CN111757533B

CN111757533B - Method and equipment for sending PPDU (PPDU) in wireless local area network

Info

Publication number: CN111757533B
Application number: CN201910239916.5A
Authority: CN
Inventors: 桑燃; 陈维熙; 王云贵
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-03-27
Filing date: 2019-03-27
Publication date: 2023-02-07
Anticipated expiration: 2039-03-27
Also published as: CN111757533A

Abstract

The application provides a method and equipment for sending a PPDU in a wireless local area network. Wherein, the method comprises the following steps: the first device determines a target MPDU, wherein the target MPDU is an MPDU to be sent or an MPDU generated according to the MPDU to be sent, and the receiver address of the MPDU to be sent is the address of the second device; transmitting a first PPDU, the first PPDU including only a target MPDU; and after receiving the response frame of the first PPDU, sending a second PPDU, wherein the receiver address of the second PPDU is the address of the second equipment, the sending duration of the second PPDU is longer than that of the first PPDU, and the interval between the response frame of the first PPDU and the second PPDU is SIFS. The method can solve the problem of low transmission efficiency caused by channel conflict and effectively improve the transmission efficiency.

Description

Method and equipment for sending PPDU (PPDU) in wireless local area network

Technical Field

The present application relates to the field of wireless communications technologies, and in particular, to a method and a related device for sending a wireless local area network PPDU.

Background

Currently, wireless Local Area Network (WLAN) technology has been widely applied to enterprise networks and various operator networks. Since the WLAN uses specific wireless channel resources as a transmission medium, the WLAN network is susceptible to strong interference, which is also one of the key factors affecting the throughput performance of the WLAN network.

In a high-density networking environment, multi-Access Point (AP) and multi-user concurrency will cause the inter-link interference to increase greatly. Because the WLAN system uses a carrier sense multiple access/collision avoidance (CSMA/CA) method to contend for accessing a wireless channel, if the same backoff time is selected during a random backoff process and a service is initiated simultaneously after the backoff is finished, a collision will occur, that is, a plurality of users occupy the same wireless resource and initiate a service at the same time, thereby causing mutual interference between transmission links. Referring to fig. 1, as shown in fig. 1, it can be seen that, under the condition that a minimum value of a Contention Window (CW) is 4 slots (slots) and a maximum value is 6 slots, as more and more devices in a network, that is, a load is larger and larger, a collision rate is higher and higher, and when the number of the devices is 8, the collision rate reaches 0.38, which seriously affects transmission efficiency of a physical layer convergence protocol data unit (PPDU).

How to effectively solve the PPDU transmission conflict and improve the PPDU transmission efficiency is a technical problem which is not solved at present.

Disclosure of Invention

The application provides a method and equipment for sending a PPDU (direct protocol Unit) in a wireless local area network, which can solve the problem of low transmission efficiency caused by channel conflict and effectively improve the transmission efficiency.

In a first aspect, a method for transmitting a PPDU in a wireless local area network is provided, where the method includes: the method comprises the steps that a first device determines a target medium access control protocol data unit (MPDU), wherein the target MPDU is an MPDU (media access control protocol data unit) in an MPDU to be sent or an MPDU generated according to the MPDU to be sent, and the address of a receiver of the MPDU to be sent is the address of a second device; the first device sends a first physical layer convergence protocol data unit (PPDU), wherein the first PPDU only includes the target MPDU; after receiving the response frame of the first PPDU, the first device sends a second PPDU, a receiver address of an MPDU in the second PPDU is an address of the second device, a sending time duration of the second PPDU is greater than a sending time duration of the first PPDU, and an interval between the response frame of the first PPDU and the second PPDU is a short interframe space (SIFS).

In the scheme provided by the application, the first device firstly sends the first PPDU with shorter sending time length meeting the condition, and sends the second PPDU after receiving the response frame of the first PPDU, so that the channel quality can be rapidly detected, the long-time invalid sending under the condition of conflict is avoided, and the transmission efficiency is effectively improved.

With reference to the first aspect, in a possible implementation manner of the first aspect, a transmission duration of a PPDU corresponding to the target MPDU is less than a threshold.

In the scheme provided by the application, the threshold value is preset to ensure that the determined target MPDU meets the condition, the sending time of the corresponding PPDU is small enough, whether the conflict exists can be more quickly detected, and the transmission efficiency is further improved.

With reference to the first aspect, in a possible implementation manner of the first aspect, the threshold is a fixed duration value.

In the scheme provided by the application, a fixed time length value is set as a threshold value, and the condition that the sent first PPDU meets the condition is ensured by comparing the fixed time length value with the threshold value, so that the method is simple to realize and can improve the efficiency.

With reference to the first aspect, in a possible implementation manner of the first aspect, the threshold is a variable time length value based on a maximum PPDU time length, and a ratio of the threshold to the maximum PPDU time length is a preset value.

In the scheme provided by the application, the threshold can be still dynamically adjusted under the condition that the total sending time of the PPDU corresponding to the MPDU to be sent exceeds the maximum PPDU time, and the reasonability of the determined threshold is ensured, so that the target MPDU determined according to the threshold still meets the condition.

With reference to the first aspect, in a possible implementation manner of the first aspect, if a total transmission time duration of PPDUs corresponding to the MPDUs to be transmitted is less than a maximum PPDU time duration, a ratio of the threshold to a difference is the preset value, and the difference is obtained by subtracting the threshold from the total transmission time duration.

In the scheme provided by the application, the threshold can be still dynamically and reasonably determined under the condition that the total sending time of the PPDU corresponding to the MPDU to be sent is less than the maximum PPDU time, the sending time of the first PPDU to be sent is short, and the channel quality is quickly detected.

