Communication device, control method, and program

Abstract

An apparatus and method are provided that enable efficient operation of a communication device in a communication system that uses a communication link made up of multiple channels. [Solution] In a wireless communication system, a communication device that communicates with one or more other communication devices using wireless frames that comply with the IEEE802.11 standard is configured to be able to communicate by bonding a first channel and one or more second channels, and communicates using multiple communication methods including a first communication method that acquires the right to transmit using the first channel and communicates, and a second communication method that acquires the right to transmit using a third channel included in the second channel when the first channel cannot be used and communicates using at least the third channel, and enables or disables communication using the second communication method in the communication device based on whether other communication devices connected to the communication device are in a state where they can communicate using the second communication method.

Description

[Technical Field]

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

[0002] In recent years, the increasing volume of data being transmitted 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 main WLAN communication standard. The IEEE 802.11 standard 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 candidate technologies 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 techniques that enable efficient operation of communication devices in communication systems that use communication links made up 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 with one or more other communication devices using wireless frames that comply with at least one standard included in the IEEE 802.11 standard series, and includes a communication means for communicating using multiple communication methods, including a first communication method configured to enable communication by bonding a first channel with one or more second channels different from the first channel, the first communication method acquiring a transmission right using the first channel and communicating, and a second communication method acquiring a transmission right using a third channel included in the second channel when the first channel cannot be used and communicating using at least the third channel; an acquisition means for acquiring specific information from each of the other communication devices connected to the communication device, used to determine whether the other communication devices are in a state where they can communicate using the second communication method; and an acquisition means for enabling or disabling communication using the second communication method in the communication device based on whether the other communication devices connected to the communication device are in a state where they can communicate using the second communication method. [Effects of the Invention]

[0007] The present invention allows for efficient operation of a communication device 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 when a communication device enables an NPCH access function of the device itself. [Figure 6] FIG. 10 is a diagram illustrating an example of a processing flow when a communication device enables an NPCH access function of the device itself. [Figure 7] FIG. 10 is a diagram illustrating an example of a processing flow when a communication device enables an NPCH access function of the device itself. [Figure 8] FIG. 10 is a diagram illustrating an example of a processing flow when a communication device disables an NPCH access function of the device itself. [Figure 9] FIG. 10 is a diagram illustrating an example of a processing flow executed when a communication device communicates data. [Figure 10] 10 is a diagram illustrating an example of a format used when a communication device notifies information indicating whether or not it is in a state where it can perform NPCH access. FIG. [Figure 11] FIG. 10 is a diagram illustrating an example of a sequence executed between an AP and a STA. [Figure 12] FIG. 10 is a diagram illustrating an example of a sequence executed between an AP and a STA. [Figure 13] FIG. 10 is a diagram illustrating an example of a sequence executed between an AP and a STA. [Figure 14] FIG. 10 is a diagram illustrating an example of a sequence executed between an AP and a STA. [Figure 15] FIG. 10 is a diagram illustrating an example of a sequence executed between an AP and a STA. [Figure 16] FIG. 10 is a diagram illustrating an example of a sequence executed between an AP and a STA. 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. The wireless communication system includes, for example, an access point (AP) 101 and stations (STAs) 102 to 104. The AP 101 and the STAs 102 to 104 are communication devices capable of performing wireless communication in accordance with the IEEE 802.11 standard series. IEEE is an abbreviation for Institute of Electrical and Electronics Engineers. FIG. 1 shows a configuration in which the STAs 102 to 104 participate in a network 10 established by the AP 101. The network 10 may also be referred to as a Basic Service Set (BSS). The network 10 in FIG. 1 shows a configuration in which one AP 101 and three STAs exist, but there may be, for example, multiple APs and one, two, or four or more STAs. In this case, each STA may be connected to one AP, or one STA may be connected to multiple APs. Note that in FIG. 1, a network 11 consisting of an AP 111 and STAs 112 exists near the network 10. The AP 111 and the STA 112 are communication devices capable of performing wireless communication in accordance with the IEEE 802.11 series standard, similar to the AP 101 and the STA 102 to STA 104. For the AP 101 and the STA 102 to STA 104, the network 10 is a BSS to which the devices connect, and may be referred to as their own BSS. On the other hand, for the AP 101 and the STA 102 to STA 104, the network 11 is a network that may cause interference with the own BSS, and may be referred to as an overlapping BSS (OBSS). In this embodiment, the AP 101, the AP 111, the STA 102 to STA 104, and the STA 112 may be collectively referred to as the communication device 100. The following description will be given of the AP 101 and the STA 102 to STA 104, but the same description may also be applied to the AP 111 and the STA 112.

[0011] In this embodiment, the communication device 100 is configured to be able to execute a communication method conforming to the IEEE 802.11bn standard. The IEEE 802.11bn standard is a successor to the IEEE 802.11be standard, which targets a maximum transmission speed of 46.08 Gbps (Giga bit per second). The main features of the IEEE 802.11bn standard are that it has functions that realize highly reliable communication, low latency communication, and improved throughput when communication traffic is congested. A wireless frame used in a communication method conforming to this standard may be called a UHR (Ultra High Reliability) PPDU. PPDU is an abbreviation for PLCP Protocol Data Unit, and PLCP is an abbreviation 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 100 may 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 100 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 100 may also support communication standards such as wired LAN. The AP 101 is, for example, but not limited to, a wireless LAN router, a personal computer (PC), etc. The AP 101 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.The STAs 102 to 104 may be, for example, cameras, tablets, smartphones, PCs, mobile phones, video cameras, headsets, smart glasses, wearable devices such as HMDs (head-mounted displays), etc., but are not limited to these. The STAs 102 to 104 may be information processing devices such as wireless chips capable of performing wireless communication that supports the transmission and reception of PPDUs conforming to the IEEE802.11bn standard or the like. In this case, various controls can be configured to be performed by hardware circuits within the wireless chip. Note that various processes can also be configured to be performed by cooperation between a processor, memory, and hardware circuits such as an ASIP within the wireless chip. ASIP stands for Application-Specific Instruction Set Processor.

[0012] The communication device 100 may communicate using radio signals in frequency bands such as the 2.4 GHz band, the 3.6 GHz band, the 5 GHz band, the 6 GHz band, and the 45 GHz band and 60 GHz band, which are known as millimeter waves. The frequency bands used by the communication device 100 are not limited to these bands and may include, for example, the sub-1 GHz band. The communication device 100 may also 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 100 are not limited to these bands and may include, for example, 240 MHz and 4 MHz. The IEEE 802.11 standard series defines 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, the communication device 100 can use a channel in combination with an adjacent channel. This use of a channel in combination with an adjacent channel may be called channel bonding. A bundle of channels formed by one or two or more adjacent channels may be called a communication link. For example, a link formed by two 20-MHz-bandwidth channels may 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 may be continuous or discontinuous on the frequency axis. The AP 101 and the 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] The communication device 100 establishes one or more links between the devices to communicate data with other communication devices. For example, each of the STAs 102 to 104 executes a connection procedure with the AP 101 to establish a link with the AP 101. The connection procedure includes, for example, each of the STAs 102 to 104 transmitting a connection request and the AP 101 transmitting a connection response. When the connection procedure is completed, a link is established between each of the STAs 102 to 104 and the AP 101. The establishment of a link is sometimes referred to as the establishment of a connection. When a link is established, the communication device 100 can access a wireless medium and communicate data, etc., with the other communication device. For example, when a link using a 160 MHz bandwidth is established between the devices, the communication device 100 communicates using all or some of the channels that make up the link. For example, a link using a 160 MHz bandwidth can be configured by bundling eight channels with a 20 MHz bandwidth. Each of the STAs 102 to 104 can disconnect the link established with the AP 101. Disconnecting the link involves each of the STAs 102 to 104 transmitting a disconnection request and the AP 101 transmitting a disconnection response.

[0014] When transmitting a signal using a link established with another communication device, the communication device 100 performs carrier sensing to determine whether transmission is possible. Carrier sensing is an operation in which the communication device 100 determines whether a signal is present on a channel that the communication device 100 intends to use for transmission. For example, the communication device 100 measures the strength of a signal received on a channel (received signal strength) and determines that a signal is present when 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 100 may also determine the presence or absence of a signal based on information such as a Duration field included in the signal received on the channel (virtual carrier sensing). For example, the communication device 100 stores the period indicated by the Duration field included in the received signal as a Network Allocation Vector (NAV) within the communication device 100. The communication device 100 may treat the stored NAV as a period during which the communication device 100 does not transmit. In this embodiment, the operation of the communication device 100 to set a period during which the 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 100 determines that a signal is present on the channel until the NAV set for the channel expires. In this manner, the communication device 100 determines whether a signal is present on the channel based on the results of performing physical carrier sensing and virtual carrier sensing. If the communication device 100 determines that a signal is present on the channel, it may determine that transmission is not possible. In this case, the channel state may be referred to as a busy state. On the other hand, a state in which no signal is detected on the channel by carrier sensing and no NAV is set may be referred to as an idle state. If the channel is in an idle state, the communication device 100 may determine that transmission is possible.

[0015] For example, when communicating using a 160-MHz-bandwidth link, the communication device 100 may determine whether to transmit using only the 20-MHz-bandwidth Primary Channel (PCH) included in the link. The PCH is one of eight 20-MHz-bandwidth channels constituting the 160-MHz-bandwidth link. The AP 101 may notify the STAs 102 to 104 of the PCH using a periodic broadcast Beacon frame. For example, the IEEE 802.11 standard series describes that the communication device 100 can start transmission 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. In other words, if the communication device 100 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 channel other than the PCH is idle during a PIFS period immediately before the start of transmission, the communication device 100 may perform transmission by channel bonding using the idle channel and the PCH. PIFS is an abbreviation for Priority Interframe Space. Furthermore, if the communication device 100 determines that transmission is not possible as a result of performing carrier sensing on the PCH, it may postpone transmission even if other channels included in the same link are idle. Note that each channel other than the PCH that constitutes one link may be referred to as a secondary channel (SCH). A secondary channel may also be referred to as a non-primary channel (NPCH).

