Communication device, control method, and program

Abstract

To improve the efficiency in using channels in a communication system that uses a communication link comprising a plurality of channels.SOLUTION: In one communication link comprising a first channel used for acquiring a transmission right, and one or more second channels different from the first channel, a communication device can perform communication with another communication device by 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 cannot be used. The communication device has: notification means that notifies the other communication device having a function that can execute communication using second communication method, of first information that can be used by the other communication device to determine whether it can execute the communication using the second communication method; and communication means that, on the basis of the first information, performs data communication with the other communication device connected to the communication device by using one or more channels including either one of the first channel or the second channel.SELECTED DRAWING: Figure 3

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 capable of communicating with other communication devices in a single communication link consisting of a first channel used to acquire a transmission right and one or more second channels different from the first channel, using 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, and has a notification means for notifying the other communication device having a function capable of performing communication using the second communication method of first information that can be used by the other communication device to determine whether or not it is permitted to perform communication using the second communication method, and a communication means for communicating data with the other communication device connected to the communication device using one or more channels including either the first channel or the second channel based on the first information. 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] 13 is a diagram showing an example of a flow when an AP notifies a STA of whether or not NPCH access can be performed. [Figure 4] FIG. 13 is a diagram illustrating an example of an NPCH Access element. [Diagram 5] FIG. 13 is a diagram illustrating an example of an NPCH Operating Mode Notification frame Action field. [Figure 6] FIG. 11 is a diagram showing an example of a flow for determining whether NPCH access can be performed. [Figure 7] 10 is an example of a flowchart showing a flow of channel access by a communication device. [Figure 8] 1 is an example of a sequence executed between communication devices. [Figure 9] FIG. 11 is a diagram showing an example of a flow for determining a condition for whether or not NPCH access can be performed. [Figure 10] FIG. 13 is a diagram illustrating an example of an NPCH Access element. [Figure 11] 10 is an example of a flowchart showing a flow of channel access by a communication device. [Figure 12] FIG. 11 is a diagram showing an example of a flow for determining whether NPCH access can be performed. [Figure 13] FIG. 2 illustrates an example of a hardware configuration of a communication device. [Figure 14] FIG. 2 illustrates an example of a functional configuration of a communication device. 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 a station (STA) 102. The AP 101 and the STA 102 are communication devices capable of performing wireless communication conforming to the IEEE 802.11 series standard. In this embodiment, the AP 101 and the STA 102 may be collectively referred to as a communication device 100. IEEE is an abbreviation for the Institute of Electrical and Electronics Engineers. FIG. 1 shows a configuration in which the STA 102 participates in a network 103 constructed by the AP 101. The network 103 may also be called a Basic Service Set (BSS). In FIG. 1, a configuration in which one AP 101 and one STA 102 exist is shown, but there may be a plurality of APs and a plurality of STAs. In addition, at that time, a plurality of STAs may be connected to one AP, and one STA may be connected to a plurality of APs. 1, a network 113 consisting of AP 111 and STA 112 exists near a network 103 consisting of AP 101 and STA 102. AP 111 and STA 112 are communication devices capable of performing wireless communication conforming to the IEEE802.11 series standard, similar to AP 101 and STA 102. For AP 101 and STA 102, network 103 is a BSS to which the own devices are connected, and may be called their own BSS. On the other hand, for AP 101 and STA 102, network 113 is a network that may cause interference to their own BSS, and may be called an overlapping BSS (OBSS).

[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 standard to the IEEE 802.11be standard that targets a maximum transmission speed of 46.08 Gbps (Giga bit per second). The main feature of the IEEE 802.11bn 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 of UHR, IEEE 802.11bn, etc. may be changed to other names when the formulation of the standard is completed. It should be noted that the present 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 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 compatible with the IEEE802.11bn standard or the like.The STA 102 is, for example, but 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 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 channel in combination with another adjacent channel. Such use of a 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, a signal transmitted in this bandwidth may be continuous or discontinuous on the frequency axis. The AP 101 and the STA 102 may be an AP MLD (Multi-Link Device) and a STA MLD, respectively, that are compatible with Multi-Link, which establishes multiple links simultaneously to communicate.

