CN106941731A

CN106941731A - NAV methods to set up and relevant device in wireless communication system

Info

Publication number: CN106941731A
Application number: CN201610006493.9A
Authority: CN
Inventors: 庞继勇; 向铮铮
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2016-01-04
Filing date: 2016-01-04
Publication date: 2017-07-11
Anticipated expiration: 2036-01-04
Also published as: CN106941731B

Abstract

The invention provides NAV methods to set up and its relevant device in a kind of wireless communication system, STA or AP receives the 2nd PPDU, wherein, 2nd PPDU and the first PPDU comes from same OBSS, wherein, first PPDU is to be received before the 2nd PPDU by the STA or AP, wherein, the STA or AP current NAV is updated based on the first PPDU；If the STA or AP meets the condition of concurrent transmission that allows, the STA or AP ignore the current NAV, carry out concurrent transmission.

Description

NAV setting method and related equipment in wireless communication system

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a NAV setting method and related apparatus in a wireless communication system.

Background

With the development of the mobile internet and the popularization of the intelligent terminal, the data traffic shows a explosive growth trend. Wireless Local Area Network (WLAN) is one of the mainstream mobile broadband access technologies today due to its advantages of high speed and low cost.

In a WLAN based on an 802.11 protocol (such as mainstream 802.11a/g/n/ac) established by the Institute of Electrical and Electronics Engineers (IEEE), multiple Basic Service Sets (BSSs) may be included, and each BSS may include a Station of an Access Point (AP) and one or more stations of a Non-Access Point class (Non-AP STA) associated with the AP, where the Non-AP STA is referred to as STA for short as follows.

In a WLAN based on an 802.11 protocol, a Distributed Coordination Function (DCF) is mainly used as an access control method of wireless medium resources. In the DCF mode, the wireless medium, i.e., the wireless channel, is occupied by a contention mechanism based on Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA). Before sending data, the STA or AP first monitors the channel state, performs random backoff if the channel is continuously idle for a period of time, and can actually start data transmission if the backoff ends and the channel is still idle.

Carrier Sensing used in the DCF for determining a busy/idle state of a channel is classified into two modes, Physical Carrier Sensing (PCS) and Virtual Carrier Sensing (VCS). The result of PCS is represented by Clear Channel Assessment (CCA) provided by the physical layer, and CCA generally determines the busy-idle state of the current channel based on a Signal Detection (SD) or Packet Detection (PD) threshold and/or an Energy Detection (Energy Detection) threshold. When the CCA result is higher than a given threshold, the channel status is considered to be busy, and otherwise, the channel status is idle. It is worth noting that for SD or PD based CCA, a STA or AP may treat signals from a local BSS and an Overlapping BSS (OBSS) separately by setting different CCA thresholds so as to be "inside tight" and outside loose ". Generally, a MAC frame is encapsulated into a PPDU in a physical layer by adding a physical header or a preamble, and an STA or an AP may determine whether a received PPDU is from a local BSS or an OBSS through address information in a frame header of a Media Access Control (MAC) frame or a BSS identifier (e.g., a BSScolor identifier in HE-SIG-a) in a header or a signaling field of a Physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU) carrying the MAC frame.

The VCS completes the operation by setting a Network Allocation Vector (NAV) in a Duration field in a header of the MAC frame, where a start time of the Duration field is a PPDU transmission end time carrying the Duration information. The NAV may be understood as a Timer counter indicating how long the channel is still occupied, with each listening STA or AP maintaining a NAV counter (software or hardware implementation). The value of NAV decreases over time, and the STA or AP always considers the wireless channel busy and stops channel contention and data transmission until the NAV value decreases to zero (even if the CCA result is idle).

