Communication apparatus, control method, and storage medium

Abstract

To provide an apparatus and a method for improving utilization efficiency of a channel of a communication link.SOLUTION: A communication device AP that communicates with another communication device STA using a wireless frame conforming to the IEEE802.11 standard is configured to be communicable by bonding a first channel and one or more second channels different from the first channel, performing communication using a plurality of communication schemes including a first communication scheme for performing communication by acquiring a transmission right using a first channel and a second communication scheme for performing communication by acquiring a transmission right using a third channel included in a second channel when the first channel cannot be used, and determining a third channel from among second channels based on a value shared with another communication device in a BSS configured by the communication device; The other communication device is notified of identification information used for identifying the third channel.SELECTED DRAWING: Figure 7

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

[0006] A communication device according to one embodiment of the present invention is a communication device that communicates with other communication devices using wireless frames that comply with at least one standard included in the IEEE 802.11 standard series, and has a communication means that communicates 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 that, when the first channel cannot be used, acquires a transmission right using a third channel included in the second channel and communicates using at least the third channel; a determination means that determines the third channel from among the second channels based on a value shared with the other communication devices in a Basic Service Set (BSS) configured by the communication device; and a notification means that notifies the other communication devices of specific information used by the other communication devices to identify the third channel. [Effects of the Invention]

[0007] According to the present invention, frequency resources can be used more efficiently in a communication system that uses a communication link consisting 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. 10 is a diagram illustrating an example of a sequence when a communication device communicates data. [Figure 4] FIG. 2 illustrates an example of a hardware configuration of a communication device. [Figure 5] FIG. 2 is a diagram illustrating an example of a functional configuration of an AP. [Figure 6] FIG. 10 is a diagram illustrating an example of the functional configuration of an STA. [Figure 7] FIG. 10 is a diagram illustrating an example of a sequence executed between an AP and a STA. [Figure 8] FIG. 10 is a diagram illustrating an example of a processing flow executed when a communication device communicates data. [Figure 9] FIG. 10 is a diagram illustrating an example of a sequence when a communication device communicates data. [Figure 10] FIG. 10 is a diagram illustrating an example of a processing flow executed when an AP determines a communication method with a STA. [Figure 11] FIG. 10 is a diagram illustrating an example of a processing flow executed when a STA determines a communication method with an AP. [Figure 12] FIG. 10 is a diagram illustrating an example of a processing flow executed when a communication device communicates data. 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 a station (STA) 102. The AP 101 and the STA 102 are communication devices capable of performing wireless communication in accordance with the IEEE 802.11 series of standards. IEEE stands for Institute of Electrical and Electronics Engineers. FIG. 1 shows a configuration in which the STA 102 participates in a network 103 established by the AP 101. The network 103 may also be referred to as a Basic Service Set (BSS). Although the network 103 in FIG. 1 shows a configuration in which one AP 101 and one STA 102 exist, multiple APs and multiple STAs may exist. Furthermore, multiple STAs may be connected to one AP, and one STA may be connected to multiple APs. Note that in FIG. 1, a network 113 formed by an AP 111 and a STA 112 exists near the network 103 formed by the AP 101 and the STA 102. Further, near the networks 103 and 113, there is a network 123 configured by an AP 121 and a STA 122. Like the AP 101 and the STA 102, the AP 111, the AP 121, the STA 112, and the STA 122 are communication devices capable of performing wireless communication in accordance with the IEEE 802.11 series standard. For the AP 101 and the STA 102, the network 103 is a BSS to which the respective devices connect, and may be referred to as their own BSS. On the other hand, for the AP 101 and the STA 102, the network 113 and the network 123 are networks that may cause interference with the respective BSSs, and may be referred to as overlapping BSSs (OBSSs). In this embodiment, the AP 101, the AP 111, the AP 113, the STA 102, the STA 112, and the STA 113 may be collectively referred to as the communication device 100. The following description will be given for AP 101 and STA 102, but the same description can also be applied to AP 111, AP 121, STA 112, and STA 122.

[0011] In this embodiment, the AP 101 and the STA 102 are 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 that 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 stands for PLCP Protocol Data Unit, and PLCP stands for Physical Layer Convergence Protocol. Note that names such as UHR and IEEE 802.11bn may be changed to different names when the standard is fully established. It should be noted that this specification and the claims appended hereto are applicable to communication devices using all successor standards to IEEE 802.11be. The communication device 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 STA 102 may be, for example, but is not limited to, a camera, a tablet, a smartphone, a PC, a mobile phone, a video camera, a headset, etc. The STA 102 may be an information processing device such as a wireless chip capable of performing wireless communication in accordance with the IEEE802.11bn standard or the like.

[0012] 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 series of standards specifies a frequency channel using a 20 MHz bandwidth as the basic channel in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands. The standards also define 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] 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.

[0014] For example, when communicating using a link with a bandwidth of 160 MHz, the communication device 100 may determine whether or not to transmit using only the Primary Channel (PCH) with a bandwidth of 20 MHz included in that link. For example, the IEEE 802.11 series of standards state 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. That is, 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 the PIFS period immediately before the start of transmission, the communication device 100 may perform transmission using channel bonding using the idle channel and the PCH. PIFS is an abbreviation for Priority Interframe Space. Furthermore, when communication device 100 determines that transmission is not possible as a result of 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 a single link may be called a secondary channel (SCH). A secondary channel may also be called a non-primary channel (NPCH).

[0015] 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 out 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 standards provide 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.

[0016] However, not using other idle channels (NPCHs) based on the PCH being busy can hinder efficient use of frequency resources across the link. FIG. 2A shows an example of a time chart when STA 102 transmits data to AP 101. In FIG. 2A, 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, for example, 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 STA 102 transmits data to AP 101. In FIG. 2B, while STA 102 is performing carrier sensing on the PCH, the PCH is being used in other networks (e.g., network 113 and network 123 in FIG. 1) located geographically close to STA 102. In this case, the PCH is determined to be busy by carrier sensing by STA 102, and therefore STA 102 is not permitted to communicate with AP 101 using the NPCH, even if, for example, the seven NPCHs other than the PCH are idle. However, because AP 101 is not transmitting at this time, 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, the PCH with a bandwidth of 20 MHz is used by another network, the remaining 140 MHz of idle NPCH is not used, and frequency resources cannot be used efficiently.

