CN109644502B

CN109644502B - Point-to-multipoint channel allocation method, device and system

Info

Publication number: CN109644502B
Application number: CN201680088563.8A
Authority: CN
Inventors: 何孝月; 孙方林; 吕捷; 陈维熙
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2016-12-13
Filing date: 2016-12-13
Publication date: 2020-09-25
Anticipated expiration: 2036-12-13
Also published as: WO2018107370A1; CN109644502A

Abstract

A method, a device and a system for allocating point-to-multipoint channels are provided. In the method, an access point configures a time slot number for a station to allow the station to start occupying a channel for data transmission, and sends the time slot number to the station; and after monitoring that the channel is in an idle state, the station competes with other stations for the channel, determines whether the current time slot is the time slot corresponding to the time slot number allowing the station to start data transmission when successfully competing for the channel, and if the current time slot is the time slot allowing the station to start data transmission, the station occupies the channel to transmit data to the access point in the current time slot, otherwise, the station occupies the channel to transmit data to the access point when waiting for the time slot corresponding to the time slot number allowing the station to start data transmission. By the method, the situation that the plurality of stations conflict when occupying the same channel to transmit data is reduced while the transmission efficiency is not influenced.

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 method, an apparatus, and a system for allocating a point-to-multipoint channel.

Background

A WLAN (Wireless Local Area network) based on IEEE 802.11 standard has been widely used in homes, office environments, airports, bus stations, and other places to provide network access services for users. As the demand for information increases, higher demands are also placed on network data transmission rates. The physical layer rate of wlan is gradually increased from 2Mbps to 11Mbps, and then to 54Mbps, and nowadays, wlan with over 100Mbps is also used.

Current work at the MAC layer based on the 802.11 standard focuses mainly on how to improve the throughput and delay performance of the network. The standard of the wireless network channel access control method based on the 802.11 standard mainly includes PCF (Point Coordination Function) and DCF (Distributed Coordination Function). Because DCF is simpler to implement, DCF is currently supported by most manufacturers.

The DCF allows the terminal to perform channel contention after monitoring the idle channel based on a CSMA/CA (carrier sense multiple access with collision avoidance) mechanism and a binary exponential backoff mechanism, so as to implement that different stations accessing the same access point compete for the same channel to perform data transmission to the access point through a carrier sense multiple access with collision avoidance. As shown in fig. 1, the channel is initially used by station a (station a), and after station a finishes transmitting, station B, C, D senses that the channel is idle for a time period exceeding DIFS, and therefore, it is determined that the channel is idle, and a back-off delay duration (shown in fig. 1 as 12 slots, 6 slots, and 8 slots, respectively) is generated, and then the countdown is started. Because the backward time generated by the station C is the minimum (6 time slots), the station C first counts down and clears the time, and preferentially acquires the channel use right to perform data transmission. After the station C starts data transmission, the station B and the station D monitor that the channel is occupied, so that countdown is suspended, and the remaining time lengths are 6 time slots and 2 time slots respectively. After the data transmission of the station C is finished, the station B and the station D sense that a time channel exceeding DIFS (Distributed Inter-frame spacing) is idle, and continue to count down. After 2 slots, station D starts data transmission, while station B listens that the channel is occupied, pausing the countdown again.

The backoff delay time duration of each station is randomly selected from the contention windows (0 to CW), and there is a possibility that data transmission collisions are caused by the same random backoff time of a plurality of stations. If the competition window is smaller, the probability of conflict is higher; if the contention 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 consider avoiding conflict and ensuring efficiency becomes a problem to be solved urgently at present.

Disclosure of Invention

The embodiment of the invention provides a point-to-multipoint channel allocation method, a device and a system, which are used for reducing the conflict when a plurality of stations occupy the same channel to transmit data without influencing the transmission efficiency.

In a first aspect, a point-to-multipoint channel allocation method provided in an embodiment of the present invention may be applied to a scenario where multiple stations access to one access point, where the method includes:

after monitoring that the channel is in an idle state, the first station competes for the channel with other stations, wherein the other stations are one or more other stations except the first station, which are accessed to the access point; and when the channel is successfully contended, the first station judges the current time slot, if the current time slot is determined to be the time slot corresponding to the time slot number allowing the first station to start data transmission, the first station occupies the channel in the current time slot to transmit data to the access point, otherwise, the first station occupies the channel to transmit data to the access point when waiting for the time slot corresponding to the time slot number allowing the first station to start data transmission. The channel is a channel which is used by a plurality of stations accessing the access point in a joint competition mode.

In the method, the first station starts data transmission only on the time slot corresponding to the time slot number allowed to start data transmission, so that the occurrence of data transmission failure caused by the fact that a plurality of stations occupy the channel to transmit data at the same time is reduced.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the timeslot number that allows the first station to start data transmission is sent by the access point to the first station. The access point sends the time slot number allowing the first station to start data transmission to the first station, so that the access point can regulate and control the data transmission of the access station according to the number of the stations accessing the access point and the service performed by the stations.

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, after accessing the access point, the first station is assigned to a station group, and stations in the same station group are configured with the same timeslot number that allows starting data transmission. The first station receives a broadcast message sent by the access point, wherein the broadcast message comprises a corresponding relation between the identifier of the station group and a time slot number allowing the station in the station group to start data transmission. The first station may determine, according to the identifier of the station group where the first station is located and the correspondence, a time slot number that allows the first station to start data transmission.

According to the result of statistics of the frequency of data transmission of the stations, it is found that the same time slot numbers allowing the start of data transmission are configured for a group of stations, the probability of data transmission conflict is not increased remarkably, and in consideration of the limited number of time slots, when the method is applied to public places such as office environments and airports and the like and the number of accessed stations is large, the accessed stations can be divided into groups, and the same time slot numbers allowing the start of data transmission are configured for a group of stations, so that the utilization rate of the time slots is improved, and the data transmission efficiency of the system is improved.

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 station groups may be divided according to priorities of the stations for data transmission, and the number of time slot numbers, in which the stations in the station group with a high priority are allowed to start data transmission, is greater than or equal to the number of time slot numbers, in which the stations in the station group with a low priority are allowed to start data transmission.

In some application scenarios, the priorities of data transmission performed by different stations may be different, and the stations with high priorities may be grouped into one group; or, the priorities of the service types of data transmission may be different, and the station groups may be dynamically updated according to the priorities of the service types of data transmission by the station. In order to ensure that stations in a station group with a higher priority can perform data transmission in time and reduce the occurrence of data transmission conflicts of the stations, a station group with a higher priority may be assigned with a larger number of time slot numbers, and a station group with a lower priority may be assigned with a smaller number of time slot numbers, so as to reduce the time delay and the occurrence of data transmission conflicts when the stations with a higher priority perform data transmission.