[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 sense). The received signal strength may also be called a Received Signal Strength Indicator (RSSI). The communication device 100 may also determine whether a signal is present 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 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 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 113 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 AP101 and the STA102 communicate using a first communication method using one or more channels including the PCH and a second communication method (NPCH access) using one or more NPCHs not including the PCH. For example, the AP101 and the STA102 have 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. The PCH and the NPCH may be called the first channel and the second channel, respectively. Here, even if the PCH cannot be used, it may be more efficient not to perform NPCH access and to postpone transmission until the PCH can be used. For example, if congestion occurs in the NPCH, the probability of communication by the NPCH access being unavailable is high. In such a situation, it may be more efficient to perform a power saving operation without attempting NPCH access. In this embodiment, a technique is provided that enables the AP101 and the STA102 to dynamically control whether or not to actually perform communication by the NPCH access in a situation in which the communication can be performed.

[0019] (Example of processing executed in AP101 and STA102) Hereinafter, some examples of the flow of processes executed by the AP 101 and the STA 102 in this embodiment will be described.

[0020] [Processing example 1] (Notification of information regarding NPCH access) In this embodiment, the AP 101 judges whether or not to execute NPCH access, and notifies the STA 102 of information indicating whether or not NPCH access is executable based on the judgment result. Then, the AP 101 and the STA 102 decide the communication method to be used in communication based on the judgment result. As an example, the AP 101 may transmit a notification that NPCH access is executable when executing NPCH access can improve the efficiency of the entire system, and may transmit a notification that execution of NPCH access is not permitted in other cases. This can prevent the AP 101 and the STA 102 from attempting NPCH access when execution is not appropriate. The AP 101 may adopt various standards to improve the efficiency of the entire system. For example, when the PCH or NPCH is congested, there is a possibility that the transmission right cannot be acquired even if NPCH access is attempted. In this case, it can be said that it is more efficient in terms of energy consumption to wait while performing power saving operation until the PCH becomes idle without attempting NPCH access. On the other hand, when transmitting traffic with a delay request, delay characteristics can be improved by actively attempting NPCH access. Moreover, if traffic without a delay request is not permitted to execute NPCH access, the possibility of collision occurring with traffic with a delay request can be reduced, and the probability of successful transmission of traffic with a delay request can be improved. Furthermore, in order to efficiently use NPCH access, only communication terminals with high communication quality may be permitted to access NPCH, thereby increasing the success rate of NPCH access in the entire system. Furthermore, efficiency can be improved by combining with other functions such as multi-link communication. The criteria by which the AP101 determines whether or not to execute NPCH access are not limited to these, and the present technology can be used for various applications that can be provided by dynamically switching whether or not to execute NPCH access. In the following description, an example is shown in which the AP101 notifies the STA102 of whether or not to execute NPCH access, but the STA102 may notify the AP101. Furthermore, unless there is a contradiction, all of the processes described as being executed by the AP101 in the following description may be executed by the STA102.

[0021] FIG. 3 shows a flow when the AP 101 notifies the STA 102 of whether or not to execute NPCH access. First, the AP 101 decides whether or not to permit execution of NPCH access (S301). The operation of the AP 101 regarding the determination of permission of execution of NPCH access will be described later. When the execution of NPCH access is permitted (YES in S301), the AP 101 notifies the STA 102 of information indicating that execution of NPCH access is permitted (described later) (S302). In this case, the AP 101 and the STA 102 execute either communication using the PCH or communication using the NPCH access based on the result of carrier sense in the PCH. For example, when the PCH is in an idle state (YES in S303), the AP 101 and the STA 102 execute communication using the PCH (S305). On the other hand, when the PCH is not in an idle state (NO in S303), the AP 101 and the STA 102 execute communication using the NPCH access (S304).

[0022] In S301, if the AP 101 does not permit the execution of NPCH access (NO in S301), the AP 101 notifies the STA 102 of information indicating that the execution of NPCH access is not permitted (S302). In this case, the AP 101 and the STA 102 execute communication using the PCH (S305).