A transmitting station (including STA or AP) and/or a receiving station (including STA or AP) of a communication link may broadcast its reserved channel usage time or the remaining time of a current transmission Opportunity (TXOP) to a neighbor STA or AP by setting a Duration field in a header of a MAC frame transmitted by it. Generally, the destination receiving station (including STA or AP) of the PPDU does not need to update its own NAV counter according to the Duration information in the PPDU. Meanwhile, other stations (including STA or AP) around the communication link need to determine whether to update their own NAV counters according to the size of the Duration field in the received MAC frame, and when the received Duration value is greater than the current remaining count value of their own NAV counters, set the NAV count value to the count value indicated by the newly received Duration field after the end of the received PPDU transmission. Specifically, in the current 802.11ax standard discussion, a TXOP field is included in a signaling symbol in a header (also referred to as a preamble) of a PPDU to indicate a remaining transmission time in the current TXOP. The effect is equivalent to placing a Duration field in the physical layer. That is, the STA or the AP may notify or update the NAV counter of the STA or the AP to a neighbor STA or the AP through TXOP in physical header signaling of the transmitted PPDU and/or Duration information in a header of a MAC frame carried. It is understood that the TXOP field in the PPDU physical header signaling and the Duration field in the MAC frame header are collectively referred to as the NAV Duration.

It is apparent that the above-described prior rules for NAV setting and updating effectively guarantee the uniqueness of channel usage in neighboring areas, avoiding mutual interference and collisions between transmission links. But this also limits the number of concurrent links in the neighborhood, making network area throughput difficult to further increase. The next generation 802.11 protocol 802.11ax introduces spatial multiplexing technique to improve the WLAN resource utilization efficiency. The STA or the AP may increase the CCA threshold, so that the original link that cannot concurrently transmit may perform spatial concurrent transmission, thereby increasing the network throughput. However, under the trend that WLAN deployments are more and more intensive, if the current NAV update rule is continuously followed, the advantage of intensive deployment cannot be exerted, and the increasing service requirements cannot be met.

Disclosure of Invention

The embodiment of the invention provides a NAV setting method and related equipment in a wireless communication system, which can improve the system throughput.

A first aspect of the present invention provides a NAV setting method in a wireless communication system, the method comprising: the STA or the AP receives the second PPDU; the second PPDU and the first PPDU are from the same OBSS, wherein the first PPDU is received by the STA or the AP before the second PPDU; wherein the current NAV of the STA or the AP is updated based on the first PPDU; if the STA or the AP meets the condition of allowing concurrent transmission, the STA or the AP ignores the current NAV and performs concurrent transmission.

A second aspect of the present invention provides a STA or AP, comprising: a receiver configured to receive a second PPDU, wherein the second PPDU and a first PPDU are from a same OBSS, wherein the first PPDU is received by the STA or the AP before the second PPDU; wherein the current NAV of the STA or the AP is updated based on the first PPDU; and the processor is used for ignoring the current NAV and carrying out concurrent transmission by the STA or the AP if the STA or the AP meets the condition of allowing concurrent transmission.

The invention mainly designs a NAV mechanism under concurrent transmission, which can increase the spatial multiplexing capability of the system and improve the throughput of the whole network.

Drawings

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

Fig. 1 is a schematic diagram of a communication system suitable for use in accordance with an embodiment of the present invention.

Fig. 2 is a flowchart illustrating a NAV setting method in a wireless communication system according to an embodiment of the present invention.

Fig. 3-5 are diagrams illustrating different frame structures of PPDUs of 802.11ax format according to an embodiment of the present invention.

Fig. 6-10 are timing diagrams of NAV according to embodiments of the present invention.

Fig. 11 is a composition diagram of a communication node in the second embodiment of the present invention.

Detailed Description

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

The embodiment of the invention can be applied to a WLAN, wherein the WLAN can comprise a plurality of BSSs, and the BSSs can comprise an AP and one or more STAs associated with the AP.

An AP, also referred to as a wireless access point or hotspot, etc. The AP is an access point for a mobile subscriber to enter a wired network, and is mainly deployed in a home, a building, and a campus, and typically has a coverage radius of several tens of meters to hundreds of meters, and may be deployed outdoors. The AP acts as a bridge connecting the network and the wireless network, and mainly functions to connect the wireless network clients together and then to access the wireless network to the ethernet.

The STA can be a wireless communication chip, a wireless sensor or a wireless communication terminal. For example: the mobile phone supporting the WiFi communication function, the tablet computer supporting the WiFi communication function, the set top box supporting the WiFi communication function, the smart television supporting the WiFi communication function, the smart wearable device supporting the WiFi communication function and the computer supporting the WiFi communication function.