[0016] When a communication device 100 receives a signal on a certain channel, if a signal is transmitted on another channel (e.g., an adjacent channel) that is located at a frequency close to the received channel, the received signal may not be properly received. For example, assume that the communication device 100 can simultaneously perform transmission and reception processes using different channels. If the communication device 100 receives a signal on a certain channel and then transmits on an adjacent channel, the power of the transmitted signal will leak into the channel of the received signal, causing interference with the received signal. Generally, the power of the transmitted signal leaking in is much greater than the received power of the received signal, so the received signal will not be properly received. 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 will 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.

[0017] However, as the IEEE 802.11 standard series has expanded, the bandwidth used in a single link has become larger, and therefore, a communication method that requires the use of the PCH as described above may not be able to efficiently utilize frequency resources. For example, if the PCH is busy and other idle channels (NPCHs) are not used, this may hinder efficient use of frequency resources across the entire link. FIG. 2A shows an example of a time chart when the STA 102 transmits data to the AP 101. In FIG. 2A, the 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 the seven NPCHs other than the PCH are idle, other communication devices are not permitted to communicate using the NPCHs. FIG. 2B shows another example of a time chart when the STA 102 transmits data to the AP 101. In FIG. 2B, while STA 102 is performing carrier sensing on the PCH, the PCH is being used in another network (e.g., network 11 in FIG. 1) located geographically near STA 102. In this case, STA 102 determines that the PCH is busy during carrier sensing. Therefore, even if, for example, seven NPCHs other than the PCH are idle, STA 102 is not permitted to communicate with AP 101 using the NPCH. However, because AP 101 is not transmitting at this time, even if STA 102 transmits to AP 101 using the NPCH, AP 101 can properly receive the signal transmitted by STA 102. In this way, if, for example, a 20-MHz bandwidth PCH is being used by another network, the remaining 140-MHz idle NPCH is not utilized, resulting in inefficient use of frequency resources.

[0018] In contrast, when a PCH is being used by another communication device, the communication device 100 may perform communication between the communication devices using an NPCH included in the same link as the PCH, without using the PCH, based on whether a predetermined condition is satisfied. As an example, the communication device 100 sets a Secondary Primary Channel (SPCH) to be used to acquire a transmission right for transmitting using the NPCH when the PCH is busy. The SPCH is one or more channels among the NPCHs included in the same link as the PCH. Note that the SPCH may be called by other names, such as a Primary Secondary Channel (PSCH). If the communication device 100 determines that the PCH is being used by a communication device in another network (OBSS), it then determines whether transmission on the SPCH is possible. For example, the communication device 100 may identify the source of a signal being communicated on the PCH, thereby determining whether the PCH is being used by a communication device in its own BSS or a communication device in the OBSS. Then, when the communication device 100 determines that transmission is possible in the SPCH, it performs transmission using one or more NPCHs including the SPCH. In this embodiment, a communication method of performing transmission using one or more channels including the SPCH without using the PCH is called NPCH access (Non-Primary Channel Access). NPCH access may be called NPCA. Note that this communication method may be called by other names. For example, this communication method may be called SCA (Secondary Channel Access). In this way, when the communication device 100 acquires a transmission right using the first channel (PCH), it performs communication using a first communication method configured to enable communication by bonding the first channel and one or more second channels (NPCHs) different from the first channel. On the other hand, when the communication device cannot use the first channel, it acquires a transmission right using a third channel (SPCH) included in the second channel when certain additional conditions are met, and performs communication using a second communication method using at least the third channel.The certain additional condition may be, for example, that the PCH is used by the OBSS and the SPCH is not used. By configuring communication using a plurality of communication methods including these, the communication device 100 can communicate efficiently by using the NPCH, which has a small impact on the PCH, even when the PCH is used. Note that in the first communication method, the communication device 100 may use only the PCH without using the NPCH.

[0019] Here, even a communication device that communicates in accordance with the IEEE 802.11 standard series may not be able to perform NPCH access. For example, the communication device 100 may not have the ability to perform NPCH access. As an example, in the case of a terminal that communicates with a relatively small amount of traffic and does not require strict latency characteristics, such as a sensor device, the function to perform NPCH access may be reduced, resulting in no ability to perform NPCH access. Furthermore, even if the communication device 100 has the ability to perform NPCH access, the function to perform NPCH access may be disabled. As an example, in the case of a battery-powered terminal, some of the functions of the terminal may be disabled to reduce power consumption when the battery level is low. In this way, when there is a communication device that does not perform NPCH access, the operation of the other communication device may become inefficient. For example, the AP 101 may perform monitoring on the NPCH to receive data addressed to the AP 101 on the NPCH, even if none of the terminals connected to the AP 101 are able to perform NPCH access. In this case, power for monitoring on the NPCH is consumed in the AP 101. However, if there is no terminal that is in a state where it can perform NPCH access, data addressed to the AP 101 is not transmitted on the NPCH. Therefore, monitoring for receiving data on the NPCH by the AP 101 can be an inefficient operation for the AP 101.

[0020] In consideration of these circumstances, the communication device 100 in this embodiment enables or disables the NPCH access function of the communication device 100 based on whether other communication devices connected to the communication device 100 are capable of performing NPCH access. For example, the communication device 100 communicates with other communication devices using multiple communication methods including a first communication method and a second communication method. The first communication method may be a communication method configured to enable communication by bonding a first channel with one or more second channels different from the first channel. For example, the first channel may be a PCH. The second channel may be an NPCH. The second communication method may be a communication method in which, when the first channel cannot be used, a transmission right is acquired using a third channel included in the second channel and communication is performed using at least the third channel. The third channel may be an SPCH. The communication device 100 acquires, from the other communication devices connected to the communication device 100, identification information used to identify whether each communication device is capable of performing communication using the second communication method. Then, the communication device 100 enables or disables communication using the second communication method in the own device based on whether other communication devices connected to the own device are in a state where they can communicate using the second communication method. For example, the identification information may be information indicating whether they have the ability to perform communication using the second communication method. Furthermore, the identification information may be information indicating that communication using the second communication method is to be enabled. Furthermore, the identification information may be information indicating that communication using the second communication method is to be disabled. The communication device 100 may disable communication using the second communication method in the own device based on determining that a predetermined percentage or more of other communication devices connected to the own device are not in a state where they can communicate using the second communication method. Furthermore, the communication device 100 may enable communication using the second communication method in the own device based on determining that a predetermined percentage or more of other communication devices connected to the own device are in a state where they can communicate using the second communication method.With this configuration, the communication device 100 can enable or disable the second communication method in the device itself based on whether another communication device connected to the device itself is in a state where it can execute communication using the second communication method. As a result, the communication device 100 does not monitor the NPCH when a communication device connected to the device itself is not in a state where it can execute NPCH access, and therefore can operate efficiently. An example configuration and processing example of the communication device 100 that operates in this way will be described below.

[0021] (Device configuration) 3 shows an example of the hardware configuration of the communication device 100 of this embodiment. As an example of the hardware configuration, the communication device 100 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. The communication device 100 may have multiple antennas.

[0022] The storage unit 301 is configured with one or more memories including ROM, RAM, etc., and may store various information such as control programs for each functional unit constituting the communication device 100 to perform various operations, and parameters for communication. ROM and RAM stand for Read Only Memory and Random Access Memory, respectively. The storage unit 601 may be configured to include, in addition to memories such as ROM and RAM, 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, and a DVD.

[0023] The control unit 302 is configured with one or more processors including, for example, a CPU, an MPU, etc., and controls the entire communication device 100 by executing a control program stored in the storage unit 301. The control unit 302 may control the entire communication device 100 in cooperation with the control program stored in the storage unit 301 and an OS (Operating System). The CPU and MPU are abbreviations for Central Processing Unit and Micro Processing Unit, respectively. When the control unit 302 has multiple processors that can be implemented using a multi-core or the like, the entire communication device 100 may be configured to be controlled by the multiple processors.

[0024] Furthermore, the control unit 302 controls the functional unit 303 to execute predetermined processes such as communication, image capture, printing, and projection. The functional unit 303 is hardware that enables the communication device 100 to execute the predetermined processes described above. For example, if the device is a camera, the functional unit 303 is an image capture unit that performs image capture processing. For example, if the device is a printer, the functional unit 303 is a print unit that performs print processing. For example, if the device is a projector, the functional unit 303 is a projection unit that performs projection processing.

[0025] The input unit 304 receives various operations from the user. The output unit 305 outputs various types of information to the user via a monitor screen or a speaker. The output from the output unit 305 may be a display on a monitor screen, an audio output from a speaker, a vibration output, or the like. The input unit 304 and the output unit 305 may both be implemented as a single module, such as a touch panel. The input unit 304 and the output unit 305 may be integrated into the communication device 100 or may be separate devices.

[0026] The communication unit 306 controls 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. The communication unit 306 controls the antenna 307 to transmit and receive signals for wireless communication generated by the control unit 302. The communication unit 306 is a so-called wireless chip and may itself include one or more processors and memories. If the communication device 100 supports other wireless communication standards, such as the NFC standard or the Bluetooth standard, or wired communication, such as a wired LAN, in addition to the IEEE 802.11bn standard, the communication unit 306 may control communication compliant with these communication standards. If the communication device 100 can perform wireless communication compliant with multiple communication standards, the communication device 100 may be configured to have separate communication units and antennas compatible with each communication standard. The communication device 100 communicates data with a partner communication device via the communication unit 306. The antenna 307 may be configured separately from the communication unit 306, or may be configured as a single module together with the communication unit 306. When the communication device 100 is configured to simultaneously perform carrier sensing of multiple SPCHs, the communication device 100 may include as many communication units 306 as necessary for that purpose.

[0027] Antenna 307 is an antenna capable of communication in, for example, the 2.4 GHz band, 5 GHz band, 6 GHz band, and millimeter waves such as the 45 GHz band and 60 GHz band. While FIG. 3 shows a configuration in which communication device 100 has two antennas 307, communication device 100 may have one or three or more antennas, or one or more antennas for each frequency band that the device can use. Furthermore, when communication device 100 has multiple antennas, communication device 100 may have a communication unit 306 for each antenna. Antenna 307 may be physically configured with two or more antennas to achieve (multi-input and multi-output) transmission and reception.

