CN112533252B - Channel access method and station - Google Patents

Abstract

Embodiments of the present invention disclose a channel access method and a station. The channel access method includes: when a station receives a PPDU on a target channel, detecting whether the PPDU is an uplink PPDU, and if it is an uplink PPDU, based on a first signal in the PPDU Measure RSSI1; obtain the first basic service set identifier in the PPDU, the station measures RSSI2 based on the second signal in the PPDU, and compares whether the first basic service set identifier and the station's second basic service set identifier are consistent, If not, according to RSSI2, determine whether the target channel can be competed for access; if so, the station competes to access the target channel; according to RSSI1, the station determines whether the end time of accessing the target channel can exceed the transmission of the downlink PPDU adjacent to the uplink PPDU start time. By adopting the embodiments of the present invention, it can not only ensure that there is no interference to the transmission of the uplink PPDU, but also can ensure that the transmission of the downlink PPDU adjacent to the uplink PPDU does not interfere.

Description

A channel access method and site

technical field

The present invention relates to the technical field of wireless networks, and in particular, to a channel access method and a site.

Background technique

At present, there are often multiple basic service sets (Basic Service Sets, BSSs) in the current wireless local area network, wherein, each BSS includes one or more stations (Station, STA), of course, some BSSs may also include AP access points ( Access Point, AP), for example: all BSSs include APs, or only some BSSs include APs. The STA can be associated with the AP in the BSS to which the STA belongs, or can be associated with the AP in other BSSs. The STA performs network transmission through the associated AP. Each BSS has a unique basic service set identifier, which belongs to all BSSs of the BSS. Sites all have the BSS's Basic Service Set Identifier.

In practical applications, it is common for multiple BSSs working on the same channel (that is, multiple BSSs working on the same channel and with different basic service set identifiers) to overlap in the coverage area, thus forming a Overlapping BSS (Overlapping BSS, OBSS), that is, an OBSS and another or more BSSs have overlapping coverage areas on the same channel. For example, if BSS1 and BSS2 use the same channel, and the coverage areas of BSS1 and BSS2 on the same channel overlap, then BSS1 is the OBSS of BSS2, or BSS2 is the OBSS of BSS1, and the sites that are OBSS can be Use the same channel for data transmission.

As shown in Figure 1, assuming that STA1 and STA2 are OBSS sites, AP1 is the access point associated with STA2, AP1 sends a trigger frame, and STA2 sends an uplink physical layer protocol data unit (physical layer (PHY) protocol data unit, PPDU). STA1 that uses the same target channel and is an OBSS station with STA2 can receive the uplink PPDU. STA1 will measure the signal strength of the PPDU. When the measured signal strength is higher than the maximum spatial multiplexing threshold, it determines that the target channel is prohibited from spatial reuse. When the measured signal strength is lower than the maximum spatial multiplexing threshold, it is determined. The above target channel is to allow space reuse, and access the target channel.

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 an acknowledgment frame sent by the AP.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a channel access method and a site, which can not only ensure no interference to uplink PPDU transmission, but also ensure no interference to downlink PPDU transmission adjacent to the uplink PPDU.

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

When the station receives the physical layer protocol data unit PPDU on the target channel, it detects whether the PPDU is an uplink PPDU;

If it is an uplink PPDU, the station measures the first received signal strength (Received Signal Strength Indication, RSSI1) based on the first signal in the PPDU, and the first signal is sent in the target frequency domain resource of the target channel;

The station obtains the first basic service set identifier in the PPDU preamble signal;

The station measures the second received signal strength RSSI2 based on the second signal in the PPDU, and the frequency domain resources used by the second signal are all or part of the target frequency domain resources;

The site compares whether the first basic service set identifier is consistent with the site's own second basic service set identifier;

If it is inconsistent, the site determines whether the contention access of the target channel can be performed according to RSSI2;

If so, the station competes for access to the target channel;

The station determines 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 according to RSSI1. In this way, the station determines through RSSI2 whether it can compete to access the target channel. If so, it competes to access the target channel for spatial reuse. Further, the station determines whether the end time of accessing the target channel is through RSSI1. It can exceed the start time of downlink PPDU transmission adjacent to the uplink PPDU, that is, to determine whether it will interfere with the station's reception of downlink PPDUs. In this way, in the process of spatial reuse, it not only ensures that there is no interference to uplink PPDU transmission, but also ensures that there is no downlink PPDU transmission. The interference of PPDU transmission can also reduce the listening time of the site and save the energy of the site.

Optionally, according to RSSI2, the above-mentioned site determines whether contention access to the target channel can be performed specifically including:

If RSSI2 is less than the second threshold, and the station has not received the trigger frame for triggering the sending of the uplink PPDU, the station determines that the contention access of the target channel can be performed;

If RSSI2 is less than the second threshold, and the received signal strength of the trigger frame received by the station for triggering the sending of the uplink PPDU is less than the fourth threshold, the station determines that contention access to the target channel can be performed. In this way, whether the station will cause interference to the uplink PPDU transmission is determined by the received signal strength of the trigger frame.

Based on the first aspect, in a first feasible implementation manner of the first aspect, the above-mentioned first signal includes the legacy short training field (Legacy Short Training Field, L-STF) and the traditional long training training in the upstream PPDU preamble signal Field (Legacy Long Training Field, L-LTF);

The above-mentioned second signal includes a High Efficient Short Training Field (HE-STF), a High Efficient Long Training Field (HE-LTF), and a High Efficient Data Field (High Efficient Data) in the uplink PPDU. HE-DATA) at least one.

Based on the first aspect, in a second feasible implementation manner of the first aspect, the above-mentioned downlink PPDU includes an acknowledgement frame (Acknowledgement, ACK) or a multi-user block acknowledgment (Multi-block acknowledgment, MU-BA) for the uplink PPDU.

Based on the first aspect or the first feasible implementation manner of the first aspect or the second feasible implementation manner of the first aspect, in the third feasible implementation manner of the first aspect, the site determines whether the target can be performed according to RSSI2 Contention access to channels, including:

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

If RSSI2 is less than the second threshold, the station determines that contention access to the target channel can be performed, that is, spatial reuse can be performed. In this manner, by comparing RSSI2 with the second threshold, it can be determined whether the uplink PPDU transmission will cause interference to the station sending and receiving data, so as to determine whether to perform space sharing within the uplink PPDU transmission time.

Based on the third feasible implementation manner of the first aspect, in the fourth feasible implementation manner of the first aspect, the station determines whether the end time of accessing the target channel can exceed the transmission of the downlink PPDU adjacent to the uplink PPDU according to RSSI1 start time, including:

If 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 downlink PPDU transmission adjacent to the uplink PPDU;

If 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 transmission of the downlink PPDU adjacent to the uplink PPDU. In this way, by comparing RSSI1 with the first threshold, the interference strength between the station and the station sending the uplink PPDU can be determined, and it can be further determined whether the station sending and receiving data will cause the station sending the uplink PPDU to receive the downlink PPDU. interference.

Based on the first aspect, in a fifth feasible implementation manner of the first aspect, the stations compete for access to the target channel, including:

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

If the signal strength is less than the third threshold, the station competes to access the target channel. Since all stations that are OBSS stations with the station sending the uplink PPDU are competing to access the target channel for spatial reuse, in order to ensure the transmission quality of the signal carried by the target channel, the signal strength of the bearer signal cannot be too large, and the station is in the target channel. When competing for access to the target channel, by detecting the signal strength of the signal carried by the target channel, it is determined whether to compete for access, so as to ensure the transmission quality of the signal carried by the target channel.

Optionally, if the signal strength is greater than the third threshold, the station suspends back-off until the end of the uplink PPDU transmission or suspends the back-off until a time determined by a preset offset after the end of the uplink PPDU transmission.

Based on the first aspect, in a sixth feasible implementation manner of the first aspect, the method further includes:

The station receives a first indication frame, the first indication frame contains a target field used to indicate the maximum allowable backoff threshold, the first indication frame includes a beacon frame or a management frame, and the maximum allowable backoff threshold is used to indicate the station The maximum number of backoffs;

Stations contend for access to the target channel, including:

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

The station backs off based on the backoff random value. If the backoff is completed within the allowable range of the maximum allowable backoff threshold, the station accesses the target channel. By indicating the maximum allowable backoff threshold value, the number of stations competing to access the target channel for space sharing is guaranteed, thereby ensuring the transmission quality of the target channel transmission signal.

Based on a sixth feasible implementation manner of the first aspect, in a seventh feasible implementation manner of the first aspect, the target field includes a maximum allowable backoff threshold value; or,

The target field includes a reference value for representing the maximum allowable backoff threshold, and the maximum allowable backoff threshold is determined by the reference value and the value of a preset field in the uplink PPDU, and the value of the preset field may be a coefficient . The number of sites for space reuse is limited by various indications of the maximum allowable backoff threshold.

Based on the seventh feasible implementation manner of the first aspect, in the eighth feasible implementation manner of the first aspect, the method further includes:

If the station does not complete the back-off within the allowable range of the maximum allowable back-off threshold, the station suspends back-off until the end time related to the uplink PPDU;

When reaching the end time related to the uplink PPDU, the station detects whether the target channel is idle, and if it is idle, it resumes backoff.

The end time related to the uplink PPDU includes the end of signal transmission of the uplink PPDU, or the end of transmission of the acknowledgment frame corresponding to the uplink PPDU, or an offset time added after the end of signal transmission of the uplink PPDU. It is further limited that the station does not complete the back-off within the allowable range of the maximum allowable back-off threshold value, then the back-off is suspended until the end of the PPDU transmission, and the number of stations performing space sharing in the target channel is controlled.

