple wireless communication devices accessing the network at the same time.

DCF: fig. 1 shows that when the wireless communication device 1 and the wireless communication device 2 have data in succession, need to obtain transmission right and transmit on the channel, the wireless communication device 1 and the wireless communication device 2 first need to "wait" for DIFS (Distributed Inter-frame Spacing) time, and if the channel remains idle during the DIFS time, a backoff (backoff) procedure may be performed. It should be noted that the "waiting" procedure of DIFS is not a true waiting procedure, and the channel is monitored to be idle for a continuous IFS time in DIFS. The following description will be made in detail while describing EDCA.

If the wireless communication apparatus 1 and the wireless communication apparatus 2 enter the back-off (backoff) process, they first need to select a random number from a Contention Window (CW). In fig. 1, wireless communication device 1 selects 2, and wireless communication device 2 selects 8.

In the back-off process, the wireless communication device "listens" to the channel every slot (slot) that passes, and if the channel is idle, the value of the corresponding back-off counter is decremented by 1. After 3 slots, as in fig. 1, the back-off counter of wireless communication device 2 is decremented from 8 to 5, while wireless communication device 1 correspondingly decrements from 2 to 0.

When the back-off counter counts down to 0, the wireless communication device obtains the transmission right so that data can be transmitted. As shown in fig. 1, the wireless communication apparatus 1 obtains the transmission right and then transmits PACKET a (PACKET a) to the AP. After receiving the data, the AP checks the data by using a Cyclic Redundancy Check (CRC) mechanism, and if the data passes the Check, the AP feeds back an ACK acknowledgement Frame after a Short Inter-Frame Space (SIFS). This transmission is completed when the wireless communication device 1 successfully receives the ACK frame.

When this transmission is completed, the wireless communication device needs to monitor the channel as idle again for the continuous IFS time in the DIFS, and then restart the backoff procedure. If the wireless communication device has just finished transmitting data, when the back-off process starts, a random number needs to be selected from the contention window again for counting down. If the wireless communication device is not transmitting data, then the countdown continues directly from the last countdown result. As in fig. 1, the wireless communication device 2 does not obtain the transmission right, and then it directly performs the reciprocal numbers up to 4 based on the last 5 in the backoff process of the second time. The purpose of such design is to ensure fairness of network transmission.

EDCA: EDCA Backoff is a channel Backoff Access procedure enhanced on the basis of DCF, and selects an IFS and an initial random Backoff Slot value (Backoff Slot Count) according to the type of frame (frame) to be transmitted and/or AC (Access Code). Namely, the whole EDCA backoff process is divided into two parts: an IFS channel detection stage and a random backoff stage; if the channel is in an idle state (idle) in the stage of detecting the IFS channel, starting to continue detecting the channel in each backoff slot (backoff slot), and if the channel is in an idle state in the ith slot, subtracting 1 from the backoff slot (backoff slot count), and continuing to detect the channel in the (i + 1) th slot until the backoff slot value is reduced to 0.

Referring to fig. 2 in conjunction, the consecutive IFS time channels of the IFS channel detection phase are the starting reference point of being free, which is the point in time when the last channel busy ("channel busy" in fig. 2) ended.

As shown in fig. 2, starting from the basic time slice SIFS, PIFS + SIFS +1 slot, DIFS +2 slot, and AIFS + n slot. If n is larger, it means that more time is required to wait before accessing the channel each time, and thus the priority of the current wireless communication device is considered to be lower. In fig. 5, AIFS [ AC ] ═ SIFS +4 slot, and AIFS [ AC' ] ═ SIFS +5 slot.

Referring to fig. 3 in combination, fig. 3 illustrates the definition and corresponding processing of each time point (boundary) in the EDCA backoff procedure defined in the related art. In the EDCA backoff process shown in fig. 3, the AIFS duration is AIFS ═ aSIFSTime + AIFSN × (Slot time), where 1 SIFS duration is usually 16us or 10us, 1 Slot duration is 9us, the AIFSN value in fig. 3 is 2, and the number of randomly selected backoff slots is 1(CW ═ 1). In fig. 3, 1 SIFS time length is D1+ M1+ Rx/Tx, and 1 Slot time length is D2+ CCADel + M2+ Rx/Tx;

wherein, D1 ═ Delay1 (processing Delay 1), M1 ═ M2 ═ mac processing Delay, Rx/Tx ═ arxtxrnarountintime (a transceiving conversion time), D2 ═ D1+ aairrpropagationtime (an air interface propagation time), CCAdel ═ aacchannel estimation detection time) -D1;

in the EDCA Backoff procedure shown in fig. 3, the time points (Boundary) at which the channel busy condition of the current wireless network device needs to be detected are an AIFSN Slot Boundary (AIFSN Slot Boundary) and a Backoff Slot Boundary (Backoff Slot Boundary). In order to consider the actual processing delay, it can be seen that the time point at which the channel Busy determination is made is actually a time point which lasts for (SIFS duration +1 Slot duration-RxTxTurnaroundTime) and a time point which lasts for (SIFS duration +2 Slot duration-RxTxTurnaroundTime) from the last channel Busy (Busy medium) end time as the starting point.

