Communication apparatus, control method, and program

Abstract

To efficiently utilize frequency resources in a communication system using a communication link composed of a plurality of channels.SOLUTION: A communication apparatus compliant with IEEE 802.11 standards series is configured to perform communication, in one communication link composed of a first channel to be used for obtaining a transmission right and at least one second channel which is different from the first channel, using one of a first communication scheme using at least the first channel and a second communication scheme using the one or more second channels without using the first channel in a period in which the first channel is unavailable. The communication apparatus determines, when a frame to be transmitted is a predetermined frame in a control communication that involves receiving another frame from another communication device, not to transmit the frame to be transmitted during the period.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a communication control technique in a communication device capable of communicating using a communication link made up of a plurality of channels. [Background technology]

[0002] In recent years, the increase in data traffic has led to the development of communication technologies such as wireless local area networks (WLANs). The IEEE (Institute of Electrical and Electronic Engineers) 802.11 standard series is known as the primary WLAN communication standard. The IEEE 802.11 series includes the IEEE 802.11a / b / g / n / ac / ax / be standards. To further improve communication reliability, the IEEE 802.11bn standard is being developed as the successor to the IEEE 802.11be standard. The IEEE 802.11 Working Group (WG), which is formulating the IEEE 802.11bn standard, is defining the goals and scope of the standard in the UHR SG, and the TGbn will specify the detailed technical content to be included in the standard. UHR SG stands for Ultra High Reliability Study Group. TGbn is also an abbreviation for Task Group bn.

[0003] As one of the candidates for the technology to be included in the IEEE802.11bn standard, a technology for efficiently utilizing frequency resources in a communication method using a communication link consisting of multiple channels is being considered. For example, Patent Document 1 describes a technology for performing communication using other channels when the primary channel used to acquire the transmission right cannot be used. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 1,1696,353 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a technique for more efficiently utilizing frequency resources in a communication system that uses a communication link consisting of multiple channels. [Means for solving the problem]

[0006] A communication device according to one embodiment of the present invention is a communication device that communicates in accordance with the IEEE 802.11 standard series, and has a communication means that communicates in a single communication link consisting of a first channel used to acquire a transmission right and one or more second channels different from the first channel, using either a first communication method that uses at least the first channel, or a second communication method that uses one or more of the second channels without using the first channel during a period when the first channel cannot be used, and the communication means determines not to transmit a frame to be transmitted during the period when the frame to be transmitted is a specified frame in a communication involving the reception of another frame from another communication device. [Effects of the Invention]

[0007] According to the present invention, it is possible to more efficiently utilize frequency resources in a communication system that uses a communication link made up of multiple channels. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. [Figure 2] FIG. 2 is a schematic diagram illustrating an example of a time chart when a communication device transmits data. [Figure 3] FIG. 2 illustrates an example of a hardware configuration of a communication device. [Figure 4] FIG. 2 illustrates an example of a functional configuration of a communication device. [Figure 5] FIG. 10 is a diagram illustrating an example of a processing flow for determining whether a frame can be transmitted. [Figure 6] FIG. 10 is a diagram illustrating an example of a processing flow for determining whether or not to transmit a frame. [Figure 7] FIG. 10 is a diagram illustrating another example of the flow of processing for determining whether or not to transmit a frame. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] (System Configuration) FIG. 1 shows an example of the configuration of a wireless communication system according to this embodiment (first embodiment). The wireless communication system includes, for example, an access point (AP 101) and a station (STA 102). The AP 101 and the STA 102 are communication devices capable of performing wireless communication in accordance with the IEEE 802.11 standard series. In this embodiment, when there is no need to distinguish between the AP 101 and the STA 102, they may be collectively referred to as communication devices. IEEE stands for Institute of Electrical and Electronics Engineers. FIG. 1 shows a configuration in which the STA 102 participates in a network 103 established by the AP 101. The network 103 may also be referred to as a Basic Service Set (BSS). Note that FIG. 1 shows a state in which a network 113 established by the AP 111 and in which the STA 112 participates exists near the network 103 established by the AP 101 and in which the STA 102 participates. The AP 111 and the STA 112 are communication devices capable of performing wireless communication in accordance with the IEEE 802.11 standard series, similar to the AP 101 and the STA 102. For the AP 101 and the STA 102, the network 103 is the BSS to which the respective devices connect, and hereinafter, this BSS will be referred to as the local BSS or simply as the BSS. On the other hand, for the AP 101 and the STA 102, the network 113 is a network that may cause interference with the local BSS, and may be referred to as an overlapping BSS (OBSS). Note that while FIG. 1 shows a state in which only one STA participates in each of the networks 103 and 113, it goes without saying that multiple STAs may participate in one network. Furthermore, one STA may participate in multiple networks.

[0011] In this embodiment, the AP 101 and the STA 102 are configured to be able to execute a communication method compliant with the IEEE 802.11bn standard. The IEEE 802.11bn standard is a successor to the IEEE 802.11be standard, targeting a maximum transmission speed of 46.08 Gbps (Giga bit per second). The IEEE 802.11bn standard is expected to include, as its main features, functions for realizing highly reliable communication, low latency communication, and improved throughput when communication traffic is congested. A wireless frame used in a communication method compliant with this standard may be called a UHR (Ultra High Reliability) PPDU. PPDU stands for PLCP Protocol Data Unit, and PLCP stands for Physical Layer Convergence Protocol. Note that names such as UHR and IEEE 802.11bn may be changed to different names when the standard is fully established. It should be noted that this specification and the claims appended hereto are applicable to communication devices using all successor standards to IEEE 802.11be. The communication device may also support at least one legacy standard that predates the IEEE 802.11bn standard. Examples of legacy standards include the IEEE 802.11a / b / g / n / ac / ax / be standards. The communication device may also support other communication standards such as Bluetooth (registered trademark), NFC, UWB, ZigBee, and MBOA. UWB stands for Ultra Wide Band, and MBOA stands for Multi-Band OFDM Alliance. NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, and the like. The communication device may also support communication standards such as wired LAN. The AP 101 may be, for example, a wireless LAN router or a personal computer (PC), but is not limited thereto. The AP 101 may be an information processing device such as a wireless chip capable of performing wireless communication conforming to the IEEE802.11bn standard or the like.The STA 102 may be, for example, but is not limited to, a camera, a tablet, a smartphone, a PC, a mobile phone, a video camera, a headset, etc. The STA 102 may be an information processing device such as a wireless chip capable of performing wireless communication in accordance with the IEEE802.11bn standard or the like.

