CN108155975B

CN108155975B - Data transmission method, equipment and system

Info

Publication number: CN108155975B
Application number: CN201611108812.3A
Authority: CN
Inventors: 陈国海; 胡寅亮
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2016-12-06
Filing date: 2016-12-06
Publication date: 2021-03-05
Anticipated expiration: 2036-12-06
Also published as: CN108155975A

Abstract

The application discloses a data transmission method, equipment and a system, and belongs to the field of communication. The method comprises the following steps: sending a group inquiry frame to each station in a first group of stations, the group inquiry frame comprising: the first site group is any one of at least one site group obtained by dividing the sites associated with the point coordinator by the point coordinator, and the target sites are the sites in the first site group; receiving data sent by at least one target station according to the data sending sequence; according to the received data, sending a group acknowledgement frame to each station in the first station group, wherein the group acknowledgement frame comprises: site identification and data information for each of the at least one targeted site. The method and the device effectively improve the link utilization rate. The application is used for data transmission.

Description

Data transmission method, equipment and system

Technical Field

The present application relates to the field of communications, and in particular, to a data transmission method, device, and system.

Background

There are two Access modes for data transmission of Medium Access Control (MAC) in wlan: a Distributed Coordination Function (DCF) access mode and a Point Coordination Function (PCF) access mode. The access mode of the point coordination function provides services for services with high real-time performance, such as voice services, so as to improve the Quality of Service (QoS).

In the access mode of the Point coordination function, a Point Coordinator (PC) divides the channel time into a Contention Free Period (CFP) and a Contention Period (CP), and provides a certain Quality of Experience (QoE) for real-time service transmission by polling in the Contention Free Period, and a station competes for the channel by using a distributed coordination mechanism in the Contention Period. The polling specifically comprises: the point coordinator sends inquiry frames to all Stations (STA) in sequence, and allocates a sending opportunity window (TXOP) for the stations, so that the stations have an opportunity to send data frames to the point coordinator in one TXOP; then, the station to which the TXOP is allocated transmits a data frame to the point coordinator; finally, the point coordinator that receives the data frame sends an acknowledgement frame to the station to indicate that the data sent by the station was received.

In the point coordination function access mode, the transmission characteristics of the whole wireless local area network depend on the polling action of the point coordinator. If polling is evenly distributed, then bandwidth is evenly distributed to all stations. However, if some stations do not have data to send, but the point coordinator continues to poll it, additional overhead is incurred. These additional overheads may be accounted for by the total time to transmit data in the link, not accounting for the transmission time of valid data in the link. The percentage of the transmission time of the valid data in the link to the total time for transmitting the data is the link utilization rate. Therefore, the link utilization rate of data transmission in the access mode of the point coordination function is low.

Disclosure of Invention

In order to solve the problem of low link utilization rate in the prior art, embodiments of the present invention provide a data transmission method, device, and system. The technical scheme is as follows:

the data transmission system comprises at least one point coordinator and at least two stations, wherein each point coordinator provides services for the at least two stations.

In the data transmission system, the point coordinator manages the sites associated with the point coordinator in a unified manner, the sites associated with the point coordinator can be divided into at least one site group according to the adjacent position relationship between the sites associated with the point coordinator, a group inquiry frame is sent to the at least one site group, each site in the corresponding site group sends data to the point coordinator in sequence according to the data sending sequence of the sites in the group inquiry frame, and after the point coordinator receives the data sent by each site in the site group, a group confirmation frame is sent to each site in the first site group to indicate that the data sent by the site is received.

The station may send data to the point coordinators in the order specified in the group query frame after receiving the group query frame sent by the point coordinators.

In a first aspect, an embodiment of the present invention provides a data transmission method, which is applied to a point coordinator in a wireless local area network, where the method includes: sending a group inquiry frame to each station in a first group of stations, the group inquiry frame comprising: the first site group is any one of at least one site group obtained by dividing the sites associated with the point coordinator by the point coordinator, and the target sites are the sites in the first site group; receiving data sent by at least one target station according to the data sending sequence; according to the received data, sending a group acknowledgement frame to each station in the first station group, wherein the group acknowledgement frame comprises: site identification and data information for each of the at least one targeted site.

According to the scheme disclosed by the embodiment of the invention, as only one group inquiry frame is sent to one site group, compared with the prior art, the inquiry frames are not sent to each site one by one, so that the overhead generated by sending the inquiry frames to a plurality of sites one by one is reduced, links can be used for transmission of effective data as much as possible, and the link utilization rate is improved.

Optionally, before the sending the group query frame to the stations in the first station group, the method further includes: and dividing the sites associated with the point coordinators into at least one site group according to the adjacent position relationship between the sites associated with the point coordinators, wherein each site group comprises at least two adjacent sites.

It should be noted that, the sites associated with the point coordinator are divided into at least one site group, and in a query process, the point coordinator only needs to send a query frame and a confirmation frame to a plurality of sites in the site group.

The method of dividing the sites associated with the point coordinators into at least one site group according to the adjacent position relationship between the sites associated with the point coordinators may have various implementation manners, and the following four implementation manners are exemplified in the embodiment of the present invention.

In a first implementation manner, the stations in the same group are grouped according to the signal-to-noise ratio between the stations, so that the stations in the same group can be detected mutually, and specifically, signal-to-noise ratio information is obtained, wherein the signal-to-noise ratio information comprises the signal-to-noise ratio measured by each station associated with the point coordinator; and dividing the sites associated with the point coordinator into at least one site group according to the signal-to-noise ratio information, wherein the signal-to-noise ratio between any two sites in each site group is not less than a preset signal-to-noise ratio threshold value.

Optionally, the method for acquiring signal-to-noise ratio information includes: and receiving measurement information sent by each station associated with the point coordinator, wherein the measurement information of any station comprises the signal-to-noise ratio measured by any station and other stations, and the other stations are the stations except any station in the stations associated with the point coordinator.

In a second implementation manner, the sites associated with the point coordinators are divided into at least one site group according to the distance between each site and the point coordinators, and specifically, the geographic positions of the sites associated with the point coordinators are obtained; determining the distance between each site in the sites associated with the point coordinators and the point coordinators according to the geographic positions of the sites associated with the point coordinators; and dividing the sites associated with the point coordinators into at least one site group according to the distance between each site and the point coordinators, wherein the distance between any one site in each site group and the point coordinators is within the distance range corresponding to the site group.

In a third implementation manner, the point coordinator may divide the sites associated with the point coordinator into at least one site group according to a preset sector division rule, and specifically, divide the sites associated with the point coordinator into at least one sector according to the preset sector division rule; and determining the site in each sector as the site in one site group.

In a fourth implementation manner, the sites associated with the point coordinator are divided into at least one site group according to a preset sector division rule, and then the division rule of the distance between each site and the point coordinator is used, specifically, the point coordinator can divide the sites associated with the point coordinator into at least one sector according to the preset sector division rule; and dividing the sites associated with the point coordinators into at least one site group according to the distance between each site in at least one sector and the point coordinators, wherein the distance between any one site in each site group and the point coordinators is within the distance range corresponding to the site group.

Optionally, before the sending the group query frame to the stations in the first station group, the method further includes: determining the target site among the sites of the first site group; and determining the data transmission sequence of each target station.

It should be noted that all stations in the first station group may be stations that need to send data, but the group query frame specifically includes which stations need to be further determined, that is, a target station is determined in the first station group; because the group inquiry frame comprises a plurality of stations, but only one station can send data to the point coordinator at the same time, the data sending sequence of each target station is determined in the group inquiry frame, so that the plurality of stations can be ensured to send data in order, and data sending conflict does not occur.

Optionally, the determining the target station among the stations of the first station group may include: determining alternative sites in the sites of the first site group, wherein the alternative sites are sites to be sent with data or all the sites in the first site group; and determining the target site in the alternative sites.

Optionally, the implementation process of the point coordinator determining the target site in the alternative sites may have a variety of implementation manners, and the following two cases are taken as examples in the embodiment of the present invention.

In a first case, the determining the target site among the alternative sites may include: determining a sending time length threshold value of each alternative station; judging whether the sum of the sending time length thresholds of all the alternative stations is smaller than the remaining time length of the current contention-free stage; when the sum of the sending time length thresholds of all the alternative stations is smaller than the remaining time length of the current contention-free stage, determining all the alternative stations as the target station; when the sum of the sending time length thresholds of all the alternative stations is not less than the remaining time length of the current contention-free stage, selecting at least one alternative station, which determines that the sum of the sending time length thresholds is less than the remaining time length of the current contention-free stage, from all the alternative stations as the target station, and taking the remaining alternative stations as alternative stations of the next contention-free stage.

It should be noted that, because each station can send the data volume to be sent and the sending rate to the point coordinator, the point coordinator can determine the station whose data volume to be sent is not 0 as the station to which data to be sent. Taking these stations as alternative stations, the data transmission of these stations can be processed preferentially.

Optionally, the determining the sending duration threshold of each candidate station includes: acquiring the data volume to be sent and the sending rate of each alternative site; determining a sending duration threshold of each alternative site according to preset fixed overhead, and the data volume to be sent and the sending rate of each alternative site;

the sending duration threshold of any optional site meets a duration calculation formula, wherein the duration calculation formula is as follows: t ═ d/v + x₁(ii) a The T is a threshold of the sending duration of any optional site, the d is the amount of data to be sent of any optional site, the v is the sending rate of any optional site, and the x is₁Is the fixed overhead.

Optionally, the selecting, as the target station, at least one candidate station that determines that the sum of the sending duration thresholds is smaller than the remaining duration of the current contention-free phase from among all the candidate stations may have various implementation manners, and the following three cases are taken as examples in the embodiment of the present invention to describe.

In a first implementation manner, the point coordinator performs descending sorting on the alternative sites according to the size of the sending time length threshold, and then selects at least one alternative site with the top sorting and the sum of the sending time length thresholds smaller than the remaining time length as a target site according to the sorting result.

In a second implementation manner, the point coordinator performs descending sorting on the alternative sites according to the data sending priority, and then selects at least one alternative site with the top sorting and the sum of sending duration thresholds smaller than the remaining duration as a target site according to the sorting result.

In a third implementation mode, the point coordinator performs descending sorting on the alternative sites according to the size of the sending time length threshold and the height of the data sending priority, and then selects at least one alternative site which is sorted in the front and has the sum of the sending time length thresholds smaller than the remaining time length as a target site according to a sorting result.

Optionally, the group inquiry frame further comprises: and the sending time length threshold of each target station.

In a second case, the set of inquiry frames further includes: the determining, by the target station in the candidate stations, the sending duration threshold of each target station includes: determining all the alternative sites as target sites; the sending time length threshold of each target station is a preset value, and the sum of the sending time length thresholds of all the target stations is smaller than the remaining time length of the current contention-free stage; or, the sending time length threshold of each target station is equal and is an average remaining time length, and the average remaining time length is a quotient of the remaining time length of the current contention-free stage and the number of the target stations.

It should be noted that the point coordinator directly determines all the sites in the first site group as the candidate sites, which can reduce the operations of the point coordinator.

Optionally, the determining the data transmission sequence of each target station includes: acquiring the data transmission priority of each target station; and determining the data transmission sequence of each target station according to the data transmission priority of each target station, wherein the data transmission priority is positively correlated with the data transmission sequence.