With reference to the first aspect, in a possible implementation manner of the first aspect, before the first device determines a target MPDU, the method further includes: the first equipment determines whether the total sending time length of a PPDU corresponding to the MPDU to be sent is greater than a first time length; and when the total sending time length is greater than the first time length according to the determination result, the first device determines the target MPDU.

In the scheme provided by the application, the first device determines the target MPDU by judging in advance that the total transmission time of the PPDU corresponding to the MPDU to be transmitted is longer than the first time, so that the problem of reduction of transmission efficiency caused by the fact that the total transmission time of the MPDU to be transmitted is too short can be avoided.

With reference to the first aspect, in a possible implementation manner of the first aspect, the determining, by the first device, the target MPDU includes: if the transmission time corresponding to a first MPDU in the MPDUs to be transmitted is greater than the threshold, fragmenting a medium access control service data unit (MSDU) or a medium access control management protocol data unit (MMPDU) in the first MPDU by the first device to obtain at least two fragmented MPDUs, wherein the target MPDU is a second MPDU in the at least two fragmented MPDUs, and the transmission time of the second MPDU is less than or equal to the threshold; the second PPDU comprises all MPDUs of the at least two fragmented MPDUs except the second MPDU.

In the scheme provided by the application, when the sending time corresponding to any one MPDU is longer than the threshold, the MPDU can be fragmented to obtain the target MPDU meeting the condition, so that the sending of the null data frame or the PPDU with the sending time exceeding the threshold is avoided, and the transmission efficiency can be further improved.

In a second aspect, a WLAN device is provided, which is applied to implement the method described in the first aspect. The WLAN device includes:

the processing module is used for determining a medium access control protocol data unit (MPDU), wherein the MPDU is an MPDU in an MPDU to be sent or an MPDU generated according to the MPDU to be sent, and a receiver address of the MPDU to be sent is an address of second equipment;

a sending module, configured to send a first physical layer convergence protocol data unit PPDU, where the first PPDU only includes the target MPDU;

a receiving module, configured to receive a response frame of the first PPDU;

the sending module is further configured to send a second PPDU, a receiver address of an MPDU in the second PPDU is an address of the second device, a sending duration of the second PPDU is longer than a sending duration of the first PPDU, and an interval between a response frame of the first PPDU and the second PPDU is a short interframe space SIFS.

In an optional implementation manner, a transmission duration of a PPDU corresponding to the target MPDU is less than a threshold.

In an optional implementation manner, the threshold is a variable time length value based on a maximum PPDU time length, and a ratio of the threshold to the maximum PPDU time length is a preset value.

In an optional implementation manner, if the total transmission time length of the PPDU corresponding to the MPDU to be transmitted is less than the maximum PPDU time length, the ratio of the threshold to the difference is the preset value, and the difference is obtained by subtracting the threshold from the total transmission time length.

In an optional implementation manner, the processing module is further configured to determine whether a total transmission duration of a PPDU corresponding to the MPDU to be transmitted is greater than a first duration; and when the total sending time length is greater than the first time length as a result of the determination, the processing module determines the target MPDU.

In an optional implementation manner, the processing module is further configured to fragment a medium access control service data unit (MSDU) or a medium access control management protocol data unit (MMPDU) in a first MPDU of an MPDU to be transmitted to obtain at least two fragmented MPDUs, where the target MPDU is a second MPDU of the at least two fragmented MPDUs, and a transmission time length of the second MPDU is less than or equal to the threshold; the second PPDU includes all MPDUs of the at least two fragmented MPDUs except for the second MPDU.

In a third aspect, a WLAN device is provided, which is applied to implement the method described in the first aspect. The WLAN device includes: a WLAN chip and an antenna, the WLAN chip and the antenna being connected to each other, the WLAN chip being configured to perform the method according to the first aspect.

In a fourth aspect, a WLAN chip system is provided, where the chip system includes at least one processor, a memory, and an interface circuit, where the memory, the interface circuit, and the at least one processor are interconnected by a line, and where the at least one memory has instructions stored therein; the instructions, when executed by the processor, implement the method of the first aspect.

In a fifth aspect, a computer program product is provided comprising instructions which, when run on an electronic device, cause the electronic device to perform the method of the first aspect.

In this application, the names of the first device, the second device, and the WLAN device do not limit the devices themselves, and in actual implementations, these devices may appear by other names. Provided that the function of each device is similar to that of the present application, and that the devices are within the scope of the claims of the present application and their equivalents.

Drawings

Fig. 1 is a schematic diagram illustrating a relationship between the number of devices and a collision rate according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a communication system according to an embodiment of the present application;

fig. 3 is a schematic view of a channel collision scenario provided in an embodiment of the present application;

fig. 4A is a schematic diagram illustrating successful transmission of handshake according to an embodiment of the present application;

fig. 4B is a schematic diagram of a handshake failure transmission according to an embodiment of the present application;

FIG. 5 is a schematic diagram illustrating a conflict generation according to an embodiment of the present application;

fig. 6 is a flowchart illustrating a method for sending a PPDU in a wireless local area network according to an embodiment of the present application;

fig. 7 is a schematic diagram illustrating a relationship between transmission efficiency and PPDU transmission duration according to an embodiment of the present application;

fig. 8A is a diagram illustrating a collision-free transmission according to an embodiment of the present application;

fig. 8B is a schematic diagram of a transmission with collision according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a WLAN device according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a WLAN device according to an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

The technical solution of the embodiment of the present application may be applied to a 5G New Radio (NR) Radio access technology system, and may also be applied to other communication systems, as long as there is indication information that one entity needs to send a transmission direction in the communication system, and another entity needs to receive the indication information, and determine the transmission direction within a certain time according to the indication information.

