CN107041006B

CN107041006B - Method and device for transmitting data

Info

Publication number: CN107041006B
Application number: CN201610079307.4A
Authority: CN
Inventors: 李波; 杨懋; 朱俊
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2016-02-04
Filing date: 2016-02-04
Publication date: 2021-08-13
Anticipated expiration: 2036-02-04
Also published as: CN107041006A

Abstract

A method and apparatus for transmitting data, comprising: a first station sends a first frame to a second station; the first station determines first receiving power, wherein the first receiving power is the receiving power of the second station for receiving the first frame; the first station determines a first clear channel assessment CCA threshold value according to the first receiving power; the first station transmits a first data frame to the second station based on the first CCA threshold value. The efficiency of data transmission can be improved.

Description

Method and device for transmitting data

Technical Field

The present invention relates to the field of communications, and in particular, to a method and an apparatus for transmitting data in the field of wireless communications.

Background

In a Wireless Local Area Network (WLAN) application, when a Station (STA) has data to send, the Station must first monitor a busy/idle status of a channel, and the Station can access the channel only if the channel status satisfies physical "idle" and virtual "idle". The CCA threshold is used as a determining factor of channel physical "busy/idle" and determines whether a link can be used to transmit data. Existing Wireless Fidelity (WIFI) systems employ a fixed CCA threshold to listen to the channel.

In addition, for the uplink multi-user scenario, in the next generation WLAN, in order to improve throughput and transmission efficiency, it has become a common knowledge that an Access Point (AP) triggers a group of stations to perform parallel transmission (i.e., data transmission is performed by uplink multi-user parallel transmission) through a trigger frame. When the access point triggers a group of stations through the trigger frame, the channel state is determined to be idle at the access point side, however, the channel states of the station side and the access point side may be inconsistent, so after receiving the trigger frame, the group of stations still need to perform CCA detection, and only when the channel is determined to be idle, data can be transmitted, thereby increasing the system overhead.

Disclosure of Invention

The embodiment of the invention provides a method and a device for transmitting data, which are used for improving the efficiency of data transmission.

In a first aspect, a method for transmitting data is provided, including: a first station sends a first frame to a second station; the first station determines a first receiving power, wherein the first receiving power is the receiving power of the second station for receiving the first frame; the first station determines a first Clear Channel Assessment (CCA) threshold value according to the first receiving power; the first station transmits a first data frame to the second station based on the first CCA threshold value.

The first station firstly determines first receiving power of a second station for receiving a first frame, further determines a first CCA threshold value according to the first receiving power, and transmits a first data frame to the second station based on the first CCA threshold value, so that the CCA threshold value can be dynamically adjusted according to the current network condition, and the data transmission efficiency is improved.

In one possible implementation, the determining, by the first station, the first received power includes: the first station receives a second frame sent by the second station, wherein the second frame comprises the first receiving power; and the first station determines the first receiving power according to the second frame.

In a possible implementation manner, the determining, by the first station, a first CCA threshold value according to the first reception power includes: the first station determines the first CCA threshold according to a ratio between the first received power and a target SINR threshold, where the target SINR threshold represents a threshold of SINR corresponding to a data frame transmitted between the first station and the second station.

In one possible implementation, the method further includes: and the first station determines the target SINR threshold value, wherein the target SINR threshold value is an SINR threshold value corresponding to a preset target modulation and coding strategy MCS level, or the target SINR threshold value is an SINR threshold value corresponding to a preset service quality QoS level.

In one possible implementation, the method further includes: the first station receives an Acknowledgement (ACK) frame sent by the second station, wherein the ACK frame comprises second receiving power of the second station for receiving the first data frame; the first station determines a second CCA threshold value according to the second receiving power; and the first station transmits a second data frame to the second station based on the second CCA threshold value.

In one possible implementation, the method further includes: the first station determines a third CCA threshold value, where the third CCA threshold value is a weighted average of at least one historical CCA threshold value, the at least one historical CCA threshold value is a corresponding CCA threshold value when a data frame is sent to the second station for the last N times, and N is greater than or equal to 1; and the first station sends a third frame to the second station based on the third CCA threshold value.

In a possible implementation manner, the first frame is a request to send RTS frame; the second frame is a Clear To Send (CTS) frame.

In a second aspect, a method for transmitting data is provided, including: a second station receives a first frame sent by a first station; the second station determines a first receiving power for receiving the first frame; the second station sends a second frame to the first station, wherein the second frame comprises the first receiving power; the second station receives a first data frame transmitted by the first station based on a first CCA threshold value, wherein the first CCA threshold value is determined by the first station according to the first receiving power.

The second station firstly determines first receiving power for receiving a first frame sent by the first station, and carries the first receiving power in a second frame sent to the first station, so that the first station determines a first CCA threshold value according to the first receiving power, thereby dynamically adjusting the CCA threshold value according to a network condition and improving the efficiency of data transmission.

In one possible implementation manner, the method further includes: the second station determines a second receiving power for receiving the first data frame; the second station sends an ACK frame to the first station, where the ACK frame includes a second receiving power, so that the first station determines a second CCA threshold according to the second receiving power; and the second station receives a second data frame sent by the first station based on the second CCA threshold value.

In a possible implementation manner, the first frame is a request to send RTS frame; the second frame is a clear to send CTS frame.

In a third aspect, a method for transmitting data is provided, including: the method comprises the steps that a station receives a trigger frame sent by an access point, wherein the trigger frame is used for indicating at least one station including the station to transmit a data frame to the access point; the station determines whether the distance between the station and the access point is smaller than a preset distance according to the receiving power for receiving the trigger frame; and when the distance between the station and the access point is smaller than the preset distance, the station transmits a data frame to the access point, wherein the station does not need CCA detection.

In the process that the station transmits the data frame to the access point, the station determines the receiving power of the trigger frame sent by the access point, and further determines whether the distance between the station and the access point is smaller than a preset distance according to the receiving power, if the distance between the station and the access point is smaller than the preset distance, the station does not need to perform CCA detection, and therefore system overhead is reduced.