It should be noted that, it is an implementation manner to determine the data transmission order of each target station according to the data transmission priority of each target station.

Optionally, the data information includes: a sequence number of the received data frame; or, the data information includes: a starting sequence number and an ending sequence number of the received data.

According to the scheme disclosed by the embodiment of the invention, as the plurality of sites associated with the point coordinator are divided into at least one site group, in the process of one inquiry, the point coordinator only needs to send one inquiry frame and one confirmation frame to the plurality of sites in the site group, compared with the prior art, the method and the device for inquiring the plurality of sites can reduce the overhead generated by repeatedly sending the inquiry frames to the plurality of sites, can use links for transmission of effective data as much as possible, and improve the link utilization rate.

In a second aspect, an embodiment of the present invention provides a data transmission method, which is applied to a first station in a wireless local area network, where the first station is any station in a first station group, and the first station group is any one of at least one station group obtained by a point coordinator dividing a station associated with the point coordinator, where the method includes: receiving a group query frame sent by the point coordinator, the group query frame comprising: a station identifier of each target station and a data transmission sequence of each target station, where the target station is a station in the first station group; and when the first station is a target station in the group of inquiry frames, sending data to the point coordinator according to the data sending sequence of the first station in the group of inquiry frames.

According to the scheme of the embodiment of the invention, the group inquiry frame comprises a plurality of stations, but only one station can send data to the point coordinator at the same time, and the plurality of stations in the group inquiry frame send data to the point coordinator in sequence according to the data sending sequence in the group inquiry, so that the plurality of stations can be ensured to send data in order, and data sending conflict does not occur.

Optionally, the sending data to the point coordinator according to the sending data sequence of the first station in the group query frame includes: when the data transmission sequence of the first station is 1 and data to be transmitted exist in the first station, transmitting the data to the point coordinator at the current contention-free stage; when the data transmission sequence of the first station is k, and k is more than or equal to 2, monitoring the data transmission condition of the station before the first station by detecting whether radio waves exist in an air interface; when detecting that the first n stations of the first stations do not send data according to the group inquiry frame and that the first stations have data to be sent, sending data to the point coordinator at the time x in the current contention-free stage, where x satisfies: x is t0+ (n +1) × t1+ w, where t0 is the data transmission start time determined according to the group query frame, w is the total duration of m times of data transmission on the detected air interface, n + m is k-1, and t1 is the duration of a short interframe space SIFS.

The determination of the time when the first station transmits data to the point coordinator according to the data transmission sequence of the first station is another guarantee for ensuring the orderly data transmission.

Optionally, the group inquiry frame further comprises: the sending duration threshold of each target station, and the sending duration of the data of the first station is less than or equal to the sending duration threshold of the first station.

It should be noted that, the sending duration of the data of the first station is less than or equal to the sending duration threshold of the first station, which can ensure that the data of the first station can be sent at one time.

Optionally, before the receiving of the group query frame sent by the point coordinator, the method further comprises: measuring signal-to-noise ratios of the first site and other sites, the other sites being sites other than the any one site in the sites associated with the point coordinator; sending measurement information to the point coordinator, the measurement information including the signal-to-noise ratio.

It should be noted that the first station measures the snr of the first station with other stations, and sends the measurement information including the snr to the point coordinator, which provides a basis for the point coordinator to divide the stations associated with the first station into a plurality of station groups according to the snr.

Optionally, before the receiving of the group query frame sent by the point coordinator, the method further comprises: and sending the data volume to be sent and the sending rate of the first station to the point coordinator.

It should be noted that the first station in the first station group sends the data volume to be sent and the sending rate to the point coordinator, so that the point coordinator can uniformly manage all stations in the first station group.

In a third aspect, an embodiment of the present invention provides a data transmission device, configured to execute the data transmission method provided in the first aspect.

In a fourth aspect, an embodiment of the present invention provides a data transmission device, configured to execute the data transmission method provided in the second aspect.

The data transmission device provided in the third and fourth aspects may each include: a processor and a network interface.

A processor includes one or more processing cores. The processor executes various functional applications and data processing by executing software programs and units.

The network interface may be plural, and the network interface is used for communication with other storage devices or network devices.

Optionally, the network device further includes a memory, a bus, and the like. The memory and the network interface are respectively connected with the processor through buses.

The memory may be used for storing software programs as well as units. In particular, the memory may store an operating system, application program elements required for at least one function. The operating system may be a Real Time eXceptive (RTX) operating system, such as LINUX, UNIX, WINDOWS, or OS X. The processor is configured to execute the program code to implement the relevant steps of the first aspect or the second aspect.

The technical effects obtained by the third and fourth aspects of the embodiments of the present invention are similar to the technical effects obtained by the technical means corresponding to the first and second aspects, and are not described herein again.

In a fifth aspect, an embodiment of the present invention provides a data transmission system, including: at least one point coordinator and at least two sites associated with the point coordinator; the point coordinator comprises the data transmission apparatus of the third aspect; the station comprises the data transmission device of the fourth aspect.

The technical scheme provided by the embodiment of the invention has the following beneficial effects:

according to the data transmission method, the data transmission equipment and the data transmission system, the plurality of sites related to the point coordinator are divided into at least one site group, and in the process of inquiring once, the point coordinator only needs to send one inquiry frame and one confirmation frame to the plurality of sites in the site group. And, by determining the data transmission order of each station in the group inquiry, data transmission collision does not occur between stations.

Drawings

Fig. 1-1 is a schematic structural diagram of a data transmission system according to a data transmission method provided in an embodiment of the present invention;

fig. 1-2 are schematic structural diagrams of a data transmission system according to another data transmission method provided in an embodiment of the present invention;

fig. 1 to 3 are schematic diagrams illustrating a data transmission principle of a distributed coordination function access manner according to an embodiment of the present invention;

fig. 1 to 4 are schematic diagrams illustrating a data transmission principle of a point coordination function access manner according to an embodiment of the present invention;

fig. 1-5 are schematic diagrams illustrating a hidden node principle according to an embodiment of the present invention;

FIG. 2-1 is a flow chart of a data transmission method according to an embodiment of the present invention;

FIG. 2-2 is a schematic diagram of a point coordinator and a geographical location of a site according to an embodiment of the present invention;

FIGS. 2-3 are schematic diagrams of sector distributions of a site and a point coordinator according to an embodiment of the present invention;

FIGS. 2-4 are schematic diagrams of a point coordinator and a distribution of stations according to an embodiment of the present invention;

FIGS. 2-5 are flowcharts illustrating a method for a point coordinator to determine a target site among sites in a first site group according to an embodiment of the present invention;

fig. 2-6 are flowcharts of a method for determining a target site among alternative sites according to an embodiment of the present invention;

fig. 2-7 are schematic diagrams of a group query frame format according to an embodiment of the present invention;

FIGS. 2-8 are diagrams of alternative group query frame formats provided by embodiments of the present invention;

fig. 2-9 are schematic diagrams illustrating formats of a frame data confirmation part of group confirmation provided by an embodiment of the present invention;

fig. 2-10 are schematic diagrams illustrating formats of an acknowledgment portion of group acknowledgment frame data according to another embodiment of the present invention;

fig. 2-11 are schematic diagrams illustrating formats of a frame data confirmation part of another group confirmation provided by an embodiment of the present invention;

fig. 2-12 are schematic diagrams illustrating formats of a frame data confirmation part of another group confirmation according to an embodiment of the present invention;

fig. 3-1 is a block diagram of a data transmission device according to an embodiment of the present invention;

fig. 3-2 is a block diagram of another data transmission device according to an embodiment of the present invention;

fig. 3-3 is a block diagram of a grouping module according to an embodiment of the present invention;

FIGS. 3-4 are block diagrams of alternative packet modules provided by embodiments of the present invention;

fig. 3-5 are block diagrams of structures of another packet module provided by the embodiment of the present invention;

fig. 3 to 6 are block diagrams of structures of still another data transmission device according to an embodiment of the present invention;

3-7 are block diagrams of a first determining module according to an embodiment of the present invention;

3-8 are block diagrams of a second determining submodule provided in an embodiment of the present invention;

3-9 are block diagrams of a second determining submodule provided in an embodiment of the present invention;

fig. 4-1 is a block diagram of a data transmission apparatus according to another embodiment of the present invention;

fig. 4-2 is a block diagram of a data transmission device according to another embodiment of the present invention;

fig. 4-3 are block diagrams of still another data transmission device according to an embodiment of the present invention;

fig. 5 is a block diagram of a data transmission apparatus according to another embodiment of the present invention;

fig. 6 is a block diagram of a data transmission device according to an embodiment of the present invention.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Fig. 1-1 provides a schematic structural diagram of a data transmission system 0 according to a data transmission method provided by an embodiment of the present invention, and referring to fig. 1-1, the data transmission system includes at least one point coordinator 01 and at least two sites 02 associated with the point coordinator, each point coordinator 01 serves the at least two sites 02 associated with the point coordinator, and performs unified management on the sites associated with the point coordinator, and fig. 1-1 is drawn by taking a point coordinator as an example. The association of the station and the point coordinator means that when a data transmission system is deployed, the station inquires a preset channel list, sends an association request frame to the point coordinator meeting the conditions according to the inquiry result, and establishes an association relation with the point coordinator after the association request frame is allowed by the point coordinator.

In the data transmission system, the point coordinator may divide the stations associated with the point coordinator into at least one station group according to the adjacent position relationship between the stations associated with the point coordinator, and send a group query frame to the at least one station group, each station in the corresponding station group sequentially sends data to the point coordinator according to the data sending sequence of the stations in the group query frame, the station may send data to the point coordinator according to the sequence specified in the group query frame after receiving the group query frame sent by the point coordinator, and the point coordinator sends a group acknowledgement frame to each station in the station group after receiving the data sent to the point coordinator by each station in the station group, so as to indicate that the data sent by the station is received.

Wherein, the station can be a wireless communication chip, a wireless sensor or a wireless communication station, for example: mobile phones, tablets, set-top boxes, smart televisions, smart wearable devices, vehicle-mounted communication devices, and computers. Optionally, a station may support an 802.11ax system, and further optionally, the station may also support multiple systems such as 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11 a.

Alternatively, the point coordinator may be served by an Access Point (AP) while the point coordinator is located within the AP. The AP, also referred to as a wireless access point or a hotspot, is an access point for a mobile user to enter a wired network, and is mainly deployed in a home, a building, and a garden, and typically has a coverage radius of several tens of meters to hundreds of meters, and may be deployed outdoors. The AP is equivalent to a bridge connecting a wired network and a wireless network, and is mainly used for connecting clients of the wireless networks together and then connecting the wireless networks into the wired network. Specifically, the AP may be a station device or a network device with a Wireless Fidelity (WiFi) chip. Optionally, the AP may be a device supporting 802.11ax standard, and further optionally, the AP may be a device supporting multiple standards such as 802.11n, 802.11g, 802.11b, 802.11a, and 802.11 ac. Fig. 1-1 may be a schematic diagram of a data transmission system serving at least two stations by an AP acting as a point coordinator, for example.

Alternatively, the point coordinator 01 may be located outside the AP03, and the point coordinator 01 and a controller (controller) together serve a plurality of APs 03, and then the AP03 performs unified management on at least two stations 02. For example, a schematic structural diagram of the corresponding data transmission system 0 may be as shown in fig. 1-2, wherein the controller is not shown in the figure.

