CN112533252A

CN112533252A - Channel access method and station

Info

Publication number: CN112533252A
Application number: CN202011495936.8A
Authority: CN
Inventors: 李彦淳; 罗俊; 于健
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2016-03-11
Filing date: 2016-03-11
Publication date: 2021-03-19
Anticipated expiration: 2036-03-11
Also published as: CN107182076B; CN107182076A; CN112533252B

Abstract

The embodiment of the invention discloses a channel access method and a station, wherein the channel access method comprises the following steps: when a station receives a PPDU (direct current packet) in a target channel, detecting whether the PPDU is an uplink PPDU, and if the PPDU is the uplink PPDU, measuring an RSSI (received signal strength indicator) 1 based on a first signal in the PPDU; acquiring a first basic service set identifier in the PPDU, measuring an RSSI2 by the station based on a second signal in the PPDU, comparing whether the first basic service set identifier is consistent with a second basic service set identifier of the station, and if not, determining whether the competitive access of a target channel can be carried out according to an RSSI 2; if so, the station contends to access the target channel; the station determines whether the end time of accessing the target channel can exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU according to the RSSI 1. By adopting the embodiment of the invention, not only can the interference on the transmission of the uplink PPDU be avoided, but also the interference on the transmission of the downlink PPDU adjacently transmitted by the uplink PPDU can be avoided.

Description

Channel access method and station

Technical Field

The present invention relates to the field of wireless network technologies, and in particular, to a channel access method and a station.

Background

Current wireless local area networks often have multiple Basic Service Sets (BSSs), where each BSS includes one or more Stations (STAs), and of course, some BSSs may also include an Access Point (AP), for example: all BSSs include an AP, or only some BSSs include an AP. A STA may associate with an AP in the BSS to which the STA belongs, or may associate with APs in other BSSs, through which the STA performs network transmissions, each BSS having a unique basic service set identifier, and all stations belonging to the BSS having the basic service set identifier of the BSS.

In practical applications, it is common that multiple BSSs operating on the same channel (i.e., multiple BSSs operating on the same channel and having different basic service set identifiers) overlap in coverage area, so as to form an Overlapping BSS (OBSS), i.e., the OBSS and another BSS or multiple BSSs have Overlapping coverage area on the same channel. For example: BSS1 and BSS2 use the same channel, and BSS1 and BSS2 have overlapping coverage areas on the same channel, then BSS1 is the OBSS of BSS2, or BSS2 is the OBSS of BSS1, and stations that are OBSS each other can use the same channel for data transmission.

As shown in fig. 1, assume that STA1 and STA2 are OBSS stations, AP1 is an access point associated with STA2, AP1 transmits a trigger frame, and STA2 transmits an uplink physical layer protocol data unit (PPDU) on a target channel according to an AP instruction. STA1, using the same target channel and with STA2 being an OBSS station, may receive the uplink PPDU. The STA1 may measure the signal strength of the PPDU, determine that the target channel is forbidden for spatial reuse when the measured signal strength is higher than a maximum spatial multiplexing threshold, and determine that the target channel is allowed for spatial reuse and access the target channel when the measured signal strength is lower than the maximum spatial multiplexing threshold.

The prior art can only ensure that STA1 does not interfere with the uplink transmission of STA2 to AP1, but cannot protect the reception of STA2, for example, STA2 needs to receive the acknowledgement frame sent by the AP.

Disclosure of Invention

Embodiments of the present invention provide a channel access method and a station, which may not only ensure that interference is not generated for transmission of an uplink PPDU, but also ensure that interference is not generated for transmission of a downlink PPDU that is adjacently transmitted by the uplink PPDU.

A first aspect of an embodiment of the present invention provides a channel access method, which may include:

when a station receives a physical layer protocol data unit (PPDU) in a target channel, detecting whether the PPDU is an uplink PPDU;

if the uplink PPDU exists, the station measures a first Received Signal Strength (RSSI 1) based on a first Signal in the PPDU, and the first Signal is sent in a target frequency domain resource of the target channel;

the station acquires a first basic service set identifier in the PPDU preamble signal;

the station measures a second received signal strength RSSI2 based on a second signal in the PPDU, the frequency domain resource used by the second signal being all or part of the target frequency domain resource;

the site comparing whether the first basic service set identifier is consistent with a second basic service set identifier of the site itself;

if not, the station determines whether the target channel can be accessed in a competition mode according to the RSSI 2;

if so, the station contends to access the target channel;

the station determines whether the end time of the access target channel can exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU according to the RSSI 1. In this way, the station determines whether the target channel can be accessed in a competitive manner through RSSI2, and if so, the target channel can be accessed in a competitive manner for spatial reuse, and further, the station determines whether the end time of accessing the target channel can exceed the start time of the downlink PPDU transmission adjacent to the uplink PPDU through RSSI1, that is, determines whether the station will generate interference on receiving the downlink PPDU, so that in the spatial reuse process, not only the interference on the uplink PPDU transmission is guaranteed, but also the interference on the downlink PPDU transmission is guaranteed, meanwhile, the station listening time can be reduced, and the station energy is saved.

Optionally, the determining, by the station according to the RSSI2, whether the contention access of the target channel can be performed specifically includes:

if the RSSI2 is less than the second threshold and the station does not receive the trigger frame for triggering the uplink PPDU to transmit, the station determines that the contention access of the target channel can be performed;

if the RSSI2 is less than the second threshold and the received signal strength of the trigger frame received by the station for triggering the uplink PPDU to transmit is less than the fourth threshold, the station determines that the contention access of the target channel can be performed. Thus, whether the station can cause interference to the uplink PPDU transmission is determined according to the received signal strength of the trigger frame.

Based on the first aspect, in a first possible implementation manner of the first aspect, the first signal includes a Legacy Short Training Field (L-STF) and a Legacy Long Training Field (L-LTF) in an uplink PPDU preamble;

the second signal includes at least one of a High efficiency Short Training Field (HE-STF), a High efficiency Long Training Field (HE-LTF), and a High efficiency DATA Field (HE-DATA) in the uplink PPDU.

Based on the first aspect, in a second possible implementation manner of the first aspect, the downlink PPDU includes an Acknowledgement frame (ACK) or a Multi-block Acknowledgement (MU-BA) for the uplink PPDU.

Based on the first aspect, or the first possible implementation manner of the first aspect, or the second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the determining, by the station, whether contention access to the target channel is possible according to the RSSI2 includes:

if the RSSI2 is greater than the second threshold, the station determines that the contention access of the target channel cannot be performed; i.e. spatial reuse is not possible;

if the RSSI2 is less than the second threshold, the station determines that the target channel can be accessed in a contention mode, i.e., spatial reuse can be performed. In this way, the comparison between the RSSI2 and the second threshold may determine whether the uplink PPDU transmission will cause interference to the station for transceiving data, so as to determine whether to perform spatial sharing within the uplink PPDU transmission time.

Based on the third possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the determining, by the station according to the RSSI1, whether the end time of the access target channel can exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU includes:

if the RSSI1 is less than the first threshold, the station determines that the end time of accessing the target channel can exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU;

if the RSSI1 is greater than the first threshold, the station determines that the end time of accessing the target channel cannot exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU. In this way, the RSSI1 is compared with the first threshold value to determine the interference strength between the station and the station transmitting the uplink PPDU, so as to further determine whether the station transmitting and receiving data will cause interference to the station transmitting the uplink PPDU for receiving the downlink PPDU.

Based on the first aspect, in a fifth possible implementation manner of the first aspect, a station contends for access to a target channel, including:

the station detects the signal intensity of a signal carried by a target channel;

and if the signal intensity is smaller than the third threshold value, the station contends to access the target channel. Because all stations which are OBSS stations with the station sending the uplink PPDU compete to access the target channel for spatial reuse, in order to ensure the transmission quality of the target channel carrying signal, the signal strength of the carrying signal cannot be too large, and when the stations compete to access the target channel, the stations determine whether to compete to access and ensure the transmission quality of the target channel carrying signal by detecting the signal strength of the target channel carrying signal.

Optionally, if the signal strength is greater than the third threshold, the station suspends backoff until the uplink PPDU transmission ends or suspends backoff until a time determined by a preset offset after the uplink PPDU transmission ends.

In a sixth possible implementation manner of the first aspect, based on the first aspect, the method further includes:

a station receives a first indication frame, wherein the first indication frame comprises a target field used for indicating a maximum allowable backoff threshold value, the first indication frame comprises a beacon frame or a management frame, and the maximum allowable backoff threshold value is used for indicating the maximum backoff times of the station;

the station contends to access the target channel, including:

the station generates a backoff random value, wherein the backoff random value belongs to a preset range;

and the station performs backoff based on the backoff random value, and if the backoff is completed within the allowed range of the maximum allowed backoff threshold value, the station accesses the target channel. The maximum allowable backoff threshold value is indicated, so that the number of stations which compete to access the target channel for space sharing is ensured, and the transmission quality of the target channel transmission signal is ensured.

In a seventh possible implementation manner of the first aspect, based on the sixth possible implementation manner of the first aspect, the target field includes a maximum allowed backoff threshold value; alternatively, the first and second electrodes may be,

the target field includes a reference value for indicating a maximum allowed backoff threshold value, where the maximum allowed backoff threshold value is determined by the reference value and a value of a preset field in the uplink PPDU, and the value of the preset field may be a coefficient. And limiting the number of stations for spatial reuse by multiple indication modes of the maximum allowable backoff threshold value.

In an eighth possible implementation manner of the first aspect, based on the seventh possible implementation manner of the first aspect, the method further includes:

if the station does not finish the backoff within the range allowed by the maximum allowed backoff threshold value, the station suspends the backoff until the end time related to the uplink PPDU;

and when the end time related to the uplink PPDU is reached, the station detects whether the target channel is idle, and if the target channel is idle, the backoff is recovered.

The end time related to the uplink PPDU includes a signal transmission end of the uplink PPDU, or an acknowledgement frame transmission end corresponding to the uplink PPDU, or an offset time added after the signal transmission end of the uplink PPDU. And further limiting the stations not completing backoff within the allowed range of the maximum allowed backoff threshold value, suspending backoff until the PPDU transmission is finished, and controlling the number of stations performing space sharing in the target channel.

