Patent Description:
With development of mobile Internet and popularity of smart terminals, data traffic presents an explosive growth trend. Currently, a wireless local area network (WLAN) becomes one of mainstream mobile broadband access technologies with advantages of a high rate and low costs.

11ac-based wireless local area network (WLAN) system is briefly referred to as an <NUM>. 11ac system, and the <NUM>. 11ac system uses an orthogonal frequency division multiplexing (OFDM) modulation scheme. 11ac system may include multiple basic service sets (BSSs), and each BSS may include one access point (AP) and one station (STA) associated with the AP. When the AP or the STA needs to transmit data, the AP or the STA may detect signal detection energy of a current channel. If the signal detection energy is less than a clear channel assessment (CCA) threshold, the AP or the STA contends for the channel, and transmits the data when the channel contention succeeds.

A next-generation WLAN system <NUM>. 11ax may introduce a spatial reuse technology to improve use efficiency of system resources. An AP or a STA may increase a CCA threshold. In this way, spatial simultaneous transmission can be performed on a link on which simultaneous transmission cannot be performed originally, thereby enhancing a network throughput.

In an <NUM>. 11n/ac system, a NAV (network allocation vector) setting manner is as follows: After receiving a data packet, a node determines whether a receiver address of the data packet is the node. If the receiver address of the data packet is not the node, the node determines a relationship between a decoded duration field and a current NAV. If the field is greater than a current NAV value, the node updates the NAV.

Due to the introduced spatial reuse technology, if the CCA threshold is increased, it indicates that the system supports that the node performs spatial reuse. However, if the node determines that a current CCA is idle, according to an original NAV mechanism, the node needs to update the NAV according to the decoded duration field, and the node still cannot perform spatial reuse. Consequently, enhancing a system throughput is affected. <CIT> describes a method, wherein a first transmitter determines whether to permit reuse of a first transmit opportunity (TXOP) associated with a message. The method further includes sending a portion of the message from the first transmitter to a first receiver. The portion of the message indicates whether reuse, by a reuse transmitter, of the first TXOP is permitted. When reuse of the first TXOP is permitted, the reuse transmitter is permitted to send a second message while the first transmitter sends a second portion of the message to the first receiver during the first TXOP. <CIT> describes an operation method and apparatus using a sectorized transmission opportunity in a wireless LAN system. The method by which a STA performs a transmission opportunity-based (TXOP-based) sectorization operation in a wireless LAN system comprises the steps of: determining whether an ongoing frame exchange is transmitted within a BSS of the STA or within an overlapping BSS (OBSS); determining whether spatially orthogonal (SO) conditions are met; and resetting a virtual carrier sensing (VCS) value of the STA, if the ongoing frame exchange is transmitted within the OBSS and the SO conditions are met. <CIT> describes a medium access control (MAC) protocol for avoiding collisions among ESTAs when two or more OBSSs co-exist and operate in the same channel. To achieve this, each mobile station operating under HCF maintains a first counter known as NAV and a second counter known as Overlapping NAV (ONAV), which is updated within a mobile station by frames coming from OBSSs, during the Contention Free Period (CFP) or during a Contention Free Burst (CFB) granted by a polling frame. The mobile station uses the NAV to update only to the medium occupancy in its own BSS to ensure that the mobile station will not interfere with the transmissions in its own QBSS, while the ONAV is used to avoid collisions with the mobile stations from the OBSS.

Embodiments of the present invention provide a computer program for performing a NAV setting method in a wireless communications system and a related computer-readable storage medium, so as to enhance a system throughput.

Advantageous embodiments of the invention are given by the dependent claims.

The present invention mainly designs a NAV mechanism for spatial reuse, so as to increase a spatial reuse capability of a system, and enhance a throughput of an entire network.

The following clearly describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some but not all of the embodiments of the present invention.