With reference to the first aspect and the first possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the station groups may be divided according to AIDs of stations. When the accessed stations have no priority level differentiation or the service types of the transmission data have no priority level differentiation, the stations can be grouped according to the AIDs of the stations, and the method is simple to operate and easy to implement.

With reference to the first aspect, in a fifth possible implementation manner of the first aspect, after the first station needs to perform data transmission and the station monitors that the channel is in an idle state, the first station may select one backoff delay time from a plurality of preset delay times and start to count down, and after the countdown is cleared, the first station determines whether the current time slot is a time slot allowing the first station to start data transmission. And if the time slot is the time slot allowing the first station to start data transmission, the first station occupies the channel to start data transmission, otherwise, the first station occupies the channel to start data transmission when waiting for the time slot corresponding to the time slot number allowing the first station to start data transmission. And if the channel is occupied in the waiting period, the first station waits for the channel to be idle again and occupies the channel to start data transmission when the time slot corresponding to the time slot number allowing the first station to start data transmission arrives.

By selecting one backoff delay time length for each station, the possibility of collision when a plurality of stations transmit data can be further reduced. For example, a plurality of stations that start data transmission using a time slot corresponding to the same time slot number need to perform data transmission at the same time, and if the channel is monitored to be in an idle state at the same time, a collision may occur; and each station selects one back-off delay time length, and when the back-off delay time lengths are different, the occurrence of collision is avoided.

Specifically, the first station may randomly select a backoff delay time duration from a plurality of preset delay time durations; the selection may also be performed according to the priority of the first station for data transmission, for example, a station with a higher priority selects a shorter back-off delay duration, and a station with a lower priority selects a longer back-off 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 in an idle state, if a duration that the first station monitors that the channel is idle reaches a preset duration, the channel is considered to be available. And the first station carries out data transmission after the time length for monitoring the idle state of the channel reaches the preset time length, so that a certain interval exists between two data transmissions, and the access points can be distinguished.

In a second aspect, a point-to-multipoint channel allocation method provided in an embodiment of the present invention is applied in a scenario where multiple stations access to an access point, and includes:

the access point determines a time slot number allowing the access point to start data transmission for an accessed first station, and then sends the determined time slot number to the first station, so that the first station competes with other stations for a channel after needing to perform data transmission and monitoring that the channel is in an idle state, and occupies the channel to start data transmission to the access point when a time slot corresponding to the time slot number allowed to start data transmission arrives after successfully competing for the channel. The other stations are one or more stations except the first station which are accessed to the access point, and the channel is a channel which is used by a plurality of stations accessed to the access point in a competition mode.

In the method, the access point sends the time slot number allowing the first station to start data transmission to the first station, so that the first station starts data transmission at the time slot corresponding to the time slot number allowing the first station to start data transmission, and the occurrence of data transmission failure caused by the fact that a plurality of stations occupy channels to transmit data at the same time is reduced.

With reference to the second aspect, in a first possible implementation manner of the second aspect, when determining a timeslot number that allows the first station to start data transmission, the access point may first group the first stations, and then configure, for each station group, a timeslot number that allows stations in the station group to start data transmission. The access point sends the corresponding relation between the identification of the station group and the time slot number allowing the stations in the station group to start data transmission to the first station through a broadcast message, so that the first station determines the time slot number allowed to start data transmission.

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 stations, the stations may be divided according to priorities of the stations for performing data transmission, and configure a larger number of timeslot numbers for allowing the stations to start data transmission in a station group with a high priority, and configure a smaller number of timeslot numbers for allowing the stations to start data transmission in a station group with a low priority.

With reference to the second aspect and the first possible implementation manner of the second aspect, in a third possible implementation manner of the second aspect, the station groups may be divided according to AIDs of stations. When the accessed stations have no priority level differentiation or the service types of the transmission data have no priority level differentiation, the stations can be grouped according to the AIDs of the stations, and the method is simple to operate and easy to implement.

In a third aspect, a station provided in an embodiment of the present invention is applied to a scenario in which multiple stations access to an access point, where the station is a first station, and the first station includes:

and the monitoring module is used for monitoring whether the channel is in an idle state.

The competition module is used for competing the channel with other stations after the monitoring module monitors that the channel is in an idle state; the other stations are one or more stations other than the first station that access the access point.

And the determining module is used for determining whether the current time slot is the time slot corresponding to the time slot number allowing the first station to start data transmission when the channel is successfully contended.

A transmission module, configured to, if the determination module determines that the current time slot is a time slot corresponding to a time slot number allowing the first station to start data transmission, occupy the channel in the current time slot to perform data transmission to the access point; otherwise, when waiting for the time slot corresponding to the time slot number allowing the first station to start data transmission, occupying the channel to transmit data to the access point.

The channel is a channel which is used by a plurality of stations accessed to the access point in a joint competition mode.

With reference to the third aspect, in a first possible implementation manner of the third aspect, the time slot number allowing the first station to start data transmission is sent by the access point to the first station.

With reference to the third aspect, in a second possible implementation manner of the third aspect, the first station further includes a receiving module, specifically configured to: and receiving a broadcast message sent by the access point, wherein the broadcast message comprises the corresponding relation between the identifier of the site group and the time slot number allowing the sites in the site group to start data transmission. The first station may use the time slot number corresponding to the identifier of the station group where the first station is located in the corresponding relationship as the time slot number allowing 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 station groups are divided according to priorities of the stations for data transmission, and the number of time slot numbers, at which the stations in the station group with a high priority are allowed to start data transmission, is greater than or equal to the number of time slot numbers, at which the stations in the station group with a low priority are 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 station groups are divided according to a numerical value of an association identifier AID of a station.

With reference to the third aspect, in a fifth possible implementation manner of the third aspect, the contention module is specifically configured to: determining a backoff delay time length which is selected from a plurality of preset delay time lengths; and when the time length of the channel idle state reaches the backoff delay time length, the first station successfully competes to the channel.

With reference to the third aspect, in a sixth possible implementation manner of the third aspect, when the monitoring channel is in an idle state, the monitoring module is specifically configured to: and determining that the channel is in an idle state if the time length of the channel in the idle state reaches the preset time length.

In a fourth aspect, an access point provided in an embodiment of the present invention is applied to a scenario in which multiple stations access to one access point, and includes:

and the determining module is used for determining the time slot number of the first station which is allowed to access the access point and starts data transmission.

