Communication device, communication method, and program

Abstract

To improve channel utilization efficiency in a communication system using a communication link constituted by a plurality of channels.SOLUTION: A communication device has communication means that, in one communication link consisting of a first channel used to acquire a transmission right and one or more second channels, can communicate with a first communication device using a first communication method using one or more channels including the first channel, and a second communication method using the one or more second channels when the first channel is unavailable, detection means that detects whether the first channel has become available in a period in which the communication device is communicating with the first communication device using the second communication method, and control means that performs control for communication using the first channel when the first channel becomes available in the period in which communication is being performed using the second communication method.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] In recent years, with the increase in the amount of data being communicated, the development of communication technologies such as wireless LAN (Local Area Network) is progressing. The IEEE (Institute of Electrical and Electronic Engineers) 802.11 standard series is known as a major communication standard for wireless LAN. The IEEE 802.11 standard series includes IEEE 802.11a / b / g / n / ac / ax / be standards. In order to further improve the reliability of communication, the IEEE 802.11bn standard is being developed as a successor to the IEEE 802.11be standard. In the IEEE 802.11 Working Group (WG) that formulates the IEEE 802.11bn standard, the UHR SG defines the goals and scope of the standard, and the TGbn defines the detailed technical content to be included in the standard. UHR SG is an abbreviation 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 using 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. Pat. No. 1,169,6353 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 using a communication link consisting of multiple channels. [Means for solving the problem]

[0006] A communication device according to one embodiment of the present invention is a communication device that communicates in accordance with the IEEE 802.11 series standard, and has a communication means that can communicate with a first communication device using a first communication method that uses one or more channels including the first channel in a single communication link consisting of a first channel used to acquire a transmission right and one or more second channels different from the first channel, and a second communication method that uses one or more of the second channels when the first channel is unavailable, a detection means that detects whether the first channel has become available during a period when the communication device is communicating with the first communication device using the second communication method, and a control means that performs control for communication using the first channel when the first channel becomes available during a period when communication is being performed using the second communication method. Effect of the Invention

[0007] According to the present invention, frequency resources can be utilized more efficiently in a communication system using a communication link consisting of multiple channels. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. [Diagram 2] 1 is a schematic diagram illustrating an example of a time chart when a communication device transmits data. [Diagram 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. [Diagram 5] FIG. 13 is a diagram showing an example of a time chart when signals are exchanged between a PCH and an NPCH. [Figure 6] FIG. 11 is a diagram illustrating an example of a flow showing an operation of a communication device during reception. [Figure 7] FIG. 13 is a diagram showing an example of a time chart when signals are exchanged between a PCH and an NPCH. [Figure 8] FIG. 11 is a diagram illustrating an example of a flow showing an operation of a communication device during reception. [Figure 9] FIG. 13 is a diagram showing an example of a time chart for exchanging signals in a PCH, NPCH and other links. [Figure 10] FIG. 11 is a diagram illustrating an example of a flow showing an operation of a communication device during reception. [Figure 11] 13 is a diagram showing an example of a notification signal notifying that a PCH has become available; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are 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 and 103. The AP 101, STA 102, and STA 103 are communication devices capable of performing wireless communication conforming to the IEEE 802.11 series standard. IEEE is an abbreviation for Institute of Electrical and Electronics Engineers. FIG. 1 shows a configuration in which the STA 102 and STA 103 participate in a network 10 constructed by the AP 101. The network 10 may also be called a Basic Service Set (BSS). In FIG. 1, a configuration in which one AP 101 and two STAs 102 and 103 exist is shown, but there may be one or more APs and STAs. In addition, at that time, multiple STAs may be connected to one AP, and one STA may be connected to multiple APs. In FIG. 1, a network 11 consisting of AP111 and STA112 exists in the vicinity of a network 10 consisting of AP101, STA102, and STA103. AP111 and STA112 are communication devices capable of performing wireless communication conforming to the IEEE802.11 series standard, similar to AP101, STA102, and STA103. For AP101, STA102, and STA103, the network 10 is a BSS to which the device itself connects, and may be called its own BSS. On the other hand, for AP101, STA102, and STA103, the network 11 is a network that may cause interference to the device itself, and may be called an overlapping BSS (OBSS). In this embodiment, AP101, AP111, STA102, STA103, and STA112 may be collectively called a communication device 100. Also, AP101 and AP111 may be simply called an AP, and STA101, STA102, and STA103 may be simply called an STA.

[0011] In this embodiment, the communication device 100 is configured to be able to execute a communication method conforming to the IEEE802.11bn standard. The IEEE802.11bn standard is a successor standard to the IEEE802.11be standard that targets a maximum transmission speed of 46.08 Gbps (Giga bit per second). The main feature of the IEEE802.11bn standard is that it has a function of realizing 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 an 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 the names UHR, IEEE802.11bn, etc. may be changed to other names when the formulation of the standard is completed. It should be noted that this specification and the claims attached hereto are applicable to communication devices using all successor standards to the IEEE802.11be. The communication device 100 may be compatible with at least one of legacy standards that are standards prior to the IEEE802.11bn standard. The legacy standards are, for example, the IEEE802.11a / b / g / n / ac / ax / be standards. The communication device 100 may also be compatible with other communication standards such as Bluetooth (registered trademark), NFC, UWB, ZigBee, MBOA, etc. 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, etc. The communication device 100 may also be compatible with communication standards such as wired LAN. The AP is, for example, a wireless LAN router or a personal computer (PC), but is not limited to these. The AP may be an information processing device such as a wireless chip capable of performing wireless communication conforming to the IEEE802.11bn standard or the like.The STA 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 may be an information processing device such as a wireless chip capable of performing wireless communication compatible with the IEEE802.11bn standard or the like.

[0012] The communication device 100 may communicate using radio signals in frequency bands such as 2.4 GHz, 3.6 GHz, 5 GHz, and 6 GHz, as well as 45 GHz and 60 GHz bands known as millimeter waves. The frequency bands used by the communication device 100 are not limited to these, and may be, for example, the Sub1 GHz band. The communication device 100 may communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by the communication device 100 are not limited to these, and may be, for example, 240 MHz, 4 MHz, and the like. The IEEE802.11 series standard specifies a frequency channel using a bandwidth of 20 MHz as a basic channel in frequency bands such as 2.4 GHz, 5 GHz, and 6 GHz. This standard also defines a number of available channels in each of the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. In this standard, the communication device 100 can use a certain channel in combination with another adjacent channel. Such use of a certain channel in combination with another adjacent channel can be called channel bonding. A bundle of channels formed by one or two or more adjacent channels can be called a communication link. That is, one link formed by two channels with a bandwidth of 20 MHz can use a bandwidth of 40 MHz. In the IEEE802.11be standard, 320 MHz is scheduled to be specified as the maximum bandwidth available for one link. Furthermore, signals transmitted in this bandwidth may be continuous or discontinuous on the frequency axis. The AP and STA may be AP MLD (Multi-Link Device) and STA MLD, respectively, corresponding to Multi-Link, which establishes multiple links simultaneously and communicates. Communication between communication devices by establishing multiple links simultaneously can be called multi-link 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 the presence or absence of a signal 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 exists when the received signal strength exceeds a predetermined threshold (physical carrier sense). The received signal strength may also be called 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 a signal received on a channel (virtual carrier sense). For example, the communication device 100 stores a period indicated by a Duration field included in a received signal as a Network Allocation Vector (NAV) in the communication device 100. The communication device 100 may handle the stored NAV as a period during which the communication device 100 does not transmit a signal. In this embodiment, the operation of the communication device 100 to set a period during which the device itself does not transmit based on information such as the Duration field of a received signal is called setting a NAV. That is, until the NAV set for the channel expires, the communication device 100 determines that a signal exists on the channel. In this way, the communication device 100 determines whether or not a signal exists on the channel based on the results of performing physical carrier sense and virtual carrier sense. When the communication device 100 determines that a signal exists on the channel, it may determine that transmission is not possible. In this case, the state of the channel may be called a busy state. On the other hand, a state in which no signal is detected on the channel in the carrier sense and the NAV is not set may be called an idle state. When the channel is in an idle state, the communication device 100 may determine that transmission is possible.

