Patent Description:
With the rapid development of communications technologies, a WLAN (Wireless Local Area Network, wireless local area network) technology based on the IEEE <NUM> standard has been considerably developed and widely applied. A WLAN network may include multiple APs (Access Point, access point) and multiple STAs (Station, station), where each AP may be associated with multiple STAs, and each AP may transmit, by using a radio channel, wireless local area network data with a STA that is associated with the AP.

A current method for transmitting wireless local area network data is specifically: when the AP sends wireless local area network data to a STA associated with the AP, the AP listens on a radio channel, and when the radio channel is not occupied in a period of time, the AP accesses the radio channel, and acquires a right to use of the radio channel. The AP encapsulates wireless local area network data that needs to be transmitted, into a PPDU (PLCP protocol data unit, PLCP protocol processing unit), and sends the PPDU to the STA. When a STA associated with the AP sends wireless local area network data to the AP, the STA listens on the radio channel, and when the radio channel is not occupied in a period of time, the STA accesses the radio channel, and acquires the right to use of the radio channel. The STA encapsulates wireless local area network data that needs to be transmitted, into a PPDU, and sends the PPDU to the AP.

As shown in <FIG>, the first row of <FIG> shows a conventional PPDU format, and the second row and the third row of <FIG> show a PPDU frame format of <NUM>. <FIG> shows a PPDU frame format of <NUM>. A STA may encapsulate, by using the frame format of <FIG>, wireless local area network data into a PPDU and send the PPDU to an AP. Certainly, an AP may also encapsulate, by using the PPDU frame format of <FIG>, wireless local area network data into a PPDU and send the PPDU to a STA. L-STF, HT-STF, and HT-GF-STF are short training fields, L-LTF, HT-LTF1, HT-LTF, and VHT-LTF are long training fields, L-SIG, HT-SIG, VHT-SIG-A, and VHT-SIG-B are signaling fields, and Data is a data field.

During the implementation of the present invention, the inventors find that the prior art has at least the following problems:.

Because a WLAN network uses a free unauthorized frequency band, and uses a contention-based access mechanism to acquire a right to use of a radio channel, and when a STA/an AP acquires the right to use of the radio channel, wireless local area network data is transmitted between the AP and the STA in a one-to-one relationship, and the wireless local area network data cannot be transmitted between the AP and the STA in a one-to-many or between the STA and the AP in a many-to-one relationship, which reduces spectrum utilization and network use efficiency.

To improve spectrum utilization and network use efficiency, embodiments of the present invention provide a method and an apparatus for transmitting wireless local area network data. The technical solutions are specified in the independent claims appended hereto and with further aspects specified in the dependent claims.

To describe the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings required for describing the embodiments.

To make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the embodiments of the present invention in detail with reference to the accompanying drawings.

Considering the problem of the prior art, in the embodiments of the present invention, when a right to use of a radio channel is acquired, an AP constructs a radio frame, where the radio frame includes a preamble part, a control domain, and a data domain. The data domain may include at least one downlink data domain, and the downlink data domain includes multiple radio resource blocks, where each STA associated with the AP has a corresponding radio resource block. The AP may transmit, on a radio resource block corresponding to each STA in the downlink data domain, wireless local area network data to a STA associated with the AP, improving spectrum utilization and network use efficiency.

With reference to multiple embodiments, the following describes solutions and effects of the present invention in more detail by using a next-generation WLAN as an example. In the following embodiments, a quantity of STAs associated with the AP may be one, or may be multiple.

<FIG> is an apparatus for transmitting wireless local area network data according to an embodiment of the present invention. Referring to <FIG>, the apparatus includes:.

Both the preamble part and the control domain are sent in an orthogonal frequency division multiplexing OFDM manner compatible with the existing Institute of Electrical and Electronics Engineers IEEE <NUM> standard, and the data domain is sent in an orthogonal frequency division multiple access OFDMA manner.

The preamble part is a preamble part compatible with the existing IEEE802. <NUM>, and the preamble part includes a legacy-short training field L-STF, a legacy-long training field L-LTF, and a legacy-signaling field L-SIG, where the L-STF is used to synchronize the STA associated with the AP with the AP, and the L-LTF is used to enable the STA associated with the AP to perform channel estimation, to acquire, by means of coherent reception, information that is related to duration of the radio frame and carried in the L-SIG.

Further, a length LENGTH data domain in the L-SIG domain carries a value related to the duration of the radio frame, and the duration, corresponding to the value, of the radio frame is greater than or equal to actual duration of the radio frame.

Optionally, the apparatus further includes:
an increasing module, configured to increase transmit power of the preamble part of the radio frame, so that a STA not associated with the AP and another AP receive the preamble part of the radio frame, and within reserved duration, the STA not associated with the AP and the another AP no longer transmit wireless local area network data by using the radio channel, where the reserved duration is duration within which the AP owns the right to use of the radio channel.

Further, the control domain includes: configuration information of an uplink/downlink data domain in the radio frame, an OFDMA modulation parameter used by the data domain, and radio resource allocation indication information for the STA associated with the AP.