[0017] 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). When the communication device 100 determines that the PCH is being used by a communication device of another network, it subsequently determines whether transmission is possible on the SPCH. When the communication device 100 determines that transmission is possible on the SPCH, it performs transmission using one or more NPCHs including the SPCH. In this embodiment, a communication method for transmitting 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. 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 a first channel (PCH), it communicates using a first communication method configured to enable communication by bonding the first channel with one or more second channels (NPCH) different from the first channel. That is, in the first communication method, the communication device 100 may use only the PCH without using the NPCH. 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 communicates using a second communication method using at least the third channel. The certain additional conditions may be, for example, that the PCH is used by the OBSS and the SPCH is not used.By configuring communication using multiple communication methods including these, communication device 100 can communicate efficiently by using NPCH, which has little impact on PCH, even when PCH is in use.

[0018] Here, NPCA may not be performed efficiently depending on the channel selected as the SPCH in each network. For example, assume that in network 103, the NPCH adjacent to the PCH is set as the SPCH. At this time, when communication using the PCH is started in network 113 as an OBSS and channel bonding including the PCH and SPCH in network 103 is performed in this communication, both the PCH and the SPCH become busy. In this case, AP 101 and STA 102 constituting network 103 cannot perform NPCA even if there are channels available for the NPCH other than the PCH and SPCH. Furthermore, NPCA may not be performed efficiently when multiple networks exist near a network. For example, as shown in FIG. 1, assume that networks 113 and 123 exist near network 103, and the PCH and SPCH in each network are the same. At this time, as shown in FIG. 3, when communication using the PCH (e.g., communication from AP 111 to STA 112) is started in network 113, the PCH enters a busy state 301. In this case, AP 101 and STA 102 set NAV 302 in the PCH. Subsequently, NPCH access using the same SPCH may be attempted in networks 103 and 123. For example, in the first SPCH in FIG. 3, if communication in network 123 (e.g., communication from AP 121 to STA 122) starts before communication in network 103, the first SPCH enters a busy state 303. If only one SPCH is set in network 103, the busy state of the first SPCH causes AP 101 and STA 102 constituting network 103 to wait until the NAV of the PCH ends without transmitting. In this case, for example, if the channels used by networks 113 and 123 are part of the frequency band available to network 103, the remaining frequency band will not be used efficiently.For example, in FIG. 2B, if network 113 uses the PCH and network 123 uses 20 MHz of the NPCH, the remaining 120 MHz frequency band may go unused. Also, if multiple SPCHs are configured in network 103, AP 101 or STA 111 may attempt NPCH access in the SPCH with the next highest priority (nth). In FIG. 3, after successful NPCH access using the nth SPCH, STA 102 sets TXOP 304, transmits a data frame 305, and receives a Block ACK 306. TXOP is an abbreviation for Transmission Opportunity. In this case, a transmission delay occurs from the time STA 102 attempts channel access in the PCH until successful channel access in the nth SPCH.

[0019] In consideration of these circumstances, the communication device 100 in this embodiment performs NPCH access using an SPCH determined based on a value commonly used in its own BSS. For example, the AP 101 determines a third channel (SPCH) from among the second channels (NPCH) based on a value shared in its own BSS, and notifies STAs connected to its own BSS of identification information used to identify the third channel. Furthermore, the STA 102 receives identification information identifying the third channel determined from among the second channels based on a value shared in the BSS to which the device connects. The value shared in the BSS may be, for example, a random number acquired by the AP 101. The value shared in the BSS may be a value based on at least a portion of a BSS Color used in the BSS. The BSS Color is an identifier used to identify the own BSS. The value shared in the BSS may be a value based on at least a portion of the MAC address of the AP 101. The value shared in the BSS may be a value based on at least a part of the time information included in the Beacon frame transmitted immediately before the AP 101 determines the third channel. This configuration allows NPCH access using a common SPCH in the BSS, while enabling the selection of an SPCH different from the SPCH used in the OBSS. The AP 101 may notify the STA 102 of information indicating the determined SPCH as identification information, or may notify the STA 102 of information used to determine the SPCH as identification information. A configuration example and a processing example of the communication device 100 that operates in this manner will be described below.

[0020] (Device configuration) 4 shows an example of the hardware configuration of the communication device 100 (AP 101, STA 102, etc.) according to this embodiment. As an example of the hardware configuration, the communication device 100 has, for example, a storage unit 401, a control unit 402, a function unit 403, an input unit 404, an output unit 405, a communication unit 406, and an antenna 407. The communication device 100 may have multiple antennas.

[0021] The storage unit 401 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, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, non-volatile memory card, DVD, etc.

[0022] The control unit 402 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 401. The control unit 402 may control the entire communication device 100 in cooperation with the control program stored in the storage unit 401 and an OS (Operating System). The CPU and MPU are abbreviations for Central Processing Unit and Micro Processing Unit, respectively. When the control unit 402 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.

[0023] Furthermore, the control unit 402 controls the functional unit 403 to execute predetermined processes such as communication, image capture, printing, and projection. The functional unit 403 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 403 is an image capture unit that performs image capture processing. Also, for example, if the device is a printer, the functional unit 403 is a print unit that performs print processing. Also, for example, if the device is a projector, the functional unit 403 is a projection unit that performs projection processing.

[0024] The input unit 404 receives various operations from the user. The output unit 405 outputs various types of information to the user via a monitor screen or a speaker. The output from the output unit 405 may be a display on a monitor screen, an audio output from a speaker, a vibration output, or the like. The input unit 404 and the output unit 405 may both be implemented as a single module, such as a touch panel. The input unit 404 and the output unit 405 may be integrated with the communication device 100 or may be separate devices.

[0025] The communication unit 406 controls wireless communication compliant with the IEEE 802.11bn standard. The communication unit 406 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 406 controls the antenna 407 to transmit and receive signals for wireless communication generated by the control unit 402. The communication unit 406 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 406 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 406. The antenna 407 may be configured as a separate unit from the communication unit 406, or may be configured as a single module together with the communication unit 406. When the communication device 100 is configured to simultaneously perform carrier sensing of a plurality of SPCHs, the communication device 100 may include as many communication units 406 as necessary for that purpose.

[0026] Antenna 407 is an antenna capable of communication in, for example, the 2.4 GHz band, the 5 GHz band, the 6 GHz band, millimeter waves, etc. Although Fig. 4 shows a configuration in which communication device 100 has two antennas 407, communication device 100 may have one or three or more antennas, or may have 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 406 for each antenna.

[0027] (Functional configuration) 5 shows an example of the functional configuration of AP 101. 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. AP 101 includes a wireless communication control unit 501, an SPCH determination unit 502, an information notification unit 503, and an information update unit 504.