In a specific embodiment, as shown in fig. 2, the first device and the second device constitute a communication system. In the communication system, the first device may be a network device, such as an access point AP, or a terminal device, such as a User Equipment (UE) or a mobile Station (STA), and the second device may be a network device or a terminal device. When the first device is a terminal device, the second device may be a network device, the first device may send uplink data to the second device, and the second device needs to receive the uplink data sent by the first device. When the first device is a network device, the second device may be a terminal device, the first device may send downlink data to the second device, and the second device needs to receive the downlink data sent by the first device.

The first device or the second device related to the embodiments of the present application may be an entity for transmitting and receiving signals on a network side, and the first device or the second device may be a device for communicating with a mobile device, such as an AP in a WLAN, or a relay station, etc. In addition, in this embodiment of the present application, the network device may provide a service for a cell, and the terminal device communicates with the network device through a transmission resource (for example, a frequency domain resource, or a spectrum resource) used by the cell, where the cell may be a cell corresponding to a network device (for example, an AP), and the cells may include: microcells (microcells), picocells (picocells), femtocells (femtocells), and the like, which have the characteristics of small coverage area and low transmission power and are suitable for providing high-rate data transmission services.

The first device or the second device related to the embodiment of the present application may also be an entity for receiving or transmitting a signal at a user side, such as a new generation user equipment (new generation UE, ge UE). The first device or the second device may also be referred to as a terminal equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment. The first device or the second device may be a Station (STA) in a WLAN, and may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA) device, a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, or a next generation communication system, for example, a terminal device in a 5G network or a terminal device in a future-evolution Public Land Mobile Network (PLMN) network, or a terminal device in an NR communication system, and the like. By way of example and not limitation, in embodiments of the present application, the first device or the second device may also be a wearable device. Wearable equipment can also be called wearable intelligent equipment, is the general term of applying wearable technique to carry out intelligent design, develop the equipment that can dress to daily wearing, like glasses, gloves, wrist-watch, dress and shoes etc.. The wearable device may be worn directly on the body or may be a portable device integrated into the user's clothing or accessory. The wearable device is not only a hardware device, but also realizes powerful functions through software support, data interaction and cloud interaction. The generalized wearable smart device includes full functionality, large size, and can implement full or partial functionality without relying on a smart phone, such as: smart watches or smart glasses and the like, and only focus on a certain type of application function, and need to be matched with other equipment such as a smart phone for use, such as various smart bracelets for physical sign monitoring, smart jewelry and the like.

To facilitate an understanding of the present application, relevant technical knowledge related to embodiments of the present application will be first introduced herein.

Referring to fig. 3, fig. 3 is a schematic diagram of a channel collision scenario. As shown in fig. 3, AP1 is associated with STA1, AP2 is associated with STA2, after confirming that a channel is idle, AP1 and AP2 wait for the same Distributed Inter Frame Space (DIFS), perform Backoff (BO), and wait for the same random time, and then AP1 and AP2 initiate services simultaneously, that is, AP1 and AP2 transmit data to respective associated terminals STA1 and STA2 simultaneously, STA1 receives the signal of AP2 while receiving the signal of AP1, and the two signals interfere with each other, resulting in failure of STA1 to decode the signal of AP 1.

To avoid collisions, a "Request To Send (RTS) -Clear To Send (CTS) handshake mechanism" is used to resolve collisions. The sending end sends a small RTS frame to the target end before sending the data frame, the current channel is considered to be free of interference after the target end responds to the CTS frame, the sending of the data frame is started, if the CTS frame responded by the target end is not received, the current channel is considered to be interfered, the transmission opportunity is given up, and the channel is intercepted and competed again. The RTS and the CTS carry predicted time, when receiving the signals, nodes of non-target addresses do not send the signals in the time, and once the RTS-CTS handshake succeeds, the nodes can ensure that no conflict is generated in the subsequent data frame sending process. Referring to fig. 4A, fig. 4A is a diagram illustrating successful transmission of a handshake. As shown in fig. 4A, the sending end detects the channel condition before transmission, waits for DIFS and then detects again if the channel condition is unoccupied, confirms that the channel is idle and goes back if the channel condition is not occupied, waits for a random time and then starts to send an RTS frame, the target end returns to a CTS frame after receiving the RTS frame, and the sending end starts to send a data frame after receiving the CTS frame. Referring to fig. 4B, fig. 4B is a diagram illustrating a handshake failure transmission. As shown in fig. 4B, the transmitting end detects the channel condition before transmission, waits for DIFS and then detects again if the channel condition is not occupied, confirms that the channel is free and goes back if the channel condition is not occupied, starts to send an RTS frame after waiting for a random time, the target end does not return a CTS frame, and waits for timeout, the transmitting end needs to contend for the channel again, at this time, the CW needs to be doubled, for example, 32 time slots originally, and 64 time slots now need to be enlarged.

The RTS frame and the CTS frame are transmitted by using a low-order Modulation and Coding Scheme (MCS), so that more redundancy is increased, higher reliability is ensured, the requirement on channel conditions is lower, the corresponding demodulation threshold is lower, and demodulation can be successful at a lower signal-to-interference noise ratio (SINR). The data frame is generally transmitted by adopting a high-order MCS, the transmission efficiency is high, the reliability is low, the requirement on the channel condition is high, the corresponding demodulation threshold is high, and the data frame can be successfully demodulated only under the condition of high SINR. Because the MCS adopted by the RTS frame and the CTS frame is different from the MCS adopted by the data frame, collision may occur, which may cause transmission failure of the data frame and reduce transmission efficiency of the channel. Referring to fig. 5, fig. 5 is a schematic diagram of a collision generation. As shown in fig. 5, AP1 and AP2 back off simultaneously, and after waiting for the same random time, they initiate services simultaneously, that is, AP1 sends an RTS frame to its associated STA1, AP2 sends a data frame to its associated device simultaneously, and AP2 is a collision source. The distance between the AP2 and the STA1 is relatively long, so the strength of a signal sent by the AP2 is relatively weak, because the demodulation threshold of the RTS frame is relatively low, for the STA1, the RTS frame sent by the AP1 may be received and demodulated, a CTS frame is replied to the AP1 after demodulation, after receiving the CTS frame, the AP1 considers that the current channel is idle, and continues to send a data frame to the STA1, because the demodulation threshold of the data frame is relatively high, after the STA1 receives the data frame, the STA1 cannot demodulate the received data frame due to interference of a collision source (AP 2), and finally transmission fails. In addition, if the data frame is too large, it may be determined that the channel has a collision after a long time, which may waste the channel transmission resource and reduce the channel transmission efficiency.