The configuration information of the uplink/downlink data domain includes: a quantity of uplink data domains, a quantity of downlink data domains, and transformation information between the uplink data domain and the downlink data domain.

Optionally, the OFDMA modulation parameter used by the data domain includes: channel bandwidth of a system, a used cyclic prefix CP length, a fast Fourier transformation FFT order, and a quantity of available subcarriers.

The radio resource allocation indication information for the STA associated with the AP includes: a first radio resource indication, where the first radio resource indication is used to indicate a radio resource block corresponding to a second radio resource indication used by each scheduled STA to transmit data, or the first radio resource indication is used to indicate a radio resource block used by each scheduled STA to transmit data.

The first radio resource indication includes: a size and a position of a radio resource block indicated by the first radio resource indication, and a modulation and coding scheme and/or a multiple-input multiple-output MIMO transmission manner used on the radio resource block.

Further, the apparatus further includes:
a first receiving module, configured to: when the data domain includes an uplink data domain, receive, in the uplink data domain included in the data domain, according to the control domain, wireless local area network data sent by the STA associated with the AP.

In this embodiment of the present invention, when a right to use of a radio channel is acquired, an AP may construct a radio frame, where a data domain of the radio frame may include at least one downlink data domain, the downlink data domain includes multiple radio resource blocks, and each STA has a corresponding radio resource block. The AP may send, on a radio resource block corresponding to a STA in the downlink data domain, wireless local area network data to a STA associated with the AP. When the data domain of the radio frame includes an uplink data domain, the uplink data domain also includes multiple radio resource blocks, and each STA has a corresponding radio resource block. The STA associated with the AP may send, on a radio resource block corresponding to the STA, wireless local area network data to the AP. Because the AP may be associated with multiple STAs, the wireless local area network data can be transmitted between the AP and the STA in a one-to-many or many-to-one relationship, improving spectrum utilization and network use efficiency.

The preamble part is a preamble part compatible with the existing Institute of Electrical and Electronics Engineers IEEE802. <NUM>, and the preamble part includes a legacy-short training field L-STF, a legacy-long training field L-LTF, and a legacy-signaling field L-SIG; and
accordingly, the apparatus further includes:.

The control domain includes: configuration information of an uplink/downlink data domain in the radio frame, an OFDMA modulation parameter used by the data domain, and radio resource allocation indication information for the STA associated with the AP.

Further, the apparatus further includes:
a third sending module, configured to: when the data domain includes an uplink data domain, send, in the uplink data domain included in the data domain, according to the control domain, wireless local area network data to the AP associated with the STA.

<FIG> is a method for transmitting wireless local area network data according to an embodiment of the present invention. Referring to <FIG>, the method includes:.

Step <NUM>: When a right to use of a radio channel is acquired, an access point AP constructs a radio frame, where the radio frame includes at least a preamble part, a control domain, and a data domain, and the data domain includes at least one downlink data domain.

Step <NUM>: The AP sends the preamble part and the control domain to a station STA associated with the AP.

Step <NUM>: The AP sends, in a downlink data domain of the radio frame, wireless local area network data to the STA associated with the AP.

Optionally, the method further includes:
increasing, by the AP, transmit power of the preamble part of the radio frame, so that a STA not associated with the AP and another AP receive the preamble part of the radio frame, and within reserved duration, the STA not associated with the AP and the another AP no longer transmit wireless local area network data by using the radio channel, where the reserved duration is duration within which the AP owns the right to use of the radio channel.

Further, the OFDMA modulation parameter used by the data domain includes: channel bandwidth of a system, a used cyclic prefix CP length, a fast Fourier transformation FFT order, and a quantity of available subcarriers.

Optionally, the method further includes:
when the data domain includes an uplink data domain, receiving, by the AP, in the uplink data domain included in the data domain, according to the control domain, wireless local area network data sent by the STA associated with the AP.

The preamble part is a preamble part compatible with the existing Institute of Electrical and Electronics Engineers IEEE802. <NUM>, and the preamble part includes a legacy-short training field L-STF, a legacy-long training field L-LTF, and a legacy-signaling field L-SIG; and
accordingly, after the receiving, by a station STA, a preamble part and a control domain of a radio frame that are sent by an access point AP associated with the STA, the method further includes:.

A length LENGTH data domain in the L-SIG domain carries a value related to the duration of the radio frame, and the duration, corresponding to the value, of the radio frame is greater than or equal to actual duration of the radio frame.

Optionally, the method further includes:
when the data domain includes an uplink data domain, sending, by the STA, in the uplink data domain included in the data domain, according to the control domain, wireless local area network data to the AP associated with the STA.

<FIG> is a method for transmitting wireless local area network data according to an embodiment of the present invention. Referring to <FIG>, the method includes:
Step <NUM>: When a right to use of a radio channel is acquired, an AP constructs a radio frame, where the radio frame includes at least a preamble part, a control domain, and a data domain, and the data domain includes at least one downlink data domain.