In a possible implementation manner, the determining whether the distance between the station and the access point is smaller than a preset distance includes: the station determines the distance between the station and the access point according to the sending power and the receiving power, wherein the trigger frame comprises the sending power, and the sending power is the sending power of the access point for sending the trigger frame; the station determines whether the distance between the station and the access point is less than the preset distance.

In a possible implementation manner, the determining, by the station, a distance between the station and the access point according to the transmission power and the reception power includes: the station is according to the formula Pr ═ Pt ═ d^-αAnd determining the distance between the station and the access point, wherein Pt represents the transmission power, Pr represents the reception power, d represents the distance between the station and the access point, and alpha represents a path loss factor.

In a possible implementation manner, the determining, by the station, whether a distance between the station and the access point is smaller than a preset distance according to the received power for receiving the trigger frame includes: the station determines whether the received power is less than a preset power; when the received power is smaller than the preset power, the station determines that the distance between the station and the access point is smaller than the preset distance.

In a fourth aspect, a method for transmitting data is provided, including: the access point determines a first group of stations; the access point sends a first trigger frame to the first group of stations, the first trigger frame is used for indicating the first group of stations to transmit data to the access point, the first trigger frame includes first information, the first information is used for indicating whether the distance between each station in the first group of stations and the access point is smaller than a preset distance, so that each station determines whether to perform CCA detection according to the first information, wherein the station whose distance between the access point is smaller than the preset distance does not need to perform CCA detection.

When the access point sends the first trigger frame to the first group of stations, the first information included in the first trigger frame is used for indicating whether the distance between each station in the first group of stations and the access point is smaller than the preset distance or not, so that each station can determine whether to perform CCA check or not according to the first information, the stations with the distance smaller than the preset distance from the access point do not need to perform CCA detection, and the overhead of the system is saved.

In one possible implementation manner, the method further includes: the access point determining a second set of stations; the access point sends a second trigger frame to the second group of stations, where the second trigger frame includes sending power of the access point sending the second trigger frame, so that each station in the second group of stations determines a distance between each station in the second group of stations and the access point according to the receiving power for receiving the trigger frame and the sending power.

In one possible implementation manner, the method further includes: the access point receives a data frame sent by a third group of stations, wherein the data frame comprises second information, and the second information indicates whether the distance between each station in the third group of stations and the access point is smaller than the preset distance; and the access point determines the size relationship between the distance between each station in the third group of stations and the access point and the preset distance according to the second information.

In one possible implementation, the determining, by the access point, a first set of stations includes: determining the first group of stations from the plurality of stations according to the size relation between the distance between the plurality of stations and the access point and a preset distance, wherein the distance between all the stations in the first group of stations and the access point is smaller than the preset distance, or the distance between all the stations in the first group of stations and the access point is larger than or equal to the preset distance.

In a fifth aspect, there is provided a station comprising means for performing the method of the first aspect.

In a sixth aspect, there is provided a station comprising means for performing the method of the second aspect.

In a seventh aspect, there is provided a station comprising means for performing the method of the third aspect.

In an eighth aspect, an access point is provided that includes means for performing the method of the fourth aspect.

In a ninth aspect, a station is provided that includes a memory, a processor, and a transceiver. The memory is for storing a program, the processor is for executing a program, and the transceiver is for communicating with other stations. The processor is adapted to perform the method of the first aspect when the program is executed.

In a tenth aspect, a station is provided that includes a memory, a processor, and a transceiver. The memory is for storing a program, the processor is for executing a program, and the transceiver is for communicating with other stations. The processor is adapted to perform the method of the second aspect when the program is executed.

In an eleventh aspect, a station is provided that includes a memory, a processor, and a transceiver. The memory is for storing a program, the processor is for executing a program, and the transceiver is for communicating with other stations. The processor is adapted to perform the method of the third aspect when the program is executed.

In a twelfth aspect, an access point is provided that includes a memory, a processor, and a transceiver. The memory is for storing a program, the processor is for executing a program, and the transceiver is for communicating with other stations. The processor is configured to perform the method of the fourth aspect when the program is executed.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, 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 system architecture diagram of transmitting data for a single user scenario in accordance with an embodiment of the present invention.

Fig. 2 is a schematic flow chart of a method of transmitting data in an embodiment of the present invention.

Fig. 3 is a diagram illustrating a method of transmitting data according to another embodiment of the present invention.

Fig. 4 is a diagram illustrating a method of transmitting data according to another embodiment of the present invention.

Fig. 5 is a diagram illustrating a method of transmitting data according to another embodiment of the present invention.

Fig. 6 is a diagram illustrating a method of transmitting data according to another embodiment of the present invention.

Fig. 7 is a diagram illustrating a method of transmitting data according to another embodiment of the present invention.

FIG. 8 is a system architecture diagram in a multi-user scenario in accordance with yet another embodiment of the present invention.

Fig. 9 is a schematic flow chart of a method of transmitting data according to yet another embodiment of the present invention.

Fig. 10 is a diagram illustrating a method of transmitting data according to still another embodiment of the invention.

Fig. 11 is a diagram illustrating a method of transmitting data according to still another embodiment of the invention.

Fig. 12 is a diagram illustrating a method of transmitting data according to still another embodiment of the invention.

Fig. 13 is a schematic diagram of a station transmitting data according to still another embodiment of the present invention.

Fig. 14 is a schematic diagram of a station transmitting data according to still another embodiment of the present invention.

Fig. 15 is a schematic diagram of a station transmitting data according to still another embodiment of the present invention.

Fig. 16 is a schematic diagram of an access point for transmitting data according to still another embodiment of the present invention.

Fig. 17 is a schematic diagram of a station for transmitting data according to still another embodiment of the present invention.

Fig. 18 is a schematic diagram of a station for transmitting data according to still another embodiment of the present invention.

Fig. 19 is a schematic diagram of a station transmitting data according to still another embodiment of the present invention.