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:

The station receives a second indication frame, and the second indication frame includes the first basic service set identifier (Basic ServiceSet Identifier, BSSID) and a feature field for indicating that the BSS Color is updated, and the feature field carries the updated BSS Color;

The site matches the first BSSID with the second BSSID of the site;

If the matches are consistent, the site updates the second BSS Color to the above-mentioned updated BSS Color. This embodiment provides an update method of BSS Color, which facilitates the expansion of the local area network, and the site can still update the BSS Color according to the BSSID.

Optionally, the above-mentioned uplink PPDU may further include a preset field, where the preset field is used to indicate that the beam direction of the above-mentioned first signal and the above-mentioned second signal are changed;

Before the above-mentioned station measures the second received signal strength RSSI2 based on the 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 RSSI2 based on the second signal in the PPDU.

If the station detects that the preset field indicates that the beam directions for sending the first signal and the second signal are the same, according to the RSSI1, determine whether the contention access to the target channel can be performed and whether the end time of accessing the target channel can exceed the uplink The start time of downlink PPDU transmission adjacent to the PPDU. In this way, a preset field is used to indicate the change of the beam direction, so as to determine whether to measure RSSI2 through this field, which can reduce the measurement time of the station.

A second aspect of the present invention provides a site, which may include:

a receiving module for receiving the physical layer protocol data unit PPDU on the target channel;

a processing module for detecting whether the PPDU is an uplink PPDU;

The processing module is further configured to measure the first received signal strength (Received Signal Strength Indication, RSSI1) based on the first signal in the PPDU if it is an uplink PPDU, and the first signal is sent in the target frequency domain resource of the target channel;

The processing module is further configured to obtain the first basic service set identifier in the PPDU preamble signal;

The processing module is further configured to measure the second received signal strength RSSI2 based on the 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;

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

If inconsistent, the processing module is further configured to determine whether the contention access of the target channel can be performed according to RSSI2;

a channel access module, configured to compete for access to the target channel if the target channel can be competed for access;

The processing module is further configured to determine, 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. In this way, the station determines through RSSI2 whether it can compete to access the target channel. If so, it competes to access the target channel for spatial reuse. Further, the station determines whether the end time of accessing the target channel is through RSSI1. It can exceed the start time of downlink PPDU transmission adjacent to the uplink PPDU, that is, to determine whether it will interfere with the station's reception of downlink PPDUs. In this way, in the process of spatial reuse, it not only ensures that there is no interference to uplink PPDU transmission, but also ensures that there is no downlink PPDU transmission. The interference of PPDU transmission can also reduce the listening time of the site and save the energy of the site.

Optionally, according to RSSI2, the above-mentioned site determines whether contention access to the target channel can be performed specifically including:

If RSSI2 is less than the second threshold, and the station has not received the trigger frame for triggering the sending of the uplink PPDU, the station determines that the contention access of the target channel can be performed;

If RSSI2 is less than the second threshold, and the received signal strength of the trigger frame received by the station for triggering the sending of the uplink PPDU is less than the fourth threshold, the station determines that contention access to the target channel can be performed. In this way, whether the station will cause interference to the uplink PPDU transmission is determined by the received signal strength of the trigger frame.

Based on the second aspect, in a first feasible implementation manner of the second aspect, the above-mentioned first signal includes a legacy short training field (Legacy Short Training Field, L-STF) and a traditional long training field in the upstream PPDU preamble signal Field (Legacy Long Training Field, L-LTF);

The above-mentioned second signal includes a High Efficient Short Training Field (HE-STF), a High Efficient Long Training Field (HE-LTF), and a High Efficient Data Field (High Efficient Data) in the uplink PPDU. HE-DATA) at least one.

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

Based on the second aspect or the first feasible implementation manner of the second aspect or the second feasible implementation manner of the second aspect, in a third feasible implementation manner of the second aspect, the processing module, according to the RSSI2, Determining whether contention access to the target channel can be performed specifically includes:

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

If the RSSI2 is less than the second threshold, the processing module determines that contention access to the target channel can be performed. In this manner, by comparing RSSI2 with the second threshold, it can be determined whether the uplink PPDU transmission will cause interference to the station sending and receiving data, so as to determine whether to perform space sharing within the uplink PPDU transmission time.

Based on the third feasible implementation manner of the second aspect, in a fourth feasible implementation manner of the second aspect, the processing module determines, according to the RSSI1, whether the end time of accessing the target channel can exceed the The start time of the transmission of the downstream PPDU adjacent to the upstream PPDU specifically includes:

If the RSSI1 is less than the first threshold, the processing module determines that the end time of accessing the target channel can exceed the start time of downlink PPDU transmission 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 transmission of the downlink PPDU adjacent to the uplink PPDU. In this way, by comparing RSSI1 with the first threshold, the interference strength between the station and the station sending the uplink PPDU can be determined, and it can be further determined whether the station sending and receiving data will cause the station sending the uplink PPDU to receive the downlink PPDU. interference.

Based on the second aspect, in a fifth feasible implementation manner of the second aspect, the channel access module competing for access to the target channel specifically includes:

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

If the signal strength is less than a third threshold, the channel access module competes for access to the target channel. Since all stations that are OBSS stations with the station sending the uplink PPDU are competing to access the target channel for spatial reuse, in order to ensure the transmission quality of the signal carried by the target channel, the signal strength of the bearer signal cannot be too large, and the station is in the target channel. When competing for access to the target channel, by detecting the signal strength of the signal carried by the target channel, it is determined whether to compete for access, so as to ensure the transmission quality of the signal carried by the target channel.

Optionally, if the signal strength is greater than the third threshold, the station suspends back-off until the end of the uplink PPDU transmission or suspends the back-off until a time determined by a preset offset after the end of the uplink PPDU transmission.

Based on the second aspect, in a sixth feasible implementation manner of the second aspect, the receiving module is further configured to receive a first indication frame, where the first indication frame includes a value used to indicate a maximum allowable backoff threshold Target field, the first indication frame includes a beacon frame or a management frame, and the maximum allowable backoff threshold is used to indicate the maximum backoff times of the station;

The channel access module competing for access to the target channel specifically includes:

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

The channel access module performs backoff based on the backoff random value, and if backoff is completed within the allowable range of the maximum allowable backoff threshold, the station accesses the target channel. By indicating the maximum allowable backoff threshold value, the number of stations competing to access the target channel for space sharing is guaranteed, thereby ensuring the transmission quality of the target channel transmission signal.

Based on a sixth feasible implementation manner of the second aspect, in a seventh feasible implementation manner of the second aspect, the target field includes a maximum allowable backoff threshold value; or,

The target field includes a reference value for representing the maximum allowable backoff threshold, and the maximum allowable backoff threshold is determined by the reference value and the value of a preset field in the uplink PPDU, and the value of the preset field may be a coefficient . The number of sites for space reuse is limited by various indications of the maximum allowable backoff threshold.

Based on a seventh feasible implementation manner of the second aspect, in an eighth feasible implementation manner of the second aspect, the channel access module is further configured to: If the station has not completed the backoff, the backoff is suspended until the end time related to the uplink PPDU;

When reaching the end time related to the uplink PPDU, the channel access module detects whether the target channel is idle, and if it is idle, resumes backoff. It is further limited that the station does not complete the back-off within the allowable range of the maximum allowable back-off threshold value, then the back-off is suspended until the end of the PPDU transmission, and the number of stations performing space sharing in the target channel is controlled.

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, the second indication frame Including the first basic service set identification BSSID and the characteristic field for indicating that the BSS Color is updated, and the characteristic field carries the updated BSSColor;

The processing module is further configured to match the first BSSID with the second BSSID of the site;

The processing module is further configured to update the second BSS Color to the updated BSS Color if the matches are consistent. This embodiment provides an update method of BSS Color, which facilitates the expansion of the local area network, and the site can still update the BSS Color according to the BSSID.

Optionally, the above-mentioned uplink PPDU may further include a preset field, where the preset field is used to indicate that the beam direction of the above-mentioned first signal and the above-mentioned second signal are changed;

Before measuring the second received signal strength RSSI2 based on the 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 RSSI2 based on the second signal in the PPDU.

If the processing module detects that the preset field indicates that the beam directions for sending the first signal and the second signal are the same, then according to the RSSI1, it is determined whether contention access to the target channel can be performed and whether the end time of accessing the target channel can exceed The start time of the transmission of the downstream PPDU adjacent to the upstream PPDU. In this way, a preset field is used to indicate the change of the beam direction, so as to determine whether to measure RSSI2 through this field, which can reduce the measurement time of the site.

A third aspect of the present invention provides a site, comprising:

a radio frequency circuit for receiving the physical layer protocol data unit PPDU on the target channel;

a processor for detecting whether the PDU is an uplink PPDU;

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

The processor is further configured to acquire the first basic service set identifier in the PPDU preamble signal;

The processor is further configured to measure the second received signal strength RSSI2 based on the 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;

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

If inconsistent, the processor is further configured to determine, according to the RSSI2, whether contention access to the target channel can be performed;

The processor is further configured to compete for access to the target channel if the target channel can be competed for access;

The processor is further configured to determine, 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. In this way, the station determines through RSSI2 whether it can compete to access the target channel. If so, it competes to access the target channel for spatial reuse. Further, the station determines whether the end time of accessing the target channel is through RSSI1. It can exceed the start time of downlink PPDU transmission adjacent to the uplink PPDU, that is, to determine whether it will interfere with the station's reception of downlink PPDUs. In this way, in the process of spatial reuse, it not only ensures that there is no interference to uplink PPDU transmission, but also ensures that there is no downlink PPDU transmission. The interference of PPDU transmission can also reduce the listening time of the site and save the energy of the site.

