WO2018107370A1

WO2018107370A1 - Point to multi-point channel allocation method, apparatus, and system

Info

Publication number: WO2018107370A1
Application number: PCT/CN2016/109720
Authority: WO
Inventors: 何孝月; 孙方林; 吕捷; 陈维熙
Original assignee: 华为技术有限公司
Priority date: 2016-12-13
Filing date: 2016-12-13
Publication date: 2018-06-21
Also published as: CN109644502A; CN109644502B

Abstract

A point to multi-point channel allocation method, apparatus, and system. The method comprises: an access point configures for a station a time slot number to allow the station to start occupying a channel for data transmission, and sends same to the station; after monitoring that the channel is in an idle state, the station competes with other stations for the channel and, when successfully competing for the channel, determines whether the current time slot is the time slot corresponding to the time slot number to allow the station to start transmitting data; if the current time slot is the time slot to allow the station to start transmitting data, then occupying the channel in the time slot in order to transmit data to the access point; and if not, then waiting to reach the time slot corresponding to the time slot number to allow the channel to start transmitting data, and then occupying the channel in order to transmit data to the access point. The present method, whilst not affecting transmission efficiency, reduces the conflict that occurs when multiple stations occupy the same channel to transmit data.

Description

Point-to-multipoint channel allocation method, device and system

Technical field

The present invention relates to the field of wireless communications, and in particular, to a point-to-multipoint channel allocation method, apparatus, and system.

Background technique

WLAN (Wireless Local Area Networks) based on the IEEE 802.11 standard has been widely used in homes, office environments, airports, and bus stations to provide users with network access services. As people's demand for information increases, higher requirements are placed on the network data transmission rate. The physical layer rate of the WLAN has gradually increased from the initial 2 Mbps to 11 Mbps to 54 Mbps. Today, more than 100 Mbps of WLAN is also in use.

At present, the MAC layer work based on the 802.11 standard mainly focuses on how to improve the throughput and delay performance of the network. The standard of the 802.11-based wireless network channel access control method mainly includes PCF (Point coordination Function) and DCF (Distributed Coordination Function). Due to the relatively simple implementation of DCF, DCF is supported by most current vendors.

Based on the CSMA/CA (carrier sense multiple access with collision avoidance) mechanism and the binary exponential backoff mechanism, the DCF allows the terminal to perform channel contention after the listening channel is idle, so as to achieve the same access. Different sites of the point compete for the same channel to transmit data to the access point through carrier sense multiple access with collision avoidance. As shown in Figure 1, the channel is initially used by Station A. When Site A completes the transmission, Sites B, C, and D hear the time channel that is over DIFS idle. Therefore, the channel is determined to be idle. , respectively, to generate a backoff delay duration (as shown in Figure 1, 12 time slots, 6 time slots and 8 time slots respectively), and then start counting down. Since the backoff time generated by the station C is the smallest (6 time slots), the station C first counts down to zero, and preferentially acquires the channel usage right for data transmission. After Site C starts data transmission, Site B and Site D are heard because of the channel being Occupied, so the countdown is suspended, and the remaining duration is 6 slots and 2 slots, respectively. After the data transmission of the site C is completed, the station B and the site D detect that the time channel exceeding the DIFS (Distributed Inter-frame Spacing) is idle, and the countdown continues. After 2 time slots, station D starts data transmission, and station B hears that the channel is occupied, and pauses the countdown again.

The backoff delay duration of each station is randomly selected from the contention window (0 to CW), and there is a possibility that the random backoff time of multiple sites is the same, resulting in data transmission conflict. If the competition window is small, the probability of collision is large; if the competition window is large, although the probability of collision is reduced, the delay of data transmission is large, and the transmission efficiency is reduced.

How to balance conflict avoidance and ensure efficiency has become an urgent problem to be solved.

Summary of the invention

The embodiment of the invention provides a point-to-multipoint channel allocation method, device and system, which can reduce the situation in which multiple stations occupy the same channel to transmit data without affecting the transmission efficiency.

In a first aspect, a point-to-multipoint channel allocation method is provided in the embodiment of the present invention. The method may be applied to a scenario where multiple sites access an access point, including:

After the first station monitors that the channel is in an idle state, it contends with other stations, wherein the other stations are one or more stations other than the first station that access the access point; when successfully competing for the channel, the first station A station determines the current time slot. If it is determined that the current time slot is a time slot corresponding to the time slot number that allows the first station to start data transmission, the first station occupies the channel to the access point for data transmission in the current time slot. Otherwise, when the time slot corresponding to the slot number that allows the first station to start data transmission arrives, the occupied channel performs data transmission to the access point. The above channel is a channel used by a plurality of sites accessing the access point to compete for use.

In the above method, the first station starts data transmission only on the time slot corresponding to the slot number that is allowed to start data transmission, so as to reduce the occurrence of data transmission failure caused by multiple stations occupying channel transmission data at the same time.

In conjunction with the first aspect, in a first possible implementation of the first aspect, the foregoing allows the first The slot number at which the station starts data transmission is sent by the access point to the first station. The access point will send the slot number of the first station to start data transmission to the first station, so that the access point can access the data of the access station according to the number of stations accessing the access point, the service performed by the station. Transmission is regulated.

With reference to the first aspect and the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the first site is assigned a site group after accessing the access point, and the same The stations in the site group are configured with the same slot number that allows data transmission to begin. The first station receives the broadcast message sent by the access point, and the broadcast message includes the correspondence between the identifier of the site group and the slot number that allows the station in the site group to start data transmission. The first station may determine the slot number that allows the first station to start data transmission according to the identifier of the site group in which it is located and the corresponding relationship.

According to the statistics of the frequency of data transmission to the station, it is found that configuring a set of stations with the same slot number that allows data transmission to start does not significantly increase the probability of data transmission collision, and considering the limited number of time slots, When it is applied to a public place such as an office environment or an airport, and the number of visited sites is large, the accessed sites can be grouped, and the same slot number that allows data transmission to be started is configured for a group of sites. Improve the utilization of time slots, thereby improving the data transmission efficiency of the system.

With reference to the first aspect and the second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the site group may be prioritized according to the priority of the data transmission by the site, and the priority is high. The number of slot numbers in which the stations in the site group are allowed to start data transmission is greater than or equal to the number of slot numbers in the station group in which the priority group is allowed to start data transmission.

In some application scenarios, data transmission priorities of different sites may be different, and sites with higher priority may be grouped into one group; or service types of data transmission may have different priorities, and services may be transmitted according to site data. The priority of the type, which dynamically updates the site grouping. In order to ensure that the sites in the higher priority site group can transmit data in time and reduce the data transmission conflicts at these sites, you can assign a larger number of sites to the higher priority site groups. The slot number is assigned to the lower priority station group by a smaller number of slot numbers to reduce the delay and data transmission conflicts of the higher priority stations during data transmission.