Currently, the standard mainly adopted by the STA or the AP is the IEEE 802.11 series. Specifically, the STA or the AP may be a device with a WiFi (Wireless Fidelity) chip. Optionally, the STA or the AP may be a device supporting 802.11ax standard, and further optionally, the STA or the AP may be a device supporting multiple WLAN standards such as 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11 a.

With the development of communication technology, in order to improve the system throughput in a dense scene, a Spatial Reuse (SR) concept is introduced, and two or more communication links are allowed to use the same time-frequency resource (i.e., use the same channel in the same time period) for transmission in a certain scene or condition. Specifically, it can be understood that: when a STA or AP in a local BSS senses a PPDU from an OBSS on a current channel, even if the signal strength of the PPDU is higher than-82 dBm but is lower than an OBSS PD threshold or an OBSS CCA threshold or an SR CCA threshold, generally, the OBSS PD threshold may satisfy-82 dBm < OBSS PD threshold < -62dBm, and the STA or AP in the local BSS may multiplex the same channel for spatial multiplexing link transmission by some means (e.g., adjusting transmission power) under certain conditions (e.g., without affecting currently ongoing OBSS communication). For example, as shown in fig. 1, while AP1 transmits downlink data to STA1 (the link between AP1 and STA1 may be referred to as a primary link), STA2 may use all or part of the time-frequency resources of the primary link for uplink data transmission with AP2 (the link between AP2 and STA2 may be referred to as a spatial multiplexing link). The original link and the spatial multiplexing link are relative concepts, and the original link and the spatial multiplexing link have intersection on transmission time or the transmission time of the spatial multiplexing link is a subset of the transmission time of the original link. For another link B starting during the transmission period of the link a, if the transmitting end STA or AP of the link B is within the effective communication distance of the transmitting end STA or AP or/and the receiving end STA or AP of the link a, and the link B uses all or part of the time-frequency resources of the link a, it may be called that the link a is the original link of the link B; correspondingly, link B is a spatially multiplexed link with respect to link a. In general, the primary link may be an uplink transmission link (i.e., transmission from the STA to the AP) or a downlink transmission link (i.e., transmission from the AP to the STA), and fig. 1 shows a case of downlink transmission of the primary link. The spatial multiplexing link may also be uplink transmission or downlink transmission, fig. 1 illustrates the uplink transmission as an example, and the spatial multiplexing link is generally located in a different BSS from the original link. Generally, PPDUs of different BSSs will carry different BSS identities, which may be BSS colors located in a PPDU preamble signaling domain, or BSS identifiers BSSIDs located in an address domain in a header of a MAC frame carried in the PPDU, or other representations.

To enable spatial multiplexing/concurrent transmission, the current 802.11ax standard discussion has agreed that when certain concurrency conditions are met, the NAV information in the OBSS PPDU can be ignored to enable concurrent transmission. The detailed discussion describes the following two sections of text:

1) when the Received Signal Strength Indication (RSSI) of the OBSS PPDU is lower than the currently used OBSS PD threshold of the STA or the AP, and some pending conditions are met, the STA or the AP may consider that the OBSS PPDU has not been Received at all, so that it is not necessary to update its own NAV counter according to the NAV Duration information in the OBSS PPDU. This relaxes the NAV setting and updating rules compared to the 11ax prior standard, allowing the STA or AP more opportunity to multiplex the channel being used by the OBSS.

English can be:

A STA should regard an Inter-BSS PPDU with a valid PHY header and thathas a receive power/RSSI below the OBSS PD level used by the receiving STAand that meets additional TBD conditions,as not having been received at all(e.g.,should not update its NAV),except that the medium condition shall indicateBUSY during the period of time that is taken by the receiving STA to validatethat the PPDU is from an Inter-BSS,but not longer than the time indicated as thelength of the PPDU payload.The OBSS PD level is greater than the minimumreceive sensitivity level.