Optionally, the above-mentioned processor determines, according to RSSI2, whether contention access to the target channel can be performed, specifically:

If RSSI2 is less than the second threshold, and the station does not receive a trigger frame for triggering the sending of the uplink PPDU, it is determined that contention access to the target channel can be performed;

If RSSI2 is less than the second threshold, and the received signal strength of the trigger frame received by the station for triggering the sending of the uplink PPDU is less than the fourth threshold, it is determined that contention access to the target channel can be performed. In this way, whether the station will cause interference to the uplink PPDU transmission is determined by the received signal strength of the trigger frame.

Based on the third aspect, in a first feasible implementation manner of the third aspect, the above-mentioned first signal includes the traditional short training field L-STF and the traditional long training field L-LTF in the upstream PPDU preamble signal;

The above-mentioned second signal includes at least one of the high-efficiency short-training training field HE-STF, the high-efficiency long-training training field HE-LTF and the high-efficiency data field HE-DATA in the uplink PPDU.

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

Based on the third aspect or the first feasible implementation manner of the third aspect or the second feasible implementation manner of the third aspect, in the third feasible implementation manner of the third aspect, the processor determines, according to RSSI2, whether to perform The contention access of the target channel specifically includes:

If RSSI2 is greater than the second threshold, the processor determines that the contention access of the target channel cannot be performed; that is, spatial reuse cannot be performed;

If RSSI2 is less than the second threshold, the processor determines that contention access to the target channel can be performed, that is, spatial reuse can be performed. In this manner, by comparing RSSI2 with the second threshold, it can be determined whether the uplink PPDU transmission will cause interference to the station sending and receiving data, so as to determine whether to perform space sharing within the uplink PPDU transmission time.

Based on the third feasible implementation manner of the third aspect, in the fourth feasible implementation manner of the third aspect, the processor determines whether the end time of accessing the target channel can exceed the downlink PPDU adjacent to the uplink PPDU according to RSSI1 The start time of the transfer specifically includes:

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

If 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 transmission of the downlink PPDU adjacent to the uplink PPDU. In this way, by comparing RSSI1 with the first threshold, the interference strength between the station and the station sending the uplink PPDU can be determined, and it can be further determined whether the station sending and receiving data will cause the station sending the uplink PPDU to receive the downlink PPDU. interference.

Based on the third aspect, in a fifth feasible implementation manner of the third aspect, the processor competing for access to the target channel specifically includes:

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

If the signal strength is less than the third threshold, the processor competes for access to the target channel. Since all stations that are OBSS stations with the station sending the uplink PPDU are competing to access the target channel for spatial reuse, in order to ensure the transmission quality of the signal carried by the target channel, the signal strength of the bearer signal cannot be too large, and the station is in the target channel. When competing for access to the target channel, by detecting the signal strength of the signal carried by the target channel, it is determined whether to compete for access, so as to ensure the transmission quality of the signal carried by the target channel.

Optionally, if the signal strength is greater than the third threshold, the station suspends back-off until the end of the uplink PPDU transmission or suspends the back-off until a time determined by a preset offset after the end of the uplink PPDU transmission.

Based on the third aspect, in a sixth feasible implementation manner of 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 used to indicate a maximum allowable backoff threshold value, the first indication frame includes a beacon frame or a management frame, and the maximum allowable backoff threshold value Used to indicate the maximum number of backoffs for the site;

The processor competing for access to the target channel specifically includes:

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

The processor performs backoff based on the backoff random value. If backoff is completed within the allowable range of the maximum allowable backoff threshold value, the station accesses the target channel. By indicating the maximum allowable backoff threshold value, the number of stations competing to access the target channel for space sharing is guaranteed, thereby ensuring the transmission quality of the target channel transmission signal.

Based on a sixth feasible implementation manner of the third aspect, in a seventh feasible implementation manner of the third aspect, the target field includes a maximum allowable backoff threshold value; or,

The target field includes a reference value for representing the maximum allowable backoff threshold, and the maximum allowable backoff threshold is determined by the reference value and the value of a preset field in the uplink PPDU, and the value of the preset field may be a coefficient . The number of sites for space reuse is limited by various indications of the maximum allowable backoff threshold.

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

When reaching the end time related to the uplink PPDU, the processor detects whether the target channel is idle, and if it is idle, it resumes backoff. It is further limited that the station does not complete the back-off within the allowable range of the maximum allowable back-off threshold value, then the back-off is suspended until the end of the PPDU transmission, and the number of stations performing space sharing in the target channel is controlled.

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 instruction frame, and the second instruction frame includes a first basic service set identifier (BasicService Set Identifier, BSSID) and a feature field for indicating that the BSS Color is updated, and the feature field carries the updated BSS Color;

The processor matches the first BSSID with the second BSSID of the site;

If the matches are consistent, the processor updates the second BSS Color to the above-mentioned updated BSS Color. This embodiment provides an update method of BSS Color, which facilitates the expansion of the local area network, and the site can still update the BSS Color according to the BSSID.

Optionally, the above-mentioned uplink PPDU may further include a preset field, where the preset field is used to indicate that the beam direction of the above-mentioned first signal and the above-mentioned second signal are changed;

Before measuring the second received signal strength RSSI2 based on the second signal in the PPDU, the above-mentioned processor further includes:

If it is detected that the preset field indicates that the beam directions for transmitting the first signal and the second signal are different, the processor measures RSSI2 based on the second signal in the PPDU.

If the station detects that the preset field indicates that the beam directions for sending the first signal and the second signal are the same, according to the RSSI1, determine whether the contention access to the target channel can be performed and whether the end time of accessing the target channel can exceed the uplink The start time of downlink PPDU transmission adjacent to the PPDU. In this way, a preset field is used to indicate the change of the beam direction, so as to determine whether to measure RSSI2 through this field, which can reduce the measurement time of the station.

In this embodiment of the present invention, when a station receives a PPDU on a target channel, it detects whether the PPDU is an uplink PPDU, and if it is an uplink PPDU, it measures RSSI1 based on the first signal, and further acquires the first basic service set identifier in the PPDU preamble signal. , measure RSSI2 based on the second signal, compare whether the first basic service set identifier is consistent with the second basic service set identifier of the site, if not, determine whether the contention access of the target channel can be performed according to RSSI2, if so, the competition Access the target channel, and further determine whether the end time of the access target channel can exceed the start time of downlink PPDU transmission according to RSSI1, which not only ensures no interference to uplink PPDU transmission, but also ensures no interference to downlink PPDU transmission.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic diagram of an application scenario provided by an embodiment of the present invention;

2 is a schematic flowchart of a channel access method provided by an embodiment of the present invention;

3 is a schematic structural diagram of an uplink PPDU provided by an embodiment of the present invention;

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

FIG. 5 is a diagram of another channel access scenario provided by an embodiment of the present invention;

FIG. 6 is a diagram of another channel access scenario provided by an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a site provided by an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of another site provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The service set color BSS Color in the embodiment of the present invention is an identifier with fewer bits (for example, only 3 bits or 4 bits), and is used to distinguish adjacent BSSs.

The basic service set identifier BSSID in the embodiment of the present invention is an identifier with a large number of bits (usually 46 bits), and is used to distinguish adjacent BSSs.

The BSSID usually does not change, while the BSS Color can be updated.

The embodiments of the present invention may be applied to a wireless local area network (Wireless Local Area Network, WLAN). Currently, the standard adopted by the WLAN is the IEEE (English: Institute of Electrical and Electronics Engineers, Chinese: Institute of Electrical and Electronics Engineers) 802.11 series. A WLAN may include multiple basic service sets (BSS), the network nodes in the basic service set are stations, and the stations include an access point type station AP and a non-access point type station (English: None Access Point Station, referred to as: Non-AP STA). ), each basic service set may contain one AP and multiple Non-AP STAs associated with the AP.

Access point type sites, also known as wireless access points or hotspots, etc. APs are access points for mobile users to access wired networks. They are mainly deployed in homes, buildings, and campuses, with a typical coverage radius ranging from tens of meters to hundreds of meters. Of course, they can also be deployed outdoors. AP is equivalent to a bridge connecting wired network and wireless network. Its main function is to connect various wireless network clients together, and then connect the wireless network to Ethernet. Specifically, the AP may be a terminal device or a network device with a WiFi (English: Wireless Fidelity, Chinese: Wireless Fidelity) chip. Optionally, the AP may be a device supporting the 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 802.11a.

A non-access point station (English: None Access Point Station, referred to as: Non-AP STA) can be a wireless communication chip, a wireless sensor or a wireless communication terminal. For example: mobile phones that support WiFi communication, tablet computers that support WiFi communication, set-top boxes that support WiFi communication, smart TVs that support WiFi communication, smart wearable devices that support WiFi communication, in-vehicle communication that supports WiFi communication Devices and computers that support WiFi communication. Optionally, the station STA may support the 802.11ax standard, and further optionally, the station supports multiple WLAN standards such as 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a.