A specific operation of acquiring a right to use of a radio channel may be: listening on the radio channel, and detecting energy of the radio channel. When it is detected that the energy of the radio channel is less than a preset threshold, and it is detected that n NAV (Network Allocation Vector, network allocation vector) is not set, it is determined that the radio channel is not occupied at a current moment. After a random backoff time, if the radio channel is still not occupied, access is made to the radio channel, to acquire the right to use of the radio channel.

Both the AP and a STA associated with the AP may acquire the right to use of the radio channel. After the STA associated with the AP acquires the right to use of the radio channel, the STA associated with the AP sends a notification message to the AP to notify the AP.

Further, when the right to use of the radio channel is acquired, the AP may further construct a reserved control frame according to an address of the AP and reserved duration, where the reserved duration is duration during which the AP owns the right to use of the radio channel. The AP broadcasts the reserved control frame, to state that the AP and the STA associated with the AP use the radio channel within nearest reserved duration after a current time.

The AP broadcasts the reserved control frame, so that after receiving the reserved control frame, a STA not associated with the AP and another AP may no longer acquire the right to use of the radio channel within the nearest reserved duration after the current time, avoiding impact caused on the AP and the STA associated with the AP by the STA not associated with the AP and the another AP.

It should be noted that the reserved duration may be preset, or may be configured by the AP, which is not specifically limited in this embodiment of the present invention.

Optionally, when the right to use of the radio channel is acquired, the AP may further group the reserved duration as at least one radio frame. In the at least one radio frame obtained by means of grouping, duration of each radio frame and duration of a SIFS (Short Inter-Frame Space, short inter-frame space) are pre-configured. The duration of the SIFS is a time interval between two neighboring radio frames. When a radio frame ends, the AP continues to listen to the duration of the SIFS of the radio channel, and if the radio channel is not occupied within the duration of the SIFS, the AP constructs a next radio frame.

As shown in <FIG>, the AP and the STA associated with the AP may acquire the right to use of the radio channel in a contention window in a CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance, carrier sense multiple access/collision avoidance) manner. When the right to use of the radio channel is acquired, the AP may broadcast the reserved control frame in a reserved channel in <FIG>, to reserve the radio channel. After the AP reserves the radio channel, the AP enters a scheduling window, where a time length of the scheduling window is reserved duration. The AP may group the reserved duration as at least one radio frame.

In this embodiment of the present invention, not only the AP may construct the radio frame according to a quantity of STAs associated with the AP, but also the AP may construct the radio frame according to a service between the AP and the STA associated with the AP. Certainly, the AP may also construct the radio frame in another manner, which is not specifically limited in this embodiment of the present invention.

The radio frame includes at least a preamble part, a control domain, and a data domain, and the data domain includes at least one downlink data domain. When the data domain not only includes a downlink data domain, but also includes an uplink data domain, a TTG (Transmit/receive Transition Gap, Transmit/receive Transition Gap) is set between the uplink data domain and the downlink data domain, for example, a size of the TTG may be <NUM>. As shown in the bottom half of <FIG>, LP is a preamble part, FC is a control domain, DL is a downlink data domain, and UL is an uplink data domain. DL, UL, and TTG in <FIG> construct the data domain of the radio frame.

Further, a sum of quantities of uplink data domains and downlink data domains in the data domain is <NUM> at most.

The preamble part is a preamble part compatible with the existing IEEE802. <NUM>, and the preamble part includes an L-STF (Legacy-Short Training Field, legacy-short training field), an L-LTF (Legacy-Long Training Field, legacy-long training field), and an L-SIG (Legacy-Signal Field, legacy-signaling field), where the L-STF is used to synchronize a STA associated with an AP with the AP, and the L-LTF is used to enable the STA associated with the AP to perform channel estimation, to acquire, by means of coherent reception, information that is related to duration of the radio frame and carried in the L-SIG.

The foregoing mentioned existing IEEE802. <NUM> may be IEEE802.11a, IEEE802. <NUM>, IEEE802.11n or IEEE802.11ac.

A LENGTH (that is, length) data domain in the L-SIG domain carries a value related to the duration of the radio frame, and the value is greater than or equal to actual duration of the radio frame.

Further, the L-SIG domain further includes a rate. A time length may be calculated according to the rate and the length. The rate and the length that are included in the L-SIG domain may be used to configure group information of a receiver.

For example, if the value is <NUM>, it is calculated according to the rate included in the L-SIG domain that the data <NUM> is corresponding to <NUM>, and <NUM> is duration of the control domain and the data domain. If the duration of the preamble part is <NUM>, maximum duration of the radio frame is <NUM>.

