Patent Description:
In the past, in a system has been used in an information processing apparatus that uses wireless communication to exchange information (frames), a transmission suppression period for avoiding a collision is set in the communication of the frames between a plurality of information processing apparatuses. For example, an information processing apparatus has been proposed, the information processing apparatus configured to multiplex a plurality of frames by adding opposite direction permission information for permitting frame communication in the opposite direction to each of the plurality of frames and configured to transmit and receive data to and from an information processing apparatus that has received the frame (for example, see PTL <NUM>). In the related art, when the frame provided with the opposite direction permission information is transmitted, the transmission suppression period is set for another information processing apparatus not involved in the transmission and reception of data.

In the related art described above, there is a problem that the transmission suppression period set for another information processing apparatus is not reduced in a case where the transmission of data ends early when the time required for the transmission of data is shorter than expected. A system is used to solve the problem, in which the information processing apparatus that has transmitted the data transmits a frame for instructing reduction of the transmission suppression period to the other information processing apparatus to thereby reduce the set transmission suppression period. However, an information processing apparatus that cannot receive the frame for instructing the reduction of the transmission suppression period cannot reduce the transmission suppression period, and the wireless communication is restricted. Therefore, there is a problem of inequality between other information processing apparatuses in using wireless resources.

The present technique has been made in view of the circumstances, and an object of the present technique is to equally reduce transmission suppression periods set in information processing apparatuses to eliminate inequality in using wireless resources.

The present technique has been made to solve the problems. There are provided an information processing apparatus, a communication system, an information processing method and a corresponding program according to the appended claims.

The present technique can attain excellent advantageous effects of equally reducing transmission suppression periods set in information processing apparatuses to thereby eliminate inequality in using wireless resources. Note that the advantageous effects described here may not be limited, and the present technique may have any of the advantageous effects described in the present disclosure.

Hereinafter, a mode for carrying out the present technique (hereinafter, referred to as embodiment) will be described. The embodiment will be described in the following order.

<FIG> is a block diagram illustrating a functional configuration example of an information processing apparatus <NUM> according to an embodiment of the present technique.

The information processing apparatus <NUM> includes a data processing unit <NUM>, a signal processing unit <NUM>, a wireless interface unit <NUM>, an antenna <NUM>, a storage unit <NUM>, and a control unit <NUM>.

For example, the information processing apparatus <NUM> can be a fixed or mobile information processing apparatus having a wireless communication function. Here, the fixed information processing apparatus is, for example, an information processing apparatus, such as an access point (Access Point) and a base station, in a wireless LAN (Local Area Network) system. In addition, the mobile information processing apparatus is, for example, an information processing apparatus, such as a smartphone, a mobile phone, and a tablet terminal.

In addition, the information processing apparatus <NUM> has, for example, a communication function in compliance with a wireless LAN standard of IEEE (Institute of Electrical and Electronic Engineers) <NUM>. For example, the information processing apparatus <NUM> can have a communication function in compliance with a wireless LAN standard of IEEE <NUM>. In addition, examples of the wireless LAN that can be used include Wi-Fi (Wireless Fidelity), Wi-Fi Direct, Wi-Fi CERTIFIED Miracast specifications (technical specification name: Wi-Fi Display). In addition, other communication systems may be used to perform wireless communication.

In addition, the information processing apparatus <NUM> may be a device corresponding to, for example, MU-MIMO (Multi User MIMO). In that case, the information processing apparatus <NUM> can transmit information toward a plurality of devices at the same time. In addition, in the case where the information processing apparatus <NUM> transmits information toward a plurality of devices at the same time, the information processing apparatus <NUM> can receive CTS (Clear to Send) frames from a plurality of devices.

The data processing unit <NUM> is configured to process various types of data on the basis of control of the control unit <NUM>. For example, the data processing unit <NUM> applies an addition process of a MAC (Media Access Control) Header, an error detection code, or the like to data from an upper layer and generates a packet for wireless transmission. The data processing unit <NUM> then supplies the generated packet to the signal processing unit <NUM>.

In addition, for example, at reception of data, the data processing unit <NUM> applies a process of analyzing the header, detecting a packet error, and the like to a bit string received from the signal processing unit <NUM> and supplies the processed data to the upper layer. In addition, for example, the data processing unit <NUM> notifies the control unit <NUM> of an analysis result of the header, a detection result of a packet error, and the like.

The signal processing unit <NUM> is configured to execute various types of signal processing on the basis of control of the control unit <NUM>. For example, at transmission, the signal processing unit <NUM> encodes input data from the data processing unit <NUM> on the basis of a coding and modulation scheme set by the control unit <NUM> and adds a preamble and a PHY header. The signal processing unit <NUM> then supplies a transmission symbol stream obtained by the signal processing to the wireless interface unit <NUM>.