Embodiments of the present invention may be applied to a wireless local area network (WLAN). The WLAN may include multiple basic service sets (BSSs). A network node of the BSS is a station (STA), and the station includes an access point station (AP) and a none access point station (Non-AP STA). Each BSS may include one AP and multiple Non-AP STAs associated with the AP. A manner of uplink transmission between an AP and a STA includes but is not limited to an OFDMA manner.

The AP is also referred to as a wireless access point, a hotspot, or the like. The AP is an access point for a mobile user to connect to a wired network, and is mainly deployed inside a home, a building, or a campus. A typical coverage radius ranges from dozens of meters to hundreds of meters. Certainly, the AP may be deployed outdoors. The AP functions as a bridge connecting a wired network and a wireless network. A main function of the AP is to connect clients of a wireless network together, and then to connect the wireless network to Ethernet. Currently, a major standard used by the AP is an IEEE (Institute of Electrical and Electronics Engineers) <NUM> series. Specifically, the AP may be a terminal device or a network device having a WiFi (Wireless Fidelity) chip. Optionally, the AP may be a device supporting an <NUM>. 11ax standard. Further, optionally, the AP may be a device supporting multiple WLAN standards such as <NUM>. 11ac, <NUM>. 11n, <NUM>, <NUM>. 11b, and <NUM>.

The Non-AP STA, briefly referred to as STA below, may be a wireless communications chip, a wireless sensor, or a wireless communications terminal, for example, a mobile phone supporting a WiFi communication function, a tablet computer supporting a WiFi communication function, a set-top box supporting a WiFi communication function, a smart television supporting a WiFi communication function, a smart wearable device supporting a WiFi communication function, or a computer supporting a WiFi communication function. Optionally, the STA may support an <NUM>. 11ax standard. Further, optionally, the STA may support multiple WLAN standards such as <NUM>. 11ac, <NUM>. 11n, <NUM>, <NUM>. 11b, and <NUM>.

In Embodiment <NUM> of the present invention, an access point or a station determines that a received <NUM>. 11ax physical layer protocol data unit (PPDU) is from a WLAN overlapping basic service set (OBSS). If a current clear channel assessment (CCA) threshold of the access point or the station is set to be greater than a preset value, the access point or the station keeps a current NAV value not updated; or when a current clear channel assessment (CCA) threshold of the access point or the station is set to be greater than a preset value, and the node (the access point or the station) detects that an RSSI (received signal strength indicator) of the received PPDU is less than or equal to a CCA threshold or an increased CCA threshold or the node is in a CCA idle state, the access point or the station keeps a current NAV value not updated.

11ax PPDU may include a data frame, or may include a control frame (for example, (e)RTS/(e)CTS/Trigger Frame), a management frame, or the like.

Whether the <NUM>. 11ax PPDU is from the OBSS may be determined according to a BSS color field in HE-SIGA, or according to a receiver address (RA) or a transmitter address (TA) of a MAC header, or by using another method.

The clear channel assessment (CCA) threshold may be a preamble detection /signal detection threshold, an energy detection threshold, or a WiFi signal detection threshold.

The preset value may be a preset or minimum preamble detection/signal detection threshold (for example, may be -<NUM> dBm by default in a system bandwidth of <NUM>, or may be -<NUM> dBm by default in a system bandwidth of <NUM>), and may be specifically a threshold used when a signal preamble is obtained by means of decoding; or may be a preset or minimum energy detection threshold (for example, may be -<NUM> dBm by default in a system bandwidth of <NUM>), and may be specifically a threshold used when a signal or a signal preamble cannot be obtained by means of decoding; or may be a preset or minimum WiFi signal detection threshold (for example, may be -<NUM> dBm by default in a system bandwidth of <NUM>), and may be specifically a threshold used when a signal preamble cannot be obtained by means of decoding but a WiFi or <NUM>. 11ax signal can be determined; or may be another preset threshold.

In Embodiment <NUM> of the present invention, an access point or a station determines that a received <NUM>. 11ax physical layer protocol data unit (PPDU) is from a WLAN overlapping basic service set (OBSS). If a current clear channel assessment (CCA) threshold is equal to or less than a preset value, after decoding the 11ax PPDU of the OBSS to obtain a duration field, the node updates a current NAV value of the node according to value information of the field.