2) on the basis of 1), it is further noted that the STA or AP may raise the OBSS PD threshold used by lowering the transmit power. That is, if the STA or AP has the ability to transmit at a lower power, it may use a higher OBSS PD threshold to determine the OBSS PPDU. Therefore, the STA or the AP may ignore the OBSS PPDU with the higher RSSI, increase the probability that the channel is determined to be spatial, and improve the spatial multiplexing concurrency opportunity.

English can be:

An 11ax STA regards a valid OBSS PPDU as not having been received at all(e.g.,should not update its NAV),except that the medium condition shall indicateBUSY during the period of time that is taken by the receiving STA to validatethat the PPDU is from an Inter-BSS,but not longer than the time indicated as thelength of the PPDU payload if the RXPWR of the received PPDU is below theOBSS_PD threshold and TBD conditions are met,noting that the OBSS_PDthreshold is accompanied by a TXPWR value and a reduction in the TXPWRmay be accompanied by an TBD increase in the OBSS_PD threshold value.

it has been mentioned above that the start time of the validity period of the NAV Duration information (whether the TXOP field in the physical header signaling field or the Duration field in the header of the MAC frame) contained in a PPDU is the end time of the PPDU transmission. Thus, as shown in fig. 6, although a receiving STA or AP may ignore NAV1 of an OBSS PPDU1 (where PPDU1 may be regarded as a second PPDU, and the following description is similarly understood and will not be repeated), if the NAV0 count value of the receiving STA or AP before receiving the OBSS PPDU1 (time T0) is not 0, and if the NAV0 is not reduced to 0 yet when the receiving STA or AP determines that the PPDU1 is the same OBSS PPDU (a certain time between T0 and T1), the STA or AP may wait until NAV0 is reduced to 0 (time T2) to start channel contention for concurrent transmission. In particular, if the NAV0 has not yet decreased to 0 at the OBSS PPDU1 transmission end time (T1 time), the STA or AP may still not initiate concurrent transmission although the NAV1 information of the OBSS PPDU1 has been ignored.

In fact, if the NAV0 is set/updated by the PPDU0 from the same OBSS (the PPDU0 may be regarded as the first PPDU, and the following description is similar to and understood and is not repeated), the STA or the AP may not start concurrent transmission until the NAV0 is reduced to 0, but may start concurrent transmission after determining that the PPDU1 is from the same OBSS. This is possible because both PPDU0 and PPDU1 in tandem are from the same OBSS, and the STA or AP must be able to match the latest/current transmission state of the OBSS based on the concurrent decisions and decisions made by PPDU 1. Then if the STA or AP initiates concurrent transmissions during the transmission of PPDU1 and/or within its NAV1 validity period (assuming certain concurrency conditions are met), it does not impact communications during the transmission of PPDU0 (in fact PPDU0 has already been transmitted before PPDU 1) and/or during the overlap of its NAV0 validity period with the NAV1 validity period.

In short, in the above case, the STA or the AP cannot start the concurrent transmission earlier, and cannot utilize the opportunity of the channel concurrent transmission to the maximum extent.

Therefore, how to make a potential concurrent STA or AP start concurrent transmission as early as possible when determining that the spatial multiplexing concurrency condition is satisfied, in the case that the current NAV is non-zero? Through the modification of the NAV rule, the potential concurrent STA or AP can ignore the NAV information in the current PPDU and the set NAV count value under some special conditions, initiate concurrent transmission as early as possible, and improve the efficiency of spatial multiplexing.

The first embodiment is as follows:

referring to fig. 1, an embodiment of the present invention provides a NAV setting method in a wireless communication system, including the following steps:

s01: receiving, by an STA or an AP, a second PPDU, wherein the second PPDU and a first PPDU are from a same OBSS, wherein the first PPDU is received by the STA or the AP before the second PPDU, and wherein a current NAV of the STA or the AP is updated based on the first PPDU;

s02: if the STA or the AP meets the condition of allowing concurrent transmission, the STA or the AP ignores the current NAV and performs concurrent transmission.