A sending module, configured to send the determined time slot number to the first station, so that the first station competes for a channel with other stations after monitoring that the channel is in an idle state, and occupies the channel to start data transmission to the access point when a time slot corresponding to a time slot number allowed to start data transmission arrives after successfully competing for the channel; the other stations are one or more other stations except the first station which are accessed to the access point.

With reference to the fourth aspect, in a first possible implementation manner of the fourth aspect, the determining module is specifically configured to: grouping stations accessing the access point; each station group is assigned a time slot number that allows the stations in the corresponding station group to begin data transmission.

The sending module is specifically configured to: and sending a broadcast message, wherein the broadcast message comprises the corresponding relation between the identifier of the site group and the time slot number allowing the sites 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 a second possible implementation manner of the fourth aspect, the station groups are divided according to priorities of the stations for data transmission, and the number of time slot numbers, in which the stations in the station group with a high priority are allowed to start data transmission, is greater than or equal to the number of time slot numbers, in which the stations in the station group with a low priority are allowed to start data transmission.

In a fifth aspect, an 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 an integer greater than 1.

Drawings

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

FIG. 1 is a diagram illustrating a prior art CSMA/CA mechanism-compliant station for data transmission;

FIG. 2 is a diagram illustrating a data transmission collision in the prior art;

fig. 3 is a schematic diagram of a WLAN network architecture adapted to the point-to-multipoint channel allocation method provided by the embodiment of the present invention;

fig. 4 is a schematic time slot diagram provided in an embodiment of the present invention;

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

FIG. 6 is a schematic diagram of an embodiment of the present invention;

FIG. 7 is a schematic diagram of another embodiment of the present invention;

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

fig. 9 is a schematic structural diagram of another station provided in the embodiment of the present invention;

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

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 apparent, the present invention will be described in further detail with reference to the accompanying drawings.

When each station transmits data to the access point according to the CSMA/CA mechanism in the 802.11 wireless lan protocol, a possibility of data transmission collision may still occur, as shown in fig. 2. When the data transmission of the station A is finished, the idle time of other stations for monitoring the channel reaches the DIFS time length, the station B, the station C, the station D and the station E respectively randomly select a backoff delay time length from a competition window, wherein the backoff delay time length is respectively 12 time slots, 2 time slots, 8 time slots and 8 time slots, and the countdown is started. Typically, the initial contention window is [0, 15] (unit: slot). Because the length of the backoff delay of the station C is shortest, the station C firstly counts down and clears, so that the station C occupies a channel to start data transmission. After the station C starts data transmission, the stations B, D and E monitor that the channels are occupied, and suspend countdown, at which time the backoff delay time durations of the stations B, D and E still remain 10 slots, 6 slots, and 6 slots. After the data transmission of the station C is finished, the stations B, D and E monitor that the idle time of the channel reaches the DIFS duration, countdown is continued, and as the remaining backoff delay durations of the stations D and E are the same and the countdown is cleared, the stations D and E transmit data at the same time, conflict occurs, and the access point cannot normally receive the data. If the station D and the station E do not receive the successful reception response message sent by the access point or receive the data transmission acknowledgement message (acknowledgement) sent by the access point within the preset time, but the message indicates that the data transmission fails, the station D and the station E expand the contention window by one time to [0, 31], and reselect a backoff delay duration from the new contention window, which is 20 slots and 28 slots as shown in the figure, and restart the countdown. Since the station B only has 4 time slots, the station B firstly counts down and clears the time slot, and occupies the channel to carry out data transmission. And when the station D and the station E detect that the channel is occupied, the countdown is suspended, and at the moment, 16 time slots and 24 time slots are respectively remained. After the data transmission of the station B is finished, after the station D and the station E monitor that the channel idle time reaches the DIFS time, counting down is continued, the remaining time slots of the station D are few, the counting down is cleared first, and therefore the station D occupies the channel to perform data transmission. And after the transmission of the site D is finished, the site E occupies the channel to carry out data transmission.

In the prior art, after a station D and a station E successfully transmit data, a contention window may be restored to a smaller contention window before; if station D or station E continuously conflicts, the contention window may be expanded again to 2m times the original window, where m is the number of times that conflicts continuously occur. Typically, a maximum contention window size is set, and when the contention window is enlarged to the maximum, the window is not enlarged.

It can be seen that the selection of the contention window affects the performance of the system transmission. If the contention window is too small, backoff delay time lengths randomly selected by a plurality of stations may be the same, and data transmission collision may occur; if the contention window is too large, unnecessary delay may be generated, which affects transmission efficiency, and especially under the condition of high network load, the QoS (Quality of Service) requirements of some stations having higher requirements on transmission rate or delay cannot be satisfied.

In order to solve the above problem, an embodiment of the present invention provides a point-to-multipoint channel allocation method, so as to reduce the occurrence of collisions when multiple stations occupy the same channel to transmit data, while not affecting transmission efficiency. The method may be applied in a WLAN network architecture as shown in fig. 3, which includes an Access Point (AP) and a Station (STA). The access point may be a device with a 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); the station can be a mobile phone, a tablet computer, a wireless internet notebook computer or other devices capable of accessing a wireless network through a WLAN.

The access point periodically broadcasts and sends a Beacon frame to the stations within the range of the access point to inform the stations of knowing the existence of the access point, so that the stations establish connection with the access point according to the information in the Beacon frame. The access point may divide the time between two Beacon frames into multiple time slots of equal duration and number each time slot as shown in fig. 4. The duration of each time slot, how many time slots in total, can be controlled by the access point. The access point may inform the division principle of the time slots of each station through Beacon frames or other broadcast messages.

In addition, the access point may notify the station through a reserved bit in the Operating Mode Field subfield in the Operating Mode Notification Field in the Beacon frame, and whether the point-to-multipoint channel allocation method provided by the embodiment of the present invention needs to be applied when data transmission is performed.

The Operating Mode Field subfield includes a total of 8 bytes as shown in table 1.

TABLE 1

The access point can inform the station whether to apply the point-to-multipoint channel allocation method provided by the embodiment of the invention through the reserved bits B2 and B3. For example, if the values of B2 and B3 are 01, this indicates that the channel allocation method provided by the embodiment of the present invention is applied.

Referring to fig. 5, a flowchart of a point-to-multipoint channel allocation method provided in an embodiment of the present invention is shown, where the method specifically includes the following steps:

step 501, the access point determines a time slot number for a first station allowed to access the access point to start occupying a channel for data transmission.