The duration field obtained by means of decoding may be information about a duration field of a MAC header in the PPDU, information about a duration field in HE-SIGA, or the like.

A method for updating the current NAV value of the node according to the value information of the duration field may be: determining whether the value of the duration field is greater than the current NAV, and updating the current NAV if the value of the duration field is greater than the current NAV, or skipping updating the current NAV if the value of the duration field is not greater than the current NAV; or setting the NAV value of the node by using the value of the duration field; or another specified updating method.

In Embodiment <NUM> of the present invention, an access point or a station determines that a received legacy PPDU is from a WLAN OBSS, the access point or the station decodes the legacy PPDU of the OBSS to obtain a duration field, and updates a current NAV value of the node according to value information of the field. A specific updating method may be similar to the method, described in Embodiment <NUM>, for updating the NAV value according to the duration field.

The access point or the station determines that the received legacy PPDU is from the WLAN overlapping basic service set (OBSS). If a current clear channel assessment (CCA) threshold of the access point or the station is set to be greater than a preset value, the access point or the station keeps the current NAV value not updated; or when a current clear channel assessment (CCA) threshold of the access point or the station is set to be greater than a preset value, and the node (the access point or the station) detects that an RSSI (received signal strength indicator) of the received PPDU is less than or equal to an increased CCA threshold or the node is in a CCA idle state, the access point or the station keeps the current NAV value not updated.

The access point or the station determines that the received legacy PPDU is from the WLAN overlapping basic service set (OBSS), and if the current clear channel assessment (CCA) threshold of the access point or the station is less than or equal to a preset value, after the node decodes the legacy PPDU of the OBSS to obtain the duration field, the access point or the station updates the current NAV value of the node according to the value information of the field.

In Embodiment <NUM>, which is not according to the claims, after a node (an access point or a station) receives any PPDU (for example, an 11ax or legacy data frame, control frame, or management frame) from an intra basic service set (intra-BSS), the node determines whether a receiver address of the PPDU is an address of the node itself or includes an address of the node itself, and if the receiver address of the PPDU is the address of the node itself or includes the address of the node itself, the node keeps a current NAV value not updated.

After the node receives any PPDU (for example, an 11ax or legacy data frame, control frame, or management frame) from the intra basic service set (intra-BSS), the node determines whether the receiver address of the PPDU is the address of the node itself or includes the address of the node itself, and if the receiver address of the PPDU is not the address of the node itself or does not include the address of the node itself, after decoding the PPDU to obtain a duration field, the node updates the current NAV value of the node according to value information of the field.

In Embodiment <NUM>, which is not according to the claims, after a node (for example, an access point or a station) receives an 11ax PPDU from an intra basic service set (intra-BSS), the node keeps a current NAV value not updated.

After the node receives a legacy PPDU from the intra basic service set (intra-BSS), the node determines whether a receiver address of the PPDU is an address of the node itself or includes an address of the node itself, and if the receiver address of the PPDU is an address of the node itself or includes an address of the node itself, the node keeps a current NAV value not updated.

After the node receives the legacy PPDU from the intra basic service set (intra-BSS), the node determines whether the receiver address of the PPDU is the address of the node itself or includes the address of the node itself, and if the receiver address of the PPDU is not the address of the node itself or does not include the address of the node itself, after decoding the legacy PPDU to obtain a duration field, the node updates the current NAV value of the node according to value information of the field.

In Embodiment <NUM>, which is not according to the claims, after a node (for example, an access point or a station) receives an 11ax PPDU from an intra basic service set (intra-BSS), the node determines whether an address of the node is a receiver address of RTS or CTS, or is included in a receiver address of RTS or CTS, and if the address of the node is the receiver address of the RTS or CTS, or is included in the receiver address of the RTS or CTS, the node keeps a current NAV value not updated.