[0023] FIG. 4 shows an example of an information element for the AP 101 to notify the STA 102 of whether or not NPCH access can be performed. This information element may be called an NPCH Access element. This information element may be called by other names. The AP 101 notifies the STA 102 of whether or not NPCH access can be performed, for example, by storing the NPCH Access element in a Beacon frame and transmitting it. By notifying whether or not NPCH access can be performed using a Beacon frame, it is possible to notify all STAs connected to the AP 101 at once. The NPCH Access element includes an Element ID field 401, a Length field 402, an Extended Element ID field 403, and an NPCH Access Control field 404. The NPCH Access element may also include an NPCH Access Parameter Update field 405 as an option. The combination of the Element ID field 401 and the Extended Element ID field 403 indicates the type of element. For example, the Element ID field 401 may store a value of 255, and the Extended Element ID field 403 may store a value associated with the NPCH Access element. The Length field 402 indicates the length of this element.

[0024] The NPCH Access Control field 404 includes an NPCH Access Mode field 406 and an NPCH Access Parameter Update Control field 407. The NPCH Access Mode field 406 indicates whether or not NPCH access is executable. For example, when the AP 101 permits execution of NPCH access, it stores 1 in this field. On the other hand, when the AP 101 prohibits execution of NPCH access, it stores 0 in this field. The STA 102 may determine whether or not NPCH access is permitted or prohibited by, for example, acquiring the value of the NPCH Access Mode field 406 included in the Beacon frame. Note that the method of indicating whether or not NPCH access is executable is not limited to this method. For example, it may be indicated that NPCH access is executable by a value of a field related to NPCH access, such as the NPCH Access Parameter Update field 405 described later, being non-zero. The NPCH Access Parameter Update Control field 407 indicates the presence or absence of the NPCH Access Parameter Update field 405. For example, when the NPCH Access element includes the NPCH Access Parameter Update field 405, 1 is stored in this field. On the other hand, if the NPCH Access element does not include the NPCH Access Parameter Update field 405, then 0 is stored in this field.

[0025] The NPCH Access Parameter Update field 405 includes a Secondary Primary Channel Number field 408 and an NPCH Access Transition Delay field 409. The Secondary Primary Channel Number field 408 indicates information capable of identifying an NPCH (i.e., an SPCH) on which carrier sense should be performed when the STA 102 performs an NPCH access. For example, the Secondary Primary Channel Number field 408 stores a channel number of an SPCH. The STA 102 can grasp a channel on which carrier sense should be performed when the STA 102 performs an NPCH access by acquiring a value of the Secondary Primary Channel Number field 408. The method of specifying the SPCH is not limited to the channel number of the SPCH, and may be, for example, information indicating a relative position of the SPCH on the frequency axis based on the PCH. Note that, when there are multiple SPCHs, the AP 101 may provide multiple Secondary Primary Channel Number fields 408. In this case, the AP 101 may notify the priority order for performing carrier sense assigned to each SPCH. By notifying the priority order for performing carrier sense, even if multiple SPCHs are set, it becomes possible to perform NPCH access while synchronizing between the AP 101 and the STA 102. The AP 101 may also provide a field for storing information indicating the priority order for each SPCH, and may determine the location for arranging the SPCH information according to the priority order. For example, the AP 101 may arrange information related to an SPCH with a higher priority order closer to the beginning of the field.

[0026] The NPCH Access Transition Delay field 409 indicates the switching time required for the AP 101 to switch the channel on which carrier sense is performed. For example, the NPCH Access Transition Delay field 409 is configured with 3 bits, and when the value is 0, 1, 2, 3, 4, or 5, the switching time is 0, 16, 32, 64, 128, or 256 μsec, respectively. The STA 102 may obtain the value of the NPCH Access Transition Delay field 409 included in the Beacon frame and switch the channel on which carrier sense is performed in accordance with the operation of the AP 101. For example, when the STA 102 detects that the PCH is busy, the STA 102 may start carrier sense in the SPCH after the switching time has elapsed. In this way, when the AP 101 indicates whether or not NPCH access can be performed, the STA 102 may also notify information to be used by the STA 102 for NPCH access, so that the STA 102 that has determined that NPCH access can be performed can quickly perform NPCH access. When the value of the NPCH Access Mode field 406 is 0, the Secondary Primary Channel Number field 408 and the NPCH Access Transition Delay field 409 may be omitted. Also, if any parameter does not need to be updated, the field corresponding to that parameter may be omitted.