Based on the first aspect, in a ninth possible implementation manner of the first aspect, the basic service set identifier is a service set Color, BSS Color, and the method further includes:

a station receives a second indication frame, wherein the second indication frame comprises a first Basic Service Set Identifier (BSSID) and a characteristic field for indicating the update of a BSS Color, and the characteristic field carries the updated BSS Color;

the station matches the first BSSID with a second BSSID of the station;

and if the matching is consistent, the station updates the second BSS Color to the updated BSS Color. The embodiment provides an update mode of BSS Color, which facilitates expansion of a local area network, and a station can still update the BSS Color according to BSSID.

Optionally, the uplink PPDU may further include a preset field, where the preset field is used to indicate a change of a beam direction for transmitting the first signal and transmitting the second signal;

before the station measures a second received signal strength RSSI2 based on a second signal in the PPDU, the method further includes:

if the station detects that the preset field indicates that the beam directions for transmitting the first signal and the second signal are different, the station measures the RSSI2 based on the second signal in the PPDU.

If the station detects that the preset field indicates that the beam directions for transmitting the first signal and the second signal are the same, determining whether the target channel can be accessed in a competition manner and whether the end time for accessing the target channel can exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU according to the RSSI1, and in this way, by adopting the preset field to indicate the change of the beam direction, determining whether to measure the RSSI2 through the field, so that the measurement time of the station can be reduced.

A second aspect of the invention provides a station, which may comprise:

a receiving module, configured to receive a physical layer protocol data unit PPDU on a target channel;

the processing module is used for detecting whether the PPDU is an uplink PPDU or not;

the processing module is further configured to, if the PPDU is an uplink PPDU, measure a first Received Signal Strength (RSSI 1) based on a first Signal in the PPDU, where the first Signal is sent in a target frequency domain resource of the target channel;

the processing module is further configured to acquire a first basic service set identifier in the PPDU preamble;

the processing module is further configured to measure a second received signal strength RSSI2 based on a second signal in the PPDU, where the frequency domain resource used by the second signal is all or part of the target frequency domain resource;

the processing module is further configured to compare whether the first basic service set identifier is consistent with a second basic service set identifier of the site;

if not, the processing module is further configured to determine whether contention access to the target channel can be performed according to the RSSI 2;

a channel access module, configured to access the target channel in a contention manner if the contention access of the target channel is enabled;

the processing module is further configured to determine whether an end time of accessing the target channel can exceed a start time of transmission of a downlink PPDU adjacent to the uplink PPDU according to the RSSI 1. In this way, the station determines whether the target channel can be accessed in a competitive manner through RSSI2, and if so, the target channel can be accessed in a competitive manner for spatial reuse, and further, the station determines whether the end time of accessing the target channel can exceed the start time of the downlink PPDU transmission adjacent to the uplink PPDU through RSSI1, that is, determines whether the station will generate interference on receiving the downlink PPDU, so that in the spatial reuse process, not only the interference on the uplink PPDU transmission is guaranteed, but also the interference on the downlink PPDU transmission is guaranteed, meanwhile, the station listening time can be reduced, and the station energy is saved.

Based on the second aspect, in a first possible implementation manner of the second aspect, the first signal includes a Legacy Short Training Field (L-STF) and a Legacy Long Training Field (L-LTF) in the uplink PPDU preamble;

In a second possible implementation manner of the second aspect, the downlink PPDU includes an Acknowledgement (ACK) frame or a Multi-block Acknowledgement (MU-BA) frame for the uplink PPDU.

Based on the second aspect, or the first possible implementation manner of the second aspect, or the second possible implementation manner of the second aspect, in a third possible implementation manner of the second aspect, the determining, by the processing module, whether contention access to the target channel is possible according to the RSSI2 specifically includes:

if the RSSI2 is greater than a second threshold, the processing module determines that contention access for the target channel cannot be performed;

if the RSSI2 is smaller than the second threshold, the processing module determines that the contention access of the target channel is possible. In this way, the comparison between the RSSI2 and the second threshold may determine whether the uplink PPDU transmission will cause interference to the station for transceiving data, so as to determine whether to perform spatial sharing within the uplink PPDU transmission time.

Based on the third possible implementation manner of the second aspect, in a fourth possible implementation manner of the second aspect, the determining, by the processing module according to the RSSI1, whether the end time of accessing the target channel can exceed the start time of a transmission of a downlink PPDU adjacent to the uplink PPDU specifically includes:

if the RSSI1 is less than a first threshold, the processing module determines that the end time of accessing the target channel can exceed the start time of transmission of a downlink PPDU adjacent to the uplink PPDU;

if the RSSI1 is greater than the first threshold, the processing module determines that the end time of accessing the target channel cannot exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU. In this way, the RSSI1 is compared with the first threshold value to determine the interference strength between the station and the station transmitting the uplink PPDU, so as to further determine whether the station transmitting and receiving data will cause interference to the station transmitting the uplink PPDU for receiving the downlink PPDU.

In a fifth possible implementation manner of the second aspect, the contending, by the channel access module, for accessing the target channel specifically includes:

the channel access module detects the signal intensity of the signal carried by the target channel;

and if the signal intensity is smaller than a third threshold value, the channel access module contends to access the target channel. Because all stations which are OBSS stations with the station sending the uplink PPDU compete to access the target channel for spatial reuse, in order to ensure the transmission quality of the target channel carrying signal, the signal strength of the carrying signal cannot be too large, and when the stations compete to access the target channel, the stations determine whether to compete to access and ensure the transmission quality of the target channel carrying signal by detecting the signal strength of the target channel carrying signal.

In a sixth possible implementation manner of the second aspect, based on the second aspect, the receiving module is further configured to receive a first indication frame, where the first indication frame includes a target field for indicating a maximum allowed backoff threshold value, and the first indication frame includes a beacon frame or a management frame, and the maximum allowed backoff threshold value is used to indicate a maximum backoff number of the station;

the competing, by the channel access module, for accessing the target channel specifically includes:

the channel access module generates a backoff random value, and the backoff random value belongs to a preset range;

and the channel access module backs off based on the backoff random value, and if the backoff is finished within the allowed range of the maximum allowed backoff threshold value, the station accesses the target channel. The maximum allowable backoff threshold value is indicated, so that the number of stations which compete to access the target channel for space sharing is ensured, and the transmission quality of the target channel transmission signal is ensured.

In a seventh possible implementation manner of the second aspect, based on the sixth possible implementation manner of the second aspect, the target field includes a maximum allowed backoff threshold value; alternatively, the first and second electrodes may be,

Based on the seventh possible implementation manner of the second aspect, in an eighth possible implementation manner of the second aspect, the channel access module is further configured to suspend backoff until an end time associated with the uplink PPDU if the station does not complete backoff within a range allowed by the maximum allowed backoff threshold value;

and when the end time related to the uplink PPDU is reached, the channel access module detects whether the target channel is idle, and if the target channel is idle, the backoff is recovered. And further limiting the stations not completing backoff within the allowed range of the maximum allowed backoff threshold value, suspending backoff until the PPDU transmission is finished, and controlling the number of stations performing space sharing in the target channel.

Based on the second aspect, in a ninth possible implementation manner of the second aspect, the basic service set identifier is a service set Color, BSS Color, and the receiving module is further configured to receive a second indication frame, where the second indication frame includes the first basic service set identification, BSSID, and a feature field for indicating update of the BSS Color, and the feature field carries the updated BSS Color;

the processing module is further configured to match the first BSSID with a second BSSID of the station;

and the processing module is further used for updating the second BSS Color to the updated BSS Color if the matching is consistent. The embodiment provides an update mode of BSS Color, which facilitates expansion of a local area network, and a station can still update the BSS Color according to BSSID.

before the processing module measures a second received signal strength RSSI2 based on a second signal in the PPDU, the processing module further includes:

if the processing module detects that the preset field indicates that the beam directions for transmitting the first signal and the second signal are different, the station measures the RSSI2 based on the second signal in the PPDU.

If the processing module detects that the preset field indicates that the beam directions for transmitting the first signal and the second signal are the same, it is determined whether the target channel can be accessed in a competition manner and whether the end time for accessing the target channel can exceed the start time of transmission of a downlink PPDU adjacent to the uplink PPDU according to the RSSI1, and in this way, the change of the beam direction is indicated by the preset field, so that whether the RSSI2 is measured or not is determined by the field, and the measurement time of the station can be reduced.

A third aspect of the present invention provides a station comprising:

a radio frequency circuit for receiving a physical layer protocol data unit (PPDU) in a target channel;

the processor is used for detecting whether the PDU is an uplink PPDU or not;

the processor is further configured to measure, if the PPDU is an uplink PPDU, a first received signal strength RSSI1 based on a first signal in the PPDU, where the first signal is sent in a target frequency domain resource of the target channel;

the processor is further configured to obtain a first basic service set identifier in the PPDU preamble;

the processor is further configured to measure a second received signal strength, RSSI, 2 based on a second signal in the PPDU, the second signal using frequency domain resources that are all or part of the target frequency domain resources;

the processor is further configured to compare the first basic service set identifier with a second basic service set identifier of the site;

if not, the processor is further configured to determine whether contention access of the target channel can be performed according to the RSSI 2;

the processor is further configured to contend for access to the target channel if contention for access of the target channel is available;

the processor is further configured to determine whether an end time of accessing the target channel can exceed a start time of transmission of a downlink PPDU adjacent to the uplink PPDU according to the RSSI 1. In this way, the station determines whether the target channel can be accessed in a competitive manner through RSSI2, and if so, the target channel can be accessed in a competitive manner for spatial reuse, and further, the station determines whether the end time of accessing the target channel can exceed the start time of the downlink PPDU transmission adjacent to the uplink PPDU through RSSI1, that is, determines whether the station will generate interference on receiving the downlink PPDU, so that in the spatial reuse process, not only the interference on the uplink PPDU transmission is guaranteed, but also the interference on the downlink PPDU transmission is guaranteed, meanwhile, the station listening time can be reduced, and the station energy is saved.