The quantities of uplink data domains and downlink data domains in the radio frame may be configured, and duration of each uplink/downlink data domain is pre-configured, for example, the duration of each uplink/downlink data domain may be <NUM>. If an uplink data domain exists in the radio frame, a time interval, that is, a TTG, is needed for transformation between the downlink data domain and the uplink data domain, where duration of the TTG may be <NUM>, and the TTG may ensure the transformation between the downlink data domain and the uplink data domain. The duration of the control domain is <NUM> or <NUM>. When the duration of the control domain is <NUM>, the control domain includes <NUM> OFDM (Orthogonal Frequency Division Multiplexing, orthogonal frequency division multiplexing) symbols, and when the duration of the control domain is <NUM>, the control domain may include <NUM> OFDM symbols, where the OFDM symbol herein is set by using an OFDM parameter of <NUM>. It is set according to the foregoing parameter that, when the duration of the control domain is <NUM>, a maximum duration of a radio frame is <NUM>; or when the duration of the control domain is <NUM>, a maximum duration of a radio frame is <NUM>.

As shown in <FIG>, the L-SIG in the preamble part may represent a packet length by using <NUM> bits, which means that a maximum packet length that can be represented by the L-SIG field is limited to <NUM> bits. A lowest MCS (Modulation and Coding Scheme, modulation and coding scheme) represented by a rate Rate part is BPSK (Binary Phase Shift Keying, binary phase shift keying) modulation. By using the BPSK modulation and the packet length represented by <NUM> bits, maximum duration of a next packet may be calculated. A tail Tail is used to clear a channel coder, and a register of a decoder.

The configuration information of the uplink/downlink data domain may include: a quantity of uplink data domains, a quantity of downlink data domains, and transformation information between the uplink data domain and the downlink data domain.

The quantities of uplink data domains and downlink data domains in the radio frame may be configured according to a service between the AP and the STA associated with the AP. Certainly, the AP may further select a configuration manner from multiple pre-configured configuration manners according to the service between the AP and the STA associated with the AP. For example, as shown in the following Table <NUM>, Table <NUM> shows multiple configuration manners, where D in Table <NUM> represents a downlink data domain, and U represents an uplink data domain; and Table <NUM> further shows a size of a value in LENGTH included in an L-SIG corresponding to each configuration manner. Because the duration of the control domain may be <NUM>, or may be <NUM>, Table <NUM> shows a size of a value in LENGTH1 corresponding to <NUM>, and shows a size of a value in LENGTH2 corresponding to <NUM>.

Further, positions of the uplink data domains and the downlink data domains in the radio frame may also be configured.

The OFDMA modulation parameter used by the data domain may include: channel bandwidth of a system, a used CP (Cyclic Prefix, cyclic prefix) length, an FFT (Fast Fourier Transformation, fast Fourier transformation) order, and a quantity of available subcarriers.

The used CP length may also be configured according to a scenario in which the AP is deployed. When scenarios are quite different, channel conditions are also quite different. For example, the AP may be deployed indoors or outdoors. Different channel conditions also require different CP lengths. Selection of a CP length is a compromise result of resource overheads and system performance. When an indoor channel exists between an AP and a STA, multipath spread is small; and in this case, using a relatively long CP may cause reduction of resource utilization. When an outdoor channel or an outdoor to indoor channel exists between an AP and a STA, multipath spread is large; and in this case, using a relatively short CP may cause reduction of system performance. Therefore, a fixed CP length may fail to meet deployment of all or most of scenarios. The AP needs to indicate, according to different deployment scenarios, to use different CP lengths. For example, in an indoor scenario, a CP of <NUM> is used; in a UMi (Urban Micro, Urban Micro) scenario, a CP length is <NUM>; and in a UMa (Urban Macro, Urban Macro) scenario, a CP length is <NUM>. The AP selects a corresponding CP length according to the scenario in which the AP is deployed, and indicates the corresponding CP length in the control domain. For example, if a system only supports indoor and UMi scenarios, <NUM>-bit information in the control domain is used for indication, indicating that <NUM> represents using <NUM>, and indicating that <NUM> represents using <NUM>; if the system further needs to support a UMa scenario, <NUM>-bit information in the control domain needs to be used for indication, indicating that <NUM> represents using <NUM>, indicating that <NUM> represents using <NUM>, and indicating that <NUM> represents using a CP of <NUM>.

The first radio resource indication includes: a size and a position of a radio resource block indicated by a first radio resource and a modulation and coding scheme and/or an MIMO (Multi-input Multi-output, multiple-input multiple-output) transmission manner used on the radio resource block.

Step <NUM>: The AP sends the preamble part and the control domain of the radio frame to a STA associated with the AP.

The preamble part and the control domain are different components of the radio frame, and the AP may first send the preamble part of the radio frame to the STA associated with the AP, and then send the control domain of the radio frame to the STA associated with the AP.

Optionally, when the AP sends the preamble part of the radio frame to the STA associated with the AP, the AP broadcasts the preamble part of the radio frame, so that not only the STA associated with the AP can receive the preamble part of the radio frame, but also a STA not associated with the AP can receive the preamble part of the radio frame. When the AP broadcasts the preamble part of the radio frame, the AP may increase transmit power of the preamble part of the radio frame, so that the STA not associated with the AP and another AP receive the preamble part of the radio frame, and within reserved duration, the STA not associated with the AP and the another AP no longer transmit wireless local area network data by using the radio channel. For example, in a case in which a peak-to-average rate is met, the transmit power of the preamble part of the radio frame may be increased by <NUM> dB.