In conjunction with the first aspect and the first possible implementation of the first aspect, in a fourth possible implementation of the first aspect, the group of sites may be partitioned according to the AID of the site. When the visited site does not have a prioritization, or the service type of the transmitted data does not have a prioritization, the site grouping can be performed according to the AID of the site, and the operation is simple and easy to implement.

With reference to the first aspect, in a fifth possible implementation manner of the first aspect, when the first station needs to perform data transmission and the station monitors that the channel is in an idle state, the first station may receive multiple preset delays. A backoff delay duration is selected from the duration, and a countdown is started. When the countdown is cleared, the first station determines whether the current time slot is a time slot that allows the first station to start data transmission. If it is a time slot that allows the first station to start data transmission, the first station occupies the channel to start data transmission; otherwise, when the first station waits for the time slot corresponding to the time slot number that is allowed to start data transmission to arrive, the occupied channel is performed. data transmission. If the channel is occupied during the waiting period, the first station waits for the channel to be idle again and allows the time slot corresponding to the slot number at which the first station starts data transmission to arrive, and the occupied channel starts data transmission.

By selecting a backoff delay duration for each site, it is possible to further reduce the possibility of collisions between multiple sites for data transmission. For example, multiple stations that can start data transmission using time slots corresponding to the same time slot number need to perform data transmission at the same time, and simultaneously monitor that the channel is in an idle state, a collision occurs; and each station selects a backoff delay duration. When the backoff delay is different, collisions are avoided.

Specifically, the first station may randomly select a backoff delay duration from a preset plurality of delay durations; or may select a priority according to the priority of the first station for data transmission, for example, a site with a higher priority is selected. A short backoff delay duration is preferred, while a lower priority site selects a longer backoff delay duration.

With reference to the first aspect, in a sixth possible implementation manner of the first aspect, when the first station monitors whether the channel is idle or not, the first station considers that the channel is in the idle state, and the channel is considered to be the channel. Available. The first station reaches the preset when it detects that the channel is idle. After the duration, data transmission is performed, so that there is a certain interval between the two data transmissions, so that the access points can be distinguished.

A second aspect of the present invention provides a point-to-multipoint channel allocation method, which is applied to a scenario where multiple sites access an access point, including:

The access point determines, for the accessed first station, a slot number that allows it to start data transmission, and then sends the determined slot number to the first station, so that the first station needs to perform data transmission and listens to After the channel is in an idle state, it contends with other stations for the channel. After successfully competing for the channel, when the time slot corresponding to the slot number that is allowed to start data transmission arrives, the occupied channel starts to transmit data to the access point. The other station is one or more stations other than the first station that access the access point, and the channel is a channel that is used by multiple sites accessing the access point to compete for use.

In the above method, the access point transmits to the first station a slot number that allows the first station to start data transmission, so that the first station starts data transmission on a time slot corresponding to the slot number that allows data transmission to start. Reducing the failure of multiple sites to simultaneously occupy channel transmission data causes data transmission to fail.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the access point may first group the first station when determining the slot number that allows the first station to start data transmission, and then The site group configuration allows the station in the site group to start the slot number for data transmission. The access point sends the correspondence between the identifier of the site group and the slot number of the site in the site group to start the data transmission by the broadcast message to the first site, so that the first site determines that it is allowed to start data transmission. Gap number.

With reference to the second aspect and the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, when the access point groups the sites, the data transmission priority may be performed according to the site. Divide, and configure a larger number of slots in the site group with higher priority to allow data transmission to start, and configure a smaller number of sites in the site group with lower priority to allow data transmission to start. Gap number.

In conjunction with the second aspect and the first possible implementation of the second aspect, in a third possible implementation of the second aspect, the group of sites may be divided according to the AID of the site. When access The site does not have a prioritization, or the service type of the transmitted data does not have a prioritization. The site can be grouped according to the AID of the site, which is simple and easy to implement.

In a third aspect, a site provided by an embodiment of the present invention is applied to a scenario where multiple sites access to an access point, where the site serves as a first site, and the first site includes:

The monitoring module is configured to monitor whether the channel is in an idle state.

The competition module is configured to compete with the other station for the channel after the listening module monitors that the channel is in an idle state; the other station is one or more stations other than the first station that access the access point.

And a determining module, configured to determine, when the channel is successfully contending to the channel, whether the current time slot is a time slot corresponding to a time slot number that allows the first station to start data transmission.

a transmission module, configured to: if the determining module determines that the current time slot is a time slot corresponding to a time slot number that allows the first station to start data transmission, occupying the channel to the access point in the current time slot Data transmission is performed; otherwise, when the time slot corresponding to the slot number that allows the first station to start data transmission arrives, the channel is occupied to perform data transmission to the access point.

The channel is a channel used by a plurality of sites accessing the access point to compete for use.

In conjunction with the third aspect, in a first possible implementation manner of the third aspect, the time slot number that allows the first station to start data transmission is sent by the access point to the first site.

With reference to the third aspect, in a second possible implementation manner of the third aspect, the first station further includes: a receiving module, configured to: receive a broadcast message sent by the access point, where the broadcast message includes a site The correspondence between the identity of the group and the slot number that allows the site in the site group to start data transmission. The first station may use the corresponding slot number in the corresponding relationship of the identifier of the site group in which it is located as the slot number that allows the first station to start data transmission.

With reference to the third aspect, and the second possible implementation manner of the third aspect, in a third possible implementation manner of the third aspect, the site group is prioritized according to a priority of data transmission by the station, and the priority is high. The number of slot numbers in which the stations in the site group are allowed to start data transmission is greater than or equal to the number of slot numbers in the station group in which the priority group is allowed to start data transmission.

With reference to the third aspect and the second possible implementation manner of the third aspect, in a fourth possible implementation manner of the third aspect, the site group is divided according to a value of the association identifier AID of the site.

With reference to the third aspect, in a fifth possible implementation manner of the third aspect, the contention module is specifically configured to: determine a backoff delay duration, where the backoff delay duration is within a preset multiple delay duration The selected backoff delay duration; when the duration of the channel idle state reaches the backoff delay duration, the first station successfully contends to the channel.

With reference to the third aspect, in a sixth possible implementation manner of the third aspect, the monitoring module, when the listening channel is in an idle state, is configured to: when the duration of the channel is idle is reached, the preset duration is It is determined that the channel is in an idle state.

In a fourth aspect, an access point provided by the embodiment of the present invention is applied to a scenario where multiple sites access to an access point, including:

And a determining module, configured to determine a slot number of the first station that allows access to the access point to start data transmission.

a sending module, configured to send the determined time slot number to the first station, so that the first station contends with other stations after listening to the channel being in an idle state, and after successfully competing for the channel, When the time slot corresponding to the slot number that is allowed to start data transmission arrives, the channel is occupied to start data transmission to the access point; the other station is the first to access the access point except the first One or more other sites outside the site.