For convenience of reader understanding, the data transmission principle of the distributed coordination function access manner and the point coordination function access manner and the hidden node involved in the embodiments of the present invention are briefly introduced here.

In the data transmission process, there are two phases, namely a contention phase and a contention-free phase, where an access mode corresponding to the contention phase is a distributed coordination function access mode, and an access mode corresponding to the contention-free phase is a point coordination function access mode, which specifically includes:

fig. 1-3 show the principle of data transmission in the distributed coordination function access manner. In the access mode, data transmission is in a competition stage, each station in the data transmission system competes for using a wireless air interface, and each station randomly avoids backoff according to an index when data transmission conflicts. As shown in fig. 1-3, when STA1 performs data transmission, STA2, STA3, and STA4 all have data to transmit, after STA1 completes data transmission, after waiting for a Distributed Inter Frame Space (DIFS) that is idle in a channel, STA2, STA3, and STA4 enter a fair Contention phase, and each station randomly selects a backoff (backoff) time in a Contention Window (CW). As shown in the figure, in the first contention window, since the backoff time selected by STA3 is the shortest and the backoff timer is first decreased to 0, STA3 may start data transmission at the time when the backoff timer is decreased to 0, when the backoff timers of STA2 and STA4 are frozen (the frozen duration is shown as a filled portion in the figure). During the data transmission of STA3, STA5 also needs data transmission, which enters a waiting procedure. After STA3 finishes data transmission, wait for a distributed inter-frame interval of channel idle, unfreeze the back-off timers of STA2 and STA4, randomly select a back-off time for STA5, and then STA2, STA4, and STA5 start contention, where the contention process may refer to the contention process in the first contention window, which is not described herein again.

Please refer to fig. 1-4 for the data transmission principle of the access mode of the point coordination function. In this access scheme, data transmission is in a contention-free phase. After a duration of a point coordination function Inter frame Space (PIFS) from the beginning of the contention-free phase, if the channel is not occupied, the point coordinator sends a Beacon frame (B) to the associated stations to inform all stations of the length of the contention-free phase. After sending a Short Inter Frame Space (SIFS) duration of the beacon frame, the point coordinator polls the stations associated with the beacon frame, that is, sends inquiry frames to the stations in sequence. For example, after STA1 receives the inquiry frame, if there is Data to be transmitted, STA1 may send a Data frame (i.e., Data + CF-Poll frame in the figure) to the point coordinator, if there is no Data to be transmitted, STA1 may send a null Data frame to the point coordinator, and then the point coordinator may acknowledge the Data sent by STA1 according to the situation, i.e., send an acknowledgement frame (i.e., CF-ACK frame in the figure), and if STA1 does not receive the acknowledgement frame, STA1 may only send the Data frame when it is polled again. During this process, stations that are not polled cannot send any data frames to the point coordinator. The polling procedure of STA2 may refer to the corresponding procedure of STA1, which is not described herein. The contention-free phase ends until the point coordinator sends a contention-free End (CF-End) frame.

The calculation mode of the time length S of the distributed interframe space is as follows: S-S1 + 2S 2; the calculation mode of the time length I of the inter-frame interval of the point coordination function is as follows: i ═ S1+1 × S2.

Wherein S1 is the time length of SIFS, S2 is the time length of Slot time (Chinese: Slot length). The SIFS and Slot time durations are defined in the 802.11 standard. For example, in 802.11n (5G), the duration of SIFS is 16 microseconds, the duration of Slottime is 9 microseconds, and S is 34 microseconds and I is 25 microseconds.

Fig. 1 to 5 are schematic diagrams of a hidden node principle, and as shown in fig. 1 to 5, it is assumed that both a station a and a station C need to send data to a point coordinator B, but the station a and the station C cannot detect each other (in the figures, a dotted circle 1 and a dotted circle 2 are detection ranges of the station a and the station C, respectively), and when no other station sends data to the point coordinator B, the station a and the station C both consider that a channel at the current time is in an idle state through detection, that is, data can be sent to the station B. Because the site a and the site C cannot detect each other, if both the site a and the site C send data to the point coordinator B at this time, the data sent by the site a and the site C will collide at the point coordinator B, which finally results in data transmission failure.

Since the data transmission system includes at least one site group, each site group includes at least two sites, the embodiment of the present invention is described by taking a first site group and a first site in the first site group, where the first site group is any one site group in the at least one site group included in the data transmission system, and the first site is any one site in the at least one site group including the at least two sites included in the at least one site group, fig. 2-1 is a flowchart of a data transmission method shown according to an exemplary embodiment, and as shown in fig. 2-1, the method may include:

step 201, the point coordinator divides the sites associated with the point coordinator into at least one site group according to the adjacent position relationship between the sites associated with the point coordinator, and each site group comprises at least two adjacent sites.

Optionally, to avoid the problem of hidden nodes, the adjacent position relationship may be a position adjacent in a physical sense, or a position adjacent in a communication sense, as long as any two stations in the grouped station group can monitor each other, and the embodiment of the present invention does not specifically limit the position relationship.

Optionally, the method for the point coordinator to divide the sites associated with the point coordinator into at least one site group according to the adjacent position relationship between the sites associated with the point coordinator may have various implementation manners, and the following three implementation manners are exemplified in the embodiment of the present invention.

In a first implementation, the point coordinator may divide the sites associated with the point coordinator into at least one site group based on the signal-to-noise ratio of the first site to other sites. Illustratively, the method may comprise:

step a1, the first site measures the signal-to-noise ratio of the first site and other sites, the other sites being sites other than any one of the sites associated with the point coordinator.

The method for measuring the signal-to-noise ratio of the first station and the other stations by the first station may refer to a conventional method for measuring the signal-to-noise ratio of a station, and details thereof are not repeated herein.

By way of example, assume that the sites associated with the point coordinators are: STA1, STA2, STA3, and STA4, when the first station is STA1, STA1 measures the signal-to-noise ratio of STA1 with STA2, STA3, and STA 4.

Step b1, the point coordinator obtains the signal-to-noise ratio information, the signal-to-noise ratio information includes the signal-to-noise ratio measured by each station associated with the point coordinator.

The point coordinator obtains the signal-to-noise ratio information, that is, receives the measurement information sent by each station associated with the point coordinator, where the measurement information of any station includes the signal-to-noise ratio measured by any station with respect to other stations, and the other stations are stations other than any station in the stations associated with the point coordinator.

By way of example, assume that the sites associated with the point coordinators are: STA1, STA2, STA3, and STA4, the point coordinator obtains the snr information as: STA1 measured signal-to-noise ratio of STA1 to STA 2: signal-to-noise ratio of 20dB (Chinese: decibel), STA1 and STA 3: 30dB and signal-to-noise ratio of STA1 to STA 4: 35dB, STA2 measured signal-to-noise ratio of STA2 to STA 1: signal-to-noise ratio of 20dB, STA2 and STA 3: 32dB and signal-to-noise ratio of STA2 to STA 4: 35dB, and the signal-to-noise ratio of STA3 to STA1 as measured by STA 3: 30dB, signal-to-noise ratio of STA3 to STA 2: 32dB and signal-to-noise ratio of STA3 to STA 4: 23 dB. The point coordinator acquiring the signal-to-noise ratio information can be as shown in table 1.

TABLE 1

Alternatively, it may be assumed that any station may measure the signal-to-noise ratio of the station with itself, for example, assuming that the signal-to-noise ratios of STA1, STA2, STA3, and STA4 with itself are 50dB, at which time the point coordinator acquires the signal-to-noise ratio information as shown in table 2.

TABLE 2

	STA1	STA2	STA3	STA4
					STA1	50	20	-30	-35
STA2	20	50	-32	-35
					STA3	-30	-32	50	23
STA4	-35	-35	23	50

And step c1, the point coordinator divides the sites associated with the point coordinator into at least one site group according to the signal-to-noise ratio information, and the signal-to-noise ratio between any two sites in each site group is not less than a preset signal-to-noise ratio threshold value.

And the point coordinator divides the station related to the point coordinator into at least one station group according to the acquired signal-to-noise ratio information according to the principle that the signal-to-noise ratio between any two stations in each divided station group is not less than the preset signal-to-noise ratio threshold value, so that any two stations in the divided station group can mutually monitor each other.

Illustratively, as shown in table 1, assuming that the preset snr threshold is 20, the stations STA1, STA2, STA3 and STA4 associated with the point coordinator may be divided into two groups, i.e., STA1 and STA2 are divided into one station group, and STA3 and STA4 are divided into one station group.

It should be noted that the SNR according to the first implementation manner may be a Signal-to-Noise Ratio (SNR), which is a Ratio of the strength of the received useful Signal to the strength of the received Noise, or may be a Signal-to-Interference plus Noise Ratio (SINR), which is a Ratio of the strength of the received useful Signal to the strength of the received Interference Signal (including Noise and Interference), where the Noise refers to Noise determined by the thermal performance of a receiver used for receiving the Signal in the station and generated by the receiver itself, and the Interference refers to Interference caused by objects other than the receiver to the receiver.

In a second implementation, the point coordinator may divide the sites associated with the point coordinator into at least one site group according to the distance between the site associated with the point coordinator and the point coordinator. Illustratively, the method may comprise:

step a2, the point coordinator obtains the geographic location of the site with which the point coordinator is associated.

Alternatively, the method by which the point coordinator obtains the geographical location of the associated site may refer to conventional methods, such as: the embodiments of the present invention are not described herein in detail.

By way of example, assume that the sites associated with the point coordinators are: the geographical positions of STA1, STA2, STA3, and STA4, and the geographical positions of the point coordinators, STA1, STA2, STA3, and STA4 may be coordinate positions, as shown in fig. 2-2, the point coordinators may establish a preset coordinate system, and obtain coordinates of themselves and each station in the coordinate system, for example, the coordinates of the point coordinators are (2, 2), the coordinates of STA1 are (1, 2), the coordinates of STA2 are (1.5, 1), the coordinates of STA3 are (2, 1), and the coordinates of STA4 are (2.5, 3), which is a unit of hundred meters.

It should be noted that fig. 2-2 are only schematic examples for convenience of description, and in practical applications, the coordinate position of the station is usually defined by latitude and longitude.

And b2, the point coordinators determine the distance between each site in the sites associated with the point coordinators and the point coordinators according to the geographic positions of the sites associated with the point coordinators.

One way to determine the distance between each of the sites associated with the point coordinator and the point coordinator may be to obtain a euclidean distance, also called an euclidean metric, between the site and the point coordinator, according to the geographic location of the site associated with the point coordinator and the location of the point coordinator itself.

Illustratively, as in FIGS. 2-2, STA1 has a Euclidean distance from the point coordinator of

Similarly, the euclidean distance between STA2 and the point coordinator is 1.12, the euclidean distance between STA3 and the point coordinator is 1, and the euclidean distance between STA4 and the point coordinator is 1.12.

And c2, the point coordinators divide the sites associated with the point coordinators into at least one site group according to the distance between each site and the point coordinators, and the distance between any one site in each site group and the point coordinators is within the distance range corresponding to the site group.

Optionally, the distance range corresponding to each grouped station group may be set to be within a numerical range, for example: the distance range may be [0, 50] m, (50, 100] m, and (100, 150] m, etc., that is, all the sites whose sites are at a distance of [0, 50] m from the point coordinator are divided into a site group, all the sites whose sites are at a distance of (50, 100] m from the point coordinator are divided into a site group, and all the sites whose sites are at a distance of (100, 150] m from the point coordinator are divided into a site group, etc.