Of course, the STA or AP will store the BSS identity carried in the OBSS PPDU that is used to trigger setting or updating the NAV, such as the BSS color in the PPDU physical preamble signaling field or the BSS ID in the MAC frame address field (the BSS ID may be carried in the transmit address or receive address field in the MAC address field). By comparing the BSS identities, it is determined whether the latest received PPDU is from the same OBSS as the PPDU used to trigger the last set/update NAV. These actions may be supplemented as actions of the STA or the AP, although not described in S01 or S02.

Optionally, ignoring the current NAV may be implemented in one of the following ways:

the first method is as follows:

if the end time of the current NAV is earlier than or equal to the end time of the TXOP corresponding to the second PPDU or the carried NAV Duration, ignoring the current NAV;

the above earlier than or equal to case can be seen in the examples shown in fig. 6-8. The end time of the NAV0 is shown in fig. 6 to be later than the start time of the NAV1 and earlier than the end time of the NAV1, the end time of the NAV0 is shown in fig. 7 to be before the start time of the NAV1, and the end time of the NAV0 is shown in fig. 8 to be the same as the end time of the NAV 1.

In general, and without limitation to the examples of fig. 6-8, a STA or AP receives a PPDU0 from an OBSS0 before time T0 and updates its NAV count value based on NAV information NAV0 in the PPDU 0. If the STA or AP receives the PPDU1 at time T0 and detects that the PPDU1 is from the OBSS1 at a time T2' before the transmission end time T1 of the PPDU1, the STA or AP may ignore the NAV information NAV1 included in the PPDU1 (without updating its NAV according to the NAV 1) if the concurrent transmission is satisfied. On this basis, if OBSS0 is the same OBSS as OBSS1 and the end time of NAV0 is after T2 ', the STA or AP may further ignore the NAV0 count between time T2' and the expiration of NAV1 validity period. Then, the STA or AP may initiate concurrent transmission at or after time T2 ' and at some time before the NAV0 count decrements to 0 (if NAV0 has decremented to 0 before T2 ', then without the invention, the STA or AP may initiate concurrent transmission after T2 ' as per the rules of the existing standards) without waiting for the T2 time to initiate concurrent transmission.

The second method comprises the following steps:

and if the end time of the current NAV is later than or equal to the end time of the TXOP corresponding to the second PPDU or the end time of the carried NAV Duration, ignoring the current NAV until the end time of the TXOP corresponding to the second PPDU or the end time of the carried NAV Duration.

As shown in fig. 9, the end time of NAV0 is after the end time of NAV 1.

In the following, with reference to fig. 10, for more intuition, PPDU0 and PPDU1 in the first embodiment are embodied as Trigger frames (Trigger frames, referred to as TFs) introduced in 802.11ax, that is, PPDU0 is TF0, and PPDU1 is TF 1. The workflow of NAV updating and concurrent transmission is presented as may be applicable to STAs or APs as in fig. 6-9, although fig. 10 depicts exemplary NAVs 0 and 1 and NAV 0' and the end times of the NAVs simply drawn as the same end times.

STA0 in the local BSS first listens to a trigger frame TF0 (for scheduling uplink transmission of OBSS STA1, where STA1 may refer to one STA or a group of STAs) from the OBSS AP, and assuming that RSSI of TF0 reaching STA0 is not less than the OBSS PD threshold used by STA0, or STA0 cannot meet the condition (if any) for allowing concurrent transmission carried in TF0, STA0 updates its NAV according to NAV information NAV0 carried in TF0 (assuming that NAV0 carried in TF0 is greater than NAV of STA 0), and the end time of the NAV of updated STA0 is T2. Meanwhile, the STA0 records the information of which OBSS the PPDU triggering this NAV update is from under the reservation.

According to the existing rule, the OBSS STA1 transmits uplink data (ul PPDU _1) according to the scheduling indication in the TF0 while setting NAV information NAV 0' in PPDU _1 to a time length from the end time of PPDU _1 to the time T2. If STA0 receives PPDU _1, it does not need to update its NAV based on the NAV information carried in PPDU _1 because the NAV 0' value in PPDU _1 is not greater than the NAV of STA0 at the same time.