With reference to the fourth aspect, in a first possible implementation manner of the fourth aspect, the determining module is configured to: group a site that accesses the access point; and assign a site group to each site group The slot number in which the station in the station starts data transmission.

The foregoing sending module is specifically configured to: send a broadcast message, where the broadcast message includes a correspondence between an identifier of the site group and a slot number that allows the station in the site group to start data transmission.

With reference to the fourth aspect, and the first possible implementation manner of the fourth aspect, in the second possible implementation manner of the fourth aspect, the site group is prioritized according to the data transmission of the station The number of slot numbers in which the stations in the high priority station group are allowed to start data transmission is greater than or equal to the number of slot numbers in the station group in which the priority group is allowed to start data transmission.

In a fifth aspect, the embodiment of the present invention provides a point-to-multipoint system, including an access point according to the fourth aspect, and N stations according to the third aspect, where N is greater than 1. Integer.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below.

1 is a schematic diagram of data transmission in a prior art site complying with a CSMA/CA mechanism;

2 is a schematic diagram of data transmission conflicts occurring in the prior art;

3 is a schematic diagram of a WLAN network architecture adapted to a point-to-multipoint channel allocation method according to an embodiment of the present invention;

4 is a schematic diagram of a time slot according to an embodiment of the present invention;

FIG. 5 is a schematic flowchart of a point-to-multipoint channel allocation method according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a specific embodiment according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of another specific embodiment according to an embodiment of the present disclosure;

FIG. 8 is a schematic structural diagram of a station according to an embodiment of the present disclosure;

FIG. 9 is a schematic structural diagram of another station according to an embodiment of the present disclosure;

FIG. 10 is a schematic structural diagram of an access point according to an embodiment of the present disclosure;

FIG. 11 is a schematic structural diagram of another access point according to an embodiment of the present invention.

detailed description

In order to make the objects, technical solutions and advantages of the present invention more comprehensible, the present invention will be further described in detail with reference to the accompanying drawings.

Each site transmits to the access point following the CSMA/CA mechanism in the 802.11 WLAN protocol. When data is still available, there may still be a possibility of data transfer conflicts, as shown in Figure 2. At the beginning, the channel is occupied by the site A for data transmission, and the site B, the site C, the site D, and the site E all have data to be transmitted. When the site A data transmission is completed, the other sites monitor the channel idle time to reach the DIFS duration, then the site B. Site C, Site D, and Site E each randomly select a backoff delay duration from the contention window, which is 12 slots, 2 slots, 8 slots, and 8 slots, respectively, and starts counting down. Normally, the initial contention window is [0, 15] (unit: time slot). Since the backoff delay time of station C is the shortest, station C first counts down to zero, so station C occupies the channel and starts data transmission. After Site C starts data transmission, Site B, Site D, and Site E listen to the channel being occupied and pause the countdown. At this time, Site B, Site D, and Site E have 10 time slots and 6 slots for the backoff delay. Time slot, 6 time slots. After the data transmission of the station C is finished, the time when the station B, the station D, and the station E are listening to the idle channel reaches the DIFS duration, and the countdown continues. Since the remaining backoff delays of the station D and the station E are the same, and the countdown is cleared, the countdown is cleared. Site D and Site E simultaneously transmit data, conflicts, and the access point cannot receive data normally. Site D and Site E do not receive the Receive Success Response message sent by the access point within a preset time, or receive a data transmission confirmation message (Acknowledgment) sent by the access point, but the message indicates that the data transmission fails, then Site D And station E doubles the contention window to [0, 31], and reselects a backoff delay from the new contention window, as shown in the figure, 20 time slots and 28 time slots, respectively. Restart the countdown. Since station B only has 4 slots remaining, station B first counts down and occupies the channel for data transmission. Site D and Site E pause the countdown after listening to the channel being occupied. At this time, there are 16 slots and 24 slots remaining respectively. After the data transmission of the station B is completed, the station D and the station E monitor the time when the channel idle time reaches the DIFS duration, and continue to count down. The remaining time slots of the station D are less, and the countdown is cleared first, so the station D occupies the channel for data transmission. After the transmission of the station D ends, the station E occupies the channel for data transmission.

In the prior art, after successfully transmitting data, the site D and the site E can also restore the contention window to a previously smaller contention window; if the site D or the site E continuously collides, the contention window can be expanded again to expand the window. It is 2 ^m times the original, where m is the number of consecutive collisions. Usually, the maximum size of a contention window is set, and when the contention window is expanded to the maximum, the window is no longer enlarged.

It can be seen that the choice of the contention window will affect the performance of the system transmission. If the contention window is too small, the backoff delays of multiple sites may be randomly selected, which may result in data transmission conflicts. If the contention window is too large, unnecessary delays may occur, which may affect transmission efficiency, especially in the network. Under high load conditions, the QoS (Quality of Service) requirements of sites with high requirements on transmission rate or delay cannot be met.

In order to solve the above problem, the embodiment of the present invention provides a point-to-multipoint channel allocation method, which is used to reduce the situation in which multiple stations occupy the same channel to transmit data without affecting the transmission efficiency. The method is applicable to a WLAN network architecture as shown in FIG. 3, the WLAN network architecture including an access point (AP) and a station (STA). The access point may be a device with WLAN access function, such as an optical network terminal (ONT), a coaxial cable modem (Cable Modem), a digital subscriber line modem (DSL Modem) or a router (Router), etc.; Mobile phones, tablets, wireless Internet laptops or other devices that can access the wireless network via WLAN.

The access point periodically sends a Beacon frame to the station within the range of the access point to notify each station of the existence of the access point, so that the station establishes a connection with the access point according to the information in the Beacon frame. The access point can divide the time between two Beacon frames into multiple time slots of equal duration and number each time slot, as shown in FIG. The duration of each time slot and how many time slots are shared can be controlled by the access point. The access point may notify the division principle of each station time slot through a Beacon frame or other broadcast message.

In addition, the access point may notify the station by using a reserved bit in the Operating Mode Field subfield in the Operating Mode Notification field in the Beacon frame, whether to provide a point-to-multipoint channel in the embodiment of the present invention when performing data transmission. Distribution method.

The Operating Mode Field subfield consists of a total of 8 bytes, as shown in Table 1.

Table 1

The access point can notify the station whether to apply the point-to-multipoint channel allocation method provided by the embodiment of the present invention by using the reserved bits B2 and B3. For example, if the value of B2 and B3 is 01, it indicates that the channel allocation method provided by the embodiment of the present invention is applied.