For example, as shown in FIG. 2-2, assuming that the distance ranges corresponding to the station groups are preset to be 0 ~ 1 (including 1) and 1 ~ 2 (including 2), the distances between the stations and the point coordinator calculated according to step b2 divide the 4 stations shown in the figure into two station groups, i.e., STA1 and STA3 into one station group, and STA2 and STA4 into one station group.

In a third implementation, the point coordinator may divide the sites associated with the point coordinator into at least one site group according to a preset sector division rule. Illustratively, the method may comprise:

step a3, the point coordinator divides the site associated with the point coordinator into at least one sector according to the preset sector division rule.

Optionally, the point coordinator determines an area of the point coordinator and all the sites associated with the point coordinator and the position of the point coordinator as a closed area with a certain geometric shape, and then divides the closed area into at least one area according to a preset angle by taking the position of the point coordinator as a vertex, where the at least one area is at least one sector.

For example, as shown in fig. 2-3, assuming that 11 stations are associated with a point coordinator in a certain data transmission system, which are STA1 to STA11, respectively, and the area where the 11 stations and the point coordinator are located corresponds to a circular area, the circular area may be divided into 4 areas, that is, 4 sectors, which are sector 1, sector 2, sector 3, and sector 4, respectively, according to a preset angle of 90 °.

In practical applications, the geometric shapes corresponding to the areas of the positions where all the sites associated with the point coordinator are located and the preset angles for dividing the closed areas with the geometric shapes may be selected in various ways, and the embodiment of the present invention does not specifically limit the geometric shapes.

Step b3, the point coordinator determines the sites in each sector as the sites in a site group.

Exemplarily, as shown in fig. 2-3, STA1, STA5, STA6, and STA8 are included in sector 1, STA4 and STA9 are included in sector 2, STA2, STA10, and STA11 are included in sector 3, STA3 and STA7 are included in sector 4, according to this information, a station in each sector is determined as a station in one station group, then station group 1 includes STA1, STA5, STA6, and STA8, station group 2 includes STA4 and STA9, station group 3 includes STA2, STA10, and STA11, and station group 4 includes STA3 and STA 7.

In a fourth implementation manner, the point coordinator may divide the sites associated with the point coordinator into at least one sector according to a preset sector division rule, and then divide the sites associated with the point coordinator into at least one site group according to a distance between each site in the at least one sector and the point coordinator. Illustratively, the method may comprise:

step a4, the point coordinator divides the site associated with the point coordinator into at least one sector according to the preset sector division rule.

The process of dividing the site associated with the point coordinator into at least one sector according to the preset sector division rule may refer to the process of step a3, and will not be described herein again.

For example, also assuming that 11 stations are associated with the point coordinator in a certain data transmission system, which are STA1 to STA11, respectively, and the area where the 11 stations and the point coordinator are located corresponds to a circular area, the circular area may be divided into 4 areas according to a preset angle of 90 °, that is, 4 sectors, which are sector 1, sector 2, sector 3 and sector 4, respectively, and the schematic diagram refers to fig. 2 to 3.

And b4, dividing the sites associated with the point coordinators into at least one site group according to the distance between each site in at least one sector and the point coordinators, wherein the distance between any site in each site group and the point coordinators is within the distance range corresponding to the site group.

The process of dividing the sites associated with the point coordinator into at least one site group may refer to the process of the first grouping implementation manner according to the distance between each site in the at least one sector and the point coordinator, and details are not repeated here.

Illustratively, as shown in fig. 2-4, the grouping via step a4, sector 1 includes STA1, STA5, STA6 and STA8, each of which is at a distance of 18, 13, 14 and 7 from the point coordinator; sector 2 includes STA4 and STA9, the distances between each site and the point coordinator are 15 and 8, respectively; sector 3 includes STA2, STA10, and STA11, and the distances between each site and the point coordinator are 12, 13, and 18, respectively; sector 4 includes STA3 and STA7, each located at 14 and 14 distances from the point coordinator, respectively. According to the distance between each station and the point coordinator, the stations associated with the point coordinator can be divided into 9 station groups as shown in the figure, the distance between any station in each station group and the point coordinator is within the distance range corresponding to the station group, wherein the station group (i) comprises STA8, the station group (ii) comprises STA9, the station group (iii) comprises STA5 and STA6, the station group (iv) comprises STA4, the station group (iv) comprises STA2 and STA10, the station group (iv) comprises STA3 and STA7, the station group (iv) comprises STA1, and the station group (iv) comprises STA 11.

Step 202, the first station sends the data volume to be sent and the sending rate of the first station to the point coordinator.

Before the point coordinator sends the group query frame to the first site group, the data volume of data to be sent by each site in the first site group and the sending rate of the data to be sent by each site in the first site group need to be obtained in advance, so that all sites in each site group can be managed uniformly.

For example, it is assumed that the first station group includes three stations, which are STA1, STA2, and STA3, respectively, data amounts of data to be transmitted of the stations are 5 megabits, 20 megabits, and 10 megabits, respectively, and transmission rates of STA1, STA2, and STA3 are all 100 megabits per second (Mbps). Accordingly, STA1, STA2, and STA3 may transmit the above-described data amount and transmission rate to the point coordinator.

In practical application, if some stations do not have data to be transmitted, the data volume to be transmitted and the transmission rate may not be transmitted to the point coordinator, or the data volume to be transmitted and the transmission rate may be transmitted, but both are 0.

Step 203, the point coordinator determines the target site among the sites of the first site group.

2-5, the process by which the point coordinator determines the target site among the sites of the first site group may include:

step 2031, the point coordinator determines alternative sites among the sites in the first site group, where the alternative sites are sites to send data or all sites in the first site group.

The station to which data is to be transmitted is a station which is likely to transmit data to the point coordinator, and is predicted by the point coordinator. The point coordinator is configured to coordinate data transmission of each station in the contention-free phase, and generally preferentially serve the station with the data transmission requirement, please refer to step 202, because each station can transmit the data volume to be transmitted and the transmission rate to the point coordinator, the point coordinator can determine that the station with the data volume to be transmitted being not 0 is the station with the data to be transmitted. These sites are treated as alternative sites with priority.

In practice, to reduce the operation of the point coordinator, the point coordinator may also directly determine all the sites in the first site group as candidate sites.

Step 2032, the point coordinator determines the target site among the alternative sites.

The implementation process of the point coordinator for determining the target site in the alternative sites can be implemented in various ways, and the embodiment of the present invention is described in the following two aspects.

In a first aspect, as shown in fig. 2-6, the process of determining a target site among the alternative sites may include:

step 2032a, the point coordinator determines the sending duration threshold of each candidate station.

Optionally, the group inquiry frame further comprises: a transmission duration threshold for each target station. The sending duration threshold is determined by the point coordinator according to the data volume to be sent and the sending rate sent to the point coordinator by the first station. The process of determining the transmission duration threshold of each candidate station may include:

step a1, the point coordinator obtains the data volume to be sent and the sending rate of each alternative station.

Since the point coordinator receives the amount of data to be transmitted and the transmission rate of each station in step 202, the point coordinator can extract the amount of data to be transmitted and the transmission rate of each candidate station.

Step b1, the point coordinator determines the sending duration threshold of each alternative site according to the preset fixed overhead, the data volume to be sent and the sending rate of each alternative site.

The sending time length threshold of any optional site meets a time length calculation formula, wherein the time length calculation formula is as follows:

T＝d/v+x₁；

t is a sending time length threshold of any optional site, d is a data volume to be sent of any optional site, v is a sending rate of any optional site, and x₁Is a fixed overhead.

The fixed overhead is a duration occupied by non-information bits for assisting data transmission in a data transmission process, for example, a duration occupied by a Short Training Sequence (STF) symbol, a Long Training Sequence (LTF) symbol, and a MAC Header (MAC Header).

For example, it is assumed that the first station group includes three stations, which are STA1, STA2, and STA3, data to be transmitted by each station is 5 mbit, 20 mbit, and 10 mbit, the transmission rates of STA1, STA2, and STA3 are all 100 mbit/s, the preset fixed overhead is 5 microseconds, the transmission duration threshold of STA1 is 5 mbit/100 mbit/s +5 microseconds is 55 microseconds, the transmission duration threshold of STA2 is 20 mbit/100 mbit/s +5 microseconds is 205 microseconds, and the transmission duration threshold of STA3 is 10 mbit/100 mbit/s +5 microseconds is 105 microseconds.

Step 2032b, the point coordinator determines whether the sum of the sending time length thresholds of all the candidate stations is less than the remaining time length of the current contention-free phase.

In practical application, there are two situations when the contention-free phase ends, one is that all stations in the polling list complete polling, and the other is that the remaining duration of the contention-free phase is not enough to poll the next station. Therefore, in the embodiment of the present invention, in a polling process, when the point coordinator determines a target station among the candidate stations, it needs to ensure that the sum of the transmission time thresholds of the finally determined target station is less than the remaining time of the contention-free phase, so as to ensure that data of the target stations in the first station group can be completely transmitted before the contention-free phase ends in the current data transmission process.

Step 2032c, when the sum of the sending duration thresholds of all the candidate stations is less than the remaining duration of the current contention-free phase, the point coordinator determines all the candidate stations as the target station.

Step 2032d, when the sum of the sending duration thresholds of all the candidate stations is not less than the remaining duration of the current contention-free phase, the point coordinator selects at least one candidate station, as the target station, among all the candidate stations, for which the sum of the sending duration thresholds is determined to be less than the remaining duration of the current contention-free phase, and takes the remaining candidate station as the candidate station of the next contention-free phase.

Optionally, at least one candidate station that determines that the sum of the sending time length thresholds is smaller than the remaining time length of the current contention-free phase is selected from all the candidate stations as the target station, which may have various implementation manners.

For example, assume that the candidate stations are STA1, STA2, STA3, and STA4, where the transmission duration threshold of STA1 is 55 microseconds, the transmission duration threshold of STA2 is 205 microseconds, the transmission duration threshold of STA3 is 105 microseconds, the transmission duration threshold of STA4 is 80 microseconds, and the remaining duration of the contention-free phase is 400 microseconds. The point coordinator performs descending sorting on the alternative sites according to the sending duration threshold, and the result is as follows: STA2(205 microseconds), STA3(105 microseconds), STA4(80 microseconds), and STA1(55 microseconds), since 205+105+80 is 390<400 and 205+105+80+55 is 445>400, the top three alternative stations STA2, STA3, and STA4 may be selected as target stations.

Optionally, one implementation manner of determining the data transmission priority of the first station may be: the first station sends the data volume to be sent and the sending rate of the first station to the point coordinator and sends the priority of the first station to the point coordinator; another way to implement this is: and the point coordinator inquires the corresponding relation between the preset site port and the priority according to the port information of the first site to obtain the priority information of the site. In practical application, the priority of the first station may also be determined in other manners, which is not limited in the embodiment of the present invention.