Fig. 20 is a schematic diagram of an access point for transmitting data according to still another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

It should be understood that the technical solutions of the embodiments of the present invention can be applied to various communication systems, for example: a Global System for Mobile communications (GSM) System, a Code Division Multiple Access (CDMA) System, a Wideband Code Division Multiple Access (WCDMA) System, a General Packet Radio Service (GPRS), a Long Term Evolution (LTE) System, a LTE Frequency Division Duplex (FDD) System, a LTE Time Division Duplex (TDD), a WiMAX (Universal Mobile telecommunications System, UMTS), or a Worldwide Interoperability for Microwave Access (UMTS) communication System.

Fig. 1 shows a system architecture diagram of transmission data of a single user scenario in an embodiment of the invention. As shown in fig. 1, the system may include a first station and a second station, wherein the first station and the second station communicate via a wireless link. The first station is used for sending data to the second station. The first station and the second station may be an access point and a station. The first site and the second site may both be sites. Or the first station may also be denoted as a sending side, and the second station may also be denoted as a receiving side, before transmitting data, the sending side needs to perform CCA detection to determine a busy-idle state of a channel, and when the channel state is idle, the sending side transmits data to the receiving side. In the prior art, a fixed CCA threshold value is adopted for CCA detection, which cannot be dynamically adjusted according to network conditions, thereby affecting the efficiency of data transmission.

A method 200 for transmitting data according to an embodiment of the present invention is described below, where the method 200 may be performed by a station or an access point, and the method 200 includes:

s210, a first station sends a first frame to a second station;

s220, the first station determines a first receiving power, where the first receiving power is a receiving power of the second station receiving the first frame;

s230, the first station determines a first clear channel assessment CCA threshold according to the first receiving power;

s240, the first station transmits a first data frame to the second station based on the first CCA threshold.

Alternatively, the first frame may be a Request To Send (RTS) frame; the second frame may be a Clear To Send (CTS) frame. Alternatively, the first frame may be a data frame, the second frame may be an Acknowledgement (ACK) frame for acknowledging the data frame, and the first frame and the second frame may be other types of frames, which is not limited in this respect.

Alternatively, the second station may be an access point or a station. That is, both the transceiver transmitting data may be data transmission between the access point and the station, or data transmission between the stations, which is not limited by the present invention.

Optionally, in 220, the determining, by the first station, the first received power may be: the first station receives a second frame sent by the second station, wherein the second frame comprises the first receiving power; and the first station determines the first receiving power according to the second frame. It can also be: the first station estimates a first received power based on historical information of frames transmitted between the first station and the second station.

Optionally, in 230, the first station determines the first CCA threshold according to the first received power, which may be determined according to a Signal to Noise Ratio (SNR) of the first received power and a target Signal. Alternatively, the first reception power may be determined based on a Ratio (SINR) of the first reception power to the target Signal to the Interference and Noise. The target SNR or target SINR may be a threshold value of SNR or SINR corresponding to data frames transmitted between the first station and the second station. Or, after receiving the data frame, the second station demodulates the SNR or SINR threshold corresponding to the data frame. The value of the target SNR threshold or the target SINR threshold may be a value predetermined between the first station and the second station. For example, the SINR threshold may be a SINR threshold corresponding to a Modulation and Coding Scheme (MCS) level of 0 (i.e., MCS0), which is not limited in the present invention.

Optionally, in 240, the first station transmits a first data frame to the second station based on the first CCA threshold value. The corresponding channel may be sensed based on the first CCA threshold value, so as to determine a busy-idle status of the channel, and when the channel status is idle, the first station transmits the first data frame to the second station. Or, the backoff may be performed based on the first CCA threshold value, and when the backoff is up to 0, the first data frame may be transmitted to the second station. The invention is not limited in this regard.

Optionally, as an embodiment, in the method 200, the determining, by the first station, a first CCA threshold value according to the first reception power includes: the first station determines the first CCA threshold according to a ratio between the first received power and a target signal to interference noise ratio SINR threshold, where the target SINR threshold represents a threshold of SINR corresponding to a data frame transmitted between the first station and the second station.

Optionally, the first CCA threshold may be determined according to the formula CCA ═ Pr/SINR; wherein Pr represents the first received power, CCA represents the first CCA threshold, and SINR represents a signal to interference plus noise ratio, SINR, threshold.

Alternatively, the first CCA threshold may also be determined according to the formula CCA ═ (Pr ± Δ)/SINR; where Pr represents the first received power, CCA represents the first CCA threshold, SINR represents a signal to interference plus noise ratio, SINR, threshold, and delta represents an increment. The delta representation adjusts the first CCA threshold value using a delta to account for the different power of the first frame from the data frame, such that the first CCA threshold value can be dynamically adjusted.

For example, the target SINR threshold may be an SINR threshold corresponding to a predetermined MCS level. Such as the SINR threshold corresponding to MCS 0.

For another example, the target SINR may be an SINR threshold value corresponding to a predetermined Quality of Service (QoS) level. For example, a high QoS may correspond to a lower SINR threshold, and thus a higher CCA threshold, so that the concurrency of the high QoS traffic is high and the transmission probability is high. The low QoS is corresponding to a higher SINR threshold value and thus a lower CCA threshold value, so that the concurrency of the low QoS service is low, the transmission probability is low, and the requirement of the service QoS is guaranteed.

Optionally, the method 200 further comprises: the first station receives an Acknowledgement (ACK) frame sent by the second station, wherein the ACK frame comprises second receiving power of the second station for receiving the first data frame; the first station determines a second CCA threshold value according to the second receiving power; and the first station transmits a second data frame to the second station based on the second CCA threshold value.

Fig. 2 shows a schematic flow chart of a method of transmitting data according to a further embodiment of the invention. In fig. 2, the second station obtains the received power Pr after receiving the RTS frame of the first station, and if Pr > Pth, determines that the distance between the second station and the first station is less than the predetermined distance, where Pth represents a preset power for determining whether the second station and the first station belong to the close range. It may be considered that, when the distance between the second station and the first station is short, the channel consistency between the second station and the first station is high, so that the first station may calculate the first CCA threshold, and the first CCA threshold may reflect the channel condition of the second station more accurately. When the distance between the first station and the second station is long, the consistency of the channels perceived by the two transceivers is poor, so that the first CCA threshold calculated by the first station deviates from optimality, or the channel state of the second station cannot be accurately reflected, and therefore, when the distance between the two transceivers is long, the existing method for fixing the CCA threshold can be selected to transmit data.