The channel is a channel used by a plurality of stations accessing the access point in a contention mode, and may be used by a carrier sense multiple access with collision avoidance, for example. Therefore, in order to reduce the occurrence of transmission failure caused by simultaneous occupation of channels by multiple stations for data transmission, the access point configures, for each accessed station, a time slot number allowing the station to start occupying the channel for data transmission, so that the station starts data transmission at a time slot corresponding to the time slot number allowed to start occupying the channel for data transmission.

Note that the "first station" is used herein to distinguish from other stations accessing the access point, and is not particularly limited to a certain station.

In particular, the access point may be configured with a time slot number that allows the start of data transmission when the first station accesses the access point.

In some embodiments, the access point may group the stations accessing the access point, and configure a timeslot number allowing the start of data transmission for the group of stations, that is, a certain station may only start data transmission on a timeslot corresponding to the timeslot number corresponding to the group of stations where the station is located, but may not occupy timeslots corresponding to timeslot numbers corresponding to other groups.

The data transmission frequency of the sites is analyzed in advance, the result shows that a group of sites is configured with the same time slot number allowing the data transmission to be started, the probability of data transmission conflict is not obviously increased, the limited time slot number is considered, the accessed sites can be divided into groups when the method is applied to public places such as office environments and airports and the like and the number of the accessed sites is large, the same time slot number allowing the data transmission to be started is configured for the group of sites, the utilization rate of time slots is improved, and the data transmission efficiency of the system is improved.

Optionally, when the stations are grouped, the stations may be grouped in the following manner:

1) grouping according to AID (Association identifier) of station

An access point can access a large number of stations, so the access point can assign an AID to each station for station differentiation, and each AID corresponds to the MAC address of the station corresponding to the AID in an AID Table (AID tag) of the access point, so that the access point can manage the stations with a large number of stations conveniently. The AID value range is 0-2007, wherein AID 0 is a reserved field and is not allocated to a station to represent multicast and broadcast, and therefore AIDs which can be allocated to the station are 1-2007.

The access point may group stations by parity of AIDs, i.e., groups stations with odd AIDs and groups stations with even AIDs.

When the number of stations accessed is large, the access point can also divide the stations into a plurality of station groups according to AIDs. Taking the example of dividing the accessed stations into 4 groups, stations with (AID mod4) ═ 0 can be divided into one group, stations with (AID mod4) ═ 1 can be divided into one group, stations with (AID mod4) ═ 2 can be divided into one group, and stations with (AID mod4) ═ 3 can be divided into one group.

The access point may also group stations whose AIDs are within a certain range, e.g., group stations whose AIDs belong to [1, 10], and group other stations. It should be understood that the above numerical values are exemplary only, and that the specific ranges may have other numerical ranges or non-continuous numerical values.

Of course, the access point groups stations in other ways according to AIDs, which is not illustrated here.

When there is no priority level differentiation among a plurality of accessed sites, or there is no priority level of the service type of data transmission, the sites are grouped according to AID, the operation is simple, and the implementation is easy.

2) Grouping according to priority of data transmission by station

In some scenarios, there may be different requirements for the data transmission rate by different stations, some stations have higher requirements for the transmission rate, and some stations have no excessively high requirements for the transmission rate, and in this case, the access point may group the stations requiring higher transmission rate into one group, i.e., a high priority station group, and group the stations having no additional requirements for the transmission rate into one group, i.e., a low priority station group.

In some scenarios, different stations may have different priorities for data transmission. For example, the internet of things equipment needs to automatically report measurement data and can be set to be high priority; whereas a cell phone or tablet computer typically used for entertainment activities may be set to a low priority. The access point may group stations with high data transmission priority into one group and group stations with low data transmission priority into one group.

In other scenarios, due to the different priorities of different data transmission service types, the stations that need to perform data transmission of the high priority service type may be grouped together. For example, video traffic may be set to a high priority, and other traffic may be set to a low priority, based on which, stations that need to perform video data transmission may be divided into a high priority station group, and stations that perform other types of data transmission may be divided into a low priority station group. Since the same station may need to transmit data of a low priority traffic type after transmitting data of a high priority traffic type, the grouping information of the station needs to be dynamically updated.

Of course, the grouping information may be updated in other grouping manners, for example, when a new station accesses, the grouping may be performed again or the newly accessed station may be grouped into an existing station group. In addition, in addition to the 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 a timeslot number for allowing data transmission to start for different station groups, the configuration may be performed in the following manner:

1) configuring according to AID of station

When the stations are grouped, the stations with odd AIDs are grouped into one group, and the stations with even AIDs are grouped into one group, the access point may allocate the slot with the odd slot number to the station group with odd AID, and allocate the slot with the even slot number to the station group with even AID.

If the stations are grouped, the stations are divided into M groups according to the remainder of dividing the AID by M, and then the access point may divide the time slots into M groups according to the remainder of dividing the time slot number by M, and allocate the time slots to corresponding station groups. Still taking the example of dividing the stations into 4 groups, a Slot Number of (Slot Number mod 2) ═ 0 may be assigned to a station group of (AID mod4) ═ 0, a Slot Number of (Slot Number rmod 2) ═ 1 may be assigned to a station group of (AID mod4) ═ 1, a Slot Number of (Slot Number mod 2) ═ 2 may be assigned to a station group of (AID mod4) ═ 2, and a Slot Number of (Slot Number mod 2) ═ 3 may be assigned to a station group of (AID mod4) ═ 3, where Slot Number represents a Slot Number.

If stations are grouped together, and stations whose AIDs are within a particular range are grouped together, the access point may assign a time slot whose time slot number is within a particular range to the group of stations. For example, stations whose AIDs belong to [1, 10] are grouped into one group, a slot having a slot number of [1, 10] may be allocated to the group of stations, and other slot numbers may be allocated to other stations. It should be understood that the above numerical values are exemplary only, and that the specific ranges may have other numerical ranges or non-continuous numerical values.

Of course, the access point may also configure the slot number allowing the start of data transmission for the station group according to the AID in other manners, which is not illustrated here.

2) Configuring according to the priority of data transmission of the station

The access point may configure more timeslot numbers for the station group with higher transmission rate requirement, and configure fewer timeslot numbers for the station group with lower transmission rate requirement, so as to ensure that the data transmission delay of the station with higher transmission rate requirement is shorter, and the data transmission can be performed faster.

As described above, if the priorities of data transmissions performed by the stations in different station groups are different, more timeslot numbers may be configured for the station group with a higher priority, and less timeslot numbers may be configured for the station group with a lower priority, so as to ensure that the stations in the station group with a higher priority can complete data transmission preferentially and reduce the possibility of collision when the stations in the station group with a higher priority perform data transmission.