Optionally, the determining, by the processor according to the RSSI2, whether contention access of the target channel can be performed specifically includes:

if the RSSI2 is less than the second threshold and the station does not receive the trigger frame for triggering the uplink PPDU to transmit, determining that the contention access of the target channel can be performed;

and if the RSSI2 is smaller than the second threshold and the received signal strength of the trigger frame received by the station for triggering the uplink PPDU to send is smaller than the fourth threshold, determining that the contention access of the target channel can be performed. Thus, whether the station can cause interference to the uplink PPDU transmission is determined according to the received signal strength of the trigger frame.

Based on the third aspect, in a first possible implementation manner of the third aspect, the first signal includes a legacy short training field L-STF and a legacy long training field L-LTF in an uplink PPDU preamble;

the second signal comprises at least one of a high-efficiency short training field HE-STF, a high-efficiency long training field HE-LTF and a high-efficiency DATA field HE-DATA in the uplink PPDU.

Based on the third aspect, in a second possible implementation manner of the third aspect, the downlink PPDU includes an Acknowledgement (ACK) frame or a Multi-block Acknowledgement (MU-BA) frame for the uplink PPDU.

Based on the third aspect, or the first possible implementation manner of the third aspect, or the second possible implementation manner of the third aspect, in a third possible implementation manner of the third aspect, the determining, by the processor, whether contention access of the target channel can be performed according to the RSSI2 specifically includes:

if the RSSI2 is greater than the second threshold, the processor determines that the contention access of the target channel cannot be performed; i.e. spatial reuse is not possible;

if RSSI2 is less than the second threshold, the processor determines that contention access for the target channel is possible, i.e., spatial reuse is possible. In this way, the comparison between the RSSI2 and the second threshold may determine whether the uplink PPDU transmission will cause interference to the station for transceiving data, so as to determine whether to perform spatial sharing within the uplink PPDU transmission time.

Based on the third possible implementation manner of the third aspect, in a fourth possible implementation manner of the third aspect, the determining, by the processor, whether the end time of the access target channel can exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU according to the RSSI1 specifically includes:

if the RSSI1 is less than the first threshold value, the processor determines that the end time of accessing the target channel can exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU;

if the RSSI1 is greater than the first threshold, the processor determines that the end time of accessing the target channel cannot exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU. In this way, the RSSI1 is compared with the first threshold value to determine the interference strength between the station and the station transmitting the uplink PPDU, so as to further determine whether the station transmitting and receiving data will cause interference to the station transmitting the uplink PPDU for receiving the downlink PPDU.

Based on the third aspect, in a fifth possible implementation manner of the third aspect, the contending, by the processor, for accessing the target channel specifically includes:

the processor detects the signal strength of a signal carried by a target channel;

and if the signal strength is less than the third threshold value, the processor contends to access the target channel. Because all stations which are OBSS stations with the station sending the uplink PPDU compete to access the target channel for spatial reuse, in order to ensure the transmission quality of the target channel carrying signal, the signal strength of the carrying signal cannot be too large, and when the stations compete to access the target channel, the stations determine whether to compete to access and ensure the transmission quality of the target channel carrying signal by detecting the signal strength of the target channel carrying signal.

In a sixth possible embodiment according to the third aspect,

the radio frequency circuit is further configured to receive a first indication frame, where the first indication frame includes a target field for indicating a maximum allowed backoff threshold value, and the first indication frame includes a beacon frame or a management frame, and the maximum allowed backoff threshold value is used to indicate a maximum backoff number of stations;

the contention for accessing the target channel by the processor specifically includes:

the processor generates a backoff random value, wherein the backoff random value belongs to a preset range;

and the processor performs backoff based on the backoff random value, and if the backoff is completed within the allowed range of the maximum allowed backoff threshold value, the station accesses the target channel. The maximum allowable backoff threshold value is indicated, so that the number of stations which compete to access the target channel for space sharing is ensured, and the transmission quality of the target channel transmission signal is ensured.

In a seventh possible implementation manner of the third aspect, based on the sixth possible implementation manner of the third aspect, the target field includes a maximum allowed backoff threshold value; alternatively, the first and second electrodes may be,

Based on the seventh feasible implementation manner of the third aspect, in an eighth feasible implementation manner of the third aspect, if the station does not complete backoff within the range allowed by the maximum allowed backoff threshold value, the processor controls the station to suspend backoff until the end time associated with the uplink PPDU;

and when the end time related to the uplink PPDU is reached, the processor detects whether the target channel is idle, and if the target channel is idle, the backoff is recovered. And further limiting the stations not completing backoff within the allowed range of the maximum allowed backoff threshold value, suspending backoff until the PPDU transmission is finished, and controlling the number of stations performing space sharing in the target channel.

Based on the third aspect, in a ninth possible implementation manner of the third aspect, the basic service set identifier is a service set Color, BSS Color;

the radio frequency circuit receives a second indication frame, wherein the second indication frame comprises a first Basic Service Set Identifier (BSSID) and a characteristic field used for indicating updating of a BSS Color, and the characteristic field carries the updated BSS Color;

the processor matches the first BSSID with a second BSSID of the station;

and if the match is consistent, the processor updates the second BSS Color to the updated BSS Color. The embodiment provides an update mode of BSS Color, which facilitates expansion of a local area network, and a station can still update the BSS Color according to BSSID.

before the processor measures a second received signal strength RSSI2 based on a second signal in the PPDU, the processor further includes:

if the predetermined field is detected to indicate that the beam direction for transmitting the first signal and the second signal is different, the processor measures the RSSI2 based on the second signal in the PPDU.

In the embodiment of the invention, when a site receives a PPDU (direct memory access) on a target channel, whether the PPDU is an uplink PPDU is detected, if the PPDU is the uplink PPDU, a first basic service set identifier in a preamble signal of the PPDU is further acquired based on a first signal measurement RSSI1, based on a second signal measurement RSSI2, whether the first basic service set identifier is consistent with a second basic service set identifier of the site is compared, if the first basic service set identifier is not consistent with the second basic service set identifier of the site, whether the target channel can be accessed in a competition mode is determined according to RSSI2, if the target channel can be accessed in a competition mode, and whether the end time of accessing the target channel can exceed the transmission start time of the downlink PPDU is further determined according to RSSI1, so that the uplink PPDU transmission is not interfered, and the downlink PPDU transmission is not interfered.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, 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 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 schematic diagram of an application scenario provided in an embodiment of the present invention;

fig. 2 is a flowchart illustrating a channel access method according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of an uplink PPDU according to an embodiment of the present invention;

fig. 4 is a diagram of a channel access scenario provided in an embodiment of the present invention;

fig. 5 is a diagram of another channel access scenario provided in the embodiment of the present invention;

fig. 6 is a diagram illustrating another channel access scenario provided in an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a station according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of another station provided in the 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 derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The BSS Color in the embodiment of the present invention is an identifier with a small number of bits (e.g., only 3 bits or 4 bits) and is used to distinguish neighboring BSSs.

The basic service set in the embodiment of the present invention identifies the BSSID as an identifier having a large number of bits (typically 46 bits) and used for distinguishing adjacent BSSs.

The BSSID is not normally changed and the BSS Color can be updated.

The embodiment of the invention can be applied to a Wireless Local Area Network (WLAN), and the standard adopted by the WLAN at present is IEEE (Institute of Electrical and Electronics Engineers, Chinese) 802.11 series. The WLAN may include a plurality of basic service sets BSS, where a network node in a basic service set is a Station, the Station includes a Station AP in an Access Point class and a Station (Non-AP STA for short) in a Non-Access Point class, and each basic service set may include an AP and a plurality of Non-AP STAs associated with the AP.

And the access point type station is also called as a wireless access point or a hot spot, and the like. The AP is an access point for a mobile subscriber to enter a wired network, and is mainly deployed in a home, a building, and a campus, and typically has a coverage radius of several tens of meters to hundreds of meters, and may be deployed outdoors. The AP acts as a bridge connecting the network and the wireless network, and mainly functions to connect the wireless network clients together and then to access the wireless network to the ethernet. Specifically, the AP may be a terminal device or a network device with a WiFi (Wireless Fidelity, chinese) chip. Optionally, the AP may be a device supporting 802.11ax standard, and further optionally, the AP may be a device supporting multiple WLAN standards such as 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11 a.

A Non-Access Point (Non-AP STA) may be a wireless communication chip, a wireless sensor, or a wireless communication terminal. For example: the mobile phone supporting the WiFi communication function, the tablet computer supporting the WiFi communication function, the set top box supporting the WiFi communication function, the smart television supporting the WiFi communication function, the smart wearable device supporting the WiFi communication function, the vehicle-mounted communication device supporting the WiFi communication function and the computer supporting the WiFi communication function. Optionally, the STA may support the 802.11ax system, and further optionally, the STA supports multiple WLAN systems such as 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11 a.

Referring to fig. 1, a system diagram of a typical WLAN deployment scenario includes an AP and 4 STAs, where AP1 and STA2, STA3 and STA4 belong to one BSS (STA2, STA3 and STA4 are associated with AP 1), and STA1 belongs to another BSS, and each BSS has a basic service set identifier (bssid) for identifying the BSS and distinguishing it from neighboring BSSs.

Assuming that BSS to which AP1, STA2, STA3 and STA4 belong is BSS1, BSS to which STA1 belongs is BSS2, BSS1 and BSS2 are OBSS, and stations that are OBSS can use the same channel for data transmission, in order to solve the problem of fully utilizing channel resources, a concept of spatial reuse is proposed and studied, where spatial reuse is to perform data transmission on the same channel by stations that are OBSS at the same time.

In order to ensure the communication quality, during the spatial reuse process, data transmission of a station (such as STA1 in fig. 1) that subsequently competes for accessing the channel cannot interfere with a communicating station (such as station STA2 in fig. 1 sending an uplink PPDU to AP 1), and at the same time, STA1 also needs to ensure that its data transmission is not interfered by the uplink PPDU being transmitted by STA 2.