It can be known that, with reference to fig. 1, fig. 2 and fig. 3, when a wireless network device intends to use a channel for data transmission, the wireless network device starts a channel backoff access process, and a reference point of a continuous channel idle time in the channel backoff access process is a time point when a last busy state ends. In addition, in the channel backoff access process, the wireless communication device continuously determines whether the channel to be used is in an idle state, and the wireless communication device can not obtain the channel use right until the channel backoff access process determines that the channel is in the idle state. That is, the reference point of the continuous channel idle time in the channel backoff access process is the time point at which the last busy state ends.

However, when the channel backoff access procedure is applied to a Multiple Link Device (MLD), the influence of data interaction between different STAs in the STA (Station) MLD (Multiple link Device) on different Links is also considered; or the influence of different APs in an AP (Access Point) MLD on data interaction on different links.

In these scenarios, it is necessary to consider how to start a channel backoff access procedure when a channel to be used is in an idle state.

A wireless local area network based on MLD will be described below. Fig. 4 is a block diagram of a wireless local area network provided by an exemplary embodiment of the present application. The wireless local area network may include: STA MLD 41 and AP MLD 42.

The STA MLD 41 includes one or more logical entities STA, and the STA may be a wireless communication chip, a wireless sensor, or a wireless communication terminal. For example, a mobile phone supporting a Wireless Fidelity (WiFi) communication function, a tablet computer supporting a WiFi communication function, a set-top box supporting a WiFi communication function, a smart television supporting a WiFi communication function, a smart wearable device supporting a WiFi communication function, a vehicle-mounted communication device supporting a WiFi communication function, and a computer supporting a WiFi communication function.

The AP MLD 42 includes one or more logical entities AP. The AP may be an access point through which a mobile user enters a wired network, and is mainly deployed in a home, a building, and a campus, and a typical coverage radius is several tens of meters to hundreds of meters, or certainly, may be deployed outdoors. The AP is equivalent to a bridge connected with a network and a wireless network, and mainly functions to connect various wireless network clients together and then access the wireless network to the ethernet. Specifically, the AP may be a terminal device or a network device with a WiFi chip.

In the embodiment of the application, a multilink is established between the STA MLD 41 and the AP MLD 42. An exemplary STA MLD 41 includes: STA1 and STA2, AP MLD 42 includes: AP1 and AP2, STA1 and STA2 interact with AP1 and AP2, respectively, i.e., AP1 and AP2 are peer logical entities of STA1 and STA2, respectively. Illustratively, link 1 exists between STA1 and AP1, link 2 exists between STA2 and AP2, STA1 receives data transmitted by AP1 over link 1, or AP1 receives data transmitted by STA1 over link 1; STA2 receives data transmitted by AP2 over link 2 or AP2 receives data transmitted by STA2 over link 2.

In the embodiment of the present application, both the STA MLD 41 and the AP MLD 42 support the 802.11 standard. It is to be understood that the STA MLD 41 and the AP MLD 42 in the embodiment of the present application may also support an evolved standard of the 802.11 standard, and may also support other communication standards. For example, 802.11be, etc. and later versions are supported.

It should be noted that the network architecture and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not constitute a limitation to the technical solution provided in the embodiment of the present application, and it is known by a person skilled in the art that the technical solution provided in the embodiment of the present application is also applicable to similar technical problems along with the evolution of the network architecture and the appearance of a new service scenario.

As shown in fig. 4, two interconnected devices STA MLD and AP MLD supporting multi-link function (Multiple Links Operation) are defined. The STA MLD and the AP MLD which establish the multilinks with each other can utilize the advantages of the multilinks to transmit and receive data on the multiple links so as to achieve the advantages of high throughput, low time delay and the like.

In the related art, an NSTR (Non-simultaneous Transmission and Reception) STA MLD is also defined, and in NSTR STA MLD supporting multiple links, due to the limitation of Radio Frequency (RF) and the like, when STA1 transmits (Transmission) data on link 1, mutual Interference (in-Device Interference) is caused in STA MLD, which results in that STA2 cannot normally receive (receive) data on link 2, and further, NSTR STA MLD cannot independently and simultaneously transmit and receive data on multiple links. That is, when NSTR STA MLD uses multiple links simultaneously, NSTR STA MLD transmits (also referred to as transmitting) or receives data simultaneously over the multiple links.

As shown in fig. 5, which illustrates the Uplink (UL) procedure, in the ideal case NSTR STA MLD aligns (Align) the point in time when data is transmitted on both links and aligns (Align) the point in time when data is received. UL PPDU is a physical layer Protocol Data Unit (PHY Protocol Data Unit) transmitted in an uplink procedure, and BA is a Block Acknowledgement (Block Acknowledgement) received in a downlink procedure.

Because in the related art multilink operation, transmission or reception between the multiple links cannot be aligned. When the link 2 performs data interaction (data transmission or data reception), if the link 1 needs to perform transmission, it needs to be considered that the expected transmission of the link 1 will not interfere with the link 2 performing data interaction, so that the link 2 cannot perform normal data interaction.

Based on the above, in the related art, for the STA MLD and the AP MLD with built NSTR Links (NSTR multilink), when the STA MLD or the AP MLD obtains the channel use right for a certain AC (Access Code) Queue on the link 1 by using the channel backoff Access procedure, that is, obtains a TxOP (Transmission Opportunity) of the AC Queue on the link 1, the STA MLD or the AP MLD may determine: if the trigger starts to transmit the data packet on the AC Queue, it will not interfere with the transceiving sequence (frame exchange sequence) on the link 2. The STA MLD or the AP MLD may determine whether to trigger transmission of a data packet on the AC Queue based on the determination.