After the PPDU _1 transmission is finished, the OBSS AP sends another trigger frame TF1 in the current TXOP again, and assuming that RSSI of TF1 received by STA0 is smaller than an OBSS PD threshold used by STA0 (for example, the OBSS AP reduces power for sending TF 1), or STA0 may satisfy conditions for allowing concurrent transmission carried in TF1 (if any, conditions for allowing concurrent transmission carried by TF0 and TF1 may be different because uplink users may be scheduled differently), STA0 may regard as not receiving TF1 according to the latest 11ax standard, and thus it is not necessary to deal with NAV information NAV1 carried in TF 1. But since the NAV of STA0 was not 0 until time T2, STA0 cannot initiate concurrent transmissions until time T2.

In fact, if STA0 initiates a concurrent transmission after determining that TF1 is from the OBSS or that the spatial multiplexing condition is satisfied (time T2'), it is not possible to interfere with the transmission in the OBSS (e.g., PPDU _ 2). According to the method in the first embodiment, when STA0 determines that its NAV is updated from the same OBSS as TF1, STA0 may ignore its NAV from time T2' until the end of NAV1 (in fig. 10, the end of NAV1 is exactly the same as the end of NAV 0). STA0 may then initiate a spatial multiplexing concurrent transmission at a time (e.g., T2') that is some time prior to time T2.

Optionally, before performing the concurrent transmission, the STA or the AP further includes: the STA or AP performs channel contention to obtain a transmission opportunity for concurrent transmission.

Optionally, the condition for allowing concurrent transmission includes: if the current CCA threshold of the STA or the AP is set to be larger than a certain preset value, when the RSSI of the second PPDU detected by the STA or the AP to be received is smaller than or equal to the current CCA threshold of the STA or the AP or the increased CCA threshold; or the STA or the AP is in a CCA idle (CCA idle) state, or a concurrent transmission link potentially established by the STA or the AP is a near point communication link, or the received second PPDU indicates that concurrent transmission is allowed, or a combination of more than one of them.

Alternatively, for a transmission link (whether uplink or downlink transmission) between a STA and an AP in a local BSS to which the STA belongs, the transmission link between the AP and the STA may be referred to as a near point communication link if one or a combination of the following conditions is satisfied:

the distance between the STA and the AP is smaller than or equal to a preset threshold value;

or,

the RSSI of the PPDU sent by the AP and received by the STA is greater than or equal to a preset RSSI critical value;

or,

the RSSI of the PPDU sent by the STA and received by the AP is greater than or equal to a preset RSSI critical value.

Optionally, the indicating, in the received second PPDU, that the concurrent transmission is allowed specifically includes:

in the PPDU of 802.11ax format, SR allowed flag indication information of 1 bit can be added in HE-SIG-A or HE-SIG-B or MAC frame header part to indicate whether to allow concurrent transmission; and/or; in the Legacy PPDU, SR allowed flag indication information of 1 bit may be added to a frame header of the MAC frame to indicate whether concurrent transmission is allowed.

The following may be understood in particular:

in a PPDU (including a data Frame, a control Frame such as an RTS or CTS or a Trigger Frame, or a management Frame) in an 802.11ax format, an SR allowed flag of 1 bit or an SR allowed flag of n (n is an integer greater than 1) bits may be added to a common part or a MAC Frame header of an HE-SIG-a or an HE-SIG-B, or a special value (e.g., all zeros or other special value) of an added field (SRfield) for concurrent transmission (e.g., an Interference threshold level or an Interference tolerance margin) to indicate whether to allow concurrent transmission; and/or

In a Legacy PPDU (e.g., a control frame such as RTS, CTS, or Trigger frame, or a management frame), an SR allowed flag of 1 bit or an SR allowed flag of n (n is an integer greater than 1) bits may be added to a header of a MAC frame, or a special value (e.g., all zeros or other special value) of an added field (SR field) for concurrent transmission (e.g., an Interference threshold level or an Interference tolerance margin) indicates whether concurrent transmission is allowed;

the specific position of SR allowed flag in PPDU can be seen in FIGS. 2-4.