[0028] (Functional configuration) 4 shows an example of the functional configuration of the communication device 100. The functional configuration in this embodiment is an example of a functional configuration realized by, for example, one or more processors executing programs stored in one or more memories. The communication device 100 can be configured to include a wireless communication control unit 401, an information acquisition unit 402, an NPCA control unit 403, and an information notification unit 404.

[0029] The wireless communication control unit 401 communicates with other communication devices using the communication unit 306. For example, the wireless communication control unit 401 performs carrier sensing of the PCH and NPCH, and communicates using a first communication method or a second communication method based on the respective statuses. For example, when the PCH is idle, the wireless communication control unit 401 communicates using the first communication method. On the other hand, when the PCH is busy, the wireless communication control unit 401 determines whether a predetermined condition is satisfied, and, if the predetermined condition is satisfied, communicates using the second communication method. Furthermore, the wireless communication control unit 401 communicates using the second communication method based on the NPCH access function being enabled in the device itself. The wireless communication control unit 401 does not communicate using the second communication method based on the NPCH access function being disabled in the device itself.

[0030] The information acquisition unit 402 acquires specific information that can identify whether a communication device connected to the device itself is in a state capable of executing the second communication method. For example, the information acquisition unit 402 can acquire, as the specific information, capability information that indicates whether the other communication device is capable of executing communication using the second communication method. The information acquisition unit 402 can also acquire, as the specific information, capability information that indicates whether the other communication device has enabled a function to execute communication using the second communication method. The information acquisition unit 402 may also acquire information other than the above as information that can identify whether the other communication device is in a state capable of executing the second communication method.

[0031] The NPCA control unit 403 controls whether to enable the function of performing communication using the second communication method in the wireless communication control unit 401 based on whether the communication devices connected to the device are in a state where they can perform communication using the second communication method. For example, the NPCA control unit 403 may disable the function of performing communication using the second communication method based on the fact that a predetermined percentage or more of the communication devices connected to the device are not in a state where they can perform communication using the second communication method. Furthermore, the NPCA control unit 403 may enable the function of performing communication using the second communication method based on the fact that a predetermined percentage or more of the communication devices connected to the device are in a state where they can perform communication using the second communication method.

[0032] The information notification unit 404 notifies another communication device whether or not the own device is in a state capable of executing communication using the second communication method. For example, the information notification unit 404 may notify the other communication device that the own device is in a state capable of executing communication using the second communication method based on enabling a function for performing communication using the second communication method in the own device. Furthermore, the information notification unit 404 may notify the other communication device that the own device is not in a state capable of executing communication using the second communication method based on disabling a function for performing communication using the second communication method in the own device. Note that, in a connection procedure for establishing a connection with another communication device, the information notification unit 404 may notify the other communication device whether or not the own device is in a state capable of executing communication using the second communication method.

[0033] (Example of processing executed by AP and each STA) Hereinafter, several examples of the flow of processing executed by the AP 101 and each STA in this embodiment will be described.

[0034] (Processing when enabling and disabling the NPCH access function) The following describes the process performed by the communication device 100 when enabling and disabling the NPCH access function. In this example, the communication device 100 is assumed to have the capability to perform NPCH access and to be able to enable or disable the NPCH access function. The communication device 100 enables or disables the NPCH access function of the communication device 100 based on whether the communication device connecting to the communication device 100 is capable of performing the NPCH access function. FIG. 5 shows an example of a process flow in which the communication device 100, while performing a connection procedure with another communication device, identifies that the other communication device has the capability to perform NPCH access and enables the NPCH access function of the communication device 100 based on the identification result. The following description uses the operation performed when the AP 101 connects to the STA 102 as an example, but the description can also be applied to the operation performed when the STA 102 connects to the AP 101. Unless otherwise specified, the AP 101 is assumed to have the NPCH access function disabled before performing the illustrated process. In FIG. 5, an example will be described in which the AP 101 determines that the STA 102 is in a state in which it can perform NPCH access, based on the fact that the STA 102 has the capability to perform NPCH access.

[0035] The AP 101 starts a connection procedure with the STA 102 (S501). For example, the AP 101 may periodically transmit a Beacon frame to allow other communication devices to detect its presence. For example, the Beacon frame may include the MAC address of the AP 101, information identifying the BSS configured by the AP 101, capability information of the AP 101, communication parameters usable for communication with the AP 101, and the like. When the STA 102 detects the AP 101 by receiving the Beacon frame transmitted by the AP 101, the STA 102 may transmit a Probe Request frame to the AP 101. The Probe Request frame may include the MAC address of the STA 102, capability information of the STA 102, and the like. When the AP 101 receives the Probe Request frame from the STA 102, the AP 101 may respond using a Probe Response frame. Like the Beacon frame, the Probe Response frame may include the MAC address of the AP 101, information identifying the BSS configured by the AP 101, capability information of the AP 101, communication parameters usable for communication with the AP 101, and the like. When the STA 102 receives the Probe Response frame from the AP 101, the STA 102 executes a connection procedure. For example, the STA 102 may exchange authentication frames, or exchange an association request frame addressed to the AP 101 with an association response frame addressed to the STA 102, and the like. The AP 101 may notify the STA 102 of information indicating whether or not the STA 102 is capable of performing NPCH access, using a Beacon frame, a Probe Response frame, an Association Response frame, and the like. For example, the AP 101 may notify the STA 102 of capability information indicating that the STA 102 is capable of performing NPCH access and information indicating that the STA 102 has an NPCH access function enabled, as information indicating that the STA 102 is capable of performing NPCH access. The STA 102 can notify the AP 101 of information indicating whether or not the STA 102 is in a state in which it can perform NPCH access, using a Probe Request frame, an Association Request frame, or the like.For example, the STA 102 may notify capability information indicating that the own device has the capability to perform NPCH access, as information indicating that the own device is in a state in which it can perform NPCH access.

[0036] The AP 101 determines whether the STA 102 is in a state where it can execute NPCH access based on the information notified by the STA 102 (S502). The AP 101 can determine that the STA 102 is in a state where it can execute NPCH access, for example, by acquiring capability information indicating that the STA 102 is capable of executing NPCH access. The AP 101 can determine that the STA 102 is not in a state where it can execute NPCH access, for example, by acquiring capability information indicating that the STA 102 is not capable of executing NPCH access. The AP 101 can also determine that the STA 102 is not in a state where it can execute NPCH access by not receiving capability information indicating that it is capable of executing NPCH access from the STA 102. If the AP 101 determines that the STA 102 is not in a state where it can execute NPCH access (NO in S502), it completes the connection procedure with the STA 102 and establishes a connection (S506). In this case, the AP 101 does not execute NPCH access in communication with the STA 102.

[0037] When the AP 101 determines that the STA 102 is in a state where it can execute NPCH access (YES in S502), it checks the status of the NPCH access function of its own device (S503). When the NPCH access function of its own device is disabled (NO in S503), the AP 101 enables the NPCH access function of its own device (S504). Based on the fact that the NPCH access of its own device is enabled (YES in S503 or the enablement is executed in S504), the AP 101 notifies the STA 102 that it is in a state where it can execute NPCH access (S505). As a result, the AP 101 and the STA 102 mutually share the fact that the other communication device is in a state where it can execute NPCH access. The AP 101 can be notified by the STA 102 that the STA 102 is in a state where it can execute NPCH access using a Probe Request frame. In this case, the AP 101 may perform S504 before transmitting a Probe Response frame and use the Probe Response frame to notify that the AP 101 is in a state where it can perform NPCH access. The STA 102 may also notify the AP 101 that the STA 102 is in a state where it can perform NPCH access using an Association Request frame. In this case, the AP 101 may perform S504 before transmitting an Association Response frame and use the Association Response frame to notify the AP 101 that it is in a state where it can perform NPCH access. The AP 101 establishes a connection by completing a connection procedure with the STA 102 (S506). In this case, the AP 101 may perform NPCH access in communication with the STA 102. In this way, the AP 101 may identify that the STA 102 is in a state where it can perform NPCH access during the connection procedure with the STA 102, and may enable the NPCH access function of the AP 101 based on the fact that the STA 102 is in a state where it can perform NPCH access. This allows AP101 to change from a state in which its own device has disabled the NPCH access function to a state in which it can enable NPCH access as needed, thereby enabling AP101 to operate efficiently.

[0038] The AP 101 may determine that the STA 102 is capable of executing NPCH access based on the fact that the STA 102 has the capability to execute NPCH access and that the STA 102 has enabled the NPCH access function. Even if the STA 102 has the capability to execute NPCH access, the STA 102 may disable the NPCH access function. This configuration allows the AP 101 to enable the NPCH access function of its own device when the STA 102 has enabled the NPCH access function, thereby enabling more efficient operation. FIG. 6 shows an example of a processing flow when the AP 101 enables the NPCH access function of its own device based on the fact that the STA 102 has the capability to execute NPCH access and that the NPCH access function has been enabled. In FIG. 6, the same reference numerals are used for processes that operate in the same way as in FIG. 5, and descriptions thereof will be omitted. That is, when the AP 101 determines that the STA 102 has the capability to execute NPCH access during the connection procedure with the STA 102 (YES in S502), it determines whether the STA 102 has enabled the NPCH access function (S601). For example, the AP 101 can determine whether the STA 102 has enabled the NPCH access function by obtaining information indicating whether the STA 102 has enabled the NPCH access function from a Probe Request frame or a Probe Response frame received from the STA 102. If the AP 101 does not determine that the STA 102 has enabled the NPCH access function (NO in S601), the AP 101 completes the connection procedure with the STA 102 and establishes a connection (S506). For example, the AP 101 can determine that the STA 102 has disabled the NPCH access function by obtaining information indicating that the NPCH access function has been disabled from the STA 102. In this case, the AP 101 does not perform NPCH access in communication with the STA 102.