For example, suppose that the candidate stations are STA1, STA2, STA3, and STA4, where the transmission duration threshold of STA1 is 55 microseconds, the transmission duration threshold of STA2 is 205 microseconds, the transmission duration threshold of STA3 is 105 microseconds, the transmission duration threshold of STA4 is 80 microseconds, the remaining duration of the contention-free phase is 400 microseconds, and the priorities of the stations are: 2. 3, 1 and 4. The point coordinator performs descending sorting on the alternative sites according to the priority levels, and the result is as follows: STA3(105 microseconds), STA1(55 microseconds), STA2(205 microseconds), and STA4(80 microseconds), since 105+55+205 is 365<400 and 105+55+205+80 is 445>400, the top three alternative stations STA3, STA1, and STA2 may be selected as target stations.

In practical applications, a sorting result obtained by sorting the candidate stations in a descending order according to the sending duration threshold may conflict with a sorting result obtained by sorting the candidate stations in a descending order according to the data sending priority, for example: when sorting is performed according to the size of the sending duration threshold, a certain station may be at the first position in a sorting result; but a station may be at the last bit in the ranking result when ranking according to the priority. Therefore, when the point coordinator performs descending sorting on the alternative sites according to the size of the sending duration threshold and the data sending priority, weights need to be set for the two sorting results to represent the influence of the sending duration threshold and the data sending priority on the sorting results. In practical applications, the specific setting of the weight may be set according to actual situations, and the embodiment of the present invention is not particularly limited thereto.

For example, suppose that the candidate stations are STA1, STA2, STA3, and STA4, where the transmission duration threshold of STA1 is 55 microseconds, the transmission duration threshold of STA2 is 205 microseconds, the transmission duration threshold of STA3 is 105 microseconds, the transmission duration threshold of STA4 is 80 microseconds, the remaining duration of the contention-free phase is 400 microseconds, and the priorities of the stations are: 2. 3, 1 and 4, wherein 1 is the highest priority and 4 is the lowest priority. The influence of the sending duration threshold and the data sending priority on the sorting result is 0.4 and 0.6, namely the corresponding weights are 0.4 and 0.6 respectively. The STA1, STA2, STA3 and STA4 are sorted in descending order according to the size of the transmission duration threshold: 4. 1, 2 and 3; the STA1, STA2, STA3 and STA4 are sorted in descending order according to the priority of data transmission: 2. 3, 1 and 4. According to the influence of the transmission duration threshold and the data transmission priority on the sequencing result, the sequencing of the STA1, the STA2, the STA3 and the STA4 is as follows: 4 × 0.4+2 × 0.6 ═ 2.8, 1 × 0.4+3 × 0.6 ═ 2.2, 2 × 0.4+1 × 0.6 ═ 1.4, and 3 × 0.4+4 × 0.6 ═ 3.6, that is, the result of sorting the candidate stations in descending order according to the size of the transmission duration threshold and the priority of data transmission is: STA3(105 microseconds), STA2(205 microseconds), STA1(55 microseconds), and STA4(80 microseconds), since 105+205+55 is 365<400 and 105+205+55+80 is 445>400, three top ranked candidate stations, i.e., STA3, STA2, and STA1, may be selected as target stations.

In a second aspect, the group inquiry frame may further include: a transmission duration threshold for each target station. The process of determining the target site among the alternative sites may include: the point coordinator determines all candidate sites as target sites.

The sending time length threshold of each target station is a preset value, and the sum of the sending time length thresholds of all the target stations is smaller than the remaining time length of the current contention-free stage; or, the sending time length threshold of each target station is equal and is an average remaining time length, and the average remaining time length is a quotient of the remaining time length of the current contention-free stage and the number of the target stations.

In a second aspect, the point coordinator may determine all candidate stations as target stations whose transmit duration thresholds are assigned by the point coordinator. On one hand, the sending duration threshold may be randomly allocated by the point coordinator, and the random allocation manner may be various, which is not limited in the embodiment of the present invention. However, the random allocation method needs to ensure that the sum of the transmission time thresholds of all target stations is less than the remaining time of the current contention-free phase. On the other hand, the sending duration threshold of each station may not be randomly allocated, for example, the sending duration threshold of each station may be equal, and the equal sending duration threshold is an average remaining duration, that is, a quotient of the remaining duration of the current contention-free phase and the number of target stations. For example, assuming that the remaining duration of the current contention-free phase is 200 microseconds and the number of the target stations is 5, the transmission duration threshold allocated to each target station is 200/5-40 microseconds.

Step 204, the point coordinator determines the data transmission sequence of each target station.

Alternatively, the process of the point coordinator determining the order in which each target station transmits data may include:

step 2041, the point coordinator obtains the data transmission priority of each target station.

Step 2042, the point coordinator determines the data transmission sequence of each target station according to the data transmission priority of each target station, wherein the data transmission priority is positively correlated with the data transmission sequence.

The data transmission priority is positively correlated with the transmission data sequence, that is, the transmission data sequence of the station with the highest data transmission priority is 1, that is, the first transmission data, and the last transmission data of the station with the lowest data transmission priority.

For example, suppose the target stations are STA1, STA2, STA3 and STA4, and the priorities of the stations are: 2. 3, 1 and 4, the transmission data sequence of STA1, STA2, STA3 and STA4 is: 2. 3, 1 and 4.

In practical application, the point coordinator may also determine the data transmission sequence of each target station according to the time length of data transmission required by each target station. For example, the data transmission sequence of each target station may be determined according to the size of the time length for which each station needs to transmit data, where the sequence may be descending or ascending.

Step 205, the point coordinator sends a group query frame to each station in the first group of stations.

Wherein the group inquiry frame includes: the station identification of each destination station and the transmission data sequence of each destination station.

In the embodiment of the present invention, the point coordinator sending a group query frame to each site in the first site group means that the point coordinator sends a group query frame to the first site group in a multicast or broadcast message manner. Each site in the first site group can receive a group inquiry frame sent by the point coordinator by adopting a multicast or broadcast message mode. In the mode of sending the group inquiry frame, because only one group inquiry frame is sent to one site group in one data transmission process, compared with the prior art, the inquiry frame does not need to be sent to each site one by one, so that the overhead generated by sending the inquiry frame to a plurality of sites one by one is reduced, the link can be used for the transmission of effective data as much as possible, and the link utilization rate is improved.

Alternatively, the station identifier of each target station may be a MAC address corresponding to the station, and the MAC address is composed of 6 8-bit data. The station identifier may also be an Association Identifier (AID) associated between the station and the point coordinator, and the Association identifier is assigned by the point coordinator when the station and the point coordinator establish an Association relationship.

The transmission data sequence for each destination station is the transmission data sequence determined in step 204. In the group inquiry frame, the transmission data sequence of each target station is characterized by the sequence in which the station identification appears in the group inquiry frame.

For example, assume that a certain group of inquiry frames includes target stations STA1, STA2, STA3 and STA4, whose station identifications are: MAC1, MAC2, MAC3, and MAC4, the transmission data sequence of each destination station is: 1.2, 3, and 4, the format of the set of inquiry frames may be as described with reference to fig. 2-7.

Optionally, the group inquiry frame may further include: a transmission duration threshold for each target station.

For example, assume that a certain group of inquiry frames includes target stations STA1, STA2, STA3 and STA4, whose station identifications are: MAC1, MAC2, MAC3, and MAC4, the transmission data sequence of each destination station is: 1.2, 3 and 4, the sending time length threshold of each target station is respectively as follows: p1, P2, P3, and P4, the format of the set of query frames may be as shown with reference to fig. 2-8.

And step 206, when the first station is a target station in the group inquiry frame, the first station sends data to the point coordinator according to the data sending sequence of the first station in the group inquiry frame.

And when the first station is the target station in the group inquiry frame, the first station sends data to the point coordinators according to the data sending sequence of the first station in the group inquiry frame. According to different data transmission sequences of the first station, the first station transmitting data to the point coordinator can comprise the following conditions:

in the first case, when the data transmission sequence of the first station is 1 and there is data to be transmitted in the first station, the first station transmits data to the point coordinator in the current contention-free phase.

The first station sends data to the point coordinator during the current contention-free phase, i.e., the first station may send data to the point coordinator at the time when the group inquiry frame is received plus a short inter-frame interval duration. The short interframe space is a fixed duration that is consumed in preparation for data transmission.

In practical applications, the time when the first station sends data to the point coordinator may be the time when the group query frame is received plus a plurality of short interframe space durations, for example: 1.2 or 1.5, and the embodiments of the present invention are not limited herein. In the embodiment of the present invention, a data transmission method is described by taking 1 short frame interval as an example.

In the second case, when the data transmission sequence of the first station is k, and k is greater than or equal to 2, the first station monitors the data transmission condition of the station before the first station by detecting whether radio waves exist in an air interface. When detecting that the first n stations of the first station do not send data according to the group inquiry frame and the first station has data to be sent, the first station sends the data to the point coordinator at the time x in the current contention-free stage, wherein x satisfies: x is t0+ (n +1) t1+ w.

T0 is the data transmission start time determined according to the group inquiry frame, w is the total time length of m times of data transmission on the detected air interface, n + m is k-1, and t1 is the time length of the short interframe space SIFS.

The data transmission condition is an occupation condition of the station on the channel, and includes, for example, starting to occupy the channel, occupying the channel, and ending to occupy the channel.

The wireless local area network uses CSMA/CA (chinese: carrier sense multiple access/collision avoidance) to share wireless resources with all users, and in the whole data transmission system, only two communication entities can communicate at a time, and the two communication entities will occupy all channels, such as a point coordinator and a certain station. Therefore, when the transmission data sequence of the first station is k, and k ≧ 2, it needs to first detect whether the channel is occupied. When the target station in the group inquiry frame sequentially sends data to the point coordinator, whether the channel is occupied or not can be detected by monitoring the data sending condition of the station before the first station. Optionally, the data transmission of the station before the first station may be monitored by detecting whether a radio wave exists on the air interface. Illustratively, the first station may continue to detect for air-interface radio waves from the time of receipt of the group interrogation frame using techniques such as energy detection or coherent detection.

According to the group query frame, the first station may obtain a data transmission start time of a first target station (i.e., a first station that transmits data in the data sequence of 1) in the group query frame, where the data transmission start time is a time obtained by adding a short inter-frame interval duration to a time when the group query frame is received, that is, the data transmission start time t0 determined according to the group query frame. Meanwhile, the first station can detect the total duration w of m times of data transmission on the air interface (actually, the duration of m times of data transmission is detected respectively and then accumulated) through detecting the air interface radio waves. Therefore, the first station may also detect that the first n stations of the first station do not transmit data. The first n stations do not transmit data means that the point coordinator determines the station as a target station and allocates a transmission duration threshold to the target station in the group query frame, but the station does not transmit data at the time when the station correspondingly transmits data (for example, the station does not actually transmit data). The above n, m and k should satisfy the relationship: n + m ═ k-1. Assume that the duration of a short interframe space is t 1. The first station may send data to the point coordinator at time x in the current contention-free phase, where x satisfies: x is t0+ (n +1) t1+ w.

For example, when the data transmission sequence of the first station is 1, the first station may transmit data to the point coordinator in the current contention-free phase, that is, transmit data to the point coordinator at the time when the group query frame is received plus the duration of a short inter-frame interval, which may be denoted as t 0; when the data transmission sequence of the first station is 5, the data transmission start time determined according to the group query frame is t0, the total duration of 2 times of data transmission on the detected air interface is 200 microseconds, the first 2 stations of the first station do not transmit data, the duration of a short inter-frame interval is 10 microseconds, that is, k is 5, w is 200, m is 2, n is 2, and t1 is 10, the first station transmits data to the point coordinator at the time when x is t0+ (2+1) × 10+200 (t0+230) microseconds in the current contention-free phase.