Specific embodiments of the present invention will be described in detail below with reference to fig. 3 to 7.

Fig. 3 is a schematic diagram illustrating a method of transmitting data according to another embodiment of the present invention. In the embodiment of the invention, the first station calculates the CCA threshold value according to the receiving power of the second station through one RTS/CTS interaction, and the CCA threshold value is used as the busy/idle threshold of the first station for listening to the channel next time.

The specific steps of the method in fig. 3 are described below.

301, a first station sends an RTS frame;

302, after receiving the RTS frame, the second station determines a first received power Pr, replies to the CTS frame after a certain duration (e.g., a Short Interframe Space (SIFS) duration), and carries the first received power Pr in the CTS frame;

and 303, after receiving the CTS frame, the first station reads out the first received power Pr, calculates a CCA threshold (denoted as CCA) according to a formula of CCA ═ Pr ± Δ)/SINR, and uses the CCA threshold as a CCA threshold for transmitting a data frame next time. And after a certain time, sending the data frame to the second station.

304, after receiving the data frame, the second station sends an ACK frame acknowledgement after a certain duration (for example, SIFS duration), and completes the transmission.

Fig. 4 shows a schematic diagram of data transmission according to another embodiment of the present invention, in the embodiment shown in fig. 4, a scenario of RTS/CTS exemption is mainly considered, that is, when data transmission does not require RTS/CTS transmission within a period of time T (time T may be specified by a protocol, or an access point broadcasts a notification), a second station carries a received power Pr when receiving a previous data frame when replying an ACK frame, and after receiving an ACK frame, a first station calculates a CCA threshold according to Pr, and uses the CCA threshold as a threshold for a next time when the first station listens to a busy channel.

The specific steps of the method of fig. 4 are described below.

401: and the first station backs off according to the CCA threshold value (expressed as CCA) calculated after the transmission of the previous data frame is finished, and when the back-off is up to 0, the first station sends the data frame.

402: and after receiving the data frame, the second station acquires the received power Pr, and replies ACK and carries the received power Pr after a certain time length.

403: and after receiving the ACK frame, the first station reads out the received power Pr, calculates a CCA threshold value according to a formula CCA ═ Pr +/-Delta)/SINR, and updates the CCA threshold value.

404: and the first station backs off by using the updated CCA threshold value, and when the back-off is up to 0, the first station sends a data frame. Repeating steps 402 and 403; until time T is over, go to 405.

405: the first station backs off with the updated CCA threshold, and the two transceivers send data in an RTS/CTS interaction manner, and the subsequent steps are as described in the embodiment in fig. 3, which is not described herein again.

Fig. 5 shows a schematic diagram of transmitting data according to another embodiment of the present invention. In the embodiment shown in fig. 5, it is mainly considered that when the first station and the second station are in a close-range scenario, the reliability of transmission is high, the change of the channel is small within a certain time, and the network condition can be considered as a quasi-static environment. After the first station and the second station determine the CCA threshold value through some RTS/CTS interaction, the first station and the second station may continue to use the CCA threshold value for the next time T.

The specific steps of the method in fig. 5 are described below.

And 501, the first station backs off according to a CCA threshold value (denoted as CCA x) calculated after the previous data frame transmission is finished, and when the backoff is up to 0, the first station sends the data frame.

502, after receiving the data frame, the second station obtains the received power Pr, and replies ACK and carries the received power Pr after a certain time period.

And 503, after receiving the ACK frame, the first station reads the received power Pr, calculates a first CCA threshold according to the formula CCA ═ Pr ± Δ/SINR, and updates the CCA threshold.

And 504, in a subsequent period of time T, the first station keeps performing backoff with the updated first CCA threshold value, and when the backoff reaches 0, sends a data frame. The second station replies ACK after a certain time length after receiving the data frame; step 504 is repeated until time T is over, and a transition is made to step 505.

505, the first station still performs backoff with the first CCA threshold, and the two transceivers send data in an RTS/CTS interaction manner, and the following steps are as described in the embodiment in fig. 3, and are not described again here.

Alternatively, in the scenario shown in fig. 5, when the first station and the second station continue to use the CCA threshold for the next time T after determining the CCA threshold through some RTS/CTS interaction, when the second station loses some ACK frame, the first station may immediately switch to the RTS/CTS mode, and advance the end time T.

Fig. 6 shows a schematic diagram of transmitting data according to still another embodiment of the present invention. In the embodiment shown in fig. 6, the case where both the transmitting and receiving sides use the RTS/CTS-free transmission mode and the transmitting side does not need to back off during the time T is mainly considered. That is, after the first station receives the ACK frame of the second station, the next data frame is directly sent after a certain time without backoff. And the receiving station carries the receiving power of the previous data frame in the ACK frame and sends the ACK frame to the first station, so that the first station calculates the CCA threshold value.

The specific steps of the method in fig. 6 are described below. As shown in fig. 6, after one RTS/CTS interaction, both the transmitter and the receiver determine to adopt the RTS/CTS-free transmission mode for the next period of time T.

601, the first station contends to the channel and sends an RTS frame.

And 602, after receiving the RTS frame, the second station determines the received power Pr, replies to the CTS after a certain duration (for example, SIFS duration), and carries the received power Pr.

603, after receiving the CTS frame, the first station reads the received power Pr, calculates the CCA threshold according to the formula CCA ═ Pr +/- Δ/SINR, and updates the CCA threshold.

604, the first station does not need to back off; after a certain time period (e.g., SIFS time period), a data frame is transmitted based on the updated CCA threshold value,

605, after receiving the data frame, the second station replies an ACK frame after a certain time duration (for example, SIFS time duration) and carries the received power Pr in the ACK frame, where the received power Pr is used by the sending end to calculate and update the CCA threshold. Steps 604 and 605 are repeated until time T is over, proceeding to step 606.

606, the first station backs off with the latest CCA threshold value, and both the transceiver and the transceiver transmit data in an RTS/CTS interaction manner, and the subsequent steps are as described in the embodiment of fig. 3, and are not described here again.