[0027] Furthermore, the AP 101 may use an Action frame to notify the STA 102 of whether or not NPCH access can be performed. By using the Action frame, it is possible to notify the STA 102 of the determination of whether or not NPCH access can be performed made by the AP 101 in a timely manner. Furthermore, if the determination of whether or not NPCH access can be performed is not performed frequently, it is not efficient to continue notifying the determination result by a Beacon frame that is periodically transmitted. By using an Action frame instead of a Beacon frame, it is possible to transmit only when a determination is made or when the determination result of whether or not NPCH access can be performed is different from the previous determination result. Furthermore, by using an Action frame, it is possible to individually adjust parameters to be used for NPCH access for each STA.

[0028] FIG. 5 shows an example of an Action field for notifying whether NPCH access can be performed. This field may be called an NPCH Operating Mode Notification frame Action field. This field may be called by other names. This field includes a Category field 501, a Protected UHR Action field 502, a Dialog Token field 503, and an NPCH Access Control field 404. The NPCH Operating Mode Notification frame Action field may also include an NPCH Access Parameter Update field 405. Here, in FIG. 5, the same reference numbers are used for fields having the same roles as those in FIG. 4, and descriptions thereof will be omitted. The Category field 501 indicates the category of this Action field. For example, the Category field 501 stores an identification number corresponding to Protected UHR. The Protected UHR Action field 502 indicates an identifier of this Action field in the category of Protected UHR. For example, the Protected UHR Action field 502 stores an identification number indicating the NPCH Operating Mode Notification frame Action field. The Dialog Token field 503 indicates an identifier for executing a series of information exchanges between the AP 101 and the STA 102. For example, an identifier assigned by the requesting communication device is stored in the Dialog Token field 503. The responding communication device stores the value included in the received Dialog Token field 503 in the Dialog Token field 503 of a response frame and transmits it.

[0029] The STA 102 may transmit a request for permission to execute NPCH access to the AP 101 using an Action frame or the like. For example, the Action frame for notifying this request may be called a Non-primary Channel Access Request frame. When the AP 101 receives the Non-primary Channel Access Request frame, it may determine whether or not to permit the STA 102, which is the sender, to execute NPCH access, and may notify the result of the determination. The Action frame for notifying the result of the determination may be called a Non-primary Channel Access Response frame. By exchanging these Action frames, the STA 102 may obtain permission to execute NPCH access based on a request from its own device. For example, when traffic with a delay request is stagnating in the transmission buffer of its own device, the STA 102 may actively request permission to execute NPCH access along with the situation.

[0030] (Determining whether NPCH access can be performed) As described above, the AP 101 determines whether or not to execute NPCH access prior to transmitting an NPCH Access element. Fig. 6 shows an operation flow when the AP 101 in this processing example determines whether or not to execute NPCH access. Note that this operation flow is processed by the AP 101 reading and executing a computer program stored in a storage unit 1301 (to be described later) by the control unit 1302 according to a communication procedure with the STA 102.

[0031] First, the AP 101 checks whether the STA 102 has a function to execute NPCH access through a connection procedure with the STA 102. For example, when the AP 101 starts a connection with the STA 102 (YES in S601), the AP 101 acquires capability information of the STA 102 from a Probe Request frame, an Association Request frame, or the like received from the STA 102 (S602). For example, the AP 101 may acquire the capability information of the STA 102 based on a Capabilities element included in these frames. Note that capability information regarding a function newly defined in the IEEE 802.11bn standard may be defined as a UHR Capabilities element. The AP 101 determines whether the STA 102 has a function to execute NPCH access based on the capability information acquired from the STA 102 (S603). If the STA 102 does not have a function to execute NPCH access (NO in S603), the AP 101 decides not to use NPCH access between the AP 101 and the STA 102 (S608). On the other hand, if the STA 102 has the function of executing NPCH access (YES in S603), the AP 101 stores the fact that NPCH access can be executed between the AP 101 and this STA 102.