After the node receives the 11ax PPDU from the intra basic service set (intra-BSS), the node determines whether the address of the node is the receiver address of the RTS or CTS, or is included in the receiver address of the RTS or CTS, and if the address of the node is not the receiver address of the RTS or CTS, or is not included in the receiver address of the RTS or CTS, after decoding the 11ax PPDU to obtain a duration field, the node updates the current NAV value of the node according to value information of the field.

Embodiment <NUM>, which is not according to the claims, describes that after a node receives any PPDU (for example, an 11ax or legacy data frame, control frame, or management frame) from an intra basic service set (intra-BSS), the node determines whether an address of the node is a receiver address of RTS or CTS, or is included in a receiver address of RTS or CTS, and if the address of the node is the receiver address of the RTS or CTS, or is included in the receiver address of the RTS or CTS, the node keeps a current NAV value not updated.

After the node receives any PPDU (for example, an 11ax or legacy data frame, control frame, or management frame) from the intra basic service set (intra-BSS), the node determines whether the address of the node is the receiver address of the RTS or CTS, or is included in the receiver address of the RTS or CTS, and if the address of the node is not the receiver address of the RTS or CTS, or is not included in the receiver address of the RTS or CTS, after decoding the 11ax PPDU to obtain a duration field, the node updates the current NAV value of the node according to value information of the field.

As shown in <FIG>, with reference to one or more of Embodiment <NUM> to Embodiment <NUM>, Embodiment <NUM> of the present invention provides a NAV setting method in a wireless communications system. The method includes the following steps:.

The condition of allowing simultaneous transmission includes at least one or a combination of the following conditions: a current CCA threshold of the receiving node is set to be greater than a preset value, the node detects that an RSSI of the received PPDU is less than or equal to a CCA threshold or an increased CCA threshold or the node is in a CCA idle state, the receiving node is located in a nearby area of an AP in an intra-BSS, the received PPDU indicates that another node is allowed to perform simultaneous transmission, or the like.

Whether the receiving node is in a nearby area of an AP in an intra-BSS specifically includes the following scenarios:
if an RSSI of a received PPDU of the AP (an AP located in a same BSS as the receiving node) in the intra-BSS is greater than or equal to a preset value, it is determined that the receiving node is located in the nearby area of the AP in the intra-BSS; or if a distance between the receiving node and the AP is less than or equal to a preset value, it is determined that the receiving node is located in the nearby area of the AP in the intra-BSS; or another method is used.

Whether the PPDU received by the receiving node indicates that other nodes except the transmitting node are allowed to perform simultaneous transmission specifically includes the following scenarios:.

For a specific location of the "SR allowed flag" in the PPDU, refer to <FIG>.

In step S04, a specific method for updating the current NAV value of the receiving node according to the value of the duration field is: determining whether the value of the duration field is greater than the current NAV, and updating the current NAV if the value of the duration field is greater than the current NAV, or skipping updating the current NAV if the value of the duration field is not greater than the current NAV; or setting the NAV value of the node by using the value of the duration field; or another specified updating method.

Referring to <FIG>, Embodiment <NUM> of the present invention further provides a communications node <NUM> including a receiver <NUM>, a transmitter <NUM>, a processor <NUM>, and a memory <NUM>.

The receiver <NUM> is configured to receive a PPDU in an OBSS or intra-BSS of a WLAN system, where the PPDU may be an <NUM>. 11ax PPDU or a legacy PPDU.

The processor <NUM> is configured to: determine whether the communications node <NUM> satisfies a condition of allowing simultaneous transmission; and if the condition of allowing simultaneous transmission is satisfied, keep a current NAV value unchanged; or if the condition of allowing simultaneous transmission is not satisfied, decode the received PPDU to obtain a duration field, and update the current NAV value of the receiving node according to a value of the duration field.

The condition of allowing simultaneous transmission includes at least one or a combination of the following conditions: a current CCA threshold of the communications node <NUM> is set to be greater than a preset value, the communications node <NUM> is in a nearby area of an AP in an intra-BSS, the communications node detects that an RSSI of the received PPDU is less than or equal to a CCA threshold or an increased CCA threshold or the node is in a CCA idle state, the received PPDU indicates that another node is allowed to perform simultaneous transmission, or the like.

