Patent Description:
The present disclosure relates to a wireless device a wireless control method, and a program.

In recent years, standardization of a new wireless LAN has been under review by IEEE <NUM> working groups and the like. For example, a method in which a plurality of wireless devices simultaneously perform data transmission with one access point device using multi-user spatial multiplex communication is under review. Patent Literature <NUM> discloses a communication control method in a wireless device that performs both multi-user spatial multiplex communication and single user communication.

Further prior art can be found in <CIT> disclosing station contention behavior in uplink multiple user protocols. IEEE contribution "<NPL> also deals with related topics.

However, in the wireless LAN system, implementation of the single user communication is delayed due to influence of implementation of the multi-user spatial multiplex communication. For example, when an operation mode is switched from the multi-user spatial multiplex communication to the single user communication, an initial value of a waiting time for the single user communication is reset. For this reason, even when data with high priority is transmitted, a wireless device is on standby until the reset waiting time elapses and performs data transmission using the single user communication after the waiting time elapses.

In this regard, the present disclosure was made in light of the foregoing, and provides a wireless device a wireless control method, and a program, which are novel and improved and capable of preventing the implementation of the single user communication from being delayed due to the influence of the implementation of the multi-user spatial multiplex communication in the wireless device that performs both the multi-user spatial multiplex communication and the single user communication.

According to the present disclosure, there are provided a wireless device, a wireless control method, and a program as defined in the claims.

As described above, according to an embodiment of the present disclosure, it is possible to prevent the implementation of the single user communication from being delayed due to the influence of the implementation of the multi-user spatial multiplex communication in the wireless device that performs both the multi-user spatial multiplex communication and the single user communication.

In this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation of these structural elements is omitted.

The description will proceed in the following order.

An embodiment of the present disclosure relates to a wireless LAN system. First, an overview of a wireless LAN system according to an embodiment of the present disclosure will be described with reference to <FIG>.

<FIG> is a diagram illustrating a configuration of the wireless LAN system according to an embodiment of the present disclosure. As illustrated in <FIG>, the wireless LAN system according to an embodiment of the present disclosure includes an access point device (hereinafter referred to as an "access point (AP)" for convenience) <NUM> and a station device (hereinafter referred to as a "station (STA)" for convenience) <NUM>. A basic service set (hereinafter referred to as a "BSS" for convenience) <NUM> is configured with one AP <NUM> and one or more STAs <NUM>.

The wireless LAN system according to an embodiment of the present disclosure can be installed in any place. For example, the wireless LAN system according to the present embodiment may be installed in an office building, a residential area, a commercial facility, a public facility, or the like. The BSS <NUM> may be arranged so that an area of the BSS <NUM> overlaps areas of other BSSs <NUM>.

The AP <NUM> according to the present embodiment functions as a communication device, is connected to an external network, and provides the STA <NUM> with communication with an external network. For example, the AP <NUM> is connected to the Internet and provides communication between the STA <NUM> and a device on the Internet or a device connected via the Internet.

Further, the AP <NUM> receives data using uplink multicast-user spatial multiplex communication (hereinafter referred to as "uplink multi-user (UL MU)" for convenience) or uplink single user communication (hereinafter referred to as "uplink single-user (UL SU)" for convenience).

To describe data reception using the UL MU in more detail, the AP <NUM> decides the STA <NUM> that executes the UL MU. Thereafter, the AP <NUM> generates a trigger frame (hereinafter referred to as "trigger" for convenience) including information related to the STA <NUM> which is permitted to perform the UL MU, information related to a period of time in which data transmission using the UL MU is performed, and the like (hereinafter referred to as "UL MU permission information" for convenience). Then, the AP <NUM> sets the waiting time before trigger transmission, and transmits the trigger to the STA <NUM> after the waiting time elapses, so that the STA <NUM> is allowed to perform the UL MU. The data reception by the AP <NUM> using the UL MU or the UL SU will be described later in detail.

The STA <NUM> according to the present embodiment is a wireless device that functions as a wireless device and communicates with the AP <NUM>. The STA <NUM> may be any wireless device. For example, the STA <NUM> may be a smartphone including a display having a display function, a memory having a storage function, a keyboard and a mouse having an input function, a speaker having an audio output function, and a function of executing an advanced calculation process.

The STA <NUM> according to the present embodiment performs data transmission to the AP <NUM> using the UL MU or the UL SU. To describe the data transmission using the UL MU specifically, the STA <NUM> receives the trigger from the AP <NUM>, and when its own STA <NUM> is included in the UL MU permission information included in the trigger, the STA <NUM> performs the data transmission to the AP <NUM> using the UL MU. In other words, the data transmission is performed to the AP <NUM> together with the STA <NUM> that is permitted to perform the UL MU other than its own STA. The data transmission by the STA <NUM> using the UL MU will be described later in detail.

Further, to describe the data transmission using the UL SU specifically, the STA <NUM> sets the waiting time before the UL SU on the basis of a priority of the transmission data, and after the waiting time has elapsed, the STA <NUM> performs the data transmission to the AP <NUM> using the UL SU. In other words, the STA <NUM> can perform the data transmission to the AP <NUM> using the UL SU without receiving the trigger of the UL MU. The data transmission by the STA <NUM> using the UL SU will be described later in detail.

In recent years, standardization of a new wireless LAN has been under review by IEEE <NUM> working groups and the like. Such review has included review for improving a communication control method using the UL MU and the UL SU in a method of a related art while securing compatibility with the method of the related art.

As the communication control method using the UL MU and the UL SU, for example, there is a disclosure of the related art <NUM>. In this regard, content of the disclosure of the related art <NUM> will be described with reference to <FIG> is a diagram illustrating communication between an AP and an STA in the disclosure of the related art <NUM>. As illustrated in <FIG>, for example, there is a wireless LAN system including one AP and three STAs (STAs <NUM> to <NUM>).

First, in step S1000, the AP transmits a polling frame including information related to permission of the UL MU to each of the STAs. Here, the information related to the permission of the UL MU included in the polling refers to information related to an STA which executes the UL MU, a period of time for performing the UL MU (transmission opportunity (TXOP)), and the like. Each STA receives the polling frame, and checks the information related to the permission of the UL MU included in the polling frame. In steps S1004 to S1012, each STA transmits the data transmission to the AP using the UL MU during the period of time of the TXOP designated by the polling when its own STA is included as the STA that is permitted to perform the UL MU.