In the prior art, when STA1 needs to perform spatial reuse with STA2, the interference/noise signal condition of the station is considered:

the station STA1 listens to the channel, and when the interference/noise energy is found to exceed a predetermined threshold, for example, the interference/noise energy exceeds-62 dBm, the channel is determined to be busy;

or the station STA1 receives a physical layer Preamble (PHY Preamble), where the Preamble carries a BSS Color identifier, and the BSS Color identifier is the same as the BSS Color identifier of the station, and thus the station STA1 considers the packet to be the BSS packet. Since the AP in the local cell is communicating with other stations but cannot communicate with the local station, the local station indicates that the channel is busy within the duration carried by the preamble. The station can sleep in the time to save energy;

or the station STA1 receives a physical layer Preamble (PHY Preamble), where the Preamble carries the BSS Color of the BSS, and the BSS Color is different from the BSS Color of the station, and the packet is considered to be a packet from the OBSS station. If the signal strength of the packet is higher than the maximum spatial multiplexing threshold, the station indicates that the channel is busy within the duration carried by the preamble in order to protect the communication of the OBSS.

Or the station STA1 receives a physical layer Preamble (PHY Preamble), where the Preamble carries the BSS Color of the BSS, and the BSS Color is different from the BSS Color of the BSS, and thus the packet is considered to be a packet from the OBSS. If the signal strength of the packet is lower than the maximum spatial multiplexing threshold, it can be considered that the packet can be ignored by the station if the transmission of the station has no influence on the communication of the OBSS.

As can be seen from the above, in the process of determining whether to perform spatial reuse by STA1 according to the received data packet, only STA1 can be guaranteed not to interfere with uplink transmission of STA2 to AP 1. However, STA2 cannot be protected from receiving, and after STA2 sends an uplink PPDU to AP1, AP1 needs to return an acknowledgement frame to STA2 to confirm whether the reception is complete and correct, and when STA2 receives the acknowledgement frame sent by AP1, it is determined that the data transmission is correct, and no retransmission is needed.

In the embodiment of the present invention, a channel access manner is provided, and when an STA1 receives an uplink PPDU sent by an STA2 to an AP1, the STA1 may measure an RSSI1 according to a first signal in the uplink PPDU and measure an RSSI2 according to a second signal in the uplink PPDU. The first signal occupies a target frequency domain resource of a target channel, and the second signal occupies a part or all of the target frequency domain resource, for example, one of the subbands.

STA1 determines whether or not contention access of the channel is possible based on RSSI2, that is, whether or not spatial reuse is possible is determined, and if spatial reuse is possible, contention access is performed on the channel, and STA1 determines whether or not the end time of access to the channel can exceed the transmission start time (e.g., ACK) of the downlink PPDU adjacent to the uplink PPDU based on RSSI 1. The mode of the invention not only can ensure that the transmission of the uplink PPDU is not interfered, but also can ensure that the downlink PPDU is not interfered.

The channel access method provided by the embodiment of the present invention will be described and explained with reference to fig. 2 to fig. 6.

Fig. 2 is a schematic flow chart of a channel access method according to an embodiment of the present invention; as shown in fig. 2, the channel access method includes:

s200, when a site receives a physical layer protocol data unit (PPDU) in a target channel, detecting whether the PPDU is an uplink PPDU;

in the embodiment of the present invention, a station is an access station AP or a non-access station, as shown in fig. 1, the station is a non-access station STA1, and STA1 and STA2 are OBSS stations; as shown in fig. 4, the station is an access-type station AP1, and the AP1 and STA2 are also OBSS stations.

The PPDU may be an uplink data packet sent on a target channel by a station that is an OBSS with the station, and therefore, when the station receives the PPDU on the target channel, it needs to detect whether the PPDU is an uplink PPDU and is triggered transmission, where the triggered transmission is a data packet transmitted after the OBSS station receives a trigger frame.

As shown in fig. 3, which is a schematic structural diagram of a PPDU according to an embodiment of the present invention, as shown in the figure, the PPDU includes a physical Preamble PHY Preamble and a data part (high efficiency data HE-Payload or physical data PHY-Payload), where the Preamble part includes a basic service set identifier (e.g., BSS Color) of a station that transmits the uplink PPDU and a Duration of the Preamble.

It should be noted that, as shown in fig. 3, the Preamble includes a conventional Preamble (L-Preamble) and a High-efficiency Preamble, and the High-efficiency Preamble includes a High-efficiency signaling a (HE-SIGA) part, a High-efficiency signaling B (HE-SIGB) part, a High-efficiency short training field HE-STF, and a High-efficiency long training field HE-LTF, where HE-STF and HE-LTF are transmitted in sub-channel resources, and other fields in the Preamble are transmitted in non-sub-channel resources (e.g., full-band resources), that is, other fields in the Preamble are transmitted in target frequency domain resources of a target channel, and HE-STF, HE-LTF, and the data part use partial channel resources of the target frequency domain resources.

As shown in fig. 4, taking a station as an access-type station as an example, the AP1 and the STA2 are OBSS stations, the AP2, the STA2, the STA3, and the STA4 belong to one BSS, and the AP1 belongs to another BSS. The AP2 sends a trigger frame, and further, the AP2 generates RXVECTOR (received vector) based on basic transmission parameter indication information such as the number of HE-LTF symbols included in the trigger frame, the spatial multiplexing stream configuration, Modulation and Coding Scheme (MCS), Cyclic Prefix (CP) length, transmission time, RU information (subcarrier set used in frequency domain), whether Space-time block Coding (STBC) is used, and the like.

After the STA2 receives the trigger frame, the STA2 transmits an uplink PPDU according to the indication information in the trigger frame. It should be noted that the flow of receiving the uplink PPDU by the AP2 is as follows:

after the AP2 sends the trigger frame, the uplink receive timer is set. Before the uplink receive timer expires, if the AP receives the physical preamble of the uplink PPDU, the physical layer PHY of the AP will measure the received signal strength RSSI 1. Meanwhile, the physical layer PHY reports the activity to a Media Access Control (MAC) layer through a PHY-cca indication primitive.

The physical layer PHY of the AP2 determines the format of the received PPDU according to the preamble, and if the received PPDU is an uplink PPDU and is a triggered transmission and the BSS color is consistent with the BSS color of the AP2, the AP2 cancels the uplink reception timer.

In the embodiment of the invention, an implementation manner of determining uplink and transmitting triggered PPDU is that Length in L-SIG in the PPDU preamble modulo 1 after 3, DL/UL bit in HE-SIG is set as UL, and triggered bit (or format bit for distinguishing triggered uplink transmission from other transmission) is set as triggered, and then the PPDU is called 'HE Trigger-based UL PPDU'.

The BSS color in the uplink PPDU preamble is consistent with the BSS color of the AP2, and the AP2 receives the uplink PPDU through receiving vector RXVECTOR information based on triggering. Specifically, channel estimation, including fine synchronization and Automatic Gain Control (AGC) adjustment, may be performed according to the HE-STF in the received uplink PPDU.

In the embodiment of the present invention, the AP2 obtains the number of HE-LTF symbols, and the specific obtaining manner may include the following four implementation manners, and implementation 1 is that the AP2 may obtain the number of HE-LTF symbols in the uplink PPDU according to the number of HE-LTF symbols received in RXVECTOR based on triggering. Implementation 2, the AP2 may also obtain the number of HE-LTF symbols in the uplink PPDU according to the number of spatial streams received RXVECTOR based on the trigger. And 3, the AP2 can also obtain the number of HE-LTF symbols in the uplink PPDU according to the number of the space streams carried in the HE-SIG-A in the trigger-based reception RXVECTOR. And 4, the AP2 can also obtain the number of HE-LTF symbols in the uplink PPDU according to the number of HE-LTF symbols carried in the HE-SIG-A in the trigger-based reception RXVECTOR. It should be noted that the subsequent information (including the CP length of HE-LTF and the symbol length of HE-LTF) can also be obtained in one of the 4 ways described above.

Further, the AP2 obtains the CP length of the HE-LTF and the symbol length (2x or 4x or 1x or other) of the HE-LTF according to the trigger receiving RXVECTOR, and the obtaining manner may refer to one of the above four manners. The AP can obtain the HE-LTF signal strength RSSI2 according to the number of HE-LTF symbols, the CP length of the HE-LTF and the symbol length of the HE-LTF.

Since HE-LTF and HE-Data are transmitted with the same spatial pattern (precoded or beamformed), the AP may optionally derive the HE-Data signal strength from the HE-LTF, i.e., the HE-Data signal strength is also RSSI 2. The AP2 may measure HE-Data to obtain HE-Data signal strength.

After the AP2 receives the uplink PPDU, the AP2 transmits an acknowledgement frame at the end time of the uplink PPDU or at a predetermined end time after a Short Inter-frame Space (SIFS) interval.

It should be noted that the BSS Color carried in the PPDU refers to a BSS Color of an AP associated with the STA that sends the uplink PPDU or a BSS Color of an AP for uplink transmission of the STA.

As shown in fig. 4, a station AP1 (i.e., the station of the present invention) that is an OBSS with respect to the uplink PPDU receives the PPDU signal on a target channel, and performs decoding check on L-SIG, R-L-SIG, HE-SIG-a, and HE-SIG-B in a preamble signal, and if the check is correct, it needs to further detect whether the PPDU is an uplink PPDU and is triggered for transmission. A PPDU realizing method for detecting and judging uplink and transmitting triggered PPDU is that Length in L-SIG in the PPDU preamble is 1 after 3, DL/UL bit in HE-SIG is set as UL, triggered bit (or called format bit for distinguishing triggered uplink transmission from other transmission) is set as triggered, then the PPDU is uplink triggered PPDU.

S201, if the channel is an uplink PPDU, the station measures a first received signal strength RSSI1 based on a first signal in the PPDU, and the first signal is sent in a target frequency domain resource of the target channel;

in the embodiment of the present invention, the first signal is transmitted in a target frequency domain resource of a target channel, for example, a full band of the target channel, where the target frequency domain resource of the target channel is taken as an example of a 20MHZ bandwidth, the 20MHZ bandwidth has four sub-channels, and the first signal occupies the four sub-channels, such as a preamble signal L-STF, L-LTF in a PPDU. A station occupying each of the four sub-channels may receive the first signal.

Continuing with the example of fig. 4, after the AP1 receives the physical layer PHY preamble of the uplink PPDU, the physical layer PHY of the STA will measure a first received signal strength RSSI1 based on the first signal in the PPDU preamble. While the physical layer PHY of AP1 reports this activity to the MAC via the PHY-cca.