As shown in fig. 6, for NSTR STA MLD, when STA1 on link 1 gets a TxOP, it is found that the transmit data (TX PPDU) expected to start will cause interference to the receive data (RX PPDU) being on link 2 on STA2, so STA1 decides not to start transmitting data at time point 301.

In summary, when the channel backoff procedure is applied to NSTR STA MLD or NSTR AP MLD, the transmission on link 1 needs to consider data interaction on link 2, so that there is a scenario where the channel backoff procedure needs to be restarted when the channel is in an idle state.

Referring to fig. 7, a flowchart of a channel access method provided in an exemplary embodiment of the present application is shown, where the method includes:

step 701, when the channel state is idle and it is determined to restart the channel backoff access procedure, performs the following steps: in the first channel backoff access process, obtaining a transmission opportunity but abandoning the transmission; executing a second channel backoff access process; and the first channel backoff access process is the last channel backoff access process of the second channel backoff access process.

In some optional embodiments, step 701 is performed by a wireless communication device, the wireless communication device comprising a STA or an AP. Taking a wireless communication device as an STA for example, when the STA determines that a channel to be used is in a busy state, the STA starts a first channel backoff access process at the end time of the busy state. At the end of the first channel backoff access procedure, the STA obtains a transmission opportunity, and the channel is in an idle state. However, the STA decides to start the second channel backoff access procedure and abandons the transmission.

It should be noted that, for an STA, the channel being in a busy state may be that other STAs are occupying on the channel of the current STA, or there is other interference on the channel of the current STA, or the current STA is performing data interaction on the channel.

In some optional embodiments, the channel backoff access procedure comprises at least: DCF, EDCA backoff, and other CSMA/CA based channel backoff access procedures. Among these, DCF and EDCA backoff have been described in detail above. In the following embodiments only EDCA back-off is exemplified.

Note that the method shown in fig. 7 may be employed in a busy channel state. At this time, step 701 may be implemented as follows: for the STA or AP on the NSTR Link, under the condition that the channel backoff access process is decided to be restarted, the following steps are adopted: in the first channel backoff access process, obtaining a transmission opportunity but abandoning the transmission; executing a second channel backoff access process; and the first channel backoff access process is the last channel backoff access process of the second channel backoff access process.

In other alternative embodiments, in the execution of the first channel backoff access procedure, if it is found that the data expected to be transmitted on link 1 will affect the data to be received on link 2, in the started first channel backoff access procedure, the transmission is aborted even if a transmission opportunity is obtained, and a second channel backoff access procedure is started to hopefully avoid the mutual interference between link 1 and link 2 by restarting the channel backoff access procedure.

In alternative embodiments, step 701 may be replaced with steps 701-1 and 701-2.

Step 701-1, in the first channel backoff access process, obtaining a transmission opportunity but abandoning the transmission;

step 701-2, executing a second channel backoff access process under the condition that the channel state is idle and the channel backoff access process is determined to be restarted; and the first channel backoff access process is the last channel backoff access process of the second channel backoff access process.

In alternative embodiments, step 701 may be replaced with step 701'.

Step 701', when the channel state is idle and it is decided to restart the channel backoff access procedure, the channel access procedure is executed in a target manner; wherein the last channel backoff access procedure to restart the channel backoff access procedure obtains a transmission opportunity but abandons the transmission.

In summary, when the channel status is idle and it is determined to restart the channel backoff access procedure, the following steps are performed: in the first channel backoff access process, obtaining a transmission opportunity but abandoning the transmission; executing a second channel backoff access process; the first channel backoff access process is the last channel backoff access process of the second channel backoff access process, and a mode for restarting the channel backoff access process based on the fact that the channel is in an idle state is provided.

Referring to fig. 8, a flowchart of a channel access method provided in an exemplary embodiment of the present application is shown. The method comprises the following steps:

step 801, starting a first channel backoff access process under the condition that a channel is in a busy state;

in some alternative embodiments, the method illustrated in fig. 8 is performed by a first wireless communication device corresponding to an NSTR link in an MLD. The wireless communication device includes any one of a STA and an AP. Optionally, the first wireless communication device is STA1, and the second wireless communication device is STA 2; or the first wireless communication device is AP1 and the second wireless communication device is AP 2. For convenience of illustration, the following description will be made by taking the first wireless communication device as STA1 and the second wireless communication device as STA 2.

Referring to fig. 9 and 10 in combination, it is shown that STA1 starts EDCA backoff, i.e., STA1 starts the first channel backoff access procedure, at the end time when STA1 determines that the channel is in a busy state.

Step 802, in case that the first channel backoff access process obtains a transmission opportunity but the transmission started in anticipation causes interference to the data interaction of the second wireless communication device in the MLD, abandoning the transmission;

in an alternative embodiment, the first wireless communication device gets a transmission opportunity at the end of the first channel backoff access procedure, but the first wireless communication device finds that the transmission that is expected to be initiated interferes with the data interaction of the second wireless communication device, and the first wireless communication device gives up the transmission.

Step 803, deciding to start a second channel backoff access procedure;

the first wireless communication device gives up the transmission and decides to restart the channel backoff access procedure, i.e. decides to start the second channel backoff access procedure.

Step 804, under the condition that the channel is in an idle state and the channel backoff access process is determined to be restarted, starting a second channel backoff access process at a time reference point; wherein the time reference point is a time point for deciding to start the second channel backoff access process.