Fig. 7 shows a schematic diagram of transmitting data according to still another embodiment of the present invention. In the embodiment shown in fig. 7, it is mainly considered that, when the first station transmits a data frame for the first time, the CCA threshold may be initialized, and the initialized CCA threshold may be a weighted average value according to the CCA threshold calculated N times before. And then, updating the CCA threshold according to the received power carried in the CTS frame or the ACK frame sent by the second station, and performing backoff when sending the data frame next time by using the updated CCA threshold.

The specific steps of the method of fig. 7 are described below.

701, before a first station sends data for the first time, a CCA threshold is initialized, the value of the CCA threshold is initialized to be a weighted average of historical CCA threshold values, and then backoff is performed by using the CCA threshold.

The first station backs off to 0 and sends an RTS frame 702.

703, after receiving the RTS frame, the second station obtains the received power Pr, and replies to the CTS frame and carries the received power Pr in the CTS frame after a certain duration (e.g., SIFS duration).

And 704, after receiving the CTS frame, the first station reads out the received power Pr, calculates and updates the CCA threshold according to a formula of CCA (Pr ± Δ)/SINR, and uses the CCA threshold as the CCA threshold for the next data transmission of the first station. After a certain time duration (e.g., SIFS time duration), the first station transmits a data frame.

705, after receiving the data frame, the second station obtains the received power Pr, and after a certain time duration (for example, SIFS time duration), sends an ACK frame acknowledgement and carries the received power Pr in the frame, thereby completing the data transmission.

And 706, after receiving the ACK frame, the first station confirms that the data transmission is completed, reads out the received power Pr, calculates and updates the CCA threshold according to the formula CCA ═ Pr ± Δ/SINR, and uses the value as the CCA threshold for the next data transmission of the first station.

The method for transmitting data in a single-user scenario according to the embodiment of the present invention is described above with reference to fig. 1 to 7, and the method for transmitting data in a multi-user scenario is described below with reference to fig. 8 to 12.

FIG. 8 shows a system architecture diagram in a multi-user scenario in accordance with an embodiment of the present invention. As shown in fig. 8, the system may include an access point and a plurality of stations, where the access point may send a trigger frame to a group of stations, for triggering the group of stations to upload a data frame to the access point using a specified time-frequency resource. When allocating time-frequency resources, it is determined that the allocated channel state is idle at the access point side, but when the distance between the station and the access point is long, the channel state at the station side is inconsistent with that at the access point side, so in the prior art, all stations in a group of stations still need to perform CCA detection, and when it is determined that the channel state is idle, a data frame is transmitted to the access point. In the invention, when the distance between the access point and the station is relatively short, the consistency of the channel states of the station side and the access point side is relatively high, and the station with relatively short distance can directly upload the data frame without CCA detection by determining the distance, thereby achieving the purpose of reducing the system overhead.

A method 900 of an embodiment of the invention is described below, which method may be performed by a station, the method 900 including:

a station receives a trigger frame sent by an access point, wherein the trigger frame is used for instructing at least one station including the station to transmit a data frame to the access point;

920, the station determines whether the distance between the station and the access point is less than a preset distance according to the receiving power of the trigger frame;

930, when the distance between the station and the access point is smaller than the preset distance, the station transmits a data frame to the access point, wherein the station does not need to perform CCA detection.

In the embodiment of the invention, in the process of transmitting the data frame to the access point by the station, the station determines the receiving power of the trigger frame sent by the access point, and further determines whether the distance between the station and the access point is smaller than the preset distance or not according to the receiving power, if the distance between the station and the access point is smaller than the preset distance, the station is free from CCA detection, so that the system overhead is reduced.

Optionally, in 920, it is determined whether the distance between the station and the access point is smaller than a preset distance according to the received power, which may be determined whether the distance between the station and the access point is smaller than the preset distance according to a magnitude relationship between the received power and the preset power. For example, the access point may transmit the trigger frame with a fixed power, and the smaller the receiving power of the station receiving the trigger frame, the farther the access point is from the station. It can be specified that when the received power is greater than the preset power, the distance between the station and the access point is considered to be less than the preset distance. The embodiment of the present invention does not limit the preset power and the preset distance, and may be set according to the network condition.

Optionally, as an embodiment, in the method 900, the determining whether the distance between the station and the access point is smaller than a preset distance includes: determining the distance between the station and the access point according to the sending power and the receiving power, wherein the trigger frame comprises the sending power, and the sending power is the sending power of the access point for sending the trigger frame; determining whether the distance between the station and the access point is smaller than the preset distance.

Optionally, the determining a distance between the station and the access point according to the transmission power and the reception power includes: according to the formula Pr ═ Pt ═ d^-αAnd determining the distance between the station and the access point, wherein Pt represents the transmission power, Pr represents the reception power, d represents the distance between the station and the access point, and alpha represents a path loss factor.

Fig. 9 shows a schematic flow chart of a method of transmitting data according to a further embodiment of the invention. As shown in fig. 9, a flow chart for transmitting data in a multi-user scenario is shown. Specifically, the AP sends a trigger frame, where the trigger frame includes a transmission power Pt of the AP, and after receiving the trigger frame of the AP, the station obtains a reception power Pr, reads the transmission power Pt from the trigger frame, and reads the transmission power Pt according to a formula Pr ═ Pt × d^-αCalculating the distance d between the transmitting side and the receiving side; if d is less than or equal to dth (dth can be a distance threshold value and is used for judging whether the distance is a close distance, and the dth value can be specified by a protocol), the access point is considered to be closer to the station, and the station directly uploads the data frame without CCA detection. When d is larger than dth, the station needs to perform CCA detection and judges the busy-idle state of the channel; if the channel state is idle, transmitting data on a corresponding channel based on resources allocated by the trigger frame; and if the channel state is busy, the data is not sent to the access point, and the silence is kept.

Optionally, after determining whether the distance between the station and the access point is less than the predetermined distance, second information indicating a relationship between the distance between the access point and the station and the predetermined distance may be added to the data frame. The second information may be a bit representation, for example, it may be set that when the bit is assigned 1, the short distance is represented, and when the bit is assigned 0, the long distance is represented. Therefore, the access point can acquire the distance information between the stations and the access point according to the second information and schedule the stations according to the distance information.