[0014] For example, when the communication device 100 communicates using a link with a bandwidth of 160 MHz, the communication device 100 can determine whether or not transmission is possible using only a Primary Channel (PCH) with a bandwidth of 20 MHz included in the link. For example, the IEEE 802.11 series standard describes that the communication device 100 can start transmission when it determines that transmission is possible as a result of performing carrier sense on the PCH for a predetermined period. The predetermined period is determined by an Interframe Space (IFS) determined for each access category that classifies the type of communication traffic, and a random number (backoff counter) that is randomly determined from a predetermined range. That is, when the communication device 100 determines that the PCH is in an idle state for this predetermined period, it acquires a transmission right for transmission using the link. At this time, when a channel other than the PCH is in an idle state during a PIFS period immediately before the start of transmission, the communication device 100 can perform transmission by channel bonding using the idle channel and the PCH. PIFS is an abbreviation for Priority Interframe Space. Furthermore, when the communication device 100 determines that transmission is not possible as a result of performing carrier sensing on the PCH, the communication device 100 may postpone transmission even if other channels included in the same link are in an idle state. Each channel other than the PCH that constitutes one link may be called a secondary channel (SCH). The secondary channel may also be called a non-primary channel (NPCH).

[0015] In the communication device 100, when a signal is received on a certain channel, if a signal is transmitted on another channel (for example, an adjacent channel) arranged at a frequency close to the channel, the received signal may not be properly received. For example, assume that the communication device 100 can simultaneously perform transmission processing and reception processing using different channels. When the communication device 100 receives using a certain channel, if it transmits on an adjacent channel, the power of the transmission signal leaks into the channel of the received signal, causing interference with the received signal. Generally, the power due to such leakage of the transmission signal is much greater than the received power of the received signal, so that the received signal is not properly received. In order to avoid such a situation, the IEEE802.11 series standard provides a mechanism for preventing another communication device from transmitting a signal to the 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 transmission is possible, and it is stipulated that while one communication device is transmitting using the PCH, the other communication device does not transmit even if the other channel is in an idle state. As a result, while a communication device is transmitting a signal and the PCH is in use, other communication devices do not transmit signals using channels adjacent to the PCH, so that the communication device does not receive a signal on the adjacent channel. Therefore, the above-mentioned problem of interference caused by power leakage between channels can be solved.

[0016] However, not using other channels (NPCH) that are in an idle state based on the PCH being busy may hinder efficient use of frequency resources of the entire link. FIG. 2(A) shows an example of a time chart when STA102 transmits data to AP101. In FIG. 2(A), STA102 performs carrier sense on PCH, confirms that it is in an idle state, and then transmits data using PCH with a bandwidth of 20 MHz. In this case, for example, even if seven NPCHs other than PCH are in an idle state, other communication devices are not allowed to communicate using NPCH. Also, FIG. 2(B) shows another example of a time chart when STA102 transmits data to AP101. In FIG. 2(B), while STA102 is performing carrier sense on PCH, PCH is used by another network (for example, network 11 in FIG. 1) that exists in the geographical vicinity of STA102. In this case, since the PCH is determined to be busy in the carrier sense by the STA 102, even if the seven NPCHs other than the PCH are idle, the STA 102 is not permitted to communicate with the AP 101 using the NPCH. However, since the AP 101 is not transmitting at this time, even if the STA 102 transmits to the AP 101 using the NPCH, the AP 101 can properly receive the signal transmitted by the STA 102. In this way, if the PCH with a bandwidth of, for example, 20 MHz is used by another network, and the remaining NPCH with an idle bandwidth of 140 MHz is not used, the frequency resources cannot be used efficiently.

[0017] In consideration of such circumstances, in this embodiment, when a PCH is being used by another communication device, a function is provided for communication between communication devices using an NPCH included in the same link as the PCH without using the PCH. As an example, when the PCH is busy, the communication device 100 sets a Secondary Primary Channel (SPCH) used to acquire a transmission right for transmission using the NPCH. The SPCH is one or more channels among the NPCH included in the same link as the PCH. When the communication device 100 determines that the PCH is being used by another communication device, it then determines whether transmission is possible in the SPCH. 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 for performing transmission using one or more channels including the SPCH without using a PCH is called NPCH access (Non-Primary Channel Access). Note that this communication method may be called by other names. For example, this communication method may be called SCA (Secondary Channel Access).

[0018] In this embodiment, the communication device 100 communicates using a first communication method using one or more channels including a PCH and a second communication method (NPCH access) using one or more NPCHs not including a PCH. For example, the communication device 100 has a function of executing both the first communication method and the second communication method, and may communicate using the first communication method when the PCH can be used, and may communicate using the second communication method when the PCH cannot be used. A case where the PCH cannot be used is, for example, a case where a NAV is set in the communication device 100 because another communication device has started communication in the PCH. Here, the NPCH access may be set to end within the period of the NAV set in the PCH. Alternatively, the NPCH access may be permitted only when it ends within the period of the NAV set in the PCH. If the NPCH is busy when the PCH goes from a busy state to an idle state, the next communication may be performed only by the PCH without using the NPCH. And, when the NPCH goes from a busy state to an idle state, the PCH may be busy. In this way, when the PCH and the NPCH are used independently, the frequency resources may not be used efficiently. To avoid such a situation, the communication device 100 may control the NPCH access so that the NPCH access is completed within the period of the NAV set in the PCH. On the other hand, even if the NPCH access is controlled so that the NPCH access is completed within the period of the NAV set in the PCH, the NAV set in the PCH may end before the completion of the NPCH access. For example, the NAV set in the communication device 100 may be terminated (cancelled) by a CF (Contention Free)-END frame or the like. By canceling the NAV set in the PCH, the communication device 100 becomes able to use the PCH. As a result, for example, when the AP 101 and the STA 102 are communicating by the NPCH access, the STA 103 may transmit to the AP 101 using the PCH. On the other hand, if the AP 101 is not performing a receiving operation in the PCH while the NPCH access is being performed, the AP 101 may not receive a signal transmitted by the STA 103.In addition, as described above, when the PCH and the NPCH are used independently, there is a possibility that frequency resources are not used efficiently. In this embodiment, in a situation where the NPCH access is being performed between the AP and the STA, when the NAV set in the PCH ends earlier than the initial setting, the communication device 100 provides a technique for controlling communication using the PCH.