Please refer to FIG. 1, which is a system schematic diagram of a typical WLAN deployment scenario, including one AP and 4 STAs. AP1, STA2, STA3, and STA4 belong to a BSS (STA2, STA3, and STA4 are associated with AP1), and STA1 belongs to the same BSS. Another BSS, each BSS has a basic service set identifier, which is used to identify the BSS and distinguish it from adjacent BSSs.

Assume that the BSS to which AP1, STA2, STA3, and STA4 belong is BSS1, and the BSS to which STA1 belongs is BSS2. BSS1 and BSS2 are each other's OBSS, and the stations that are each other's OBSS can use the same channel for data transmission. In order to solve the problem of making full use of channel resources , the concept of space reuse is proposed and studied. Space reuse is that the stations that are OBSSs of each other transmit data on the same channel at the same time.

In order to ensure the communication quality, in the process of spatial reuse, the data transmission of the stations (such as STA1 in FIG. 1 ) that are competing for the access channel subsequently cannot send uplink PPDUs to the communicating stations (such as the station STA2 in FIG. 1 ) to AP1 ) causes interference, and STA1 also needs to ensure that its own data transmission will not be interfered by the uplink PPDU being transmitted by STA2.

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

The station STA1 listens to the channel and finds that the interference/noise energy exceeds a predetermined threshold, for example, when the interference/noise energy exceeds -62dBm, the channel is judged to be busy;

Or the station STA1 receives a physical layer preamble (PHY Preamble), the preamble carries the BSS identifier BSSColor, and the BSS Color is the same as the BSS Color identifier of the station, and the packet is considered to be a BSS packet. Since the AP in this cell is communicating with other stations but cannot communicate with the station, the station marks the channel as busy within the duration carried by the preamble. During this time the station can sleep to save energy;

Or the station STA1 receives a physical layer preamble (PHY Preamble), 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, in order to protect the communication of the OBSS, the local station marks the channel as busy within the duration carried by the preamble.

Or the station STA1 receives a physical layer preamble (PHY Preamble), the preamble carries the BSS Color of the BSS, and the BSS Color is different from the BSS Color of the BSS, and 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 station can ignore the packet if the transmission has no effect on the OBSS communication.

It can be seen from the above that, in the process of STA1 determining whether to perform spatial reuse according to the received data packets, it can only be ensured that STA1 does not interfere with the uplink transmission of STA2 to AP1. However, the reception of STA2 cannot be protected. Usually, after STA2 sends an uplink PPDU to AP1, AP1 needs to return an acknowledgment frame to STA2 to confirm whether the reception is complete and correct. When STA2 receives the acknowledgment frame sent by AP1, it determines the data transmission. Correct, no retransmission required.

The embodiment of the present invention provides a channel access method. When STA1 receives an uplink PPDU sent by STA2 to AP1, it can measure RSSI1 according to the first signal in the uplink PPDU, and measure RSSI2 according to the second signal in the uplink PPDU. Wherein, the first signal occupies the target frequency domain resource of the target channel, and the second signal occupies part or all of the target frequency domain resource, for example, may be one of the subbands.

STA1 determines whether the channel can be competed for access according to RSSI2, that is, to determine whether spatial reuse is possible. If spatial reuse is possible, it competes to access the channel. STA1 determines whether the end time of accessing the channel can exceed the time limit according to RSSI1. Transmission start time (eg, ACK) of the downstream PPDU adjacent to the upstream PPDU. Adopting this method of the present invention can not only ensure that the transmission of the uplink PPDU is not disturbed, but also can ensure that the downlink PPDU is not disturbed.

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

Please refer to FIG. 2 , which is a schematic flowchart of a channel access method provided by an embodiment of the present invention; as shown in FIG. 2 , the channel access method includes:

S200, when the station receives the physical layer protocol data unit PPDU on the target channel, detect whether the PPDU is an uplink PPDU;

In this embodiment of the present invention, the site is an access site AP or a non-access site. As shown in FIG. 1 , the site is a non-access site STA1, and STA1 and STA2 are each other’s OBSS sites; as shown in FIG. 4 , The station is the access type station AP1, and the AP1 and STA2 are also OBSS stations for each other.

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

As shown in FIG. 3, it is a schematic structural diagram of a PPDU provided by 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), wherein The preamble part includes the basic service set identifier (eg, BSS Color) of the station sending the uplink PPDU, and the duration Duration of the preamble.

It should be noted that, as shown in FIG. 3 , the preamble includes a traditional preamble (L-Preamble) and a high-efficiency preamble part, and the high-efficiency preamble part includes a high-efficiency signaling A (High Efficient signaling A, HE-SIGA for short) part, high-efficiency signaling Let B (High Efficient signaling B, HE-SIGB for short) part, high-efficiency short training field HE-STF and high-efficiency long training field HE-LTF, where HE-STF and HE-LTF are sent in sub-channel resources, and the preamble Other fields in the preamble are sent using non-subchannel resources (such as full-band resources), that is, other fields in the preamble are sent using the target frequency domain resources of the target channel, while the HE-STF, HE-LTF and data parts use the target frequency. Part of the channel resources of the domain resources.

As shown in FIG. 4 , taking the site as an access site as an example, AP1 and STA2 are OBSS sites for each other, AP2, STA2, STA3 and STA4 belong to one BSS, and AP1 belongs to another BSS. AP2 sends a trigger frame. Further, AP2 is based on the number of HE-LTF symbols contained in the trigger frame, the stream configuration of spatial multiplexing, the Modulation and Coding Scheme (MCS), and the cyclic prefix (Cyclic Prefix, CP) length, Transmission time, RU information (a set of subcarriers used in the frequency domain), whether to use space-time block coding (STBC) and other basic transmission parameter indication information to generate a trigger frame-based reception RXVECTOR (reception vector).

After STA2 receives the trigger frame, STA2 sends the uplink PPDU according to the indication information in the trigger frame. It should be noted that the process for AP2 to receive the uplink PPDU is as follows:

After AP2 sends the trigger frame, it sets the uplink receiving timer. Before the uplink reception 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 RSSI1. At the same time, the physical layer PHY reports this activity to a media access control layer (Media Access Control, MAC) through the PHY-CCA.indication primitive.

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

In the embodiment of the present invention, an implementation method for determining that the uplink is triggered to transmit a PPDU is that the Length modulo 3 in the L-SIG in the preamble of the PPDU is followed by 1, and the DL/UL bit in the HE-SIG is set to It is UL, and the triggered bit (or format bit, which is used to distinguish the triggered uplink transmission from other transmissions) is set to be triggered at the same time, which is "HE Trigger-based UL PPDU".

The BSS color in the preamble of the upstream PPDU is consistent with the BSS color of AP2, and AP2 will receive the upstream PPDU through the trigger-based receive vector RXVECTOR information. Specifically, channel estimation can be performed according to the HE-STF in the received uplink PPDU, including fine synchronization and automatic gain control (Automatic Gain Control, AGC) adjustment.

In this embodiment of the present invention, AP2 acquires the number of HE-LTF symbols, and the specific acquisition methods may include the following four implementation manners. Implementation 1: AP2 may acquire the HE-LTF symbols in the uplink PPDU according to the number of HE-LTF symbols in the trigger-based reception RXVECTOR - Number of LTF symbols. In implementation 2, AP2 can also obtain the number of HE-LTF symbols in the uplink PPDU according to the number of spatial streams in the trigger-based receiving RXVECTOR. In implementation 3, AP2 can also obtain the number of HE-LTF symbols in the uplink PPDU according to the number of spatial streams carried in the HE-SIG-A in the trigger-based reception RXVECTOR. In implementation 4, 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 receiving RXVECTOR. It should be noted that the subsequent information (including the CP length of the HE-LTF and the symbol length of the HE-LTF) can also be obtained by one of the above four methods.

Further, 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 method may refer to one of the above four methods. The AP may 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 in the same spatial mode (precoding or beamforming), optionally, the AP can obtain the HE-Data signal strength according to the signal strength of HE-LTF, that is, the HE-Data signal The strength is also RSSI2. It should be noted that AP2 can also measure HE-Data to obtain the signal strength of HE-Data.

After AP2 receives the uplink PPDU, AP2 will send an acknowledgment frame at an interval of a short inter-frame space (SIFS) time after the end time of the uplink PPDU or a predetermined end time.

It should be noted that, the BSS color carried in the above-mentioned PPDU refers to the BSS Color of the AP associated with the STA sending the uplink PPDU or the BSS Color of the destination AP for uplink transmission of the STA.

As shown in FIG. 4 , the station AP1 (that is, the station of the present invention) that sends the uplink PPDU as OBSS receives the PPDU signal on the target channel, and responds to the L-SIG, R-L-SIG, HE-SIG-SIG in the preamble signal. A and HE-SIG-B are decoded and verified. If the verification is correct, it is necessary to further detect whether the PPDU is an uplink PPDU and is triggered for transmission. An implementation manner of detecting and judging the uplink and being triggered to transmit the PPDU is that the Length modulo 3 in the L-SIG in the preamble of the PPDU is followed by 1, and the DL/UL bit in the HE-SIG is set to UL, and at the same time it is set to UL. If the trigger bit (or format bit, used to distinguish the triggered uplink transmission from other transmissions) is set to be triggered, the PPDU is an uplink triggered PPDU.

S201, if it 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 sent on the target frequency domain resource of the target channel, for example, the entire band of the target channel. Here, the target frequency domain resource of the target channel is an example of a 20MHZ bandwidth, and the 20MHZ bandwidth has four sub-channels. , the first signal occupies the four sub-channels, such as the preamble signals L-STF and L-LTF in the PPDU. Stations occupying each of the four subchannels can receive the first signal.