Thus, in the disclosure of the related art <NUM>, the data transmission by each STA is controlled by the polling transmitted from the AP. Therefore, the STA is unable to perform random access control in accordance with the priority of the transmission data. In the disclosure of related art <NUM>, in order to enable the transmission control according to the priority of the transmission data held in the STA, it is necessary for the AP to detect the priority of the transmission data held in the STA in advance, but it is not easy to realize this.

Further, immediately after the TXOP ends, when the AP transmits the polling and sets a new TXOP, the STA has no opportunity to autonomously perform the data transmission. Therefore, the feasibility of the data transmission according to the priority of transmission data by STA is further lowered.

Next, the background of the present disclosure from another point of view will be described. In <FIG>, it is assumed that the data transmitted by the STA <NUM> in step S1012 is not received by the AP for some reason. In step S1016, the AP that has received the data transmitted by STA1 and STA2 generates a Block-ACK frame (hereinafter referred to as a "BA" for convenience) and transmits the BA to the respective STAs. The BA is a response frame including information related to a reception state of the frame transmitted by each STA. Since information indicating that the data transmitted by the STA <NUM> and the STA <NUM> has been received by the AP is included in the BA, the STA <NUM> and the STA <NUM> that have received the BA can detect that the transmission data has been properly received by the AP.

On the other hand, since the BA does not include information indicating that the data transmitted by the STA <NUM> has been received by the AP, the STA <NUM> that has received the BA determines that the transmission data has not been correctly received by the AP, and attempts to retransmit the transmission data. At that time, in step S1020, the STA <NUM> resets a contention window (hereinafter referred to as a "CW" for convenience) and resets a backoff counter on the basis of the CW. Therefore, the STA <NUM> retransmits the data using the UL SU after an arbitration inter frame space (hereinafter referred to as an "AIFS" for convenience) elapses, and the reset backoff counter becomes <NUM>.

As described above, in the disclosure of related art <NUM>, since the CW and the backoff counter are reset for the data transmission by the UL SU, the data transmission by the UL SU may be delayed from a desired timing. In this case, when the priority of the transmission data is high such as when the transmission data is audio data, the transmission data is significantly influenced.

Next, the background of the present disclosure will be described with reference to <FIG> is a diagram illustrating communication between the AP and the STA.

As illustrated in <FIG>, after the backoff counter set on the basis of the CW corresponding to three slots becomes <NUM> in step S <NUM>, in step S1104, the AP transmits the trigger including the information related to the permission of the UL MU to each STA. Each STA receives the trigger and checks the information related to the permission of the UL MU included in the trigger. In steps S1108 to S1116, each STA performs the data transmission to the AP using the UL MU during a period of time designated by the trigger when its own STA is included as the STA that is permitted to perform the UL MU.

In <FIG>, it is assumed that the data transmitted by the STA <NUM> is not received by the AP for some reason. In step S1120, the AP that has received the data transmitted by the STA <NUM> and the STA <NUM> generates a Multi-Block-ACK frame (hereinafter referred to as an "M-BA" for convenience) and transmits the M-BA to each STA. The M-BA is a response frame including information related to a reception state of the frame transmitted from each STA using the UL MU.

Since the information indicating that the data transmitted by the STA <NUM> and the STA <NUM> has been received by the AP is included in the M-BA, the STA <NUM> and the STA <NUM> that have received the M-BA can detect that the transmission data has been properly received by the AP. On the other hand, since the M-BA does not include information indicating that the data transmitted by the STA <NUM> has been received by the AP, the STA <NUM> that has received the M-BA can detect that the transmission data has not been correctly received by the AP.

After the backoff counter set on the basis of the CW corresponding to three slots becomes <NUM> in step S1124, in step S1128, the AP retransmits the trigger to each STA. In steps S1132 to S1140, each STA performs the data transmission to the AP using the UL MU during the period of time designated by the trigger when its own STA is included in the STA that is permitted to perform the UL MU. At this time, since the STA <NUM> detects that the previous transmission data has not been correctly received by the AP, the STA <NUM> retransmits the previous transmission data.

In step S1144, the AP that has received the data transmitted by the STAs <NUM> to <NUM> generates the M-BA and transmits the M-BA to each STA. In <FIG>, it is assumed that the M-BA has not been received by the STA <NUM> for some reason. When the M-BA is unable to be received during a standby time for reception of the M-BA, the STA <NUM> determines that the transmission data has not been correctly received by the AP and attempts to retransmit the transmission data.

In step S1148, the STA <NUM> resets the CW (the CW is reset to a CW corresponding to six slots in <FIG>), and resets the backoff counter on the basis of the CW. Then, after the IFS elapses and the re-set backoff counter becomes <NUM>, in step S1152 the STA <NUM> retransmits the data using the UL SU. When the data transmitted using the UL SU is correctly received by the AP, the AP generates a Single-Block-ACK frame (hereinafter referred to as an "S-BA" for convenience) and transmits the S-BA to the STA <NUM>. The S-BA is a response frame including information related to a reception state of the frame transmitted from each STA using the UL SU. Since information indicating that the data transmitted by the STA <NUM> has been received by the AP is included in the S-BA, the STA <NUM> that has received the S-BA can detect that the transmission data has been correctly received by the AP.

As described above, even in the method of <FIG>, the CW is reset for the data transmission using the UL SU, and the backoff counter is also reset on the basis of the CW, similarly to the disclosure of related art <NUM>, and thus the data transmission by the UL SU may be delayed from a desired timing.

In this regard, the disclosers of the present case have devised the present disclosure in view of the above circumstances. An STA <NUM> of the wireless LAN system according to an embodiment of the present disclosure can perform the data transmission according to the priority of the transmission data using the UL SU regardless of the UL MU. In addition, the STA <NUM> does not reset the backoff counter when the data transmission using the UL SU is performed after the UL MU, and thus it is possible to prevent the data transmission from being delayed due to the resetting of the backoff counter. In other words, the STA <NUM> can prevent the implementation of the UL SU from being delayed due to the implementation of the UL MU. The STA <NUM> and the AP <NUM> according to the present embodiment have compatibility with the STA and the AP employing the method of the related art. For example, the STA <NUM> and the AP <NUM> according to the present embodiment can correctly communicate with both the STA and the AP that perform random access control based on CSMA/CA using the method of the related art.

The background of the present disclosure has been described above. Next, a function overview of the wireless LAN system according to an embodiment of the present disclosure will be described with reference to <FIG> and <FIG>. <FIG> and <FIG> are diagrams illustrating communication between the AP <NUM> and the STA <NUM> according to the present embodiment.

Steps S1200 to S1244 in <FIG> are the same as the steps S1100 to S1144 in <FIG>, and thus description thereof is omitted. In steps S1248 and S1252, an STA 100c according to the present embodiment decreases a UL SU backoff counter during a period in which the AP <NUM> decreases a UL MU backoff counter in steps S1200 and S1224.