It should be noted that, the time when the first station sends data to the point coordinator in the above example indicates: the first station transmitting data in the order k should follow the following rules when transmitting data: after the data of the station with the data transmission sequence of k-2 is transmitted, if the station with the data transmission sequence of k-1 has data to be transmitted, the first station can transmit the data to the point coordinator at the moment that a short inter-frame interval after the data of the station with the data transmission sequence of k-1 is transmitted is finished; and if the station with the data transmission sequence of k-1 has no data to be transmitted, the first station transmits the data to the point coordinator at the end time of two short inter-frame intervals after the data transmission of the station with the data transmission sequence of k-2 is finished. When the data transmission sequence of the first station is other values, the analogy can be performed by referring to the above description, and details are not repeated here.

The data transmission rule can ensure that the stations included in the group inquiry frame can orderly transmit data to the point coordinator without data transmission collision.

It should be noted that the transmission duration of the data of the first station is less than or equal to the transmission duration threshold of the first station, and the data that the first station transmits to the point coordinator each time may include at least one data frame.

Step 207, the point coordinator sends a group acknowledgement frame to each station in the first station group according to the received data, wherein the group acknowledgement frame includes: site identification and data information for each of the at least one targeted site.

After the point coordinator receives the data sent by the at least one target station, it may send a group acknowledgement frame to each station in the first group of stations based on the received data. The point coordinator shown in the embodiment of the present invention sends a group acknowledgement frame to each site in the first site group, which means that the point coordinator sends a group acknowledgement frame to the first site group in a multicast or broadcast message manner. And each site in the first site group can receive a group acknowledgement frame sent by the point coordinator by adopting a multicast or broadcast message mode. According to the mode for sending the group acknowledgement frame, because only one group acknowledgement frame is sent to one site group in one data transmission process, compared with the traditional technology, the acknowledgement frame does not need to be sent to each site one by one, so that the overhead generated by sending the acknowledgement frame to a plurality of sites one by one is reduced, links can be used for transmission of effective data as much as possible, and the link utilization rate is improved.

Optionally, the data information includes: a sequence number of the received data frame; alternatively, the data information includes: a starting sequence number and an ending sequence number of the received data.

Optionally, there may be various implementations of the point coordinator sending the group acknowledgement frame to each station in the first station group, and the following two examples are used to illustrate the implementation of the present invention.

In a first implementation, the point coordinator acknowledges the multiple data frames contained in the data sent by each target station one by one in a group acknowledgement frame, which may be in the format of the acknowledgement portion of the group acknowledgement frame data as shown in fig. 2-9. The PeerSTAAddress is a site identifier of the target site, and the sequence num is a sequence number of a data frame received by the point coordinator.

For example, assuming that during a certain data transmission, target stations STA1, STA2, and STA3 each send multiple data frames to the point coordinator, the station identification of STA1 is 8 AAA: BBBB: CCC 0; STA2 has a site identification of 8 AAA: BBBB: CCC 2; STA3 has a site identification of 8 AAA: BBBB: CCC 8; the sequence numbers of the data frames sent by the STA1 received by the point coordinator are: 4000. 4001 and 4002; the sequence numbers of the data frames sent by the STA2 received by the point coordinator are: 5000 and 5001; the sequence numbers of the data frames sent by the STA3 received by the point coordinator are: 6000. the point coordinator then acknowledges the multiple data frames sent by each destination station one by one, and the format of the acknowledgment portion of the set of acknowledgment frames can be as shown in fig. 2-10.

In a second implementation manner, the point coordinator acknowledges the data blocks sent by each target station in a group Acknowledgement frame, i.e. it acknowledges the data blocks in a Block Acknowledgement (Block Acknowledgement) manner, and the format of the group Acknowledgement frame data Acknowledgement part may refer to fig. 2-11, where PeerSTAAddress is the station identifier of the target station, start sequence num is the start sequence number of the data frame received by the point coordinator, and end sequence num is the end sequence number of the data frame received by the point coordinator.

In practical applications, the format of the group confirmation frame data confirmation part for confirmation one by one and confirmation in blocks may be in various forms, and the modes of confirmation in blocks and confirmation one by one may also be used in a mixed manner, which is not specifically limited in the embodiment of the present invention.

For example, assuming that during a certain data transmission, target stations STA1, STA2, and STA3 each send multiple data frames to the point coordinator, the station identification of STA1 is 8 AAA: BBBB: CCC 0; STA2 has a site identification of 8 AAA: BBBB: CCC 2; STA3 has a site identification of 8 AAA: BBBB: CCC 8; the sequence numbers of the data frames sent by the STA1 received by the point coordinator are: 4000. 4001 and 4002; the sequence numbers of the data frames sent by the STA2 received by the point coordinator are: 5000 and 5001; the data frame sequence number received by the point coordinator and sent by STA3 is: 6000. the point coordinator then uses a block acknowledgement scheme for the multiple data frames sent by each target station, and the format of the group acknowledgement frame data acknowledgement portion may be as shown in fig. 2-12.

Optionally, the group acknowledgement frame may be sent together with the CF-End frame to indicate that the contention-free phase is ended, and the data transmission enters a Distributed coordination function Access mode or an Enhanced Distributed Channel Access (EDCA) Access mode.

EDCA is an Access method corresponding to a distributed Coordination Function Access method in Hybrid Coordination Function Controlled Channel Access (HCCA), and the data transmission principle of the Access method may refer to the data transmission principle of the distributed Coordination Function, which is not described herein again.

Optionally, when the target station is determined among the stations in the first station group, it may occur that some stations in the candidate stations have more data to send, and the sum of the sending time length thresholds of all the candidate stations is greater than the remaining time length of the current contention-free phase. At this time, the current group query frame may include part or all of the stations with more data to be transmitted and part or all of the remaining stations, so that the sum of the transmission time thresholds corresponding to the stations included in the group query frame is smaller than and close to the remaining time of the current contention-free phase, the stations not included in the current group query frame are included in another group query frame, and the stations are preferentially queried in the next contention-free phase. Therefore, the problem that the station cannot use the link for a long time can be avoided, and the link utilization rate can be improved to a certain extent.

In a certain data transmission process, taking an 802.11n system and a MAC layer rate of 300Mbps as examples, in an inquiry frame, the length of a header of an 802.11 frame is 30 bytes, an effective byte of a contention-free polling frame (english: CF-Poll) is 4 bytes, an effective byte of an acknowledgement (english: ACK) frame is 8 bytes, a frame check sequence (english: FCS) is 4 bytes, 46 bytes (368 bits) are counted, and the time required for sending each inquiry frame is 368/300 microseconds (1.2 microseconds for convenience of calculation), and similarly, the overhead of the acknowledgement frame is also 1.2 microseconds. In the 802.11n high-speed mode, the short frame interval is 16 microseconds, the overhead of transmitting one frame in the data transmission system is 36 microseconds, and the basic overhead of transmitting the frame is 36+ 16-52 microseconds. The data transmission system has 10 stations, and the data frame overhead of each station is 40 microseconds, wherein 8 stations have data to transmit, that is, the time for data transmission is 40 × 8 — 320 microseconds. In PCF or HCCA, 10 inquiry frames and 10 acknowledgement frames are required to be sent, and the time to complete the data transmission is: 20 × 52+20 × 1.2+8 × 40 — 1384 microseconds, and link utilization 320/1384 × 100% — 23.12%. In the embodiment of the present invention, 10 stations are divided into 1 group, and only one inquiry frame and one acknowledgement frame need to be sent, then the time for completing the data transmission is: 2+ 1.2+8 + 40-426.4 microseconds, link utilization 320/426.4-75.05%. Therefore, the data transmission method provided by the embodiment of the invention effectively improves the link utilization rate.

Collision avoidance in a wireless local area Network is achieved through a lifetime (english: Duration) field in a frame header of 802.11, where the field is used to indicate time taken to transmit a current frame (including transmission of an ACK frame), and after receiving the frame, a station in a data transmission system updates its own Network Allocation Vector (NAV) according to the Duration field, and before the NAV is finished, the corresponding station does not perform data transmission, thereby achieving collision avoidance in data transmission.

It should be noted that, the order of the steps of the method for acquiring a network policy provided in the embodiment of the present invention may be appropriately adjusted, and the steps may also be increased or decreased according to the circumstances, and any method that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application shall be included in the protection scope of the present application, and therefore, no further description is given.

In summary, in the data transmission method provided in the embodiment of the present invention, because the plurality of sites associated with the point coordinator are divided into at least one site group, in one query process, the point coordinator only needs to send one query frame and one acknowledgement frame to the plurality of sites in the site group, compared with the conventional technology, overhead generated by repeatedly sending query frames to the plurality of sites can be reduced, links can be used for transmission of valid data as much as possible, the link utilization rate is improved, and meanwhile, the load of the point coordinator is reduced. And, by determining the data transmission order of each station in the group inquiry, data transmission collision does not occur between stations.

Fig. 3-1 is a block diagram illustrating a structure of a data transmission apparatus 300 according to an exemplary embodiment, the data transmission apparatus 300 being applied to a point coordinator in a wireless local area network, and as shown in fig. 3-1, the data transmission apparatus 300 may include:

a first sending module 301, configured to send a group inquiry frame to each station in a first station group, where the group inquiry frame includes: the station identification of each target station and the data sending sequence of each target station, the first station group is any one of at least one station group obtained by dividing the stations associated with the point coordinator by the point coordinator, and the target station is the station in the first station group.

A receiving module 302, configured to receive data sent by at least one target station according to a data sending sequence.

A second sending module 303, configured to send a group acknowledgement frame to each station in the first station group according to the received data, where the group acknowledgement frame includes: site identification and data information for each of the at least one targeted site.

In summary, in the data transmission device provided in the embodiment of the present invention, the grouping module divides the multiple sites associated with the point coordinator into at least one site group, and in a query process, the first sending module only needs to send one query frame to the multiple sites in the site group, and the second sending module only needs to send one acknowledgement frame to the multiple sites in the site group.

As shown in fig. 3-2, the data transmission device 300 may further include:

and the grouping module 304 is configured to divide the sites associated with the point coordinators into at least one site group according to the adjacent position relationship between the sites associated with the point coordinators, where each site group includes at least two adjacent sites.

As shown in fig. 3-3, the grouping module 304 includes:

the first obtaining sub-module 3041 is configured to obtain the signal-to-noise ratio information, where the signal-to-noise ratio information includes a signal-to-noise ratio measured by each station associated with the point coordinator.

The first grouping submodule 3042 is configured to divide the sites associated with the point coordinator into at least one site group according to the snr information, where an snr between any two sites in each site group is not less than a preset snr threshold.

Optionally, the first obtaining submodule 3041 is specifically configured to:

and receiving the measurement information sent by each station associated with the point coordinator, wherein the measurement information of any station comprises the signal-to-noise ratio measured by any station and other stations, and the other stations are the stations except any station in the stations associated with the point coordinator.

As shown in fig. 3-4, the grouping module 304 includes:

a second obtaining submodule 3043 for obtaining the geographical position of the site associated with the point coordinator.