Optionally, the time reference point has the following two possible determination modes;

the time reference point is the point in time at which the first wireless communication device decides to abandon the transmission;

referring collectively to fig. 9, which illustrates STA1 acquiring a transmission opportunity at time point 901 but deciding not to initiate a transmission, the current channel is idle, and STA1 resumes EDCA backoff (i.e., begins a second channel backoff access procedure) on link 1. STA1 finds that the TX PPDU expected to start at time point 901 causes interference to the RX PPDU of STA 2.

The time reference point is the point in time when the first wireless communication device, after dropping transmission, rediscovered that the expected initiated transmission no longer caused interference to the data interaction of the second wireless communication device in the MLD.

Referring collectively to fig. 10, which shows STA1 obtaining a transmission opportunity at time 1001 but deciding not to start transmission, STA1 finds at time 1001 that the TX PPDU expected to start causes interference to the RX PPDU of STA 2. STA1 temporarily assumes that STA1 has no data packet to send on this AC Queue, i.e., assumes that this AC Queue is an empty Queue, so STA1 may not trigger start of transmission at time 1001 and keep the channel backoff window of EDCA backoff on this AC Queue at 0 until at subsequent time 1002, when STA2 considers that the data packet triggering start of AC Queue will not interfere with data interaction on link 2, STA1 may regard AC Queue as a non-empty Queue again, when the current channel is idle, STA1 performs EDCA backoff on link 1 again, i.e., STA1 starts a second channel backoff access procedure on link 1.

In some optional embodiments, the first wireless communication device further aligns the time reference point to a boundary of a corresponding last Slot of the first wireless network device. In the case where the time reference point is a point in time at which the first wireless communication device decides to abandon transmission, the time reference point is aligned to the slot boundary 901 as shown in fig. 9. In the case where the time reference point is the point in time when the transmission expected to be initiated is no longer causing interference to the data interaction of the second wireless communication device in the MLD after the first wireless communication device gives up the transmission, the time reference point is aligned to the slot boundary 1002 as shown in fig. 10.

In some optional embodiments, starting the second channel backoff access procedure at the time reference point comprises:

1, starting from a time reference point, carrying out channel detection in a first time period;

optionally, when the channel backoff access procedure is DCF, the first time period may be DIFS in the above description, where DIFS is SIFSTime +2 SlotTime. From the above description, SIFS is D1+ M1+ Rx/Tx, SlotTime is D2+ CCAdel + M2+ Rx/Tx. Optionally, when the channel backoff access procedure is EDCA backoff, the first time period may be AIFS described above, where AIFS is SIFSTime + AIFSN SlotTime. It can be seen from the above description that different ACs may have different AIFSN values, and a larger AIFSN value indicates a lower priority of the current first wireless communication device. Referring to fig. 9 and 10 in combination, it is shown that the STA1 performs a new EDCA backoff, where AIFS is the first time period.

2, under the condition that the channel detection result in the first time period is idle, carrying out channel detection in the ith second time period in n second time periods Slot, wherein n is the number of backoff time periods, and the initial value of i is 1 and i is not more than n;

in some optional embodiments, the EDCA backoff procedure includes an IFS channel detection phase (first time period) and a random backoff phase, the random backoff phase including n slots (second time period).

As can be seen from the above, the first time period includes SIFS and several slots. The channel detection result in the first time period is idle, and may be idle in both SIFS and several slots; the channel detection result on the SIFS may be busy, and the channel detection results on several slots may be idle.

3, when the channel detection result in the ith second time period is idle and n is not 0, subtracting n by one, adding i by 1 and then performing the channel detection on the ith second time period in the n second time periods again;

and when the detection result of the first wireless communication device for carrying out channel detection on the ith slot is that the channel is in an idle state and n is not 0, the first wireless communication device subtracts 1 from the number of the backoff slots, and continues to carry out channel detection on the (i + 1) th slot until the number of the backoff slots is 0. Referring to fig. 9 and 10 in combination, this shows the process where the STA1 performs a new EDCA backoff and the backoff slot number is gradually reduced to 0.

And 4, under the condition that the channel detection result in the ith second time period is idle and n is 0, determining that the second channel backoff access process obtains the transmission opportunity.

And when the detection result of the first wireless communication device performing channel detection on the ith slot is that the channel is in an idle state and n is not 0, the first wireless communication device determines that the second channel backoff access process obtains a transmission opportunity.

Referring collectively to fig. 9 and 10, which illustrate the STA1 performing a new EDCA backoff (i.e., a second channel backoff access procedure), the STA1 has an opportunity to acquire a TX PPDU (transmission data) after the backoff slot number gradually decreases to 0.

Note that the method shown in fig. 8 may be employed in a busy channel state. At this point, step 804 may be implemented as follows: for an STA or an AP on the NSTR Link, under the condition of deciding to restart the channel backoff access process, starting a second channel backoff access process at a time reference point; wherein the time reference point is a time point for deciding to start the second channel backoff access process.

In summary, by starting the second channel backoff access procedure at the time reference point, a possible implementation of restarting the channel backoff access procedure is provided.

And the time reference point is a time point when the first wireless communication device decides to abandon the transmission, or the time reference point is a time point when the first wireless communication device redisfinds that the expected started transmission does not cause interference to the data interaction of the second wireless communication device in the MLD after abandoning the transmission, and further provides a specific implementation means for starting a backoff access process of the second channel based on the channel in the idle state.