Optionally, the PPDU in 802.11ax format includes a data frame, a control frame such as RTS or CTS or TriggerFrame, or a management frame; the Legacy PPDU includes a control frame such as an RTS, CTS, or Trigger frame, or a management frame.

Further optionally, the CCA threshold may be one or a combination of more than one of a Preamble Detection (Preamble Detection) threshold, a Signal Detection (Signal Detection) threshold, a Packet Detection (Packet Detection) threshold, an Energy Detection (Energy Detection) threshold, or a WiFi Signal Detection threshold.

Further optionally, the preset value may be a minimum or preset preamble detection or signal detection or packet detection threshold value; or may be a preset or minimum energy detection threshold; a WiFi signal detection threshold value that may be preset or minimum; other preset threshold values are also possible.

The following may be understood in particular:

the preset value may be a preset or minimum preamble detection/signal detection/packet detection threshold (e.g., -82dBm default in a 20MHz system bandwidth, or-79 dBm in a 40MHz system bandwidth), and specifically may be a threshold adopted in the case of solving the preamble of the signal; or a preset or minimum energy detection threshold (e.g., -62dBm as a default in a 20MHz system bandwidth), which may specifically be a threshold adopted in a case where a signal cannot be solved or a signal preamble cannot be solved; the detection threshold may be a preset or minimum WiFi signal detection threshold (e.g., -72dBm default in a 20MHz system bandwidth), and specifically may be a threshold that is adopted when a signal preamble cannot be solved but a WiFi or 802.11ax signal can be determined; other preset threshold values are also possible.

Optionally, the method for determining whether the received PPDU is from an OBSS includes: and judging whether the received PPDU comes from the OBSS according to the BSS color field in the HE-SIG-A, or judging whether the received PPDU comes from the OBSS according to the Receiving Address (RA) or the sending address (TA) of the MAC header.

Optionally, the first PPDU and the second PPDU are from OBSSs of the STA or the AP in the WLAN.

The current NAV may be set by the STA or the AP for PPDUs from all OBSSs of the local BSS and the STA or the AP, may be set for PPDUs from all OBSSs of the STA or the AP, or may be set for PPDU from one OBSS or a group of OBSSs of the STA or the AP.

Example two

Referring to fig. 5, an embodiment of the present invention further provides a STA or AP 100, which includes a receiver 101 and a processor 103. Optionally including a transmitter 102. Further optionally, a memory 104 is included. Further optionally, a bus may be included.

A receiver configured to receive a second PPDU, wherein the second PPDU is from a same OBSS as a first PPDU, wherein the first PPDU is received by a communication node before the second PPDU; wherein the current NAV of the communication node is updated based on the first PPDU; and

a processor configured to ignore the current NAV and perform a concurrent transmission if the communication node satisfies a condition for allowing the concurrent transmission.

Optionally, the processor is specifically configured to ignore the current NAV according to one of the following ways:

if the end time of the current NAV is earlier than or equal to the end time of the TXOP corresponding to the second PPDU or the end time of the carried NAV Duration, ignoring the current NAV;

Optionally, the condition for allowing concurrent transmission includes: if the current CCA threshold of the communication node is set to be greater than a certain preset value, when the communication node detects that the RSSI of the second PPDU received by the communication node is less than or equal to the current CCA threshold of the communication node or the increased CCA threshold; or the communication node is in a CCA idle (CCA idle) state, or a concurrent transmission link potentially established by the communication node is a near point communication link, or the received second PPDU indicates that concurrent transmission is allowed, or the like.

Optionally, the first PPDU and the second PPDU are from OBSSs of the communication node in the WLAN.

The communication node is an AP or STA.

The current NAV may be set by the communication node for PPDUs from all OBSSs of the local BSS and the communication node, may be set only for PPDUs from all OBSSs of the communication node, or may be set only for PPDU from one or a group of OBSSs of the communication node.

The description of the above method embodiment may be applied to the communication node embodiment, and is not described herein again.

In an embodiment of the present invention, the processor 103 is configured to execute the step S02, and the memory 104 is configured to store the program and data required by the processor 103 to execute the step.

In the above embodiments, the symbol/represents or, and a and/or B represents three cases: a, B, A and B.