Optionally, the first signal is sent in a target frequency domain resource of a target channel, and further optionally, the first signal may be sent in a full band of the target channel by using L-STF, L-LTF, and L-STF in a preamble of an uplink PPDU. As shown in fig. 3, which is a schematic structural diagram of an uplink PPDU according to an embodiment of the present invention, L-STF and L-LTF in a preamble of the PPDU use full-band resource transmission. Note that RSSI1 may indicate full-band interference between AP1 and STA 2.

S202, the station acquires a first basic service set identifier in the PPDU preamble signal;

in the embodiment of the present invention, the basic service set identifier may be BSSID, or basic service set Color BSS Color, or other cell identifier, and the like, which is not limited herein, and the basic service set identifier is used to distinguish neighboring BSSs.

The station parses a first basic service set identifier (e.g., BSS Color) carried in the PPDU preamble, where the first basic service set identifier is usually in the HE-SIG field, and further optionally, matches the first basic service set identifier with a second basic service set identifier of the station itself, it should be noted that the step of matching the first basic service set identifier with the second basic service set identifier of the station itself may also be performed before subsequent channel access.

S203, the station measures a second received signal strength RSSI2 based on a second signal in the PPDU, and the frequency domain resource used by the second signal is all or part of the target frequency domain resource;

in this embodiment of the present invention, the station measures a second received signal strength RSSI2 based on a second signal in the uplink PPDU, where a frequency domain resource used by the second signal is all or part of a target frequency domain used by the first signal, and optionally, the second signal may be at least one of HE-STF, HE-LTF, and HE-DATA.

As shown in fig. 3, which is a schematic structural diagram of a PPDU according to an embodiment of the present invention, HE-STF, HE-LTF, and HE-DATA use subchannel frequency domain resource transmission, while L-STF, L-LTF use full-band resource transmission of a target channel, and bandwidth resources used by HE-STF, HE-LTF, and HE-DATA are portions of bandwidth resources used by L-STF and L-LTF. Continuing with the above example in which the target frequency domain resource of the target channel is 20MHZ bandwidth, alternatively, the second signal may be a frequency domain resource occupying only one of the subchannels.

As shown in fig. 4, the AP1 may calculate the second received signal strength RSSI2 based on at least one of HE-STF, HE-LTF, and HE-DATA in the uplink PPDU transmitted by the STA 2.

Optionally, the AP1 may calculate the RSSI2 based on the HE-LTF, and the specific calculation method may be divided into two cases, that is, the AP1 receives the trigger frame sent by the AP2, and the AP1 does not receive the trigger frame sent by the AP 2.

If the AP1 receives the trigger frame sent by the AP2, refer to the calculation method of the RSSI2 calculated by the AP2 in step S200. The AP2 transmits a trigger frame, and the AP1 receives the trigger frame, and generates a trigger frame-based reception RXVECTOR based on basic transmission parameter indication information such as STBC (received vector) based on the number of HE-LTF symbols included in the trigger frame, stream configuration for spatial multiplexing, modulation and coding scheme MCS, CP length, transmission time, RU information (subcarrier set used in frequency domain), and whether STBC is used.

The subsequent AP1 may calculate the RSSI2 based on the received RXVECTOR, and please refer to the method of calculating the RSSI2 by the AP2 in step S200, which is not described herein again.

If the AP1 does not receive the trigger frame sent by the AP2, the AP1 may obtain parameters such as the CP length of the HE-LTF, the symbol length (2x or 4x or 1x or other) of the HE-LTF, the number of HE-LTF symbols, and the like from the HE-SIG field in the uplink PPDU of fig. 3, and calculate the RSSI2 according to the obtained HE-LTF symbol parameters.

Optionally, the AP1 may also calculate the RSSI2 based on the received power/energy/Orthogonal Frequency Division Multiplexing cyclic prefix (OFDM-CP) signal time domain repetition characteristics of the HE-DATA in the uplink PPDU, and the like.

The RSSI2 is calculated in a non-limiting manner, and the RSSI2 may indicate the interference that the STA2 causes to the AP1 when transmitting data on a certain sub-channel of the target channel.

S204, the site compares whether the first basic service set identifier is consistent with a second basic service set identifier of the site;

in this embodiment of the present invention, a station compares whether a first basic service set identifier parsed from an uplink PPDU is consistent with a second basic service set identifier of the station (that is, a BSS identifier associated with the station), and if the station detects that a first basic service set identifier in a preamble of the uplink PPDU is not consistent with a second basic service set identifier of the station in a matching manner, it indicates that the uplink PPDU is an uplink data packet sent by an OBSS station, and if the station is not set by a Transmission Opportunity (TXOP) holder of a BSS to which the station belongs (Network Allocation Vector, NAV) or is not set by a NAV holder of the OBSS, the station may further determine whether spatial reuse is possible, so as to contend for access to the target channel.

S205, if the RSSI2 is not consistent, the station determines whether the target channel can be accessed in a competition mode or not according to the RSSI 2;

in this embodiment of the present invention, if the first basic service set identifier and the second basic service set identifier are not matched, the station determines whether contention access of the target channel is available according to the RSSI2, that is, determines whether spatial reuse is available, and it should be noted that, as shown in fig. 4, the start time of spatial reuse is the data part transmission time of the uplink PPDU, that is, the time of transmitting data using the sub-channel.

Optionally, if spatial reuse is possible, the AP1 may set the channel state to idle, or the MAC of the AP1 may resume channel backoff. The PHY layer PHY of the AP1 may transmit a PHY-cca.indication (idle), and the MAC of the AP1 may resume the Enhanced Distributed Channel Access (EDCA) backoff procedure after receiving the PHY-cca.indication (idle).

Optionally, the determining, by the station according to the RSSI2, whether contention access of the target channel can be performed includes:

if the RSSI2 is greater than a second threshold, the station determines that the contention access of the target channel cannot be performed;

if the RSSI2 is smaller than the second threshold, the station determines that the contention access of the target channel can be performed.

In the embodiment of the present invention, the RSSI2 is compared with the second threshold, and if the RSSI2 is greater than the second threshold, the station determines that the target channel cannot be accessed in a contention mode, and if the RSSI2 is less than the second threshold, the station determines that the target channel can be accessed in a contention mode. The size of the second threshold depends mainly on the interference that the station can tolerate if transmitting. For example, as shown in fig. 4, the size of the second threshold mainly depends on the fact that the AP1 can tolerate interference when the STA2 transmits uplink data if transmitting, and the STA2 is a half-duplex node, and only transmits and does not receive when the STA2 transmits an uplink PPDU.

Further optionally, the station may further determine whether to contend for accessing the target channel in combination with other conditions, for example, the station may determine whether to contend for accessing the target channel according to whether the trigger frame is received or the signal strength of the received trigger frame:

if the RSSI2 is less than the second threshold and the station does not receive the trigger frame (i.e., it indicates that the AP1 does not interfere with the reception of the AP 2), determining that the target channel can be accessed in a contention mode; alternatively, the first and second electrodes may be,

if the RSSI2 is less than the second threshold and the received signal strength of the trigger frame received by the station is relatively low (i.e., indicating that the interference caused by the AP1 on the AP2 is relatively low), it is determined that the target channel can be accessed competitively.

S206, if yes, the station contends to access the target channel;

in the embodiment of the present invention, if it is determined that the target channel can be accessed according to the RSSI2, the station contends to access the target channel for spatial reuse, as shown in the time axis diagram of fig. 4, the AP1 starts to backoff to contend to access the target channel for spatial reuse after an interval AIFS time period.

Optionally, the access method for the station to contend for accessing the target channel may include multiple methods, and two alternative embodiments are described as an example below:

in a first optional implementation manner, the contention access of the station to the target channel includes the following two steps:

step one, the site detects the signal intensity of a signal carried by the target channel;

and step two, if the signal intensity is smaller than a third threshold value, the station contends to access the target channel.

In the embodiment of the invention, when an STA receives a physical PHY preamble, if the detected format is HE-PPDU, Clear Channel Assessment (CCA) is carried out in an HE-Data stage, and whether the target Channel can be accessed in a competitive way is detected through CCA.

Optionally, one of the CCA detection manners is to detect the signal strength of a signal carried by a target channel, and since all OBSS stations belonging to the STA2 perform spatial reuse detection during the process of transmitting an uplink PPDU by the STA2, multiple stations may have already accessed the target channel, and in order to ensure signal transmission quality, in the embodiment of the present invention, a station detects the signal strength of a signal carried by a current target channel through a CCA detection technique, and if the signal strength is less than a third threshold, it is indicated that contention access may be performed, and the station performs backoff contention access to the target channel.

Optionally, if the signal strength is greater than the third threshold, the station suspends backoff until the transmission of the uplink PPDU is ended, or the station suspends backoff until a fixed offset is added after the transmission of the uplink PPDU is ended, where the size of the fixed offset is determined by a protocol, or the station suspends backoff until the transmission of an acknowledgment frame corresponding to the uplink PPDU is ended.

In a second optional implementation manner, in order to control the number of stations performing spatial reuse in the target channel, the embodiment may further include the following step S20:

s20, the station receives a first indication frame, where the first indication frame includes a target field for indicating a maximum allowed backoff threshold value, and the first indication frame includes a beacon frame or a management frame, and the maximum allowed backoff threshold value is used to indicate a maximum backoff number of the station;

in this embodiment of the present invention, as shown in fig. 4, in order to control the number of stations performing spatial reuse on a target channel, an AP2 sends a first indication frame, where the first indication frame may be a beacon frame or a management frame, and the first indication frame includes a target field for indicating a maximum allowed backoff threshold value, where the maximum allowed backoff threshold value is used to indicate a maximum backoff number of the station, for example, if the maximum allowed backoff threshold value is 16, the maximum backoff number of the station is indicated as 16.

Further optionally, the indication manner of the target field indicating the maximum backoff threshold value may include multiple manners, which is not limited in the present invention. For example, the target field may include the maximum threshold value, that is, the maximum threshold value is directly encapsulated in the target field, as shown in fig. 4, when the AP1 parses the target field, the maximum backoff threshold value may be obtained, or the target field may also include a reference value used for indicating a maximum allowed backoff threshold value, where the maximum backoff threshold value is determined by the reference value and a value of a preset field in the uplink PPDU, it should be noted that the preset field may include one or more fields, the value of the preset field may be a coefficient, the maximum backoff threshold value may be a product or an addition of the reference value and the system, and the specific calculation manner is various and may be preset.