In order to solve the above problem, the present application provides a method and a device for sending a PPDU in a WLAN, which can solve the problem of low transmission efficiency caused by channel collision and effectively improve the transmission efficiency.

Referring to fig. 6, fig. 6 is a flowchart illustrating a method for transmitting a PPDU in a WLAN according to an embodiment of the present application. The first device and the second device described in fig. 6 may correspond to the first device and the second device shown in fig. 2, respectively. As shown in fig. 6, the method includes, but is not limited to, the following steps:

s601: the first device determines a target medium access control protocol data unit (MPDU).

Specifically, the MPDU may be an MPDU in an MPDU to be transmitted or an MPDU generated from the MPDU to be transmitted, and a receiver address of the MPDU to be transmitted is an address of the second device.

Optionally, the target MPDU determined by the first device satisfies a condition, where the condition may be that a transmission time length of a physical layer convergence protocol data unit (PPDU) corresponding to the target MPDU is less than a threshold.

In a specific embodiment, the threshold may be a fixed duration value. It can be understood that the first device may determine the target MPDU or PPDU meeting the condition more quickly by presetting a fixed duration value. Illustratively, if the preset fixed time length value is 1 ms, and the transmission time length of a PPDU corresponding to one MPDU in the MPDU to be transmitted is less than 1 ms, the first device uses the MPDU as a target MPDU meeting the condition. If the transmission duration of a PPDU corresponding to a plurality of MPDUs is less than 1 millisecond, one of the MPDUs can be randomly selected as a target MPDU meeting the condition.

In a specific embodiment, the threshold may be a variable time length value based on the maximum PPDU time length, and a ratio of the threshold to the maximum PPDU time length is a preset value.

Specifically, if the total transmission time of the PPDU corresponding to the MPDU to be transmitted is longer than the maximum PPDU time, that is, the transmission time of one PPDU formed after the MPDUs to be transmitted are aggregated exceeds the maximum PPDU time, the threshold may be determined according to a preset value, and a ratio of the threshold to the maximum PPDU time is the preset value. The preset value is a fixed value, and the specific size thereof is obtained through theoretical experience or experimental data, and may be, for example, 0.2 or 0.3, which is not limited in the present application.

For example, if the preset value is 0.3, and the maximum PPDU duration is 30 ms, the threshold should be 9 ms, and then the first device may select, as the target MPDU meeting the condition, the MPDU corresponding to the PPDU whose transmission duration is less than or equal to 9 ms. In the case that the maximum PPDU duration is 20 milliseconds, then the threshold should be 6 milliseconds, and then the first device may select an MPDU corresponding to a PPDU whose transmission duration is less than or equal to 6 milliseconds as a target MPDU that satisfies the condition.

It can be understood that the first device may, under the condition that the total transmission duration of the PPDU corresponding to the MPDU to be transmitted exceeds the maximum PPDU duration, dynamically adjust the threshold according to the maximum PPDU duration, ensure the reasonability of the determined threshold, and further ensure that the target MPDU determined by the threshold satisfies the condition.

In a specific embodiment, if the total transmission time length of the PPDU corresponding to the MPDU to be transmitted is less than the maximum PPDU time length, the ratio of the threshold to the difference is the preset value, and the difference is obtained by subtracting the threshold from the total transmission time length, so as to determine the threshold.

Specifically, if the sending time length of a PPDU formed after aggregation of MPDUs to be sent is less than the maximum PPDU time length, the threshold may still be determined according to the preset value, and the ratio of the threshold to the difference is the preset value. The preset value is a fixed ratio as the characteristic of the preset value, and the specific size is obtained through theoretical experience or experimental data, which is not limited in the present application.

For example, if the total transmission time length of the PPDU corresponding to the MPDU to be transmitted is 30 milliseconds and the preset value is 0.2, the calculated available threshold is 5 milliseconds, and the first device may select, as the target MPDU meeting the condition, the MPDU corresponding to the PPDU of which the transmission time length is less than or equal to 5 milliseconds. If the total transmission duration of the PPDU corresponding to the MPDU to be transmitted is 24 milliseconds, the calculated available threshold is 4 milliseconds, and then the first device may select, as the target MPDU that satisfies the condition, the MPDU corresponding to the PPDU whose transmission duration is less than or equal to 4 milliseconds.

It can be understood that, under the condition that the total sending time of the PPDU corresponding to the MPDU to be sent changes, the threshold value can be dynamically adjusted in real time according to the preset value, so as to ensure the reasonability of the determined threshold value, and further ensure that the target MPDU determined by the threshold value meets the condition.

Optionally, before determining the target MPDU, the first device determines whether a total transmission duration of a PPDU corresponding to the MPDU to be transmitted is greater than a first duration, and determines the target MPDU meeting the condition only when the determination result is that the total transmission duration is greater than the first duration.