FIG. 5 is a schematic flowchart of a point-to-multipoint channel allocation method according to an embodiment of the present invention. As shown in the figure, the method specifically includes the following steps:

Step 501: The access point determines a slot number of the first station that allows access to the access point to start occupying a channel for data transmission.

The channel is a channel used by a plurality of sites accessing the access point to compete for use, for example, by using carrier sense multiple access with collision avoidance. Therefore, in order to reduce the occurrence of transmission failure caused by multiple stations occupying channel transmission data at the same time, the access point configures each access station with a slot number that allows it to start occupying the channel for data transmission, so that the station is allowed in it. Data transmission begins on the time slot corresponding to the slot number that begins to occupy the channel for data transmission.

In addition, the "first site" is used here to distinguish it from other sites accessing the access point, and does not specifically refer to a certain site.

Specifically, the access point may configure a time slot number for allowing the data transmission to start when the first site accesses the access point.

In some embodiments, the access point may group the sites accessing the access point and configure the group of stations with a slot number that allows data transmission to begin, that is, a site can only use the site group where the site is located. The data transmission starts on the time slot corresponding to the corresponding slot number, and cannot occupy the time slot corresponding to the slot number corresponding to the other group.

The data transmission frequency of the station is analyzed in advance, and the result shows that the same time slot number of the same set of sites is allowed to start data transmission, and the probability of data transmission conflict is not significantly increased. Considering that the number of time slots is limited, in a public place such as an office environment or an airport, if there are a large number of visited sites, the accessed sites can be grouped and the same permission can be configured for a group of sites. The time slot number of the data transmission is performed to improve the utilization of the time slot, thereby improving the data transmission efficiency of the system.

Optionally, when grouping sites, you can group sites in the following ways:

1) Group according to the site's AID (Association Identifier)

An access point can access a large number of sites. Therefore, the access point can assign an AID to each site to distinguish the sites. In the AID Table of the access point, each AID and its corresponding site The MAC address corresponds to facilitate the access point to manage a large number of sites. The AID value ranges from 0 to 2007. AID=0 is a reserved field and is not assigned to the site to represent multicast and broadcast. Therefore, the AID that can be assigned to the site is 1 to 2007.

The access point can group the sites according to the parity of the AID, that is, the sites with the odd AIDs are grouped into one group, and the sites with the even AIDs are grouped into one group.

When the number of sites accessed is large, the access point can also divide the site into multiple site groups according to the AID. For example, if the sites to be accessed are divided into 4 groups, the sites with (AID mod 4)=0 can be grouped into one group, and the sites with (AID mod 4)=1 can be grouped into one group (AID mod 4). The sites with =2 are grouped into groups, and the sites with (AID mod 4) = 3 are grouped.

The access point can also group the sites whose AIDs are within a certain range. For example, the sites with AIDs belonging to [1, 10] are grouped into one group, and the AIDs are grouped into other sites. It should be understood that the above numerical values are merely examples, and the specific ranges may also be other numerical ranges or non-continuous values.

Of course, the access point groups the sites according to other methods according to the AID, and the examples are not exemplified herein.

When there is no prioritization between the many sites that are accessed, or when there is no priority of the service type of the data transmission, the sites are grouped according to the AID, and the operation is simple and easy to implement.

2) Group according to the priority of data transmission by the site

In some scenarios, there may be different sites that have different requirements for the rate of data transmission, some The site has higher requirements for the transmission rate, and some sites do not have too high a requirement for the transmission rate. At this time, the access point can group the sites that need a higher transmission rate into a group, that is, a high-priority site group. Sites that have no additional requirements for transmission rate are grouped into groups of low priority sites.

In some scenarios, different sites have different priorities for data transmission. For example, IoT devices need to automatically report measurement data, which can be set to high priority; while phones or tablets that are typically used for entertainment can be set to low priority. The access point can group the stations with high priority of data transmission into one group, and divide the stations with low priority of data transmission into one group.

In other scenarios, because different data transmission service types have different priorities, sites that need to perform data transmission of high priority service types can be grouped. For example, the video service can be set to a high priority, and other services are set to a low priority. Based on this, a site that needs to perform video data transmission can be divided into a high priority site group, and a site that performs other types of data transmission is divided into Low priority site group. Since the same site may need to perform data transmission of a low priority service type after performing high priority service type data transmission, the group information of the site needs to be dynamically updated.

Of course, the packet information can also be updated in other packet modes, for example, when there is a new site access, the packet can be re-grouped or the newly accessed site can be classified into an existing site group. In addition, in addition to the above-mentioned grouping manner, the access point may also group the stations in other manners, which is not limited in this embodiment of the present invention.

Optionally, when the access point configures the slot number for different site groups to allow data transmission to start, it can be configured in the following manner:

1) Configure according to the site's AID

If the sites are grouped, the sites with the AID odd number are grouped into one group, and the sites with the even AID are grouped into one group, then the access point can allocate the time slots with the odd slot number to the sites with the odd AID. For a group, a time slot with an even slot number is assigned to a site group with an even AID.

If the station is grouped, the station is divided into M groups according to the remainder of the AID divided by M, then the access point can be divided into M groups according to the slot number divided by M, and allocated to the corresponding station. group. Still taking the site into 4 groups as an example, you can set the slot number of (Slot Number mod 2)=0. Assigned to the site group (AID mod 4) = 0, the slot number of (Slot Number mod 2) = 1 is assigned to the station group of (AID mod 4) = 1, and the time of (Slot Number mod 2) = 2 The slot number is assigned to the station group (AID mod 4) = 2, and the slot number of (Slot Number mod 2) = 3 is assigned to the station group of (AID mod 4) = 3, where Slot Number represents the slot number.

If the stations are grouped, the stations whose AIDs are within a certain range are grouped, and the access point can allocate time slots in the specific range for the group of stations. For example, if the sites with AIDs belonging to [1, 10] are grouped, the time slots with slot number [1, 10] can be assigned to the group of stations, and other slot numbers can be assigned to other stations. It should be understood that the above numerical values are merely examples, and the specific ranges may also be other numerical ranges or non-continuous values.

Of course, the access point can also configure the station group to enable the data transmission to start the data transmission according to the AID according to other methods.

2) Configure according to the priority of data transmission at the site

The access point can configure more time slot numbers for the site group with higher demand for the transmission rate, and configure fewer time slot numbers for the site group with lower transmission rate requirements to ensure higher transmission rate. The site has a shorter time delay for data transmission and can perform data transmission faster.

As described above, if the data transmission priorities of the sites in different site groups are different, you can configure more time slot numbers for the higher priority site groups, and configure the site groups with lower priority. A small number of slot numbers to ensure that stations in a higher priority group can prioritize data transmission and reduce the possibility of collisions when data is transmitted in stations in a higher priority group.