Of course, in addition to the above configuration method, the access point may also configure the timeslot number allowed to start data transmission for different station groups in other ways, which is not limited in this embodiment of the present invention.

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

When the above steps are specifically implemented, the access point may directly send a timeslot number that allows the first station to start data transmission to the station; or, if the access point groups the accessed stations and configures a time slot number allowing the start of data transmission for each group of stations, the access point may send, when the first station accesses, the identifier of the station group where the first station is located to the first station, and send, through a broadcast message, the correspondence between the identifier of the station group and the time slot number allowing the start of data transmission by the station in the station group to the station accessing the access point, so as to reduce the signaling resources used.

Alternatively, the access point may identify the group of stations where the station is located through a reserved field in an existing message.

For example, after a station initiates an Association Request (Association Request) to an access point, the access point returns an Association Response message (Association Response) to the station, where the Association Response message includes an AID field for notifying the station of its corresponding AID. In general, when an access point assigns AIDs to stations, the stations are assigned one by one from 1 in the order in which the stations access.

The AID field includes 16 bits, wherein the bits B0-B13 are used to represent the AID of the station, and the two highest bits B14 and B15 are reserved bits, which are set to 1 in the prior art. Thus, the access point may transmit an identification of a station group in which the station is located to the station using the highest two bits B14 and B15 in the AID field. Still taking the aforementioned example of dividing the stations into 4 groups according to the AID, if B14 and B15 are 00, this indicates that the identifier of the station group in which the station is located is 0, that is, the station group whose (AID mod4) is 0; if B14 and B15 are 01, the station group identifier of the station group in which the station is located is 1, that is, the (AID mod4) is 1; if B14 and B15 are 10, the station group identifier of the station group in which the station is located is 2, that is, (AID mod4) ═ 2 station group; if B14 and B15 are 11, this indicates that the station group in which the station is located is identified by 3, that is, the station group whose (AID mod4) ═ 3.

Of course, the access point may also send the identifier of the station group where the station is located to the station through other reserved bits in the existing message; or, the access point may further add some fields in the existing message to send the identifier of the station group where the station is located to the station; or, the access point may add a new message for sending the identifier of the station group where the station is located to the station.

Optionally, the access point may add some fields to the existing message to implement sending the correspondence between the station group identifier and the slot number allowing the stations in the station group to start data transmission to the station.

For example, an AID Group Assignment Information field (i.e., grouping Information of stations) may be added to the Beacon frame, and the subfield included in the field may be as shown in table 2, so as to notify the station of the identity of the station Group where the station is located.

TABLE 2

For another example, the access point may add a Slot Group Assignment (i.e., a correspondence between station Group packet information and station Group identifier and a timeslot number for allowing data transmission to start) field in the Beacon frame, where subfields included in the field may be as shown in table 3, so as to implement sending the correspondence between the station Group identifier and the timeslot number for allowing data transmission to start to the station.

TABLE 3

For another example, after the sites and the timeslot numbers are respectively grouped, an S1 otgroupasistration Information field (i.e., a corresponding relationship between a site group and a timeslot group) is added to the Beacon frame, and subfields included in the field may be as shown in table 4, so as to implement sending the corresponding relationship between the site group and the timeslot group to the sites.

TABLE 4

According to the correspondence between the station group and the timeslot group shown in table 4, taking the example that the stations are divided into two types according to the parity of the AID, it may be defined that a station with an even AID is represented when the first two bits of the 3 rd byte in the table are 00, and a station with an odd AID is represented when the bit is 01; it can be defined that the last two bits of byte 3 are 00 to indicate a time slot group with an even number of time slots, and bit 01 to indicate a time slot group with an odd number of time slots. If the first 4 bits of the third byte are 0101, it may indicate that a station in the station group whose AID is odd is allowed to start data transmission using a slot in the slot group whose slot number is odd.

Step 503, the first station receives the time slot number which is sent by the access point and allows the first station to start data transmission.

If the access point directly sends the timeslot number allowing the first station to start data transmission to the first station, the first station may directly acquire the timeslot number allowing the first station to start data transmission. If the access point groups the sites, the first site determines the time slot number allowing the first site to start data transmission according to the received identifier of the site group where the first site is located and the corresponding relationship between the identifier of the site group and the time slot number allowing the sites in the site group to start data transmission.

Step 504, when the first station needs to perform data transmission, and monitors that the channel is in an idle state, the first station competes for the channel with other stations. Wherein the other stations are one or more other stations except the first station accessing the access point.

After the first station needs to perform data transmission, it needs to monitor whether the channel is occupied first, when the channel is occupied by other stations, the first station cannot perform data transmission, and when the channel is in an idle state, the first station needs to contend for the channel again to perform data transmission.

In general, a certain time interval exists between two data transmissions, and the first station may perform data transmission only after monitoring that the time length during which the channel is idle reaches the preset time length, that is, the time length during which the channel is idle reaches the preset time length, and then considers that the channel is idle. The preset duration may be a duration of one DIFS.

In some embodiments, after the first station monitors that the channel is in the idle state, it may further select a backoff delay time duration from the contention window, and start to count down, where after the backoff delay time duration reaches, that is, when the timer clears zero, the first station successfully contends for the channel. And if the channel is occupied by other stations before the backoff delay time length reaches, the first station suspends the timer, and continues to count down when waiting for the channel to be in the idle state again.

As described above, the size of the contention window is preset, and the station may randomly select one backoff delay time duration from the contention window, or may naturally select the backoff delay time duration according to a certain rule, for example, the station with a higher priority selects a shorter backoff delay time duration, and the station with a lower priority selects a longer backoff delay time duration. When data transmission conflict occurs, the contention window may be expanded, and when data transmission is successful, the size of the contention window may be restored to the original size.

Because the first station selects a back-off delay time length after monitoring that the channel is in an idle state, even if the stations which are allowed to use the same time slot to carry out data transmission are divided into the same station group and simultaneously need to carry out data transmission, the sequence of carrying out data transmission is determined according to the length of the selected back-off delay time length, and the possibility of data transmission conflict is further reduced.

Step 505, when the first station successfully competes for the channel, determining whether the current timeslot is a timeslot corresponding to a timeslot number that allows the first station to start data transmission. If yes, go to step 506; otherwise, go to step 507.

As described above, the first station acquires, from the access point, the time slot numbers that allow the first station to start data transmission, and the first station determines whether the first station is allowed to start data transmission in the current time slot according to the time slot numbers.

Step 506, if the first station determines that the current time slot is the time slot corresponding to the time slot number allowing the first station to start data transmission, the first station performs data transmission to the access point in the channel occupied by the current time slot.