[0019] (Device configuration) 3 shows an example of a hardware configuration of the communication device 100 (AP and STA) according to the present 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.

[0020] 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 are abbreviations for Read Only Memory and Random Access Memory, respectively. The storage unit 301 may be configured to include storage media such as a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, and a DVD, in addition to memories such as ROM and RAM.

[0021] 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 by a multi-core or the like, the entire communication device 100 may be configured to be controlled by the multiple processors.

[0022] 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 above-mentioned predetermined processes. For example, if the device is a camera, the functional unit 303 is an image capture unit that performs image capture processing. Also, for example, if the device is a printer, the functional unit 303 is a print unit that performs print processing. Also, for example, if the device is a projector, the functional unit 303 is a projection unit that performs projection processing.

[0023] 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, a voice 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 devices integrated with the communication device 100, or may be separate devices.

[0024] The communication unit 306 controls wireless communication conforming to the IEEE802.11bn standard. The communication unit 306 may control wireless communication conforming to other IEEE802.11 series standards such as legacy standards in addition to the IEEE802.11bn 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 and the Bluetooth standard and wired communication such as wired LAN in addition to the IEEE802.11bn standard, the communication unit 306 may control communication conforming to these communication standards. If the communication device 100 can perform wireless communication conforming to multiple communication standards, the communication device 100 may have a configuration having a communication unit and an antenna corresponding to each communication standard separately. The communication device 100 communicates data with the other communication device via the communication unit 306. The antenna 307 may be configured separately from the communication unit 306, or may be configured together with the communication unit 306 as one module. The communication device 100 may include a communication unit 306 for communication using the PCH and a communication unit 306 for NPCH access. The communication unit 100 may include a main communication unit 306 used for communication with other communication devices, and a secondary communication unit 306 used to determine whether the PCH has become available while the NPCH access is being performed. For example, the secondary communication unit 306 may be a simple circuit having only a function required to determine whether the PCH has become available. When the communication device 100 has a plurality of communication units 306, some of the communication units 306 may be used for NPCH access, and the other communication units 306 may be configured to perform communication using the PCH. In this case, all communication units 306 may be used for communication using the PCH while the NPCH access is not being performed. The communication unit 100 may use the multiple communication units 306 while switching between roles or uses. For example, the communication unit 306 used for communication using the PCH in a first period may be used for communication using the NPCH access in a second period.The AP 101 may have a circuit that performs reception processing on signals received on the PCH and NPCH channels in parallel.

[0025] Antenna 307 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. In Fig. 3, communication device 100 is shown having two antennas 307, but communication device 100 may have one or three or more antennas, and may have one or more antennas for each frequency band that the device can use. In addition, when communication device 100 has multiple antennas, communication device 100 may have a communication unit 306 for each antenna.

[0026] (Functional configuration) FIG. 4 shows an example of a 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 a program stored in one or more memories. The communication device 100 includes a frame analysis unit 401, a NAV detection unit 402, a wireless communication control unit 403, an NPCH access control unit 404, a PCH communication control unit 405, and a frame generation unit 406. However, this is an example, and dedicated hardware for implementing each function may be prepared. Note that the configuration shown in FIG. 4 is an example, and the AP may include configurations other than these configurations. In addition, two or more functional blocks in FIG. 4 may be implemented as one functional block, or one functional block may be divided into two or more functional blocks.

[0027] The frame analysis unit 401 analyzes a signal (frame) received by the communication unit 306 via the antenna 307. For example, when the frame analysis unit 401 receives a frame on a channel, it extracts a Duration field included in the frame and notifies the NAV detection unit 402 of the extracted Duration field. When the frame analysis unit 401 receives a frame addressed to the device itself, it extracts data included in the frame and passes the extracted data to a higher layer. When the frame analysis unit 401 receives a frame for canceling the NAV set in the PCH, it notifies the NAV detection unit 402 of the frame. In this embodiment, a signal for canceling the NAV set in the channel is also called a completion signal. When the frame analysis unit 401 receives a frame for notifying that the PCH has become available while the communication device 100 is performing NPCH access, it notifies the NPCH access control unit 404 of the frame. When the communication device 100 is executing NPCH access and receives a frame instructing the end of NPCH access, the frame analysis unit 401 notifies the NPCH access control unit 404 of the frame. The frame informing that the PCH has become available and the frame instructing the end of NPCH access may be received on a link other than the link executing NPCH access. In addition, the notification that the PCH has become available and the instruction to end NPCH access may be included in a response to the frame transmitted in NPCH access.

[0028] The NAV detection unit 402 sets or updates the NAV for the PCH or SPCH based on the Duration notified by the frame analysis unit 401 or the notification of the cancellation of the set NAV. For example, when the NAV detection unit 402 acquires information on the Duration from the frame analysis unit 401, it sets the NAV for the target channel. On the other hand, when the NAV detection unit 402 receives a notification of the cancellation of the NAV from the frame analysis unit 401, it resets (sets to zero) the NAV set for the target channel. Furthermore, when the NAV is set for the PCH, the NAV detection unit 402 determines whether the PCH is available. When the PCH is available, the NAV detection unit 402 notifies the PCH communication control unit 405. The NAV detection unit 402 can determine that the PCH is available based on receiving a completion signal in the PCH from the frame analysis unit 401.

[0029] The wireless communication control unit 403 performs a transmission process for each frame generated by the frame control unit 406. The wireless communication control unit 403 also notifies the frame analysis unit 401 of the frame received via the antenna 307. For example, the wireless communication control unit 403 may execute transmission or reception of a data frame using either the first communication method or the second communication method. As an example, the wireless communication control unit 403 executes carrier sense of the PCH when transmitting a data frame. When a signal is detected in the PCH or the NAV is set in the NAV detection unit 402, the wireless communication control unit 403 may execute carrier sense of the SPCH. For example, when the wireless communication control unit 403 does not detect a signal in the SPCH and the NAV detection unit 402 does not set the NAV in the SPCH, the wireless communication control unit 403 transmits a data frame using one or more NPCHs including the SPCH. When the communication device 100 includes a plurality of communication units 306, the wireless communication control unit 403 executes communication using each of the communication units 306. Furthermore, when the communication device 100 has established multiple links with other communication devices, the wireless communication control unit 403 executes communication using each link.

[0030] The NPCH access control unit 404 executes settings and control for performing NPCH access. For example, when the communication device 100 is performing NPCH access and is notified by the frame analysis unit 401 that the PCH has become available, the NPCH access control unit 404 determines whether or not to end the NPCH access. When it is determined that the NPCH access is to be ended, the NPCH access control unit 404 instructs the frame generation unit 406 to generate a signal for canceling the NAV set in the NPCH. Furthermore, when the NPCH access control unit 404 receives an instruction to end the NPCH access from the frame analysis unit 401, it instructs the frame generation unit 406 to generate a completion signal for canceling the NAV set in the NPCH according to this instruction.