Illustratively, the first duration is 20 milliseconds, and the MPDUs to be transmitted are MPDU1, MPDU2, and MPDU3. The MPDU1, the MPDU2 and the MPDU3 are aggregated to form the PPDU1, the sending time corresponding to the PPDU1 is 25 milliseconds, and the sending time corresponding to the PPDU1 exceeds the first time, so that the first device can process the MPDU1, the PPDU2 and the MPDU3 to form a target MPDU meeting the condition. For example, if the threshold is 10 milliseconds, the PPDU transmission duration corresponding to the MPDU1 is 5 milliseconds, the PPDU transmission duration corresponding to the MPDU2 is 8 milliseconds, and the PPDU transmission duration corresponding to the MPDU3 is 12 milliseconds, the first device may determine the MPDU1 as a target MPDU that satisfies the condition, and aggregate the remaining

MPDUs

2 and 3 to form the PPDU2, or the first device may also determine the MPDU2 as a target MPDU that satisfies the condition and aggregate the remaining

MPDUs

1 and 3 to form the PPDU3. The present application does not limit the specific selection process of the target MPDU that satisfies the condition.

It is worth to be noted that, under the condition that the total sending time length of the PPDU corresponding to the MPDU to be sent is equal to the first time length, the benefits of the conventional technical scheme and the technical scheme provided by the present application are the same, that is, the transmission efficiencies of the two schemes are equal, and under the condition that the total sending time length is greater than the first time length, the technical scheme provided by the present application is superior to the conventional technical scheme, that is, the transmission efficiency is higher than the conventional technical scheme. The first duration is a duration obtained by the first device through calculation in advance based on parameters such as a threshold value and a collision rate, specifically, a traditional technical scheme is utilized to aggregate MPDUs to be transmitted and then form a PPDU to transmit, so that a transmission efficiency can be obtained through calculation, for example, the total transmission duration of the PPDU corresponding to the MPDU to be transmitted is a millisecond (a represents that the total transmission duration is an unknown number), the corresponding transmission efficiency can be calculated, and formula 1 including a is obtained; then, by using the technical scheme provided by the application, the MPDU to be transmitted is divided into two parts to be transmitted, one part is the size of the threshold, the other part is the total transmission time length minus the threshold (namely, A minus the threshold), the corresponding transmission efficiency is calculated to obtain another equation 2 containing A, the equation 1 is equal to the equation 2 to obtain an equation, and because the equation only contains A unknown number, the value of A can be calculated, and is the first time length.

It should be appreciated that encapsulating the MPDU to be transmitted into a PPDU to be transmitted adds a Physical Layer Convergence Protocol (PLCP) header, a check field, and the like, which increases additional overhead. If the total transmission time length of the PPDU corresponding to the MPDU to be transmitted is too short, in this case, if the MPDUs to be transmitted are aggregated to form two or more PPDUs, the transmission efficiency of the channel may be reduced, and the benefit may not be improved, so that the first device determines the target MPDU meeting the condition only in response to a determination result that the total transmission time length is greater than the first time length.

In a specific embodiment, if the transmission duration corresponding to a first MPDU in the MPDUs to be transmitted is greater than the threshold, the first device fragments a medium access control service data unit (MSDU) or a medium access control management protocol data unit (MMPDU) in the first MPDU to obtain at least two fragmented MPDUs, where the target MPDU is a second MPDU in the at least two fragmented MPDUs, and the transmission duration of the second MPDU is less than or equal to the threshold; the second PPDU comprises all MPDUs of the at least two fragmented MPDUs except the second MPDU.

Specifically, if an MPDU (i.e., a first MPDU) whose transmission duration is greater than a threshold exists in the MPDUs to be transmitted, the MPDUs may be fragmented to obtain at least two fragmented MPDUs, and an MPDU (i.e., a second MPDU) whose transmission duration is less than or equal to the threshold is selected as a target MPDU from the fragmented MPDUs. It should be understood that if there are a plurality of first MPDUs with a transmission duration greater than the threshold in the MPDU to be transmitted, one may be randomly selected for fragmentation, and if there are a plurality of second MPDUs with a transmission duration less than or equal to the threshold in the fragmented MPDU, one may also be randomly selected as the target MPDU, which is not limited in this application. And after the selection is completed, aggregating the rest fragmented MPDUs with other MPDUs to be sent to form a second PPDU.

Further, the MPDU is formed by adding a Medium Access Control (MAC) header and an integrity check field, etc. to the MSDU or MMPDU. When the first MPDU is fragmented, the data of the MSDU or MMPDU is divided into two or more parts, and a new MPDU is formed by adding a MAC header and an integrity check field to each part.

Illustratively, the threshold is 10 ms, the MPDUs to be transmitted are MPDU1, MPDU2 and MPDU3, where the transmission time of PPDU1 corresponding to MPDU1 is 12 ms, the transmission time of PPDU2 corresponding to MPDU2 is 14 ms, and the transmission time of PPDU3 corresponding to MPDU3 is 18 ms, the first device performs fragmentation processing on MPDU1, and divides MPDU1 into two parts (or may be divided according to other rules) on average to obtain MPDU4 and MPDU5, the transmission times of PPDU4 and PPDU5 corresponding to MPDU4 and MPDU5 are both 7 ms and both are smaller than the threshold, the first device determines MPDU4 (or MPDU 5) as a target MPDU meeting the condition, and the first device aggregates MPDU5 and MPDU2 and MPDU3 to form a new PPDU6.

It can be understood that, when the sending time of the PPDU corresponding to the first MPDU in the MPDU to be sent is longer than the threshold, the first MPDU may be fragmented to obtain the target MPDU meeting the condition, and in addition, the target MPDU meeting the condition may also be directly sent after the target MPDU meeting the condition is obtained, so that waste of transmission resources caused by sending an empty data frame and the like is avoided, and transmission efficiency is further improved.

S602: the first device transmits a first physical layer convergence protocol data unit (PPDU).