[0039] When the AP 101 determines that the STA 102 has enabled the NPCH access function (YES in S601), it checks the status of the NPCH access function of its own device (S503). When the NPCH access function of its own device is disabled (NO in S503), the AP 101 enables the NPCH access function of its own device (S504). Based on the fact that the NPCH access of its own device has been enabled (YES in S503 or the enablement was performed in S504), the AP 101 notifies the STA 102 that it is in a state where it can execute NPCH access (S505). The AP 101 establishes a connection by completing a connection procedure with the STA 102 (S506). In this case, the AP 101 may use NPCH access in communication with the STA 102.

[0040] The AP 101 may enable the NPCH access function of its own device based on the determination that the STA 102 will enable the NPCH access function. For example, the STA 102 may disable the NPCH access function of its own device when establishing a connection, and enable the NPCH access function after establishing the connection. With this configuration, the AP 101 enables the NPCH access function of its own device even if the STA 102 enables the NPCH access function after establishing a connection. This allows the AP 101 to flexibly adapt its operating state to the status of the STA 102. FIG. 7 shows an example of a processing flow when the AP 101 enables the NPCH access function of its own device based on the STA 102 enabling the NPCH access function. In FIG. 7, the same reference numerals are used for processes that operate in the same way as in FIG. 5 or FIG. 6, and descriptions thereof will be omitted. That is, after establishing a connection with the STA 102, the AP 101 receives a notification from the STA 102 indicating that the NPCH access function will be enabled (S701). For example, the STA 102 may use an Action frame to notify the AP 101 that the NPCH access function will be enabled. The STA 102 may also use an Initial Control frame to notify the AP 101 of the enabled or disabled state of the NPCH access function of the STA 102 even after establishing a connection with the AP 101, by using an Action frame or an Initial Control frame. The frame used by the STA 102 to notify the AP 101 that the STA 102 has enabled or disabled the NPCH access function is not limited to these. The STA 102 may notify the AP 101 that the STA 102 has enabled or disabled the NPCH access function by using any frame communicated with the AP 101 after establishing a connection. In the following example in which the communication device 100 uses an Action frame to make a notification, the communication device 100 may similarly notify the AP 101 by using any frame communicated with the AP 101 after establishing a connection.

[0041] When the AP 101 receives notification that the STA 102 has enabled the NPCH access function, the AP 101 checks the status of the NPCH access function of the own device (S503). If the NPCH access function of the own device is disabled (NO in S503), the AP 101 enables the NPCH access function of the own device (S504). Based on the NPCH access function of the own device being enabled (YES in S503 or enabled in S504), the AP 101 notifies the STA 102 that the own device is in a state where it can execute NPCH access (S505). This allows the AP 101 and the STA 102 to mutually share information that the other communication device is in a state where it can execute NPCH access. The AP 101 can notify the STA 102 that it is in a state where it can execute NPCH access by transmitting an ACK frame in response to the Action frame or Initial Control frame received from the STA 102. In these cases, the AP 101 may perform NPCH access in communication with the STA 102.

[0042] Note that, when the AP 101 has disabled the NPCH access function, the AP 101 may enable the NPCH access function of the own device based on whether a predetermined percentage or more of the STAs connected to the own device have enabled the NPCH access function. For example, if the predetermined percentage is set to 0%, the AP 101 may enable the NPCH access function of the own device based on whether one STA has enabled the NPCH access function. Alternatively, if the predetermined percentage is set to 50%, the AP 101 may not enable the NPCH access function of the own device until two or more of the STAs 102 to 104 connected to the own device have enabled the NPCH access function. If the AP 101 enables the NPCH access function of the own device based on whether a predetermined percentage or more of the STAs connected to the own device have enabled the NPCH access function, the AP 101 may notify its own BSS that it has enabled the NPCH access function. For example, the AP 101 may use a Beacon frame to notify that it has enabled the NPCH access function. The STA 102 can enable the NPCH access function of its own device based on the fact that it has determined by receiving the Beacon frame that the AP 101 has enabled the NPCH access function.

[0043] On the other hand, the AP 101 may disable the NPCH access function of its own device based on the fact that the STA connected to the AP 101 is not in a state where it can perform NPCH access. For example, the STA 102 may enable the NPCH access function of its own device when establishing a connection, and disable the NPCH access function after establishing the connection. With this configuration, the AP 101 disables the NPCH access function of its own device even if the STA 102 disables the NPCH access function after establishing a connection. This enables the AP 101 to flexibly improve the efficiency of the operation of its own device based on the state of the STA 102. FIG. 8 shows an example of a processing flow when the AP 101 disables the NPCH access function of its own device based on the STA 102 disabling the NPCH access function. After establishing a connection with the STA 102, the AP 101 receives a notification from the STA 102 indicating that the NPCH access function will be disabled (S801). For example, the STA 102 may use an Action frame to notify the AP 101 of the fact that the NPCH access function will be disabled. The STA 102 may use an Initial Control frame to notify that the NPCH access function will be disabled. The AP 101 determines whether a predetermined percentage or more of the STAs connected to the AP 101 are in a state in which NPCH access cannot be performed (S802). For example, if the predetermined percentage is set to 100%, the AP 101 may disable the NPCH access function of the AP 101 based on the fact that all the STAs connected to the AP 101 have disabled the NPCH access function. Alternatively, if the predetermined percentage is set to 50%, the AP 101 may disable the NPCH access function of the AP 101 based on the fact that two or more of the STAs 102 to 104 connected to the AP 101 have disabled the NPCH access function.

[0044] When the AP 101 determines that a predetermined percentage or more of the STAs connected to the AP 101 are in a state in which NPCH access cannot be performed (YES in S802), the AP 101 checks the status of the NPCH access function of the AP 101 (S803). When the NPCH access function of the AP 101 is enabled (YES in S803), the AP 101 disables the NPCH access function of the AP 101 (S804). Based on the fact that the NPCH access of the AP 101 is disabled (NO in S803 or the disabling is performed in S804), the AP 101 notifies its own BSS that the AP 101 is in a state in which NPCH access cannot be performed (S805). For example, the AP 101 may use a Beacon frame to notify that the AP 101 has disabled the NPCH access function. This may notify each STA connected to the AP 101 that the AP 101 has disabled the NPCH access function. Based on the fact that the AP 101 has disabled the NPCH access function, the STA connected to the AP 101 may disable the NPCH access function of the AP 101.

[0045] (Processing when sending data) The operation of the communication device 100 when performing channel access and transmitting data will be described. FIG. 9 shows an example of a processing flow when the communication device 100 communicates data. This processing flow can be executed when one or more other communication devices are connected to the communication device 100 and data communication is being performed between these communication devices. First, when the communication device 100 detects that data has accumulated in its transmission queue, it starts a channel access procedure to transmit the data (YES in S901). First, the communication device 100 performs carrier sense on the PCH (S902). If the communication device 100 does not detect a signal on the PCH, it measures a backoff counter and determines whether the PCH is in an idle state. That is, if the communication device 100 does not detect a signal for a period determined by the backoff counter, it determines that the PCH is in an idle state. If it determines that the PCH is in an idle state (YES in S902), the communication device 100 transmits a signal using one or more channels including the PCH. Note that the communication device 100 may perform carrier sensing of the NPCH for a predetermined period after determining that the PCH is in an idle state. Furthermore, the communication device 100 may perform carrier sensing of the NPCH in parallel with carrier sensing of the PCH. The communication device 100 may determine a channel to use for transmission based on the results of carrier sensing performed on each of the PCH and the NPCH, and transmit a signal. For example, the communication device 100 may transmit a signal using the PCH and one or more NPCHs determined to be in an idle state.

[0046] If a signal is detected in the carrier sense (NO in S902), the communication device 100 sets the NAV for the PCH using the duration indicated in the Duration field included in the received signal. The communication device 100 also determines whether the signal was transmitted from a communication device of its own BSS. For example, the communication device 100 may determine whether the signal is from its own BSS or from an OBSS based on whether the BSS Color field included in the received signal matches the BSS Color of its own BSS. The communication device 100 may also determine whether the signal is from its own BSS or from an OBSS based on whether the values ​​stored in the destination field, source field, etc. included in the received signal match the parameters of its own BSS. If the signal detected in the PCH is a signal from its own BSS, the communication device 100 may determine not to perform NPCH access. In this case, the communication device 100 postpones transmission until the NAV set for the PCH expires.

[0047] When the communication device 100 determines that the signal received on the PCH is an OBSS signal, it determines whether to execute NPCH access (S904). For example, the communication device 100 checks whether the NPCH access function is enabled in the communication device 100 itself. When the NPCH access function is disabled in the communication device 100 (NO in S904), the communication device 100 determines not to execute NPCH access and postpones transmission until the NAV set in the PCH expires. Furthermore, when the communication device 100 itself has enabled the NPCH access function, it determines whether the destination of the data to be transmitted is in a state where NPCH access can be executed. For example, the STA 102 determines whether the AP 101 is in a state where NPCH access can be executed. For example, when there are multiple STAs connected to the communication device 100, the AP 101 determines whether the STA to which the data is to be transmitted is in a state where NPCH access can be executed. In order to determine whether the other communication device is in a state where it can execute NPCH access, the communication device 100 may retain the state of each communication device in itself when establishing a connection or when receiving notification of a subsequent change in state, and may update the state in response to the notification. If the other communication device has disabled the NPCH access function (NO in S904), the communication device 100 may determine not to execute NPCH access and postpone transmission until the NAV set in the PCH expires. On the other hand, if the communication device 100 and the other communication device have enabled the NPCH access function (YES in S904), the communication device 100 may determine to attempt NPCH access.