In Embodiment <NUM> of the present invention, the processor <NUM> may be configured to execute step S02 to step S04, and the memory <NUM> is configured to store a program and data that are required for the processor <NUM> to execute the foregoing steps.

As shown in <FIG>, with reference to one or more of Embodiment <NUM> to Embodiment <NUM>, Embodiment <NUM>, which is not according to the claims, provides a NAV setting method in a wireless communications system. The method includes the following steps:.

In step S14, a specific method for updating the current NAV value of the receiving node according to the value of the duration field may be: determining whether the value of the duration field is greater than the current NAV, and updating the current NAV if the value of the duration field is greater than the current NAV, or skipping updating the current NAV if the value of the duration field is not greater than the current NAV; or setting the NAV value of the node by using the value of the duration field; or another specified updating method.

Referring to <FIG>, Embodiment <NUM> of the present application further provides a communications node <NUM> including a receiver <NUM>, a transmitter <NUM>, a processor <NUM>, and a memory <NUM>.

The receiver <NUM> is configured to receive a PPDU sent by a transmitting node, where the PPDU may be an <NUM>. 11ax PPDU or a legacy PPDU, and may be a PPDU from an intra-BSS of a WLAN system.

The processor <NUM> is configured to: determine whether the communications node <NUM> satisfies a condition of not updating a NAV, where the condition of not updating a NAV includes any one or a combination of the following conditions: the received PPDU includes an address of the communications node itself, the received PPDU is an <NUM>. 11ax PPDU, a receiver address of RTS or CTS received by the communications node includes an address of the communications node, or the like; and if the condition of not updating a NAV is not satisfied, decode, by the communications node, the received PPDU to obtain a duration field, and update a current NAV value of the communications node according to a value of the duration field.

A specific method for updating the current NAV value of the receiving node according to the value of the duration field may be: determining whether the value of the duration field is greater than the current NAV, and updating the current NAV if the value of the duration field is greater than the current NAV, or skipping updating the current NAV if the value of the duration field is not greater than the current NAV; or setting the NAV value of the node by using the value of the duration field; or another specified updating method.

In Embodiment <NUM> of the present application, the processor <NUM> may be configured to execute step S12 to step S14, and the memory <NUM> is configured to store a program and data that are required for the processor <NUM> to execute the foregoing steps.

In Embodiment <NUM>, which is not according to the claims, when a current NAV value of a station is set according to an <NUM>. 11ax PPDU sent by a node (an access point or a station) in an intra basic service set (intra-BSS), after receiving a trigger frame including uplink scheduling information of the station, the station does not consider the current NAV value as a condition for determining whether to send an uplink data frame. 11ax PPDU sent by the node in the intra-BSS includes: a trigger frame, a downlink data frame, an acknowledgement frame (such as ACK/BA), a request frame, or a response frame sent by the access point, or an uplink data frame, an acknowledgement frame (such as ACK/BA), a response frame, or a request frame sent by the station, or the like.

Alternatively, when a current NAV value of a station is set according to an <NUM>. 11ax PPDU sent by a node in an intra-BSS, and the station does not receive a request frame/response frame (including a case in which no RTS/CTS is exchanged between the station and another node, or a case in which the station does not receive RTS/CTS due to transmission), after receiving a trigger frame including uplink scheduling information of the station, the station does not consider the current NAV value when determining whether to send an uplink data frame. 11ax PPDU sent by the node in the intra-BSS includes: a trigger frame, a downlink data frame, or an acknowledgement frame (such as ACK/BA) sent by an access point, or an uplink data frame or an acknowledgement frame (such as ACK/BA) sent by a station.

The request frame may be RTS (request to send) in an existing format, a multi-user request to send frame MU-RTS, an enhanced request to send frame e-RTS, a simultaneous request to send frame simultaneous RTS, or the like.