Referring to fig. 11, a flowchart of a channel access method provided in an exemplary embodiment of the present application is shown. The method comprises the following steps:

step 1101, starting a first channel backoff access process under the condition that a channel is in a busy state;

in some alternative embodiments, the method illustrated in fig. 11 is performed by a first wireless communication device corresponding to an NSTR link in an MLD. In some optional embodiments, the wireless communication device comprises any one of a STA and an AP. Optionally, the first wireless communication device is STA1, and the second wireless communication device is STA 2; or the first wireless communication device is AP1 and the second wireless communication device is AP 2. For convenience of illustration, the following description will be made by taking the first wireless communication device as STA1 and the second wireless communication device as STA 2.

Referring collectively to fig. 12, fig. 12 shows that at the end of the time when STA1 determines that the channel is busy, STA1 starts EDCA backoff, i.e., STA1 starts the first channel backoff access procedure.

Step 1102, in case that the first channel backoff access procedure obtains a transmission opportunity but the transmission initiated is expected to cause interference to data interaction of the second wireless communication device in the MLD, abandoning the transmission;

Step 1103, deciding to start a second channel backoff access procedure;

Step 1104, under the condition that the channel state is idle and the start of the second channel backoff access process is decided, generating a channel busy signal at a time reference point, wherein the time reference point is a time point for deciding the start of the second channel backoff access process;

in some optional embodiments, the channel busy signal may be at least one of:

CCA (Clear Channel Assessment) busy signal;

NAV (Network Allocation Vector) information other than 0; the NAV may be understood as a time counter indicating how long the channel is still occupied, with each listening STA or AP maintaining a NAV counter. The value of the NAV decreases over time, and the STA or AP stops channel contention and data transmission by considering the channel busy until the NAV value decreases to zero.

A transceiving sequence;

in some alternative embodiments, the channel busy signal lasts for a first duration.

When the channel-busy signal comprises a CCA-busy signal, the first time duration may comprise an integer multiple of a detection time of the CCA-busy signal. Optionally, the duration of the detection time of the CCA busy signal is configured in advance; optionally, the end time of the detection time of the CCA busy signal is earlier than the end time of the data interaction of the second wireless communication device; optionally, an end time of the detection time of the CCA busy signal is equal to an end time of data interaction of the second wireless communication device.

When the channel busy signal includes NAV information other than 0, the first duration may include a duration of the NAV information. Optionally, the duration of the NAV information is preconfigured; optionally, the ending time of the NAV information is earlier than the ending time of the data interaction of the second wireless communication device; optionally, the end time of the NAV information is equal to the end time of the data interaction of the second wireless communication device.

The first duration may include a duration of data interaction of the transceiving sequence by the first wireless communication device when the channel busy signal includes the transceiving sequence. Optionally, the duration of the transceiving sequence is preconfigured; optionally, the end time of the transceiving sequence is earlier than the end time of the data interaction of the second wireless communication device; optionally, the end time of the transceiving sequence is equal to the end time of the data interaction of the second wireless communication device.

In some optional embodiments, the channel busy signal is a false channel busy signal. Optionally, the false channel-busy signal includes at least one of a false CCA-busy signal, false non-0 NAV information, and a false transceiving sequence.

In some alternative embodiments, referring to fig. 12, STA1 gets a transmission opportunity at the end time 1201 of the last EDCA backoff (i.e., the first channel backoff access procedure), but STA1 decides not to initiate transmission, then STA1 generates a channel-busy signal, the start time 1201 of the channel-busy signal is the time reference point of the new EDCA backoff, and then STA1 enters the IFS channel detection phase (AIFS) after the end time 1202 of the channel-busy signal.

In another alternative embodiment, referring to fig. 13, STA1 gets a transmission opportunity at time 1301 when the last EDCA backoff (i.e. the first channel backoff access procedure) ends, but STA1 decides not to initiate transmission, after which STA1 temporarily assumes that there is no packet to be transmitted on this AC Queue, i.e. assumes that this AC Queue is an empty Queue, so STA1 may not trigger initiation of transmission and keeps the channel backoff window of EDCA backoff at this AC Queue at 0 until, at a subsequent time 1302, STA2 considers that the packet triggering initiation of AC Queue at this time will not cause interference to data interaction on link 2, STA1 may regard AC Queue again as a non-empty Queue and generate a channel busy signal at that time, the start time of the channel busy signal is the time reference point of the new EDCA backoff 1302, after which the end time 1303, the STA enters an IFS channel detection phase (AIFS).

Step 1105, at the end of the busy signal, the second channel evasion access procedure is started.

Note that the method shown in fig. 11 may be employed in a busy channel state. At this point, step 1104 may be implemented as follows: for an STA or an AP on the NSTR Link, in case of deciding to restart the channel backoff access procedure, a channel busy signal is generated at a time reference point, which is a time point deciding to start the second channel backoff access procedure.

In summary, a channel busy signal is generated at the time reference point, so that the first wireless communication device starts the second channel backoff access process based on channel idle according to a predetermined manner of "starting the second channel backoff access process based on channel busy".