[0048] When the communication device 100 determines to attempt NPCH access, it performs carrier sensing of the SPCH (S905). Note that if multiple SPCHs are set between the communication devices, the communication device 100 performs carrier sensing in descending order of priority assigned to the SPCHs. Furthermore, if the communication device 100 can perform carrier sensing on multiple SPCHs in parallel, it may perform carrier sensing on multiple SPCHs selected in descending order of priority assigned to the SPCHs. When the communication device 100 determines that the SPCH is idle (YES in S905), it performs NPCH access (S906). For example, the communication device 100 may transmit a signal using one or more SPCHs and NPCHs determined to be idle. For example, the communication device 100 may perform carrier sensing on the SPCH and carrier sensing on other NPCHs, and may determine a channel to use for transmission based on the results of the carrier sensing performed on each of the SPCH and NPCH, and transmit a signal.

[0049] When the communication device 100 detects a signal in the SPCH (NO in S904), it determines whether the detected signal is a signal from its own BSS or an OBSS. If the detected signal is a signal from its own BSS, it may cancel NPCH access and postpone transmission until the NAV period set in the PCH expires. If the detected signal is a signal from the OBSS, the communication device 100 determines whether there are other SPCHs for which carrier sense is not being performed (S907). If there are other SPCHs (YES in S907), it performs carrier sense in descending order of the priority assigned to the SPCHs (S905). The communication device 100 performs carrier sense in descending order of the priority assigned to the SPCHs, and if all SPCHs are busy (NO in S907), it postpones transmission until the NAV period set in the PCH expires.

[0050] (Processing when receiving data) Next, the operation of the communication device 100 when receiving data will be described. When no data is stored in the transmission queue of the communication device 100 (NO in S901), the communication device 100 monitors signals on the channel to receive data from the other communication device. For example, the communication device 100 monitors the presence or absence of a signal on the PCH. When a signal is detected on the PCH (YES in S911), the communication device 100 determines whether the signal is from the own BSS or an OBSS (S912). When the signal is from the own BSS (YES in S912), the communication device 100 determines whether the signal is addressed to the communication device 100. When the signal is addressed to the communication device 100 (YES in S917), the communication device 100 continues the reception process (S918). When the signal is not addressed to the communication device 100 (NO in S917), the reception process may be aborted. When the detected signal is an OBSS signal (NO in S912), the communication device 100 sets the NAV on the PCH. Furthermore, the communication device 100 determines whether or not to perform monitoring on the SPCH (S913). For example, the communication device 100 checks whether or not the device itself has enabled the NPCH access function. If the device itself has disabled the NPCH access function (NO in S913), the communication device 100 determines not to perform monitoring on the SPCH and waits until the NAV set in the PCH expires (S919). Furthermore, if the device itself has enabled the NPCH access function (YES in S913), the communication device 100 can perform monitoring on the SPCH.

[0051] When the communication device 100 has enabled the NPCH access function, it monitors the presence or absence of a signal on the SPCH in preparation for receiving a signal via NPCH access from a communication device at a remote location (S914). When the communication device 100 detects a signal on the SPCH (YES in S914), it determines whether the signal is from its own BSS or from an OBSS. When the signal is from its own BSS (YES in S915), the communication device 100 determines whether the signal is addressed to the communication device 100 (S917). When the signal is addressed to the communication device 100 (YES in S917), the communication device 100 continues the reception process (S918). When the signal is not addressed to the communication device 100 (NO in S917), the communication device 100 may stop the reception process for the signal. When the detected signal is a signal from an OBSS, the communication device 100 may stop the reception process for the signal.

[0052] If multiple SPCHs are set, the communication device 100 may monitor the presence or absence of signals on each SPCH in parallel. If priorities are assigned to the SPCHs, the communication device 100 may monitor signals on each SPCH according to the priorities. If the communication device 100 receives an OBSS signal on a SPCH with a higher priority, it may stop monitoring that SPCH and start monitoring the SPCH with the next highest priority (YES in S916). The communication device 100 performs monitoring in descending order of the priorities assigned to the SPCHs, and if all SPCHs are busy (NO in S916), it waits until the NAV period set on the PCH expires (S920).

[0053] (Format used to notify information about NPCH access) The format of information used by the communication device 100 to notify a counterpart communication device of whether or not NPCH access is executable will be described. FIG. 10(A) shows an example of the configuration of information elements used when the communication device 100 notifies whether or not it has the capability to execute NPCH access. The information elements may be called Information Elements (IEs). FIG. 10(A) may be called an NPCA element. The NPCA element may be called by other names. The NPCA element may include capability information indicating whether or not the communication device 100 has the capability to execute NPCH access, and information related to NPCH access, such as the channel switch time required to execute NPCH access. The NPCA element may be included in management frames such as an Association Request frame and an Association Response frame. The NPCA element may also be included in a Beacon frame, a Probe Request frame, a Probe Response frame, etc.

[0054] An NPCA element may include an Element ID field 1001, a Length field 1002, an Element ID Extension field 1003, and an NPCA capable field 1004. An NPCA element may also include an NPCA Tx capable field 1005 and an NPCA Rx capable field 1006. An NPCA element may also include an NPCA Tx number field 1007, an NPCA Rx number field 1008, and a Switching Time field 1009. The Element ID field 1001 and the Element ID Extension field 1003 indicate that this element is an NPCA element. For example, the Element ID field 1001 may have a value of 255, and the Element ID Extension field 1003 may have a value of 136. A value other than 136 may be used to indicate that the Element ID Extension field 1003 is an NPCA element, provided that the value is not a value used for other purposes in legacy standards. The Length field 1002 indicates the length of this element.

[0055] The NPCA capable field 1004 indicates whether the communication device 100 transmitting the NPCA element is capable of performing NPCH access. For example, if the NPCA capable field 1004 is configured with one bit, a value of 0 may indicate that the communication device 100 is not capable of performing NPCH access, and a value of 1 may indicate that the communication device 100 is capable of performing NPCH access. The NPCA Tx capable field 1005 and the NPCA Rx capable field 1006 each indicate whether transmission and reception in NPCH access are possible. For example, in each field, a value of 0 may indicate that the communication device 100 is capable of performing transmission or reception in NPCH access, and a value of 1 may indicate that the communication device 100 is capable of performing transmission or reception in NPCH access. The NPCA Tx number field 1007 and the NPCA Rx number field 1008 each indicate the number of antennas that can be used for transmission and reception in NPCH access. The Switching Time field 1009 indicates the switching time required to change the channel for carrier sensing and monitoring when performing NPCH access. For example, the switching time indicates the time required for the communication device 100 to start carrier sensing in the SPCH from a state in which the communication device 100 is performing carrier sensing in the PCH. Note that the fields included in the NPCA element described above are merely examples, and other fields may be included, or some of these fields may not be included. Also, the names of the fields may be different from those described above. Furthermore, the roles of the above-mentioned multiple fields may be configured by one field, and the role of one field described above may be configured by multiple fields.

[0056] FIG. 10(B) shows another example configuration of the NPCA element used when notifying whether the communication device 100 is in a state where it can perform NPCH access. The NPCA element in FIG. 10(B) can be used to indicate whether the NPCH access function is enabled when the communication device 100 has the ability to perform NPCH access. In FIG. 10(B), the same information elements as those in FIG. 10(A) are given the same reference numerals, and descriptions thereof will be omitted. That is, the NPCA element shown in FIG. 10(B) differs from the NPCA element shown in FIG. 10(A) in that it includes an NPCA Operation mode 1010. The NPCA Operation mode 1010 indicates whether the communication device 100 has enabled the NPCH access function. For example, when the value of the NPCA Operation mode 1010 is set to 0, this can indicate that the communication device 100 has disabled the NPCH access function. Furthermore, when the value of the NPCA Operation mode 1010 is set to 1, this can indicate that the communication device 100 has enabled the NPCH access function. For example, the communication device 100 identifies that the NPCA capable element 1014 and the NPCA Operation mode 1010 are set to a value of 1 in the NPCA element acquired from the other communication device. Based on this identification, the communication device 100 can determine that the communication device is in a state where it can perform NPCH access. Furthermore, the communication device 100 identifies that either the NPCA capable element 1014 or the NPCA Operation mode 1010 is set to a value of 0 in the NPCA element acquired from the other communication device. Based on this identification, the communication device 100 can determine that the communication device is not in a state where it can perform NPCH access.

[0057] 10(C) shows an example of the configuration of an Action frame used for notification when the communication device 100 disables the NPCH access function from an enabled state, or when the communication device 100 enables the NPCH access function from a disabled state. The communication device may perform notification using a frame other than the Action frame. In this case, the frame used for notification may include similar information. For example, the Action frame shown in FIG. 10(C) may be referred to as an NPCA announcement frame. In FIG. 10(C), the same information elements as those in FIG. 10(A) are assigned the same reference numerals, and description thereof will be omitted. The NPCA announcement frame may include a Category field 1011, a UHR Action field 1012, a Dialog Token field 1013, and an NPCA capable field 1104. The NPCA announcement frame may also include an NPCA Operation mode 1010, an NPCA Tx capable field 1005, and an NPCA Rx capable field 1006. Furthermore, the NPCA announcement frame may include an NPCA Tx number field 1007, an NPCA Rx number field 1008, and a Switching Time field 1009. The Category field 1011 is an 8-bit field that indicates the type of Action frame. For example, the Category field 1011 may be set to a value of 38, indicating a frame for notifying information related to UHR. Note that the value set in the Category field 1011 may be another value, as long as it is a value that is not used in legacy standards. The UHR Action field 1012 is set to a value that indicates an NPCA Announcement frame. For example, the UHR Action field 1012 may be set to a value of 1, or may be set to another value that specifies an NPCA Announcement frame. The Dialog Token field 1013 indicates an identifier for executing a series of information exchanges between communication devices. For example, an identifier assigned by the communication device 100 is stored in the Dialog Token field 1013.The communication device of the other party stores the value contained in the received Dialog Token field 1013 in the Dialog Token field 1013 of a response frame and transmits it.