[0028] The wireless communication control unit 501 communicates with other communication devices using the communication unit 406. For example, the wireless communication control unit 501 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 501 communicates using the first communication method. On the other hand, when the PCH is busy, the wireless communication control unit 501 determines whether a predetermined condition is satisfied, and, if the predetermined condition is satisfied, communicates using the second communication method. When communicating using the second communication method, the wireless communication control unit 501 performs NPCH access using the SPCH identified by the SPCH determination unit 502.

[0029] The SPCH determination unit 502 determines an SPCH to be used when performing NPCH access in its own BSS. For example, the SPCH determination unit 502 determines an SPCH from among NPCHs based on a value shared in its own BSS. As an example, the SPCH determination unit 502 can determine an SPCH using a random number acquired by the AP 101, a BSS Color, the MAC address of the AP 101, time information included in a Beacon transmitted by the AP 101, and the like.

[0030] The information notification unit 503 notifies the STA of specific information used for identifying an SPCH to be used for NPCH access in the own BSS. For example, the information notification unit 503 can notify, as the specific information, information indicating the SPCH determined by the SPCH determination unit 502. Furthermore, when a method for determining an SPCH from NPCHs is shared between the information notification unit 503 and the STA 102, the information notification unit 503 can notify, as the specific information, information used for determining an SPCH.

[0031] The information updating unit 504 updates the information indicating the SPCH and the information used to determine the SPCH over time. For example, the information updating unit 504 may update the information indicating the SPCH and the information used to determine the SPCH periodically or when an event occurs. The information updated by the information updating unit 504 may be used by the SPCH determination unit 502 to determine the SPCH. Furthermore, the information updated by the information updating unit 504 may be notified to the STA 102 by the information notification unit 503.

[0032] 6 shows an example of the functional configuration of the STA 102. The functional configuration in this embodiment is an example of a functional configuration realized, for example, by one or more processors executing programs stored in one or more memories. The STA 102 includes a wireless communication control unit 601, an information receiving unit 602, an SPCH identification unit 603, and an information updating unit 604.

[0033] The wireless communication control unit 601 communicates with other communication devices using the communication unit 406. For example, the wireless communication control unit 601 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 601 communicates using the first communication method. On the other hand, when the PCH is busy, the wireless communication control unit 601 determines whether a predetermined condition is met, and, if the predetermined condition is met, communicates using the second communication method. When communicating using the second communication method, the wireless communication control unit 601 performs NPCH access using the SPCH identified by the SPCH identification unit 603.

[0034] The information receiving unit 602 receives identification information used to identify an SPCH to be used when performing NPCH access in the BSS to which the device is connected. The information receiving unit 602 may receive, for example, information indicating an SPCH determined by the AP 101 as the identification information. Furthermore, if a method for determining an SPCH from NPCHs is shared with the AP 101, the information receiving unit 602 may receive, as the identification information, information used to determine an SPCH. For example, the information receiving unit 602 may receive a random number acquired by the AP 101, a BSS Color, the MAC address of the AP 101, time information included in a Beacon transmitted by the AP 101, etc.

[0035] The SPCH identification unit 603 identifies an SPCH to be used when performing NPCH access in the BSS to which the device is connected. For example, the SPCH identification unit 603 identifies an SPCH from among NPCHs based on a value shared in the BSS to which the device is connected. As an example, the SPCH identification unit 603 may identify an SPCH based on information indicating an SPCH determined by the AP 101 received by the information receiving unit 602. The SPCH identification unit 603 may also determine an SPCH using a random number acquired by the AP 101 received by the information receiving unit 602, a BSS Color, the MAC address of the AP 101, time information included in a Beacon transmitted by the AP 101, and the like.

[0036] The information update unit 604 updates the SPCH over time. For example, the information update unit 604 may update the SPCH periodically or when an event occurs. The information update unit 604 may update the SPCH based on information received by the information receiving unit 602 from the AP 101.

[0037] (Example of processing executed by AP101 and STA102) Hereinafter, some examples of the flow of processing executed by the AP 101 and the STA 102 in this embodiment will be described.

[0038] (Processing when sharing SPCH between AP and STA) The following describes the flow of processing executed when an SPCH to be used for NPCH access is determined in a BSS provided by the AP 101 and shared with the STA 102. FIG. 7 shows an example sequence of processing executed when an SPCH is determined by the AP 101 and shared with the STA 102. First, when the AP 101 is powered on and started up, it starts setting up the BSS configured by the AP 101 (its own BSS). For example, the AP 101 may read communication parameters to be used in its own BSS from the storage unit 401. The AP 101 starts operation of its own BSS using the read communication parameters. When communication using NPCH access is enabled in its own BSS, the AP 101 may determine an SPCH to be used for NPCH access before starting operation of the BSS (F701). An example of processing executed by the AP 101 when determining an SPCH will be described later. When the AP 101 starts operation of its own BSS, it periodically transmits Beacon frames (F702). The AP 101 broadcasts communication parameters used in its own BSS in a Beacon frame. For example, the AP 101 may use a Beacon frame to broadcast that its own device is capable of performing NPCH access. The AP 101 may also use a Beacon frame to broadcast specific information that enables a STA connected to its own BSS to identify the SPCH to be used when performing NPCH access in its own BSS.

[0039] When the STA 102 detects the presence of the AP 101 by receiving the Beacon frame, it transmits a Probe Request frame addressed to the AP 101 (F703). The STA 102 may use the Probe Request frame to notify the AP 101 that it is capable of performing NPCH access. The STA 102 may also use the Probe Request frame to notify the AP 101 whether it is capable of identifying an SPCH based on identification information acquired from the AP 101. This enables the AP 101 to determine whether to perform NPCH access with the STA 102, or whether to determine the SPCH using information about its own BSS when performing NPCH access. In response to receiving the Probe Request frame, the AP 101 transmits a Probe Response frame addressed to the STA 102. The AP 101 may use the Probe Response frame to notify the STA 102 that it is capable of performing NPCH access and / or identification information that can identify the SPCH to be used when performing NPCH access in its own BSS. Upon receiving the Probe Response frame, the STA 102 performs connection processing with the AP 101 (F705). For example, the STA 102 performs connection processing by executing authentication processing and association processing. The authentication processing can be performed, for example, by the AP 101 and the STA 102 exchanging Authentication frames. The association processing can be performed, for example, by the STA 102 transmitting an Association Request frame addressed to the AP 101 and the AP 101 transmitting an Association Response frame addressed to the STA 102. Note that, during the association processing, the AP 101 and the STA 102 can share specific information that indicates that their own devices are capable of performing NPCH access and that can identify the SPCH to be used when performing NPCH access in their own BSS. Completion of the association processing establishes connection between the AP 101 and the STA 102. Hereinafter, the BSS to which the STA 102 is connected may be referred to as the own BSS.