Referring to fig. 14, a flowchart of a channel access method provided in an exemplary embodiment of the present application is shown. The method comprises the following steps:

step 1401, under the condition that the channel is in a busy state, starting a first channel backoff access process;

in some alternative embodiments, the method shown in fig. 14 is performed by a first wireless communication device corresponding to an NSTR link in an MLD. In some optional embodiments, the wireless communication device comprises any one of a STA and an AP. Optionally, the first wireless communication device is STA1, and the second wireless communication device is STA 2; or the first wireless communication device is AP1 and the second wireless communication device is AP 2. For convenience of illustration, the following description will be made by taking the first wireless communication device as STA1 and the second wireless communication device as STA 2.

Referring collectively to fig. 15, fig. 15 shows that at the end of the time when STA1 determines that the channel is busy, STA1 starts EDCA backoff, i.e., STA1 starts the first channel backoff access procedure.

Step 1402, in case that the first channel backoff access procedure obtains a transmission opportunity but the transmission initiated is expected to cause interference to data interaction of the second wireless communication device in the MLD, abandoning the transmission;

Step 1403, deciding to start a second channel backoff access procedure;

the first wireless communication device gives up the transmission and decides to start the second channel backoff access procedure.

Step 1404, in the time of data interaction of the second wireless communication device, the first wireless communication device determines that the channel is busy when the channel state is idle and it is determined to restart the channel backoff access process;

in some optional embodiments, the first wireless communication device regards the transceiving sequence of the second wireless communication device as the transceiving sequence of the first wireless communication device; at the end of the transceiving sequence of the first wireless communication device, the first wireless communication device starts a second backoff channel access procedure.

Referring collectively to fig. 15, STA1 gets a transmission opportunity at the end time 1501 of the last EDCA backoff (first channel backoff access procedure), but STA1 decides not to start transmission, and then STA1 regards the transceiving sequence of STA2 as its own transceiving sequence. At end time 1502 of the transceiving sequence of STA2, STA1 starts a new EDCA backoff, i.e., STA1 starts a second channel backoff access procedure.

Step 1405, after the data interaction of the second wireless communication device is completed, the first wireless communication device starts a second backoff channel access procedure.

Note that the method shown in fig. 14 may be employed in a busy channel state. At this point, step 1404 may be implemented as follows: for the STA or the AP on the NSTR Link, under the condition that the channel backoff access process is decided to be restarted, the first wireless communication device determines the channel to be busy in the data interaction time of the second wireless communication device.

In summary, by using the transceiving sequence of the second wireless communication device as the transceiving sequence of the first wireless communication device, the channel backoff access procedure is restarted at the end of the transceiving sequence of the first wireless communication device, so that the first wireless communication device starts the second channel backoff access procedure based on channel idle according to the manner of "starting the second channel backoff access procedure based on channel busy" in advance. And the first wireless communication device can start the second channel evasion access process as soon as possible.

It is understood that the above method embodiments can be implemented individually or in combination, and the application is not limited thereto.

Fig. 16 is a block diagram illustrating a channel access apparatus according to an exemplary embodiment of the present application, where the apparatus includes:

a processing module 1601, configured to, when the channel status is idle and it is determined to restart the channel backoff access procedure, perform the following steps: in the first channel backoff access process, obtaining a transmission opportunity but abandoning the transmission; executing a second channel backoff access process; wherein the first channel backoff access procedure is a last channel backoff access procedure of the second channel backoff access procedure.

In some optional embodiments, the processing module 1601 is further configured to start a second channel backoff access procedure at a time reference point; wherein the time reference point is a time point for deciding to start the second channel backoff access process.

In some optional embodiments, the apparatus includes a first wireless communication device corresponding to an NSTR link in the MLD, and the relinquishing transmission is due to the first wireless communication device discovering that an expected initiated transmission interferes with data interaction with a second wireless communication device in the MLD.

In some alternative embodiments, the time reference point is a point in time when the first wireless communications device decides to relinquish transmission.

In some alternative embodiments, the time reference point is a point in time when the first wireless communication device, after dropping transmission, rediscover that the expected initiated transmission is no longer causing interference to data interaction with the second wireless communication device in the MLD.

In some optional embodiments, the processing module 1601 is further configured to perform channel detection over a first time period starting from a time reference point; under the condition that a channel detection result in the first time period is idle, carrying out channel detection in the ith second time period in n second time periods Slot, wherein n is the number of backoff time periods, and the initial value of i is 1 and i is not more than n; when the channel detection result in the ith second time period is idle and n is not 0, subtracting n by one, adding i by 1 and then performing channel detection on the ith second time period in the n second time periods again; and under the condition that the channel detection result in the ith second time period is idle and n is 0, determining that the channel backoff access process obtains the transmission opportunity.

In some optional embodiments, the processing module 1601 is further configured to align the time reference point to a boundary of a corresponding last timeslot of the first wireless communication device.

In some optional embodiments, the processing module 1601 is further configured to generate a channel busy signal at a time reference point, where the time reference point is a time point when the second channel backoff access procedure is decided to start; and starting a second receding channel access process at the end time of the busy signal of the channel.

In some optional embodiments, the channel busy signal comprises any one of the following signals: a CCA busy signal, NAV information other than 0, and a transceiving sequence.

In some optional embodiments, the processing module 1601 is further configured to determine that the channel is busy during a time of data interaction by the second wireless communication device; and after the data interaction of the second wireless communication equipment is finished, starting a second receding channel access process.

In some optional embodiments, the processing module 1601 is further configured to use the transceiving sequence of the second wireless communication device as the transceiving sequence of the first wireless communication device; and starting a second avoidance channel access process at the end time of the transceiving sequence of the first wireless communication device.