In addition, for example, at reception, the signal processing unit <NUM> detects a preamble and a PHY header of a reception symbol stream received from the wireless interface unit <NUM>, applies a decoding process to the stream, and supplies the data to the data processing unit <NUM>. In addition, for example, the signal processing unit <NUM> notifies the control unit <NUM> of a detection result of the PHY header and the like.

The wireless interface unit <NUM> is an interface for using wireless communication to connect to another information processing apparatus to transmit and receive various types of information on the basis of control of the control unit <NUM>. For example, at transmission, the wireless interface unit <NUM> converts an input from the signal processing unit <NUM> into an analog signal, amplifies and filters the signal, up-coverts the signal to a predetermined frequency, and sends out the signal to the antenna <NUM>.

In addition, for example, at reception, the wireless interface unit <NUM> applies opposite processing to an input from the antenna <NUM> and supplies the processing result to the signal processing unit <NUM>.

In addition, the transmission power of the data transmitted from the wireless interface unit <NUM> is controlled by the control unit <NUM>.

The storage unit <NUM> plays a role of a working area of data processing by the control unit <NUM> and functions as a storage medium that holds various types of data. For example, a storage medium, such as a non-volatile memory, a magnetic disk, an optical disk, and an MO (Magneto Optical) disk, can be used as the storage unit <NUM>. Note that, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory) or an EPROM (Erasable Programmable ROM) can be used as the non-volatile memory. In addition, for example, a hard disk or a disc-shaped magnetic disk can be used as the magnetic disk. In addition, for example, a CD (Compact Disc), a DVD-R (Digital Versatile Disc Recordable), or a BD (Blu-ray (registered trademark) Disc) can be used as the optical disk.

The control unit <NUM> is configured to control respective reception operation and transmission operation of the data processing unit <NUM>, the signal processing unit <NUM>, and the wireless interface unit <NUM>. For example, the control unit <NUM> transfers information between the components, sets communication parameters, and schedules packets in the data processing unit <NUM>.

In addition, for example, the control unit <NUM> controls transmission of an inducement frame for causing another communication device to transmit a transmission suppression period reduction (CF_End) frame for reducing a transmission suppression period (NAV (Network Allocation Vector)) that is a period of suppressing frame transmission. That is, the control unit <NUM> transmits the inducement frame to induce another communication device that receives the frame to transmit a CF_End frame. Details of the configurations of the CF_End frame and the inducement frame will be described later.

In addition, for example, in a case where the control unit <NUM> receives an inducement frame, the control unit <NUM> controls transmission of a CF_End frame on the basis of the inducement frame.

<FIG> is a diagram illustrating an example of a system configuration of a communication system <NUM> according to the embodiment of the present technique.

The communication system <NUM> is a wireless network including an information processing apparatus (STA A) <NUM>, an information processing apparatus (STA B) <NUM>, an information processing apparatus (STA1) <NUM>, an information processing apparatus (STA2) <NUM>, and an information processing apparatus (STA3) <NUM>. Note that in <FIG>, each information processing apparatus (STA) is indicated by a triangle. In addition, a radio wave reaching range <NUM> of the information processing apparatus (STA A) <NUM> is indicated by a circle with a dotted line around the information processing apparatus (STA A) <NUM>. In addition, a radio wave reaching range <NUM> of the information processing apparatus (STA B) <NUM> is indicated by a circle with a dotted line around the information processing apparatus (STA B) <NUM>.

Here, a hidden terminal generated in an environment including a plurality of different networks will be described with reference to <FIG>.

For example, a case in which the information processing apparatus (STA A) <NUM> transmits a frame toward the information processing apparatus (STA B) <NUM> will be illustrated. In this case, the information processing apparatus (STA2) <NUM> is outside of the radio wave reaching range <NUM> of the information processing apparatus (STA A) <NUM> and cannot detect the frame from the information processing apparatus (STA A) <NUM>. Therefore, there may be a case in which the information processing apparatus (STA2) <NUM> determines that the radio band is not used and starts frame transmission from the information processing apparatus (STA2) <NUM>. In this case, while the frame is transmitted from the information processing apparatus (STA A) <NUM>, a frame is also transmitted from the information processing apparatus (STA2) <NUM>. In this way, if the frame transmission from the information processing apparatus (STA A) <NUM> and the frame transmission from the information processing apparatus (STA2) <NUM> are performed in the same time zone, the frame from the information processing apparatus (STA A) <NUM> and the frame from the information processing apparatus (STA2) <NUM> may collide, and the information processing apparatus (STA B) <NUM> may fail to receive a desired signal.

To prevent the failure in the signal reception, a system called NAV is adopted in IEEE <NUM>. <FIG> illustrates this example.

<FIG> is a diagram illustrating an example of setting the NAV as a basis of the present technique. Note that the horizontal axis illustrated in <FIG> indicates a time axis. In addition, above the time axis corresponding to the information processing apparatus (STA A) <NUM> and the information processing apparatus (STA B) <NUM> in <FIG>, data to be transmitted is indicated by rectangles in which the content is written inside. In addition, above the time axis corresponding to the information processing apparatus (STA2) <NUM>, detected data is indicated by rectangles in which the content is written inside.