A first determining submodule 3044 for determining the distance between each of the sites associated with the point coordinator and the point coordinator according to the geographical location of the site associated with the point coordinator.

And a second grouping sub-module 3045, configured to divide the sites associated with the point coordinators into at least one site group according to the distance between each site and the point coordinator, where the distance between any one site in each site group and the point coordinator is within the distance range corresponding to the site group.

As shown in fig. 3-5, the grouping module 304 includes:

a third grouping submodule 3046, configured to divide the site associated with the point coordinator into at least one sector according to a preset sector division rule.

A second determining submodule 3047, configured to determine the sites in each sector as the sites in a site group.

Optionally, as shown in fig. 3 to 6, the data transmission device 300 may further include:

a first determining module 305 for determining a target site among the sites of the first site group.

A second determining module 306, configured to determine a data transmission sequence of each target station.

Alternatively, as shown in fig. 3-7, the first determining module 305 may include:

the third determining submodule 3051 is configured to determine, among the sites in the first site group, an alternative site, where the alternative site is a site to be sent with data or all sites in the first site group.

A fourth determining sub-module 3052, configured to determine the target site among the candidate sites.

Optionally, as shown in fig. 3-8, the fourth determination sub-module 3052 may include:

the threshold determination submodule 3052a is configured to determine a transmission duration threshold of each candidate station.

The determining submodule 3052b is configured to determine whether the sum of the sending duration thresholds of all the candidate stations is smaller than the remaining duration of the current contention-free phase.

The first station determining sub-module 3052c is configured to determine, when the sum of the sending duration thresholds of all candidate stations is smaller than the remaining duration of the current contention-free phase, all candidate stations as a target station.

The processing sub-module 3052d is configured to, when the sum of the sending duration thresholds of all the candidate stations is not less than the remaining duration of the current contention-free phase, select, as a target station, at least one candidate station, of all the candidate stations, for which the sum of the sending duration thresholds is determined to be less than the remaining duration of the current contention-free phase, and use the remaining candidate stations as candidate stations of a next contention-free phase.

Optionally, the threshold determination sub-module 3052a is configured to:

and acquiring the data volume to be sent and the sending rate of each alternative station.

Determining a sending time length threshold of each alternative site according to preset fixed overhead, and the data volume to be sent and the sending rate of each alternative site;

T＝d/v+x₁；

Optionally, the processing sub-module 3052d is configured to:

sorting the alternative sites in a descending order according to the size of the sending time length threshold; and/or sorting the alternative sites in a descending order according to the data sending priority; and selecting at least one alternative station which is ranked in the front and the sum of the sending time length thresholds is less than the remaining time length as a target station according to the ranking result.

Optionally, the group inquiry frame further comprises: a transmission duration threshold for each target station.

Optionally, as shown in fig. 3-9, the fourth determination sub-module 3052, comprising:

a second site determination sub-module 3052e, configured to determine all candidate sites as target sites.

The sending time length threshold of each target station is a preset value, and the sending time length thresholds of all the target stations are smaller than the remaining time length of the current contention-free stage; or, the sending time length threshold of each target station is equal and is an average remaining time length, and the average remaining time length is a quotient of the remaining time length of the current contention-free stage and the number of the target stations.

Optionally, the second determining module 306 is configured to:

and acquiring the data transmission priority of each target station.

And determining the data transmission sequence of each target station according to the data transmission priority of each target station, wherein the data transmission priority is positively correlated with the data transmission sequence.

In summary, in the data transmission device provided in the embodiment of the present invention, the grouping module divides the multiple sites associated with the point coordinator into at least one site group, and in one query process, the first sending module only needs to send one query frame to the multiple sites in the site group, and the second sending module only needs to send one acknowledgement frame to the multiple sites in the site group. And, the data transmission order of each station is determined in the group inquiry by the second determination module so that data transmission collision does not occur between stations.

Fig. 4-1 is a block diagram illustrating a data transmission apparatus 400 according to an exemplary embodiment, where the data transmission apparatus 400 is applied to a first station in a wireless local area network, the first station is any station in a first station group, and the first station group is any one of at least one station group obtained by a point coordinator dividing a station associated with the point coordinator, and as shown in fig. 4-1, the data transmission apparatus 400 may include:

a receiving module 401, configured to receive a group query frame sent by a point coordinator, where the group query frame includes: and the station identification of each target station and the data transmission sequence of each target station, wherein the target station is a station in the first station group.

A first sending module 402, configured to send data to the point coordinator according to the sending data sequence of the first station in the group query frame when the first station is the target station in the group query frame.

In summary, in the data transmission device provided in the embodiment of the present invention, the receiving module receives the group query frame sent by the point coordinator, and the first sending module sends data to the point coordinator according to the sending data sequence of the first station in the group query frame, so that data sending between stations is performed in order, and no data sending collision occurs.

Optionally, a first sending module 402, configured to:

and when the data transmission sequence of the first station is 1 and the first station has data to be transmitted, transmitting the data to the point coordinator at the current contention-free stage.

When the data transmission sequence of the first station is k, and k is larger than or equal to 2, monitoring the data transmission condition of the station before the first station by detecting whether radio waves exist in an air interface.

When detecting that the first n sites of the first site do not send data and the first site has data to send according to the group inquiry frame, sending the data to the point coordinator at the time x in the current contention-free stage, wherein x satisfies: x is t0+ (n +1) t1+ w,

Optionally, the group inquiry frame further comprises: and the sending time length threshold of each target station, wherein the sending time length of the data of the first station is less than or equal to the sending time length threshold of the first station.

Optionally, as shown in fig. 4-2, the data transmission device 400 may further include:

and a measuring module 403, configured to measure a signal-to-noise ratio between the first station and other stations, where the other stations are stations other than any station in the stations associated with the point coordinator.

A second sending module 404, configured to send measurement information to the point coordinator, where the measurement information includes a signal-to-noise ratio.

Optionally, as shown in fig. 4-3, the data transmission device 400 may further include:

a third sending module 405, configured to send the data amount to be sent and the sending rate of the first station to the point coordinator.

It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described devices, modules and sub-modules may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

Referring to fig. 5, which shows a schematic structural diagram of a data transmission device 20 according to an exemplary embodiment of the present application, the data transmission device 20 may include: a processor 22 and a network interface 24.

Processor 22 includes one or more processing cores. The processor 22 executes various functional applications and data processing by executing software programs and modules.

The network interface 24 may be plural, and the network interface 24 is used for communication with other storage devices or network devices.

Optionally, the data transfer device 20 further includes a memory 26, a bus 28, and the like. Wherein the memory 26 and the network interface 24 are connected to the processor 22 via a bus 28, respectively.

Memory 26 may be used to store software programs and modules. In particular, memory 26 may store an operating system 262 and application program modules 264 required for at least one function. Operating system 262 may be a Real Time eXecutive (RTX) operating system, such as LINUX, UNIX, WINDOWS, or OS X.

The application module 264 may include:

the first transmission unit 2641 has the same or similar functions as the first transmission module 301.

The receiving unit 2642 has the same or similar functions as the receiving module 302.

The second transmitting unit 2643 has the same or similar functions as the second transmitting module 303.

Referring to fig. 6, which shows a schematic structural diagram of a data transmission device 30 according to an exemplary embodiment of the present application, the data transmission device 30 may include: a processor 32 and a network interface 34.

Processor 32 includes one or more processing cores. The processor 32 executes various functional applications and data processing by executing software programs and modules.

The network interface 34 may be multiple, the network interface 34 being used to communicate with other storage devices or network devices.

Optionally, the data transfer device 30 further includes a memory 36, a bus 38, and the like. Wherein the memory 36 and the network interface 34 are connected to the processor 32 via a bus 38, respectively.

The memory 36 may be used to store software programs and modules. In particular, memory 36 may store an operating system 362 and application modules 364 required for at least one function. Operating system 362 may be a Real Time eXceptive (RTX) operating system, such as LINUX, UNIX, WINDOWS, or OS X.

The application module 364 may include:

a receiving unit 3641 having the same or similar function as the first transmitting module 402.

The first transmitting unit 3642 has the same or similar function as the receiving module 401.

An embodiment of the present invention provides a data transmission system, including: the data transmission system includes at least one point coordinator and at least two stations associated with the point coordinator, the point coordinator including the above-described data transmission apparatus 300.

An embodiment of the present invention provides a data transmission system, including: the data transmission system includes at least one point coordinator and at least two stations associated with the point coordinator, the stations including the above-described data transmission apparatus 400.

An embodiment of the present invention provides a data transmission system, including: the data transmission system comprises at least one point coordinator and at least two stations associated with the point coordinator, the point coordinator comprising the data transmission device 20 and the stations comprising the data transmission device 30.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, where the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A data transmission method applied to a point coordinator in a wireless local area network, the method comprising:

sending a group inquiry frame to each station in a first group of stations, the group inquiry frame comprising: the first site group is any one of at least one site group obtained by dividing the sites associated with the point coordinator by the point coordinator, and the target sites are determined in the sites of the first site group;

receiving data sent by at least one target station according to the data sending sequence;

sending a group acknowledgement frame to each station in the first station group according to the received data, including: in a group acknowledgement frame, a plurality of data frames contained in data sent by each target station are acknowledged one by one and/or confirmed in blocks, wherein the group acknowledgement frame comprises: site identification and data information for each of the at least one target site;

wherein the step of determining the target site among the sites of the first site group comprises:

determining alternative sites in the sites of the first site group, wherein the alternative sites are sites to be sent with data or all the sites in the first site group; determining the target site in the alternative sites;

wherein the determining the target site among the alternative sites comprises:

determining a sending time length threshold value of each alternative station; judging whether the sum of the sending time length thresholds of all the alternative stations is smaller than the remaining time length of the current contention-free stage; when the sum of the sending time length thresholds of all the alternative stations is smaller than the remaining time length of the current contention-free stage, determining all the alternative stations as the target station; when the sum of the sending time length thresholds of all the alternative stations is not less than the remaining time length of the current contention-free stage, selecting at least one alternative station, which determines that the sum of the sending time length thresholds is less than the remaining time length of the current contention-free stage, from all the alternative stations as the target station, and taking the remaining alternative stations as alternative stations of the next contention-free stage; alternatively, the first and second electrodes may be,

determining all the alternative sites as target sites; the sending time length threshold of each target station is a preset value, and the sum of the sending time length thresholds of all the target stations is smaller than the remaining time length of the current contention-free stage; or, the sending time length threshold of each target station is equal and is an average remaining time length, and the average remaining time length is a quotient of the remaining time length of the current contention-free stage and the number of the target stations;

the method for the target station to send data according to the data sending sequence comprises the following steps:

when the data transmission sequence of the target station is 1 and data to be transmitted exist in the target station, transmitting the data to the point coordinator at the current contention-free stage;

when the data transmission sequence of the target station is k and k is larger than or equal to 2, monitoring the data transmission condition of the station in front of the target station by detecting whether radio waves exist in an air interface or not;

when detecting that the first n sites of the target sites do not send data and the target sites have data to be sent according to the group inquiry frame, sending data to the point coordinator at the moment x in the current contention-free stage, wherein x satisfies: x is t0+ (n +1) t1+ w,

t0 is the data transmission start time determined according to the group inquiry frame, w is the total duration of m times of data transmission on the detected air interface, n + m is k-1, and t1 is the duration of a short inter-frame space SIFS.