Here, the backoff counter is set in accordance with the priority which is decided in accordance with an access category of transmission data (hereinafter referred to as an "access category (AC)" for convenience). Specifically, as the priority decided in accordance with the AC of the transmission data increases, the backoff counter decreases. In other words, as the priority of transmission data increases, the waiting time of the data transmission using the UL SU decreases. Further, when the trigger transmitted from the AP <NUM> is received, the STA 100c suspends the decreasing of the UL SU backoff counter.

When the M-BA is unable to be received in step S1244, the STA 100c determines that the transmission data has not been correctly received by the AP <NUM> and attempts to retransmit the transmission data. In this case, in step S1256, the STA 100c continues to decrease the backoff counter that has already been decreased without resetting the CW and the backoff counter. Then, after the UL SU backoff counter becomes <NUM>, in step S1260, the STA 100c retransmits the data using the UL SU. Although not illustrated, when the UL SU backoff counter becomes <NUM> before the trigger transmission by the AP <NUM>, the STA 100c performs the data transmission to the AP <NUM> using the UL SU before the trigger transmission by the AP <NUM>.

As described above, the STA <NUM> of the wireless LAN system according to the present embodiment can perform the data transmission according to the priority of the transmission data using the UL SU regardless of the UL MU. Further, since the STA <NUM> does not reset the backoff counter when the data transmission using the UL SU is performed after the UL MU, it is possible to prevent the data transmission from being delayed due to the resetting of the backoff counter. In other words, the STA <NUM> can prevent the implementation of the UL SU from being delayed due to the implementation of the UL MU. The STA <NUM> and the AP <NUM> according to the present embodiment have compatibility with the STA and the AP employing the method of the related art. For example, the STA <NUM> and the AP <NUM> according to the present embodiment can correctly communicate with both the STA and the AP that perform random access control based on CSMA/CA using the method of the related art.

Next, communication between the AP <NUM> and the STA <NUM> in a case different from that in <FIG> will be described with reference to <FIG> is a diagram illustrating an operation in which the STA 100c performs the UL SU when the STA 100c is not included as the STA <NUM> that is permitted to perform the UL MU.

As illustrated in <FIG>, in step S1300, the AP <NUM> decreases the backoff counter set based on the CW corresponding to three slots. Then, similarly to <FIG>, in step S1308, the STA 100c decreases the UL SU backoff counter during a period in which the UL MU backoff counter is decreased by the AP <NUM>.

After the UL MU backoff counter becomes <NUM>, in step S1304, the AP <NUM> transmits the trigger including the UL MU permission information to each STA <NUM>. Each STA <NUM> receives the trigger, and checks the UL MU permission information included in the trigger. In steps S1312 to S1316, an STA 100a and an STA 100b check that they, the STAs, themselves are included as the STA <NUM> that is permitted to perform the UL MU, and perform the data transmission to the AP <NUM> using the UL MU during a period of time designated by the trigger.

In step S1320, the STA 100c suspends the decreasing of the UL SU backoff counter at a timing at which the trigger is detected, checks that it, the STA, itself is not included as the STA <NUM> that is allowed to perform the UL MU, and sets a transmission prohibition period (hereinafter referred to as a "network allocation vector (NAV)" for convenience). The STA 100c is unable to transmit a signal during a period in which the NAV is set.

In step S1324, the AP <NUM> that has received the data transmitted by the STA 100a and the STA 100b generates the M-BA and transmits the M-BA to each STA <NUM>. Thereafter, in step S1328, the AP <NUM> starts to decrease the UL MU backoff counter. The STA 100c that has received the M-BA detects that the UL MU has been completed and cancels the NAV. Then, in step S1332, the STA 100c restarts decrease of the UL SU backoff counter which has been suspended.

Then, after the UL SU backoff counter becomes <NUM>, in step S1336, the STA 100c performs the data transmission to the AP <NUM> using the UL SU. Upon receiving the data transmitted by the STA 100c, the AP <NUM> suspends the decreasing of the UL MU backoff counter. Then, when the data transmitted using the UL SU is correctly received by the AP <NUM>, the AP <NUM> transmits the S-BA to the STA <NUM>. Thereafter, in step S1344, the AP <NUM> restarts the decreasing of the UL MU backoff counter that has been suspended. Steps S1344 to S1364 are the same as the steps S1304 to S1324, and thus description thereof is omitted.

As described above, the STA <NUM> according to the present embodiment can perform the data transmission according to the priority of the transmission data using the UL SU regardless of the UL MU. In other words, the STA <NUM> can prevent the implementation of the UL SU from being delayed due to the implementation of the UL MU. The STA <NUM> and the AP <NUM> according to the present embodiment have compatibility with the STA and the AP employing the method of the related art. For example, the STA <NUM> and the AP <NUM> according to the present embodiment can correctly communicate with both the STA and the AP that perform random access control based on CSMA/CA using the method of the related art.

The function overview of the wireless LAN system according to an embodiment of the present disclosure has been described above. Next, a configuration of the STA <NUM> according to the present embodiment will be described with reference to <FIG>.

<FIG> is a diagram illustrating a configuration of the STA <NUM> according to an embodiment of the present disclosure. As illustrated in <FIG>, the STA <NUM> includes a wireless communication unit <NUM>, a data processing unit <NUM>, and a control unit <NUM>.

As illustrated in <FIG>, the wireless communication unit <NUM> includes an antenna control unit <NUM>, a reception processing unit <NUM>, and a transmission processing unit <NUM>. The wireless communication unit <NUM> functions as a communication unit.

The antenna control unit <NUM> controls transmission and reception of a signal via at least one antenna. More specifically, the antenna control unit <NUM> provides a signal received via the antenna to the reception processing unit <NUM>, and transmits a signal generated by the transmission processing unit <NUM> via the antenna.

The reception processing unit <NUM> performs a reception process on frames on the basis of the signal provided from the antenna control unit <NUM>. For example, the reception processing unit <NUM> performs an analog process and down-conversion on the signal obtained from the antenna, and outputs a baseband reception signal. Then, the reception processing unit <NUM> calculates a correlation between one or two or more signal patterns and the reception signal while shifting the reception signal to be operated on a time axis, and detects a preamble on the basis of the appearance of a correlation peak. Accordingly, the reception processing unit <NUM> can detect the trigger, the M-BA, the S-BA, the data frame, and the like which are transmitted by the AP <NUM>. Further, the reception processing unit <NUM> acquires the frames by performing demodulation, decoding, and the like on the baseband reception signal, and provides the acquired frames to a received frame analyzing unit <NUM>. Further, the reception processing unit <NUM> provides information related to the success or failure of the frame acquisition to a transmission control unit <NUM>.