[0031] When the PCH communication control unit 405 is notified by the NAV detection unit 402 that the PCH has become available, the PCH communication control unit 405 performs control for communication using the PCH. The control for communication using the PCH performed by the PCH communication control unit 405 will be described in detail below. The PCH communication control unit 405 can control each functional unit including the wireless communication control unit 403 for communication using the PCH. The frame generation unit 406 generates a frame when the communication device 100 communicates with the other communication device. The frame generation unit 406 generates frames including, for example, a reservation signal for reserving a channel, a notification that the PCH has become available, a completion signal for canceling the NAV set in the channel, and the like, and notifies the wireless communication control unit 403.

[0032] (Example of processing executed in a communication device) Hereinafter, in this embodiment, several examples of the flow of the process executed by the communication device 100 will be described. In this process example, an example will be described in which the AP 101 receives a signal transmitted by NPCH access from the STA 102 when NAV is set in the PCH. Note that the following process example will be described as the operation of the AP 101, but it can also be applied to the operation of the STA 102.

[0033] [Processing example 1] FIG. 5 shows an example of a time chart regarding signals exchanged in each of the PCH and NPCH in this processing example. First, at time t1, it is assumed that AP111 belonging to the OBSS transmits a data frame 501 addressed to STA112 on the PCH. AP101 and STA102 set NAV503 in the PCH based on the value of the Duration field included in the received data frame 501. When STA112 receives the data frame 501 normally, it transmits ACK502. On the other hand, when data addressed to AP101 is accumulated in the transmission buffer in STA102, STA102 starts a channel access procedure for transmitting this data. That is, STA102 performs carrier sense in the PCH, and when it is confirmed that the PCH is in an idle state, it starts transmitting this data. Here, since NAV503 is set in the PCH, STA102 performs carrier sense of the SPCH according to the NPCH access procedure. Based on the fact that the SPCH has been idle for a certain period including the back-off counter, the STA 102 starts transmitting a data frame 504 addressed to the AP 101 at time t2. At this time, the STA 102 may perform transmission using one or more NPCHs including the idle SPCH. In addition, when transmitting the data frame 504, the STA 102 may acquire a Transmission Opportunity (TXOP) in a channel used for transmission. The TXOP is a period during which a communication device that has acquired a transmission right to a channel occupies the channel based on the transmission right. For example, the STA 102 may acquire, as a TXOP, a period including a required time for transmitting two pieces of data 504 and 506 to the AP 101 and a required time for receiving ACKs 505 and 507, which are acknowledgements to each piece of data, from the AP 101. The TXOP may be indicated by a Duration field included in the header of the data frame 504, or may be indicated through exchange of an RTS frame and a CTS frame (RTS / CTS exchange) not shown.In this case, information indicating TXOP may be stored in the Duration field of each of the RTS frame and the CTS frame transmitted prior to the data frame 504. Note that RTS and CTS are abbreviations for Request To Send and Clear To Send, respectively. The communication device 100 that receives the data frame 504 or the like sets the NAV 508 for a period corresponding to the TXOP. As a result, the communication device that acquires the transmission right of the channel may occupy the channel during the TXOP period. Note that the STA 102 may set a period shorter than the period until the expiration of the NAV 503 set in the PCH as the TXOP period. As a result, if the NPCH is available when the NAV 503 in the PCH expires, it becomes possible to perform channel bonding using the PCH and the NPCH at the next transmission opportunity. Note that, although this example illustrates a case where the STA 102 acquires a TXOP in the NPCH, the present invention is not limited to this. If the AP 101 has data to transmit, the AP 101 may also attempt to acquire a TXOP in the NPCH. When the AP 101 wins channel access in the NPCH, the AP 101 may transmit data addressed to the STA in the NPCH. Returning to the description of FIG. 5, at time t3, a CF-END frame 509 is transmitted in the PCH as a completion signal for canceling the NAV 503 set in the PCH. The CF-END frame 509 may be transmitted by the AP 111. As a result, a new signal may be transmitted in the PCH based on the fact that the PCH has become available. In the example of FIG. 5, at time t4, the STA 103 starts transmitting a data frame 510 addressed to the AP 101 using the PCH. For example, if the STA 103 is a communication device that communicates using only the PCH, the STA 103 may transmit a data frame 510 to the AP 102 using an idle PCH, regardless of whether the AP 102 is communicating by NPCH access.

[0034] In this processing example, when the PCH becomes available while the AP101 is receiving the data frame 504 in the NPCH, the AP101 performs an operation for receiving a signal transmitted in the PCH. For example, the AP101 first performs monitoring to determine whether the PCH becomes available or not in parallel with communication by the NPCH access. As an example, the AP101 may determine that the PCH has become available by detecting a completion signal in the PCH. When the AP101 determines that the PCH has become available, it starts a receiving operation in the PCH in preparation for receiving a signal that may be transmitted to the PCH. Then, when the AP101 detects a new signal in the PCH, it starts a receiving process of this signal. When the signal received in the PCH is a signal addressed to the AP101's own device (for example, the data frame 510), the AP101 may perform a receiving process of this signal and transfer the acquired data to a higher layer. Furthermore, when the signal received in the PCH is not a signal addressed to the AP101's own device, the AP101 may stop the receiving process or discard the received signal. In this way, by performing a receiving operation on the PCH based on detection that the PCH has become available while performing communication via NPCH access, the AP 101 can normally receive signals transmitted on the PCH.

[0035] FIG. 6 shows an example of a flow of the reception operation executed by the AP 101 in the time chart of FIG. 5. This reception operation is applicable not only to the AP 101 but also to the communication device 100 including the STA 102, so the operation of the communication device 100 will be described below. First, the communication device 100 detects a signal in the PCH. When a signal is received in the PCH (YES in S601), the communication device 100 judges whether the signal is a signal of the own BSS or a signal of the OBSS based on whether the BSS Color field included in the received signal matches the BSS Color of the own BSS. In addition, the communication device 100 can judge whether the signal is a signal of the own BSS or a signal of the OBSS based on whether the values ​​stored in the destination field, the source field, etc. included in the received signal match the parameters of the own BSS. If the received signal is a signal of the own BSS, the communication device 100 executes normal reception processing (S603). In normal reception processing, for example, if the signal is addressed to the device itself based on the destination field of the received signal, data, etc. are extracted from the signal and transferred to a higher layer, etc. Also, if the signal is not addressed to the device itself, the signal is discarded. On the other hand, if the received signal is not a signal of the device itself (NO in S602), the communication device 100 sets a NAV in the PCH based on the value of the Duration field included in the received signal (S604). Then, the communication device 100 executes detection of a signal in the SPCH. If the NAV set in the PCH expires before detecting a signal in the SPCH (YES in S605 and YES in S606), the communication device 100 returns to S601 and continues processing.