Fig. 10 is a diagram illustrating a method of transmitting data according to another embodiment of the present invention. As shown in fig. 10, in a multi-user scenario, an access point sends a trigger frame, carries a sending power Pt in the trigger frame, and a station reads the sending power Pt and detects a receiving power Pr after receiving the trigger frame; then according to the formula Pr ═ Pt ═ d^-αCalculating the distance d between the receiving party and the receiving party; finally, the station judges whether the distance is a short distance or not according to the calculated distance d, and if the distance is the short distance, the station waits for a certain time length and sends an uplink data frame; otherwise, CCA detection is carried out, and the busy-idle state of the interception channel determines whether to send the uplink data frame.

The specific steps of the method of fig. 10 are described below.

1001, an AP sends a trigger frame (which may be denoted as a TF frame) in which a transmission power Pt is carried;

1002, after each STA receives the trigger frame, reading out the sending power Pt and detecting the receiving power Pr;

1003. each STA is according to the formula Pr ═ Pt × d^-αThe distance d is calculated and compared with a preset distance dth. As shown in fig. 10: since the STA1 determines that it is a short distance, it waits for a certain time period without performing CCA detection and transmits a data frame. The STA2 is in a long distance, performs CCA detection on the full channel corresponding to the allocated sub-channel to determine that the channel is idle, and waits for a certain period of time to transmit a data frame. The STA3 is in a long distance, and performs CCA detection on the full channel corresponding to the allocated sub-channel for a certain time, where the channel is busy.

1004, STA1, STA2 transmit upstream data frames on the allocated sub-channels and use 1bit in the data frames to characterize short distance (the bit value is 1 can be characterized as short distance communication, 0 can be characterized as long distance communication). STA3 remains silent because the channel status is busy.

1005, after receiving the data frames of STA1 and STA2, the AP replies a Block Acknowledgement (BA) frame to STA1 and STA2 after a certain time period.

Optionally, fig. 11 shows a method for transmitting data according to still another embodiment of the present invention, and fig. 11 shows a process that a station transmits data to an access point in a multi-user scenario, where the difference between fig. 11 and the method in fig. 10 is that the access point obtains information about distances from the stations to the access point according to history information, so as to schedule a remote station to perform uplink data transmission, and indicate that the group of stations is a remote station in an indication field in a trigger frame. I.e. instruct the group of stations to perform CCA detection. Wherein the history information may be information indicating the distance obtained by the access point from each station.

The specific steps of the method of fig. 11 are described below.

1101, the AP sends a trigger frame, in which an indication field (for example, may be denoted as switch, abbreviated as SW) is filled with 1 (the field value is 0: characterizing the near field communication, i.e. no CCA detection is needed; the field value is 1: characterizing the near field communication, i.e. CCA detection is needed);

1102, after receiving the trigger frame, the STA reads out that the value of the indication field is 1, which indicates that the STA needs to perform CCA detection;

1103, the STA1 and the STA3 perform CCA detection on the full channel corresponding to the sub-channel allocated to each STA for a certain time, and the channel is idle. The STA2 performs CCA detection on the full channel corresponding to the allocated sub-channel for a certain time, where the channel is busy.

1104, STA1, STA3 transmit uplink DATA on the assigned sub-channel. STA2 remains silent because the channel status is busy.

1105, after receiving the DATA of STA1 and STA3, the AP replies a BA frame to STA1 and STA3 after a certain period of time.

Optionally, in the method of fig. 11, the access point may also schedule a short-distance station to perform uplink data transmission according to history information, where the history information may be information that indicates a distance obtained from each station by the access point, and indicate, in an indication field in the trigger frame, that the group of stations is a short distance, that is, indicate that the group of stations does not need to perform CCA detection.

Optionally, fig. 12 shows a method for transmitting data according to another embodiment of the present invention, and in fig. 12, the access point may also respectively indicate, according to the history information, whether each station is in a close range in an indication field in the trigger frame, that is, indicate whether each station needs to perform CCA detection before transmitting uplink data.

1201, the AP sends a trigger frame, in which an indication field (for example, may be denoted as indication, abbreviated as IND) indicates whether each STA is in short-range communication;

1202, after each STA receives the trigger frame, reading the value of the indication field, and searching whether each STA is in a close range according to the value of the indication field, namely judging whether CCA detection is needed;

1203, the STA1 knows that the STA is in a close range, does not need to perform CCA detection, and waits for a certain time; if the STA2 knows that the STA is in a long distance and needs to perform CCA detection, the STA2 performs CCA detection on the full channel corresponding to the allocated sub-channel for a certain time, and the channel is idle; if the STA3 knows that the STA is in a long distance and needs to perform CCA detection, the STA3 performs CCA detection on the full channel corresponding to the allocated sub-channel for a certain time, and the channel is idle;

1204, STA1, and STA2 transmit uplink data on the allocated sub-channels. STA3 remains silent because the channel status is busy.

1205, after receiving the data of STA1 and STA2, the AP replies a BA frame to STA1 and STA2 after a certain time period.

The method of transmitting data is described in detail above with reference to fig. 1 to 12, and the station and the access point transmitting data are described in detail below with reference to fig. 13 to 20.

Fig. 13 is a schematic diagram of a station transmitting data according to an embodiment of the present invention. It should be understood that the station 1300 of fig. 13 is capable of implementing the various steps performed by the first station in fig. 1 to 7, and duplicate descriptions are appropriately omitted for the sake of brevity, and the station 1300 includes:

a sending module 1310, configured to send a first frame to a second station;

a first determining module 1320, configured to determine a first received power, where the first received power is a received power of the first frame received by the second station;

a second determining module 1330, configured to determine a first clear channel assessment CCA threshold value according to the first receiving power;

a transmitting module 1340 configured to transmit a first data frame to the second station based on the first CCA threshold value.

The station firstly determines first receiving power of a second station for receiving a first frame, further determines a first CCA threshold value according to the first receiving power, and transmits a first data frame to the second station based on the first CCA threshold value, so that the CCA threshold value can be dynamically adjusted according to the current network condition, and the data transmission efficiency is improved.