The transmission processing unit <NUM> performs a process of transmitting the frame provided from a transmission frame constructing unit <NUM>. More specifically, the transmission processing unit <NUM> generates a signal to be transmitted on the basis of the frame provided from the transmission frame constructing unit <NUM> and a parameter set according to an instruction given from the transmission control unit <NUM>. For example, the transmission processing unit <NUM> generates a baseband transmission signal by performing encoding, interleaving, and modulation on the frame provided from the transmission frame constructing unit <NUM> in accordance with a coding and modulation scheme or the like instructed by the transmission control unit <NUM>. Further, the transmission processing unit <NUM> upconverts the baseband transmission signal obtained through the process of a preceding stage.

As illustrated in <FIG>, the data processing unit <NUM> includes the received frame analyzing unit <NUM>, a receiving buffer <NUM>, an interface unit <NUM>, a transmitting buffer <NUM>, and a transmission frame constructing unit <NUM>.

The received frame analyzing unit <NUM> analyzes a received frame. More specifically, the received frame analyzing unit <NUM> acquires a type (the trigger, the M-BA, the S-BA, the data frame, or the like), a destination, and a transmission source of a frame received by the wireless communication unit <NUM> and data or control information included in the frame. For example, the received frame analyzing unit <NUM> acquires data or the like included in the received frame by performing analysis of a header, detection and correction of a code error, a reordering process, and the like on the received frame.

Further, when the trigger transmitted by the AP <NUM> is received, the received frame analyzing unit <NUM> acquires the UL MU permission information included in the trigger. Then, when its own STA is included as the STA <NUM> that is permitted to perform the UL MU, the received frame analyzing unit <NUM> provides information indicating that its own STA is included as the STA <NUM> that is permitted to perform the UL MU and information used for implementation of the UL MU (a period of time in which the data transmission using the UL MU is performed, information related to a frame length in the UL MU, or the like) to the transmission control unit <NUM>. Further, when the M-BA or the S-BA transmitted by the AP <NUM> is received, the received frame analyzing unit <NUM> acquires transmission data reception result information included in the M-BA or the S-BA, and transmits the information to the transmission control unit <NUM>.

The receiving buffer <NUM> stores received data. More specifically, the receiving buffer <NUM> stores data included in the received frame.

The interface unit <NUM> is an interface that is connected with other components installed in the STA <NUM>. More specifically, the interface unit <NUM> performs reception of data that is desired to be transmitted from the other components, for example, an application, a user interface, provision of received data to an application or a user interface, or the like.

The transmitting buffer <NUM> stores transmission data. More specifically, the transmitting buffer <NUM> stores the transmission data obtained through the interface unit <NUM> so that the transmission data is distinguished for each AC.

The transmission frame constructing unit <NUM> generates a frame to be transmitted. More specifically, the transmission frame constructing unit <NUM> generates a frame on the basis of the transmission data stored in the transmitting buffer <NUM> or the control information set by the control unit <NUM>. For example, the transmission frame constructing unit <NUM> generates a frame (packet) from the transmission data acquired from the transmitting buffer <NUM> and performs a process such as addition of a media access control (MAC) header for MAC and addition of an error detection code to the generated frame.

As illustrated in <FIG>, the control unit <NUM> includes a CW processing unit <NUM> and the transmission control unit <NUM>.

The CW processing unit <NUM> functions as a setting unit, decides the CW in accordance with the priority of the AC of the transmission data, and sets the UL SU backoff counter on the basis of the CW. More specifically, the CW processing unit <NUM> sets the CW such that the CW decreases as the priority of the AC increases, and acquires a backoff counter which is a random number between <NUM> and the CW using the CW.

Then, the CW processing unit <NUM> decreases the UL SU backoff counter. More specifically, as long as a transmission path is detected to be in an idle state, the CW processing unit <NUM> decreases the UL SU backoff counter by one during the period in which the AP <NUM> decreases the UL MU backoff counter.

Here, the STA <NUM> and the AP <NUM> are in synchronization with each other on the basis of a reception timing of various kinds of frames (the trigger, the M-BA, the S-BA, and the like), and the CW processing unit <NUM> decreases the UL SU backoff counter in synchronization with the decreasing of the UL MU backoff counter by the AP <NUM>. For example, the CW processing unit <NUM> decreases the UL SU backoff counter in step S1248 of <FIG>, and suspends the decreasing of the backoff counter when the trigger is received from the AP <NUM> in step S1204. Then, the CW processing unit <NUM> restarts the decreasing of the backoff counter at a timing at which the response frame (the M-BA or the like) is received from the AP <NUM> or at a timing at which a reception standby time for the response frame elapses.

Then, when the backoff counter corresponding to a certain AC becomes <NUM>, the CW processing unit <NUM> sets a transmission enable flag for the AC. In other words, the transmission enable flag is set for each AC, and an AC in which the data transmission using the UL SU can be performed is determined on the basis of the transmission enable flag. Here, the period in which the backoff counter is decreased for the data transmission using the UL SU is referred to as a "first waiting time.

As described above, as the priority of the AC increases, the CW decreases, and thus the backoff counter which is a random number between <NUM> and the CW decreases. In other words, as the priority of the transmission data increases, the waiting time of the data transmission using the UL SU decreases.

Here, the type of the AC and the priority of the AC will be described with reference to <FIG> is a diagram illustrating the type of the AC and the priority of the AC. As illustrated in <FIG>, in IEEE802. <NUM>, the AC is classified into four types: AC_VO (Voice); AC_VI (Video); AC_BE (Best Effort); and AC_BK (Background). A priority is assigned to each of the four types of ACs. Specifically, as illustrated in <FIG>, the priority of AC_VO is set to be highest, and the priority of AC_BK is set to be lowest. Then, priority control is implemented by deciding the data transmission interval (the AIFS or the like) or a setting range of the CW in accordance with the priority for each AC.

The transmission control unit <NUM> controls the data transmission. For example, the transmission control unit <NUM> controls transmission of signals using the UL SU or the UL MU. To describe the data transmission using the UL SU more specifically, when the transmission data is stored in the transmitting buffer <NUM>, the transmission control unit <NUM> instructs the transmission frame constructing unit <NUM> to generate a frame in which the transmission data is stored. Then, the transmission control unit <NUM> instructs the CW processing unit <NUM> to set the backoff counter and decrease the backoff counter. Thereafter, when information indicating that the backoff counter becomes <NUM> (that is, the transmission enable flag of a certain AC is set) is provided from the CW processing unit <NUM>, the transmission control unit <NUM> instructs the transmission processing unit <NUM> to perform the data transmission using the UL SU.