Based on the first indication frame, the station contends to access the target channel, including the following four steps:

step one, the station generates a backoff random value, and the backoff random value belongs to a preset range;

and step two, the station performs backoff based on the backoff random value, and if the backoff is completed within the allowed range of the maximum allowed backoff threshold value, the station accesses the target channel.

Step three, if the station does not finish the backoff within the allowed range of the maximum allowed backoff threshold value, the station suspends the backoff until the end time related to the uplink PPDU;

and step four, when the end time related to the uplink PPDU is reached, the station detects whether the target channel is idle, and if the target channel is idle, the station resumes back-off.

The end time related to the uplink PPDU includes a signal transmission end of the uplink PPDU, or an acknowledgement frame transmission end corresponding to the uplink PPDU, or an offset time added after the signal transmission end of the uplink PPDU.

When the station AP1 detects that the allowed space is reused, the backoff is started, and the specific backoff method is as follows: a Carrier Sense Multiple Access (CSMA) backoff counter of a station generates a backoff random value, which falls within a preset range, for example, 0 to 63.

The station performs backoff based on the random backoff value, the random backoff value is reduced by 1 every time the station performs backoff, the maximum backoff number is indicated by the maximum backoff threshold value in the first indication frame, when the station backs off the maximum backoff number, the random backoff value still does not reach 0, the backoff is not completed, if the number of times the station backs off is less than or equal to the maximum backoff number, the random backoff value returns to 0, the backoff is completed, and when the station completes backoff, the station can access the target channel.

In the embodiment of the invention, if the station does not finish the backoff within the allowable range of the maximum allowable backoff number threshold value, the backoff is suspended. And detecting the busy and idle condition of a target channel when the end time related to the uplink PPDU is reached, and recovering the backoff if the channel is idle.

By the above manner, the number of stations performing spatial reuse on the target channel can be controlled, as shown in fig. 6, for example, when the random value generation range of a CSMA backoff counter of a station is 0 to 63, and the maximum allowed backoff threshold value is 16, according to the maximum allowed backoff threshold value, the probability that only 16/64 is 1/4 at most performs spatial reuse during transmission of STA 2.

The AP2 may control the expected number of stations performing spatial reuse by a maximum allowed backoff threshold value to avoid interference exceeding the OBSS allowed range. The AP can acquire the interference situation (interference fluctuation variance, interference power, wireless packet loss probability and the like) of the OBSS through AP-AP information interaction or AP-AC-AP information interaction.

As shown in fig. 6, that is, another schematic view of a channel access scenario provided in the embodiment of the present invention, as shown in the drawing, both the AP1 and the AP3 detect that spatial reuse is possible during STA2 transmission, but the AP2 may control the number of stations performing spatial sharing by indicating the maximum allowed backoff threshold value, for example, the AP2 may control any one of the AP1 and the AP3 to contend for accessing the target channel for spatial sharing.

As shown in the time-axis diagram of fig. 6, both the AP1 and the AP3 perform backoff, the AP1 performs backoff within the maximum allowed backoff threshold value, contends to access the target channel for spatial reuse, and the AP3 does not perform backoff within the maximum allowed backoff threshold value, so the AP3 suspends backoff until the PPDU transmission is finished, and performs backoff access after the interval AIFS.

S207, the station determines whether the end time of accessing the target channel can exceed the transmission start time of the downlink PPDU adjacent to the uplink PPDU according to the RSSI 1.

In this embodiment of the present invention, the station determines, according to the measured RSSI1, whether the end time of accessing the target channel can exceed the transmission start time of a downlink PPDU adjacent to the uplink PPDU, where the downlink PPDU may be an ACK or an MU-BA replied to the uplink PPDU, and the frequency domain resource used by the downlink PPDU is not limited in the present invention, and may be a full-band frequency domain resource of the target channel, or a frequency domain resource of at least one sub-channel. As shown in fig. 4, RSSI1 may indicate interference between AP1 and STA2 at the target frequency domain resource.

Optionally, the determining, by the station according to the RSSI1, whether the end time of accessing the target channel can exceed the start time of transmission of a downlink PPDU adjacent to the uplink PPDU includes:

if the RSSI1 is less than a first threshold, the station determines that the end time of accessing the target channel can exceed the start time of transmission of a downlink PPDU adjacent to the uplink PPDU;

if the RSSI1 is greater than the first threshold, the station determines that the end time of accessing the target channel cannot exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU.

In the embodiment of the present invention, if the RSSI1 is less than the first threshold, it indicates that the interference between the station and the uplink PPDU is relatively small, and as shown in fig. 4, the RSSI1 is less than the first threshold, it indicates that the data received and transmitted by the AP1 does not cause strong interference to the STA2 receiving the downlink PPDU (for example, ACK/BA), and the end time of the AP1 accessing the target channel for spatial reuse may exceed the transmission start time of the downlink PPDU adjacent to the uplink PPDU. As shown in the time axis of fig. 4, the time for spatial reuse by the AP1 exceeds the start time of the ACK/BA transmission.

If the RSSI1 is greater than the first threshold, it indicates that the interference between the STA and the uplink PPDU is strong, and as shown in fig. 5, if the RSSI1 is greater than the first threshold, it indicates that the data received and transmitted by the AP1 causes strong interference to the STA2 receiving the downlink PPDU (for example, ACK/BA), and the end time of the AP1 accessing the target channel for spatial reuse cannot exceed the transmission start time of the downlink PPDU adjacent to the uplink PPDU. As shown in the time axis of fig. 5, the time for spatial reuse by the AP1 does not exceed the start time of ACK/BA transmission, and the channel is set busy during the ACK/BA transmission period.

Further optionally, the directions of the first signal and the second signal may be changed, for example, the first signal is sent omnidirectionally, and the second signal is sent omnidirectionally (as shown in fig. 3, a field signal sent by using the full-band frequency domain resource of the target channel is sent omnidirectionally, and a field signal sent by using one of the subchannel frequency domain resources is also sent omnidirectionally); or, the first signal is sent omnidirectionally, and the second signal is sent directionally (as shown in fig. 3, the field signal sent by using the full-band frequency domain resource of the target channel is sent omnidirectionally, and the field signal sent by using one of the subchannel frequency domain resources is sent directionally); or, the first signal is transmitted directionally, and the second signal is transmitted directionally (as shown in fig. 3, the field signal transmitted by using the full-band frequency domain resource of the target channel is transmitted directionally, and the field signal transmitted by using one of the subchannel frequency domain resources is also transmitted directionally). The invention adopts the preset field to indicate whether the beam direction of the first signal and the second signal is changed. Optionally, the Beam Change bit indication in the uplink PPDU is utilized.

As shown in fig. 4, if the AP1 detects that the received PPDU is an uplink PPDU and is a triggered transmission, and meanwhile, the first BSS identifier in the PPDU preamble is different from the second BSS identifier of the AP1, the AP1 is not set by the TXOP holder of the BSS or the AP1 is not set by the TXOP holder of the OBSS to NAV, during the measurement, the RSSI1 is smaller than the first threshold, the Beam Change bit is set to indicate that the Beam direction does not Change, and the second threshold is greater than or equal to the first threshold, the AP1 may determine that spatial reuse is possible directly according to the RSSI 38 1, and the end time of the spatial reuse may exceed the start time of downlink PPDU (ACK/BA) transmission. The AP1 may set the channel state to idle. The MAC of the STA may resume the channel backoff. The PHY of the STA may transmit a PHY-cca.indication (idle), and the MAC of the STA may resume the EDCA backoff procedure after receiving the PHY-cca.indication (idle). It should be noted that, if the second threshold is smaller than the first threshold, it indicates that spatial reuse is not possible.

If the AP1 detects that the received PPDU is an uplink PPDU and is a triggered transmission, and meanwhile, a BSS color in a PPDU preamble is different from a BSS color of the AP1, the AP1 is not set by a NAV of a TXOP holder of the BSS or the AP1 is not set by a NAV of a TXOP holder of an OBSS, and during a measurement process, the RSSI1 is greater than a first threshold value and the Beam Change bit is set to indicate a Beam direction Change, the AP1 needs to further measure the RSSI2, so as to determine whether to contend for accessing the target channel.

Further optionally, the basic service set identifier may be a basic service set Color, BSS Color, and the BSS Color of the basic service set BSS may be updated, so the channel access method of this embodiment may further include the following steps S206 to S208;

s208, the station receives a second indication frame, wherein the second indication frame comprises a first Basic Service Set Identifier (BSSID) and a characteristic field used for indicating the update of a BSS Color, and the characteristic field carries the updated BSS Color;

in the embodiment of the invention, the BSS Color of the station can be updated, the BSSID refers to the MAC address of the station, and the BSS is defined by the IEEE 802.11-1999 specification of the wireless local area network. This area uniquely defines each BSS. The BSSID is a locally administered IEEE MAC address, generated from an arbitrary encoding of 46 bits. The individual/group bit of the address is set to 0 and the universal/local address bit is set to 1. All STAs in a BSS store BSSIDs of APs in the BSS, and when a BSS Color of the AP in the BSS is updated, a second indication frame is sent, wherein the second indication frame comprises the first BSSID of the AP.

S209, the station matches the first BSSID with a second BSSID of the station;

in this embodiment of the present invention, when the station receives the second indication frame, the first BSSID is matched with the second BSSID of the station, and the second BSSID of the station is the BSSID of the AP associated with the station.

And S210, if the matching is consistent, the station updates the second BSS Color to the updated BSS Color.

In the embodiment of the present invention, if the matching matches, it indicates that the BSS Color of the AP associated with the station is updated, so that the station updates its own BSS Color.

The following describes a specific implementation of the station provided by the embodiment of the present invention with reference to fig. 7 to 8.

Referring to fig. 7, a schematic structural diagram of a station according to an embodiment of the present invention is shown in fig. 7, where the station according to the embodiment includes: a receiving module 100, a processing module 101 and a channel access module 102.