[0040] The STA 102 identifies an SPCH based on the information received from the AP 101 (F706). For example, the STA 102 can identify an SPCH based on identification information received from the AP 101 that can identify an SPCH to be used when performing NPCH access in its own BSS. An example of the process performed by the STA 102 to identify an SPCH based on the identification information received from the AP 101 will be described later.

[0041] When performing data communication with a communication device of the other party, each of the AP 101 and the STA 102 uses a first communication method configured to enable communication by bonding one or more of a PCH and an NPCH, or a second communication method using at least an SPCH (F707). When performing communication using the second communication method (NPCH access), the AP 101 performs carrier sense using the SPCH determined in F701. Furthermore, when performing communication using NPCH access, the STA 102 performs carrier sense using the SPCH identified in F706. In this way, when performing NPCH access, each of the AP 101 and the STA 102 uses the SPCH determined by the AP 101, so that the AP 101 and the STA 102 can communicate using the same SPCH. Furthermore, when the AP 101 determines the SPCH after starting up its own device, each AP can select a different SPCH, which allows efficient communication using the NPCH.

[0042] (Example of operation when AP determines SPCH) The process by which the AP 101 determines the SPCH will be described. First, the AP 101 determines the frequency band to be used for communication by the AP 101. For example, the AP 101 may select a frequency to be used for communication from among available frequencies in frequency bands such as 2.4 GHz, 5 GHz, and 6 GHz. The AP 101 may also determine the frequency bandwidth to be used for communication from among bandwidths such as 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz. The AP 101 may also select a frequency or bandwidth other than these. The AP 101 determines the PCH and SPCH in a frequency band determined by a combination of the frequency and frequency bandwidth to be used for communication by the AP 101. For example, if the AP 101 selects an 80 MHz bandwidth for a given frequency, it selects one of four 20 MHz frequency channels included in the 80 MHz bandwidth as the PCH. Then, the AP 101 selects one of the other frequency channels (i.e., NPCH) included in that frequency band as the SPCH. Assume that four 20 MHz frequency channels included in an 80 MHz bandwidth are designated as frequency channels 0 to 3, and frequency channel 0 is determined as the PCH. In this case, the AP 101 may use a random number to determine the SPCH from among frequency channels 1 to 3 (first determination method). For example, the AP 101 may input a predetermined seed into a random number generator that outputs an integer between 1 and 3 and determine the SPCH based on the output random number. As an example, the AP 101 may determine to use the first frequency channel when the random number is 1, the second frequency channel when the random number is 2, and the third frequency channel when the random number is 3 as the SPCH. The random number generator used to determine the SPCH is not limited to the above, and it is sufficient that each of the random numbers or ranges of random numbers output by the random number generator is associated with each of the frequency channels that are candidates for the SPCH. For example, for a random number generator that generates values ​​between 0 and 1 (rounded up to the third decimal place), values ​​in the range of 0 to 0.33, values ​​in the range of 0.34 to 0.66, and values ​​in the range of 0.67 to 1 may be associated with the first to third frequency channels, respectively.In this way, the AP 101 determines the SPCH based on a random number, so that different SPCHs are used among the APs.

[0043] If the AP 101 selects a 160 MHz bandwidth, the 160 MHz bandwidth may include eight 20 MHz frequency channels. In this case, the AP 101 may select one of the 20 MHz frequency channels as the PCH and select an SPCH from the remaining seven 20 MHz frequency channels. If the AP 101 selects a 320 MHz bandwidth, the 320 MHz bandwidth may include 16 20 MHz frequency channels. In this case, the AP 101 may select one of the 20 MHz frequency channels as the PCH and select an SPCH from the remaining 15 20 MHz frequency channels. In a similar manner, the AP 101 may select a PCH and an SPCH for various bandwidths available to the AP 101.

[0044] The AP 101 may determine the SPCH using communication parameters unique to its own BSS. By determining the SPCH using communication parameters unique to its own BSS, the SPCH used in each BSS may differ. For example, the AP 101 may determine the SPCH using the BSS Color used in its own BSS (second determination method). The BSS Color is an identifier for distinguishing the own BSS from the OBSS, and using this identifier may result in selecting a different SPCH between the own BSS and the OBSS. As an example, the AP 101 may determine the SPCH based on the remainder obtained when a value indicating the BSS Color of the own BSS is divided by the number of NPCHs that are candidates for the SPCH. When the BSS Color is expressed in 6 bits, the value indicating the BSS Color is 1 to 63. As in the above example, when the AP 101 uses an 80 MHz bandwidth, the number of NPCHs that are candidates for the SPCH may be three. In this case, when the value indicating the BSS Color is divided by 3, the remainders 0, 1, and 2 are associated with the first to third frequency channels, respectively. For example, if the value indicating the BSS Color used by the AP 101 is 10, the remainder is 1, and therefore the AP 101 determines the second frequency channel as the SPCH. In this way, the AP 101 can determine the SPCH using the BSS Color used in its own BSS. Note that some of the six bits indicating the BSS Color may be used to determine the SPCH. For example, the SPCH may be determined by the above-described modulo operation using two of the six bits.

[0045] The AP 101 may determine the SPCH using its own MAC address (third determination method). Because a MAC address is an identifier that uniquely identifies each device, using this identifier may allow the AP 101 to select a different SPCH between itself and the BSS. As an example, the AP 101 may determine the SPCH based on the remainder obtained when converting its own MAC address to a numerical value and dividing that numerical value by the number of NPCHs that are candidates for the SPCH. For example, if the MAC address is a 48-bit string, the converted numerical value may be obtained by interpreting the 48-bit string as a decimal number. Alternatively, if the MAC address is expressed as six octets, the converted numerical value may be obtained by interpreting each octet as a decimal number and calculating the sum or product of the six numerical values ​​obtained. Note that a portion of the 48 bits or six octets representing the MAC address may be used to determine the SPCH. For example, as described above for BSS Color, a portion of the bits or octets may be used to determine the SPCH using the above-described modulo operation. If a randomly changed random MAC address is used as the MAC address of the AP 101, the AP 101 may determine the SPCH using the random MAC address. If the random MAC address is updated, the AP 101 may execute a process for updating the SPCH in response to the update of the random MAC address.