[0058] (Sequence exchanged between AP and STA) An example of a sequence exchanged between communication devices when the communication device 100 enables or disables the NPCH access function of the communication device itself based on whether the other communication device is capable of executing NPCH access will be described. In this example, the operation when the AP 101 connects to the STA 102 will be described as an example, but the operation in this example can also be applied to the operation when the STA 102 connects to the AP 101. FIG. 11 shows an example of a sequence in which, when executing a connection procedure with another communication device, the communication device 100 identifies that the other communication device has the function of executing NPCH access, and enables the NPCH access function of the communication device itself based on the identification result. Before executing the sequence of FIG. 11, the AP 101 is in a state in which the NPCH access function is disabled. Furthermore, in this example, the AP 101 determines that the STA 102 is capable of executing NPCH access based on the fact that the STA 102 has the ability to execute NPCH access.

[0059] The AP 101 periodically transmits a Beacon frame (F1101). The STA 102 may detect the AP 101 by receiving the Beacon frame. The STA 102 transmits a connection request to start a connection procedure with the AP 101 (F1102). For example, the connection request may include a Probe Request frame, an Authentication frame, and an Association Request frame. In the connection request, the STA 102 notifies the AP 101 that the STA 102 is capable of performing NPCH access. For example, the STA 102 may use the connection request to notify the AP 101 of information indicating that the STA 102 is capable of performing NPCH access. As an example, the STA 102 may perform this notification by transmitting a frame including an NPCA element in which the value of the NPCA capable field 1004 is set to 1.

[0060] The AP 101 determines that the STA 102 is capable of performing NPCH access by determining in the connection request received from the STA 102 that the STA 102 has the capability to perform NPCH access. Based on this determination, the AP 101 enables the NPCH access function of its own device (F1103). The AP 101 notifies the STA 102 that its own device has the NPCH access function enabled (F1104). For example, the AP 101 may notify the STA 102 that its own device has the NPCH access function enabled by using a connection response to the connection request received from the STA 102 (F1104). For example, the connection response may include a Probe Response frame, an Authentication frame, and an Association Response frame. For example, the AP 101 may notify the STA 102 of information indicating that its own device has the capability to perform NPCH access by using the connection response. As an example, the AP 101 may perform this notification by transmitting a frame including an NPCA element with the NPCA capable field 1004 set to a value of 1.

[0061] Through the above message exchange, the AP 101 and the STA 102 share the information that each other's communication device has the capability to perform NPCH access. The AP 101 and the STA 102 can use the NPCH access in subsequent data communication (F1105).

[0062] 12 shows another example sequence in which, when executing a connection procedure with another communication device, the communication device 100 identifies that the other communication device is in a state where it can execute NPCH access, and enables the NPCH access function of its own device based on the identification result. In this example, the communication device 100 determines that the other communication device is in a state where it can execute NPCH access by identifying that the other communication device has a function to execute NPCH access and that the NPCH access function is enabled. Also, in this example, after establishing a connection with the other communication device, the communication device 100 disables the NPCH access function of its own device based on receiving a notification from the other communication device that the NPCH access function will be disabled. In FIG. 12, processes that operate in the same way as in FIG. 11 are assigned the same reference numerals, and descriptions thereof will be omitted.

[0063] First, when the STA 102 detects the AP 101 by receiving a Beacon frame (F1101), it transmits a connection request to start a connection procedure with the AP 101 (F1201). For example, the STA 102 may use the connection request to notify the AP 101 of capability information indicating that the STA 102 is capable of performing NPCH access and information indicating that the STA 102 has enabled NPCH access. As an example, the STA 102 may perform this notification by transmitting a frame including an NPCA element in which the values ​​of the NPCA capable field 1004 and the NPCA Operation mode element 1010 are both set to 1.

[0064] The AP 101 acquires capability information indicating that the STA 102 is capable of performing NPCH access and information indicating that the STA 102 has enabled NPCH access from the connection request. Based on this information, the AP 101 determines that the STA 102 is in a state where it can perform NPCH access. Based on this determination, the AP 101 enables the NPCH access function of its own device (F1103). The AP 101 notifies the STA 102 that it is capable of performing the NPCH access function (F1202). For example, the AP 101 may notify the STA 102 of the capability information indicating that its own device is capable of performing NPCH access and information indicating that its own device has enabled the NPCH access function, using a connection response to the connection request received from the STA 102. As an example, the AP 101 may perform this notification by transmitting a frame including an NPCA element in which the values ​​of the NPCA capable field 1004 and the NPCA Operation mode element 1010 are both set to 1. By exchanging these messages, the AP 101 and the STA 102 share information that each other's communication device is capable of executing NPCH access. The AP 101 and the STA 102 can use NPCH access in subsequent data communication (F1105).

[0065] The STA 102 may disable the NPCH access function after establishing a connection with the AP 101. In this case, the STA 102 notifies the AP 101 that it will disable the NPCH access function. For example, the STA 102 may notify the AP 101 that it will disable the NPCH access function by using an Action frame in which the value of the NPCA Operation mode element 1010 is set to 0. The AP 101 determines whether or not it should disable the NPCH access function based on receiving the notification that the STA 102 will disable the NPCH access function. For example, the AP 101 may determine whether or not it should disable the NPCH access function based on whether a predetermined percentage or more of the STAs connected to the AP 101 are in a state in which they cannot perform NPCH access. In this example, the AP 101 determines that all STAs connected to the AP 101 are no longer in a state in which they can perform NPCH access because it has received the notification that the STA 102 will disable the NPCH access function. Based on this determination, the AP 101 disables the NPCH access function of the AP 101 (F1204). The AP 101 may notify the STA 102 and its own BSS that it has disabled the NPCH access function. For example, the AP 101 may notify the STA 102 and its own BSS that it has disabled the NPCH access function by using an Action frame or a Beacon frame in which the value of the NPCA Operation mode element 1010 is set to 0. By exchanging these messages, the AP 101 and the STA 102 are no longer able to execute NPCH access. Therefore, the AP 101 and the STA 102 do not use NPCH access in subsequent data communications (F1205).

[0066] 13 shows another example sequence in which, when executing a connection procedure with another communication device, the communication device 100 identifies that the other communication device is in a state capable of executing NPCH access, and enables the NPCH access function of the communication device itself based on the identification result. In this example, the communication device 100 determines that the other communication device is in a state capable of executing NPCH access by identifying that the other communication device has a function of executing NPCH access. Also, in this example, the communication device 100 disables the NPCH access function of the communication device itself based on the fact that, after establishing connections with multiple communication devices, the communication device 100 disconnects the connections with each of the communication devices. Note that in this example, it is assumed that STA 102 does not have the ability to execute NPCH access, and STA 103 and STA 104 have the ability to execute NPCH access.

[0067] First, when the STA 102 detects the AP 101, it transmits a connection request to initiate a connection procedure with the AP 101 (F1301). The STA 102 does not have the capability to perform NPCH access. In this case, the STA 102 may transmit the connection request including capability information indicating that it does not have the capability to perform NPCH access. As an example, the STA 102 may notify this by transmitting a frame including an NPCA element in which the NPCA capable field 1004 is set to a value of 0. The AP 101 acquires the capability information indicating that the STA 102 does not have the capability to perform NPCH access from the connection request, thereby determining that the STA 102 is not in a state where it can perform NPCH access. In this case, the AP 101 does not enable the NPCH access function of its own device. The AP 101 transmits a connection response to the STA 102 and establishes a connection with the STA 102 (F1302). In this case, the AP 101 may or may not indicate that it has the capability to perform the NPCH access function in the connection response. The AP 101 and the STA 102 do not use NPCH access in subsequent data communication (F1303).

[0068] When the STA 103 detects the AP 101, it transmits a connection request to initiate a connection procedure with the AP 101 (F1304). The STA 103 has the capability to perform NPCH access. In this case, the STA 103 may transmit the connection request including capability information indicating that it has the capability to perform NPCH access. The AP 101 acquires the capability information indicating that the STA 103 has the capability to perform NPCH access from the connection request, thereby determining that the STA 103 is in a state where it can perform NPCH access. The AP 101 may enable the NPCH access function of its own device based on the determination that the STA 103 is in a state where it can perform NPCH access (F1305). The AP 101 transmits a connection response to the STA 103 and establishes a connection with the STA 102 (F1302). The AP 101 may notify the STA 103 that it is in a state where it can perform NPCH access. For example, the AP 101 may notify the STA 103 by transmitting a connection response including capability information indicating that the AP 101 has the capability to perform the NPCH access function. By exchanging these messages, the AP 101 and the STA 103 share information that each other's communication device is capable of executing NPCH access. The AP 101 and the STA 103 can use NPCH access in subsequent data communication (F1307).

[0069] When the STA 104 detects the AP 101, it transmits a connection request to start a connection procedure with the AP 101 (F1308). Because the STA 104 has the capability to perform NPCH access, it establishes a connection with the AP 101 using the same procedure as the STA 103 and performs data communication (S1308 to S1310). This allows the AP 101 and the STA 104 to share information that the other communication device is in a state where it can perform NPCH access. The AP 101 and the STA 104 can use NPCH access in subsequent data communication (F1307).

[0070] Thereafter, the STA 104 disconnects from the AP 101. For example, the STA 104 transmits a disconnection request to the AP 101 (F1311). As an example, the STA 104 may make the disconnection request using a Deauthentication frame. In response to receiving the disconnection request from the STA 104, the AP 101 transmits a disconnection response (F1312). For example, the AP 101 may transmit the Deauthentication frame. At this time, the AP 101 may determine whether to disable the NPCH access function of its own device based on whether the communication devices connected to the AP 101 are in a state where they can perform NPCH access. For example, the AP 101 may determine to disable the NPCH access function based on whether a predetermined percentage or more of the communication devices connected to the AP 101 are in a state where they cannot perform NPCH access. In this example, the AP 101 does not disable the NPCH access function of its own device based on the fact that the STA 103 is in a state where it can perform NPCH access.

[0071] Next, the STA 103 disconnects from the AP 101. For example, the STA 103 transmits a disconnection request to the AP 101 (F1313). When the AP 101 receives the disconnection request from the STA 103, it determines whether or not to disable the NPCH access function of its own device. In this case, the AP 101 may disable the NPCH access function based on the fact that none of the STAs connected to the AP 101 are able to perform NPCH access (F1314). Furthermore, the AP 101 transmits a disconnection response in response to the disconnection request received from the STA 103 (F1314). The AP 101 may notify the BSS that its own device has disabled the NPCH access function. In this case, the AP 101 may notify using a Beacon frame.