A receiving module 100, configured to receive a physical layer protocol data unit PPDU on a target channel;

optionally, the station is an access station AP or a non-access station, as shown in fig. 1, the station is a non-access station STA1, and STA1 and STA2 are OBSS stations; as shown in fig. 4, the station is an access-type station AP1, and the AP1 and STA2 are also OBSS stations.

A processing module 101, configured to detect whether the PPDU is an uplink PPDU;

the processing module 101 is further configured to, if the PPDU is an uplink PPDU, measure a first received signal strength RSSI1 based on a first signal in the PPDU, where the first signal is sent in a target frequency domain resource of the target channel;

optionally, the first signal includes L-STF, L-LTF in the uplink PPDU preamble. The first signal is transmitted in a target frequency domain resource of a target channel, for example, the L-STF in the uplink PPDU preamble signal, and the L-LTF is full-band transmission of the target channel.

The processing module 101 is further configured to acquire a first basic service set identifier in the PPDU preamble;

optionally, the basic service set identifier may be BSSID, or basic service set Color BSS Color, or other cell identifier, etc., and is not limited herein, the basic service set identifier is used to distinguish between adjacent BSSs.

The processing module 101 is further configured to measure a second received signal strength RSSI2 based on a second signal in the PPDU, the frequency domain resource used by the second signal being all or part of the target frequency domain resource;

optionally, the station measures a second received signal strength RSSI2 based on a second signal in the uplink PPDU, where a frequency domain resource used by the second signal is all or part of a target frequency domain used by the first signal.

Further optionally, the second signal may be at least one of HE-STF, HE-LTF, and HE-DATA, which use sub-channel transmission, and L-STF, L-LTF, which use full-band transmission of the target channel, and the bandwidth resources used by the HE-STF, HE-LTF, and HE-DATA are part of the bandwidth resources used by the L-STF, L-LTF.

The processing module 101 is further configured to compare whether the first basic service set identifier is consistent with a second basic service set identifier of the site;

the processing module 101 is further configured to determine whether contention access to the target channel is possible according to the RSSI2 if the first bss identifier is not consistent with the second bss identifier of the station;

specifically, optionally, the determining, by the processing module 101 according to the RSSI2, whether the contention access of the target channel can be performed specifically includes:

if the RSSI2 is greater than a second threshold, the processing module 101 determines that contention access to the target channel cannot be performed;

if the RSSI2 is smaller than the second threshold, the processing module 101 determines that the contention access of the target channel is possible.

A channel access module 102, configured to perform contention access on the target channel if contention access on the target channel is possible;

optionally, the access mode in which the channel access module 102 contends to access the target channel may include the following two optional implementations:

in a first optional implementation manner, the contending for access to the target channel by the channel access module 102 specifically includes:

the channel access module 102 detects the signal strength of the signal carried by the target channel;

if the signal strength is smaller than a third threshold, the channel access module 102 contends to access the target channel.

In a second optional implementation manner, the receiving module 100 of the station is further configured to receive a first indication frame, where the first indication frame includes a target field for indicating a maximum allowed backoff threshold value, where the first indication frame includes a beacon frame or a management frame, and the maximum allowed backoff threshold value is used to indicate a maximum backoff number of the station;

optionally, the target field includes the maximum allowed backoff threshold value; alternatively, the first and second electrodes may be,

the target field comprises a reference value used for representing the maximum allowable backoff threshold value, and the maximum allowable backoff threshold value is determined by the reference value and a value of a preset field in the uplink PPDU.

The contending, by the channel access module 102, for accessing the target channel specifically includes:

the channel access module 102 generates a backoff random value, and the backoff random value belongs to a preset range;

and the channel access module 102 performs backoff based on the backoff random value, and if the backoff is completed within the allowed range of the maximum allowed backoff threshold value, the station accesses the target channel.

The channel access module 102 is further configured to suspend backoff until an end time related to the PPDU transmission if the station does not finish backoff within the range of the maximum allowed backoff threshold value;

when the end time related to the PPDU transmission is reached, the channel access module 102 detects whether the target channel is idle, and if the target channel is idle, the backoff is resumed.

Optionally, the end time associated with the uplink PPDU includes a signal transmission end of the uplink PPDU, or an acknowledgement frame transmission end corresponding to the uplink PPDU, or an offset time added after the signal transmission end of the uplink PPDU.

The processing module 101 is further configured to determine whether an end time of accessing the target channel can exceed a start time of transmission of a downlink PPDU adjacent to the uplink PPDU according to the RSSI 1.

The determining, by the processing module 101 according to the RSSI1, whether the end time of accessing the target channel can exceed the start time of transmission of the downlink PPDU adjacent to the uplink PPDU specifically includes:

if the RSSI1 is smaller than a first threshold, the processing module 101 determines that the end time of accessing the target channel can exceed the start time of transmission of a downlink PPDU adjacent to the uplink PPDU;

if the RSSI1 is greater than the first threshold, the processing module 101 determines that the end time of accessing the target channel cannot exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU.

Further optionally, the directions of the first signal and the second signal may be changed, for example, the first signal is transmitted omnidirectionally, and the second signal is transmitted omnidirectionally; or the first signal is sent in an omnidirectional way, and the second signal is sent in a directional way; alternatively, the first signal is transmitted directionally and the second signal is transmitted directionally. The invention adopts the preset field to indicate whether the beam direction of the first signal and the second signal is changed. Optionally, the Beam Change bit indication in the uplink PPDU is utilized.

If the AP1 detects that the received PPDU is an uplink PPDU and is a triggered transmission, and meanwhile, a BSS color in a PPDU preamble is different from a BSS color of the AP1, the AP1 is not set by a NAV of a TXOP holder of the BSS or the AP1 is not set by a NAV of a TXOP holder of an OBSS, during a measurement process, the RSSI1 is smaller than a first threshold, the Beam Change bit is set to indicate that the Beam direction does not Change, the second threshold is greater than or equal to the first threshold, the AP1 may directly determine that spatial reuse can be performed according to the RSSI1, and an end time of the spatial reuse may exceed a start time of downlink PPDU (ACK/BA) transmission. The AP1 may set the channel state to idle. The MAC of the STA may resume the channel backoff. The PHY of the STA may transmit a PHY-cca.indication (idle), and the MAC of the STA may resume the EDCA backoff procedure after receiving the PHY-cca.indication (idle). It should be noted that, if the second threshold is smaller than the first threshold, it indicates that spatial reuse is not possible.

Further optionally, the basic service set identifier is a service set Color BSS Color, and the BSS Color of the station may be updated in the following manner:

the receiving module 100 is further configured to receive a second indication frame, where the second indication frame includes a first basic service set identifier BSSID and a feature field used for indicating that a BSS Color is updated, and the feature field carries an updated BSS Color;

the processing module 101 is further configured to match the first BSSID with a second BSSID of the station;

the processing module 101 is further configured to update the second BSS Color to the updated BSS Color if the matching is consistent.

It is understood that the specific implementation manner of each module in the above-mentioned station may further refer to the related description in the method embodiment.

Referring to fig. 8, a schematic structural diagram of another station according to an embodiment of the present invention is provided, where the station 1000 includes a processor 1010, a memory 1020, a baseband circuit 1030, a radio frequency circuit 1040, and an antenna 1050. The station may be STA1 shown in fig. 1 or AP1 shown in fig. 4 or AP1 or AP3 shown in fig. 6.

In particular, processor 1010 controls the operation of station 1000. Memory 1020 may include read-only memory and random-access memory and provides instructions and data to processor 1010, which may be a general-purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array, or other programmable logic device. A portion of the memory 1020 may also include non-volatile row random access memory (NVRAM). The baseband circuit 1030 is configured to synthesize a baseband signal to be transmitted, or decode a received baseband signal, for example, decode L-SIG, R-L-SIG, HE-SIG-a, and HE-SIG-B in a Preamble of an uplink PPDU. The radio frequency circuit 1040 is used to modulate a low frequency baseband signal to a high frequency carrier signal that is transmitted via the antenna 1050. The radio frequency circuitry is also used to demodulate the high frequency signals received by the antenna 1050 into a low frequency carrier signal. The various components of station 1000 are coupled together by a bus 1060, where bus system 1060 includes a power bus, a control bus, and a status signal bus, in addition to a data bus. For clarity of illustration, however, the various buses are designated as the bus system 1060 in the figure. It should be noted that the above description of the station structure can be applied to the following embodiments.

A radio frequency circuit 1040 configured to receive a physical layer protocol data unit PPDU on a target channel;

a processor 1010, configured to detect whether the PPDU is an uplink PPDU;

a processor 1010, configured to, if the PPDU is an uplink PPDU, measure a first received signal strength RSSI1 based on a first signal in the PPDU, where the first signal is sent in a target frequency domain resource of the target channel;

the processor 1010 is further configured to obtain a first basic service set identifier in the PPDU preamble;

the processor 1010 is further configured to measure a second received signal strength, RSSI, 2 based on a second signal in the PPDU, the second signal using all or part of the target frequency domain resources;

the processor 1010 is further configured to compare whether the first basic service set identifier is consistent with a second basic service set identifier of the site;

if the RSSI2 is not consistent with the target channel, the processor 1010 is further configured to determine whether contention access of the target channel is possible according to the RSSI 2;

the processor 1010 is further configured to contend for access to the target channel;

the processor 1010 is further configured to determine whether an end time of accessing the target channel can exceed a start time of a transmission of a downlink PPDU adjacent to the uplink PPDU according to the RSSI 1.

Optionally, the determining, by the processor 1010 according to the RSSI2, whether contention access of the target channel can be performed specifically includes:

if the RSSI2 is less than the second threshold and the station does not receive the trigger frame for triggering the uplink PPDU to transmit, the processor 1010 determines that the contention access of the target channel can be performed;

if the RSSI2 is less than the second threshold and the received signal strength of the trigger frame received by the station for triggering the uplink PPDU to transmit is less than the fourth threshold, the processor 1010 determines that the contention access of the target channel can be performed.

The first signal comprises a traditional short training field L-STF and a traditional long training field L-LTF in an uplink PPDU (P-channel indication unit) preamble signal;

The downlink PPDU includes an Acknowledgement (ACK) or a Multi-block Acknowledgement (MU-BA) for the uplink PPDU.