[0036] On the other hand, when a signal transmitted using one or more NPCHs including this SPCH is detected in the SPCH (YES in S605), the communication device 100 executes a reception process for this signal. Also, while executing this reception process, the communication device 100 executes monitoring of the PCH in parallel. Here, if the PCH becomes available before the reception process is completed (YES in S608), the communication device 100 performs control for communication using the PCH (S609). The control for communication using the PCH may be, for example, a reception operation of a new signal in the PCH or detection of a signal for receiving a new signal. When the communication device 100 receives a new signal in the PCH, it may perform reception processing of the received signal similarly to the processes in S601 to S604. Note that, during the period when the communication device 100 sets the NAV in the PCH, it may operate only the minimum functions necessary for monitoring the PCH with respect to the functions provided for communication in the PCH, and may operate the other functions in a power-saving manner. Also, when the communication device 100 detects that the PCH has become available, it may shift these functions from power saving operation to normal reception operation. By performing power saving operation during the NAV period, it is possible to reduce power consumption. If the signal received in S605 is not an OBSS signal or is not addressed to the communication device 100, the communication device 100 may set a NAV based on the value of the Duration field included in this signal to the SPCH and wait for the reception process until this NAV expires. When the communication device 100 completes the reception process of the signal by the NPCH access (NO in S608 and YES in S607), it continues carrier sense of the SPCH until the NAV set in the PCH expires (S606). When the NAV of the PCH expires, the communication device 100 returns to S601 and continues the process. Although not shown in FIG. 6, as described above, the communication device 100 can also attempt to acquire a TXOP in the NPCH at the timing after the NAV is set in the PCH. When the communication device 100 wins the TXOP of the NPCH, it may execute a data transmission process using the NPCH instead of the process of S605-S606. In this case, the communication device 100 performs the data transmission process while monitoring the PCH in parallel.

[0037] In the above, an example of executing reception processing in the PCH as control performed by the communication device 100 for communication using the PCH when the PCH becomes available has been described, but the control performed by the communication device 100 for communication using the PCH is not limited to this. For example, the communication device 100 may execute transmission processing in the PCH. For example, at time t4 in FIG. 5, the AP 101 may transmit a signal addressed to the STA 103 in the PCH. At this time, the transmission power in the PCH may cause interference with the NPCH. On the other hand, when there are multiple NPCHs, the NPCH in which the AP 101 receives a data frame from the STA 102 and the PCH may be separated on the frequency axis. For example, when the NPCH in which the AP 101 receives a signal from the STA 102 and the PCH are separated on the frequency axis, the AP 101 may determine to execute transmission in the PCH when the NPCH in which the AP 101 receives a signal from the STA 102 and the PCH are separated on the frequency axis and the interference power caused in the NPCH by the transmission in the PCH is smaller than a threshold value.

[0038] 5 shows an example in which AP101 receives signals on PCH and NPCH, but when AP101 transmits a signal addressed to STA102 by NPCH access, AP101 may transmit a signal addressed to STA103 at time t4. At this time, AP101 may adjust the length of the data frame and the transmission period so that the downlink signal addressed to STA102 or STA103 and the uplink signal received from STA102 or STA103 do not overlap on the time axis. For example, AP101 may insert padding or the like into the signal transmitted to STA103 so that the signal transmitted to STA102 and the ACK received from STA103 do not overlap on the time axis, and adjust the signals transmitted to each STA to complete transmission at the same time. By aligning the end times of communications using the PCH and NPCH access, AP 101 can avoid mutual interference between these communications and enable channel bonding using the PCH and NPCH at the next transmission opportunity.

[0039] As described above, in this processing example, the communication device 100 performing communication by NPCH access determines whether or not the PCH becomes available in parallel, and when the PCH becomes available during communication by NPCH access, performs control for communication using the PCH. For example, as control for communication using the PCH, by starting a receiving operation in the PCH, it becomes possible to receive a new signal addressed to the device in the PCH. Also, when the communication device 100 is performing transmission by NPCH access, as control for communication using the PCH, it is possible to avoid transmitting a signal addressed to the device using the PCH. Also, by the communication device 100 adjusting the end time of communication using the PCH and communication using the NPCH access, it becomes possible to perform channel bonding using both the PCH and the NPCH at the next transmission opportunity.

[0040] [Processing example 2] In the processing example 1, the operation of the AP 101 is described using an example in which the AP 101 performing communication by NPCH access receives or transmits data in the PCH when it determines that the PCH is available. In this processing example, the operation of the AP 101 is described using an example in which the AP 101 performing communication by NPCH access transmits a signal that inhibits other communication devices from transmitting in the PCH when it determines that the PCH is available. FIG. 7 shows an example of a time chart related to signals exchanged in the PCH and NPCH in this processing example. The same reference numbers are given to operations similar to those in FIG. 5, and the description is omitted. First, at time t1, the AP 111 transmits a data frame 501 addressed to the STA 112 in the PCH, and the AP 101 and the STA 102 that receive the data frame set the NAV 503 in the PCH. At time t2, the STA 102 starts transmitting a data frame 504 addressed to the AP 101 using the NPCH access. At time t3, a CF-END frame 509 that cancels the NAV 503 set in the PCH is transmitted. As a result, a new signal addressed to the AP 101 may be transmitted on the PCH based on the fact that the PCH is available. When the AP 101 determines that the PCH is available, the AP 101 transmits a signal that suppresses transmission on the PCH at time t4. As a result, the AP 101 may avoid a signal addressed to the AP 101 being transmitted using the PCH. For example, the AP 101 transmits a reservation signal 701 that reserves a channel on the PCH in order to suppress transmission on the PCH. As an example, the signal that reserves the channel may be a CTS-to-Self frame. The CTS-to-Self frame is used as a frame for protecting subsequent signals from interference, similar to the RTS / CTS exchange. In this processing example, the CTS-to-Self frame may be used to prohibit other communication devices from transmitting on the PCH. Furthermore, compared to RTS / CTS exchange, when a CTS-to-Self frame is used, channel reservation is completed by transmitting one frame, and therefore reception processing at AP 101 is not required.The communication devices 100 (STA103, AP111, STA112, etc.) that receive a reservation signal including a channel reservation period set NAV702 to the PCH. When NAV702 expires, each communication device 100 determines that the PCH is available and starts a channel access procedure. For example, at time t5, STA103 acquires the transmission right and transmits a data frame 703 addressed to AP101 by channel bonding using the PCH and NPCH.