Fig. 14 is a schematic diagram of a station transmitting data according to an embodiment of the present invention. It should be understood that the station 1400 of fig. 14 is capable of implementing the various steps performed by the second station in fig. 1-7, and duplicate descriptions are appropriately omitted for the sake of brevity, and the station 1400 includes:

a receiving module 1410, configured to receive a first frame sent by a first station;

a determining module 1420 configured to determine a first reception power for receiving the first frame;

a sending module 1430, configured to send a second frame to the first station, where the second frame includes the first receiving power;

the receiving module 1410 is further configured to receive a first data frame transmitted by the first station based on a first CCA threshold value, where the first CCA threshold value is determined by the first station according to the first receiving power.

The station firstly determines first receiving power for receiving a first frame sent by a first station, and carries the first receiving power in a second frame sent to the first station, so that the first station determines a first CCA threshold value according to the first receiving power, thereby dynamically adjusting the CCA threshold value according to a network condition and improving the efficiency of data transmission.

Fig. 15 is a schematic diagram of a station transmitting data according to an embodiment of the present invention. It should be understood that the station 1500 of fig. 15 is capable of implementing the various steps performed by the station in fig. 8-12, and duplicate descriptions are appropriately omitted for the sake of brevity, the station 1500 including:

a receiving module 1510, configured to receive a trigger frame sent by an access point, where the trigger frame is used to instruct at least one station including the station to transmit a data frame to the access point;

a determining module 1520, configured to determine whether a distance between the station and the access point is smaller than a preset distance according to the received power for receiving the trigger frame;

a transmitting module 1530, configured to transmit a data frame to the access point when the distance between the station and the access point is smaller than the preset distance, where the station does not need to perform CCA detection.

Fig. 16 is a schematic diagram of a station transmitting data according to an embodiment of the present invention. It should be understood that station 1600 of fig. 16 is capable of implementing the various steps performed by the access point in fig. 8-12, with duplicate description omitted where appropriate for the sake of brevity, access point 1600 including:

a determining module 1610 configured to determine a first set of sites;

a sending module 1620, configured to send a first trigger frame to the first group of stations, where the first trigger frame is used to instruct the first group of stations to transmit data to the access point, the first trigger frame includes first information, and the first information is used to instruct each station in the first group of stations to determine whether a distance between the access point and each station is less than a preset distance, so that the each station determines whether to perform CCA detection according to the first information, where a station with a distance between the access point and the station that is less than the preset distance does not need to perform CCA detection.

Fig. 17 is a schematic diagram of a station transmitting data according to an embodiment of the present invention. It should be understood that the station 1700 of fig. 17 is capable of implementing the various steps performed by the first station in fig. 1 to 7, and duplicate descriptions are appropriately omitted for the sake of brevity, and the station 1700 includes:

a memory 1710 for storing programs;

a transceiver 1720 for transmitting a first frame to a second station;

a processor 1730 configured to execute a program in memory 1710, the processor 1730 configured to determine a first receive power at which the first frame is received by the second station when the program is executed; determining a first Clear Channel Assessment (CCA) threshold value according to the first receiving power;

the transceiver 1720 is further configured to transmit a first data frame to the second station based on the first CCA threshold value.

Fig. 18 is a schematic diagram of a station transmitting data according to an embodiment of the present invention. It should be understood that the station 1800 of fig. 18 is capable of implementing the various steps performed by the second station in fig. 1-7, with duplicate descriptions omitted where appropriate for the sake of brevity, the station 1800 including:

a memory 1810 for storing programs;

a transceiver 1820 configured to receive a first frame transmitted by a first station;

a processor 1830 configured to execute the program in memory 1810, the processor 1830 configured to determine a first receive power at which to receive the first frame when the program is executed;

the transceiver 1820 is further configured to transmit a second frame to the first station, where the second frame includes the first received power; receiving a first data frame transmitted by the first station based on a first CCA threshold value, wherein the first CCA threshold value is determined by the first station according to the first receiving power.

Fig. 19 is a schematic diagram of a station transmitting data according to an embodiment of the present invention. It should be understood that the station 1900 of fig. 19 is capable of implementing the various steps performed by the station in fig. 8 to 12, and duplicate descriptions are appropriately omitted for the sake of brevity, and the station 1900 includes:

a memory 1910 for storing programs;

a transceiver 1920 configured to receive a trigger frame sent by an access point, where the trigger frame is used to instruct at least one station including the station to transmit a data frame to the access point;

a processor 1930 that executes the program in memory 1910, wherein when the program is executed, the processor 1930 is configured to determine whether a distance between the station and the access point is less than a preset distance according to a received power at which the trigger frame is received;

the transceiver 1920 is further configured to transmit a data frame to the access point when the distance between the station and the access point is smaller than the preset distance, where the station does not need CCA detection.

Fig. 20 is a schematic diagram of an access point for transmitting data according to an embodiment of the present invention. It should be understood that the station 2000 of fig. 20 is capable of implementing the various steps performed by the access point in fig. 8-12, and duplicate descriptions are appropriately omitted for the sake of brevity, the access point 2000 including:

a memory 2010 for storing a program;

a processor 2030 configured to execute a program in memory 2020, wherein when the program is executed, processor 2030 is configured to determine a first set of sites;

a transceiver 2020, configured to send a first trigger frame to the first set of stations, where the first trigger frame is used to instruct the first set of stations to transmit data to the access point, and the first trigger frame includes first information, where the first information is used to instruct each station in the first set of stations to determine whether a distance between the access point and each station is less than a preset distance, so that the stations determine whether to perform CCA detection according to the first information, where stations whose distance between the access point and each station is less than the preset distance do not need to perform CCA detection.

Additionally, the terms "system" and "network" are often used interchangeably herein. The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be understood that in the present embodiment, "B corresponding to a" means that B is associated with a, from which B can be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may be determined from a and/or other information.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be embodied in electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described in a functional general in the foregoing description for the purpose of illustrating clearly the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the unit is only one logical functional division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may also be an electric, mechanical or other form of connection.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment of the present invention.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention essentially contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

Technical features and descriptions in one embodiment above can be understood and applied to other embodiments for brevity and clarity of the application document, and are not described in detail in other embodiments.