Of course, in addition to the foregoing configuration method, the access point may configure the time slot number for the different site groups to start the data transmission in other manners, which is not limited by the embodiment of the present invention.

Step 502: The access point sends the determined time slot number to the first station.

When the foregoing steps are specifically implemented, the access point may directly send the time slot number that allows the first station to start data transmission to the site; or, if the access point groups the accessed sites, and for each group of sites The slot number configured to allow data transmission to be started is configured, and the access point may send the identifier of the site group where the first site is located to the first site when the first site accesses, and identify the site group identifier and the station by using a broadcast message. The stations in the group allow the corresponding number of slot numbers to start data transmission. It is sent to the site accessing the access point to reduce the signaling resources used.

Optionally, the access point may identify the site group where the site is located by using a reserved field in the existing message.

For example, when a site initiates an association request (Association Request) to the access point, the access point returns an association response message (Association Response) to the site, and the Association Response includes an AID field for notifying the site of its corresponding AID. Generally, when an access point allocates an AID to a site, it is assigned to the site one by one according to the order of site access.

The AID field includes 16 bits, wherein bits B0 to B13 are used to indicate the AID of the station, and the highest two bits B14 and B15 are reserved bits, which are set to 1 in the prior art. Therefore, the access point can use the highest two bits B14 and B15 in the AID field to send the identity of the site group in which the site is located to the site. For example, if the site is divided into four groups according to the AID, if B14 and B15 are 00, it means that the site group where the site is located has the identifier 0, that is, the site group (AID mod 4)=0; if B14 and B15 If it is 01, it means that the site group ID of the site is 1, that is, the site group (AID mod 4)=1; if B14 and B15 are 10, it means that the site group ID of the site is 2, that is ( A group of AID mod 4)=2; if B14 and B15 are 11, it means that the site group where the site is located has the identifier of 3, that is, the site group (AID mod 4)=3.

Of course, the access point may also send the identifier of the site group where the site is located to the site through other reserved bits in the existing message; or the access point may add some fields to the existing message to locate the site where the site is located. The identity of the group is sent to the site; or, the access point can also add a new message to send the identity of the site group where the site is located to the site.

Optionally, the access point may add some fields to the existing message to send a correspondence between the site group identifier and the slot number of the station in the site group to start data transmission.

For example, an AID Group Assignment Information field may be added to the Beacon frame, and the field may contain sub-fields as shown in Table 2 to notify the site of the identity of the site group where the site is located.

Table 2

For another example, the access point may add a Slot Group Assignment field in the Beacon frame, that is, a correspondence between the site group group information and the station group identifier and the slot number that allows data transmission to start, and the subfield included in the field. As shown in Table 3, the correspondence between the site group identity and the slot number that is allowed to start data transmission can be sent to the site.

table 3

For another example, you can also add a Slot to the Beacon frame after grouping the station and the slot number. The Group Assignment Information field, which contains sub-fields as shown in Table 4, to send the correspondence between the site group and the time slot group to the site.

Table 4

According to the correspondence between the site group and the time slot group shown in Table 4, the site is divided into two types according to the parity of the AID, and the first two bits of the third byte in the above table can be defined as 00. A station indicating that the AID is an even number. When the bit is 01, the station representing the AID is an odd number; the last two bits of the third byte are defined as 00, indicating that the slot number is even, and the bit is 01. Indicates a slot group whose slot number is an odd number. If the first 4 bits of the third byte are 0101, the station in the station group indicating that the AID is odd is allowed to start data transmission using the time slot in the slot group whose odd slot number is odd.

Step 503: The first station receives a time slot number sent by the access point to allow the first station to start data transmission.

If the access point directly transmits the slot number that allows the first station to start data transmission to the first station, the first station can directly obtain the slot number that allows the data transmission to start. If the access point groups the sites, the first site is based on the identifier of the received site group of the first site, and the identifier of the site group and the slot number of the site in the allowed site group for data transmission. Corresponding relationship, determining the slot number that allows the first station to start data transmission.

Step 504: When the first station needs to perform data transmission, and the channel is monitored to be in an idle state, the first station competes with other stations for a channel. The other site is one or more sites other than the first site that access the access point.

After the first station needs to perform data transmission, it needs to first monitor whether the channel is occupied. When the channel is occupied by other stations, the first station cannot perform data transmission, and it is necessary to wait until the channel is in an idle state before competing for the channel to perform data again. transmission.

Generally, there is a certain time interval between two data transmissions, and the first station can perform data transmission after listening to the channel being idle for a preset period of time, that is, the channel is idle for a preset duration. When the channel is considered to be idle. The preset duration can be the duration of a DIFS.

In some embodiments, after the first station monitors that the channel is in an idle state, it may first select a backoff delay duration from the contention window, and start counting down. When the backoff delay time arrives, that is, when the timer is cleared, That is, the first site successfully competes for the channel. If the backoff delay time arrives before the channel is occupied by other stations, the first station pauses the timer and waits for the channel to be idle again, continuing the countdown.

As described above, the size of the contention window is set in advance, and the station can randomly select a backoff delay duration from the contention window. Of course, it can also be selected according to certain rules. For example, a station with a higher priority selects a shorter backoff delay. The time length is long, and the lower priority station selects a longer backoff delay duration, which is not limited in this embodiment of the present invention. When a data transmission conflict occurs, the contention window can be expanded, and when the data transmission is successful, the size of the contention window can be restored to the initial size.

Since the first station selects a backoff delay duration after listening to the channel being in an idle state, even if the station that is allocated to the same station group to use the same time slot for data transmission needs to perform data transmission at the same time, according to the selected backoff delay The length of time is determined, and the order of data transmission is determined to further reduce the possibility of data transmission conflicts.

Step 505: When the first station successfully contends to the channel, determine whether the current time slot is a time slot corresponding to a time slot number that allows the first station to start data transmission. If yes, go to step 506; Then, go to step 507.

As described above, the first station acquires, from the access point, a slot number that allows the first station to start data transmission, and the first station determines whether to allow data transmission to start on the current time slot based on the slot numbers.

Step 506: If the first station determines that the current time slot is a time slot corresponding to the time slot number that allows the first station to start data transmission, the first station uses the channel in the current time slot to perform data transmission to the access point.

Step 507: If the first station determines that the current time slot is not the time slot corresponding to the time slot number that allows the first station to start data transmission, the first station waits for the time slot corresponding to the time slot number that allows the first station to start data transmission. Upon arrival, the occupied channel immediately performs data transmission.

In some embodiments, the first station also needs to monitor whether the channel is idle during the waiting period. If the first station listens to other stations occupying the channel for data transmission during the waiting period, the first station still needs to wait for the end of the data transmission of the other station. Thereafter, when the channel idle time reaches a preset duration, and the time slot that allows the first station to start data transmission comes, the occupied channel starts data transmission.