[0041] In the time chart of FIG. 7, the operation flow executed by the AP 101 is shown in FIG. 8. As in FIG. 6, this is applicable to the communication device 100 including the STA 102, and therefore, hereinafter, the operation of the communication device 100 will be described. The same reference numbers are given to the same operations as in FIG. 6, and the description will be omitted. First, the communication device 100 executes carrier sense in the PCH according to the procedure of S601 to S604. If the NAV is set by the OBSS signal in the PCH (NO in S602), the communication device 100 continues to execute carrier sense in the SPCH. If a signal is detected in the SPCH (YES in S605), the communication device 100 executes reception processing of this signal. Also, while executing this reception processing, the communication device 100 executes monitoring of the PCH in parallel. If the NAV set in the PCH ends before the reception processing is completed (YES in S608), the communication device 100 transmits a signal to suppress transmission of the PCH (S801). The communication device 100 may determine the period during which the transmission of the PCH is suppressed based on the TXOP period in the NPCH access, and may suppress the transmission of the PCH over that period. For example, the communication device 100 may set the value of the Duration field included in the CTS-to-Self frame so that the end of the period during which the transmission of the PCH is suppressed coincides with the expiration of the TXOP period in the NPCH access. By aligning the end of the period during which the transmission of the PCH is suppressed with the expiration of the TXOP period in the NPCH access, the possibility of performing channel bonding using both the PCH and the NPCH at the next transmission opportunity increases. In addition, the communication device 100 may set the period during which the transmission of the PCH is suppressed to be longer than the expiration of the TXOP period in the NPCH access, taking into consideration the time required for the AP 101, the STA 102, etc. to switch from communication using the NPCH access to communication using the PCH. When a certain period is required for the communication device 100 to switch the communication method used for communication, it may be possible to ensure that the communication device that performed the NPCH access and other communication devices can access the channel fairly.In this way, the end of the period during which transmission in the PCH is suppressed and the expiration of the TXOP period in the NPCH access do not necessarily have to be simultaneous, and there may be a certain difference within a range that does not hinder channel bonding using both the PCH and the NPCH at the next transmission opportunity. When the communication device 100 completes the signal reception process by the NPCH access (NO in S608, YES in S607), it continues carrier sense of the SPCH until the NAV of the PCH expires (S606). When the NAV of the PCH expires, the communication device 100 returns to S601 and continues the process.

[0042] In the above, an example has been described in which the communication device 100 transmits a CTS-to-Self frame in the PCH when the PCH becomes available, but the signal for suppressing transmission in the PCH is not limited to the CTS-to-Self frame. The AP 101 may execute RTS / CTS exchange in the PCH. For example, the AP 101 may execute RTS / CTS exchange in the PCH with the STA 102 communicating in the NPCH. The AP 101 may also execute RTS / CTS exchange with other STAs connected to the own device. The RTS / CTS exchange enables suppression of transmission in the PCH over a wider geographical range than when the CTS-to-Self frame is used. The AP 101 may also determine whether or not to transmit a CTS-to-Self frame, etc., based on interference with NPCH access caused by the transmission power in the PCH. For example, the AP 101 may determine to transmit a CTS-to-Self frame, etc., in the PCH when the interference power caused in the NPCH when transmission is performed in the PCH is smaller than a threshold value. On the other hand, when the interference power occurring in the NPCH when transmitting in the PCH is greater than a threshold, the AP101 may start an operation for receiving a new signal in the PCH without transmitting a CTS-to-Self frame. This allows the AP101 to receive a signal addressed to the AP101 in the PCH even if the AP101 cannot suppress transmission of other communication devices in the PCH. Note that, in FIG. 7, an example in which the AP101 receives a signal has been described. However, when the AP101 transmits a signal to the STA102 by NPCH access, the influence of interference occurring in the NPCH is small even if the AP101 transmits a signal in the PCH during the transmission. Therefore, when the AP101 determines that the PCH has become available while transmitting a signal by NPCH access, the AP101 may transmit a CTS-to-Self frame to the PCH regardless of the magnitude of interference between the NPCH and the PCH. That is, the AP101 may determine whether the AP101 is transmitting or receiving using the NPCH access, and may transmit a CTS-to-Self frame to the PCH based on the result.

[0043] As described above, in this processing example, the communication device 100 performing communication by NPCH access determines in parallel whether the PCH becomes available, and when the PCH becomes available, suppresses the transmission of signals by other communication devices in the PCH. This makes it possible to prevent, for example, a signal addressed to the communication device communicating by NPCH access from being transmitted in the PCH. In addition, by aligning the end of the period during which the transmission in the PCH is suppressed with the end of the communication by NPCH access, the possibility of performing channel bonding using both the PCH and NPCH at the next transmission opportunity is increased, and frequency resources can be used efficiently.

[0044] [Processing example 3] In this processing example, the operation of the AP 101 will be described using an example in which the AP 101 performing communication by NPCH access performs control to terminate NPCH access when the AP 101 determines that the PCH has become available. FIG. 9 shows an example of a time chart relating to signals exchanged in the PCH, NPCH, and other links in this processing example. The same reference numbers are given to operations similar to those in FIG. 5, and descriptions are omitted. At time t3, the AP 101 receives a CF-END frame 509 in the PCH, thereby determining that the PCH has become available. Then, at time t4, the AP 101 transmits a notification signal 901 indicating that the PCH has become available to the STA 102 performing transmission by NPCH access. For example, when the AP 101 and the STA 102 establish a multi-link and perform communication, the AP 101 may transmit the notification signal 901 using a link other than the link performing communication by NPCH access. Upon receiving the notification signal 901, the STA 102 transmits a CF-END frame 902 that cancels the NAV 508 set in the NPCH without transmitting a data frame that was scheduled to be transmitted (for example, data frame 506 in FIGS. 5 and 7). This makes the NPCH available for use. For example, if data addressed to the AP 101 is stored in the transmission buffer of the STA 103 at time t6, the STA 103 performs carrier sense on the PCH and transmits a data frame 903 by channel bonding using the PCH and NPCH.

[0045] In the time chart of FIG. 9, the operation flow executed by the AP 101 is shown in FIG. 10. The same reference numbers are given to operations similar to those in FIG. 6, and the description is omitted. In the following, the operation flow is described as the operation of the AP 101, but this operation flow is also applicable to the communication device 100 including the STA 102. First, the AP 101 executes carrier sense in the PCH according to the procedure of S601 to S604. When the NAV is set by the OBSS signal in the PCH (NO in S602), the AP 101 executes carrier sense in the SPCH. When the AP 101 detects a signal in the SPCH (YES in S605), the AP 101 executes reception processing of this signal. In addition, while executing this reception processing, the AP 101 executes monitoring of the PCH in parallel. When the NAV set in the PCH ends before the reception processing is completed (YES in S608), the AP 101 transmits a notification signal indicating that the PCH has become available (S1001). The AP101 may transmit a signal instructing the end of transmission in the NPCH instead of a notification signal indicating that the PCH has become available. When the STA102 receives a notification signal indicating that the PCH has become available, the STA102 may determine whether or not to end the NPCH access based on the type of data being transmitted by the NPCH access. For example, when the data being transmitted by the STA102 is data with a delay request, the STA102 may continue the NPCH access as is. On the other hand, when the STA102 is instructed to end the transmission in the NPCH, the STA102 may end the NPCH access according to the instruction. When the signal reception process by the NPCH access is completed (NO in S608, YES in S607), the AP101 continues the carrier sense of the SPCH until the NAV of the PCH expires (S606). When the NAV of the PCH expires, the AP101 returns to S601 and continues the process.