4 as an example, after AP1 receives the physical layer PHY preamble of the uplink PPDU, the physical layer PHY of the STA will measure the first received signal strength RSSI1 based on the first signal in the PPDU preamble signal. At the same time, the physical layer PHY of AP1 reports this activity to the MAC through the PHY-CCA.indication primitive.

Optionally, the first signal is sent in the target frequency domain resource of the target channel, and further optionally, the first signal may be L-STF, L-LTF, L-STF in the upstream PPDU preamble signal, and L-LTF adopts is the full-band transmission of the target channel. As shown in FIG. 3 , which is a schematic structural diagram of an uplink PPDU provided by an embodiment of the present invention, the L-STF and L-LTF in the preamble of the PPDU are all-band resource transmission. It should be noted that RSSI1 can indicate the full-band interference between AP1 and STA2.

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

In this embodiment of the present invention, the basic service set identifier may be BSSID, or the basic service set color BSSColor, or other cell identifiers, etc., which are not limited here, and the basic service set identifier is used to distinguish adjacent BSSs.

The station parses the first basic service set identifier (for example, BSS Color) carried in the PPDU preamble signal, usually the first basic service set identifier is in the HE-SIG field, and further optionally, the first basic service set identifier Matching with the second basic service set identifier of the site 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 site itself can also be placed in a subsequent channel connection. before entering.

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

In this embodiment of the present invention, the station measures the second received signal strength RSSI2 based on the second signal in the uplink PPDU, and the frequency domain resources used by the second signal are all or part of the target frequency domain used by the first signal, which may be 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 provided by an embodiment of the present invention, HE-STF, HE-LTF, and HE-DATA use sub-channel frequency domain resource transmission, while L-STF, L- The LTF adopts the full-band resource transmission of the target channel, and the bandwidth resources used by HE-STF, HE-LTF, and HE-DATA are part of the bandwidth resources used by L-STF and L-LTF. Here, the target frequency domain resource of the target channel is 20MHz bandwidth as an example for illustration. Optionally, the second signal may be a frequency domain resource occupying only one of the subchannels.

As shown in FIG. 4 , 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 sent by STA2.

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

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

Subsequent AP1 may calculate RSSI2 based on the received RXVECTOR. For a specific calculation method, please refer to the method for AP2 to calculate RSSI2 in step S200, which will not be repeated here.

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

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

The present invention does not limit the calculation method of RSSI2, and RSSI2 may indicate the interference caused by the STA2 to the AP1 when the STA2 transmits data in the uplink on a certain sub-channel of the target channel.

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

In this embodiment of the present invention, the station compares whether the first basic service set identifier parsed from the uplink PPDU is consistent with the second basic service set identifier of the station (that is, the BSS identifier associated with the station). The station detects that the first basic service set identifier in the preamble of the uplink PPDU does not match the second basic service set identifier of the station, indicating that the uplink PPDU is an uplink data packet sent by the OBSS station. If the holder of the Transmission Opportunity (TXOP) of the BSS to which the station belongs sets the Network Allocation Vector (NAV) or the station has not been set by the TXOP holder of the OBSS to set the NAV, the station can further determine whether the space reuse to compete for access to the target channel.

S205, if they are inconsistent, the station determines, according to the RSSI2, whether contention access to the target channel can be performed;

In this embodiment of the present invention, if the first basic service set identifier does not match the second basic service set identifier, the station determines whether the target channel can be competed for access according to RSSI2, that is, to determine whether the space reuse can be performed. It should be noted that, as shown in FIG. 4 , the start time of space reuse is the transmission time of the data part of the uplink PPDU, that is, the time when the sub-channel is used to transmit data.

Optionally, if space reuse can be performed, the AP1 can set the channel state to be idle, or the MAC of the AP1 can restore the channel backoff. The physical layer PHY of AP1 can send PHY-CCA.indication(idle), and after receiving PHY-CCA.indication(idle), the MAC of AP1 can resume the enhanced distributed channel access (Enhanced Distributed Channel Access, EDCA) backoff process.

Optionally, the station determines, according to the RSSI2, whether contention access to the target channel can be performed, including:

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

If the RSSI2 is less than the second threshold, the station determines that contention access to the target channel can be performed.

In the embodiment of the present invention, the RSSI2 is compared with the second threshold. If the RSSI2 is greater than the second threshold, the station determines that it cannot compete for access to the target channel. If the RSSI2 is less than the second threshold, the station determines that it can compete to access the target channel. . The size of the second threshold mainly depends on the interference that the local station can tolerate if it transmits. For example, as shown in Figure 4, the size of the second threshold mainly depends on whether AP1 transmits and can tolerate interference when STA2 transmits data in uplink. STA2 is a half-duplex node. When STA2 sends uplink PPDUs, it only sends but does not receive.

Optionally, the station can further determine whether it can compete for access to the target channel in combination with other conditions. For example, the station can determine whether it can compete for access to the target channel according to whether a trigger frame is received, or the signal strength of the received trigger frame. :

If RSSI2 is less than the second threshold, and the station does not receive the trigger frame (that is, it indicates that AP1 will not interfere with the reception of AP2), it is determined that the target channel can be competed for access; or,

If RSSI2 is less than the second threshold, and the received signal strength of the trigger frame received by the station is relatively small (that is, it indicates that the interference caused by AP1 to AP2 is relatively small), it is determined that the target channel can be competed for access.

S206, if possible, the station competes to access the target channel;

In the embodiment of the present invention, if it is determined according to RSSI2 that the target channel can be accessed, the station competes to access the target channel for spatial reuse. As shown in the schematic diagram of the time axis in FIG. 4 , AP1 starts to back off from the contention access after the AIFS interval. The target channel is spatially reused.

Optionally, there may be multiple access modes for the stations to compete to access the target channel. The following two optional implementation modes are used as examples to illustrate:

In a first optional implementation manner, the station competes for access to the target channel, including the following two steps:

Step 1, the station detects the signal strength of the signal carried by the target channel;

Step 2: If the signal strength is less than a third threshold, the station competes to access the target channel.

In the embodiment of the present invention, when the STA receives a physical PHY preamble, if the detected format is HE-PPDU, a clear channel assessment (Clear Channel Assessment, CCA) is performed in the HE-Data phase, and CCA is used to detect whether it can compete for access. into the target channel.

Optionally, one of the methods of CCA detection is to detect the signal strength of the signal carried by the target channel. Since all OBSS sites belonging to STA2 are performing spatial reuse detection during the process of STA2 sending the uplink PPDU, there may be multiple The station has accessed the target channel. In order to ensure the quality of signal transmission, in this embodiment of the present invention, the station detects the signal strength of the signal carried by the current target channel through the CCA detection technology. If the signal strength is less than the third threshold, it means that the For contention access, the station backs off contention to access the target channel.

Optionally, if the signal strength is greater than the third threshold, the station suspends backing off until the uplink PPDU transmission ends, or the station suspends backing off until the uplink PPDU transmission ends and a fixed offset is added, the fixed offset. The size is determined by the protocol, or the station suspends the backoff until the transmission of the acknowledgement frame corresponding to the uplink PPDU ends.

In the second optional implementation manner, in order to be able to control the number of stations that perform spatial reuse in the target channel, this 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 the maximum allowable backoff threshold value, the first indication frame includes a beacon frame or a management frame, and the maximum allowable backoff threshold value is included in the first indication frame. The backoff threshold value is used to indicate the maximum backoff times of the station;

In the embodiment of the present invention, as shown in FIG. 4 , in order to control the number of stations that perform spatial reuse on the target channel, AP2 sends a first indication frame, the first indication frame may be a beacon frame or a management frame, and the first indication frame The indication frame contains a target field used to indicate the maximum allowable back-off threshold value. The maximum allowable back-off threshold value is used to indicate the maximum back-off times of the site. For example, if the maximum allowable back-off threshold value is 16, it indicates the maximum back-off of the site. The number of times is 16.

Further optionally, the indication manner for indicating the maximum backoff threshold value by the target field may include various manners, which are 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 can be obtained value, or, the target field may also include a reference value for representing the maximum allowable backoff threshold value, and the maximum backoff threshold value is determined by the reference value and the value of the preset field in the uplink PPDU. It should be noted that, The preset field may include one or more, the value of the preset field may be a coefficient, and the maximum backoff threshold value may be the product or addition of the reference value and the system, etc. can be set.

Based on the above-mentioned first indication frame, the station competes for access to the target channel, including the following four steps:

Step 1. The site generates a random backoff value, and the random value for backoff belongs to a preset range;

Step 2: The station performs backoff based on the backoff random value, and if the backoff is completed within the allowable range of the maximum allowable backoff threshold, the station accesses the target channel.

Step 3, if the station does not complete the backoff within the allowable range of the maximum allowable backoff threshold, the station suspends backoff until the end time related to the uplink PPDU;

Step 4: When the end time related to the uplink PPDU is reached, the station detects whether the target channel is idle, and if it is idle, resumes backoff.

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

When the station AP1 detects that the space reuse is allowed, it starts to back off. The specific back off method is as follows: a carrier sense multiple access (CSMA) back off counter of the station generates a random back off value, and the back off random value belongs to The preset range, for example, the preset range is 0 to 63.