By increasing the transmit power of the preamble part of the radio frame, a STA not associated with the AP and another AP may better receive the preamble part of the radio frame, and thereby the STA not associated with the AP and the another AP no longer transmit wireless local area network data by using the radio channel, avoiding interference to transmission of wireless local area network data between the AP and the STA associated with the AP when the STA not associated with the AP and the another AP transmit wireless local area network data, and achieving a relatively good effect.

Both the preamble part and the control domain are sent in an OFDM manner compatible with the existing IEEE802. <NUM> standard.

The existing IEEE802. <NUM> may be IEEE802.11a, IEEE802. <NUM>, IEEE802.11n or IEEE802.11ac.

When the preamble part and the control domain are sent, the preamble part and the control domain may be configured and sent according to an OFDM configuration parameter. For example, as shown in Table <NUM>, a first value column in Table <NUM> is an OFDM configuration parameter for configuring the preamble part and control domain, and a second value column is an OFDMA configuration parameter of an uplink data domain and a downlink data domain.

Further, duration of each downlink data domain or uplink data domain may be <NUM>, and when a second value in Table <NUM> is used to perform OFDMA modulation, each uplink or downlink data domain includes <NUM> OFDM symbols.

Optionally, when the second value in Table <NUM> is used to perform OFDMA modulation, each radio resource block may include <NUM> resource units occupied by <NUM> subcarriers and six OFDM symbols; in this case, one uplink or downlink data domain includes a total of <NUM> radio resource blocks. Alternatively, each radio resource block may also include <NUM> resource units occupied by <NUM> subcarriers and <NUM> OFDM symbols; in this case, one uplink or downlink data domain includes a total of <NUM> radio resource blocks.

Step <NUM>: The STA associated with the AP receives the preamble part and the control domain of the radio frame that are sent by the AP.

The AP first sends the preamble part of the radio frame, and then sends the control domain of the radio frame; therefore, the STA associated with the AP first receives the preamble part, sent by the AP, of the radio frame, and then receives the control domain, sent by the AP, of the radio frame.

Step <NUM>: The STA associated with the AP receives, in a downlink data domain included in the data domain of the radio frame, according to the preamble part and the control domain of the radio frame, wireless local area network data sent by the AP.

When the STA associated with the AP receives the preamble part of the radio frame, the STA synchronizes, according to the L-STF in the preamble part, with the AP associated with the STA, and performs channel estimation according to the L-LTF of the preamble part; and the STA acquires, by means of coherent reception, information that is related to duration of the radio frame and carried in the L-SIG of the preamble part of the radio frame.

The STA associated with the AP determines, according to configuration information, included in the control domain, of an uplink/downlink data domain in the radio frame, an OFDMA (Orthogonal Frequency Division Multiple Access, orthogonal frequency division multiple access) modulation parameter used by the data domain, and radio resource allocation indication information for the STA associated with the AP, a resource block corresponding to the STA in the downlink data domain in the data domain and a transmission parameter used for sending data of the resource block (for example, in an MCS or MIMO manner), and receives and demodulates, on the determined resource block, the wireless local area network data sent by the AP.

The data domain is sent in an OFDMA manner.

Step <NUM>: When the data domain of the radio frame includes an uplink data domain, the STA associated with the AP sends, in the uplink data domain included in the data domain, according to the control domain of the radio frame, wireless local area network data to the AP.

A specific operation of the sending, by the STA associated with the AP, in the uplink data domain included in the data domain, according to the control domain of the radio frame, wireless local area network data to the AP may be: performing, by the STA associated with AP, modulation and coding, according to the control domain of the radio frame, on wireless local area network data that needs to be sent, and sending, on a resource block corresponding to the STA, coded wireless local area network data to the AP.

A specific operation of the performing, by the STA associated with the AP, modulation and coding, according to the control domain of the radio frame, wireless local area network data that needs to be sent may be that: performing, by the STA associated with AP, according to an OFDM modulation parameter included in the control domain of the radio frame, configuration information, included in the control domain, of an uplink/downlink data domain in the radio frame, and radio resource allocation indication information for the STA associated with the AP, modulation and coding on the wireless local area network data that needs to be sent, determining a corresponding resource block of the STA in the uplink data domain, and sending, on the determined resource block, wireless local area network data on which modulation and coding are performed to the AP.

Further, before the reserved duration ends, if the AP wants to end the scheduling window, that is, the AP gives up the right to use of the radio channel, the AP may broadcast a giving up control frame, to state that the AP gives up the right to use of the radio channel. In this case, another AP or STA may acquire, in a contention manner, the right to use of the radio channel.