<FIG> illustrates an example of a case in which the NAV is set in the information processing apparatus (STA1) <NUM> and the information processing apparatus (STA2) <NUM> individually on the basis of an RST frame and a CTS frame transmitted from the information processing apparatus (STA B) <NUM>.

First, the information processing apparatus (STA A) <NUM> transmits an RTS frame to the information processing apparatus (STA B) <NUM> before transmitting the data toward the information processing apparatus (STA B) <NUM> (<NUM>). In the RTS frame, the time (transmission suppression time) for setting the NAV is stored in Duration. In addition, the information processing apparatus (STA A) <NUM> sets the NAV based on virtual carrier sense throughout the time stored in the Duration of the RTS frame (<NUM>).

In addition, in the case where the information processing apparatus (STA B) <NUM> receives the RTS frame, the information processing apparatus (STA B) <NUM> transmits a CTS frame to the information processing apparatus (STA A) <NUM> (<NUM>) in response to the RTS frame. The time (transmission suppression time) for setting the NAV is stored in Duration of the CTS frame. In addition, the information processing apparatus (STA B) <NUM> sets the NAV based on virtual carrier sense throughout the time stored in the Duration of the CTS frame (<NUM>).

In this way, the information processing apparatus (STA A) <NUM> and the information processing apparatus (STA B) <NUM> exchange the RTS frame and the CTS frame (<NUM> and <NUM>). In addition, the information for the device (peripheral device) that has received each frame to set the transmission suppression period is stored in the RTS frame and the CTS frame.

Here, the information processing apparatus (STA1) <NUM> can detect the RTS frame transmitted from the information processing apparatus (STA A) <NUM> (<NUM>), and the information processing apparatus (STA1) <NUM> sets the NAV (<NUM>). In addition, the information processing apparatus (STA2) <NUM> can detect the CTS frame transmitted from the information processing apparatus (STA B) <NUM> (<NUM>), and the information processing apparatus (STA2) <NUM> sets the NAV (<NUM>).

In this way, in the period in which the NAV is set (<NUM> and <NUM>), the information processing apparatus (STA A) <NUM> transmits data (Data) to the information processing apparatus (STA B) <NUM> (<NUM>). In addition, an acknowledgement (ACK) frame is exchanged as necessary (<NUM>).

In addition, the information processing apparatus (STA1) <NUM> that has received the RTS frame suppresses the transmission from the information processing apparatus (STA1) <NUM> until the frame exchange between the information processing apparatus (STA A) <NUM> and the information processing apparatus (STA B) <NUM> is finished (<NUM>). Similarly, the information processing apparatus (STA2) <NUM> that has received the CTS frame suppresses the transmission from the information processing apparatus (STA2) <NUM> until the frame exchange between the information processing apparatus (STA A) <NUM> and the information processing apparatus (STA B) <NUM> is finished. Therefore, the collision of packets described above can be avoided.

At this time, the time required for the Data transmission changes according to the surrounding environment of the information processing apparatus (STA A) <NUM>. For example, in a case where the information processing apparatus (STA B) <NUM> is near the information processing apparatus (STA A) <NUM>, the Data can be transmitted at a high MCS (Modulation and Coding Scheme). In such a case, the time required for the Data transmission becomes short, and the NAV is in excess. Therefore, a system of reducing the set NAV is proposed.

<FIG> is a diagram illustrating an example of reducing the set NAV as a basis of the present technique. In <FIG>, after the ACK frame is transmitted from the information processing apparatus (STA B) <NUM> (<NUM>), the information processing apparatus (STA A) <NUM> can transmit a CF_End frame to surrounding information processing apparatuses to reduce the NAVs set in the information processing apparatuses.

In <FIG>, the information processing apparatus (STA1) <NUM> detects the CF_End frame (<NUM>) and cancels the NAV (<NUM>), and the NAV (<NUM>) is reduced. As a result, transmission from the information processing apparatus (STA1) <NUM> is possible in the subsequent period. In this way, the CF_End frame can be transmitted to effectively use wireless resources.

On the other hand, in <FIG>, the information processing apparatus (STA2) <NUM> that cannot receive the CF_End frame from the information processing apparatus (STA A) <NUM> cannot reduce the set NAV (<NUM>). Therefore, the information processing apparatus (STA2) <NUM> is disadvantaged during a period <NUM> in <FIG> compared to the information processing apparatus (STA1) <NUM>.

In this case, the information processing apparatus (STA B) <NUM> that has received the CF_End frame can respond to the CF_End frame, and the information processing apparatus (STA B) <NUM> can reduce the NAV. However, the NAV cannot be reduced at the same time as the information processing apparatus (STA1) <NUM>, and the disadvantage of the information processing apparatus (STA2) <NUM> is not eliminated.