The station backs off based on the random backoff value, and the random backoff value is reduced by 1 for each backoff. The maximum backoff threshold value in the first indication frame indicates the maximum backoff times. When the station backs off the maximum backoff times, the random backoff value remains the same. If it does not reach 0, it means that the backoff has not been completed. If the number of times the station backs off is less than or equal to the maximum backoff times, the random backoff value returns to 0, indicating that the backoff is completed. When the station completes the backoff, it can access the target channel.

In the embodiment of the present invention, if the station does not complete the backoff within the allowable range of the maximum allowable backoff number threshold, the backoff is suspended. Until the end time related to the upstream PPDU, when the end time related to the upstream PPDU is reached, the busy-idle condition of the target channel is detected again, and if the channel is free, the backoff is resumed.

Through the above method, the number of sites for spatial reuse in the target channel can be controlled. As shown in Figure 6, for example, the random value of a CSMA backoff counter of a site ranges from 0 to 63, and the maximum allowable backoff threshold is 16. The maximum allowable back-off number threshold value has a maximum probability of 16/64=1/4 for spatial reuse in the transmission process of this STA2.

AP2 can control the expected value of the number of stations for spatial reuse through the maximum allowable backoff number threshold value, so as to avoid interference exceeding the allowable range of OBSS. The AP can obtain the OBSS interference situation (interference fluctuation variance, interference power, wireless packet loss probability, etc.) through AP-AP information exchange or AP-AC-AP information exchange.

As shown in Figure 6, it is a schematic diagram of another channel access scenario provided by the embodiment of the present invention. As shown in the figure, both AP1 and AP3 detect that STA2 can perform spatial reuse during the transmission process, but AP2 can indicate the maximum allowable The backoff threshold value is used to control the number of stations that perform space sharing. For example, AP2 can control any one of AP1 and AP3 to compete for access to the target channel for space sharing.

As shown in the schematic diagram of the time axis in Figure 6, both AP1 and AP3 perform backoff, AP1 completes backoff within the allowable range of the maximum allowable backoff threshold, and competes to access the target channel for spatial reuse, while AP3 does not backoff within the maximum allowable backoff threshold The backoff is completed within the allowable range of the threshold value, so AP3 suspends backoff until the end of PPDU transmission, and performs backoff access after the interval AIFS.

S207, the station determines, 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.

In this embodiment of the present invention, 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 measured RSSI1, and the downlink PPDU may be a reply to the uplink PPDU ACK or MU-BA, the frequency domain resource used by the downlink PPDU is not limited in the present invention, and may be the full-band frequency domain resource of the target channel or the frequency domain resource of at least one subchannel. As shown in FIG. 4 , RSSI1 may indicate the interference between AP1 and STA2 in the target frequency domain resource.

Optionally, the station determines whether the end time of accessing the target channel can exceed the start time of downlink PPDU transmission adjacent to the uplink PPDU according to the RSSI1, including:

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 downlink PPDU transmission 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 downlink PPDU transmission adjacent to the uplink PPDU.

In this embodiment of the present invention, if RSSI1 is less than the first threshold, it means that the interference between the station and sending the uplink PPDU is relatively small. As shown in FIG. 4 , if RSSI1 is less than the first threshold, it means that AP1 sends and receives data to STA2 for receiving downlink PPDUs. (eg ACK/BA) will not cause strong interference, and the end time of AP1 accessing the target channel for spatial reuse may exceed the transmission start time of the downstream PPDU adjacent to the upstream PPDU. As shown in the time axis of Fig. 4, the time for AP1 to perform spatial reuse exceeds the start time of ACK/BA transmission.

If RSSI1 is greater than the first threshold, it means that the interference between the station and sending the uplink PPDU is relatively strong. As shown in Figure 5, if RSSI1 is greater than the first threshold, it means that AP1 sends and receives data to STA2 and receives downlink PPDUs (such as ACK/BA). It will cause strong interference, and the end time of 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 AP1 to perform spatial reuse does not exceed the start time of ACK/BA transmission, and within the ACK/BA transmission period, the channel is set to be busy.

Further optionally, the directions of the first signal and the second signal can be changed, for example, the first signal is sent omnidirectionally, and the second signal is sent omnidirectionally (as shown in FIG. The signal is sent omnidirectionally, and the field signal sent 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. The field signal sent by the full-band frequency domain resource is omnidirectional sending, and the field signal sent by using one of the subchannel frequency domain resources is directional sending); or, the first signal is sent directionally, and the second signal is sent directionally (as shown in Figure 3 ) As shown, the field signal sent using the full-band frequency domain resources of the target channel is directional sending, and the field signal sent using one of the sub-channel frequency domain resources is also directional sending). The present invention uses a preset field to indicate whether the beam directions of the first signal and the second signal change. Optionally, use the BeamChange bit indication in the uplink PPDU.

As shown in FIG. 4 , if AP1 detects that the received PPDU is an uplink PPDU and is triggered for transmission, and the first basic service set identifier in the preamble of the PPDU is different from the second basic service set identifier of AP1, AP1 NAV is not set by the TXOP holder of the BSS or AP1 is not set by the TXOP holder of the OBSS. During the measurement process, RSSI1 is less than the first threshold, the Beam Change bit is set to indicate that the beam direction does not change, the second If the threshold is greater than or equal to the first threshold, then AP1 can directly determine according to RSSI1 that space reuse can be performed, and the end time of space reuse can exceed the start time of downlink PPDU (ACK/BA) transmission. AP1 can set the channel state to idle. The STA's MAC can recover the channel backoff. The physical layer PHY of the STA can send PHY-CCA.indication(idle), and the MAC of the STA can resume the EDCA backoff process after receiving the PHY-CCA.indication(idle). It should be noted that if the second threshold is smaller than the first threshold, it means that space reuse cannot be performed.

If AP1 detects that the received PPDU is an uplink PPDU and is a triggered transmission, and the BSS color in the preamble of the PPDU is different from the BSS color of AP1, AP1 is not set to NAV by the TXOP holder of the BSS or AP1 is not set to OBSS The TXOP holder sets the NAV. During the measurement process, RSSI1 is greater than the first threshold, and the Beam Change bit is set to indicate that the beam direction changes, then AP1 needs to further measure RSSI2 to determine whether to compete for access to the target channel.

Further optionally, the basic service set identifier can be the basic service set color BSS Color, then the BSS Color of the basic service set BSS can be updated, so the channel access method of this embodiment may further include the following steps S206-S208;

S208, the station receives a second indication frame, where the second indication frame includes the 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;

In the embodiment of the present invention, the BSS Color of the site can be updated, the BSSID refers to the MAC address of the site, and the BSS is defined by the IEEE 802.11-1999 wireless local area network specification. This area uniquely defines each BSS. The BSSID is a locally administered IEEE MAC address, generated from a 46-bit arbitrary code. The individual/group bits of the address are set to 0 and the general/local address bits are set to 1. All STAs in a BSS store the BSSID of the AP in the BSS. When the BSS Color of the AP in a BSS is updated, a second indication frame is sent, and the second indication frame includes the first BSSID of the AP.

S209, the site matches the first BSSID with the second BSSID of the site;

In the 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.

S210, if the matches are consistent, the site updates the second BSS Color to the updated BSS Color.

In the embodiment of the present invention, if the matches are consistent, it means that the BSS Color of the AP associated with the site has been updated, and therefore the site updates its own BSS Color.

In this embodiment of the present invention, when a station receives a PPDU on a target channel, it detects whether the PPDU is an uplink PPDU, and if it is an uplink PPDU, it measures RSSI1 based on the first signal, and further acquires the first basic service set identifier in the PPDU preamble signal. , measure RSSI2 based on the second signal, compare whether the first basic service set identifier is consistent with the second basic service set identifier of the site, if not, determine whether the contention access of the target channel can be performed according to RSSI2, if so, the competition Access the target channel, and further determine whether the end time of the access target channel can exceed the start time of downlink PPDU transmission according to RSSI1, which not only ensures no interference to uplink PPDU transmission, but also ensures no interference to downlink PPDU transmission.

The specific implementation of the site provided by the embodiment of the present invention is described below with reference to FIG. 7 to FIG. 8 .

Please refer to FIG. 7 , which is a schematic structural diagram of a site provided by an embodiment of the present invention. As shown in FIG. 7 , a site described in this embodiment includes: a receiving module 100 , a processing module 101 , and a channel access module 102 .

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

Optionally, the site is an access site AP or a non-access site. As shown in Figure 1, the site is a non-access site STA1, and STA1 and STA2 are each other's OBSS sites; as shown in Figure 4, the site is It is an access type site AP1, and the AP1 and STA2 are also OBSS sites for each other.

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

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

Optionally, the first signal includes L-STF and L-LTF in the upstream PPDU preamble signal. The first signal is sent on the target frequency domain resource of the target channel, for example, the L-STF in the upstream PPDU preamble signal, and the L-LTF adopts the full-band transmission of the target channel.

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

Optionally, the basic service set identifier may be a BSSID, or a basic service set color BSS Color, or other cell identifiers, etc., which are not limited here, and the basic service set identifier is used to distinguish adjacent BSSs.

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

Optionally, the station measures the second received signal strength RSSI2 based on the second signal in the uplink PPDU, and the frequency domain resources used by the second signal are all or part of the 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. HE-STF, HE-LTF, and HE-DATA use sub-channel transmission, and L -STF, L-LTF adopts the full-band transmission of the target channel, and the bandwidth resources used by HE-STF, HE-LTF, and HE-DATA are part of the bandwidth resources used by L-STF and L-LTF.