Further, to describe the data transmission using the UL MU more specifically, when the transmission data is stored in the transmitting buffer <NUM>, the transmission control unit <NUM> instructs the transmission frame constructing unit <NUM> to generate a frame in which the transmission data is stored. When information indicating that its own STA is included as the STA <NUM> that is permitted to perform the UL MU is provided from the received frame analyzing unit <NUM>, the transmission control unit <NUM> instructs the transmission processing unit <NUM> to perform the data transmission using the UL MU.

The configuration of the STA <NUM> has been described above. Next, a configuration of the AP <NUM> will be described with reference to <FIG>.

<FIG> is a diagram illustrating the configuration of the AP <NUM> according to an embodiment of the present disclosure. As illustrated in <FIG>, the AP <NUM> may have the same configuration as the STA <NUM> illustrated in <FIG>. It will be appreciated that the AP <NUM> may be configured to include a component which is not installed in the STA <NUM>. In the following description, description of components having the same functions as those of the STA <NUM> will be omitted.

As illustrated in <FIG>, a wireless communication unit <NUM> includes an antenna control unit <NUM>, a reception processing unit <NUM>, and a transmission processing unit <NUM>. The wireless communication unit <NUM> functions as a communication unit. Since the reception processing unit <NUM> and the transmission processing unit <NUM> have the same functions as those in the wireless communication unit <NUM> of the STA <NUM>, description thereof is omitted.

The antenna control unit <NUM> can perform space division multiplex communication by controlling transmission and reception of signals via a plurality of antennas. The number of antennas is arbitrary. Since the other functions of the antenna control unit <NUM> are the same as those of the antenna control unit <NUM> of the STA <NUM>, description thereof is omitted.

As illustrated in <FIG>, a data processing unit <NUM> includes a received frame analyzing unit <NUM>, a receiving buffer <NUM>, an interface unit <NUM>, a transmitting buffer <NUM>, and a transmission frame constructing unit <NUM>. Since the received frame analyzing unit <NUM>, the receiving buffer <NUM>, the interface unit <NUM>, and the transmitting buffer <NUM> have the same functions as those in the data processing unit <NUM> of the STA <NUM>, description thereof is omitted.

The transmission frame constructing unit <NUM> is controlled by the transmission control unit <NUM> and generates the trigger, the M-BA or the S-BA. For example, the transmission frame constructing unit <NUM> generates the trigger including the UL MU permission information provided from the transmission control unit <NUM>. Further, the transmission frame constructing unit <NUM> generates the M-BA or the S-BA on the basis of the information related to the success or failure of the frame acquisition provided from the transmission control unit <NUM>. It will be appreciated that, similarly to the transmission frame constructing unit <NUM> of the STA <NUM>, the transmission frame constructing unit <NUM> may generate the frame including the transmission data stored in the transmitting buffer <NUM>.

As illustrated in <FIG>, a control unit <NUM> includes a CW processing unit <NUM> and the transmission control unit <NUM>.

The CW processing unit <NUM> functions as a setting unit, decides the CW of the trigger for the UL MU, and sets the UL MU backoff counter on the basis of the CW. More specifically, the CW processing unit <NUM> decides the CW for transmitting the trigger including the UL MU permission information. Here, the CW processing unit <NUM> sets a CW smaller than the CW for the data transmission using the UL SU by the STA <NUM> as the CW of the trigger. Accordingly, since the UL MU backoff counter can be set to be smaller than the UL SU backoff counter, the trigger transmission for the UL MU can be performed preferentially over the data transmission using the UL SU by the STA <NUM>. It will be appreciated that the CW processing unit <NUM> may set the CW which is equal to or more than the CW for the data transmission using the UL SU as the CW of the trigger.

Then, the CW processing unit <NUM> decreases the UL MU backoff counter. More specifically, as long as the transmission path is detected to be in the idle state, the CW processing unit <NUM> decreases the backoff counter by one during the period in which the STA <NUM> decreases the UL SU backoff counter. Here, for example, the CW processing unit <NUM> decreases the UL MU backoff counter in step S1328 in <FIG>, and when the data transmitted from the STA 100c using the UL SU is received, the CW processing unit <NUM> suspends the decreasing of the backoff counter in step S1336. Then, after the S-BA is transmitted to the STA 100c in step S1340, the CW processing unit <NUM> restarts the decreasing of the backoff counter in step S1344.

Then, when the backoff counter corresponding to a certain AC becomes <NUM>, the trigger is able to be transmitted. Here, a period in which the backoff counter is decreased for the trigger transmission for the UL MU is referred to as a "second waiting time. " Since the other functions of the CW processing unit <NUM> are the same as those of the CW processing unit <NUM> of the STA <NUM>, description thereof is omitted.

The transmission control unit <NUM> controls the data transmission. For example, the transmission control unit <NUM> controls transmission of the trigger, the M-BA, the S-BA or the data frame. To describe the transmission control of the trigger more specifically, the transmission control unit <NUM> provides the UL MU permission information to the transmission frame constructing unit <NUM> and instructs the transmission frame constructing unit <NUM> to generate the trigger. Then, the transmission control unit <NUM> instructs the CW processing unit <NUM> to set the backoff counter and decrease the backoff counter. Thereafter, when the information indicating that the backoff counter has become <NUM> is provided from the CW processing unit <NUM>, the transmission control unit <NUM> instructs the transmission processing unit <NUM> to transmit the trigger.

Further, if the transmission control of the M-BA or the S-BA is described more specifically, when data is received in accordance with the UL MU or the UL SU, the transmission control unit <NUM> provides the information related to the success or failure of the frame acquisition to the transmission frame constructing unit <NUM> and instructs the transmission frame constructing unit <NUM> to generate the M-BA or the S-BA. Then, the transmission control unit <NUM> instructs the transmission processing unit <NUM> to transmit the M-BA or the S-BA.

The configuration of the AP <NUM> according to the present embodiment has been described above. Next, the data transmission operation by the STA <NUM> will be described with reference to <FIG> and <FIG>. <FIG> and <FIG> are flowcharts illustrating the data transmission operation by the STA <NUM>.