Optionally, the determining, by the processor 1010 according to the RSSI2, whether the contention access of the target channel can be performed specifically includes:

if RSSI2 is greater than the second threshold, processor 1010 determines that contention access for the target channel is not possible; i.e. spatial reuse is not possible;

if RSSI2 is less than the second threshold, processor 1010 determines that contention access for the target channel is available, i.e., spatial reuse is available.

The comparison between the RSSI2 and the second threshold may determine whether the uplink PPDU transmission will cause interference to the station for receiving and transmitting data, so as to determine whether to perform spatial sharing within the uplink PPDU transmission time.

Optionally, the determining, by the processor 1010 according to the RSSI1, whether the end time of the access target channel can exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU specifically includes:

if RSSI1 is less than the first threshold, processor 1010 determines that the end time of accessing the target channel can exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU;

if RSSI1 is greater than the first threshold, processor 1010 determines that the end time of accessing the target channel cannot exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU.

Optionally, the contention for accessing the target channel by the processor 1010 specifically includes:

processor 1010 detects the signal strength of the signal carried by the target channel;

and if the signal strength is less than the third threshold value, the processor contends to access the target channel.

Further optionally, if the signal strength is greater than the third threshold, the station suspends backoff until the end of the uplink PPDU transmission or suspends backoff until a time determined by a preset offset after the end of the uplink PPDU transmission.

Optionally, the radio frequency circuit 1040 is further configured to receive a first indication frame, where the first indication frame includes a target field for indicating a maximum allowed backoff threshold value, and the first indication frame includes a beacon frame or a management frame, where the maximum allowed backoff threshold value is used to indicate a maximum backoff number of a station;

the target field comprises the maximum allowed backoff threshold value; alternatively, the first and second electrodes may be,

the processor 1010 generates a backoff random value, which belongs to a preset range;

the processor 1010 performs backoff based on the backoff random value, and if the backoff is completed within the range allowed by the maximum allowed backoff threshold value, the station accesses the target channel.

If the station does not finish backoff within the range of the maximum allowed backoff threshold value, the processor 1010 controls the station to suspend backoff until the end time related to the uplink PPDU;

and when the end time related to the uplink PPDU is reached, the processor detects whether the target channel is idle, and if the target channel is idle, the backoff is recovered.

Optionally, the radio frequency circuit 1040 receives a second indication frame, where the second indication frame includes a first Basic Service Set Identifier (BSSID) and a feature field for indicating that the BSS Color is updated, and the feature field carries the updated BSS Color;

processor 1010 matches the first BSSID with a second BSSID for the station;

if the match is consistent, the processor 1010 updates the second BSS Color to the updated BSS Color.

before the processor 1010 measures a second received signal strength RSSI2 based on a second signal in the PPDU, the method further includes:

if the predetermined field is detected to indicate that the beam directions for transmitting the first signal and the second signal are different, the processor 1010 measures the RSSI2 based on the second signal in the PPDU.

If the station detects that the preset field indicates that the beam directions for transmitting the first signal and the second signal are the same, the processor 1010 determines whether contention access of the target channel can be performed and whether the end time for accessing the target channel can exceed the start time of transmission of a downlink PPDU adjacent to the uplink PPDU according to the RSSI 1.

It is understood that the specific implementation of the respective components in the above-described sites may further refer to the relevant description in the method embodiments.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.

The steps in the method of the embodiment of the invention can be sequentially adjusted, combined and deleted according to actual needs.

The modules in the terminal of the embodiment of the invention can be combined, divided and deleted according to actual needs.

The components such as the microcontroller according to the embodiment of the present invention may be implemented by a general-purpose Integrated Circuit, such as a CPU, or an Application Specific Integrated Circuit (ASIC).

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention, and it is therefore to be understood that the invention is not limited by the scope of the appended claims.

Claims

1. A method for accessing a channel, comprising:

if the target channel is an uplink PPDU, the station measures a first received signal strength RSSI1 based on a first signal in the PPDU, and the first signal is sent in a target frequency domain resource of the target channel;

the station measures a second received signal strength, RSSI, 2 based on a second signal in the PPDU, the frequency domain resource used by the second signal being all or part of the target frequency domain resource;

the site comparing whether the first basic service set identifier is consistent with a second basic service set identifier of the site;

if not, the station determines whether the RSSI2 is smaller than the second threshold, and whether the received signal strength of the trigger frame received by the station for triggering the uplink PPDU is smaller than a fourth threshold, so as to determine whether contention access of the target channel can be performed.

2. The method of claim 1, wherein the determining, by the station, whether the RSSI2 is less than the second threshold and whether the received signal strength of the trigger frame received by the station for triggering the uplink PPDU is less than a fourth threshold, whether contention access for the target channel is enabled comprises:

and the station judges that the RSSI2 is smaller than the second threshold value, and the received signal strength of a trigger frame which is received by the station and used for triggering the uplink PPDU is smaller than a fourth threshold value, so that the station can perform the competitive access of the target channel.

3. The method as claimed in claim 1 or 2, wherein the determining, by the station, whether the RSSI2 is less than the second threshold and whether the received signal strength of the trigger frame received by the station for triggering the uplink PPDU is less than a fourth threshold, and after determining whether contention access for the target channel is enabled, comprises:

if the station judges that the competitive access of the target channel can be carried out, the station competitively accesses the target channel;

and the station determines whether the end time of accessing the target channel can exceed the transmission start time of a downlink PPDU adjacent to the uplink PPDU according to the RSSI 1.

4. The method of claim 1, wherein the first signal comprises a legacy short training field (L-STF) and a legacy long training field (L-LTF) in the uplink PPDU;

5. The method of claim 4, wherein the station determining whether an end time of accessing the target channel can exceed a start time of a downlink PPDU transmission adjacent to the uplink PPDU based on the RSSI1 comprises:

6. The method of claim 1, wherein the station contending for access to the target channel comprises:

the station detects the signal strength of a signal carried by the target channel;

and if the signal intensity is smaller than a third threshold value, the station contends to access the target channel.

7. The method of claim 1, wherein the method further comprises:

the station receives a first indication frame, wherein the first indication frame comprises a target field used for indicating a maximum allowed backoff threshold value, the first indication frame comprises a beacon frame or a management frame, and the maximum allowed backoff threshold value is used for indicating the maximum backoff number of the station;

the station contends for access to the target channel, including:

the station generates a backoff random value, and the backoff random value belongs to a preset range;

and the station performs backoff based on the backoff random value, and if the backoff is completed within the allowed range of the maximum allowed backoff threshold value, the station accesses the target channel.

8. The method of claim 7, wherein the target field comprises the maximum allowed backoff threshold value; alternatively, the first and second electrodes may be,

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

when the end time related to the uplink PPDU is reached, the station detects whether the target channel is idle, and if the target channel is idle, the station resumes back-off;

10. The method of claim 1, wherein the basic service set identifier is a service set color, BSSColor, the method further comprising:

the station receives a second indication frame, wherein the second indication frame comprises a first Basic Service Set Identifier (BSSID) and a characteristic field used for indicating the update of a BSS Color, and the characteristic field carries the updated BSS Color;

the station matching the first BSSID to a second BSSID of the station;

and if the matching is consistent, the station updates the second BSS Color to the updated BSS Color.

11. A station, comprising:

the processor is used for detecting whether the PDU is an uplink PPDU or not;

if not, the processor is further configured to determine whether the RSSI2 is smaller than the second threshold, and whether the received signal strength of the trigger frame received by the station for triggering the uplink PPDU is smaller than a fourth threshold, so as to determine whether contention access of the target channel can be performed.

12. The station of claim 11, wherein the processor is specifically configured to determine that the RSSI2 is less than the second threshold and that a received signal strength of a trigger frame received by the station for triggering the uplink PPDU is less than a fourth threshold, and to determine that contention access for the target channel is available.

13. The station of claim 11 or 12, wherein the processor is further configured to contend for access to the target channel if contention for access to the target channel is available;

the processor is further configured to determine whether an end time of accessing the target channel can exceed a start time of transmission of a downlink PPDU adjacent to the uplink PPDU according to the RSSI 1.

14. The station of claim 11, wherein the first signal comprises a legacy short training field L-STF and a legacy long training field L-LTF in an uplink PPDU preamble;

15. The station of claim 14, wherein the processor determining whether the end time of the access target channel can exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU according to the RSSI1 specifically comprises:

the processor judges that the RSSI1 is smaller than a first threshold value, and determines that the end time of accessing a target channel can exceed the transmission start time of a downlink PPDU adjacent to the uplink PPDU;

the processor determines that the RSSI1 is greater than a first threshold, and determines that the end time of the access target channel cannot exceed the start time of the transmission of the downlink PPDU adjacent to the uplink PPDU.

16. The station of claim 12, wherein the processor contending for access to the target channel comprises:

17. The station of claim 11, wherein the radio frequency circuitry is further configured to receive a first indication frame, the first indication frame including a target field for indicating a maximum allowed backoff threshold value, the first indication frame including a beacon frame or a management frame, the maximum allowed backoff threshold value being used for indicating a maximum backoff number of the station;

and the processor performs backoff based on the backoff random value, and if the backoff is completed within the allowed range of the maximum allowed backoff threshold value, the station accesses the target channel.

18. The station of claim 17, wherein the target field comprises a maximum allowed backoff threshold value; alternatively, the first and second electrodes may be,

the target field comprises a reference value used for representing a maximum allowed backoff threshold value, the maximum allowed backoff threshold value is determined by the reference value and a value of a preset field in the uplink PPDU, and the value of the preset field is a coefficient.

19. The station of claim 18, wherein if the station does not complete backoff within the range of the maximum allowed backoff threshold value, the processor controls the station to suspend backoff until the end time associated with the uplink PPDU;

and when the end time related to the uplink PPDU is reached, the processor detects whether a target channel is idle, and if the target channel is idle, the backoff is recovered.

20. The station of claim 11, wherein the basic service set identifier is a service set Color, BSS Color;

the radio frequency circuit receives a second indication frame, wherein the second indication frame comprises a first Basic Service Set Identifier (BSSID) and a characteristic field for indicating updating of a BSS Color, and the characteristic field carries the updated BSS Color;

the processor matches the first BSSID to a second BSSID of the station;

and if the matching is consistent, the processor updates the second BSS Color to the updated BSS Color.