[0046] The AP 101 may determine the SPCH using its own time information (fourth determination method). The AP 101 may have a time synchronization function for synchronizing time with communication devices connected to its own BSS. For example, the AP 101 may determine the SPCH using time information stored for the time synchronization function. In this case, the SPCH may change over time. For example, if a modular arithmetic operation is performed using time information, as in the case of determining the SPCH based on the BSS Color or the MAC address of the AP, the result of the modular arithmetic operation also changes over time. As a result, the determined SPCH also changes. In this way, if the SPCH changes over time, even if the same SPCH as another BSS is temporarily used, a different SPCH will be used over time, which may enable more efficient communication. The AP 101 may determine the SPCH using part of the time information. For example, the AP 101 may select the part of the time information (hour, minute, second) to use based on the period for changing the SPCH. For example, if the AP 101 wants to increase the interval for changing the SPCH, it may use the information corresponding to the hour in the time information, and if the AP 101 wants to decrease the interval for changing the SPCH, it may use the information corresponding to the second in the time information. The AP 101 may determine the SPCH by performing the above-mentioned modulo operation on the time information to be used.

[0047] The AP 101 may determine the SPCH using a process other than modular arithmetic. For example, the AP 101 may determine the SPCH using a random number obtained by inputting communication parameters such as the BSS Color, the MAC address of the AP itself, and time information as seeds into a random number generator (fifth determination method). This may result in different SPCHs being used in each BSS even if the same communication parameters (BSS Color, etc.) are used between the BSSs. In this case, as described above, the AP 101 may determine one SPCH based on the obtained random number by associating the value or range of values ​​output by the random number generator with SPCH candidates.

[0048] The AP 101 may also determine the SPCH by combining the above-mentioned communication parameters and processes. For example, the AP 101 may perform a modulo operation on the sum of a value indicating the BSS Color used in its own BSS and a value generated based on time information. This allows different SPCHs to be used between BSSs, and even if the same SPCH is used temporarily, different SPCHs will be used over time. Furthermore, when determining the SPCH using part of the bits or octets indicating the BSS Color of its own BSS or its own device's MAC address, the AP 101 may periodically change the location of the bits or octets to be used. This allows different SPCHs to be used over time, even if the same SPCH is used temporarily between multiple BSSs. In this case, the AP 101 may input a value based on other communication parameters used in its own BSS as a seed into a random number generator and output the random number. For example, the AP 101 normalizes the range of random numbers generated by the random number generator based on the number of bits or octets of the BSS Color or MAC address. The SPCH is then determined using the BSS Color or MAC address bit or octet that corresponds to the output random number. For example, if the output random number is 4, the rightmost or leftmost four bits of the BSS Color are used to determine the SPCH. The information and process used by AP 101 to determine the SPCH are not limited to those described above, and any information or process that allows different SPCHs to be determined between BSSs may be used.

[0049] (Processing example 1 when STA identifies SPCH) The AP 101 notifies its own BSS of the SPCH determined as described above. For example, the AP 101 performs the notification using a Beacon frame. In this case, the AP 101 may include information that enables the STA 102 to identify the SPCH in an information element, field, subfield, or the like related to NPCH access included in the Beacon frame. The information that enables the STA 102 to identify the SPCH may be, for example, information indicating a channel number corresponding to the SPCH. The information that enables the SPCH to be identified may also be, for example, information indicating a frequency band or center frequency of a channel corresponding to the SPCH. When each STA connected to its own BSS receives a Beacon frame including information indicating the SPCH, the SPCH to be used by each STA can be updated even if the SPCH is changed periodically. Note that if the SPCH is set statically and is not changed, the AP 101 may notify the STA 102 of the SPCH when connecting to the STA 102. In this case, the SPCH may be notified using a Probe Response frame, an Association frame, or the like. When the AP 101 uses a different SPCH for each STA connected to its own BSS, the AP 101 can notify the STA of the SPCH individually using an Action frame or the like.

[0050] The STA 102 identifies the SPCH based on information capable of identifying the SPCH notified by the AP 101. For example, the STA 102 receives a Beacon frame and can identify the SPCH using information elements, fields, subfields, etc. related to NPCH access that are included in the received Beacon frame. For example, if the information capable of identifying the SPCH includes information that directly indicates the SPCH, such as information indicating a channel number corresponding to the SPCH or information indicating the frequency band or center frequency of the channel corresponding to the SPCH, the STA 102 can identify the SPCH from these.

[0051] (Processing example 2 when STA identifies SPCH) In the above-described processing example 1 when the STA identifies an SPCH, information indicating the SPCH is directly notified as identification information that enables the STA 102 to identify the SPCH determined by the AP 101, and the STA 102 identifies the SPCH from this information. Below, an example is described in which the STA 102 receives information for determining the SPCH from the AP 101 and determines the SPCH based on the received information. That is, below, an example is described in which the STA 102 shares a method for determining an SPCH from an NPCH with the AP 101.

[0052] For example, when the AP 101 determines the SPCH using a first determination method using a random number, the AP 101 notifies the STA 102 of information indicating the value of the predetermined seed used when determining the SPCH. In this case, the STA 102 has the same random number generator as the one used by the AP 101 to generate the random number, and acquires the random number by using the received predetermined seed as input to the random number generator. The STA 102 then determines the frequency channel (NPCH) associated with the acquired random number as the SPCH. The random number generator may be provided by the AP 101 when establishing a connection with the AP 101, or may be stored in the STA 102 in advance. In this case, the random number generator may be a pseudo-random number generation function.

[0053] For example, when the AP 101 determines the SPCH using the second determination method using the BSS Color of the own BSS, the STA 102 may determine the SPCH using a value in a BSS Color field or the like included in a Beacon frame, etc. For example, the STA 102 may determine, as the SPCH, the NPCH associated with the remainder obtained by performing a modular arithmetic operation using the received value indicating the BSS Color of the own BSS.

[0054] For example, if the AP 101 determines the SPCH using the third determination method using its own MAC address, the STA 102 may determine the SPCH using a value based on the MAC address of the AP 101, such as a BSSID included in a Beacon frame or the like. The method for converting the MAC address of the AP 101 into a numerical value may be shared when the STA 102 connects to the AP 101, or may be set in advance in the STA 102. Note that if a random MAC address that is randomly changed is used as the MAC address of the AP 101, the STA 102 may execute processing to update the SPCH in response to an update of the random MAC address.