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

The processing module 101 is further configured to, if the first basic service set identifier is inconsistent with the second basic service set identifier of the station, determine whether contention access to the target channel can be performed according to the RSSI2;

Specifically, optionally, the processing module 101 determines, according to the RSSI2, whether contention access to the target channel can be performed, which specifically includes:

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

If the RSSI2 is less than the second threshold, the processing module 101 determines that contention access to the target channel can be performed.

Optionally, the station can further determine whether it can compete for access to the target channel in combination with other conditions. For example, the station can determine whether it can compete for access to the target channel according to whether a trigger frame is received, or the signal strength of the received trigger frame. :

If RSSI2 is less than the second threshold, and the station does not receive the trigger frame (that is, it indicates that AP1 will not interfere with the reception of AP2), it is determined that the target channel can be competed for access; or,

If RSSI2 is less than the second threshold, and the received signal strength of the trigger frame received by the station is relatively small (that is, it indicates that the interference caused by AP1 to AP2 is relatively small), it is determined that the target channel can be competed for access.

a channel access module 102, configured to compete for access to the target channel if the target channel can be competed for access;

Optionally, the access manner of the channel access module 102 competing for access to the target channel may include the following two optional implementation manners:

In a first optional implementation manner, the channel access module 102 competing for access to the target channel specifically includes:

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

If the signal strength is less than the third threshold, the channel access module 102 competes for access to 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 used to indicate the maximum allowable backoff threshold value, and the first indication frame An indication frame includes a beacon frame or a management frame, and the maximum allowable backoff threshold is used to indicate the maximum backoff times of the station;

Optionally, the target field includes the maximum allowable backoff threshold; or,

The target field includes a reference value 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 channel access module 102 competing for access to 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;

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

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

When reaching the end time related to the transmission of the PPDU, the channel access module 102 detects whether the target channel is idle, and if it is idle, resumes backoff.

Optionally, the end time related to the uplink PPDU includes the end of the signal transmission of the uplink PPDU, or the end of the transmission of the acknowledgment frame corresponding to the uplink PPDU, or the addition of the signal after the end of the uplink PPDU signal transmission. An offset time.

The processing module 101 is further configured to determine, 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.

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

If the RSSI1 is less than the first threshold, the processing module 101 determines that the end time of accessing the target channel can exceed the start time of the downlink PPDU transmission 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 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 sent omnidirectionally, and the second signal is sent omnidirectionally; or, the first signal is sent omnidirectionally, and the second signal is sent directionally; One signal is sent directionally, and the second signal is sent directionally. The present invention uses a preset field to indicate whether the beam directions of the first signal and the second signal change. Optionally, use the Beam Change bit indication in the uplink PPDU.

If AP1 detects that the received PPDU is an uplink PPDU and is a triggered transmission, and the BSS color in the preamble of the PPDU is different from the BSS color of AP1, AP1 is not set to NAV by the TXOP holder of the BSS or AP1 is not set to OBSS The TXOP holder sets the NAV. During the measurement process, RSSI1 is less 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, then AP1 can directly determine according to RSSI1 that it can perform Space reuse, and the end time of space reuse may exceed the start time of downlink PPDU (ACK/BA) transmission. AP1 can set the channel state to idle. The STA's MAC can recover the channel backoff. The physical layer PHY of the STA can send PHY-CCA.indication(idle), and the MAC of the STA can resume the EDCA backoff process after receiving PHY-CCA.indication(idle). It should be noted that if the second threshold is smaller than the first threshold, it means that space reuse cannot be performed.

If AP1 detects that the received PPDU is an uplink PPDU and is a triggered transmission, and the BSS color in the preamble of the PPDU is different from the BSS color of AP1, AP1 is not set to NAV by the TXOP holder of the BSS or AP1 is not set to OBSS The TXOP holder sets the NAV. During the measurement process, RSSI1 is greater than the first threshold, and the Beam Change bit is set to indicate that the beam direction changes, then AP1 needs to further measure RSSI2 to determine whether to compete for access to the target channel.

Further optionally, the basic service set identifier is the service set color BSS Color, and the BSS Color of the site can be updated, and the update method is as follows:

The receiving module 100 is further configured to receive a second instruction frame, where the second instruction frame includes the 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;

The processing module 101 is further configured to match the first BSSID with the second BSSID of the site;

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

In this embodiment of the present invention, when a station receives a PPDU on a target channel, it detects whether the PPDU is an uplink PPDU, and if it is an uplink PPDU, it measures RSSI1 based on the first signal, and further acquires the first basic service set identifier in the PPDU preamble signal. , measure RSSI2 based on the second signal, compare whether the first basic service set identifier is consistent with the second basic service set identifier of the site, if not, determine whether the contention access of the target channel can be performed according to RSSI2, if so, the competition Access the target channel, and further determine whether the end time of the access target channel can exceed the start time of downlink PPDU transmission according to RSSI1, which not only ensures no interference to uplink PPDU transmission, but also ensures no interference to downlink PPDU transmission.

It can be understood that, for the specific implementation manner of each module in the above site, reference may be made to the relevant description in the method embodiment.

Please refer to FIG. 8 , which is a schematic structural diagram of another site provided by an embodiment of the present invention. The site 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 .

Specifically, the processor 1010 controls the operation of the site 1000 . Memory 1020, which may include read-only memory and random access memory, provides instructions and data to processor 1010, which may be a general purpose processor, digital signal processor, application specific integrated circuit, field programmable gate array, or other programmable logic device. A portion of memory 1020 may also include non-volatile row random access memory (NVRAM). The baseband circuit 1030 is used to synthesize the baseband signal to be transmitted, or to decode the received baseband signal, such as L-SIG, R-L-SIG, HE-SIG-A, HE-SIG- B to decode. The radio frequency circuit 1040 is used to modulate the low frequency baseband signal to the high frequency carrier signal, and the high frequency carrier signal is transmitted through the antenna 1050 . The radio frequency circuit is also used to demodulate the high frequency signal received by the antenna 1050 into a low frequency carrier signal. Various components of the station 1000 are coupled together through a bus 1060, wherein the bus system 1060 includes a power bus, a control bus and a status signal bus in addition to a data bus. However, for clarity of illustration, the various buses are labeled as bus system 1060 in the figure. It should be noted that, the foregoing description of the site structure may be applied to subsequent embodiments.

The radio frequency circuit 1040 is used for receiving the physical layer protocol data unit PPDU on the target channel;

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

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

The processor 1010 is further configured to acquire the first basic service set identifier in the PPDU preamble signal;

The processor 1010 is further configured to measure the second received signal strength RSSI2 based on the 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;

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

If inconsistent, the processor 1010 is further configured to determine, according to the RSSI2, whether contention access to the target channel can be performed;

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

The processor 1010 is further configured to determine, 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.

Optionally, the above-mentioned processor 1010 determines, according to RSSI2, whether contention access to the target channel can be performed, specifically:

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

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

The above-mentioned first signal includes the traditional short training field L-STF and the traditional long training field L-LTF in the upstream PPDU preamble signal;

The above-mentioned second signal includes at least one of the high-efficiency short-training training field HE-STF, the high-efficiency long-training training field HE-LTF and the high-efficiency data field HE-DATA in the uplink PPDU.

The above-mentioned downlink PPDU includes an acknowledgement frame (Acknowledgement, ACK) or a multi-user block acknowledgment (Multi-block acknowledgment, MU-BA) for the uplink PPDU.

Optionally, the processor 1010 determines, according to RSSI2, whether contention access to the target channel can be performed, specifically:

If RSSI2 is greater than the second threshold, the processor 1010 determines that contention access to the target channel cannot be performed; that is, spatial reuse cannot be performed;

If RSSI2 is less than the second threshold, the processor 1010 determines that contention access to the target channel can be performed, that is, spatial reuse can be performed.

The above comparison between RSSI2 and the second threshold can determine whether the uplink PPDU transmission will cause interference to the station sending and receiving data, so as to determine whether to perform space sharing within the uplink PPDU transmission time.

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

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

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

Optionally, the processor 1010 competing for access to the target channel specifically includes:

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

If the signal strength is less than the third threshold, the processor competes for access to the target channel.

Further optionally, if the signal strength is greater than the third threshold, the station suspends the backoff until the end of the uplink PPDU transmission or suspends the 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 the maximum allowable backoff threshold, the first indication frame includes a beacon frame or a management frame, and the maximum The allowable backoff threshold is used to indicate the maximum backoff times of the station;

The target field includes the maximum allowable backoff threshold; or,

The target field includes a reference value 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.

Optionally, the processor 1010 competing for access to the target channel specifically includes:

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

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

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

When reaching the end time related to the uplink PPDU, the processor detects whether the target channel is idle, and if it is idle, it resumes backoff.

Optionally, the end time related to the uplink PPDU includes the end of the signal transmission of the uplink PPDU, or the end of the transmission of the acknowledgment frame corresponding to the uplink PPDU, or the addition of the signal after the end of the uplink PPDU signal transmission. An offset time.

Optionally, the radio frequency circuit 1040 receives a second indication frame, where the second indication frame includes a first basic service set identifier (Basic Service Set Identifier, BSSID) and a characteristic field used to indicate the BSS Color update, and the characteristic field carries the updated BSS Color. BSS Color;

The processor 1010 matches the first BSSID with the second BSSID of the site;

If the matches are consistent, the processor 1010 updates the second BSS Color to the above-mentioned updated BSS Color.