First, when the transmission data is provided from the application or the user interface via the interface unit <NUM> in step S1400 (Yes in step S1400), in step S1404, the transmission data is stored in the transmitting buffer <NUM>. In step S1408, the CW processing unit <NUM> acquires AC information of the transmission data, and in step S1412, the CW processing unit <NUM> decides the CW in accordance with the acquired priority of the AC and sets the backoff counter on the basis of the CW. When the transmission data is not provided in step S1400 (No in step S1400), the process proceeds to step S1416.

Thereafter, when the wireless transmission path is in the idle state (Yes in step S1416), after a predetermined slot time period elapses (Yes in step S1420), in step S1424, the CW processing unit <NUM> decreases the backoff counter. When the wireless transmission path is not in the idle state in step S1416 (No in step S1416), the process proceeds to step S1436. When the predetermined slot time period does not elapse in step S1420 (No in step S1420), the process proceeds to step S1416.

When the backoff counter corresponding to a certain AC becomes <NUM> (Yes in step S1428), in step S1432, the CW processing unit <NUM> sets the transmission enable flag for the AC. When there is no AC in which the backoff counter is <NUM> in step S <NUM> (No in step S1428), the process proceeds to step S1436.

Here, even when the backoff counter of a certain AC becomes <NUM>, and the transmission enable flag is set for the AC, in step S1436, it is checked whether or not the trigger of the UL MU is received. Thus, when the trigger of the UL MU is received at a timing at which the backoff counter of a certain AC becomes <NUM>, the data transmission by the UL MU can be performed preferentially over the data transmission by the UL SU.

When the wireless communication unit <NUM> receives the trigger from the AP <NUM> (Yes in step S1436), the received frame analyzing unit <NUM> acquires the UL MU permission information included in the trigger. Then, when its own STA is included as the STA <NUM> that is permitted to perform the UL MU (Yes in step S1444), the received frame analyzing unit <NUM> provides information indicating that its own STA is included as the STA <NUM> that is permitted to perform the UL MU and information used for implementation of the UL MU (a period of time in which the data transmission using the UL MU is performed, information related to a frame length in the UL MU, or the like) to the transmission control unit <NUM>. In step S1448, the transmission control unit <NUM> checks the presence or absence of the transmission data of each AC in the transmitting buffer <NUM>.

When there is transmission data (Yes in step S1448), in step S1452, the transmission control unit <NUM> instructs the transmission frame constructing unit <NUM> to generate a transmission frame. Then, after the transmission frame is generated, the transmission control unit <NUM> instructs the transmission processing unit <NUM> to perform the data transmission using the UL MU. At this time, the transmission control unit <NUM> provides the information used for the implementation of the UL MU to the transmission frame constructing unit <NUM> and the transmission processing unit <NUM>. When its own STA is not included as the STA <NUM> that is permitted to perform the UL MU in step S1444 (No in step S1444), the NAV is set, and the process proceeds to step S1428.

After the data transmission using the UL MU, when the wireless communication unit <NUM> receives the M-BA from the AP <NUM> (Yes in step S1456), the received frame analyzing unit <NUM> acquires transmission data reception result information included in the M-BA. When information indicating that the transmission data has been correctly received by the AP <NUM> is included in the reception result information (step Yes in S1460), in step S1464, the transmission control unit <NUM> deletes the transmission data stored in the transmitting buffer <NUM>.

Then, when it is completely checked whether all data stored in the transmitting buffer <NUM> has been received (Yes in step S1468), the series of data transmission processes by the STA <NUM> is completed. When the wireless communication unit <NUM> does not receive the M-BA from the AP <NUM> in step S1456 (No in step S1456), when information indicating that the transmission data has been received correctly in the AP <NUM> is not included in the reception result information in step S1460 (No in step S1460), or when it is not completely checked whether all data stored in the transmitting buffer <NUM> has been received in step S1468 (No in step S1468), the process proceeds to step S1400.

When the wireless communication unit <NUM> does not receive the trigger from the AP <NUM> in step S1436 (No in step S1436), the transmission control unit <NUM> checks whether or not there is an AC in which the transmission enable flag is set. When there is an AC in which the transmission enable flag is set (step Yes in S1476), in step S1480, the transmission control unit <NUM> instructs the transmission frame constructing unit <NUM> to generate the transmission frame using the transmission data of the AC. After the transmission frame is generated, the transmission control unit <NUM> instructs the transmission processing unit <NUM> to transmit the data transmission using the UL SU.

Thereafter, when the wireless communication unit <NUM> receives the S-BA from the AP <NUM> (Yes in step S1484), the received frame analyzing unit <NUM> acquires transmission data reception result information included in the S-BA. When information indicating that the transmission data has been correctly received by the AP <NUM> is included in the reception result information (Yes in step S1488), the process proceeds to step S1464. When there is no AC in which the transmission enable flag is set in step S1476 (step No in S1476), when the wireless communication unit <NUM> does not receive the S-BA from the AP <NUM> in step S1484 (No in step S1484), or when the information indicating that the transmission data has been correctly received by the AP <NUM> is not included in the reception result information in step S1488 (No in step S1488), the process proceeds to step S1400.

The data transmission operation by the STA <NUM> has been described above, and now application examples of the present disclosure will be described below.

The technology of the present disclosure can be applied to various products. For example, the STA <NUM> may be implemented as a mobile terminal such as a smartphone, a tablet personal computer (PC), a laptop PC, a portable game terminal, or a digital camera, a fixed terminal such as a television receiver, a printer, a digital scanner, or a network storage, or an in-vehicle terminal such as a car navigation apparatus. Further, the STA <NUM> may be implemented as a terminal that performs machine to machine (M2M) communication (also referred to as a "machine type communication (MTC) terminal") such as a smart meter, a vending machine, a remote monitoring device, or a point of sale (POS) terminal. Further, the STA <NUM> may be a wireless communication module mounted on any such terminal (for example, an integrated circuit module configured with one die).

On the other hand, for example, the AP <NUM> may be implemented as a wireless LAN access point having a router function or having no router function (also referred to as a "wireless base station"). Further, the AP <NUM> may be implemented as a mobile wireless LAN router. Further, the AP <NUM> may be a wireless communication module mounted on any such device (for example, an integrated circuit module configured with one die).

<FIG> is a block diagram showing an example of a schematic configuration of a smartphone <NUM> to which the technology of the present disclosure can be applied. The smartphone <NUM> includes a processor <NUM>, a memory <NUM>, a storage <NUM>, an externally connected interface <NUM>, a camera <NUM>, a sensor <NUM>, a microphone <NUM>, a input device <NUM>, a display device <NUM>, a speaker <NUM>, a wireless communication interface <NUM>, an antenna switch <NUM>, an antenna <NUM>, a bus <NUM>, a battery <NUM>, and an auxiliary controller <NUM>.