[0012] A communication device may transmit and receive wireless signals using frequency bands such as the 2.4 GHz band, 3.6 GHz band, 5 GHz band, and 6 GHz band, as well as millimeter wave bands such as the 45 GHz band and the 60 GHz band. The frequency bands used by the communication device are not limited to these and may include, for example, the sub-1 GHz band. Furthermore, the communication device may communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by the communication device are not limited to these and may be bandwidths of 240 MHz or 4 MHz. The IEEE 802.11 standard series specifies a frequency channel using a 20 MHz bandwidth as the basic channel in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands. This standard also defines multiple available channels in each of the 2.4 GHz, 5 GHz, and 6 GHz bands. In this standard, communication devices can use a channel in combination with an adjacent channel. This use of a channel in combination with an adjacent channel can be called channel bonding. A bundle of channels formed by one or two or more adjacent channels can be called a communication link. For example, a link formed by two 20-MHz-bandwidth channels can use a 40-MHz bandwidth. The IEEE 802.11be standard is expected to specify 320 MHz as the maximum bandwidth available for a single link. Signals transmitted in this bandwidth can be continuous or discontinuous on the frequency axis. The AP 101 and STA 102 may be AP MLD (Multi-Link Device) and STA MLD, respectively, that support Multi-Link, which simultaneously establishes multiple links for communication.

[0013] When transmitting a signal using a link established with another communication device, a communication device performs carrier sensing to determine whether transmission is possible. Carrier sensing is an operation in which a communication device determines whether a signal is present on a channel that the communication device intends to use for transmission. For example, the communication device measures the strength of a signal received on a channel (received signal strength) and determines that a signal is present if the received signal strength exceeds a predetermined threshold (physical carrier sensing). The received signal strength may also be referred to as a Received Signal Strength Indicator (RSSI). The communication device may also determine the presence or absence of a signal based on information such as a Duration field included in a signal received on a channel (virtual carrier sensing). For example, the communication device stores the period indicated by the Duration field included in the received signal as a Network Allocation Vector (NAV) in the communication device. The communication device may treat the stored NAV as a period during which transmission of wireless frames from the communication device is prohibited. In this embodiment, the operation in which the communication device sets a period during which the communication device will not transmit based on information such as the Duration field of a received signal is referred to as setting a NAV. That is, the communication device determines that a signal is present on the channel until the NAV set for the channel expires. In this way, the communication device determines whether a signal is present on the channel based on the results of performing physical carrier sense and virtual carrier sense. If the communication device determines that a signal is present on the channel, it may determine that the channel is in a state where signal transmission is not possible. The channel state in this case may be called a busy state. On the other hand, a state in which no signal is detected on the channel by carrier sense and no NAV is set may be called an idle state. If the channel is in an idle state, the communication device may determine that a signal can be transmitted.

[0014] For example, when communicating using a link with a bandwidth of 160 MHz, a communication device may determine whether to transmit using only a first channel with a bandwidth of 20 MHz included in the link. This first channel may be called a Primary Channel (PCH). For example, the IEEE 802.11 series of standards describes that a communication device can start transmitting a signal if it determines that transmission is possible as a result of performing carrier sensing on the PCH for a predetermined period of time. The predetermined period is determined by an Interframe Space (IFS) defined for each access category that classifies the type of communication traffic, and a random number (backoff counter) randomly determined from a predetermined range. That is, if the communication device determines that the PCH is idle for this predetermined period of time, it acquires the right to transmit using that link. At this time, if a second channel other than the PCH is idle during the PIFS period immediately before the start of transmission, the communication device may perform channel bonding transmission using the idle channel and the PCH. PIFS stands for Priority IFS. Furthermore, when a communication device determines that it cannot transmit a signal as a result of performing carrier sensing on the PCH, even if other channels included in the same link are idle, it postpones the transmission of the signal without transmitting the signal only on the other channels. Each second channel other than the PCH that constitutes one link may also be called a secondary channel (SCH) or a non-primary channel (NPCH).

[0015] When a communication device receives a signal on a channel, if a signal is transmitted on another channel (e.g., an adjacent channel) located at a frequency close to the received channel, the received signal may not be properly received. For example, a communication device may be capable of simultaneously transmitting and receiving signals using different channels. If a communication device is receiving signals on a channel and then transmitting on an adjacent channel, the power of the transmitted signal may leak into the channel of the received signal, causing interference with the received signal. Generally, the power of the transmitted signal leaking out is much greater than the received power of the received signal, making it impossible to properly receive the signal. To avoid this situation, the IEEE 802.11 series of standards provides a mechanism to prevent other communication devices from transmitting signals to a communication device using a channel adjacent to the PCH while the communication device is transmitting a signal. That is, the PCH is provided as a channel commonly used between communication devices to determine whether or not to transmit, and it is specified that while one communication device is transmitting using the PCH, the other communication device shall not transmit, even if the other channel is idle. As a result, while a communication device is transmitting a signal and the PCH is in use, other communication devices will not transmit signals using channels adjacent to the PCH, preventing the communication device from receiving signals on the adjacent channels. This eliminates the problem of interference caused by power leakage between channels.

[0016] However, not using other idle channels (NPCHs) based on the PCH being busy can hinder efficient use of frequency resources across the link. Figure 2(A) shows an example of a time chart when STA 102 transmits data to AP 101. In Figure 2(A), STA 102 performs carrier sensing on the PCH, confirms that the PCH is idle, and then transmits data using the PCH with a 20 MHz bandwidth. In this case, even if seven NPCHs other than the PCH are idle, other communication devices are not permitted to communicate using the NPCHs. Figure 2(B) shows another example of a time chart when STA 102 transmits data to AP 101. In Figure 2(B), an example is shown in which the PCH is being used by another network (e.g., network 113 in Figure 1) located geographically close to STA 102 while STA 102 is performing carrier sensing on the PCH. In this case, the PCH is determined to be busy by carrier sensing by STA 102, and therefore STA 102 is not permitted to communicate with AP 101 using the NPCH, even if, for example, the seven NPCHs other than the PCH are idle. However, because AP 101 is not transmitting at this time, if STA 102 transmits to AP 101 using the NPCH, it is expected that AP 101 will be able to properly receive the signal transmitted by STA 102. In this way, if, for example, the PCH with a bandwidth of 20 MHz is used by another network, the remaining 140 MHz of idle NPCH will not be used, and frequency resources will not be used efficiently.