Therefore, in the embodiment of the present technique, the information processing apparatus (STA A) <NUM> transmits the inducement frame to induce another information processing apparatus to transmit the CF_End frame. As a result, the CF_End frame is transmitted from a plurality of information processing apparatuses, and the disadvantage described above can be eliminated.

<FIG> is a diagram illustrating an example of the reduction of the NAV by transmitting the inducement frame according to the embodiment of the present technique. In <FIG>, after the ACK is transmitted from the information processing apparatus (STA B) <NUM> (<NUM>), the information processing apparatus (STA A) <NUM> transmits an inducement frame (Trigger frame) to the information processing apparatus (STA B) <NUM> (<NUM>). The Trigger frame is a frame for inducing the transmission of the CF_End frame. The information processing apparatus (STA B) <NUM> that has received the Trigger frame transmits a CF_End frame after a predetermined time (<NUM>). This can reduce the NAV of an information processing apparatus, specifically, the information processing apparatus (STA2) <NUM>, around the information processing apparatus (STA B) <NUM>.

In this way, in the transmission of the Data frame in which the NAV is set, the information processing apparatus (STA A) <NUM> that has first transmitted the frame for setting the NAV (transmission <NUM> and <NUM> of RTS frame in <FIG>) transmits the Trigger frame.

In this case, the information processing apparatus (STA1) <NUM> that has transmitted the Trigger frame also transmits the CF_End frame after a predetermined time (<NUM>). This can reduce the NAV of an information processing apparatus, specifically, the information processing apparatus (STA1) <NUM>, around the information processing apparatus (STA A) <NUM>.

In this case, the information processing apparatus (STA A) <NUM> and the information processing apparatus (STA B) <NUM> start to transmit the CF_End frames at the same time (<NUM> and <NUM>). In addition, the CF_End frames are transmitted on the basis of the same transmission rate. Furthermore, the information processing apparatus (STA A) <NUM> transmits the CF_End frame in the same configuration as the CF_End frame transmitted by the information processing apparatus (STA B) <NUM>. As a result, for example, an information processing apparatus, such as the information processing apparatus (STA3) <NUM> in <FIG>, that can receive two CF_End frames transmitted by the information processing apparatus (STA A) <NUM> and the information processing apparatus (STA B) <NUM> can receive the CF_End frames as a single CF_End frame.

Note that in the communication of the wireless communication system in compliance with IEEE <NUM>, the transmission and the reception of the frames cannot be completely synchronized. It is also difficult to make the transmission rates of a plurality of information processing apparatuses completely equal. Therefore, an error occurs in the timing of the start of the transmission of the CF_End frames by the information processing apparatus (STA A) <NUM> and the information processing apparatus (STA B) <NUM> described above. There is also a difference (error) between the transmission rates of the CF_End frames in the information processing apparatus (STA A) <NUM> and the information processing apparatus (STA B) <NUM>. Even in the case of such an error, a plurality of information processing apparatuses can simultaneously transmit the CF_End frames in the same configuration at the same transmission rate, and another information processing apparatus can receive the CF_End frames as a single CF-End frame.

The information processing apparatus (STA A) <NUM> transmits the Trigger frame to a plurality of information processing apparatuses. The situation will be described with reference to <FIG>.

<FIG> is a diagram illustrating another example of the reduction of the NAV by transmitting the inducement frame according to the embodiment of the present technique. <FIG> depicts a case of a spatial/frequency-division multiplexing sequence in which frames are transmitted to a plurality of information processing apparatuses at the same time.

In <FIG>, the information processing apparatus (STA A) <NUM> simultaneously transmits a Multi RTS frame to the information processing apparatus (STA B) <NUM> and the information processing apparatus (STA3) <NUM> instead of the RST frame (<NUM> and <NUM>). Next, the information processing apparatus (STA B) <NUM> and the information processing apparatus (STA3) <NUM> simultaneously transmit CTS frames to the information processing apparatus (STA A) <NUM> (<NUM> and <NUM>). Next, the information processing apparatus (STA A) <NUM> simultaneously transmits a Data frame to the information processing apparatus (STA B) <NUM> and the information processing apparatus (STA3) <NUM> (<NUM> and <NUM>). The Data frame is transmitted in a spatial multiplexing or frequency-division multiplexing sequence.

Next, the information processing apparatus (STA B) <NUM> and the information processing apparatus (STA3) <NUM> simultaneously transmit ACK frames to the information processing apparatus (STA A) <NUM> (<NUM> and <NUM>). Different channels are used to transmit the ACK frames. The information processing apparatus (STA A) <NUM> that has received the ACK frames simultaneously transmits a Trigger frame to the information processing apparatus (STA B) <NUM> and the information processing apparatus (STA3) <NUM> (<NUM> and <NUM>). The information processing apparatus (STA B) <NUM> and the information processing apparatus (STA3) <NUM> that have received the Trigger frame simultaneously transmit CF_End frames (<NUM> and <NUM>).