The response frame may be CTS (request to send) frame in an existing format, a multi-user clear to send frame MU-CTS, an enhanced clear to send frame e-CTS, a simultaneous clear to send frame simultaneous CTS, or the like.

Not considering the current NAV value may be specifically: skipping determining the NAV value, setting the NAV value to zero, or the like.

Optionally, the condition for determining whether to send an uplink data frame may further include: performing clear channel assessment (CCA) on a current channel by using a CCA threshold (for example, an OBSS PD level value). When the clear channel assessment is busy, an uplink data frame is not sent.

As shown in <FIG>, a NAV is set for a STA <NUM> according to a trigger frame sent by an AP in an intra-BSS. When the AP sends a trigger frame to the STA <NUM> to perform uplink scheduling, the STA <NUM> may not consider the NAV when sending a UL MU PPDU.

As shown in <FIG>, a STA <NUM> does not correctly receive the first trigger frame sent by an AP in an intra-BSS, but correctly receives a UL MU PDDU sent by a nearby STA <NUM>, and sets the NAV accordingly. When the AP sends a trigger frame to the STA <NUM> to perform uplink scheduling, the STA <NUM> may not consider the NAV when sending a UL MU PPDU.

In Embodiment <NUM>, which is not according to the claims, when a station already responds with a response frame (for example, CTS, MU-CTS, e-CTS, or simultaneous CTS) after receiving a request frame, after receiving a trigger frame including uplink scheduling information of the station, the station does not consider a current NAV value as a condition for determining whether to send an uplink data frame.

A specific method for not considering the current NAV value may be: skipping determining the NAV value, setting the NAV value to zero, or the like.

In Embodiment <NUM>, which is not according to the claims, when a station does not respond with a response frame (for example, CTS, MU-CTS, e-CTS, or simultaneous CTS), after receiving a trigger frame including uplink scheduling information of the station, the station considers a current NAV value as a condition for determining whether to send an uplink data frame (for example, if the current value is not zero, the station does not perform channel contention or transmission). That the station does not respond with a response frame may be that because the station does not receive a request frame, the station does not respond with a response frame, or that the station receives a request frame, but does not respond with a response frame.

In Embodiment <NUM> of the present application, when a station does not respond with a response frame (for example, CTS, MU-CTS, e-CTS, or simultaneous CTS), after receiving a trigger frame including uplink scheduling information of the station, the station considers a current NAV value as a condition for determining whether to send an uplink data frame. That the station does not respond with a response frame may be that the station receives RTS, but does not respond with CTS.

In Embodiment <NUM>, which is not according to the claims, when a current NAV value of a station is set according to an <NUM>. 11ax PPDU sent by a node (an access point or a station) in an intra basic service set (intra-BSS), and the station responds with a response frame (for example, CTS, MU-CTS, e-CTS, or simultaneous CTS), after receiving a trigger frame including uplink scheduling information of the station, the station does not consider the current NAV value as a condition for determining whether to send an uplink data frame. 11ax PPDU sent by the node in the intra-BSS includes: a trigger frame, a downlink data frame, or an acknowledgement frame (such as ACK/BA) sent by an access point, or an uplink data frame sent by a station.

Optionally, the condition for determining whether to send an uplink data frame may include: performing clear channel assessment (CCA) on a current channel by using a CCA threshold (for example, an OBSS PD level value). When the clear channel assessment is busy, an uplink data frame is not sent.

As shown in <FIG>, a NAV of a STA <NUM> is set according to the first trigger frame (there is no uplink scheduling of the STA <NUM>) sent by an AP in an intra-BSS. If the STA <NUM> already responds with simultaneous CTS, when receiving a trigger frame for uplink scheduling of the STA <NUM> in a transmission opportunity (TXOP), the STA <NUM> may not consider the NAV when sending a UL MU PPDU.