[0055] When the AP 101 determines the SPCH using, for example, the fourth determination method using time information, the STA 102 may determine the SPCH using time information such as a timestamp included in a Beacon frame, etc. When a portion of the timestamp is used, the STA 102 may obtain the portion of the timestamp to be used to determine the SPCH when connecting to the AP 101, or the portion may be set in advance in the STA 102.

[0056] For example, if the AP 101 determines the SPCH using the fifth determination method that uses a random number obtained by inputting communication parameters as a seed into a random number generator, the STA 102 may first acquire the communication parameters in the same manner as the second to fourth determination methods. The STA 102 may acquire the communication parameters using, for example, a Beacon frame. The STA 102 may input the acquired communication parameters as a seed into a pseudo-random number generation function to acquire a random number, and may determine the NPCH associated with the acquired random number as the SPCH.

[0057] When the AP 101 determines the SPCH by, for example, combining the above-mentioned communication parameters and processes, the STA 102 can determine the SPCH by using the communication parameters and processes used by the AP 101. Note that the STA 102 may specify the combination of communication parameters and processes used to determine the SPCH when connecting with the AP 101, or may specify the combination by having it set in advance in the STA 102.

[0058] (Example of operation when performing data communication) FIG. 8 shows an example of a flow when the STA 102 transmits data using a connection established with the AP 101. While this example illustrates a case where the STA 102 transmits data, the AP 101 may also transmit data using a similar flow. When the STA 102 detects that data has been input to its transmission queue (S801), it initiates a channel access procedure to transmit the data. First, the STA 102 performs carrier sensing on the PCH (S802). For example, the STA 102 measures a backoff counter on the PCH and determines whether the PCH is in an idle state. If the STA 102 determines that the PCH is in an idle state (YES in S803), the STA 102 transmits a signal using a first communication method configured to enable communication by bonding the PCH and one or more NPCHs (S804). Note that after determining that the PCH is in an idle state, the STA 102 may perform carrier sensing on the NPCH for a predetermined period of time. The predetermined period may be a PIFS period immediately before the start of transmission. Furthermore, the communication device 100 may perform carrier sensing for the NPCH in parallel with carrier sensing for the PCH. The STA 102 may determine a channel to use for transmission based on the results of carrier sensing performed for each of the PCH and NPCH, and transmit a signal.

[0059] On the other hand, if the STA 102 detects a signal on the PCH during carrier sensing (NO in S803), it sets the NAV for the PCH using the duration indicated in the Duration field included in the received signal. The STA 102 determines whether the signal detected on the PCH is transmitted from a communication device connected to its own BSS. For example, the STA 102 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 STA 102 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. For example, if the signal detected on the PCH is a signal from an OBSS (YES in S805), the STA 102 performs NPCH access. On the other hand, if the signal detected in the PCH is a signal from its own BSS (NO in S807), the STA 102 determines not to perform NPCH access and waits until the PCH becomes idle (S806).

[0060] When the STA 102 performs NPCH access, it performs carrier sensing on the SPCH. At this time, the STA 102 performs carrier sensing on the SPCH identified based on information received from the AP 101. As a result, if there is a communication device attempting NPCH access in the OBSS, this communication device and the STA 102 perform carrier sensing using different SPCHs. If no signal is detected on the SPCH, the STA 102 measures the backoff counter in the same way as with carrier sensing on the PCH, and determines whether the SPCH is in an idle state. If it determines that the SPCH is in an idle state (YES in S807), the STA 102 transmits a signal using a second communication method that uses at least the SPCH (S808). Note that after determining that the SPCH is in an idle state, the STA 102 may perform carrier sensing on another NPCH for a predetermined period, similar to carrier sensing on the PCH. The STA 102 may determine a channel to use for transmission based on the results of carrier sensing performed on the SPCH and another NPCH, and transmit a signal. On the other hand, if the STA 102 detects a signal in the SPCH (NO in S808), it stops the NPCH access and postpones transmission until the NAV period set in the PCH expires (S806). If multiple SPCHs are set, the STA 102 may continue the NPCH access procedure until it confirms that all SPCHs are busy. If all SPCHs are busy, the STA 102 postpones transmission until the NAV period set in the PCH expires.

[0061] FIG. 9 shows an example of a sequence in which the STA 102 transmits data to the AP 101 using the flow of FIG. 8. In FIG. 9, the same components as those in FIG. 3 are assigned the same reference numerals, and description thereof will be omitted. That is, the STA 102 detects that communication using the PCH has been performed in the network 113 (OBSS), and the PCH has entered a busy state 301. At this time, the STA 102 attempts NPCH access using the SPCH of its own BSS identified based on information received from the AP 101. Meanwhile, in the network 122, NPCH access is attempted using the SPCH of the network 122. Then, communication using the SPCH in the second communication method is started in each SPCH. In this way, when there is only one SPCH set in the own BSS, the STA 102 is more likely to be able to communicate using NPCH access because the SPCHs in the respective networks are different. Furthermore, even when there are multiple SPCHs set in the own BSS, the STA 102 is more likely to be able to start communication using the second communication method early, thereby reducing transmission delays.

[0062] (Example of processing flow in AP) An example of a processing flow when the AP 101 determines a communication method to be used between the AP 101 and the STA 102 will be described with reference to FIG. 10. As described above, when the AP 101 is powered on and starts up, it sets a method to be used when determining an SPCH (S1001). For example, if there are multiple candidates for a pseudo-random number generation function to be used when using a random number generator or a seed to be used as an input, the AP 101 may select and set them from among them. The AP 101 determines whether to notify the STA 102 of the set pseudo-random number generation function and seed (S1002). For example, if there are multiple candidates for a pseudo-random number generation function, the AP 101 may determine to notify the STA 102 of the pseudo-random number generation function to be used in order to share it with the STA 102. Furthermore, for example, when determining an SPCH using a first determination method using a random number, the AP 101 may determine to notify the STA 102 of information identifying the seed used to obtain the random number. When the AP 101 determines to notify the STA 102 of the set pseudo-random number generation function and seed (YES in S1002), the AP 101 notifies the STA 102 of the information to be notified (S1003). The AP 101 establishes a wireless connection with the STA 102 (S1004). For example, when establishing a wireless connection with the STA 102, the AP 101 may acquire information indicating whether or not the STA 102 is capable of performing NPCH access. If the STA 102 is capable of performing NPCH access (YES in S1005), the AP 101 may cause the STA 102 to use NPCH access in communication with the STA 102 (S1006). On the other hand, if the STA 102 is not capable of performing NPCH access (NO in S1005), the AP 101 may not use NPCH access in communication with the STA 102 (S1006).