In this way, the Trigger frame is transmitted as an inducement frame to induce a plurality of information processing apparatuses to simultaneously transmit the CF_End frames.

<FIG> is a diagram illustrating a configuration example of the inducement frame according to the embodiment of the present technique. <FIG> depicts a configuration example of the Trigger frame described in <FIG>. The Trigger frame in <FIG> includes a PHY Header <NUM>, a Frame Type <NUM>, a Duration <NUM>, an Rx Address <NUM>, a Tx Address <NUM>, and an Allowed Frame <NUM>. In addition, the Trigger frame in <FIG> further includes a Triggered STA <NUM> and an FCS <NUM>.

Note that the Frame Type <NUM>, the Duration <NUM>, the Rx Address <NUM>, and the Tx Address <NUM> form a MAC Header. Information (Frame Type) indicating the purpose of the transmission of the frame is stored in the MAC Header. Information (UL Trigger) for permitting the target information processing apparatus to communicate in the opposite direction is described in the Trigger frame in <FIG>.

A BSS (Basic Service Set), a Color, a Length, and the like are stored in the PHY Header <NUM>.

The UL Trigger is described in the Frame Type <NUM> as described above.

Duration information for setting the NAV is described in the Duration <NUM>.

Address information of the information processing apparatus that should receive the frame is described in the Rx Address <NUM>. A broadcast address for broadcasting can be described as the address information to allow a plurality of information processing apparatuses to receive the Trigger frame. That is, the broadcast address is described in the Rx Address <NUM> of the Trigger frame described in <FIG>.

Address information of the information processing apparatus as a sender of the frame is described in the Tx Address <NUM>.

The type of the frame to be transmitted in the opposite direction is described in the Allowed Frame <NUM>. The CF_End frame is designated in the Trigger frame of <FIG>.

Addresses (STA ID) <NUM> of the information processing apparatuses that transmit the frames in the opposite direction are described in the Triggered STA <NUM>. In <FIG>, the addresses of the information processing apparatus (STA B) <NUM> and the information processing apparatus (STA3) <NUM> are described.

An error detection code is stored in the FCS <NUM>.

Note that the information is an example, and other information may be stored in the frame.

<FIG> is a diagram illustrating a configuration example of the transmission suppression period reduction frame according to the embodiment of the present technique. <FIG> depicts a configuration example of the CF_End frame described in <FIG>. The CF_End frame of <FIG> includes a PHY Header <NUM>, a Frame Type <NUM>, a Duration <NUM>, an Rx address <NUM>, a Tx Address <NUM>, and an FCS <NUM>.

Note that the Frame Type <NUM>, the Duration <NUM>, the Rx Address <NUM>, and the Tx address <NUM> form a MAC Header.

The Frame Type <NUM> indicates that the frame is a CF_End frame.

A value "<NUM>" is described in the Duration <NUM>.

A broadcast address is described in the Rx Address <NUM>.

The address of the information processing apparatus that has transmitted the Trigger frame is described in the Tx Address <NUM>, for example. This is for causing a plurality of information processing apparatuses to transmit CF End frames with the same content. This can be defined by, for example, a standard.

The PHY Header <NUM> and the FCS <NUM> are similar to the PHY Header <NUM> and the FCS <NUM> described in <FIG>, and the description will not be repeated.

<FIG> is a diagram illustrating an example of a processing procedure of a data transmission process according to the embodiment of the present technique. The process of <FIG> is a process executed when the information processing apparatus transmits data. Specifically, the information processing apparatus (STA A) <NUM> described in <FIG> executes the process.

First, the control unit <NUM> transmits an RTS frame (step S801). As a result, a transmission suppression period (<NUM> in <FIG>) is set. Next, the control unit <NUM> waits until the control unit <NUM> receives a CTS frame (step S802). If the control unit <NUM> receives a CTS frame (step S802: Yes), the control unit <NUM> transmits a Data frame (step S803). Next, the control unit <NUM> waits until the control unit <NUM> receives an ACK frame (step S804). If the control unit <NUM> receives an ACK frame (step S804: Yes), the control unit <NUM> determines whether or not there is transmission Data (step S805). This can be determined on the basis of, for example, whether or not there is Data to be further transmitted to a transmission buffer.

If there is transmission Data (step S805: Yes), the control unit <NUM> determines whether or not the remaining time of the transmission suppression period is equal to or greater than a threshold <NUM> (step S806). Here, the threshold <NUM> is a threshold of the remaining time for determining whether or not a Data frame and an ACK frame can be transmitted and received. If the remaining time is equal to or greater than the threshold <NUM> (step S806: Yes), the control unit <NUM> executes the process from step S803 again. If the remaining time is smaller than the threshold <NUM> (step S806: No), the control unit <NUM> moves to a process of step S807. On the other hand, if there is no transmission Data in step S805 (step S805: No), the control unit <NUM> moves to the process of step S807.