[0046] FIG. 11 shows an example of a notification signal indicating that the communication device 100 has entered a state in which the PCH is available. FIG. 11(A) shows an example of a notification signal when a notification is made using a control frame. The control frame 1100 in FIG. 11(A) may be called an Extended CF-END frame. The control frame 1100 may be called by another name. The control frame 1100 includes a Frame Control field 1101, a Duration field 1102, an RA field 1103, a BSSID field 1104, and a Link ID field 1105. RA is an abbreviation for Receiver Address. The Frame Control field 1101 includes information on frame control. For example, the Frame Control field 1101 includes information such as a frame type and subtype. As an example, in the case of an Extended CF-END frame, the frame type may be Control, and the subtype may be Extended CF-END. The Duration field 1102 indicates, for example, an estimate of the time required to transmit this frame and the time required for the response and frame interval. The RA field 1103 indicates address information of the communication device 1103 that should receive this frame. For example, the RA field 1103 may store the address of a communication device with which the communication device 100 transmitting this frame is communicating by NPCH access on another link. The BSSID field 1104 indicates an identifier of a BSS to which the communication device 100 transmitting this frame belongs, or the address of the communication device 100 transmitting this frame. The Link ID field 1105 indicates information that can identify a link in which the PCH has transitioned from a busy state to a usable state. The communication device 100 that has received the control frame 1100 knows that the PCH has become usable on one of the links because the Frame Control field 1101 indicates that the frame is an Extended CF-END frame. The communication device 100 also knows which link the PCH has become usable on by the Link ID field 1105.

[0047] FIG. 11B shows an example of a notification signal when a notification is made using an Action frame including a predetermined Action field. The Action field 1110 in FIG. 11B may be called a CF-END Notification Action field. The Action field 1110 may be called by another name. The Action field 1110 includes a Category field 1111, a Protected UHR Action field 1112, and a Link ID field 1105. The Category field 1111 indicates the category of this Action field. For example, the Category field 1111 stores an identification number corresponding to Protected UHR. The Protected UHR Action field 1112 indicates an identifier of this Action field in the category of Protected UHR. For example, the Protected UHR Action field 1112 stores an identification number indicating the CF-END Notification Action field. The Link ID field 1105 indicates information that can identify a link in which a PCH has transitioned from a busy state to an available state, as in FIG. 11A. The communication device 100 knows that the PCH has become available in any of the links because the Protected UHR Action field 1112 is a CF-END Notification Action field. Also, the communication device 100 knows in which link the PCH has become available, based on the Link ID field 1105.

[0048] When the link in which the PCH has become available matches the link on which the communication device 100 is executing the NPCH access, the communication device 100 determines whether or not to terminate this NPCH access. Note that the control frame 1100 or the Action field 1110 may be transmitted to instruct the termination of the NPCH access on the link indicated by the Link ID 1105. In this case, the communication device 100 that has received the control frame 1100 or the Action field 1110 terminates the NPCH access in accordance with this instruction.

[0049] In the above, an example has been described in which the AP 101 notifies the STA 102 using another link when the PCH becomes available, but the method in which the AP 101 notifies or instructs the STA 102 is not limited to this. For example, the AP 101 may notify or instruct the STA 102 using an ACK 505 for a data frame 504 received in the NPCH. This makes it possible to execute such notifications and instructions even between communication devices that are not performing multi-link communication. FIG. 11C shows another example of a notification signal when a notification is made using a control frame. The control frame 1120 in FIG. 11C may be called an Extended ACK frame. The control frame 1120 may be called by another name. The control frame 1120 includes a Frame Control field 1101, a Duration field 1102, an RA field 1103, and a Link ID field 1105. The same reference numbers are given to the same configurations as those in FIG. 11C, and descriptions thereof will be omitted. The subtype included in the Frame Control field 1101 in the Extended ACK frame may be Extended ACK. The communication device 100 that has received the control frame 1120 knows that the PCH has become available in one of the links because the Frame Control field 1101 indicates that the control frame is an Extended ACK frame. The communication device 100 also knows, from the Link ID field 1105, in which link the PCH has become available.

[0050] In FIG. 9, an example in which the AP 101 receives a signal by NPCH access has been described, but when the AP 101 transmits a signal to the STA 102 by NPCH access, the AP 101 may autonomously terminate the NPCH access. For example, when the AP 101 determines that the PCH has become available while performing NPCH access, the AP 101 may transmit a CF-END without transmitting a data frame that was scheduled to be transmitted thereafter. By the communication device transmitting the NPCH access terminating the NPCH access in accordance with the PCH status, the possibility of performing channel bonding using both the PCH and NPCH at the next opportunity increases. This makes it possible to efficiently utilize frequency resources.

[0051] As described above, in this processing example, the communication device 100 performing communication by NPCH access determines in parallel whether the PCH becomes available, and executes control to terminate the NPCH access when the PCH becomes available. This increases the possibility that channel bonding using both the PCH and NPCH will be possible at the next transmission opportunity, and makes it possible to use frequency resources efficiently.

[0052] As described above, according to the present embodiment, even if the PCH is unavailable, communication using the NPCH is performed based on carrier sense in the SPCH. This allows efficient use of the link frequency, and increases the communication capacity provided by the wireless communication system. Also, according to the present embodiment, when the PCH becomes available during communication by NPCH access, control for communication using the PCH is performed. This allows signals transmitted in the PCH to be received normally. Furthermore, according to some embodiments, by controlling the timing at which the PCH and NPCH become available, the possibility of performing channel bonding using the PCH and NPCH at the next transmission opportunity is increased. This allows efficient use of frequency resources.

[0053] The present technology may also be applied between a plurality of STAs. In addition, in the present embodiment, a case where a communication method that does not use a PCH is called NPCH access is illustrated, but the present invention is not limited thereto, and may be referred to as, for example, Secondary Primary channel access. In the present embodiment, a case where a channel for determining whether or not transmission using an NPCH is possible is illustrated as SPCH for convenience, but the present invention is not limited thereto. Among a plurality of secondary channels, a channel having a high priority for determining whether or not transmission is possible may be referred to as PSCH (Primary Secondary Channel). Regardless of which term is used, it means that the channel should be used to determine whether or not transmission using an NPCH is possible. In addition, the names of the information elements and various fields in the present embodiment may be referred to by other names. Note that the operations of the communication device 100 in each of the above-mentioned processing examples may be executed in combination with each other. For example, when the interference power generated in the NPCH due to the transmission of a signal in the PCH is smaller than a threshold value, the communication device 100 that has determined that the PCH is available may transmit a reservation signal to the PCH. On the other hand, when the interference power caused in the NPCH by the transmission of a signal in the PCH is greater than the threshold, the communication device 100 that has determined that the PCH is available may execute a receiving operation for receiving a signal addressed to the device itself without transmitting a reservation signal to the PCH. Also, when it has determined that the PCH is available, the communication device 100 may instruct the other communication device to end NPCH access while transmitting a reservation signal to the PCH. In this case, the communication device 100 may transmit a CF-END for canceling the NAV set in the NPCH by the reservation signal in response to receiving a CF-END for canceling the NAV set in the NPCH.