[0063] (Example of processing flow in STA) An example of a processing flow when the STA 102 determines a communication method to be used between the STA 102 and the AP 101 will be described with reference to FIG. 11. When the STA 102 is powered on and starts up, it searches for APs to which the STA 102 can connect. When the STA 102 detects the AP 101, it acquires information about functions that the AP 101 can execute and communication parameters of the BSS configured by the AP 101 (S1101). The STA 102 can acquire this information by, for example, receiving a Beacon frame or a Probe Response frame transmitted by the AP 101. In this way, the STA 102 can acquire information indicating that the AP 101 is capable of executing NPCH access. If the AP 101 is not capable of executing NPCH access (NO in S1102), the STA 102 can avoid using NPCH access in communication with the AP 101 (S1107). On the other hand, if the AP 101 has the capability to perform NPCH access (YES in S1102), the STA 102 determines whether or not it is necessary to obtain information for identifying the SPCH from the AP 101 (S1103). For example, if the Beacon frame received from the AP 101 includes information for identifying a pseudo-random number generation function or information for identifying a seed for obtaining a random number (YES in S1103), the STA 102 obtains this information (S1104). When establishing a connection with the AP 101, the STA 102 notifies the AP 101 that it has the capability to perform NPCH access (S1105). Then, the STA 102 may use NPCH access in communication with the AP 101 (S1106).

[0064] (Example of data communication processing flow) An example of a processing flow when the STA 102 performs data communication with the AP 101 will be described with reference to FIG. 12. In this example, a case where the AP 101 transmits data will be described, but a similar processing flow can also be applied when the STA 102 transmits data. When transmitting data to the STA 102, the AP 101 first performs carrier sense on the PCH. If the PCH is idle (NO in S1201), the AP 101 sets a TXOP in the PCH (S1202) and transmits the data (S1203). Note that if the NPCH is idle in addition to the PCH, the AP 101 can set a TXOP in both the PCH and the NPCH. If the set TXOP has not expired (NO in S1204), the AP 101 can continue transmitting data (S1203). When the set TXOP expires (YES in S1204), the AP 101 ends the data transmission.

[0065] When the AP 101 detects a busy state in the PCH due to the transmission of an OBS (YES in S1201), it attempts NPCH access. If the AP 101 has determined an SPCH in advance, it performs carrier sense on the SPCH (S1206). For example, when the AP 101 determines an SPCH using communication parameters that are not generally updated, such as the BSS Color of its own BSS or the MAC address of its own device, it may determine the SPCH in advance. On the other hand, when the AP 101 has not determined an SPCH in advance, it determines the SPCH before attempting NPCH access (S1205). For example, when the AP 101 determines an SPCH using updatable information such as time information or a random number, it may determine the SPCH each time it attempts NPCH access. For example, when the AP 101 determines an SPCH using the first determination method, it may determine the SPCH using a random number output by inputting a seed into a pseudo-random number generation function. If the SPCH is idle (YES in S1206), the AP 101 sets a TXOP in the SPCH (S1207) and transmits data (S1208). If the set TXOP has not expired (NO in S1209), the AP 101 can continue transmitting data (S1208). If another NPCH is idle in addition to the SPCH, the AP 101 can set a TXOP in the SPCH and that NPCH. If the set TXOP expires (YES in S1209), the AP 101 ends the data transmission.

[0066] If the SPCH is busy, the AP 101 may wait until the NAV set in the PCH expires. If multiple SPCHs are set, the AP 101 may perform carrier sensing on the SPCH with the next highest priority. If there are other SPCH candidates (YES in S1210), the AP 101 performs carrier sensing on those SPCHs. If there are multiple other SPCH candidates, the AP 101 may determine the next SPCH by further inputting a seed into a pseudo-random number generation function (S1205). If there are no other SPCH candidates, the AP 101 may wait until the NAV set in the PCH expires.

[0067] As described above, according to this embodiment, the communication device 100 performs NPCH access using an SPCH determined based on a value commonly used in its own BSS. For example, the AP 101 may determine an SPCH based on a random number acquired by the AP 101 itself. In this case, information identifying the predetermined seed used by the AP 101 to acquire the random number is notified to the BSS and may be commonly used. This allows the AP 101 and the OBSS to select different SPCHs. The AP 101 may also determine an SPCH using the BSS Color used in the AP 101 itself and the MAC address of the AP 101 itself. Because the BSS Color and MAC address are communication parameters shared with the BSS via Beacon frames, utilizing these communication parameters eliminates the need to notify the BSS of new information for determining the SPCH. The AP 101 may also determine an SPCH using time information used in the AP 101 itself. This allows the SPCH to change over time, so that even if the AP 101 uses the same SPCH as the OBSS, it will automatically use a different SPCH over time. With this configuration, when performing NPCH access, the possibility of selecting the same SPCH as the OBSS is reduced, so that it is possible to reduce the possibility of a situation in which communication in the own BSS is disabled due to the OBSS communicating on the SPCH. This makes it possible to perform NPCH access efficiently, which makes it possible to make effective use of frequency resources and improve communication performance.

[0068] 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.