The processor <NUM> may be, for example, a central processing unit (CPU) or a system on chip (SoC), and controls functions of an application layer and other layers of the smartphone <NUM>. The memory <NUM> includes a random access memory (RAM) and a read only memory (ROM), and stores programs executed by the processor <NUM> and data. The storage <NUM> can include a storage medium such as a semiconductor memory or a hard disk. The externally connected interface <NUM> is an interface for connecting an externally attached device such as a memory card or a universal serial bus (USB) device to the smartphone <NUM>.

The camera <NUM> has an image sensor, for example, a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) to generate captured images. The sensor <NUM> can include a sensor group including, for example, a positioning sensor, a gyro sensor, a geomagnetic sensor, an acceleration sensor, and the like. The microphone <NUM> converts sounds input to the smartphone <NUM> into audio signals. The input device <NUM> includes, for example, a touch sensor that detects touches on a screen of the display device <NUM>, a key pad, a keyboard, buttons, switches, and the like to receive manipulations or information inputs from a user. The display device <NUM> has a screen such as a liquid crystal display (LCD), or an organic light emitting diode (OLED) display to display output images of the smartphone <NUM>. The speaker <NUM> converts audio signals output from the smartphone <NUM> into sounds.

The wireless communication interface <NUM> supports one or more wireless LAN standards of IEEE <NUM>. 11a, 11b, <NUM>, 11n, 11ac, and 11ad to execute wireless LAN communication. The wireless communication interface <NUM> can communicate with another apparatus via a wireless LAN access point in the infrastructure mode. In addition, the wireless communication interface <NUM> can directly communicate with another apparatus in a direct communication mode, such as an ad hoc mode, Wi-Fi Direct, or the like. In Wi-Fi Direct (registered trademark), one of two terminals operates as an access point unlike in an ad hoc mode, but communication is performed directly between the terminals. The wireless communication interface <NUM> can typically have a baseband processor, an radio frequency (RF) circuit, a power amplifier, and the like. The wireless communication interface <NUM> may be a single-chip module on which a memory that stores a communication control program, a processor that executes the program, and a relevant circuit are integrated. The wireless communication interface <NUM> may support another kind of wireless communication scheme such as a short-range wireless communication scheme, a proximity wireless communication scheme, or the cellular communication scheme in addition to the wireless LAN scheme. The antenna switch <NUM> switches a connection destination of the antenna <NUM> for a plurality of circuits (for example, a circuit for another wireless communication scheme) included in the wireless communication interface <NUM>. The antenna <NUM> has a single or a plurality of antenna elements (for example, a plurality of antenna elements included in a MIMO antenna) and is used for transmission and reception of wireless signals from the wireless communication interface <NUM>.

Note that the smartphone <NUM> may include a plurality of antennas (for example, antennas for a wireless LAN or antennas for a proximity wireless communication scheme, or the like), without being limited to the example of <FIG>. In this case, the antenna switch <NUM> may be omitted from the configuration of the smartphone <NUM>.

The bus <NUM> connects the processor <NUM>, the memory <NUM>, the storage <NUM>, the externally connected interface <NUM>, the camera <NUM>, the sensor <NUM>, the microphone <NUM>, the input device <NUM>, the display device <NUM>, the speaker <NUM>, the wireless communication interface <NUM>, and the auxiliary controller <NUM> to one another. The battery <NUM> supplies electric power to each of the blocks of the smartphone <NUM> shown in <FIG> via power supply lines partially indicated by dashed lines in the drawing. The auxiliary controller <NUM> causes, for example, required minimum functions of the smartphone <NUM> to be operated in a sleep mode.

The wireless communication unit <NUM>, the data processing unit <NUM>, and the control unit <NUM> described with reference to <FIG> in the smartphone <NUM> shown in <FIG> may be mounted on the wireless communication interface <NUM>. At least some of the functions may be mounted on the processor <NUM> or the auxiliary controller <NUM>.

The smartphone <NUM> may operate as a wireless access point (software AP) when the processor <NUM> performs an access point function at an application level. The wireless communication interface <NUM> may have the wireless access point function.

<FIG> is a block diagram showing an example of a schematic configuration of a car navigation apparatus <NUM> to which the technology of the present disclosure can be applied. The car navigation apparatus <NUM> includes a processor <NUM>, a memory <NUM>, a global positioning system (GPS) module <NUM>, a sensor <NUM>, a data interface <NUM>, a content player <NUM>, a storage medium interface <NUM>, an input device <NUM>, a display device <NUM>, a speaker <NUM>, a wireless communication interface <NUM>, an antenna switch <NUM>, an antenna <NUM>, and a battery <NUM>.

The processor <NUM> may be, for example, a CPU or an SoC controlling a navigation function and other functions of the car navigation apparatus <NUM>. The memory <NUM> includes a RAM and a ROM storing programs executed by the processor <NUM> and data.

The GPS module <NUM> measures a position of the car navigation apparatus <NUM> (for example, latitude, longitude, and altitude) using GPS signals received from a GPS satellite. The sensor <NUM> can include a sensor group including, for example, a gyro sensor, a geomagnetic sensor, a barometric sensor, and the like. The data interface <NUM> is connected to an in-vehicle network <NUM> via, for example, a terminal that is not illustrated to acquire data generated on the vehicle side such as car speed data.

The content player <NUM> reproduces content stored in a storage medium (for example, a CD or a DVD) inserted into the storage medium interface <NUM>. The input device <NUM> includes, for example, a touch sensor that detects touches on a screen of the display device <NUM>, buttons, switches, and the like to receive manipulations or information inputs from a user. The display device <NUM> has a screen such as an LCD or an OLED display to display images of the navigation function or reproduced content. The speaker <NUM> outputs sounds of the navigation function or reproduced content.

The wireless communication interface <NUM> supports one or more wireless LAN standards of IEEE <NUM>. 11a, 11b, <NUM>, 11n, 11ac, and 11ad to execute wireless LAN communication. The wireless communication interface <NUM> can communicate with another apparatus via a wireless LAN access point in the infrastructure mode. In addition, the wireless communication interface <NUM> can directly communicate with another apparatus in a direct communication mode, such as an ad hoc mode, Wi-Fi Direct, or the like. The wireless communication interface <NUM> can typically have a baseband processor, an RF circuit, a power amplifier, and the like. The wireless communication interface <NUM> may be a single-chip module on which a memory that stores a communication control program, a processor that executes the program, and a relevant circuit are integrated. The wireless communication interface <NUM> may support another kind of wireless communication scheme such as a short-range wireless communication scheme, a proximity wireless communication scheme, or the cellular communication scheme in addition to the wireless LAN scheme. The antenna switch <NUM> switches a connection destination of the antenna <NUM> for a plurality of circuits included in the wireless communication interface <NUM>. The antenna <NUM> has a single or a plurality of antenna elements and is used for transmission and reception of wireless signals from the wireless communication interface <NUM>.