[0054] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0055] (Summary of the embodiment) (Item 1) A communication device that performs communication in accordance with the IEEE 802.11 series standard, a communication means for performing communication with a first communication device by a first communication method using one or more channels including a first channel used for acquiring a transmission right and one or more second channels different from the first channel, and a second communication method using one or more of the second channels when the first channel is unavailable; a detection means for detecting whether the first channel is available during a period in which the communication device is communicating with the first communication device in the second communication method; and a control means for executing control for communication using the first channel when the first channel becomes available during a period in which communication is being performed using the second communication method. A communication device comprising: (Item 2) The detection means detects that the first channel has become available when a completion signal terminating a Network Allocation Vector set for the first channel is detected. 2. The communication device according to item 1, (Item 3) The detection means detects the completion signal transmitted using a CF (Contention Free)-END frame defined in the IEEE 802.11 series standard. 3. The communication device according to item 2, (Item 4) The control means controls the communication means to receive a signal addressed to the communication device and transmitted on the first channel by a second communication device different from the first communication device while the communication device is receiving a signal from the first communication device in the second communication method. 4. The communication device according to any one of items 1 to 3, (Item 5) The control means, as the control, causes the communication means to transmit a signal to a second communication device different from the first communication device on the first channel while the communication device transmits a signal to the first communication device in the second communication method. 5. The communication device according to any one of items 1 to 4, (Item 6) The control means transmits a reservation signal for reserving the first channel as the control. 6. The communication device according to any one of items 1 to 5, (Item 7) The communication device described in item 6, wherein the reservation signal includes a reservation period for the first channel that is set based on a period during which the communication device is communicating with the first communication device using the second communication method. (Item 8) 7. The communication device according to item 6, wherein the reservation signal is a CTS (Clear-to-Send)-to-Self frame defined in the IEEE 802.11 series standard. (Item 9) the control means, as the control, causes the communication means to transmit, to the first communication device, a notification that the first channel has become available or an instruction to end transmission by the second communication method while the communication device is receiving a signal from the first communication device by the second communication method; 9. The communication device according to any one of items 1 to 8, (Item 10) The control means causes the communication means to transmit the notification or the instruction using a response to a signal from the first communication device. 10. The communication device according to item 9, (Item 11) The control means causes the communication means to transmit the notification or the instruction using a communication link different from the communication link. 10. The communication device according to item 9, (Item 12) the control means controls the communication means so as to terminate transmission of a signal to the first communication device in the second communication method while the communication device is transmitting a signal to the first communication device in the second communication method; 12. The communication device according to any one of items 1 to 11, (Item 13) A communication method executed by a communication device capable of performing communication in compliance with the IEEE 802.11 series standard with a first communication device by a first communication method using one or more channels including a first channel used for acquiring a transmission right and one or more second channels different from the first channel, and a second communication method using one or more of the second channels when the first channel is unavailable, comprising: a detection step of detecting whether the first channel has become available during a period in which the communication device is communicating with the first communication device in the second communication method; and a control step of executing control for communication using the first channel when the first channel becomes available during a period in which communication is being performed using the second communication method. A communication method comprising: (Item 14) A computer is provided in a communication device capable of performing communication in compliance with the IEEE 802.11 series standard with a first communication device by a first communication method using one or more channels including the first channel, and a second communication method using one or more of the second channels when the first channel is unavailable, in one communication link composed of a first channel used to acquire a transmission right and one or more second channels different from the first channel, detecting whether the first channel has become available during a period in which the communication device is communicating with the first communication device in the second communication method; When the first channel becomes available during a period in which communication is being performed according to the second communication method, control is executed for communication using the first channel. Program for.

[0056] The invention is not limited to the above-described embodiments, and various modifications and variations are possible 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]

[0057] 10:Network, 101:AP, 102:STA, 103:STA, 11:Network, 111:AP, 112:STA

Claims

1. A communication device that performs communication in accordance with the IEEE 802.11 series standard, a communication means for performing communication with a first communication device by a first communication method using one or more channels including a first channel used for acquiring a transmission right and one or more second channels different from the first channel, and by a second communication method using one or more of the second channels when the first channel is unavailable; a detection means for detecting whether the first channel has become available during a period in which the communication device is communicating with the first communication device in the second communication method; and a control means for executing control for communication using the first channel when the first channel becomes available during a period in which communication is being performed using the second communication method. A communication device comprising:

2. The detection means detects that the first channel has become available when it detects a completion signal that terminates a Network Allocation Vector set in the first channel.

2. The communication device according to claim 1 .

3. The detection means detects the completion signal transmitted using a CF (Contention Free)-END frame defined in the IEEE 802.11 series standard.

3. The communication device according to claim 2.

4. The control means controls the communication means to receive a signal addressed to the communication device and transmitted on the first channel by a second communication device different from the first communication device while the communication device is receiving a signal from the first communication device in the second communication method.

2. The communication device according to claim 1 .

5. The control means, as the control, causes the communication means to transmit a signal to a second communication device different from the first communication device on the first channel while the communication device transmits a signal to the first communication device in the second communication method.

2. The communication device according to claim 1 .

6. The control means transmits a reservation signal for reserving the first channel as the control.

2. The communication device according to claim 1 .

7. The communication device according to claim 6 , wherein the reservation signal includes a reservation period for the first channel that is set based on a period during which the communication device is performing communication with the first communication device using the second communication method.

8. 7. The communication device according to claim 6, wherein the reservation signal is a CTS (Clear-to-Send)-to-Self frame defined in the IEEE 802.11 series standards.

9. the control means, as the control, causes the communication means to transmit, to the first communication device, a notification that the first channel has become available or an instruction to end transmission by the second communication method, while the communication device is receiving a signal from the first communication device by the second communication method; 2. The communication device according to claim 1 .

10. the control means causes the communication means to transmit the notification or the instruction using a response to a signal from the first communication device; 10. The communication device according to claim 9 .

11. The control means causes the communication means to transmit the notification or the instruction using a communication link different from the communication link.

10. The communication device according to claim 9 .

12. the control means controls the communication means so as to terminate transmission of a signal to the first communication device in the second communication method while the communication device is transmitting a signal to the first communication device in the second communication method; 2. The communication device according to claim 1 .

13. A communication method executed by a communication device capable of performing communication in accordance with the IEEE 802.11 series standard with a first communication device by a first communication method using one or more channels including a first channel used for acquiring a transmission right and one or more second channels different from the first channel, and a second communication method using one or more of the second channels when the first channel is unavailable, comprising: a detection step of detecting whether the first channel has become available during a period in which the communication device is communicating with the first communication device in the second communication method; and a control step of executing control for communication using the first channel when the first channel becomes available during a period in which communication is being performed using the second communication method. A communication method comprising:

14. A computer is provided in a communication device capable of performing communication in accordance with the IEEE 802.11 series standard with a first communication device by a first communication method using one or more channels including the first channel and a second communication method using one or more of the second channels when the first channel is unavailable, in one communication link composed of a first channel used to acquire a transmission right and one or more second channels different from the first channel, detecting whether the first channel has become available during a period in which the communication device is communicating with the first communication device in the second communication method; When the first channel becomes available during a period in which communication is being performed according to the second communication method, control is executed for communication using the first channel. Program for.

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