[0017] In view of the above circumstances, this embodiment provides a function for performing communication between communication devices using an NPCH included in the same link as the PCH, without using the PCH, when the PCH is being used by another communication device. As an example, when the PCH is busy, the communication device sets a Secondary Primary Channel (SPCH) to be used to acquire a transmission right for transmission using the NPCH. The SPCH is one or more channels among the NPCHs included in the same link as the PCH. Note that the name SPCH is just an example, and other names may be used. For example, the name PSCH (Primary Secondary Channel) may be used instead of the name SPCH as a channel with a high priority for determining whether or not transmission is possible among multiple secondary channels. Furthermore, the SPCH or the PSCH may be called by other names as long as they share the same meaning as the channel used to determine whether or not transmission using the NPCH is possible. When the communication device determines that the PCH is being used by another communication device, it subsequently determines whether or not transmission is possible on the SPCH. That is, the communication device performs the above-described carrier sense on the SPCH and determines that communication using the NPCH is possible based on confirmation that the SPCH is in an idle state. Then, when the communication device determines that transmission is possible on the SPCH, it performs transmission using one or more NPCHs including the SPCH. In this embodiment, a communication method in which transmission is performed using one or more channels including the SPCH without using a PCH is called NPCH access (Non-Primary Channel Access). Note that this communication method may be called by other names such as NPCA (Non-Primary Channel Access). Furthermore, the SPCH may also be called an NPCA Primary Channel. For example, this communication method may be called SCA (Secondary Channel Access). When a PCH is available, the communication device performs communication using a first communication method in which communication is performed over one communication link using the PCH and one or more NPCHs.On the other hand, the communication device is configured to be able to communicate using a second communication method (NPCH access) if certain further conditions (e.g., NPCH is not in use) are met, provided that PCH is not available.

[0018] NPCH access enables access using only the NPCH during a period when the PCH is busy. That is, for example, a communication device and a remote device communicating using the NPCH access resume communication using the PCH after the NPCH access period (i.e., the period during which the PCH is busy) has elapsed. Due to such state transitions, when the communication device and the remote device resume use of the PCH after performing a predetermined communication during the NPCH access period, a situation may arise in which the efficiency of the communication is actually reduced by performing the predetermined communication over the NPCH. For example, if a communication in which a communication device transmits a Request frame and a remote device transmits a Response frame is not completed within the NPCH access period, retransmission of the Request frame may be necessary. Similarly, if a series of communications including the transmission of a Request frame by the remote device and the transmission of a Response frame by the communication device are not completed within the NPCH access period, the series of communications may need to be repeated. Furthermore, even if the communication of the Request frame and the Response frame can be completed using the NPCH access, subsequent communications may not be possible. For example, suppose that a STA sends a Probe Request using the NPCH, the AP replies with a Probe Response frame on the NPCH, and then the AP terminates NPCH access and resumes use of the PCH. In this case, after receiving the Probe Response frame on the NPCH, the STA is unable to find the AP on the NPCH and is unable to continue the subsequent connection process. For example, even if the STA sends an Authentication frame or Association Request frame to the AP on the NPCH, the AP does not send an Authentication frame or Association Response frame on the NPCH. This can result in the STA being in an unnecessary communication standby state.Furthermore, even if the transmission and reception of an authentication frame or an association frame is completed during NPCH access, there is a possibility that the connection state cannot be maintained when the AP or STA subsequently resumes use of the PCH. That is, the connection settings established between the AP and the STA using the NPCH may not be usable after resuming communication using the PCH, or, for example, the STA may recognize the NPCH as a PCH, making subsequent communication impossible. A similar issue may also occur in communication of an action frame that requires a response, such as an Add Block Acknowledgment (ADDBA) Request frame. For example, if the AP resumes communication using the PCH at the time of transmitting the response frame after transmitting an action frame using the NPCH, it may be unable to receive the response frame. For other frames, if a frame is transmitted using the NPCH during NPCH access, and the transmission timing of the response frame for that frame is transmitted after the end of the NPCH access period, retransmission of the frame may be necessary. For example, assume that the AP transmits a beacon frame using the NPCH, then terminates NPCH access and resumes use of the PCH. In this case, after receiving a Beacon frame in the NPCH, the STA will be unable to find the AP in the NPCH and will be unable to continue the subsequent connection process. For example, even if the STA transmits an Authentication frame or Association Request frame to the AP in the NPCH, the AP will not transmit an Authentication frame or Association Response frame in the NPCH. This may result in the STA being in an unnecessary communication standby state. Furthermore, even if the transmission and reception of an Authentication frame or Association frame is completed during NPCH access, there is a possibility that the connection state will not be maintained when the AP or STA resumes use of the PCH thereafter.

[0019] In this embodiment, in consideration of the above circumstances, when a frame to be transmitted occurs during a period in which NPCH access can be performed in a communication device, the type of the frame determines whether or not the frame should be transmitted.

[0020] For example, the communication device may stop transmitting a radio frame if a radio frame to be transmitted during an NPCH access period is a predetermined frame that requires a response from a remote device. This can prevent communication failures caused by not receiving a response in the NPCH when the NPCH access period ends after the transmission of a predetermined frame, for example. Furthermore, the communication device may stop transmitting a radio frame if a radio frame to be transmitted during an NPCH access period is a response frame transmitted in response to a predetermined frame from a remote device. For example, if the response frame in response to the predetermined frame is a frame that requires the remote device to transmit a further radio frame, the communication device may stop transmitting the response frame. Note that, for example, a frame that does not require the remote device to transmit a further radio frame, such as an acknowledgment (ACK or Block ACK) for a normal data frame, may be determined to be transmitted during the NPCH access period.