2. The method of claim 1, wherein prior to said sending a group query frame to stations in the first group of stations, the method further comprises:

and dividing the sites associated with the point coordinators into at least one site group according to the adjacent position relationship between the sites associated with the point coordinators, wherein each site group comprises at least two adjacent sites.

3. The method of claim 2,

the dividing the sites associated with the point coordinators into at least one site group according to the adjacent position relationship between the sites associated with the point coordinators includes:

acquiring signal-to-noise ratio information, wherein the signal-to-noise ratio information comprises a signal-to-noise ratio measured by each station associated with the point coordinator;

and dividing the sites associated with the point coordinator into at least one site group according to the signal-to-noise ratio information, wherein the signal-to-noise ratio between any two sites in each site group is not less than a preset signal-to-noise ratio threshold value.

4. The method of claim 3,

the acquiring signal-to-noise ratio information includes:

and receiving measurement information sent by each station associated with the point coordinator, wherein the measurement information of any station comprises the signal-to-noise ratio measured by any station and other stations, and the other stations are the stations except any station in the stations associated with the point coordinator.

5. The method of claim 2, wherein said dividing the sites associated with the point coordinators into at least one site group according to the neighboring location relationship between the sites associated with the point coordinators comprises:

acquiring the geographic position of a site associated with the point coordinator;

determining the distance between each site in the sites associated with the point coordinators and the point coordinators according to the geographic positions of the sites associated with the point coordinators;

and dividing the sites associated with the point coordinators into at least one site group according to the distance between each site and the point coordinators, wherein the distance between any one site in each site group and the point coordinators is within the distance range corresponding to the site group.

6. The method of claim 2, wherein said dividing the sites associated with the point coordinators into at least one site group according to the neighboring location relationship between the sites associated with the point coordinators comprises:

dividing the sites associated with the point coordinator into at least one sector according to a preset sector division rule;

and determining the site in each sector as the site in one site group.

7. A method according to any one of claims 1 to 6, wherein prior to said step of sending a group inquiry frame to stations in a first group of stations and after said step of determining said target station among the stations in said first group of stations, the method further comprises:

and determining the data transmission sequence of each target station.

8. The method of claim 1,

the determining the sending duration threshold of each candidate station includes:

acquiring the data volume to be sent and the sending rate of each alternative site;

determining a sending duration threshold of each alternative site according to preset fixed overhead, and the data volume to be sent and the sending rate of each alternative site;

the sending duration threshold of any optional site meets a duration calculation formula, wherein the duration calculation formula is as follows:

T＝d/v+x₁；

the T is a threshold of the sending duration of any optional site, the d is the amount of data to be sent of any optional site, the v is the sending rate of any optional site, and the x is₁Is the fixed overhead.

9. The method according to claim 1, wherein the selecting, as the target station, at least one candidate station that determines that a sum of the transmission duration thresholds is smaller than a remaining duration of a current contention-free period among all the candidate stations comprises:

sorting the alternative sites in a descending order according to the size of the sending duration threshold; and/or the presence of a gas in the gas,

sorting the alternative sites in a descending order according to the data sending priority;

and selecting at least one alternative station which is ranked in the front and the sum of the sending time length thresholds is less than the remaining time length as a target station according to the ranking result.

10. The method of claim 8,

the group inquiry frame further includes: and the sending time length threshold of each target station.

11. The method of claim 7,

the determining the data transmission sequence of each target station includes:

acquiring the data transmission priority of each target station;

12. The method of claim 1,

the data information includes: a sequence number of the received data frame; or, the data information includes: a starting sequence number and an ending sequence number of the received data.

13. A data transmission method applied to a first station in a wireless local area network, where the first station is any station in a first station group, and the first station group is any one of at least one station group obtained by a point coordinator dividing a station associated with the point coordinator, and the method includes:

receiving a group query frame sent by the point coordinator, the group query frame comprising: a site identifier of each target site, a transmission data sequence of each target site, and a transmission duration threshold of each target site, where the target site is determined by the point coordinator in the sites of the first site group,

when the first station is a target station in the group of inquiry frames, sending data to the point coordinator according to the data sending sequence of the first station in the group of inquiry frames, and the point coordinator performing confirmation and/or block confirmation on a plurality of data frames contained in the data sent by each target station in a group confirmation frame one by one;

wherein the step of the point coordinator determining the target site among the sites of the first site group comprises:

wherein the determining the target site among the alternative sites comprises:

wherein the sending data to the point coordinator according to the sending data sequence of the first station in the group of inquiry frames comprises:

when the data transmission sequence of the first station is 1 and data to be transmitted exist in the first station, transmitting the data to the point coordinator at the current contention-free stage;

when the data transmission sequence of the first station is k, and k is more than or equal to 2, monitoring the data transmission condition of the station before the first station by detecting whether radio waves exist in an air interface;

when detecting that the first n stations of the first stations do not send data according to the group inquiry frame and that the first stations have data to be sent, sending data to the point coordinator at the time x in the current contention-free stage, where x satisfies: x is t0+ (n +1) t1+ w,

14. The method of claim 13, wherein a transmission duration of the data of the first station is less than or equal to a transmission duration threshold of the first station.

15. The method of claim 13, wherein prior to receiving a group query frame sent by a point coordinator, the method further comprises:

measuring signal-to-noise ratios of the first site and other sites, the other sites being sites other than the any one site in the sites associated with the point coordinator;

sending measurement information to the point coordinator, the measurement information including the signal-to-noise ratio.

16. The method of claim 13, wherein prior to receiving a group query frame sent by a point coordinator, the method further comprises:

and sending the data volume to be sent and the sending rate of the first station to the point coordinator.

17. A data transmission apparatus, for use in a point coordinator in a wireless local area network, the apparatus comprising:

a first sending module, configured to send a group query frame to each station in a first station group, where the group query frame includes: the first site group is any one of at least one site group obtained by dividing the sites associated with the point coordinator by the point coordinator, and the target sites are determined in the sites of the first site group;

a receiving module, configured to receive data sent by at least one target station according to the data sending sequence;

a second sending module, configured to send a group acknowledgement frame to each station in the first station group according to the received data, where the group acknowledgement frame includes: site identification and data information for each of the at least one target site;

wherein the sending a group acknowledgement frame to each station in the first station group according to the received data comprises: confirming and/or blocking confirming a plurality of data frames contained in the data sent by each target station one by one in a group confirmation frame;

a first determination module comprising:

a third determining submodule, configured to determine an alternative site in the sites of the first site group, where the alternative site is a site to which data is to be sent or all sites in the first site group;

a fourth determining submodule, configured to determine the target site in the candidate sites;

the fourth determination submodule includes:

the threshold value determining submodule is used for determining the sending time length threshold value of each alternative site;

the judging submodule is used for judging whether the sum of the sending time length thresholds of all the alternative sites is smaller than the remaining time length of the current contention-free stage;

a first station determining submodule, configured to determine all candidate stations as the target station when a sum of sending duration thresholds of all the candidate stations is smaller than a remaining duration of a current contention-free stage;

the processing submodule is used for selecting at least one alternative station with the sum of the sending time length thresholds smaller than the remaining time length of the current contention-free stage from all the alternative stations as the target station and taking the remaining alternative stations as the alternative stations of the next contention-free stage when the sum of the sending time length thresholds of all the alternative stations is not smaller than the remaining time length of the current contention-free stage; or;

the second site determination submodule is used for determining all the alternative sites as target sites;

the sending time length threshold of each target station is a preset value, and the sum of the sending time length thresholds of all the target stations is smaller than the remaining time length of the current contention-free stage; or, the sending time length threshold of each target station is equal and is an average remaining time length, and the average remaining time length is a quotient of the remaining time length of the current contention-free stage and the number of the target stations;

the second sending module is configured to:

18. The apparatus of claim 17, further comprising:

and the grouping module is used for dividing the sites associated with the point coordinators into at least one site group according to the adjacent position relation between the sites associated with the point coordinators, wherein each site group comprises at least two adjacent sites.

19. The apparatus of claim 18,

the grouping module comprises:

the first acquisition submodule is used for acquiring signal-to-noise ratio information, and the signal-to-noise ratio information comprises a signal-to-noise ratio measured by each station associated with the point coordinator;

and the first grouping submodule is used for dividing the sites associated with the point coordinator into at least one site group according to the signal-to-noise ratio information, wherein the signal-to-noise ratio between any two sites in each site group is not less than a preset signal-to-noise ratio threshold value.

20. The apparatus of claim 19,

the first obtaining sub-module is configured to:

21. The apparatus of claim 18, wherein the grouping module comprises:

the second acquisition submodule is used for acquiring the geographic position of the site associated with the point coordinator;

the first determining submodule is used for determining the distance between each site in the sites associated with the point coordinator and the point coordinator according to the geographic position of the site associated with the point coordinator;

and the second grouping submodule is used for dividing the sites associated with the point coordinators into at least one site group according to the distance between each site and the point coordinators, wherein the distance between any one site in each site group and the point coordinators is within the distance range corresponding to the site group.

22. The apparatus of claim 18, wherein the grouping module comprises:

the third grouping submodule is used for dividing the sites associated with the point coordinator into at least one sector according to a preset sector division rule;

and the second determining submodule is used for determining the site in each sector as the site in one site group.

23. The apparatus of any of claims 17 to 22, further comprising:

and the second determining module is used for determining the data transmission sequence of each target station.

24. The apparatus of claim 17,

the threshold determination submodule is configured to:

T＝d/v+x₁；

25. The apparatus of claim 17, wherein the processing sub-module is configured to:

26. The apparatus of claim 24,

27. The apparatus of claim 23,

the second determining module is configured to:

acquiring the data transmission priority of each target station;

28. The apparatus of claim 17,

29. A data transmission apparatus, which is applied to a first station in a wireless local area network, where the first station is any station in a first station group, and the first station group is any one of at least one station group obtained by a point coordinator dividing a station associated with the point coordinator, and the apparatus includes:

a receiving module, configured to receive a group query frame sent by the point coordinator, where the group query frame includes: the station identification of each target station, the sending data sequence of each target station and the sending time length threshold of each target station are determined by the point coordinator in the stations of the first station group;

a first sending module, configured to send data to the point coordinator according to a sending data sequence of the first station in the group query frame when the first station is a target station in the group query frame, where the point coordinator performs one-by-one acknowledgement and/or block acknowledgement on multiple data frames included in the data sent by each target station in a group acknowledgement frame;

wherein the determining the target site among the alternative sites comprises:

the sending module is configured to:

30. The apparatus of claim 29, wherein the transmission duration of the data by the first station is less than or equal to the transmission duration threshold of the first station.

31. The apparatus of claim 29, further comprising:

a measuring module, configured to measure signal-to-noise ratios of the first station and other stations, where the other stations are stations other than the any station in the stations associated with the point coordinator;

and the second sending module is used for sending measurement information to the point coordinator, wherein the measurement information comprises the signal-to-noise ratio.

32. The apparatus of claim 29, further comprising:

and the third sending module is used for sending the data volume to be sent and the sending rate of the first station to the point coordinator.

33. A data transmission system, characterized in that the data transmission system comprises: at least one point coordinator and at least two sites associated with the point coordinator;

the point coordinator comprising the data transmission apparatus of any one of claims 17 to 28;

each of said stations comprising a data transmission arrangement according to any one of claims 29 to 32.