In this embodiment of the present invention, when a right to use of a radio channel is acquired, an AP may construct a radio frame, where the radio frame includes a preamble part, a control domain, and a data domain. The AP may increase transmit power of the preamble part, and broadcast the preamble part, so that not only a STA associated with the AP receives the preamble part, but also a STA not associated with the AP and another AP may receive the preamble part, and thereby the STA not associated with the AP and the another AP no longer transmit wireless local area network data by using the radio channel, avoiding interference to transmission of wireless local area network data between the AP and the STA associated with the AP when the STA not associated with the AP and the another AP transmit wireless local area network data, and achieving a relatively good effect. In addition, because the data domain of the radio frame may include multiple uplink data domains and multiple downlink data domains, and each uplink data domain or downlink data domain includes multiple radio resource blocks, each STA has a corresponding radio resource block. The STA associated with the AP may send, on a radio resource block corresponding to the STA in an uplink data domain, wireless local area network data to the AP. The AP may send, on a radio resource block corresponding to a STA in a downlink data domain, wireless local area network data to the STA associated with the AP. Because the AP may be associated with multiple STAs, the wireless local area network data can be transmitted between the AP and the STA in a one-to-many or many-to-one relationship, improving spectrum utilization and network use efficiency.

<FIG> is an apparatus for transmitting wireless local area network data according to an embodiment of the present invention. Referring to <FIG>, the apparatus includes: a first transmitter <NUM>, a first receiver <NUM>, a first memory <NUM>, and a first processor <NUM>, which are configured to execute the following method for transmitting wireless local area network data, where:.

Optionally, a length LENGTH data domain in the L-SIG domain carries a value related to the duration of the radio frame, and the duration, corresponding to the value, of the radio frame is greater than or equal to actual duration of the radio frame.

Further,
the first processor <NUM> is further configured to increase transmit power of the preamble part of the radio frame, so that a STA not associated with the AP and another AP receive the preamble part of the radio frame, and within reserved duration, the STA not associated with the AP and the another AP no longer transmit wireless local area network data by using the radio channel, where the reserved duration is duration within which the AP owns the right to use of the radio channel.

Optionally, the first radio resource indication includes: a size and a position of a radio resource block indicated by the first radio resource indication, and a modulation and coding scheme and/or a multiple-input multiple-output MIMO transmission manner used on the radio resource block.

Optionally,
the first receiver <NUM> is further configured to: when the data domain includes an uplink data domain, receive, in the uplink data domain included in the data domain, according to the control domain, wireless local area network data sent by the STA associated with the AP.

<FIG> is an apparatus for transmitting wireless local area network data according to an embodiment of the present invention. Referring to <FIG>, the apparatus includes: a second transmitter <NUM>, a second receiver <NUM>, a second memory <NUM>, and a second processor <NUM>, which are configured to execute the following method for transmitting wireless local area network data, where:.

The preamble part is a preamble part compatible with the existing Institute of Electrical and Electronics Engineers IEEE802. <NUM>, and the preamble part includes a legacy-short training field L-STF, a legacy-long training field L-LTF, and a legacy-signaling field L-SIG; and.

Optionally, the configuration information of the uplink/downlink data domain includes: a quantity of uplink data domains, a quantity of downlink data domains, and transformation information between the uplink data domain and the downlink data domain.

The OFDMA modulation parameter used by the data domain includes: channel bandwidth of a system, a used cyclic prefix CP length, a fast Fourier transformation FFT order, and a quantity of available subcarriers.

Optionally, the radio resource allocation indication information for the STA associated with the AP includes: a first radio resource indication, where the first radio resource indication is used to indicate a radio resource block corresponding to a second radio resource indication used by each scheduled STA to transmit data, or the first radio resource indication is used to indicate a radio resource block used by each scheduled STA to transmit data.

Further, the first radio resource indication includes: a size and a position of a radio resource block indicated by the first radio resource indication, and a modulation and coding scheme and/or a multiple-input multiple-output MIMO transmission manner used on the radio resource block.

Optionally,
the second transmitter <NUM> is configured to: when the data domain includes an uplink data domain, send, in the uplink data domain included in the data domain, according to the control domain, wireless local area network data to the AP associated with the STA.

A person of ordinary skill in the art may understand that all or some of the steps of the embodiments may be implemented by hardware or a program instructing related hardware. The program may be stored in a computer-readable storage medium. The storage medium may include: a read-only memory, a magnetic disk, or an optical disc.

It should further be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another, and do not necessarily require or imply that any actual relationship or sequence exists between these entities or operations. Moreover, the terms "include", "comprise", or their any other variant is intended to cover a non-exclusive inclusion, so that a process, a method, an article, or a device that includes a list of elements not only includes those elements but also includes other elements that are not expressly listed, or further includes elements inherent to such a process, method, article, or device. An element preceded by "includes a. " does not, without more constraints, preclude the presence of additional identical elements in the process, method, article, or device that includes the element.

Based on the description of the foregoing implementation manners, a person skilled in the art may clearly understand that the present invention may be implemented by software in addition to necessary universal hardware, where the universal hardware includes a universal integrated circuit, a universal CPU, a universal memory, a universal component, or the like, or may be implemented by dedicated hardware, including an application-specific integrated circuit, a dedicated CPU, a dedicated memory, a dedicated component, or the like. Based on such an understanding, the technical solutions of the present invention essentially or the part contributing to the prior art may be implemented in a form of a software product. The computer software product is stored in a readable storage medium, for example, various media that can store software program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk, or an optical disc, and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform the methods described in the embodiments of the present invention.