[0072] 14 shows another example sequence in which, when executing a connection procedure with another communication device, the communication device 100 identifies that the other communication device is in a state where it can execute NPCH access, and enables the NPCH access function of its own device based on the identification result. In this example, the communication device 100 determines that the other communication device is in a state where it can execute NPCH access by identifying that the other communication device has a function to execute NPCH access and that the NPCH access function is enabled. Also, in this example, after the communication device 100 establishes connections with multiple communication devices, the NPCH access function is disabled or enabled in each communication device.

[0073] First, when the STA 102 detects the AP 101, it transmits a connection request to start a connection procedure with the AP 101 (F1401). The STA 102 may transmit the connection request including capability information indicating that the STA 102 does not have the capability to perform NPCH access and information indicating that the STA 102 has enabled the NPCH access function. The AP 101 acquires the capability information indicating that the STA 102 does not have the capability to perform NPCH access and information indicating that the STA 102 has enabled the NPCH access function from the connection request. Based on this information, the AP 101 may determine that the STA 102 is in a state where it can perform NPCH access. Based on the determination that the STA 102 is in a state where it can perform NPCH access, the AP 101 may determine whether to enable the NPCH access function of the STA 102. For example, the AP 101 may enable the NPCH access function of the STA 102 based on the determination that a predetermined percentage or more of the communication devices connected to the STA 102 are in a state where they can perform NPCH access. In this example, the AP 101 enables the NPCH access function of its own device based on the determination that the STA 102 is in a state where it can execute NPCH access (F1402). In response to the connection request received from the STA 102, the AP 101 transmits a connection response to the STA 102 and establishes a connection with the STA 102 (F1403). The AP 101 may transmit the connection response including information indicating that its own device is in a state where it can execute NPCH access. The AP 101 and the STA 102 may use NPCH access in subsequent data communication (F1404).

[0074] When the STA 103 detects the AP 101, it transmits a connection request to start a connection procedure with the AP 101 (F1405). The STA 103 establishes a connection with the AP 101 using the same procedure as the STA 102, and performs data communication (S1405 to S1407). This allows the AP 101 and the STA 103 to share information that the other communication device is in a state where it can execute NPCH access. The AP 101 and the STA 103 can use NPCH access in subsequent data communication (F1407).

[0075] Thereafter, the STA 102 disables the NPCH access function of its own device (F1408). Furthermore, the STA 102 notifies the AP 101 that its own device will disable the NPCH access function (F1409). For example, the STA 102 may notify the AP 101 that its own device will disable the NPCH access function by using an Action frame in which the value of the NPCA Operation mode element 1010 is set to 0. The AP 101 may determine whether to disable the NPCH access function of its own device based on receiving the notification that the STA 102 will disable the NPCH access function. For example, the AP 101 may determine to disable the NPCH access function based on the fact that a predetermined percentage or more of the communication devices connected to the own device are in a state in which they cannot perform NPCH access. In this example, the AP 101 does not disable the NPCH access function of its own device based on the fact that the STA 103 is in a state in which it can perform NPCH access. The AP 101 and the STA 102 do not use NPCH access in subsequent data communications based on the shared information that the STA 102 is not in a state where it can perform NPCH access (F1410).

[0076] Next, the STA 103 disables the NPCH access function of its own device (F1411). Furthermore, the STA 102 notifies the AP 101 that its own device will disable the NPCH access function (F1412). Based on receiving the notification that the STA 102 will disable the NPCH access function, the AP 101 determines whether or not to disable the NPCH access function of its own device. In this case, the AP 101 may disable the NPCH access function based on the fact that none of the STAs connected to the own device are able to execute NPCH access (F1413). Based on the fact that the AP 101 and the STA 103 are each unable to execute NPCH access, they will not use NPCH access in subsequent data communications (F1414). Note that the AP 101 may notify its own BSS that the NPCH access function of its own device has been disabled. For example, if some of the communication devices connected to the AP 101 are able to execute NPCH access, these communication devices may determine that the AP 101 has disabled the NPCH access function and disable the NPCH access of their own devices.

[0077] Thereafter, the STA 102 enables the NPCH access function of its own device (F1415). The STA 102 notifies the AP 101 that its own device will enable the NPCH access function (F1416). For example, the STA 102 may notify the AP 101 that its own device will enable the NPCH access function by using an Action frame in which the value of the NPCA Operation mode element 1010 is set to 1. The AP 101 may determine whether to enable the NPCH access function of its own device based on receiving the notification that the STA 102 will enable the NPCH access function. For example, the AP 101 may determine to enable the NPCH access function based on a predetermined rate or more of communication devices connected to the own device being able to execute NPCH access. In this example, the AP 101 enables the NPCH access function of its own device based on the STA 102 being able to execute NPCH access (F1417). Furthermore, the AP 101 may notify the STA 102 that it has enabled NPCH access (F1418). For example, the AP 101 may use an Action frame to make the notification. The AP 101 may also notify its own BSS that it has enabled NPCH access. In this case, the AP 101 may use a Beacon frame to make the notification. A STA connected to the AP 101 may enable the NPCH access function of its own device based on the notification that the AP 101 has enabled the NPCH access function. The AP 101 and the STA 102 may use the NPCH access in subsequent data communication based on the mutual sharing that the other communication device is in a state where it can execute NPCH access (F1418).

[0078] An example of a sequence for enabling the NPCH access function and performing communication using NPCH access when the AP 101 has disabled its NPCH access function by establishing a connection between the AP 101 and a new STA will be described. In FIG. 15 , the AP 101 establishes connections with STA 102 and STA 103, and then starts a new connection with STA 104. It is assumed that STA 102 and STA 103 are unable to perform NPCH access, and the AP 101 has disabled its own NPCH access function. First, the STA 104 transmits a connection request to the AP 101. For example, the STA 104 transmits an Association Request frame 1501 to the AP 101. The Association Request frame may include the NPCA element shown in FIG. 10(A). The value of the NPCA capable field 1004 included in the Association Request frame transmitted by the STA 104 may be set to 1. This may notify the AP 101 that the STA 104 is capable of performing NPCH access.

[0079] When the AP 101 receives a connection request from the STA 104, the AP 101 determines whether the STA 104 is capable of performing NPCH access based on the NPCA element included in the connection request. For example, the AP 101 determines that the STA 104 is capable of performing NPCH access based on the value of the NPCA capable field 1004 being set to 1. Based on this determination, the AP 101 may enable the NPCH access function of its own device. The AP 101 transmits an association response in response to the connection request received from the STA 104. For example, the AP 101 transmits an association response frame 1502. The association response frame may include the NPCA element shown in FIG. 10(A). The value of the NPCA capable field 1004 included in the association response frame transmitted by the AP 101 may be set to 1. This may notify the STA 104 that the AP 101 is capable of performing NPCH access. By exchanging these frames, a connection is established between the AP 101 and the STA 104, and the AP 101 and the STA 104 share the information that the other device is in a state where it can perform NPCH access.

[0080] When AP 101 detects that data addressed to STA 104 has accumulated in the buffer, it starts accessing the channel. For example, AP 101 starts carrier sensing on the PCH and performs decrementing of the back-off counter. AP 101 may receive OBSS signal 1511 on the PCH while decrementing the back-off counter. In this case, AP 101 sets NAV 1512 on the PCH. Note that STAs 102 to 104 also set NAV 1512 on the PCH when they receive OBSS signal 1511 on the PCH.

[0081] AP 101 starts carrier sensing on SPCH based on the fact that STA 104 is in a state where it can perform NPCH access. AP 101 decrements the backoff counter on SPCH, and acquires the right to transmit when the backoff counter value reaches 0. AP 101 transmits RTS frame 1503, and upon receiving CTS frame 1504 from STA 104, transmits PPDU 1505 addressed to STA 104. AP 101 completes the transmission process by receiving ACK 1506 in response to PPDU 1505. Note that RTS is an abbreviation for Request-to-Send. Also, CTS is an abbreviation for Clear-to-Send.

[0082] On the other hand, STA 104 starts monitoring on the SPCH based on the fact that AP 101 is in a state where it can execute NPCH access. When STA 104 receives RTS frame 1503 from AP 101, it transmits CTS frame 1504. When STA 104 receives PPDU 1505 from AP 101, it transmits ACK 1506. Note that STA 102 and STA 103 do not monitor on the SPCH because they are not in a state where they can execute NPCH access.

[0083] FIG. 16 shows another example of a sequence in which, when the AP 101 has disabled the NPCH access function, a connection is established between the AP 101 and a new STA, thereby enabling the NPCH access function and performing communication using NPCH access. In this example, the AP 101 enables the NPCH access function after establishing a connection with the STA 104. The AP 101 also uses an Action frame to notify the STA 104 that it has enabled the NPCH access function. In FIG. 16, the same operations as those in FIG. 15 are assigned the same reference numerals, and descriptions thereof will be omitted. That is, in FIG. 16, the STA 104 transmits an Association Request frame 1601 including the NPCA element shown in FIG. 10(B). The values ​​of the NPCA capable field 1004 and the NPCA Operation mode included in the Association Request frame 1601 transmitted by the STA 104 may both be set to 1. Based on this information, the AP 101 may determine that the STA 104 is in a state in which it can perform NPCH access.

[0084] In response to the Association Request frame 1601 received from the STA 104, the AP 101 transmits an Association Response frame 1602 including the NPCA element shown in Fig. 10(B). The values ​​of the NPCA capable field 1004 and the NPCA Operation mode included in the Association Response frame 1602 transmitted by the AP 101 can be set to 1 and 0, respectively. In this way, the AP 101 notifies the STA 104 in the Association Response frame 1602 that the AP 101 has disabled the NPCH access function.