In step S807, the control unit <NUM> determines whether or not the remaining time of the transmission suppression period is equal to or greater than a threshold <NUM> (step S807). Here, the threshold <NUM> is a threshold of the remaining time for determining whether or not an inducement frame and a transmission suppression period reduction frame can be transmitted. If the remaining time is equal to or greater than the threshold <NUM> (step S807: Yes), the control unit <NUM> transmits an inducement frame (step S808). Specifically, the control unit <NUM> transmits the Trigger frame described in <FIG>. Next, the control unit <NUM> transmits a transmission suppression period reduction frame after a predetermined time (step S809). Specifically, the control unit <NUM> transmits a CF_End frame described in <FIG>. Here, the predetermined time can be a time determined by a standard. Subsequently, the control unit <NUM> ends the data transmission process.

On the other hand, if the remaining time of the transmission suppression period is smaller than the threshold <NUM> in step S807 (step S807: No), the control unit <NUM> skips the process of steps S808 and S809 and ends the data transmission process.

<FIG> is a diagram illustrating an example of a processing procedure of a response process according to the embodiment of the present technique. The process of <FIG> is a process executed by an information processing apparatus that has received an RTS frame. Specifically, the information processing apparatus (STA B) <NUM> described in <FIG> executes the process.

First, the control unit <NUM> waits until the control unit <NUM> receives an RTS frame (step S851). If the control unit <NUM> receives an RTS frame (step S851: Yes), the control unit <NUM> transmits a CTS frame (step S852). As a result, a transmission suppression period (<NUM> in <FIG>) is set.

Subsequently, the control unit <NUM> receives a Data frame (step S853). Next, the control unit <NUM> transmits an ACK frame (step S854). Next, the control unit <NUM> determines whether or not the control unit <NUM> has received an inducement frame (Trigger frame) (step S858). If the control unit <NUM> has received an inducement frame (step S858: Yes), the control unit <NUM> transmits a transmission suppression period reduction frame (CF_End frame) after a predetermined time (step S859) and ends the response process.

In this way, the information processing apparatus can transmit the CF_End frame in a case where the information processing apparatus receives a Trigger frame from another communication device that has transmitted a frame (RTS frame) for setting the NAV.

On the other hand, if the control unit <NUM> has not received an inducement frame in step S858 (step S858: No), the control unit <NUM> determines whether or not a transmission suppression period has passed (step S855). If the transmission suppression period has not passed (step S855: No), the control unit <NUM> executes the process from step S858 again. If the transmission suppression period has passed (step S855: Yes), the control unit <NUM> ends the response process.

In this way, according to the embodiment of the present technique, the inducement frame can be transmitted to cause another information processing apparatus to transmit the transmission suppression period reduction frame, and the set NAVs can be reduced substantially at the same time. As a result, the transmission suppression periods set in other information processing apparatuses can be equally reduced, and the inequality in using the wireless resources can be eliminated.

The technique according to the present disclosure can be applied to various products. For example, the information processing apparatus <NUM> may be realized as a mobile terminal, such as a smartphone, a tablet PC (Personal Computer), a notebook PC, a mobile game terminal, and a digital camera, a fixed terminal, such as a television receiver, a printer, a digital scanner, and a network storage, or an in-vehicle terminal, such as a car navigation apparatus. The information processing apparatus <NUM> may also be realized as a terminal (also called MTC (Machine Type Communication) terminal) that performs M2M (Machine To Machine) communication, such as a smart meter, a vending machine, a remote monitoring apparatus, and a POS (Point Of Sale) terminal. The information processing apparatus <NUM> may also be a wireless communication module mounted on these terminals (for example, integrated circuit module including one die).

On the other hand, the information processing apparatus <NUM> may be realized as, for example, a wireless LAN access point (also called wireless base station) with a router function or without a router function. The information processing apparatus <NUM> and each information processing apparatus (STA) may also be realized as a mobile wireless LAN router. The information processing apparatus <NUM> may also be a wireless communication module mounted on these apparatuses (for example, integrated circuit module including one die).

<FIG> is a block diagram illustrating an example of a schematic configuration of a smartphone <NUM> to which the technique according to the present disclosure can be applied. The smartphone <NUM> includes a processor <NUM>, a memory <NUM>, a storage <NUM>, an external connection interface <NUM>, a camera <NUM>, a sensor <NUM>, a microphone <NUM>, an 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 CPU (Central Processing Unit) or a SoC (System on Chip), and the processor <NUM> controls functions of an application layer and other layers of the smartphone <NUM>. The memory <NUM> includes a RAM (Random Access Memory) and a ROM (Read Only Memory) and stores programs and data executed by the processor <NUM>. The storage <NUM> can include a storage medium, such as a semiconductor memory and a hard disk. The external connection interface <NUM> is an interface for connecting an external device, such as a memory card and a USB (Universal Serial Bus) device, to the smartphone <NUM>.