In summary, when the channel status is idle and it is determined to restart the channel backoff access procedure, the following steps are performed: in the first channel backoff access process, obtaining a transmission opportunity but abandoning the transmission; performing a second channel backoff access procedure provides a way to restart the channel backoff access procedure.

It should be noted that, when the apparatus provided in the foregoing embodiment implements the functions thereof, only the division of each functional module is illustrated, and in practical applications, the above functions may be distributed by different functional modules according to actual needs, that is, the content structure of the device may be divided into different functional modules to implement all or part of the functions described above.

With regard to the apparatus in the above-described embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment related to the method, and will not be elaborated here.

Referring to fig. 17, a schematic structural diagram of an MLD according to an embodiment of the present application is shown, where the MLD may be a STA MLD or an AP MLD. STA MLD includes STA1 and STA 2; the AP MLD includes AP1 and AP 2. Taking MLD as STA MLD 1700 for example, STA1 and STA2 share processor 1701, STA1 further includes transceiver 1702 and memory 1703, and STA2 further includes transceiver 1704 and memory 1705.

The processor 1701 includes one or more processing cores, and the processor 1701 executes various functional applications by executing software programs and modules.

The transceiver 1702 may be used for receiving and transmitting information, and the transceiver 1702 may be a communication chip. The transceiver 1704 is similar to the transceiver 1702 and will not be described further.

The memory 1703 may be used to store a computer program for execution by the processor 1701 to perform the various steps performed by the wireless communication device in the above-described method embodiments. The memory 1705 is similar to the memory 1703 and will not be described in detail.

Further, the memory 1703 may be implemented by any type or combination of volatile or non-volatile storage devices, including, but not limited to: Random-Access Memory (RAM) and Read-Only Memory (ROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), flash Memory or other solid state Memory technologies, Compact Disc Read-Only Memory (CD-ROM), high density Digital Video Disc (DVD) or other optical storage, magnetic tape cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices.

In another possible MLD configuration, STA1 and STA2 have respective processors.

In another possible MLD configuration, STA1 and STA2 share the same memory.

An embodiment of the present application further provides a computer-readable storage medium, where a computer program is stored in the storage medium, and the computer program is used for being executed by a processor to implement the above channel access method.

Optionally, the computer-readable storage medium may include: Read-Only Memory (ROM), Random-Access Memory (RAM), Solid State Drive (SSD), or optical disc, etc. The Random Access Memory may include a Resistance Random Access Memory (ReRAM) and a Dynamic Random Access Memory (DRAM).

The embodiment of the present application further provides a chip, where the chip includes a programmable logic circuit and/or a program instruction, and when the chip runs, the chip is configured to implement the above channel access method.

The embodiment of the present application further provides a computer program product or a computer program, where the computer program product or the computer program includes computer instructions, and the computer instructions are stored in a computer-readable storage medium, and a processor reads and executes the computer instructions from the computer-readable storage medium, so as to implement the above-mentioned channel access method.

The processor in the embodiment of the application comprises: application Specific Integrated Circuit (ASIC).

It should be understood that "indication" mentioned in the embodiments of the present application may be a direct indication, an indirect indication, or an indication of an association relationship. For example, a indicates B, which may mean that a directly indicates B, e.g., B may be obtained by a; it may also mean that a indicates B indirectly, for example, a indicates C, and B may be obtained by C; it can also mean that there is an association between a and B.

In the description of the embodiments of the present application, the term "correspond" may indicate that there is a direct correspondence or an indirect correspondence between the two, may also indicate that there is an association between the two, and may also indicate and be indicated, configure and configured, and so on.

Reference herein to "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

In addition, the step numbers described herein only show an exemplary possible execution sequence among the steps, and in some other embodiments, the steps may also be executed out of the numbering sequence, for example, two steps with different numbers are executed simultaneously, or two steps with different numbers are executed in a reverse order to the illustrated sequence, which is not limited in this application.

Those skilled in the art will recognize that, in one or more of the examples described above, the functions described in the embodiments of the present application may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The above description is only exemplary of the present application and should not be taken as limiting the present application, and any modifications, equivalents, improvements and the like that are made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for channel access, the method comprising:

in the first channel backoff access process, obtaining a transmission opportunity but abandoning the transmission;

executing a second channel backoff access process;

wherein the first channel backoff access procedure is a last channel backoff access procedure of the second channel backoff access procedure.

2. The method of claim 1, wherein performing a second channel backoff access procedure comprises:

starting the second channel backoff access procedure at a time reference point;

wherein the time reference point is a time point at which the second channel backoff access procedure is decided to start.

3. The method of claim 2, wherein the method is performed by a first wireless communication device that is not capable of transceiving NSTR links simultaneously in a multi-link device (MLD), and wherein the relinquishing transmission is due to the first wireless communication device discovering that an expected initiated transmission interferes with data interaction with a second wireless communication device in the MLD;

the time reference point is a point in time when the first wireless communication device decides to relinquish transmission;

or the like, or, alternatively,

the time reference point is a point in time when the first wireless communication device rediscovered the expected initiated transmission from causing no interference to data interaction with the second wireless communication device in the MLD.