[0021] Furthermore, if a wireless frame to be transmitted during the NPCH access period is a management frame related to connection processing, the communication device may suspend transmission of the wireless frame. For example, the STA 102 does not transmit wireless frames such as a Probe Request or an Association Request to the AP 101 during the NPCH access period. Furthermore, when the AP 101 receives a Probe Request or an Association Request from the STA 102, it does not return a Probe Response or an Association Response to the STA 102. Similarly, the communication device does not transmit Request / Response frames such as Reassociation and Authentication during the NPCH access period. In other words, the STA 102 does not transmit any Request frames, and the AP 101 does not transmit any Response frames during the NPCH access period. Furthermore, the AP 101 and the STA 102 may not transmit frames such as Deauthentication and Disassociation, or acknowledgements (ACKs) for those frames, during the NPCH access period. Similarly, the AP 101 may also prevent the transmission of Beacon frames during the NPCH access period. It is possible to prevent all or some of these Management frames from being transmitted. This prevents situations such as a process failure due to the end of the NPCH access period during the connection process, or the need for additional settings for communication using the PCH even after the process is completed. The communication device may also prevent the transmission of specific Action frames that require a response, such as an ADDBA Request, an RM Request, or an FT Request, during the NPCH access period. The communication device may also prevent the transmission of response frames (ADDBA Response, RM Response, FT Response) to the specific Action frames during the NPCH access period.Note that, when the communication device receives the above-described predetermined Action frame, if transmitting the response frame completes a series of settings, the communication device may transmit the response frame even during the NPCH access period. That is, if the wireless frame transmitted by the communication device does not trigger the transmission of a wireless frame from the other device, the communication device may determine to transmit the wireless frame to be transmitted during the NPCH access period, even if the wireless frame is an Action frame. That is, the communication device may determine not to transmit frames in control communication that involve the reception of other frames from the other device (Management frames and Action frames) during the NPCH access period. Note that the concept of "involving reception" here means that other frames from the other device are expected to arrive, but does not necessarily mean that they are actually received. For example, if the other device does not successfully receive the predetermined frame transmitted by the communication device, the communication device may not receive a response to the predetermined frame. However, the concept of "involving reception of a frame from the other device" also includes such a case. Note that, for example, the communication device may determine to transmit the frame to be transmitted if the control communication ends after transmitting the frame to be transmitted (if there is no subsequent reply). However, if there is a possibility that the settings made through the control communication will become unusable after the resumption of communication using the PCH, the communication device may decide not to transmit the frame even if the control communication would be completed by transmitting the frame. For example, the communication device may decide not to transmit a frame such as an Authentication Response during NPCH access. This prevents communication (control processing) from being left uncompleted or prevents the configuration processing itself during NPCH access, while making effective use of NPCH access and improving the efficiency of the entire system.

[0022] Furthermore, the communication device may predetermine frames to be transmitted during the NPCH access period. In one example, the communication device may be pre-configured so that frames to be transmitted during the NPCH access period are limited to data frames requiring low latency. As a result, when the PCH is busy, data frames requiring low latency are transmitted on the NPCH, thereby improving delay characteristics. On the other hand, for example, frames other than data frames requiring low latency (e.g., wireless frames for the connection process described above and Action frames requiring a response) may not be transmitted during the NPCH access period. As a result, similar to the above example, the NPCH access can be effectively utilized while preventing communication (control process) from being incomplete. In one example, a data frame whose transmission priority indicated by a Traffic Identifier (TID) is set to a predetermined value is treated as a data frame requiring low latency. In one example, an access category is indicated by two bits of the TID. Then, for example, a data frame to which an access category such as AC_VO or AC_VI is assigned according to the value thereof can be treated as a data frame to be transmitted during the NPCH access period. In the above example, data frames containing audio data or video (streaming) data are defined as data frames to be transmitted during NPCH access by TID (or AC), but this is not limiting. That is, frames to be transmitted during NPCH access may be defined without using TID or AC. For example, frames containing data used for strict timing control for robot control, or data that affects the user experience for print jobs, photo sharing, etc., may be transmitted during NPCH access as frames requiring low latency. In this case, whether or not a frame to be transmitted contains data requiring low latency may be determined, for example, depending on the type of application. Furthermore, an application that outputs data may output, together with the data, information indicating whether or not the data requires low latency transmission.In these cases, the communication device may determine whether to transmit a data frame containing data generated during an NPCH access period based on which application the data originated from or on information provided by the application. Note that these are merely examples, and it may also be determined whether a data frame contains data requiring low latency based on other information or conditions. Furthermore, among data frames requiring low latency, data frames that do not require an ACK (acknowledgment) may be transmitted during an NPCH access period, while data frames that require an ACK may not be transmitted. Furthermore, the type of data frame transmitted during an NPCH access period may be specified arbitrarily, without being limited to data requiring low latency.

[0023] The following describes in detail an example of the configuration of a communication device that performs such processing and the flow of the processing. Note that the following description focuses on communication between AP 101 and STA 102, but the same discussion can also be applied to communication between AP 111 and STA 112, or communication between multiple STAs, for example.

[0024] (Device configuration) 3 shows an example of the hardware configuration of the communication device (AP 101 and STA 102) of this embodiment. As an example of the hardware configuration, the communication device has, for example, a storage unit 301, a control unit 302, a function unit 303, an input unit 304, an output unit 305, a communication unit 306, and an antenna 307. Note that these are just examples, and the communication device may have further components not shown in FIG. 3, or some or all of the components shown in FIG. 3 may be replaced with other components having similar functions.

[0025] The storage unit 301 is configured to include one or more memories such as a ROM or a RAM. The storage unit 301 stores various information such as computer programs for performing various operations described below and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. The storage unit 301 may be configured to include storage media such as a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, or a DVD, in addition to memories such as a ROM or a RAM. The storage unit 301 may also be configured to include storage media such as a plurality of memories.