While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method of transmitting data, comprising:

a first station sends a first frame to a second station;

the first station determines a first receiving power, wherein the first receiving power is the receiving power of the second station for receiving the first frame;

the first station determines a first Clear Channel Assessment (CCA) threshold value according to the first receiving power;

the first station transmits a first data frame to the second station based on the first CCA threshold value;

the first station determines a first CCA threshold value according to the first received power, including:

the first station determines the first CCA threshold according to a ratio between the first received power and a target signal to interference noise ratio SINR threshold, where the target SINR threshold represents a threshold of SINR corresponding to a data frame transmitted between the first station and the second station.

2. The method of claim 1, wherein the first station determining the first received power comprises:

the first station receives a second frame sent by the second station, wherein the second frame comprises the first receiving power;

and the first station determines the first receiving power according to the second frame.

3. The method of claim 1 or 2, wherein the method further comprises:

and the first station determines the target SINR threshold value, wherein the target SINR threshold value is an SINR threshold value corresponding to a preset target modulation and coding strategy MCS level, or the target SINR threshold value is an SINR threshold value corresponding to a preset service quality QoS level.

4. The method of claim 1 or 2, wherein the method further comprises:

the first station receives an Acknowledgement (ACK) frame sent by the second station, wherein the ACK frame comprises second receiving power of the second station for receiving the first data frame;

the first station determines a second CCA threshold value according to the second receiving power;

and the first station transmits a second data frame to the second station based on the second CCA threshold value.

5. The method of claim 1 or 2, wherein the method further comprises:

the first station determines a third CCA threshold value, where the third CCA threshold value is a weighted average of at least one historical CCA threshold value, the at least one historical CCA threshold value is a corresponding CCA threshold value when a data frame is sent to the second station for the last N times, and N is greater than or equal to 1;

and the first station sends a third frame to the second station based on the third CCA threshold value.

6. The method of claim 2, wherein the first frame is a request to send RTS frame; the second frame is a Clear To Send (CTS) frame.

7. A method of transmitting data, comprising:

a second station receives a first frame sent by a first station;

the second station determines a first receiving power for receiving the first frame;

the second station sends a second frame to the first station, wherein the second frame comprises the first receiving power;

the second station receiving a first data frame transmitted by the first station based on a first CCA threshold value, wherein the first CCA threshold value is determined by the first station according to the first receiving power;

the first CCA threshold is determined by a ratio between the first received power and a target signal to interference noise ratio SINR threshold, where the target SINR threshold represents a threshold of SINR corresponding to data frames transmitted between the first station and the second station.

8. The method of claim 7, wherein the method further comprises:

the second station determines a second receiving power for receiving the first data frame;

the second station sends an ACK frame to the first station, where the ACK frame includes a second receiving power, so that the first station determines a second CCA threshold according to the second receiving power;

and the second station receives a second data frame sent by the first station based on the second CCA threshold value.

9. The method of claim 7 or 8, wherein the first frame is a request to send RTS frame; the second frame is a clear to send CTS frame.

10. A station for transmitting data, comprising:

a sending module, configured to send a first frame to a second station;

a first determining module, configured to determine a first received power, where the first received power is a received power of the second station receiving the first frame;

a second determining module, configured to determine a first CCA threshold according to the first received power;

a transmission module, configured to transmit a first data frame to the second station based on the first CCA threshold value;

the second determining module is specifically configured to determine the first CCA threshold according to a ratio between the first received power and a target SINR threshold, where the target SINR threshold represents a threshold of SINR corresponding to a data frame transmitted between the station and the second station.

11. The station of claim 10, wherein the first determining module is specifically configured to receive a second frame sent by the second station, and the second frame includes the first receiving power; determining the first received power according to the second frame.

12. The station of claim 11, wherein the second determining module is further configured to determine the target SINR threshold, where the target SINR threshold is an SINR threshold corresponding to a predetermined target modulation and coding scheme MCS level, or where the target SINR threshold is an SINR threshold corresponding to a predetermined quality of service QoS level.

13. The station according to claim 10 or 11, wherein the first determining module is further configured to receive an ACK frame sent by the second station, where the ACK frame includes a second receiving power at which the second station receives the first data frame; determining a second CCA threshold value according to the second receiving power of the first data frame; the transmitting module is further configured to transmit a second data frame to the second station based on the second CCA threshold value.

14. The station of claim 10 or 11, wherein the first determining module is further configured to determine a third CCA threshold value, the third CCA threshold value is a weighted average of at least one historical CCA threshold value, the at least one historical CCA threshold value is a CCA threshold value corresponding to the last N times of sending a data frame to the second station, and N is greater than or equal to 1, and the transmitting module is further configured to send a third frame to the second station based on the third CCA threshold value.

15. The station of claim 11, wherein the first frame is a request to send RTS frame; the second frame is a Clear To Send (CTS) frame.

16. A station for transmitting data, comprising:

a receiving module, configured to receive a first frame sent by a first station;

a determining module for determining a first receive power at which the first frame is received;

a sending module, configured to send a second frame to the first station, where the second frame includes the first receiving power;

the receiving module is further configured to receive a first data frame transmitted by the first station based on a first CCA threshold value, where the first CCA threshold value is determined by the first station according to the first reception power;

the first CCA threshold is determined by a ratio between the first received power and a target signal to interference noise ratio SINR threshold, where the target SINR threshold represents a threshold of SINR corresponding to data frames transmitted between the first station and the station.

17. The station of claim 16, wherein the determining module is further configured to determine a second receive power at which to receive the first data frame; the sending module is further configured to send an ACK frame to the first station, where the ACK frame includes a second receiving power, so that the first station determines a second CCA threshold according to the second receiving power; the receiving module is further configured to receive a second data frame sent by the first station based on the second CCA threshold value.

18. A station as claimed in claim 16 or 17, characterised in that the first frame is a request to send RTS frame; the second frame is a clear to send CTS frame.