[0069] (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 other communication devices using wireless frames that comply with at least one standard included in the IEEE 802.11 standard series, 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; a determination means for determining the third channel from among the second channels based on a value shared with the other communication devices in a Basic Service Set (BSS) configured by the communication device; and notifying means for notifying the other communication device of identification information used by the other communication device to identify the third channel. A communication device comprising: (Item 2) The determination means determines the third channel based on a random number obtained by inputting a value shared with the other communication device into a predetermined pseudorandom number generation function. 2. The communication device according to item 1, (Item 3) The determining means uses a value based on at least a part of a BSS Color used in a BSS formed by the communication device as the value to be shared with the other communication device. 3. The communication device according to item 1 or 2. (Item 4) The determining means uses a value based at least in part on a MAC address of the communication device providing the BSS as the value to be shared with the other communication device. 3. The communication device according to item 1 or 2. (Item 5) The determining means uses, as the value to be shared with the other communication device, a value based on at least a part of time information included in a Beacon frame transmitted by the communication device to the BSS immediately before determining the third channel. 3. The communication device according to item 1 or 2. (Item 6) The third channel determination unit determines whether or not the third channel is a channel other than the third channel. 6. The communication device according to item 5, (Item 7) The notification means notifies information indicating the third channel as the specific information. 7. The communication device according to any one of items 1 to 6, (Item 8) When a method for determining the third channel from the second channels is shared with the other communication device, the notification means notifies, as the identification information, a value shared with the other communication device and used to determine the third channel from the second channels. 7. The communication device according to any one of items 1 to 6, (Item 9) The notification means notifies the specific information using a Beacon frame or a Probe Response frame. 9. The communication device according to any one of items 1 to 8, (Item 10) A communication device that communicates with other communication devices using wireless frames that comply with at least one standard included in the IEEE 802.11 standard series, 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; and receiving means for receiving identification information that identifies the third channel determined from the second channels based on a value shared with the communication device in a Basic Service Set (BSS) configured by the other communication device. A communication device comprising: (Item 11) the identification information is information used by the communication device to determine the third channel, The communication device further includes a determining means for determining the third channel based on the identification information. 11. The communication device according to item 10. (Item 12) The third channel is determined based on a random number obtained by inputting a value shared with the communication device into a predetermined pseudorandom number generation function. 12. The communication device according to item 10 or 11. (Item 13) the receiving means receives, as the identification information, information indicating a BSS Color used in a BSS formed by the other communication device; The determining means determines the third channel using a value based at least in part on the BSS Color. Item 12. A communication device according to item 11. (Item 14) the receiving means receives, as the identification information, information indicating a MAC address of the other communication device that provides the BSS; The determining means determines the third channel using a value based on at least a part of a MAC address of the other communication device. Item 12. A communication device according to item 11. (Item 15) the receiving means receives, as the identification information, time information included in a Beacon frame transmitted by the other communication device to the BSS; The determination means determines the third channel using a value based on at least a part of time information included in a Beacon frame received immediately before the communication device determines the third channel. Item 12. A communication device according to item 11. (Item 16) The third channel determination unit determines whether or not the third channel is a channel other than the third channel. Item 16. The communication device according to item 15. (Item 17) The receiving means receives the specific information using a Beacon frame or a Probe Response frame. 17. A communication device according to any one of items 10 to 16. (Item 18) 1. A control method executed by a communication device that communicates with another communication device 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; a determining step of determining the third channel from among the second channels based on a value shared with the other communication devices in a Basic Service Set (BSS) configured by the communication device; a notification step of notifying the other communication device of identification information used by the other communication device to identify the third channel. A control method comprising: (Item 19) 1. A control method executed by a communication device that communicates with another communication device 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; and receiving identification information that identifies the third channel determined from the second channels based on a value shared with the communication device in a Basic Service Set (BSS) configured by the other communication device. A control method comprising: (Item 20) 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 17.

[0070] 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]

[0071] 101: AP, 102: STA, 103: Network, 111: AP, 112: STA, 113: Network, 121: AP, 122: STA, 123: Network

Claims

1. A communication device that communicates with other communication devices using wireless frames that comply with at least one standard included in the IEEE 802.11 standard series, 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; a determination means for determining the third channel from among the second channels based on a value shared with the other communication devices in a Basic Service Set (BSS) configured by the communication device; and notifying means for notifying the other communication device of identification information used by the other communication device to identify the third channel. A communication device comprising:

2. The determination means determines the third channel based on a random number obtained by inputting a value shared with the other communication device into a predetermined pseudorandom number generation function.

2. The communication device according to claim 1.

3. The determining means uses a value based on at least a part of a BSS Color used in a BSS formed by the communication device as the value to be shared with the other communication device.

2. The communication device according to claim 1.

4. The determining means uses a value based at least in part on a MAC address of the communication device providing the BSS as the value to be shared with the other communication device.

2. The communication device according to claim 1.

5. The determining means uses, as the value to be shared with the other communication device, a value based on at least a part of time information included in a Beacon frame transmitted by the communication device to the BSS immediately before determining the third channel.

2. The communication device according to claim 1.

6. The third channel determination unit determines whether or not the third channel is a channel other than the third channel.

6. The communication device according to claim 5.

7. The notification means notifies information indicating the third channel as the specific information.

2. The communication device according to claim 1.

8. When a method for determining the third channel from the second channels is shared with the other communication device, the notification means notifies, as the identification information, a value shared with the other communication device and used to determine the third channel from the second channels.

2. The communication device according to claim 1.

9. The notification means notifies the specific information using a beacon frame or a probe response frame.

2. The communication device according to claim 1.

10. A communication device that communicates with other communication devices using wireless frames that comply with at least one standard included in the IEEE 802.11 standard series, 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; and receiving means for receiving identification information that identifies the third channel determined from the second channels based on a value shared with the communication device in a Basic Service Set (BSS) configured by the other communication device. A communication device comprising:

11. the identification information is information used by the communication device to determine the third channel, The communication device further includes a determining means for determining the third channel based on the specific information.

11. The communication device according to claim 10.

12. The third channel is determined based on a random number obtained by inputting a value shared with the communication device into a predetermined pseudorandom number generation function.

11. The communication device according to claim 10.

13. the receiving means receives, as the identification information, information indicating a BSS Color used in a BSS formed by the other communication device; The determining means determines the third channel using a value based at least in part on the BSS Color.

12. The communication device according to claim 11.

14. the receiving means receives, as the identification information, information indicating a MAC address of the other communication device that provides the BSS; The determining means determines the third channel using a value based on at least a part of a MAC address of the other communication device.

12. The communication device according to claim 11.

15. the receiving means receives, as the identification information, time information included in a Beacon frame transmitted by the other communication device to the BSS; The determination means determines the third channel using a value based on at least a part of time information included in a Beacon frame received by the communication device immediately before determining the third channel.

12. The communication device according to claim 11.

16. The third channel determination unit determines whether or not the third channel is a channel other than the third channel.

16. The communication device according to claim 15.

17. The receiving means receives the specific information using a Beacon frame or a Probe Response frame.

11. The communication device according to claim 10.

18. 1. A control method executed by a communication device that communicates with another communication device using a wireless frame that complies with at least one standard included in the IEEE 802.11 standard series, 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; a determining step of determining the third channel from the second channels based on a value shared with the other communication devices in a Basic Service Set (BSS) configured by the communication device; a notification step of notifying the other communication device of identification information used by the other communication device to identify the third channel. A control method comprising:

19. 1. A control method executed by a communication device that communicates with another communication device using a wireless frame that complies with at least one standard included in the IEEE 802.11 standard series, 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; and receiving identification information that identifies the third channel determined from the second channels based on a value shared with the communication device in a Basic Service Set (BSS) configured by the other communication device. A control method comprising:

20. 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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