[0026] The control unit 302 is configured to include one or more processors, such as a CPU or an MPU. CPU stands for Central Processing Unit, and MPU stands for Micro Processing Unit. The control unit 302 controls the entire communication device by executing a computer program stored in the storage unit 301. The control unit 302 may control the entire device in cooperation with an operating system and the computer program stored in the storage unit 301. The control unit 302 also generates data and signals (radio frames) to be transmitted in communication with other communication devices. The control unit 302 may also include multiple processors, such as multi-core processors, and the entire communication device may be controlled by the multiple processors.

[0027] Furthermore, the control unit 302 controls the functional unit 303 to perform predetermined processes such as wireless communication, image capture, printing, and projection. The functional unit 303 is configured to include hardware that enables the communication device to perform predetermined processes. If the communication device is a printer, the functional unit 303 is a printing device that prints image data acquired via the communication unit 306, for example. If the communication device is a scanner, the functional unit 303 is a reading device that outputs image data generated by scanning to the outside, for example, via the communication unit 306. If the communication device is a camera, the functional unit 303 is configured to include an image sensor and a lens, and outputs image data captured by the camera to the outside, for example, via the communication unit 306.

[0028] The input unit 304 includes, for example, a touch panel, hard keys, buttons, etc., and accepts various operations from the user. The output unit 305 includes, for example, a display, a speaker, etc., and provides various outputs to the user. Here, the output by the output unit 305 may be a screen display output on a display or an audio output from a speaker. The output unit 305 may also include a vibrator and may output information by vibration output. Note that both the input unit 304 and the output unit 305 may be implemented by a single module, such as a touch panel display. The input unit 304 and the output unit 305 may be built into the communication device, or may be implemented by an external input / output device. In this case, the communication device has an input / output interface for connecting to the input / output device.

[0029] The communication unit 306 executes control for wireless communication compliant with the IEEE 802.11bn standard. The communication unit 306 may also control wireless communication compliant with other IEEE 802.11 standard series, such as legacy standards, in addition to the IEEE 802.11bn standard, and wired communication, such as a wired LAN. The communication unit 306 controls the antenna 307 to transmit and receive signals for wireless communication generated by the control unit 302. For example, the communication device communicates data, such as image data, document data, and video data, with a partner device via the communication unit 306. If the communication device supports standards such as the NFC standard and Bluetooth in addition to the IEEE 802.11bn standard, the communication unit 306 may also control wireless communication compliant with these communication standards. If the communication device is capable of wireless communication compliant with multiple communication standards, separate communication units and antennas compatible with those communication standards may be provided.

[0030] The antenna 307 is, for example, an antenna capable of detecting and emitting radio waves in the 2.4 GHz band, the 5 GHz band, and the 6 GHz band. The antenna 307 may be configured to be capable of communication in the same frequency band. In this case, the antenna 307 may be, for example, a multi-band antenna capable of communication in multiple frequency bands. While FIG. 3 illustrates an example in which the communication device has two antennas, one antenna or three or more antennas may be used. If the communication device has multiple antennas, it may have a communication unit 306 corresponding to each antenna. The antenna 307 may be provided separately from the communication unit 306, or may be configured together with the communication unit 306 as a single module. The communication device may also be configured to be capable of performing carrier sensing of multiple SPCHs in parallel. In this case, the communication device may have the number of communication units 306 and antennas 307 required to perform carrier sensing of the multiple SPCHs in parallel.

[0031] 4 shows an example of the functional configuration of the communication device. The communication device is configured to include, as its functional configuration, a frame control unit 401, a NAV detection unit 402, a wireless communication control unit 403, an NPCH access control unit 404, an NPCH frame transmission determination unit 405, and a frame analysis unit 406. These functional configurations can be realized, for example, by executing programs stored in one or more memories that constitute the storage unit 301 by one or more processors that constitute the control unit 302. Note that some or all of these functional configurations may be implemented by dedicated hardware.

[0032] The frame control unit 401 generates a signal (frame) to be transmitted to a remote device (for example, the STA 102 when the communication device is the AP 101, or the AP 101 when the communication device is the STA 102). The frame control unit 401 generates, for example, a management frame used for communication control in addition to a data frame containing user data to be transmitted to the remote device. The user data included in the data frame is classified, for example, by an access category (AC), and when transmitting the data frame, QoS (Quality of Service) control is performed according to the classification. Currently, four ACs are defined: AC_VO (voice), AC_VI (video), AC_BE (best effort), and AC_BK (background). For example, data such as AC_VO and AC_VI indicate that low latency is required. The management frame includes a probe request / probe response for searching for a remote device. The management frame also includes an association request / association response for establishing a connection, and a disassociation for disconnecting the connection. The Management frame also includes an Authentication Request / Authentication Response for authentication. The Management frame also includes a Deauthentication for deauthentication. The frame control unit 401 can generate an Ack for the Deauthentication frame or the Disassociation frame. The frame control unit 401 also generates Action frames such as an ADDBA frame, a Radio Measurement (RM) frame, and a Fast BSS Transition (FT) frame.

[0033] The NAV detection unit 402 sets the NAV of the PCH or SPCH based on the Duration value extracted from the received frame by the frame analysis unit 406 (described later). For example, the NAV detection unit 402 sets the NAV of the PCH based on the Duration value included in the radio frame received in the PCH. The NAV detection unit 402 also sets the NAV of the SPCH based on the radio frame received in the SPCH during the period when the NPCH access is performed.

[0034] The wireless communication control unit 403 performs a transmission process for each frame generated by the frame control unit 401. The wireless communication control unit 403 also transfers frames received via the antenna 307 to the frame analysis unit 406. For example, the wireless communication control unit 403 can transmit or receive data frames using either the first or second communication method described above. As an example, when a wireless frame to be transmitted exists, the wireless communication control unit 403 performs carrier sensing of the PCH. Then, when the PCH is idle, the wireless communication control unit 403 transmits the wireless frame using the PCH and, if necessary, using one or more NPCHs. On the other hand, when the PCH is busy, the wireless communication control unit 403 determines whether communication via NPCH access is possible. For example, the wireless communication control unit 403 performs carrier sensing in the SPCH that is preset for NPCH access. Then, when the wireless communication control unit 403 does not detect a wireless frame in the SPCH and the NAV detection unit 402 does not set a NAV for the SPCH, the wireless communication control unit 403 transmits the data frame using one or more NPCHs including the SPCH.