The camera <NUM> includes, for example, an imaging element, such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor), and generates a captured image. The sensor <NUM> can include, for example, a sensor group, such as a positioning sensor, a gyrosensor, a geomagnetic sensor, and an acceleration sensor. The microphone <NUM> converts sound input to the smartphone <NUM> into a sound signal. The input device <NUM> includes, for example, a touch sensor that detects a touch on a screen of the display device <NUM>, a key pad, a keyboard, a button, a switch, or the like and receives an operation or an input of information from the user. The display device <NUM> includes a screen, such as a liquid crystal display (LCD) and an organic light-emitting diode (OLED) display, and displays an output image of the smartphone <NUM>. The speaker <NUM> converts a sound signal output from the smartphone <NUM> into sound.

The wireless communication interface <NUM> supports one or more wireless LAN standards, such as IEEE <NUM>. 11a, 11b, <NUM>, 11n, 11ac, and 11ad, and executes wireless communication. The wireless communication interface <NUM> can communicate with another apparatus through a wireless LAN access point in an infrastructure mode. Furthermore, the wireless communication interface <NUM> can directly communicate with another apparatus in a direct communication mode, such as an ad hoc mode and Wi-Fi Direct. Note that although one of two terminals operates as an access point in the Wi-Fi Direct unlike in the ad hoc mode, the terminals directly communicate with each other. The wireless communication interface <NUM> can typically include a baseband processor, an RF (Radio Frequency) circuit, a power amplifier, and the like. The wireless communication interface <NUM> may be a one-chip module in which a memory that stores a communication control program, a processor that executes the program, and related circuits are integrated. The wireless communication interface <NUM> may support other types of wireless communication systems, such as a short-range wireless communication system, a near-field wireless communication system, and a cellular communication system, in addition to the wireless LAN system. The antenna switch <NUM> switches destinations of the antenna <NUM> between a plurality of circuits (for example, circuits for different wireless communication systems) included in the wireless communication interface <NUM>. The antenna <NUM> includes a single or a plurality of antenna elements (for example, a plurality of antenna elements included in a MIMO antenna), and the antenna <NUM> is used for transmission and reception of radio signals through the wireless communication interface <NUM>.

Note that the smartphone <NUM> is not limited to the example of <FIG>, and the smartphone <NUM> may include a plurality of antennas (for example, an antenna for wireless LAN, an antenna for near-field wireless communication system, and the like). In that case, the antenna switch <NUM> may be excluded from the configuration of the smartphone <NUM>.

The bus <NUM> mutually connects the processor <NUM>, the memory <NUM>, the storage <NUM>, the external connection 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>. The battery <NUM> supplies power to each block of the smartphone <NUM> illustrated in <FIG> through power feed lines partially indicated by dotted lines in <FIG>. The auxiliary controller <NUM> causes the smartphone <NUM> to operate minimum required functions in a sleep mode, for example.

In the smartphone <NUM> illustrated in <FIG>, the control unit <NUM> described with reference to <FIG> may be implemented in the wireless communication interface <NUM>. In addition, at least some of the functions may be implemented in the processor <NUM> or the auxiliary controller <NUM>. For example, the control unit <NUM> can transmit the inducement frame to improve the use efficiency of the wireless resources, and the power consumption of the battery <NUM> can be reduced.

Note that the processor <NUM> may execute an access point function in an application level, and the smartphone <NUM> may operate as a wireless access point (software AP). In addition, the wireless communication interface <NUM> may have a wireless access point function.

<FIG> is a block diagram illustrating an example of a schematic configuration of a car navigation apparatus <NUM> to which the technique according to the present disclosure can be applied. The car navigation apparatus <NUM> includes a processor <NUM>, a memory <NUM>, a GPS (Global Positioning System) 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 a SoC, and the processor <NUM> controls a navigation function and other functions of the car navigation apparatus <NUM>. The memory <NUM> includes a RAM and a ROM and stores programs and data executed by the processor <NUM>.

The GPS module <NUM> uses a GPS signal received from a GPS satellite to measure the position (for example, latitude, longitude, and altitude) of the car navigation apparatus <NUM>. The sensor <NUM> can include, for example, a sensor group, such as a gyrosensor, a geomagnetic sensor, and a pressure sensor. The data interface <NUM> is connected to an in-vehicle network <NUM> through, for example, a terminal not illustrated, and the data interface <NUM> acquires data, such as vehicle speed data, generated on the vehicle side.

The content player <NUM> reproduces content stored in a storage medium (for example, a CD or a DVD) inserted to the storage medium interface <NUM>. The input device <NUM> includes, for example, a touch sensor that detects a touch on a screen of the display device <NUM>, a button, a switch, or the like and receives an operation or an input of information from the user. The display device <NUM> includes a screen, such as an LCD and an OLED display, and displays an image of the navigation function or the content to be reproduced. The speaker <NUM> outputs sound of the navigation function or the content to be reproduced.