Step 507, if the first station determines that the current time slot is not the time slot corresponding to the time slot number allowing the first station to start data transmission, the first station occupies the channel to immediately perform data transmission when waiting for the time slot corresponding to the time slot number allowing the first station to start data transmission.

In some embodiments, the first station also monitors whether the channel is idle at any time during the waiting period, and if the first station monitors that other stations occupy the channel for data transmission during the waiting period, the first station still needs to wait for the channel to be occupied for data transmission after the data transmission of other stations is finished, and when the idle time of the channel reaches a preset time and a time slot allowing the first station to start data transmission comes, the first station occupies the channel to start data transmission.

In some other embodiments, the first station may not monitor the channel during the waiting period, and when the time slot allowing the first station to start data transmission arrives, monitor whether the channel is in an idle state, if the channel is in the idle state, the first station occupies the channel to perform data transmission, otherwise, the first station still needs to wait, and when the channel is in the idle state and the time slot allowing the first station to perform data transmission arrives, the channel is occupied to start data transmission.

In the above embodiment of the present invention, the access point configures, for the first station, the timeslot number that allows the first station to start occupying the channel for data transmission, so that the first station starts data transmission at the timeslot corresponding to the timeslot number that is allowed to start data transmission, and thereby reducing occurrence of data transmission failure caused by multiple stations occupying the channel for transmitting data at the same time. In addition, the stations accessing the access point can be grouped, for example, the stations are grouped according to the priority of data transmission, and the same time slot numbers allowing the start of data transmission are configured for a group of stations, so that the situation that a plurality of stations conflict when occupying the same channel to transmit data is further reduced while the transmission efficiency is not influenced.

In order to more clearly understand the point-to-multipoint channel allocation method provided by the embodiment of the present invention, a specific embodiment is described below.

Examples 1,

The access point groups stations according to the parity of the AIDs of the stations, namely, the stations with odd AIDs are divided into a group, and the stations with even AIDs are divided into a group. The access point configures a time slot with an odd number of time slots for stations in a station group with an odd AID, namely the stations with the odd AID are allowed to occupy a channel for data transmission on the time slot corresponding to the time slot with the odd number of time slots; the access point configures a time slot with an even slot number for a station in a station group with an even AID, that is, the station with the even AID is allowed to occupy a channel for data transmission on a time slot corresponding to the time slot with the even slot number.

The access point broadcasts the station grouping information and the available time slot numbers configured for each station group to all stations through the Beacon frame, so that each station can acquire the available time slot numbers of the station.

The access point may also set the period of the Beacon frame to 100ms, and set the duration SlotTime of one slot to the minimum slot duration of 9us, that is, one Beacon frame period is divided into 11112 slots, and 14 bits may be used to represent one slot number. The access point may send the division rule of the time slot to all stations through a broadcast message.

The AID of station 1(STA1) is 1, and the AID of station 2(STA2) is 2. As shown in fig. 6, STA1 and STA2 need to perform data transmission at time T1 at the same time, and after it is monitored that the channel idle duration reaches the DIFS duration (assuming that the DIFS duration is a duration of 2 slots), a backoff delay duration, which is 5 slots and 3 slots, is randomly selected from the contention window, and a timer is started to count down. Because the back-off delay time of STA2 is short, the back-off is cleared first, the timeslot number corresponding to the current timeslot is 5, STA2 is only allowed to start data transmission on the timeslot with the even timeslot number, so STA2 cannot start data transmission at this time and needs to wait, when the timeslot with timeslot number 6 arrives, STA2 monitors that the channel is still idle, so STA2 occupies the channel on the timeslot corresponding to timeslot number 6 to start data transmission. At this point, STA1 listens that the channel is occupied, so STA1 suspends the countdown, which leaves 1 slot. After STA2 finishes data transmission, STA1 keeps counting down after the monitored channel idle duration reaches DIFS duration, the timer is cleared after 1 timeslot, the timeslot number of the current timeslot is 13, STA1 is allowed to start data transmission in the current timeslot, so STA1 starts to occupy the channel for data transmission.

The STA1 and the STA2 need to perform data transmission again at the time of T2, and after it is monitored that the channel idle duration reaches the DIFS duration, a backoff delay duration, which is 4 slots and 8 slots, is randomly selected from the contention window, and a timer is started to count down. Because the back-off delay time of STA1 is short, the back-off is cleared first, the timeslot number corresponding to the current timeslot is 6, STA1 is only allowed to start data transmission on the timeslot with the odd timeslot number, so STA1 cannot start data transmission at this time and needs to wait, when the timeslot with timeslot number 7 arrives, STA1 monitors that the channel is still idle, so STA1 occupies the channel on the timeslot corresponding to timeslot number 7 to start data transmission. At this point, STA2 listens that the channel is occupied, so STA2 suspends the countdown, which leaves 3 slots. After the STA1 finishes data transmission, after the STA2 monitors that the channel idle time reaches the DIFS time, the STA continues to count down, the timer is cleared after 3 time slots, the time slot number of the current time slot is 16, the STA2 is allowed to start data transmission in the current time slot, and therefore the STA2 starts to occupy the channel for data transmission.

Examples 2,

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

The access point groups the stations according to the priority of the stations for data transmission, that is, the stations with high priority are grouped into one group, and the stations with low priority are grouped into one group. The access point allocates the time slots with the time slot numbers of 0-14 to the station group with high priority, and allocates the time slots corresponding to other time slot numbers to the station group with low priority.

STA1 is a high priority station and STA2 and STA3 are low priority stations. As shown in fig. 7, STA1, STA2, and STA3 need to perform data transmission at time T1, and after it is monitored that the channel idle duration reaches the DIFS duration (assuming that the DIFS duration is a duration of 2 slots), a backoff delay duration is randomly selected from the contention window, which is 2 slots, 5 slots, and 7 slots, and a timer is started to count down. Because the backoff delay time of STA1 is short, the countdown is first performed to zero, the timeslot number corresponding to the current timeslot is 4, and STA1 is allowed to occupy the channel for data transmission in the current timeslot, STA1 occupies the channel for data transmission in the timeslot corresponding to timeslot number 4. At this time, STA2 and STA3 listen that the channel is occupied, so STA2 and STA3 pause the countdown, which leaves 3 slots and 5 slots, respectively. After STA1 finishes data transmission, STA2 and STA3 continue to count down after the idle duration of the monitored channel reaches the DIFS duration, the timer is cleared after 3 time slots, the time slot number of the current time slot is 14, the time slot corresponding to the time slot number 14 is the time slot available for the high-priority station, STA2 is the low-priority station, so STA2 cannot start data transmission at the current time slot, and needs to wait, when the time slot with the time slot number of 15 arrives, STA2 monitors that the channel is still in an idle state, so STA2 occupies the channel at the time slot corresponding to the time slot number 15 to start data transmission. At this point, STA3 listens that the channel is occupied, so STA3 suspends the countdown, which leaves 1 slot. After STA2 finishes data transmission, STA3 keeps counting down after the monitored channel idle duration reaches DIFS duration, the timer is cleared after 1 timeslot, the timeslot number of the current timeslot is 21, STA3 can start data transmission in the current timeslot, so STA3 starts to occupy the channel for data transmission.