In other embodiments, the first station may not listen to the channel during the waiting period, and when the time slot for allowing the first station to start data transmission arrives, the re-listening channel is in an idle state, and if the channel is in an idle state, The first station occupies the channel for data transmission, otherwise the first station still needs to wait, and when the channel is in an idle state and the time slot for allowing the first station to perform data transmission arrives, the occupied channel starts data transmission.

In the above embodiment of the present invention, the access point configures, for the first station, a slot number that allows the first station to start occupying the channel for data transmission, so that the first station corresponds to the slot number that is allowed to start data transmission. The data transmission starts on the slot, and the situation that multiple stations simultaneously occupy the channel transmission data causes the data transmission to fail. In addition, the stations accessing the access point may be grouped, for example, according to the priority of data transmission by the station, and the same time slot number for allowing a group to start data transmission is configured for a group of sites, further realizing It affects the transmission efficiency and reduces the conflict when multiple sites occupy the same channel to transmit data.

For a clearer understanding of the point-to-multipoint channel allocation method provided by the embodiment of the present invention, the following The description will be made with specific examples.

Embodiment 1.

The access point groups the sites according to the parity of the AID of the site, that is, the sites with the odd AID are grouped, and the sites with the even AID are grouped. The access point is configured with a slot with an odd slot number in the site group with an odd number of AIDs, that is, a station with an odd AID is allowed to occupy the channel for data in the slot corresponding to the slot number with an odd slot number. Transmission; the access point is a time slot with a shorter slot number for the station in the site group with an even AID, that is, the station with an even AID is allowed to occupy the channel on the time slot corresponding to the slot number with the even slot number. Data transfer.

The access point broadcasts the above-mentioned site grouping information and the available slot number configured for each station group to all stations through the Beacon frame, so that each station can obtain its own available slot number.

The access point can also set the period of the Beacon frame to 100ms, and set the Slot time of one slot to the minimum slot duration of 9us, that is, divide a Beacon frame period into 11112 slots, which can be represented by 14 bits. A time slot number. The access point may send the division rule of the above time slot to all stations by using a broadcast message.

Site 1 (STA1) has an AID of 1, and Site 2 (STA2) has an AID of 2. As shown in Figure 6, STA1 and STA2 need to perform data transmission at the same time at T1. After listening to the idle time of the channel to reach the DIFS duration (assuming the duration of the DIFS is 2 slots), a random backoff is randomly selected from the contention window. The delay time is 5 time slots and 3 time slots, and the timer is turned on to count down. Because STA2's backoff delay is shorter, the countdown is cleared first, and the slot number corresponding to the current slot is 5. Since STA2 is only allowed to start data transmission on the slot with the even slot number, STA2 cannot When data transmission starts, it needs to wait. When the time slot with slot number 6 arrives, STA2 hears that the channel is still idle. Therefore, STA2 occupies the channel on the time slot corresponding to slot number 6 to start data transmission. At this time, STA1 monitors that the channel is occupied, so STA1 pauses the countdown, and the timer has one slot remaining. After STA2 data transmission ends, STA1 monitors the channel idle time to reach the DIFS duration, and continues to count down. After 1 slot, the timer is cleared, the current slot number is 13, and STA1 is allowed to start at the current slot. Data transmission, so STA1 begins to occupy the channel for data transmission.

STA1 and STA2 need to perform data transmission again at time T2. After listening to the idle time of the channel, the length of the backoff delay is selected from the contention window, which is 4 time slots and 8 time slots respectively. The timer counts down. Since the backoff delay of STA1 is short, the countdown is cleared first, and the slot number corresponding to the current slot is 6. Since STA1 is only allowed to start data transmission on the slot with an odd slot number, STA1 cannot When data transmission starts, it needs to wait. When the time slot with slot number 7 arrives, STA1 hears that the channel is still idle. Therefore, STA1 occupies the channel on the time slot corresponding to slot number 7 to start data transmission. At this time, STA2 monitors that the channel is occupied, so STA2 pauses the countdown, and the timer has 3 slots remaining. After STA1 data transmission ends, STA2 monitors the channel idle duration to reach the DIFS duration, continues counting down, clears the timer after 3 slots, the slot number of the current slot is 16, and STA2 is allowed to start at the current slot. Data transmission, so STA2 begins to occupy the channel for data transmission.

Example 2

The access point can also divide a Beacon frame period into 24 time slots, and the time slot number is 0-23. The access point may send the division rule of the above time slot to all stations by using a broadcast message.

The access point groups the sites according to the priority of the data transmission by the site, that is, the sites with higher priority are grouped into one group, and the sites with lower priority are grouped into one group. The access point allocates the time slot with the slot number 0 to 14 to the station group with the higher priority, and allocates the time slot corresponding to the other slot number to the station group with the lower priority.

STA1 is a high priority site, and STA2 and STA3 are low priority sites. As shown in Figure 7, STA1, STA2, and STA3 need to perform data transmission at the same time at T1. After listening to the idle time of the channel to reach the DIFS duration (assuming the duration of the DIFS is 2 slots), they are randomly selected from the contention window. A backoff delay is 2 slots, 5 slots, and 7 slots, and the timer is turned on to count down. Since the backoff delay of STA1 is short, the countdown is cleared first, and the slot number corresponding to the current slot is 4, and STA1 is allowed to occupy the channel for data transmission in the current slot, so STA1 corresponds to slot number 4. The occupied channel on the slot starts data transmission. At this time, STA2 And STA3 monitors that the channel is occupied, so STA2 and STA3 pause the countdown, and at this time, there are 3 slots and 5 slots respectively. After the STA1 data transmission ends, STA2 and STA3 monitor the channel idle duration to reach the DIFS duration, continue counting down, clear the timer after 3 slots, the slot number of the current slot is 14, and the slot number 14 corresponds. The time slot is a time slot available to the high priority station, and STA2 is a low priority station. Therefore, STA2 cannot start data transmission in the current time slot, and needs to wait. When the time slot number 15 arrives, STA2 listens to the channel. Still in the idle state, STA2 occupies the channel on the time slot corresponding to slot number 15 to start data transmission. At this time, STA3 monitors that the channel is occupied, so STA3 pauses the countdown, and one slot remains at this time. After STA2 data transmission ends, STA3 monitors the channel idle duration to reach the DIFS duration, and continues to count down. After 1 slot, the timer is cleared. The current slot number is 21, and STA3 can start data in the current slot. Transmission, so STA3 begins to occupy the channel for data transmission.

Based on the same technical concept, the embodiment of the present invention further provides a site for implementing a point-to-multipoint channel allocation method according to an embodiment of the present invention to occupy a channel for data transmission.