The wireless communication interface <NUM> supports one or more wireless LAN standards, such as IEEE <NUM>. 11a, 11b, <NUM>, 11n, 11ac, and 11ad, and executes wireless communication. The wireless communication interface <NUM> can communicate with another apparatus through a wireless LAN access point in an 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 and Wi-Fi Direct. The wireless communication interface <NUM> can typically include a baseband processor, an RF circuit, a power amplifier, and the like. The wireless communication interface <NUM> may be a one-chip module in which a memory that stores a communication control program, a processor that executes the program, and related circuits are integrated. The wireless communication interface <NUM> may support other types of wireless communication systems, such as a short-range wireless communication system, a near-field wireless communication system, and a cellular communication system, in addition to the wireless LAN system. The antenna switch <NUM> switches destinations of the antenna <NUM> between a plurality of circuits included in the wireless communication interface <NUM>. The antenna <NUM> includes a single or a plurality of antenna elements, and the antenna <NUM> is used for transmission and reception of radio signals through the wireless communication interface <NUM>.

Note that the car navigation apparatus <NUM> is not limited to the example of <FIG>, and the car navigation apparatus <NUM> may include a plurality of antennas. In that case, the antenna switch <NUM> may be excluded from the configuration of the car navigation apparatus <NUM>.

The battery <NUM> supplies power to each block of the car navigation apparatus <NUM> illustrated in <FIG> through power lines partially indicated by dotted lines in <FIG>. The battery <NUM> also accumulates power fed from the vehicle side.

In the car navigation apparatus <NUM> illustrated in <FIG>, the control unit <NUM> described with reference to <FIG> may be implemented in the wireless communication interface <NUM>. In addition, at least some of the functions may be implemented in the processor <NUM>. For example, the car navigation apparatus <NUM> can transmit the inducement frame to improve the use efficiency of the wireless resources.

In addition, the wireless communication interface <NUM> may operate as the information processing apparatus <NUM> to provide wireless connection to the terminal possessed by the user riding on the vehicle.

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

<FIG> is a block diagram illustrating an example of a schematic configuration of a wireless access point <NUM> to which the technique according to 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 DSP (Digital Signal Processor), and the controller <NUM> operates various functions (for example, access restriction, routing, encryption, firewall, log management, and the like) of layers higher than an IP (Internet Protocol) layer of the wireless access point <NUM>. The memory <NUM> includes a RAM and a ROM and stores programs executed by the controller <NUM> and various control data (for example, terminal list, routing table, encryption key, security setting, log, and the like).

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

The network interface <NUM> is a wired communication interface for connection of 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 may be a WAN (Wide Area Network).

The wireless communication interface <NUM> supports one or more wireless LAN standards, such as IEEE <NUM>. 11a, 11b, <NUM>, 11n, 11ac, and 11ad, and serves as an access point to provide wireless connection to neighboring terminals. The wireless communication interface <NUM> can typically include a baseband processor, an RF circuit, a power amplifier, and the like. The wireless communication interface <NUM> may be a one-chip module in which a memory that stores a communication control program, a processor that executes the program, and related circuits are integrated. The antenna switch <NUM> switches destinations of the antenna <NUM> between a plurality of circuits included in the wireless communication interface <NUM>. The antenna <NUM> includes a single or a plurality of antenna elements, and the antenna <NUM> is used for transmission and reception of radio signals through the wireless communication interface <NUM>.

In the wireless access point <NUM> illustrated in <FIG>, the control unit <NUM> described with reference to <FIG> may be implemented in the wireless communication interface <NUM>. In addition, at least some of the functions may be implemented in the controller <NUM>. For example, the wireless access point <NUM> can transmit the inducement frame to improve the use efficiency of the wireless resources.

Note that the embodiment described above illustrates an example for embodying the present technique, and the matters in the embodiment and the matters used to specify the invention in the claims correspond to each other. Similarly, the matters used to specify the invention in the claims and the matters with the same names in the embodiment of the present technique correspond to each other.

In addition, the processing procedures described in the embodiment may be regarded as a method including the series of procedures, and the processing procedures may be regarded as a program for causing a computer to execute the series of procedures or as a recording medium storing the program. Examples of the recording medium that can be used include a CD (Compact Disc), an MD (MiniDisc), a DVD (Digital Versatile Disc), a memory card, and a Blu-ray (registered trademark) Disc.

Claim 1:
An information processing apparatus (<NUM>; <NUM>) comprising:
a control unit (<NUM>) configured to transmit an inducement frame for causing a plurality of communication devices to transmit respective transmission suppression period reduction frames for reducing a transmission suppression period,
wherein the inducement frame includes addresses of the plurality of communication devices to transmit respective transmission suppression period reduction frames,
wherein
the control unit (<NUM>) is further configured to transmit a transmission suppression period reduction frame to another communication device after the transmission of the inducement frame.