Based on the same technical concept, the embodiment of the invention also provides a station, which is used for realizing that the point-to-multipoint channel allocation method provided by the embodiment of the invention occupies a channel for data transmission.

Referring to fig. 8, which is one of schematic structural diagrams of a first station provided in the embodiment of the present invention, as shown in the figure, the first station includes: the monitoring module 801, the competition module 802, the determining module 803, and the transmitting module 804 may further include a receiving module 805.

The monitoring module 801 is configured to monitor whether a channel is in an idle state.

A contention module 802, configured to contend for a channel with another station after the monitoring module 801 monitors that the channel is in an idle state. Wherein, the other stations are one or more other stations except the first station which are accessed to the same access point.

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

A transmission module 804, configured to perform data transmission to the access point on a channel occupied by the current time slot if the determination module 803 determines that the current time slot is the time slot corresponding to the time slot number allowing the first station to start data transmission; otherwise, when waiting for the time slot corresponding to the time slot number allowing the first station to start data transmission, the channel is occupied to transmit data to the access point.

The channel is a channel commonly used by a plurality of stations accessing the access point.

Optionally, the timeslot number allowing 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 an identifier of a station group and a time slot number allowing a station in the station group to start data transmission. And the first station takes the time slot number corresponding to the identifier of the station group in which the first station is positioned in the corresponding relation as the time slot number allowing the first station to start data transmission.

Optionally, the station groups are divided according to the priorities of the stations for data transmission, and the number of the time slot numbers that the stations in the station group with the higher priority are allowed to start data transmission is greater than or equal to the number of the time slot numbers that the stations in the station group with the lower priority are allowed to start data transmission.

Optionally, the station group may be further divided according to the numerical value of the association identifier AID of the station.

Optionally, the competition module 802 is specifically configured to: determining a backoff delay time length which is selected from a plurality of preset delay time lengths; and when the duration of the idle state of the channel reaches the backoff delay duration, the first station successfully competes to the channel.

Optionally, when the monitoring channel is in an idle state, the monitoring module 801 is specifically configured to: and determining that the channel is in an idle state if the time length of the channel in the idle state reaches the preset time length.

Referring to fig. 9, a second schematic structural diagram of the first station provided in the embodiment of the present invention is shown, and as shown in the drawing, the first station includes: a processor 901, a memory 902, a transceiver 903, and a bus interface.

The transceiver 903 is used for receiving and transmitting 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 in performing operations.

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

when the channel is monitored to be in an idle state, the channel competes with other stations; when the channel is successfully contended, determining whether the current time slot is a time slot corresponding to a time slot number allowing the first station to start data transmission; if the current time slot is determined to be the time slot corresponding to the time slot number allowing the first station to start data transmission, data transmission is performed to the access point through the transceiver 903 on the occupied channel of the current time slot, otherwise, when the time slot corresponding to the time slot number allowing the first station to start data transmission arrives, the occupied channel performs data transmission to the access point through the transceiver 903. And the other stations are one or more other stations except the first station which are accessed to the same access point.

The channel is a channel which is used by a plurality of stations accessed to the access point in a competition mode.

Optionally, the processor 901 is specifically configured to receive, by the transceiver 903, a broadcast message sent by an access point, where the broadcast message includes a correspondence between an identifier of a station group and a time slot number allowing a station in the station group to start data transmission; and taking the time slot number corresponding to the identifier of the station group where the station belongs in the corresponding relation as the time slot number allowing the first station to start data transmission.

Optionally, the processor 901 is specifically configured to, when contending for a channel: determining a backoff delay time length which is selected from a plurality of preset delay time lengths; and when the duration of the idle state of the channel reaches the backoff delay duration, the first station successfully competes to the channel.

Optionally, the processor 901, when monitoring whether the channel is in an idle state, is specifically configured to: and determining that the channel is in an idle state if the time length of the channel in the idle state reaches the preset time length.

Based on the same technical concept, the embodiment of the invention also provides an access point, which is used for realizing the method embodiment.

Referring to fig. 10, which 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 determination module 1001 and a sending module 1002.

The determining module 1001 is configured to determine a timeslot number at which a first station that is allowed to access the access point starts data transmission.

A sending module 1002, configured to send the determined time slot number to the first station, so that the first station competes for the channel with other stations after monitoring that the channel is in an idle state, and occupies the channel to start data transmission to the access point when a time slot corresponding to the time slot number allowed to start data transmission arrives after successfully competing for the channel. Wherein the other stations are one or more other stations except the first station which are accessed to the access point.

Optionally, the determining module 1001 is specifically configured to: grouping stations accessing the access point; each station group is assigned a time slot number that allows the stations in the corresponding station group to begin data transmission.

The sending module 1002 is specifically configured to: and sending a broadcast message, wherein the broadcast message comprises the corresponding relation between the identifier of the site group and the time slot number allowing the sites in the site group to start data transmission.

Optionally, the station groups are divided according to priorities of the stations for data transmission, and the number of the time slot numbers that the stations in the station group with the higher priority are allowed to start data transmission is greater than or equal to the number of the time slot numbers that the stations in the station group with the lower priority are allowed to start data transmission.

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

The transceiver 1103 is used for receiving and transmitting 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 in performing operations.

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

the time slot number allowing the start of data transmission is determined for the accessed first station, and then the determined time slot number is sent to the first station through the transceiver 1103, so that the first station competes with other stations for a channel after monitoring that the channel is in an idle state, and occupies the channel to start transmitting data to the access point when the time slot corresponding to the time slot number allowing the start of data transmission arrives after successfully competing for the channel. The channel is a channel commonly used by a plurality of stations accessing the access point. Wherein the other stations are one or more other stations except the first station which are accessed to the access point.

Optionally, the processor 1101, when determining a timeslot number allowing starting of data transmission for the accessed first station, is specifically configured to: grouping stations accessing the access point; allocating a time slot number for each station group, wherein the time slot number allows the station in the corresponding station group to start data transmission; a broadcast message is sent via the transceiver 1103, where the broadcast message includes a correspondence between the identifier of the site group and a time slot number allowing the sites in the site group to start data transmission.