FIG. 8 is a schematic structural diagram of a first site according to an embodiment of the present invention. As shown in the figure, the first site includes: a listening module 801, a contention module 802, a determining module 803, and a transmitting module 804. Further, The site may also include a receiving module 805.

The listening module 801 is configured to monitor whether the channel is in an idle state.

The competing module 802 is configured to compete with other stations for the channel after the listening module 801 monitors that the channel is in an idle state. The other sites are one or more sites other than the first site that access the same access point.

The determining module 803 is configured to determine, when the contention module 802 successfully contends to the channel, whether the current time slot is a time slot corresponding to the time slot number that allows the first station to start data transmission.

The transmission module 804 is configured to: if the determining module 803 determines that the current time slot is a time slot corresponding to the time slot number that allows the first station to start data transmission, and then uses the current time slot to occupy the channel to perform data transmission to the access point; otherwise, wait When the time slot corresponding to the slot number that allows the first station to start data transmission arrives, the occupied channel performs data transmission to the access point.

The above channel is a channel commonly used by multiple sites accessing the access point.

Optionally, the slot number that allows the first station to start data transmission is sent by the access point to the first station.

Optionally, the receiving module 805 is specifically configured to receive a broadcast message sent by the access point, where the broadcast message includes a correspondence between the identifier of the site group and a slot number that allows the station in the site group to start data transmission. The first station sets the identifier of the station group in which it is located in the corresponding slot number in the above correspondence as the slot number that allows the first station to start data transmission.

Optionally, the site group is divided according to the priority of the data transmission by the site, and the number of the slot number in the site group with the higher priority is allowed to start data transmission is greater than or equal to the site in the site group with the lower priority. The number of slot numbers that are allowed to begin data transmission.

Alternatively, the site group may also be divided according to the value of the site's association identifier AID.

Optionally, the contention module 802 is specifically configured to: determine a backoff delay duration, where the backoff delay duration is a backoff delay duration selected from a preset plurality of delay durations; and when the channel idle state reaches a backoff The delay time, that is, the first station successfully competes for the channel.

Optionally, when the listening channel is in an idle state, the foregoing monitoring module 801 is specifically configured to: when the listening channel is idle for a preset duration, determine that the channel is in an idle state.

FIG. 9 is a second schematic structural diagram of a first site according to an embodiment of the present invention. As shown in the figure, the first site includes: a processor 901, a memory 902, a transceiver 903, and a bus interface.

The transceiver 903 is configured to receive and transmit data under the control of the processor 901.

The memory 902 is used to store a preset program and data used by the processor 901 when performing an operation.

The processor 901 is configured to read a program saved in the memory 902, and execute the following process according to the program:

After the channel is in the idle state, the channel is contending with other stations; when successfully competing for the channel, it is determined whether the current time slot is a time slot corresponding to the time slot number that allows the first station to start data transmission; if the current time slot is determined In order to allow the first station to start the time slot corresponding to the slot number of the data transmission, the channel occupied by the current slot is transmitted to the access point through the transceiver 903. Otherwise, waiting for the first station to start data transmission. When the time slot corresponding to the slot number arrives, the occupied channel Data transmission is performed to the access point by the transceiver 903. The other sites are one or more sites other than the first site that are connected to the same access point.

The above channel is a channel used by a plurality of sites accessing the access point to compete for use.

Optionally, the processor 901 is configured to receive, by using the transceiver 903, a broadcast message sent by the access point, where the broadcast message includes the identifier of the site group and the time slot number of the site in the site group to start data transmission. Relationship; the slot number corresponding to the identifier of the site group in which the identity is located in the above correspondence relationship is used as the slot number that allows the first station to start data transmission.

Optionally, the processor 901 is specifically configured to: determine a backoff delay duration, where the backoff delay duration is a backoff delay duration selected from a preset plurality of delay durations; when the channel is idle The duration reaches the backoff delay duration, that is, the first station successfully competes for the channel.

Optionally, the processor 901 is configured to: when the listening channel is in an idle state, is configured to: when the duration of the channel being idle is reached, the channel is in an idle state.

Based on the same technical concept, an embodiment of the present invention provides an access point for implementing the foregoing method embodiments.

FIG. 10 is a schematic structural diagram of an access point according to an embodiment of the present invention. As shown in the figure, the access point includes: a determining module 1001 and a sending module 1002.

The determining module 1001 is configured to determine a slot number of the first station that allows access to the access point to start data transmission.

The sending module 1002 is configured to send the determined time slot number to the first station, so that the first station contends with other stations after listening to the channel in an idle state, and is allowed to start after successfully competing to the channel. When the time slot corresponding to the slot number for data transmission arrives, the channel is occupied. The access point begins data transmission. The other sites are one or more sites other than the first site that access the access point.

Optionally, the determining module 1001 is specifically configured to: group the stations that access the access point; and assign each station group a slot number that allows the stations in the group to start data transmission.

The sending module 1002 is specifically configured to: send a broadcast message, where the broadcast message includes a correspondence between an identifier of the site group and a slot number that allows the station in the site group to start data transmission.

Optionally, the foregoing group of sites is divided according to the priority of the data transmission by the site, and the number of the slot numbers in the site group with the higher priority is allowed to start data transmission is greater than or equal to the number of the site group with the lower priority. The number of slot numbers that the station is allowed to begin data transmission.

FIG. 11 is a second schematic structural diagram of an access point according to an embodiment of the present invention. As shown in the figure, the station includes: a processor 1101, a memory 1102, a transceiver 1103, and a bus interface.

The transceiver 1103 is configured to receive and transmit data under the control of the processor 1101.

The memory 1102 is used to store a preset program and data used by the processor 1101 when performing an operation.

The processor 1101 is configured to read a program saved in the memory 1102, and execute the following process according to the program:

Determining, for the accessed first station, a slot number that allows data transmission to begin, and then transmitting the determined slot number to the first station through the transceiver 1103, so that the first station after listening to the channel is in an idle state The other stations compete for the channel, and after successfully competing for the channel, when the time slot corresponding to the slot number that allows the data transmission to start to arrive, the occupied channel starts transmitting data to the access point. The above channel is a channel commonly used by multiple sites accessing the access point. The other sites are one or more sites other than the first site that access the access point.

Optionally, when determining, by the first station that is the access, the slot number that is allowed to start data transmission, the processor 1101 is specifically configured to: group the stations that access the access point; and assign an allowable pair to each station group. The time slot number of the data transmission should be started by the station in the site group; the broadcast message is sent by the transceiver 1103, and the broadcast message includes the identifier of the site group and the number of sites in the allowed site group. According to the correspondence of the transmitted slot numbers.

Optionally, the foregoing group of sites may be prioritized according to the priority of the data transmission by the site, and the number of the slot numbers in the site group with the higher priority is allowed to start data transmission is greater than or equal to the group group with the lower priority. The number of time slots in which the site is allowed to start data transmission.