[0035] The NPCH access control unit 404 performs settings for performing NPCH access and controls for communication via NPCH access. For example, when a link is established with a counterpart device, the NPCH access control unit 404 may exchange setting information necessary for performing NPCH access and perform control based on the setting information. The NPCH access control unit 404 may also perform setting and control using information determined in advance by a standard, for example. The NPCH access control unit 404 may also store some setting information in advance and exchange another part of the setting information with the counterpart device when a link is established with the counterpart device. For example, after the setting for NPCH access has been established, the NPCH access control unit 404 may exchange predetermined radio frames with the counterpart device to update at least a part of the setting for NPCH access.

[0036] The NPCH frame transmission determination unit 405 determines whether or not to transmit a frame based on control information by the NPCH access control unit 404 and the contents of the frame generated in the frame control unit 401. For example, when NPCH access is being executed by the NPCH access control unit 404, the NPCH frame transmission determination unit 405 determines whether or not to transmit the frame based on the type of frame to be transmitted that is generated by the frame control unit 401. For example, when the frame to be transmitted is a Management frame related to a change in the configuration of the network, the NPCH frame transmission determination unit 405 determines not to transmit (cancel) the frame. Furthermore, when the frame to be transmitted is a predetermined frame such as an Action frame that requires a response from the other device, the NPCH frame transmission determination unit 405 may determine not to transmit the frame. Furthermore, when the NPCH frame transmission determination unit 405 receives the above-mentioned predetermined frame from the other device, it may not transmit a response to the predetermined frame. The NPCH frame transmission determination unit 405 may determine that only frames requiring low latency, such as AC_VI and AC_VO, are to be transmitted during the NPCH access period, and that other frames are not to be transmitted. The NPCH frame transmission determination unit 405 notifies the radio communication control unit 403 of the determination result as to whether or not to transmit the frame. When the radio communication control unit 403 is notified of the suspension of frame transmission as a result of the determination, it performs control so that the frame is not transmitted during the NPCH access period. Note that when the radio communication control unit 403 is notified of the suspension of frame transmission, it may discard the frame, or may hold the frame until communication using the PCH is resumed and transmit it after the resumption.

[0037] The frame analysis unit 406 analyzes a frame received from a remote device and acquires information and user data required for communication. The frame analysis unit 406, for example, acquires a Duration value from the received frame and notifies the NAV detection unit 402. The frame analysis unit 406 may analyze a frame generated by the frame control unit 401, analyze the type of the frame, and notify the NPCH frame transmission determination unit 405. In this case, the NPCH frame transmission determination unit 405 may acquire information about the content of the frame generated in the frame control unit 401 from the frame analysis unit 406 instead of the frame control unit 401, and make the above-mentioned determination. The frame analysis unit 406 does not have to analyze the frame to be transmitted, and the frame control unit 401 may notify the NPCH frame transmission determination unit 405 of information about the frame to be transmitted.

[0038] (Processing flow) Next, an example of the flow of processing executed between the AP 101 and the STA 102 will be described. In the following, a process will be described in which, when a wireless frame to be transmitted occurs, the AP 101 determines whether to transmit the wireless frame based on whether the period is an NPCH access period and the type of the frame. Note that this is just an example, and similar processing may also be performed in the STA 102.

[0039] 5 shows an example of the flow of processing in which, when a frame to be transmitted is generated in the AP 101, the AP 101 determines whether or not to transmit the frame. When a frame to be transmitted is generated (S501), the AP 101 determines whether or not it is currently in an NPCH access period (S502). If the AP 101 determines that it is not currently in an NPCH access period (NO in S502), it decides to transmit the generated frame (S503). On the other hand, if the AP 101 is currently in an NPCH access period, it determines whether or not the generated frame is of a type that should be transmitted during an NPCH access period (S504). If the generated frame is of a type that should be transmitted during an NPCH access period (YES in S504), the AP 101 decides to transmit the frame (S503). On the other hand, if the generated frame is not of a type that should be transmitted during an NPCH access period (NO in S504), the AP 101 decides not to transmit the frame (S505).

[0040] Next, an example of the flow of the determination process in S504 (the process of determining whether the generated frame should be transmitted during the NPCH access period) will be described with reference to FIG. 6. The AP 101 determines whether the generated frame is a management frame related to a change in the network configuration (S601). Management frames related to a change in the network configuration may include probe, association, and authentication requests / responses. Management frames also include deauthentication frames and disassociation frames. If the deauthentication frame or disassociation frame is successfully received, an acknowledgment (ACK) is transmitted. The deauthentication frame or disassociation frame may be configured to be retransmitted if an ACK is not received. If the generated frame is a management frame related to a change in the network configuration (YES in S601), the AP determines that the frame is a frame that should not be transmitted during the NPCH access period (S604). On the other hand, if the generated frame is not a management frame related to a change in the network configuration (NO in S601), it is determined whether the frame is an action frame that requires a response (S602). Action frames that require a response include, for example, an ADDBA request, an RM request, and an FT request. If the generated frame is an action frame that requires a response (YES in S602), AP 101 determines that the frame is a frame that should not be transmitted within the NPCH access period (S604). On the other hand, if the generated frame is not an action frame that requires a response (NO in S602), AP 101 determines that the frame is a frame that should be transmitted within the NPCH access period (S603).

[0041] 6 is an example, and may be changed according to, for example, a network policy. For example, if it is determined in S601 that the generated frame is not a management frame related to a network configuration change, it may be determined that the frame should be transmitted during the NPCH access period without performing the determination in S602. Similarly, it may be determined whether or not the generated frame should be transmitted during the NPCH access period by determining only whether or not the generated frame is a predetermined frame (for example, an action frame) that requires a response without performing the determination in S601.

[0042] FIG. 7 shows another example of the flow of the determination process in S504 (determination process of whether a generated frame should be transmitted during an NPCH access period). The AP 101 determines whether QoS settings, such as access category and TID settings, have been made for the data included in the generated frame (S701). Note that instead of the access category and TID, it may also be determined whether any other information capable of identifying the attributes of the data to be transmitted (low latency, high reliability, large capacity, etc.) is associated with the generated frame. That is, in S701, the determination of whether attributes related to user data have been set may be made in any format. If QoS settings have not been made for the data included in the generated frame (NO in S701), the AP 101 may determine not to transmit the frame during an NPCH access period (S704). For example, it is assumed that an access category is not set for the above-mentioned Management frame or Action frame. Therefore, it may be determined that such frames will not be transmitted during an NPCH access period because QoS settings have not been made for them.