Optionally, the above-mentioned uplink PPDU may further include a preset field, where the preset field is used to indicate that the beam direction of the above-mentioned first signal and the above-mentioned second signal are changed;

Before measuring the second received signal strength RSSI2 based on the second signal in the PPDU, the processor 1010 further includes:

If it is detected that the preset field indicates that the beam directions for transmitting the first signal and the second signal are different, the processor 1010 measures RSSI2 based on the second signal in the PPDU.

If the station detects that the preset field indicates that the beam directions for sending the first signal and the second signal are the same, the processor 1010 determines, according to the RSSI1, whether contention access to the target channel can be performed and whether the end time of accessing the target channel is not It can exceed the start time of the transmission of the downstream PPDU adjacent to the upstream PPDU.

In this embodiment of the present invention, when a station receives a PPDU on a target channel, it detects whether the PPDU is an uplink PPDU, and if it is an uplink PPDU, it measures RSSI1 based on the first signal, and further acquires the first basic service set identifier in the PPDU preamble signal. , measure RSSI2 based on the second signal, compare whether the first basic service set identifier is consistent with the second basic service set identifier of the site, if not, determine whether the contention access of the target channel can be performed according to RSSI2, if so, the competition Access the target channel, and further determine whether the end time of the access target channel can exceed the start time of downlink PPDU transmission according to RSSI1, which not only ensures no interference to uplink PPDU transmission, but also ensures no interference to downlink PPDU transmission.

It can be understood that, for the specific implementation manner of each component in the foregoing site, reference may be made to the related descriptions in the method embodiments.

Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be implemented by instructing relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. During execution, the processes of the embodiments of the above-mentioned methods may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM), or a random access memory (Random Access Memory, RAM) or the like.

The steps in the method of the embodiment of the present invention may be adjusted, combined and deleted in sequence according to actual needs.

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

Components such as the microcontroller in 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 (Application Specific Integrated Circuit, ASIC).

The above disclosures are only preferred embodiments of the present invention, and of course, the scope of the rights of the present invention cannot be limited by this. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims (20)

1. A channel access method, comprising: When the station receives the physical layer protocol data unit PPDU on the target channel, it detects whether the PPDU is an uplink PPDU; If it is an uplink PPDU, the station measures the first received signal strength RSSI1 based on the first signal in the PPDU preamble signal, and the first signal is sent in the target frequency domain resource of the target channel; obtaining, by the station, the first basic service set identifier in the PPDU preamble signal; The station measures the second received signal strength RSSI2 based on the second signal in the PPDU, and the frequency domain resources used by the second signal are all or part of the target frequency domain resources; the site compares whether the first basic service set identifier is consistent with the second basic service set identifier of the site; If not, the station determines whether the RSSI2 is less than the second threshold, and whether the received signal strength of the trigger frame used to trigger the uplink PPDU received by the station is less than the fourth threshold, and determines whether the target channel can be processed contention access. 2. The method of claim 1, wherein the station determines whether the RSSI2 is less than a second threshold, and whether the received signal strength of the trigger frame for triggering the uplink PPDU received by the station is less than The fourth threshold, determining whether contention access to the target channel can be performed, includes: The station determines that the RSSI2 is less than the second threshold, and the received signal strength of the trigger frame for triggering the uplink PPDU received by the station is less than the fourth threshold, and determines that contention access to the target channel can be performed. 3. The method according to claim 1 or 2, wherein the station judges whether the RSSI2 is less than a second threshold, and whether the received signal strength of the trigger frame for triggering the uplink PPDU received by the station is whether If it is less than the fourth threshold, after determining whether contention access to the target channel can be performed, the method includes: If the station determines that the target channel can be competed for access, the station competes to access the target channel; The station determines, 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. 4. The method of claim 1, wherein the first signal comprises a traditional short training field L-STF and a traditional long training field L-LTF in the uplink PPDU; 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. 5. The method of claim 4, wherein 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 RSSI1, include: 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 downlink PPDU transmission 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 downlink PPDU transmission adjacent to the uplink PPDU. 6. The method of claim 1, wherein the station contends for access to the target channel, comprising: The station detects the signal strength of the signal carried by the target channel; If the signal strength is less than a third threshold, the station competes for access to the target channel. 7. The method of claim 1, wherein the method further comprises: The station receives a first indication frame, the first indication frame includes a target field for indicating the maximum allowable backoff threshold, the first indication frame includes a beacon frame or a management frame, and the maximum allowable backoff threshold The limit is used to indicate the maximum number of backoffs for the site; The station contends for access to the target channel, including: The station generates a random backoff value, and the random value for backoff belongs to a preset range; The station performs backoff based on the backoff random value, and if the backoff is completed within the allowable range of the maximum allowable backoff threshold, the station accesses the target channel. 8. The method of claim 7, wherein the target field comprises the maximum allowable backoff threshold; or, The target field includes a reference value for representing the maximum allowable back-off threshold value, and the maximum allowable back-off threshold value is determined by the reference value and a value of a preset field in the uplink PPDU. 9. The method of claim 8, further comprising: If the station does not complete the back-off within the allowable range of the maximum allowable back-off threshold, the station suspends back-off until the end time related to the uplink PPDU; When reaching the end time related to the uplink PPDU, the station detects whether the target channel is idle, and if it is idle, resumes backoff; The end time related to the uplink PPDU includes the end of the signal transmission of the uplink PPDU, or the end of the transmission of the acknowledgement frame corresponding to the uplink PPDU, or an offset is added after the signal transmission of the uplink PPDU ends. time. 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, and the second indication frame includes the first basic service set identifier BSSID and a characteristic field for indicating that the BSS Color is updated, and the characteristic field carries the updated BSS Color; The site matches the first BSSID with the second BSSID of the site; If the matches are consistent, the site updates the BSS Color to the updated BSS Color. 11. A site comprising: The radio frequency circuit is used for receiving the physical layer protocol data unit PPDU on the target channel; a processor for detecting whether the PDU is an uplink PPDU; The processor is further configured to measure the first received signal strength RSSI1 based on the first signal in the PPDU preamble signal if it is an uplink PPDU, and the first signal is sent in the target frequency domain resource of the target channel; The processor is further configured to obtain the first basic service set identifier in the PPDU preamble signal; The processor is further configured to measure the second received signal strength RSSI2 based on the 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; The processor is further configured to compare whether the first basic service set identifier is consistent with the second basic service set identifier of the site; If not, the processor is further configured to determine whether the RSSI2 is less than a 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 determine whether the process can be performed contention access to the target channel. 12 . The station according to claim 11 , wherein the processor is specifically configured to judge that the RSSI2 is less than a second threshold, and the station receives a received signal for triggering a trigger frame of the uplink PPDU. 12 . When the strength is less than the fourth threshold, it is determined that contention access to the target channel can be performed. 13. The station according to claim 11 or 12, wherein the processor is further configured to compete for access to the target channel if the target channel can be competed for access; The processor is further configured to determine, 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. 14. The station according to claim 11, wherein the first signal comprises a traditional short training field L-STF and a traditional long training field L-LTF in the upstream PPDU preamble signal; The second signal includes at least one of a high-efficiency short-training training field HE-STF, a high-efficiency long-training training field HE-LTF and a high-efficiency data field HE-DATA in the uplink PPDU. 15. The site of claim 14, wherein the processor 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 RSSI1, and specifically includes: The processor judges that RSSI1 is less than the first threshold, and determines that the end time of accessing the target channel can exceed the start time of downlink PPDU transmission adjacent to the uplink PPDU; The processor determines that RSSI1 is greater than the first threshold, and determines that the end time of accessing the target channel cannot exceed the start time of transmission of the downlink PPDU adjacent to the uplink PPDU. 16. The station according to claim 12, wherein the processor competing for access to the target channel specifically comprises: The processor detects the signal strength of the signal carried by the target channel; If the signal strength is less than the third threshold, the processor competes for access to the target channel. 17. The station of claim 11, wherein the radio frequency circuit is further configured to receive a first indication frame, wherein the first indication frame includes a target field for indicating a maximum allowable backoff threshold, the first The indication frame includes a beacon frame or a management frame, and the maximum allowable backoff threshold is used to indicate the maximum backoff times of the station; The processor competing for access to the target channel specifically includes: The processor generates a backoff random value, and the backoff random value belongs to a preset range; The processor performs backoff based on the backoff random value, and if backoff is completed within the allowable range of the maximum allowable backoff threshold value, the station accesses the target channel. 18. The station of claim 17, wherein the target field includes a maximum allowable backoff threshold; or, The target field includes a reference value for representing the maximum allowable backoff threshold value, and the maximum allowable backoff threshold value is determined by the reference value and the value of a preset field in the uplink PPDU, and the value of the preset field is a coefficient. 19. The station according to claim 18, wherein if the station does not complete backing within the maximum allowable back-off threshold value allowable range, then the processor controls the station to suspend back-off until the end relevant to the uplink PPDU time; When reaching the end time related to the uplink PPDU, the processor detects whether the target channel is idle, and if it is idle, resumes backoff. 20. The site of claim 11, wherein the basic service set identifier is a service set color BSSColor; The radio frequency circuit receives the second instruction frame, and the second instruction frame includes the first basic service set identifier (BasicService Set Identifier, BSSID) and a feature field for indicating that the BSS Color is updated, and the feature field carries the updated BSS Color; The processor matches the first BSSID with the second BSSID of the site; If the matches are consistent, the processor updates the BSS Color to the above-mentioned updated BSS Color.

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