Specifically, the first device, after determining a target MPDU that satisfies a condition, adds a PLCP header or the like to the target MPDU that satisfies the condition to form a first PPDU, and transmits the first PPDU. It is worth noting that only the target MPDUs satisfying the condition are included in the first PPDU.

S603: determining whether a response frame of the first PPDU is received, if the response frame of the first PPDU is received, performing step S604, and if the response frame of the first PPDU is not received, performing step S605.

S604: and transmitting the second PPDU.

Specifically, if a target MPDU satisfying the condition in the first PPDU transmitted by the first device is formed without aggregation, the first device transmits the second PPDU after receiving an Acknowledgement (ACK) of the first PPDU. If a target MPDU meeting a condition in a first PPDU transmitted by a first device is an AMPDU formed by aggregating a plurality of MPDUs, for example, two MPDUs are aggregated to form one AMPDU, and a transmission time length of a corresponding PPDU is still smaller than a threshold, the first device transmits a second PPDU after receiving a Block Acknowledgement (BA) of the first PPDU.

Further, a receiver address of an MPDU in the second PPDU is an address of the second device, a transmission duration of the second PPDU is longer than a transmission duration of the first PPDU, and an interval between a response frame of the first PPDU and the second PPDU is a short interframe space (SIFS).

S605: the channel is contended again.

If the first device does not receive the response frame of the first PPDU after the waiting time is exceeded after the first PPDU is sent, it indicates that the current channel has a collision, a backoff algorithm needs to be executed to perform backoff, the channel is contended again, and the above processes are repeatedly executed.

It can be understood that the sending duration of the first PPDU is short, the first device detects the channel quality by sending the first PPDU first, if the response frame of the first PPDU is received, it is indicated that the current channel quality is good, and there is no collision, continue to send the second PPDU, ensure that the channel quality is not interfered and can be received smoothly in the process of sending the second PPDU, if the response frame of the first PPDU is not received, it is indicated that the current channel quality is poor, and there may be a collision, stop sending the second PPDU, re-compete for the channel, ensure that the use of channel resources can be stopped in time, avoid still occupying the channel for a long time under scenes such as a collision, and improve the transmission efficiency of the channel.

It should be understood that steps S601 to S605 related to the above method embodiment are merely schematic descriptions and generalizations, and should not constitute a specific limitation, and the steps related to may be added, reduced or combined as needed.

Now, based on the method of transmitting PPDUs in a WLAN shown in fig. 6, how to improve transmission efficiency in a collision scenario will be described. For convenience of understanding, the first device is taken as an AP as an example, and the second device is taken as an STA as an example.

The AP needs to send data to the STA, and if data to be sent (MPDU) is aggregated to form a PPDU1 for sending, the sending duration is T1. If the MPDU to be transmitted is divided into two parts to be transmitted, the MPDUs to be transmitted are aggregated to form PPDU2 and PPDU3, the corresponding transmission durations are T2 and T3, respectively, wherein T2 is less than T3. The transmission efficiency of the two situations in the scene with conflict is calculated respectively. For the first case, the MPDUs to be transmitted are aggregated to form a PPDU1 for transmission, and the transmission efficiency is calculated according to the following formula 1:

for the second case, namely aggregating MPDUs to be transmitted to form PPDU2 and PPDU3 respectively for transmission, the transmission efficiency is calculated according to the following formula 2:

where ECR is a symbol indicating a collision rate, T4 indicates a transmission time period required to transmit PPDU2, T4= T0+ T2, T5 indicates a transmission time period required to transmit PPDU3, T5= T0+ T3, T6 indicates a transmission time period required to transmit PPDU1, and T6= T1+ T0. Wherein T0 represents the overhead required for transmitting the data packet corresponding to the PPDU, and the transmitted PPDU may be PPDU1, PPDU2 or PPDU3, that is, the overhead required for each transmission is the same, where T0= access preamble duration + SIFS + BA, SIFS represents a short inter-frame interval, and BA represents block response duration.

Further, the transmission efficiency calculation for the second case is simplified, that is, equation 2 is simplified to obtain the following equation 3:

it should be understood that the transmission efficiency can be calculated separately for two different situations by the above formula. Now, assuming that ECR is 0.15 and the transmission duration corresponding to PPDU1 is 150 μ sec, the transmission efficiencies in the two cases are calculated respectively, see fig. 7, and fig. 7 is a schematic diagram illustrating a functional relationship between the calculated transmission efficiency and the total PPDU transmission duration (i.e., T1). As shown in fig. 7, it can be seen that, as T1 increases continuously, transmission efficiencies in both cases increase, when T1 is 1000 microseconds, the transmission efficiencies corresponding to the two cases are equal, and when T1 is less than 1000 microseconds, the transmission efficiency corresponding to the first case is higher than the transmission efficiency corresponding to the second case, that is, when the total transmission duration of the MPDU to be transmitted is too short, if the MPDUs to be transmitted are aggregated to form two or more PPDUs, the transmission efficiency will be lower than the transmission efficiency corresponding to the formation of one PPDU by aggregating the MPDUs to be transmitted. When T1 is greater than 1000 microseconds, the transmission efficiency corresponding to the first case will be lower than the transmission efficiency corresponding to the second case, that is, it is stated that, under the condition that the total transmission time of the MPDU to be transmitted is too long, if the MPDUs to be transmitted are aggregated to form two PPDUs, the transmission efficiency will be improved, and as T1 becomes larger, the corresponding transmission efficiency is improved more significantly, and when T1 reaches 2000 microseconds, the corresponding transmission efficiency can reach 0.86.