[0043] On the other hand, if QoS is set for the data contained in the generated frame (YES in S701), the AP 101 determines whether the frame is a frame for which low latency is required based on the QoS setting (S702). If the AP 101 determines that a frame for which low latency is required has occurred (YES in S702), it decides to transmit the frame during the NPCH access period (S703). On the other hand, if the AP 101 determines that the generated frame does not require low latency (NO in S702), it may decide not to transmit the frame during the NPCH access period (S704).

[0044] Note that the processing flow in FIG. 7 is merely an example and may be changed according to network policies, etc. For example, only one of the determinations in S701 and S702 may be performed. Furthermore, the example in FIG. 7 illustrates an example in which only frames requiring low latency are transmitted, but this is not limiting. For example, frames requiring highly reliable communication may not be transmitted during NPCH access, and only frames not requiring highly reliable communication may be transmitted during NPCH access. Conversely, only frames requiring highly reliable communication may be transmitted during NPCH access. Furthermore, for example, frames containing large amounts of data (e.g., data sizes exceeding a predetermined value) may not be transmitted during NPCH access, and only frames containing relatively small amounts of data may be transmitted during NPCH access. Conversely, only frames containing large amounts of data may be transmitted during NPCH access. In this way, whether or not a frame should be transmitted during NPCH access may be determined according to various attributes of the data contained in the frame.

[0045] As described above, in this embodiment, whether or not to transmit a frame generated in a situation where the AP 101 and the STA 102 can perform communication via NPCH access is determined based on the frame's type. For example, if a management frame related to a network configuration change is generated as a frame to be transmitted, the frame can be prevented from being transmitted during the NPCH access period, thereby preventing connection processing and the like from ending in failure. Furthermore, if an action frame requiring a response is generated as a frame to be transmitted, the frame can be prevented from being transmitted during the NPCH access period, thereby preventing communication failure due to a failure to receive a response. Furthermore, by transmitting only data frames requiring low latency during the NPCH access period, the data frames can be transmitted with sufficiently good latency characteristics (low latency), while preventing communication failures such as the above-mentioned control frames. These features prevent waste of frequency resources and power consumption, enabling efficient communication.

[0046] The type of radio frame to be transmitted during the NPCH access period may be dynamically set. In this case, for example, the AP 101 may transmit information about the frame type to the currently connected STA using, for example, an Action frame. This notification may be transmitted, for example, during a period when the PCH is available. The AP 101 may also notify the information about the frame type in, for example, a Beacon frame that is periodically transmitted during a period when the PCH is available (a period when NPCH access is not performed). The STA may transmit only frames of the type indicated by the notification during the NPCH access period. The notification may also notify the information about the type of frames that should not be transmitted.

[0047] (Second embodiment) In another embodiment, when an AP receives a frame from a STA during an NPCH access period, if the STA that transmitted the frame is capable of NPCH access and has completed association processing, the AP may transmit a response frame; otherwise, the AP may discard the received frame and not transmit the response frame. Whether NPCH access is possible can be determined by the AP, for example, based on the capability information included in the association request frame transmitted by the STA during association or the capability information included in the probe request frame transmitted by the STA. Furthermore, the AP may transmit a response frame if the STA that transmitted the frame received during the NPCH access period is a STA that has completed association processing, or may discard the received frame and not transmit the response frame if the STA has not completed association processing. In this way, by the AP not responding to a frame received from a STA that has not completed association processing in the NPCH, it is possible to prevent the STA's connection processing from failing or to prevent unnecessary frame exchange. This prevents waste of frequency resources and power consumption, enabling efficient communication. Naturally, it is also possible to operate the AP by appropriately combining the control of the first embodiment and the control of the second embodiment. In this case, it is also possible to operate the AP by combining only some of the controls. For example, the AP can perform control by combining some of the controls described in the second embodiment while similarly performing control to prevent Beacon frames from being transmitted on the SPCH during NPCH access.

[0048] (Third embodiment) In another embodiment, frame exchange during the NPCH access period may be initiated when the AP or STA transmits or receives a frame called an Initial Control Frame (ICF) for NPCH access. In this case, the AP or STA may transmit a response frame if it receives a frame from the communication device that sent the ICF or from the communication device that is the destination of the ICF during the NPCH access period; otherwise, it may discard the received frame and not return a response frame. That is, a configuration may be used in which a constraint is imposed so that ICFs must be exchanged between devices when attempting to transmit or receive actual data or frames via one or more channels including at least the SPCH during the NPCH access period. In this way, in this embodiment, it is possible to prevent unintended failures in processing with a partner device and unnecessary frame exchanges due to a communication device not responding to a frame received from an unintended partner device in the NPCH, and to prevent unnecessary frame exchanges. As a specific example, it is possible to prevent STA connection processing from failing and unnecessary frame exchanges due to an AP not responding to a frame received from an unintended partner device in the NPCH. This prevents waste of frequency resources and power consumption, and enables efficient communication. The control described in the third embodiment can also be executed in appropriate combination with the control of the first and second embodiments. The SPCH may also be called the NPCA Primary Channel.