The following describes some specific implementation manners of the present invention by way of example only.

For details of a "reserved channel part" in a contention window shown above in <FIG>, refer to <FIG>. Specifically, before the constructing, by an AP, a radio frame after obtaining through contention a right to use of a channel, the method further includes: sending, by the AP, an RTS (English: Request To Send), and receiving one or more CTSs (English: Clear To Send) that one or more STAs associated with the AP reply with, where the one or more CTSs are used to indicate that a STA sending the CTS can receive or send data, (a channel condition allows receiving and sending of data). More specifically, when receiving the CTS, other communications nodes nearby do not use the channel to perform communication. That is, the STA protects, by sending the CTS, the channel from being used by the communications nodes nearby, to avoid causing interference.

More specifically, a receiver address of the RTS sent by the AP may be a group address, or may be an address of a specified STA, or may be addresses of all STAs associated with the AP. For example, the receiver address is represented by a default address, for example, by all zeros. After a STA that performs reception as instructed by the AP (that is, a STA indicated by the receiver address) receives the RTS, the STA replies with a CTS after a period of time, for example, after duration of an SIFS. For example, for a group of STAs in the STAs associated with the AP, particular STAs specified by the AP or all STAs reply with a CTS separately. Such replies may be sent by using a time division, code division, frequency division, or OFDMA technology, or may be superposed and sent on exactly a same resource.

As mentioned above, not only the AP may construct the radio frame according to a quantity of STAs associated with the AP, but also the AP may construct the radio frame according to a service between the AP and the STA associated with the AP. Certainly, the AP may also construct the radio frame in another manner. Specifically, the AP may determine, according to a received CTS, what kind of radio frame is to be constructed. For example, the AP determines, according to a quantity of received CTSs, a quantity of STAs that can be scheduled, and further determines scheduling duration or a quantity of radio frames to be scheduled, and a quantity of downlink subframes and a quantity of uplink subframes in a radio frame or a ratio of downlink subframes to uplink subframes in a radio frame. Further, if the STAs reply with the CTS in a group manner, the AP may further determine whether MU-MIMO transmission may be used in a radio frame, and determine how many resources may be allocated to perform MU-MIMO transmission, so as to determine an internal structure of the radio frame. For another example, the AP determines a transmission MCS in a scheduling period according to signal strength of the received CTS, so as to determine scheduling duration or a quantity of radio frames to be scheduled.

In frame structures shown in <FIG>, <FIG>, and <FIG>, there may be multiple specific frame structure replacing manners. For example, in the implementation manners of the present invention, a radio frame includes in sequence: a preamble part compatible with the existing IEEE802. <NUM> (hereinafter briefly referred to as Legacy preamble), a preamble part used in a next-generation standard (for example, HEW preamble), and the first downlink subframe, or may include another downlink subframe or an uplink subframe. The another downlink subframe or uplink subframe includes a training sequence field part of the next-generation standard, such as HEW STF and HEW LTF parts, and data, and does not include the preamble part compatible with the existing IEEE802.

In various frame structures provided by the implementation manners of the present invention, a radio frame includes: one or more downlink subframes and one or more uplink subframes. In this way, on the basis of the frame structure mentioned in the previous paragraph, a downlink subframe and an uplink subframe are alternated, the first subframe after the alternation includes a Legacy preamble and a preamble used in a next-generation standard (for example, HEW preamble). For example, after the TTG mentioned above, and before the first uplink data, the first subframe includes a Legacy preamble and a preamble used in a next-generation standard (for example, HEW preamble). Remaining non-first downlink subframes and non-first uplink subframes include a training sequence field part of the next-generation standard, for example, HEW STF and HEW LTF parts, and do not include the Legacy preamble and another part in the preamble of the next-generation standard.

In various frame structures provided by this implementation manner, a radio frame includes ACK information for a downlink subframe of the radio frame. For example, in a radio frame, ACK information for a downlink subframe is carried in a subsequent uplink subframe after the downlink subframe. These uplink subframes may be default. For example, the first uplink subframe or the first several uplink subframes after the downlink subframe carry the ACK information for the downlink subframe. In an example, the first UL subframe is used as an ACK reply, and the second and third UL subframes are used for transmission of uplink data payload. Certainly, these uplink subframes may also be indicated to an uplink STA by the AP in advance.

In a more specific example, after the uplink subframe that carries the ACK information for the downlink subframe, a radio frame includes a downlink subframe, where the downlink subframe is used to trigger transmission of a subsequent uplink subframe that carries data (payload), and the downlink subframe may carry information such as a resource allocation indicator, for example, resource block information of the subsequent uplink subframe. The downlink subframe may include only a legacy preamble and a preamble of a next-generation standard, for example, an HEW preamble, or may include a MAC PDU part besides the foregoing two parts.