4. The method of claim 2, wherein the starting the second channel backoff access procedure at a time reference point comprises:

performing channel detection over a first time period starting from the time reference point;

when the channel detection result in the first time period is idle, carrying out channel detection in the ith second time period in n second time periods Slot, wherein n is the number of backoff time periods, and the initial value of i is 1 and i is not more than n;

subtracting n from one, adding i to 1, and then performing channel detection again on the ith second time period in the n second time periods when the channel detection result on the ith second time period is idle and n is not 0;

and under the condition that the channel detection result in the ith second time period is idle and n is 0, determining that the second channel backoff access process obtains a transmission opportunity.

5. The method of claim 3, further comprising:

aligning the time reference point to a boundary of a corresponding last time slot of the first wireless communication device.

6. The method of claim 1, wherein performing a second channel backoff access procedure comprises:

generating a channel busy signal at a time reference point, wherein the time reference point is a time point for deciding to start the second channel backoff access process;

and starting the second channel evasion access process at the finishing moment of the channel busy signal.

7. The method of claim 6, wherein the channel busy signal comprises any one of the following signals:

clear channel assessment CCA busy signal;

non-0 network allocation vector NAV information;

and (4) receiving and transmitting sequences.

8. The method of claim 7, wherein the channel busy signal lasts for a first duration.

9. The method of claim 1, wherein the method is performed by a first wireless communication device corresponding to an NSTR link in a multi-link device, MLD, wherein the relinquishing transmission is due to the first wireless communication device discovering that an expected initiated transmission interferes with data interaction with a second wireless communication device in the MLD;

the executing the second channel backoff access procedure includes:

determining the channel as busy during the time of data interaction by the second wireless communication device;

and after the data interaction of the second wireless communication equipment is finished, starting the second receding channel access process.

10. The method of claim 9, wherein the determining the channel as busy during the time of the data interaction by the second wireless communication device comprises:

taking the transceiving sequence of the second wireless communication device as the transceiving sequence of the first wireless communication device;

after the data interaction of the second wireless communication device is completed, starting the second fallback-avoiding channel access process, including:

and starting the second receding channel access process at the end time of the transceiving sequence of the first wireless communication device.

11. A channel access apparatus, the apparatus comprising:

a processing module, configured to execute the following steps when the channel status is idle and it is determined to restart the channel backoff access procedure:

executing a second channel backoff access process;

12. The apparatus of claim 11,

the processing module is further configured to start the second channel backoff access procedure at a time reference point;

13. The apparatus of claim 12, wherein the apparatus comprises a first wireless communication device of a multi-link device MLD that is not capable of transceiving NSTR links simultaneously, and wherein the relinquishing transmission is due to the first wireless communication device discovering that an expected initiated transmission interferes with data interaction of a second wireless communication device of the MLD;

or the like, or, alternatively,

14. The apparatus of claim 12,

the processing module is further configured to perform channel detection over a first time period starting from the time reference point;

the processing module is further configured to perform channel detection on an ith second time period of the n second time periods Slot when the channel detection result in the first time period is idle, where n is the number of backoff time periods, and an initial value of i is 1 and i is not greater than n;

the processing module is further configured to, when the channel detection result in the ith second time period is idle and n is not 0, subtract n by one, add i by 1, and then perform the channel detection again in the ith second time period of the n second time periods;

the processing module is further configured to determine that the channel backoff access procedure obtains a transmission opportunity when the channel detection result in the ith second time period is idle and n is 0.

15. The apparatus of claim 13,

the processing module is further configured to align the time reference point to a boundary of a last timeslot corresponding to the first wireless communication device.

16. The apparatus of claim 11,

the processing module is further configured to generate a channel busy signal at a time reference point, where the time reference point is a time point for determining to start the second channel backoff access process;

the processing module is further configured to start the second channel backoff access process at the end time of the channel busy signal.

17. The apparatus of claim 16, wherein the channel busy signal comprises any one of the following signals:

a CCA busy signal;

NAV information other than 0;

and (4) receiving and transmitting sequences.

18. The apparatus of claim 17, wherein the channel busy signal lasts for a first duration.

19. The apparatus of claim 11, wherein the apparatus comprises a first wireless communication device corresponding to an NSTR link in a multi-link device MLD, wherein the relinquishing transmission is due to the first wireless communication device discovering that an expected initiated transmission interferes with data interaction with a second wireless communication device in the MLD;

the processing module is further configured to determine that the channel is busy during a time when the second wireless communication device performs data interaction;

the processing module is further configured to start the second fallback channel access process after the data interaction of the second wireless communication device is completed.

20. The apparatus of claim 19,

the processing module is further configured to use a transceiving sequence of the second wireless communication device as a transceiving sequence of the first wireless communication device;

the processing module is further configured to start the second fallback channel access procedure at an end time of the transceiving sequence of the first wireless communication device.

21. A first wireless communication device, wherein the first wireless communication device comprises a processor;

the processor is configured to, when the channel state is idle and it is determined to restart the channel backoff access procedure, perform the following steps:

executing a second channel backoff access process;

22. A computer-readable storage medium, in which a computer program is stored, the computer program being adapted to be executed by a processor to implement the channel access method according to any one of claims 1 to 10.

23. A chip comprising programmable logic circuitry and/or program instructions for implementing the channel access method of any of claims 1 to 10 when the chip is in operation.

24. A computer program product, characterized in that it comprises computer instructions stored in a computer readable storage medium, from which a processor reads and executes said computer instructions to implement the channel access method according to any one of claims 1 to 10.