In Embodiment <NUM>, which is not according to the claims, when a current NAV value of a station is set according to an <NUM>. 11ax PPDU sent by a node (an access point or a station) in an intra basic service set (intra-BSS), and the station does not respond with a response frame (for example, CTS, MU-CTS, e-CTS, or simultaneous CTS), after receiving a trigger frame including uplink scheduling information of the station, the station considers the current NAV value as a condition for determining whether to send an uplink data frame (for example, if the current NAV value is not zero, the station does not perform channel contention or transmission). 11ax PPDU sent by the node in the intra-BSS includes: a trigger frame, a downlink data frame, or an acknowledgement frame (such as ACK/BA) sent by the access point, or an uplink data frame sent by the station.

As shown in <FIG>, a NAV of a STA <NUM> is set according to the first trigger frame (there is no uplink scheduling of the STA <NUM>) sent by an AP in an intra-BSS. If the STA <NUM> does not respond with simultaneous CTS, when receiving a trigger frame for uplink scheduling of the STA <NUM> in a TXOP, the STA <NUM> needs to consider a NAV when sending a UL MU PPDU.

In Embodiment <NUM> of the present application, when a current NAV value of a station is set according to an <NUM>. 11ax PPDU sent by a node (an access point or a station) in an intra basic service set (intra-BSS), and the station does not respond with a response frame CTS (for example, CTS, MU-CTS, e-CTS, or simultaneous CTS), after the station receives a trigger frame including uplink scheduling information of the station, the station considers the current NAV value as a condition for determining whether to send an uplink data frame. That the station does not respond with a response frame may be that the station receives RTS, but does not respond with CTS.

With reference to Embodiment <NUM> to Embodiment <NUM>, Embodiment <NUM>, which is not according to the claims, discloses a communication method in a wireless communications system.

The condition of not considering a NAV includes that a current NAV value of the station is set according to the <NUM>. 11ax PPDU sent by the node (the access point or the station) in the intra basic service set. Alternatively, the condition of not considering a NAV includes that a current NAV value of the station is set according to the <NUM>. 11ax PPDU sent by the node (the access point or the station) in the intra basic service set, and that the station does not receive a request frame or a response frame (another node does not send a request frame or a response frame to the station, or the station does not receive a request frame or a response frame due to transmission). Alternatively, the condition of not considering a NAV includes that the station already responds with a response frame after receiving a request frame. Alternatively, the condition of not considering a NAV includes that a current NAV value of the station is set according to the <NUM>. 11ax PPDU sent by the node (the access point or the station) in the intra basic service set, and that the station already responds with a response frame after receiving a request frame.

S23: If the condition of not considering a NAV is not satisfied, after receiving the trigger frame including the uplink scheduling information of the station, the station considers the NAV when determining whether to send an uplink data frame. For example, when a current NAV value is not zero, the station does not perform channel contention or transmission.

It may be clearly understood by a person skilled in the art that, for the purpose of convenient and brief description, for a detailed working process of the foregoing system, apparatus, and unit, reference may be made to a corresponding process in the foregoing method embodiments, and details are not described.

When the functions are implemented in the form of a software functional unit and sold or used as an independent product, the functions may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of the present invention essentially, or the part contributing to the prior art, or a part of the technical solutions may be implemented in a form of a software product. The software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device) or a processor to perform all or a part of the steps of the methods described in the embodiments of the present invention. The foregoing storage medium includes: any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc.

Claim 1:
A computer program including instructions, which, when carried out by a computer, cause the computer to perform a NAV setting method , wherein the method comprises:
receiving (S01) a PPDU from a transmitting node, wherein the PPDU is from an OBSS;
determining (S02) whether the computer satisfies a condition of allowing simultaneous transmission;
if the condition of allowing simultaneous transmission is satisfied, keeping (S03) a current NAV value unchanged; or
if the condition of allowing simultaneous transmission is not satisfied, decoding (S04) the received PPDU to obtain a duration field, and determining whether the value of the duration field is greater than the current NAV, and
updating the current NAV if the value of the duration field is greater than the current NAV, or
skipping updating the current NAV if the value of the duration field is not greater than the current NAV.