Therefore, before the AP sends data to the STA, it is pre-calculated to determine whether the total sending duration of the PPDU corresponding to the MPDU to be sent is greater than 1000 microseconds, and after it is determined that the total sending duration is greater than 1000 microseconds, a target MPDU meeting the conditions is determined, so as to form a PPDU1 and a PPDU2, as shown in fig. 8A, the AP detects a channel condition, if the channel condition is idle, detects again after waiting for a DIFS, and if the channel condition is still idle, performs backoff, after waiting for a random time, sends the PPDU1, after receiving the PPDU1 and successfully demodulating, the STA returns an ACK response frame for the PPDU1, after receiving the ACK response frame returned by the STA, the AP continues to send the PPDU2, and after continuing to receive the PPDU2 and successfully demodulating, the STA returns the ACK response frame for the PPDU2 again. It can be understood that the above-mentioned sending process is performed in a scenario where no collision occurs, if there is a collision, see fig. 8B, as shown in fig. 8B, if there is a collision source AP1, when the AP sends PPDU1 to the STA, the collision source AP1 also initiates a service at the same time, for the STA, when receiving PPDU1 sent by the AP, the STA also receives data sent by the AP1, so that the STA cannot successfully demodulate PPDU1, therefore, the STA will not return an ACK response frame for PPDU1, after waiting for timeout, the AP determines that there is a collision in the current channel, stops sending PPDU2, re-competes for the channel, and waits for the next sending.

It can be understood that when the data volume to be sent is too large, the data volume to be sent is divided into two parts, the part with the smaller data volume is sent first to detect the channel quality, the part with the larger data volume is sent after the success, and the sending is stopped if the failure occurs, so that the transmission efficiency can be effectively improved.

In order to facilitate better implementation of the above-described aspects of the embodiments of the present application, the following also provides relevant means for implementing the above-described aspects in a coordinated manner, accordingly.

Referring to fig. 9, fig. 9 is a schematic structural diagram of a WLAN device according to an embodiment of the present application. As shown in fig. 9, the WLAN device 900 includes: a transmitting module 910, a receiving module 920 and a processing module 930; wherein:

a processing module 930, configured to determine a target mac protocol data unit MPDU, where the target MPDU is an MPDU in an MPDU to be sent or an MPDU generated according to the MPDU in the MPDU to be sent, and a receiver address of the MPDU to be sent is an address of a second device;

a sending module 910, configured to send a first physical layer convergence protocol data unit PPDU, where the first PPDU only includes the target MPDU;

a receiving module 920, configured to receive a response frame of the first PPDU;

the sending module 910 is further configured to send a second PPDU, where a receiver address of an MPDU in the second PPDU is an address of the second device, a sending duration of the second PPDU is longer than a sending duration of the first PPDU, and an interval between a response frame of the first PPDU and the second PPDU is a short interframe space SIFS.

Illustratively, the transmission duration of a PPDU corresponding to the target MPDU is less than a threshold.

Illustratively, the threshold is a variable time length value based on a maximum PPDU time length, and a ratio of the threshold to the maximum PPDU time length is a preset value.

Illustratively, if the total transmission duration of the PPDU corresponding to the at least one MPDU to be transmitted is less than the maximum PPDU duration, the ratio of the threshold to the difference is the preset value, and the difference is obtained by subtracting the threshold from the total transmission duration.

For example, the processing module 530 is further configured to determine whether a total transmission duration of PPDUs corresponding to the MPDU to be transmitted is greater than a first duration; and when the total sending time length is greater than the first time length as a result of the determination, the processing module determines the target MPDU.

Exemplarily, the processing module is further configured to fragment a medium access control service data unit (MSDU) or a medium access control management protocol data unit (MMPDU) carried in a first MPDU to obtain at least two fragmented second MPDUs, where the target MPDU is the second MPDU of which the fragmented transmission time length is less than or equal to the threshold, and the first MPDU is any one of the MPDUs to be transmitted; the second PPDU comprises all fragmented second MPDUs except the target MPDU.

The WLAN device 900 may perform the steps performed by the first device in the method for sending PPDU in the WLAN shown in fig. 6, which is not described herein again, for details, refer to fig. 6 and related contents. It should be understood that the transmitting module 910 and the receiving module 920 in the embodiments of the present application may be implemented by a transceiver or transceiver-related circuit components, and the processing module 930 may be implemented by a processor or processor-related circuit components.

Referring to fig. 10, fig. 10 is a schematic structural diagram of a WLAN device according to an embodiment of the present application. As shown in fig. 10, the WLAN device 100 includes a processor 110, a memory 120, and a transceiver 130, which are connected via a bus 140, wherein the memory 120 stores instructions or programs, and the processor 110 is configured to execute the instructions or programs stored in the memory 120. When the instructions or programs stored in the memory 120 are executed, the processor 110 is configured to perform the operations performed by the processing module 930 in the above embodiments, and the transceiver is configured to perform the operations performed by the transmitting module 910 and the receiving module 920 in the above embodiments.

It should be noted that the WLAN device 900 or the WLAN device 100 in the embodiment of the present application may correspond to the first device in the embodiment of the method provided in the present application, and operations and/or functions of each module in the WLAN device 900 or the WLAN device 100 are respectively for implementing corresponding flows of each method in fig. 1 to fig. 8B, and are not described herein again for brevity.

An embodiment of the present application further provides a WLAN device, where the WLAN device includes: the wireless communication device comprises a WLAN chip and an antenna, wherein the WLAN chip is configured to execute the flow related to the first device or the second device in the method for sending the PPDU provided by the method embodiment.

The embodiment of the present application further provides a WLAN chip system, where the chip system includes at least one processor, a memory, and an interface circuit, where the memory, the interface circuit, and the at least one processor are interconnected by a line, and the at least one memory stores instructions; the instructions, when executed by the processor, may implement a flow related to the first device or the second device in the method for sending PPDU provided by the above method embodiment.

Embodiments of the present application also provide a computer program product containing instructions, which when run on a computer or a processor, cause the computer or the processor to perform one or more steps of any of the above methods for transmitting PPDUs.