Based on the same technical concept, the embodiment of the present invention further provides a point-to-multipoint system for implementing a situation in which data transmission conflict occurs when multiple stations compete for a channel. The system includes an access point as described above, and N stations as described above, where N is an integer greater than one.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

While the preferred embodiment of the invention has been described, it will be understood that Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and the modifications and

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims

A point-to-multipoint channel allocation method is applied to a scenario where multiple sites access an access point, and is characterized by:

After the first station monitors that the channel is in an idle state, it competes with other stations for the channel; the other station is one or more sites other than the first site that access the access point;

When the first station successfully contends to the channel, determining whether the current time slot is a time slot corresponding to a time slot number that allows the first station to start data transmission;

If the first station determines that the current time slot is a time slot corresponding to a time slot number that allows the first station to start data transmission, the first station occupies the channel to the access in the current time slot. Point data transmission; otherwise, when the time slot corresponding to the time slot number that allows the first station to start data transmission arrives, the channel is occupied to perform data transmission to the access point.
The method of claim 1, wherein the slot number that allows the first station to initiate data transmission is sent by the access point to the first station.
The method of claim 2, further comprising:

Receiving, by the first station, a broadcast message sent by the access point, where the broadcast message includes a correspondence between an identifier of a site group and a slot number that allows a station in the site group to start data transmission;

The first station sets the identifier of the station group in which the identity is located in the corresponding slot number in the corresponding relationship as a slot number that allows the first station to start data transmission.
The method according to claim 3, wherein said group of stations is divided according to a priority of data transmission by a station, and a number of time slot numbers of stations in a group of higher priority groups are allowed to start data transmission. The number of slot numbers that are allowed to start data transmission for stations greater than or equal to the lower priority group.
The method of claim 3 wherein said set of sites is partitioned according to a value of a correlation identifier AID of the site.
The method of claim 1 wherein said first site competes with other sites for said channel, comprising:

The first station determines a backoff delay duration, and the backoff delay duration is a backoff delay duration selected from a preset plurality of delay durations;

When the duration of the channel idle state reaches the backoff delay duration, the first station successfully contends to the channel.
The method of claim 1, wherein the first station monitors that the channel is in an idle state, including:

The first station monitors that the channel is idle for a preset duration.
A point-to-multipoint channel allocation method is applied to a scenario where multiple sites access an access point, and is characterized by:

The access point determines a slot number that allows access to the first station of the access point to begin data transmission;

Sending, by the access point, the determined time slot number to the first station, so that the first station competes with other stations for the channel after listening to the channel being in an idle state, after successfully competing for the channel, When a time slot corresponding to a slot number that is allowed to start data transmission arrives, occupying the channel starts data transmission to the access point; the other station is connected to the access point except One or more other sites outside the first site.
The method according to claim 8, wherein the access point determines a slot number that allows access to the first station of the access point to start data transmission, including:

The access point will group the stations accessing the access point;

The access point assigns, to each site group, a slot number that allows data transmission to start at a site in the site group;

Sending, by the access point, the determined time slot number to the first station, including:

The access point sends a broadcast message, where the broadcast message includes a correspondence between an identifier of the site group and a slot number that allows the station in the site group to start data transmission.
The method according to claim 9, wherein said group of stations is divided according to a priority of data transmission by a station, and a station of a group of higher priority is allowed to start a slot number of data transmission. Sites in the site group with a number greater than or equal to the lower priority are allowed to start The number of slot numbers for line data transmission.
A site is applied to a scenario where multiple sites access to an access point, and the site serves as a first site, and is characterized by:

a monitoring module, configured to monitor whether the channel is in an idle state;

a competition module, configured to: when the listening module monitors that the channel is in an idle state, compete with other stations for the channel; the other station is another one of the access points except the first station Or multiple sites;

a determining module, configured to determine, when successfully competing for the channel, whether the current time slot is a time slot corresponding to a time slot number that allows the first station to start data transmission;

a transmission module, configured to: if the determining module determines that the current time slot is a time slot corresponding to a time slot number that allows the first station to start data transmission, occupying the channel to the access point in the current time slot Data transmission is performed; otherwise, when the time slot corresponding to the slot number that allows the first station to start data transmission arrives, the channel is occupied to perform data transmission to the access point.
The station according to claim 11, wherein said slot number that allows said first station to start data transmission is sent by said access point to said first station.
The site of claim 12, further comprising: a receiving module, configured to:

Receiving, by the access point, a broadcast message, where the broadcast message includes a correspondence between an identifier of the site group and a slot number that allows the station in the site group to start data transmission;

The identifier of the station group in which the identity is located is in the corresponding slot number in the corresponding relationship, as a slot number that allows the first station to start data transmission.
The station according to claim 13, wherein said group of stations is divided according to a priority of data transmission by a station, and a number of time slot numbers of stations in a group of higher priority are allowed to start data transmission. The number of slot numbers that are allowed to start data transmission for stations greater than or equal to the lower priority group.
The station of claim 13 wherein said set of sites is partitioned according to a value of a link identifier AID of the site.
The site of claim 11, wherein the contention module is specifically configured to:

Determining a backoff delay duration, wherein the backoff delay duration is a backoff delay duration selected from a preset plurality of delay durations;

When the duration of the channel idle state reaches the backoff delay duration, the first station successfully contends to the channel.
The station according to claim 11, wherein the listening module is specifically configured to: when the listening channel is in an idle state:

When it is monitored that the channel is idle for a preset duration, it is determined that the channel is in an idle state.
An access point is applied to a scenario where multiple sites access to an access point, and is characterized by:

a determining module, configured to determine a slot number of a first station that allows access to the access point to start data transmission;

a sending module, configured to send the determined time slot number to the first station, so that the first station contends with other stations after listening to the channel being in an idle state, and after successfully competing for the channel, When the time slot corresponding to the slot number that is allowed to start data transmission arrives, the channel is occupied to start data transmission to the access point; the other station is the first to access the access point except the first One or more other sites outside the site.
The access point according to claim 18, wherein the determining module is specifically configured to:

Grouping the sites accessing the access point; assigning each site group a slot number that allows data to be transmitted to the site in the site group;

The sending module is specifically configured to:

A broadcast message is sent, where the broadcast message includes a correspondence between an identifier of the site group and a slot number that allows the station in the site group to start data transmission.
The access point according to claim 19, wherein the group of stations is a slot number that is allowed to start data transmission according to a priority of data transmission by the station, and a station in the group of higher priority is allowed to start data transmission. The number of sites in the site group whose number is greater than or equal to the lower priority is allowed to start The number of slot numbers for line data transmission.
A point-to-multipoint system, comprising: an access point according to any one of claims 18 to 20 and a site according to any one of claims 11 to 17, wherein , N is an integer greater than one.