Alternatively, the station groups may be divided according to the priorities of the stations for data transmission, and the number of the time slot numbers that the stations in the station group with a high priority are allowed to start data transmission is greater than or equal to the number of the time slot numbers that the stations in the station group with a low priority are allowed to start data transmission.

Based on the same technical concept, the embodiment of the invention also provides a point-to-multipoint system, which is used for reducing the situation that data transmission conflicts occur when a plurality of stations compete for a channel. The system comprises an access point as described above, and N stations as described above, where N is an integer greater than 1.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A point-to-multipoint channel allocation method, applied in a scenario where a plurality of stations access to an access point, comprising:

after monitoring that a channel is in an idle state, a first station competes for the channel with other stations; the other stations are one or more other stations except the first station which are accessed to the access point;

when the first station successfully competes to the channel, determining whether the current time slot is a time slot corresponding to a time slot number allowing the first station to start data transmission;

if the first station determines that the current time slot is the time slot corresponding to the time slot number allowing the first station to start data transmission, the first station occupies the channel in the current time slot to transmit data to the access point; otherwise, when waiting for the time slot corresponding to the time slot number allowing the first station to start data transmission, occupying the channel to transmit data to the access point.

2. The method of claim 1, wherein the number of time slots during which the first station is allowed to begin data transmission is sent by the access point to the first station.

3. The method of claim 2, wherein prior to the first station contending for the channel with other stations, further comprising:

the first station receives a broadcast message sent by the access point, wherein the broadcast message comprises a corresponding relation between the identifier of the station group and a time slot number allowing the station in the station group to start data transmission;

and the first station takes the time slot number corresponding to the identifier of the station group in which the first station is positioned in the corresponding relation as the time slot number allowing the first station to start data transmission.

4. The method of claim 3, wherein the station groups are divided according to priorities of the stations for data transmission, and a number of time slot numbers for which the stations in the station group with a high priority are allowed to start data transmission is greater than or equal to a number of time slot numbers for which the stations in the station group with a low priority are allowed to start data transmission.

5. The method of claim 3, wherein the group of stations are partitioned according to a numerical value of an association identifier AID of the station.

6. The method of claim 1, wherein the first station contending for the channel with other stations, comprising:

the first station determines a backoff delay time length which is selected from a plurality of preset delay time lengths;

and when the time length of the channel idle state reaches the backoff delay time length, the first station successfully competes to the channel.

7. The method of claim 1, wherein the first station listens to the channel in an idle state, comprising:

and the first station monitors that the time length of the channel in the idle state reaches a preset time length.

8. A point-to-multipoint channel allocation method, applied in a scenario where a plurality of stations access to an access point, comprising:

the method comprises the steps that an access point determines a time slot number allowing a first station accessing the access point to start data transmission;

the access point sends the determined time slot number to the first site, so that the first site competes for the channel with other sites after monitoring that the channel is in an idle state, and occupies the channel to start data transmission to the access point when a time slot corresponding to the time slot number allowed to start data transmission arrives after successfully competing for the channel; the other stations are one or more other stations except the first station which are accessed to the access point.

9. The method of claim 8, wherein the access point determining a slot number to allow a first station accessing the access point to begin data transmission comprises:

the access point groups stations accessing the access point;

the access point allocates a time slot number for each station group, wherein the time slot number allows the station in the corresponding station group to start data transmission;

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

and the access point sends a broadcast message, wherein the broadcast message comprises the corresponding relation between the identifier of the site group and the time slot number allowing the sites in the site group to start data transmission.

10. The method of claim 9, wherein the station groups are divided according to priorities of the stations for data transmission, and a number of slot numbers for which the stations in the station group with a high priority are allowed to start data transmission is greater than or equal to a number of slot numbers for which the stations in the station group with a low priority are allowed to start data transmission.

11. A station, for use in a scenario where multiple stations access an access point, the station being a first station, the method comprising:

the monitoring module is used for monitoring whether the channel is in an idle state;

the competition module is used for competing the channel with other stations after the monitoring module monitors that the channel is in an idle state; the other stations are one or more other stations except the first station which are accessed to the access point;

a determining module, configured to determine, when the contention to the channel succeeds, whether a current timeslot is a timeslot corresponding to a timeslot number that allows the first station to start data transmission;

12. The station of claim 11, wherein the number of time slots that the first station is allowed to begin data transmission is sent by the access point to the first station.

13. The station of claim 12, further comprising: a receiving module to:

receiving a broadcast message sent by the access point, wherein the broadcast message comprises a corresponding relation between the identifier of the site group and a time slot number allowing the sites in the site group to start data transmission;

and taking the time slot number corresponding to the identifier of the station group where the station group is located in the corresponding relation as the time slot number allowing the first station to start data transmission.

14. The station of claim 13, wherein the station groups are divided according to priorities of the stations for data transmission, and a number of time slot numbers for which the stations in the station group with a high priority are allowed to start data transmission is greater than or equal to a number of time slot numbers for which the stations in the station group with a low priority are allowed to start data transmission.

15. The station of claim 13, wherein the group of stations is partitioned according to a numerical value of an association identifier AID of the station.

16. The station according to claim 11, wherein the contention module is specifically configured to:

determining a backoff delay time length which is selected from a plurality of preset delay time lengths;

17. The station of claim 11, wherein the monitoring module, when monitoring whether the channel is in an idle state, is specifically configured to:

and determining that the channel is in an idle state if the time length of the channel in the idle state reaches the preset time length.

18. An access point, for use in a scenario where multiple stations access to the access point, comprising:

a determining module, configured to determine a timeslot number at which a first station that is allowed to access the access point starts data transmission;

19. The access point of claim 18, wherein the determining module is specifically configured to:

grouping stations accessing the access point; allocating a time slot number for each station group, wherein the time slot number allows the station in the corresponding station group to start data transmission;

the sending module is specifically configured to:

and sending a broadcast message, wherein the broadcast message comprises the corresponding relation between the identifier of the site group and the time slot number allowing the sites in the site group to start data transmission.

20. The access point of claim 19, wherein the station groups are divided according to priorities of the stations for data transmission, and a number of time slot numbers for which the stations in the station group with a higher priority are allowed to start data transmission is greater than or equal to a number of time slot numbers for which the stations in the station group with a lower priority are allowed to start data transmission.

21. A point-to-multipoint system comprising one access point according to any one of claims 18 to 20 and N stations according to any one of claims 11 to 17, wherein N is an integer greater than 1.