It should be understood that the processor mentioned in the embodiments of the present application may be a Central Processing Unit (CPU), and may also be other general purpose processors, digital Signal Processors (DSPs), application Specific Integrated Circuits (ASICs), field Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It will also be appreciated that the memory referred to in the embodiments herein may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, and not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), SLDRAM (synchronous DRAM), and direct rambus RAM (DR RAM).

It should be noted that when the processor is a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, the memory (memory module) is integrated in the processor.

It should be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should also be understood that reference herein to first, second, third, fourth, and various numerical numbering is merely for convenience of description and is not intended to limit the scope of the present application.

It should be understood that the term "and/or" herein is merely one type of association relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

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 technical solution. 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 application.

It can be clearly understood by those skilled in the art that, for convenience and simplicity 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 application 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 solutions of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

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

The modules in the device can be merged, divided and deleted according to actual needs.

The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for transmitting a physical layer convergence protocol data unit, PPDU, in a wireless local area network, WLAN, comprising:

the method comprises the steps that a first device determines a target medium access control protocol data unit (MPDU), wherein the target MPDU is an MPDU to be sent or an MPDU generated according to the MPDU to be sent, and the address of a receiver of the MPDU to be sent is the address of a second device;

the first device sends a first physical layer convergence protocol data unit (PPDU), wherein the first PPDU only comprises the target MPDU;

the first equipment judges whether a response frame of the first PPDU is received or not, if the response frame of the first PPDU is received, a second PPDU is sent, if the response frame of the first PPDU is not received, a channel is contended again, the address of a receiver of an MPDU in the second PPDU is the address of the second equipment, the sending time length of the second PPDU is longer than that of the first PPDU, and the interval between the response frame of the first PPDU and the second PPDU is a short interframe space SIFS.

2. The method of claim 1, wherein a transmission duration of a PPDU to which the target MPDU corresponds is less than a threshold.

3. The method of claim 2, wherein the threshold is a variable duration value based on a maximum PPDU duration, and a ratio of the threshold to the maximum PPDU duration is a preset value.

4. The method of claim 3, wherein if a total transmission duration of PPDUs corresponding to the MPDUs to be transmitted is less than a maximum PPDU duration, the ratio of the threshold to the difference is the predetermined value, and the difference is the total transmission duration minus the threshold.

5. The method of any of claims 2 to 4, wherein prior to the first device determining a target MPDU, the method further comprises:

the first equipment determines whether the total sending time length of a PPDU corresponding to the MPDU to be sent is greater than a first time length;

and when the total sending time length is greater than the first time length according to the determination result, the first device determines the target MPDU.

6. The method of any of claims 2 to 4, wherein the first device determining the target MPDU comprises:

if the transmission time corresponding to a first MPDU in the MPDUs to be transmitted is greater than the threshold, fragmenting a medium access control service data unit (MSDU) or a medium access control management protocol data unit (MMPDU) in the first MPDU by the first device to obtain at least two fragmented MPDUs, wherein the target MPDU is a second MPDU in the at least two fragmented MPDUs, and the transmission time of the second MPDU is less than or equal to the threshold;

the second PPDU comprises all MPDUs of the at least two fragmented MPDUs except the second MPDU.

7. A wireless local area network, WLAN, device, comprising:

the processing module is used for determining a target medium access control protocol data unit (MPDU), wherein the target MPDU is an MPDU (media-protocol data unit) in an MPDU to be sent or an MPDU generated according to the MPDU to be sent, and the receiver address of the MPDU to be sent is the address of a second device;

the processing module is configured to determine whether a response frame of the first PPDU is received;

the sending module is further configured to send a second PPDU if the response frame of the first PPDU is received, re-contend a channel if the response frame of the first PPDU is not received, where a receiver address of an MPDU in the second PPDU is an address of the second device, a sending duration of the second PPDU is longer than a sending duration of the first PPDU, and an interval between the response frame of the first PPDU and the second PPDU is a short interframe space SIFS.

8. The WLAN device of claim 7, wherein a transmission duration of a PPDU to which the target MPDU corresponds is less than a threshold.

9. The WLAN device of claim 8, wherein the threshold is a variable duration value based on a maximum PPDU duration, and a ratio of the threshold to the maximum PPDU duration is a preset value.

10. The WLAN device of claim 9, wherein if a total transmission duration of PPDUs corresponding to the MPDU to be transmitted is less than a maximum PPDU duration, the ratio of the threshold to the difference is the predetermined value, and the difference is the total transmission duration minus the threshold.

11. The WLAN device of any one of claims 8 to 10,

the processing module is further configured to determine whether a total sending duration of a PPDU corresponding to the MPDU to be sent is greater than a first duration;

and when the total sending time length is greater than the first time length as a result of the determination, the processing module determines the target MPDU.

12. The WLAN device of any one of claims 8 to 10, wherein the processing module is further configured to fragment a medium access control service data unit, MSDU, or a medium access control management protocol data unit, MMPDU, in a first MPDU of an MPDU to be transmitted to obtain at least two fragmented MPDUs, wherein the target MPDU is a second MPDU of the at least two fragmented MPDUs, and wherein a transmission duration of the second MPDU is less than or equal to the threshold; the second PPDU includes all MPDUs of the at least two fragmented MPDUs except for the second MPDU.

13. A wireless local area network, WLAN, device, comprising: a WLAN chip and an antenna, the WLAN chip and the antenna being interconnected, the WLAN chip being configured to perform the method of any one of claims 1 to 6.

14. A WLAN chip system, wherein the chip system includes at least one processor, a memory, and an interface circuit, the memory, the interface circuit, and the at least one processor are interconnected by a line, and the at least one memory stores instructions; the instructions, when executed by the processor, implement the method of any of claims 1 to 6.