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

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

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

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

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

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

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention, and therefore, the scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for NAV setting in a wireless communication system, the method comprising:

the STA or the AP receives a second Physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU);

the second PPDU and a first PPDU are from a same Overlapping Basic Service Set (OBSS), wherein the first PPDU is received by the STA or the AP before the second PPDU; wherein a current Network Allocation Vector (NAV) of the STA or AP is updated based on the first PPDU;

and if the STA or the AP meets the condition of allowing the concurrent transmission, the STA or the AP ignores the current NAV and performs the concurrent transmission.

2. The method of claim 1, wherein ignoring the current NAV is performed in one of:

ignoring the current NAV if the ending time of the current NAV is earlier than or equal to the ending time of a transmission Opportunity (TXOP) corresponding to the second PPDU or the ending time of a carried NAVDuration;

and if the ending time of the current NAV is later than or equal to the ending time of the TXOP corresponding to the second PPDU or the ending time of the carried NAV Duration, ignoring the current NAV until the ending time of the TXOP corresponding to the second PPDU or the ending time of the carried NAV Duration.

3. The method of claim 1 or 2, wherein the STA or AP, prior to performing the concurrent transmission, further comprises:

the STA or AP performs channel contention to obtain a transmission opportunity for concurrent transmission.

4. The method according to any of the preceding claims, wherein the conditions allowing concurrent transmission comprise: if a CCA threshold of a current channel Clear assessment (STA) of the STA or the AP is set to be greater than a preset value, when the STA or the AP detects that an RSSI (Received Signal Strength Indication) of the second PPDU Received is less than or equal to the CCA threshold of the STA or the AP currently or after the CCA threshold is increased; or the STA or the AP is in a CCA idle (CCA idle) state, or a concurrent transmission link potentially established by the STA or the AP is a near point communication link, or a received second PPDU indicates that concurrent transmission is allowed, or the like.

5. The method of any of the preceding claims, wherein the first PPDU and the second PPDU are from OBSSs of the STA or AP in the WLAN.

6. The method according to any of the preceding claims,

the current NAV may be set by the STA or the AP for PPDUs from a local BSS and all OBSSs of the STA or the AP, may be set for PPDUs from all OBSSs of the STA or the AP, or may be set for PPDU from one or a group of OBSSs of the STA or the AP.

7. A communication node, comprising:

a receiver configured to receive a second PPDU, wherein the second PPDU is from a same OBSS as a first PPDU, wherein the first PPDU is received by the communication node before the second PPDU; wherein the communication node's current NAV is updated based on the first PPDU; and

a processor configured to ignore the current NAV and perform a concurrent transmission by the communication node if the communication node satisfies a condition for allowing the concurrent transmission.

8. The communications node of claim 7, wherein said processor is further configured to ignore the current NAV according to one of:

if the ending time of the current NAV is earlier than or equal to the ending time of the TXOP corresponding to the second PPDU or the carried NAV Duration, ignoring the current NAV;

9. The communications node according to claim 7 or 8, wherein the condition for allowing concurrent transmission comprises: if the current CCA threshold value of the communication node is set to be larger than a certain preset value, when the communication node detects that the received RSSI of the second PPDU is smaller than or equal to the current CCA threshold value of the communication node or the increased CCA threshold value; or the communication node is in a CCA idle (CCA idle) state, or a concurrent transmission link potentially established by the communication node is a near point communication link, or a received second PPDU indicates that concurrent transmission is allowed, or the like.

10. The communications node of any of claims 7 to 9, wherein the 802.11ax format PPDU comprises a data Frame, a control Frame such as RTS or CTS or Trigger Frame, or a management Frame; the Legacy PPDU includes a control frame such as an RTS, CTS, or Trigger frame, or a management frame.

11. The communication node of any of claims 7-10, wherein the first PPDU and the second PPDU are from an OBSS of the communication node in a WLAN.

12. A STA or AP as claimed in any one of claims 7 to 11, wherein the current NAV is set by the communication node for PPDUs from all OBSSs's, or from a certain one or group of the communication nodes, from a local BSS, or from a group of OBSSs's, from the communication node.