It is also mentioned in the foregoing implementation manners that, the configuration information of the uplink/downlink data domain may include: a quantity of uplink data domains, a quantity of downlink data domains, and transformation information between the uplink data domain and the downlink data domain. It should be noted that, the configuration information of the uplink/downlink data domain may have multiple specific forms, which are not limited in the implementation manners of the present invention.

For example, referring to a schematic diagram of a data structure in <FIG>, in an implementation manner, Length in an L-SIG of a PPDU, that is, L-Length, is used to indicate a sum of lengths of an uplink data domain and a downlink data domain (downlink subframe and uplink subframe), and an HE-SIG includes information indicating a length of a downlink subframe (which, for example, may be named HE-Length). With this structure, downlink transmission and uplink transmission are fully protected.

For a WLAN system using the foregoing data structure, a receive end performs the following processing after receiving a PPDU:.

In a more specific example, for a receive end (HE receive end) using the foregoing data structure, if only downlink data needs to be received, signal receiving or CCA detection may be stopped within a time of the length of the uplink subframe obtained in step <NUM>. In this way, obviously, power can be reduced to some extent. If the receive end needs to send uplink data, the length of the uplink subframe obtained in step <NUM> is a limit or threshold for the receive end to send uplink data, that is, a length of data sent by the receive end needs to be less than the calculated length of the uplink subframe (UL MU PPDU).

After receiving the PPDU, another receive end (non-HE receive end) reads the L-Length carried in the L-SIG of the PPDU, and uses the L-Length as a length of the current frame (PPDU). Within a time indicated by the length, the non-HE receive end does not actively send data, to avoid causing interference to current transmission, or may no longer receive a signal or may stop CCA detection. In this way, obviously, power can also be reduced to some extent.

Further, length units of the L-length, the HE-Length, and the SIFS are unified or consistent, and are, for example, time, a quantity of bits, or a quantity of OFDM/OFDMA symbols.

For example, one method is to use time, for example, microsecond (µs), as the unit. Specifically, the L-length indicates a sum of time lengths of a downlink PPDU, an uplink PPDU, and an inter-frame space; the HE-Length indicates a time length of a downlink PPDU. Another method is to use an existing unit of the L-Length, that is, byte, as the unit.

In a specific example, a specific calculation method includes:
<MAT>
<MAT>.

L-Length = ceiling[TL-Length/Tsymbol]*Nsymbol, where a unit of Nsymbol is byte, which refers to a quantity of bytes included in each symbol; and
<MAT>.

If a quantity of OFDM/OFDMA symbols is used as a unit of length (length),
<MAT> and
<MAT>.

In the foregoing formulas, TL-Length is a time length indicated by the L-Length, TDL_PPDU is a time length required for sending a DL PPDU, TUL_PPDU is a time length required for sending an UL PPDU, SIFS is a short inter-frame space (Short Inter-frame Space), THE-Length is a time length indicated by the HE-Length, THE-SIG is a time length required for sending an HE-SIG, Tsymbol is a time length required for sending an OFDM symbol, and Ceiling[x] is a round-up operation performed on x.

In addition, refer to <FIG>, which is a schematic structural diagram of an uplink subframe sent by a STA. An L-Length in an L-SIG of the uplink subframe (uplink PPDU) is used to indicate a length of a multi-user part (uplink MU PPDU, including an HE-SIG and an uplink MU Part) of the uplink subframe. In this way, uplink transmission can be better protected.

In a specific example, in the uplink PPDU, by using a length unit being µs as an example, TL-Length = TUL_PPDU - <NUM>, where <NUM> is a length of a legacy preamble (Legacy Preamble).

Further, the uplink subframe sent by the STA may further include uplink resource allocation information (Resource Allocation) sent by an AP, and specifically, the uplink resource allocation information may be included in the HE-SIG of the sent uplink subframe.

On the basis of the foregoing data structure, after receiving the uplink subframe, a non-destination HE STA may perform the following processing:.

Duration indicates a time length of a current TXOP; therefore, its length is not limited to the current frame.

For the uplink subframe, the uplink subframe can be better protected by using the L-Length and/or Duration in the HE-SIG.

Claim 1:
A computer-readable storage medium, wherein the computer-readable storage medium stores instructions, and when the instructions are run on a computer in an access point, the computer is enabled to perform a method for transmitting wireless local area network, WLAN data between an access point and at least one station, wherein a time domain of the WLAN includes a contention window and a scheduling window, wherein if the AP obtains a right to use a channel in the contention window the AP is configured to enter the scheduling window, wherein the scheduling window is a time length during which a communication between the AP and the at least one station is scheduled by the AP, and wherein the method comprises:
within the scheduling window, sending a downlink, DL, subframe, wherein the DL subframe is configured to trigger a transmission of a UL subframe, and the DL subframe includes an IEEE <NUM>.11ac preamble and a high efficiency WLAN/WiFi, HEW, preamble; and
within the scheduling window, after sending the DL subframe, receivingthe UL subframe, wherein the UL subframe includes an IEEE <NUM>.11ac preamble, a HEW preamble, and a UL multi-user, MU, part, wherein the UL MU part includes ACK information for the DL subframe and UL data payload.