[0049] (Fourth embodiment) An embodiment as a further modification of the third embodiment will be described. As in the third embodiment, the AP is controlled not to respond to management frames with a broadcast destination specified on the SPCH (e.g., a Probe Request frame with a broadcast address specified) during the NPCH access period. On the other hand, even when an ICF is not received on the SPCH during the NPCH access period, the AP can be configured to respond to management frames with the AP's MAC address specified as a unicast address. For example, the AP may be controlled to respond with a Probe Response frame, which is a response frame, to a Probe Request frame with the AP's MAC address explicitly specified. Note that the hardware and software configurations of the second to fourth embodiments are similar to those of the first embodiment, and therefore their explanations are omitted. Note that a further modification is possible in which a response frame is transmitted only when a management frame such as a Probe Request frame contains Capability information indicating that the IEEE 802.11bn standard is supported. In other words, if the AP receives a management frame via the SPCH during the NPCH access period that is clearly transmitted from an STA that complies with the IEEE 802.11be standard or earlier, the AP can be controlled not to respond to the management frame. On the other hand, if the AP receives a management frame during an NPCH access period via the SPCH that is clearly transmitted from a STA that supports IEEE 802.11bn or later, the AP can control the AP to respond to the management frame. For example, if a frame received from a STA includes a UHR Capabilities Element, the AP determines whether the STA supports the IEEE 802.11bn standard. Then, depending on the determination result, the AP can determine whether or not to respond to the frame. When this fourth embodiment is applied to an AP, the control described in the second embodiment may be configured not to be combined.It should be noted that it is also possible to apply some or all of the controls of the first embodiment in any combination to the fourth embodiment.

[0050] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0051] (Summary of the embodiment) At least some of the above-described embodiments can be summarized as follows. (Item 1) A communication device that performs communication in accordance with the IEEE 802.11 standard series, a communication means for performing communication using either a first communication method using at least the first channel in one communication link that is composed of a first channel used to acquire a transmission right and one or more second channels different from the first channel, or a second communication method using one or more of the second channels without using the first channel during a period when the first channel cannot be used; the communication means determines not to transmit a frame to be transmitted during the period when the frame to be transmitted is a predetermined frame in control communication involving reception of another frame from another communication device; A communication device comprising: (Item 2) 2. The communication device according to item 1, wherein the predetermined frame includes a management frame related to a change in network configuration. (Item 3) the communication device is a station; 3. The communication device according to item 2, wherein the management frame includes a probe request, an association request, a reassociation request, and an authentication request. (Item 4) the communication device is an access point; 3. The communication device according to item 2, wherein the management frame includes a probe response, an association response, a reassociation response, and an authentication response. (Item 5) 5. The communication device according to any one of items 1 to 4, wherein the predetermined frame includes an Action frame that requires a response from the other communication device. (Item 6) The communication device described in any one of items 1 to 5, characterized in that the communication means further determines not to transmit the frame to be transmitted during the period if QoS (Quality of Service) is not set for the data to be transmitted by the frame to be transmitted. (Item 7) 7. The communication device according to any one of items 1 to 6, wherein the communication means determines to transmit the frame to be transmitted during the period if the frame to be transmitted is a frame containing data that requires low latency. (Item 8) Item 8. The communication device according to item 7, characterized in that, when the access category of the frame to be transmitted is set to AC_VI or AC_VO, the communication means determines to transmit the frame to be transmitted during the period as a frame containing data requiring low latency. (Item 9) Item 7. The communication device according to item 7, wherein the communication means determines to transmit the frame to be transmitted during the period as a frame containing data requiring low latency when the data contained in the frame to be transmitted is data output from a specified application. (Item 10) 3. The communication device according to item 2, wherein the Management frame includes Deauthentication and Disassociation. (Item 11) A control method executed by a communication device that performs communication in accordance with the IEEE 802.11 standard series, comprising: the communication device is configured to perform communication in one communication link consisting of a first channel used to acquire a transmission right and one or more second channels different from the first channel, using either a first communication method using at least the first channel, or a second communication method using one or more of the second channels without using the first channel during a period when the first channel cannot be used; the control method includes determining, for a frame to be transmitted, not to transmit the frame to be transmitted during the period when the frame to be transmitted is a predetermined frame in control communication involving reception of another frame from another communication device; A control method comprising: (Item 12) A program for causing a computer to function as each of the means possessed by the communication device according to any one of items 1 to 10.

[0052] The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0053] 101: AP, 102: STA, 103: Network

Claims

1. A communication device that performs communication in accordance with the IEEE 802.11 standard series, a communication means for performing communication using either a first communication method using at least the first channel, or a second communication method using one or more of the second channels without using the first channel during a period when the first channel cannot be used, in one communication link consisting of a first channel used to acquire a transmission right and one or more second channels different from the first channel; the communication means determines not to transmit a frame to be transmitted during the period when the frame to be transmitted is a predetermined frame in control communication involving reception of another frame from another communication device; A communication device comprising:

2. 2. The communication device according to claim 1, wherein the predetermined frame includes a management frame related to a change in network configuration.

3. the communication device is a station; 3. The communication device according to claim 2, wherein the management frame includes a probe request, an association request, a reassociation request, and an authentication request.

4. the communication device is an access point; 3. The communication device according to claim 2, wherein the management frame includes a probe response, an association response, a reassociation response, and an authentication response.

5. 2. The communication device according to claim 1, wherein the predetermined frame includes an Action frame that requires a response from the other communication device.

6. 2. The communication device according to claim 1, wherein the communication means further determines not to transmit the frame to be transmitted during the period if a QoS (Quality of Service) is not set for the frame to be transmitted with respect to data to be transmitted by the frame.

7. 2. The communication device according to claim 1, wherein the communication means determines to transmit the frame to be transmitted during the period if the frame to be transmitted is a frame containing data that requires low delay.

8. The communication device according to claim 7, characterized in that, when the access category of the frame to be transmitted is set to AC_VI or AC_VO, the communication means determines to transmit the frame to be transmitted during the period as a frame containing data requiring low latency.

9. The communication device according to claim 7, characterized in that, when the data contained in the frame to be transmitted is data output from a specified application, the communication means determines to transmit the frame to be transmitted during the period as a frame containing data requiring low latency.

10. The communication device according to claim 2 , wherein the Management frame includes a Deauthentication frame and a Disassociation frame.

11. A control method executed by a communication device that performs communication in accordance with the IEEE 802.11 standard series, comprising: the communication device is configured to perform communication in one communication link consisting of a first channel used to acquire a transmission right and one or more second channels different from the first channel, using either a first communication method using at least the first channel, or a second communication method using one or more of the second channels without using the first channel during a period when the first channel cannot be used; the control method includes determining, for a frame to be transmitted, not to transmit the frame to be transmitted during the period when the frame to be transmitted is a predetermined frame in control communication involving reception of another frame from another communication device; A control method comprising:

12. A program for causing a computer to function as each of the means included in the communication device according to any one of claims 1 to 10.

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