Note that the car navigation apparatus <NUM> may include a plurality of antennas, without being limited to the example of <FIG>. In this case, the antenna switch <NUM> may be omitted from the configuration of the car navigation apparatus <NUM>.

The battery <NUM> supplies electric power to each of the blocks of the car navigation apparatus <NUM> shown in <FIG> via power supply lines partially indicated by dashed lines in the drawing. In addition, the battery <NUM> accumulates electric power supplied from the vehicle.

The wireless communication unit <NUM>, the data processing unit <NUM>, and the control unit <NUM> described with reference to <FIG> in the car navigation apparatus <NUM> shown in <FIG> may be mounted on the wireless communication interface <NUM>. At least some of the functions may be mounted on the processor <NUM>.

Further, the wireless communication interface <NUM> may operate as the above-described AP <NUM> and may provide wireless connection to a terminal carried by a user getting in a vehicle.

Further, the technology of the present disclosure may be realized as an in-vehicle system (or a vehicle) <NUM> including one or more blocks of the above-described car navigation apparatus <NUM>, the in-vehicle network <NUM>, and a vehicle-side module <NUM>. The vehicle-side module <NUM> generates vehicle-side data such as a vehicle speed, the number of engine rotations, or failure information and outputs the generated data to the in-vehicle network <NUM>.

<FIG> is a block diagram showing an example of a schematic configuration of a wireless access point <NUM> to which the technology of the present disclosure can be applied. The wireless access point <NUM> includes a controller <NUM>, a memory <NUM>, an input device <NUM>, a display device <NUM>, a network interface <NUM>, a wireless communication interface <NUM>, an antenna switch <NUM>, and an antenna <NUM>.

The controller <NUM> may be, for example, a CPU or a digital signal processor (DSP) and operates various functions (for example, access restriction, routing, encryption, firewall, and log management) of the Internet Protocol (IP) layer and higher layers of the wireless access point <NUM>. The memory <NUM> includes a RAM and a ROM and stores a program to be executed by the controller <NUM> and various kinds of control data (for example, a terminal list, a routing table, an encryption key, security setting, and a log).

The input device <NUM> includes, for example, buttons or switches and receives manipulations from a user. The display device <NUM> includes an LED lamp or the like and displays operation status of the wireless access point <NUM>.

The network interface <NUM> is a wired communication interface that connects the wireless access point <NUM> to a wired communication network <NUM>. The network interface <NUM> may include a plurality of connection terminals. The wired communication network <NUM> may be a LAN such as Ethernet (registered trademark) or a wide area network (WAN).

The wireless communication interface <NUM> supports one or more wireless LAN standards of IEEE <NUM>. 11a, 11b, <NUM>, 11n, 11ac, and 11ad to provide a wireless connection to a terminal located nearby as an access point. The wireless communication interface <NUM> can typically have a baseband processor, an RF circuit, a power amplifier, and the like. The wireless communication interface <NUM> may be a single-chip module on which a memory that stores a communication control program, a processor that executes the program, and a relevant circuit are integrated. The antenna switch <NUM> switches a connection destination of the antenna <NUM> for a plurality of circuits included in the wireless communication interface <NUM>. The antenna <NUM> has a single antenna element or a plurality of antenna elements and is used for transmission and reception of wireless signals from the wireless communication interface <NUM>.

The wireless communication unit <NUM>, the data processing unit <NUM>, and the control unit <NUM> described with reference to <FIG> in the wireless access point <NUM> shown in <FIG> may be mounted on the wireless communication interface <NUM>. At least some of the functions may be mounted on the controller <NUM>.

As described above, in the present embodiment, the STA <NUM> can perform the data transmission according to the priority of the transmission data using the UL SU regardless of the UL MU. In addition, the STA <NUM> does not reset the backoff counter when the data transmission using the UL SU is performed after the UL MU, and thus it is possible to prevent the data transmission from being delayed due to the resetting of the backoff counter. In other words, the STA <NUM> can prevent the implementation of the UL SU from being delayed due to the implementation of the UL MU. The STA <NUM> and the AP <NUM> according to the present embodiment have compatibility with the STA and the AP employing the method of the related art. For example, the STA <NUM> and the AP <NUM> according to the present embodiment can correctly communicate with both the STA and the AP that perform random access control based on CSMA/CA using the method of the related art.

It should be understood by those skilled in the art that various modifications, combinations, subcombinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.

For example, steps in the operation of the STA <NUM> according to the present embodiment need not necessarily be performed chronologically in accordance with the order described in the flowcharts. For example, steps in the process of the STA <NUM> may be performed in an order different from the order described in the flowcharts or may be performed in parallel.

Further, some components of the STA <NUM> may be appropriately installed outside the STA <NUM>. Similarly, some components of the AP <NUM> may be appropriately installed outside the AP <NUM>.

Further, some functions of the STA <NUM> may be implemented by the control unit <NUM>. In other words, the control unit <NUM> may implement some functions of the wireless communication unit <NUM> or the data processing unit <NUM>. Similarly, some functions of the AP <NUM> may be implemented by the control unit <NUM>. In other words, the control unit <NUM> may implement some functions of the wireless communication unit <NUM> or the data processing unit <NUM>.

Claim 1:
A wireless device, operating as station (<NUM>), comprising:
a communication unit (<NUM>) configured to perform both multi-user spatial multiplex communication and single-user communication with a communication device operating as an access point (<NUM>);
a setting unit (<NUM>) configured to set a second waiting time for the single-user communication and a first waiting time for the multi-user spatial multiplex communication; and
a control unit (<NUM>) configured to count the second waiting time in a period in which the first waiting time is counted,
wherein
the communication unit (<NUM>) is configured to receive, from the communication device, a trigger frame causing transmission of data to the communication device through the multi-user spatial multiplex communication in accordance with the first waiting time,
the control unit (<NUM>) is configured to suspend counting the first waiting time in response to receiving the trigger frame and to restart to count the suspended first waiting time without resetting the first waiting time, based on a lapse of time for reception of a response frame from the communication device, wherein the response frame is responded to transmission of the data using the multi-user multiplex communication caused by the trigger frame, and
the communication unit (<NUM>) is further configured to retransmit the data to the communication device through the single-user communication after the second waiting time expired.