[0085] Thereafter, the AP 101 enables the NPCH access function. For example, the AP 101 may enable the NPCH access function of its own device based on the fact that the STA 104 is in a state where it can execute NPCH access during the connection procedure with the STA 104. In this case, the AP 101 may notify the STA 104 that it has enabled the NPCH access function of its own device using an Action frame 1603. By exchanging these frames, a connection is established between the AP 101 and the STA 104, and the AP 101 and the STA 104 share with each other that the other device is in a state where it can execute NPCH access. As a result, the AP 101 may execute data communication with the STA 104 using NPCH access, as in FIG. 15 .

[0086] As described above, according to the present embodiment, the communication device 100 can enable or disable the NPCA access function of the communication device 100 based on whether the communication device connected to the communication device 100 is capable of executing NPCA access. As a result, the communication device 100 does not attempt carrier sensing using the NPCH when the PCH is unavailable and the communication device connected to the communication device 100 is not capable of executing NPCH access. Furthermore, the communication device 100 does not monitor the NPCH when the communication device connected to the communication device 100 is not capable of executing NPCH access. In this manner, the communication device 100 can operate efficiently, thereby reducing the processing load of the communication device 100 and achieving low power consumption. While the present embodiment exemplifies a case where a communication method that does not use a PCH is referred to as NPCH access, the present invention is not limited thereto and may be referred to as, for example, secondary primary channel access. While the present embodiment exemplifies a case where a channel for determining whether transmission using the NPCH is possible is referred to as SPCH for convenience, the present invention is not limited thereto. Among multiple NPCHs, this channel has a high priority for determining whether transmission is possible, so it may also be called a PSCH (Primary Secondary Channel). Regardless of which term is used, it means that this is a channel that should be used to determine whether transmission using the NPCH is possible.

[0087] 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.

[0088] (Summary of the embodiment) At least some of the above-described embodiments can be summarized as follows. (Item 1) A communication device that communicates with one or more other communication devices using wireless frames that comply with at least one standard included in the IEEE 802.11 series of standards, a communication means for performing communication using a plurality of communication methods, including a first communication method configured to be able to communicate by bonding a first channel and one or more second channels different from the first channel, the first communication method acquiring a transmission right using the first channel to perform communication, and a second communication method acquiring a transmission right using a third channel included in the second channels to perform communication using at least the third channel when the first channel cannot be used; an acquisition means for acquiring, from each of the other communication devices connected to the communication device, identification information used to identify whether the other communication devices are in a state where they can perform communication using the second communication method; and a control means for enabling or disabling communication using the second communication method in the communication device based on whether the other communication device connected to the communication device is in a state where communication using the second communication method can be performed. A communication device comprising: (Item 2) The acquisition means uses the information indicating whether the other communication device has the ability to perform communication using the second communication method as the identification information used to identify whether the other communication device is in a state where it can perform communication using the second communication method. 2. The communication device according to item 1, (Item 3) The acquisition means uses the information indicating that the other communication device enables communication using the second communication method as the identification information used to identify whether the other communication device is in a state where it can perform communication using the second communication method. 3. The communication device according to claim 1 or 2, (Item 4) The acquisition means uses the information indicating that the other communication device will disable communication using the second communication method as the identification information used to identify whether the other communication device is in a state where it can perform communication using the second communication method. 3. The communication device according to claim 1 or 2, (Item 5) The control means disables communication using the second communication method in the communication device based on the determination that a predetermined percentage or more of the other communication devices connected to the communication device are not in a state where communication using the second communication method can be performed. 5. The communication device according to any one of items 1 to 4, (Item 6) The control means enables communication using the second communication method in the communication device based on the fact that a predetermined percentage or more of the other communication devices connected to the communication device are in a state where communication using the second communication method can be performed. 5. The communication device according to any one of items 1 to 4, (Item 7) The communication device further includes a notification unit that notifies the communication device that the control unit has enabled or disabled communication using the second communication method. 7. The communication device according to any one of items 1 to 6, (Item 8) When it is determined that the communication device has disabled communication using the second communication method and that the other communication device newly connected to the communication device is in a state in which communication using the second communication method can be performed, the control means enables communication using the second communication method in the communication device; The notification means notifies the other communication device that the control means has enabled communication using the second communication method in the communication device. 8. The communication device according to item 7, (Item 9) The notification means performs the notification using an Association Response frame. 9. The communication device according to item 8, (Item 10) When it is determined that the communication device has disabled communication using the second communication method and that the other communication device connected to the communication device has enabled communication using the second communication method, the control means enables communication using the second communication method in the communication device; The notification means notifies the other communication device that the control means has enabled communication using the second communication method in the communication device. 8. The communication device according to item 7, (Item 11) The notification means sends the notification to the other communication device using an Action frame or a frame responding to an Action frame received from the other communication device. 11. The communication device according to item 10. (Item 12) When the communication device enables communication using the second communication method and it is determined that a predetermined percentage or more of the other communication devices connected to the communication device disable communication using the second communication method, the control means disables communication using the second communication method in the communication device; The notification means notifies the other communication device that the control means has disabled communication using the second communication method in the communication device. 8. The communication device according to item 7, (Item 13) The notification means sends the notification to the other communication device using a Beacon frame or a Probe Response frame. 11. The communication device according to item 10. (Item 14) 1. A control method executed by a communication device that communicates with one or more other communication devices using wireless frames that comply with at least one standard included in the IEEE 802.11 series of standards, comprising: a communication step of performing communication using a plurality of communication methods, including a first communication method configured to be able to communicate by bonding a first channel and one or more second channels different from the first channel, the first communication method acquiring a transmission right using the first channel to perform communication, and a second communication method acquiring a transmission right using a third channel included in the second channels to perform communication using at least the third channel when the first channel cannot be used; an acquisition step of acquiring, from each of the other communication devices connected to the communication device, identification information used to identify whether the other communication devices are in a state where they can perform communication using the second communication method; a control step of enabling or disabling communication using the second communication method in the communication device based on whether the other communication device connected to the communication device is in a state where communication using the second communication method can be performed. A control method comprising: (Item 15) 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 13.

[0089] The 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. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0090] 101:AP, 102:STA, 10:Network, 111:AP, 112:STA, 11:Network

Claims

1. A communication device that communicates with one or more other communication devices using wireless frames that comply with at least one standard included in the IEEE 802.11 series of standards, a communication means for performing communication using a plurality of communication methods, including a first communication method configured to be able to communicate by bonding a first channel with one or more second channels different from the first channel, the first communication method acquiring a transmission right using the first channel to perform communication, and a second communication method acquiring a transmission right using a third channel included in the second channels to perform communication using at least the third channel when the first channel cannot be used; an acquisition means for acquiring, from each of the other communication devices connected to the communication device, identification information used to identify whether the other communication devices are in a state where they can perform communication using the second communication method; and a control means for enabling or disabling communication using the second communication method in the communication device based on whether the other communication device connected to the communication device is in a state where communication using the second communication method can be performed. A communication device comprising:

2. The acquisition means uses the information indicating whether the other communication device has the ability to perform communication using the second communication method as the identification information used to identify whether the other communication device is in a state where it can perform communication using the second communication method.

2. The communication device according to claim 1.

3. The acquisition means uses the information indicating that the other communication device enables communication using the second communication method as the identification information used to identify whether the other communication device is in a state where it can perform communication using the second communication method.

3. The communication device according to claim 1 or 2.

4. The acquisition means uses the information indicating that the other communication device will disable communication using the second communication method as the identification information used to identify whether the other communication device is in a state where it can perform communication using the second communication method.

3. The communication device according to claim 1 or 2.

5. The control means disables communication using the second communication method in the communication device based on the determination that a predetermined percentage or more of the other communication devices connected to the communication device are not in a state where communication using the second communication method can be performed.

2. The communication device according to claim 1.

6. The control means enables communication using the second communication method in the communication device based on the fact that a predetermined percentage or more of the other communication devices connected to the communication device are in a state where communication using the second communication method can be performed.

2. The communication device according to claim 1.

7. The communication device further includes a notification unit that notifies the communication device that the control unit has enabled or disabled communication using the second communication method.

2. The communication device according to claim 1.

8. When it is determined that the communication device has disabled communication using the second communication method and that the other communication device newly connected to the communication device is in a state in which communication using the second communication method can be performed, the control means enables communication using the second communication method in the communication device; The notification means notifies the other communication device that the control means has enabled communication using the second communication method in the communication device.

8. The communication device according to claim 7,

9. The notification means performs the notification using an Association Response frame.

9. The communication device according to claim 8.

10. When it is determined that the communication device has disabled communication using the second communication method and that the other communication device connected to the communication device has enabled communication using the second communication method, the control means enables communication using the second communication method in the communication device; The notification means notifies the other communication device that the control means has enabled communication using the second communication method in the communication device.

8. The communication device according to claim 7,

11. The notification means sends the notification to the other communication device using an Action frame or a frame responding to an Action frame received from the other communication device.

11. The communication device according to claim 10.

12. When the communication device enables communication using the second communication method and it is determined that a predetermined percentage or more of the other communication devices connected to the communication device disable communication using the second communication method, the control means disables communication using the second communication method in the communication device; The notification means notifies the other communication device that the control means has disabled communication using the second communication method in the communication device.

8. The communication device according to claim 7,

13. The notification means sends the notification to the other communication device using a Beacon frame or a Probe Response frame.

11. The communication device according to claim 10.

14. 1. A control method executed by a communication device that communicates with one or more other communication devices using wireless frames that comply with at least one standard included in the IEEE 802.11 series of standards, comprising: a communication step of performing communication using a plurality of communication methods, including a first communication method configured to be able to communicate by bonding a first channel and one or more second channels different from the first channel, the first communication method acquiring a transmission right using the first channel to perform communication, and a second communication method acquiring a transmission right using a third channel included in the second channels to perform communication using at least the third channel when the first channel cannot be used; an acquisition step of acquiring, from each of the other communication devices connected to the communication device, identification information used to identify whether the other communication devices are in a state where they can perform communication using the second communication method; a control step of enabling or disabling communication using the second communication method in the communication device based on whether the other communication device connected to the communication device is in a state where communication using the second communication method can be performed. A control method comprising:

15. A program for causing a computer to function as each of the means included in the communication device according to claim 1.

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