[0032] Then, the AP 101 judges whether or not to permit the execution of NPCH access. Here, an example will be described in which the AP 101 judges whether or not to permit the execution of NPCH access based on the communication quality of the PCH, the communication quality of the NPCH, and the amount of communication traffic accumulated in the AP 101 and the STA 102. First, the AP 101 judges whether the communication quality of the PCH is equal to or higher than a threshold (S604). For example, the AP 101 measures a channel usage rate in the PCH and compares it with a predetermined threshold. As an example, when the measured channel usage rate exceeds a predetermined threshold, the AP 101 judges that the communication quality of the channel is lower than the threshold. The channel usage rate can be expressed by the ratio of time that the channel is in a busy state per unit time. When the communication quality of the PCH is equal to or higher than the threshold (YES in S604), the AP 101 decides not to execute the NPCH access (S608). On the other hand, if the communication quality of the PCH is lower than the threshold (YES in S604), the AP 101 compares the communication quality of the NPCH with a predetermined threshold (S605). If the communication quality of the NPCH is lower than the threshold (NO in S605), the AP 101 decides not to execute NPCH access (S608). On the other hand, if the communication quality of the NPCH is equal to or higher than the threshold (YES in S605), the AP 101 judges the accumulation status of communication traffic in the AP 101 and the STA 102 (S606). For example, the AP 101 may obtain the accumulation status of communication traffic in the STA 102 by requesting the STA 102 to notify the accumulation status of the transmission buffer. The AP 101 may also periodically calculate the total or average value of the amount of data accumulated in the AP 101 and the STA 102, and may determine that the amount of accumulated data is increasing if the change over time exceeds a predetermined threshold. If the amount of stored data has increased (YES in S606), AP101 decides that NPCH access is executable (S607). On the other hand, if the amount of stored data has not increased (NO in S606), AP101 decides not to execute NPCH access (S608). AP101 notifies STA102 of whether or not NPCH access can be executed. AP101 and STA102 then execute communication based on the decision made by AP101.

[0033] The method of AP101 determining whether or not to execute NPCH access is not limited to this example. As an example, in the example of FIG. 6, a case where both the communication quality of the PCH and the communication quality of the NPCH are used has been described, but AP101 may determine whether or not to execute NPCH access based on either the communication quality of the PCH or the communication quality of the NPCH. In order to evaluate the communication quality of the channel, for example, the channel usage rate is used. When the usage rate of the PCH is high because there are multiple other wireless networks using the same PCH as the network 103 in the vicinity, even if the busy PCH is waited until it becomes idle, it is not necessarily possible to obtain the transmission right at the next opportunity. Therefore, when the usage rate of the PCH is high, AP101 may determine that NPCH access should be executed. When the usage rate of the PCH is low, AP101 may determine that it should wait until the PCH becomes idle. On the other hand, when the usage rate of the NPCH is high, the NPCH is often busy, and there is a high possibility that NPCH access cannot be executed. Therefore, AP101 may determine that it should wait until the PCH becomes idle without performing NPCH access. During standby, power saving operation may be performed. Furthermore, when the usage rate of the NPCH is low, the AP 101 may determine that the NPCH access should be performed. By the AP 101 and the STA 102 performing the NPCH access, the transmission waiting time is reduced and the data transmission delay is alleviated. The communication quality of the channel may be the signal-to-interference-and-noise ratio (SINR), average throughput, average delay, etc. in the AP 101. Furthermore, the criterion for determining whether or not the AP 101 should perform the NPCH access is not limited to the communication quality between the PCH and the NPCH. For example, the AP 101 may determine whether or not the NPCH access should be performed based on the type of data (application, category, etc.) described later and the presence or absence of other functions such as multilink. The AP 101 may determine whether or not the NPCH access should be performed by combining the communication qualities of these channels and other criteria.

[0034] When the AP101 determines whether or not to perform NPCH access based on the communication quality of the channel, the AP101 executes a process for identifying the communication quality of the PCH or the NPCH. For example, the AP101 may identify the usage rate of the PCH based on the ratio of time during which the signal power exceeding a predetermined threshold per unit time is detected by monitoring the PCH. The AP101 may also identify the SINR from the RSSI of the signal received from the STA102 communicating with the AP101 and the RSSI of other signals (i.e., interference signals). Similarly, the AP101 may identify the communication quality in each of the NPCHs. Furthermore, the AP101 may cause the STA102 to measure the communication quality, obtain the result, and perform an analysis using the communication quality calculated by the AP101 and the communication quality obtained from the STA102 to identify the communication quality. As an example, the AP101 may request the STA102 to measure the communication quality of the SPCH. The STA102 may perform measurement of the communication quality of the SPCH based on the request from the AP101, and provide the measurement result to the AP101. For example, the AP 101 may request the STA 102 to perform measurement using a Measurement Request element. The Measurement Request element may include information for identifying the NPCH to be measured, items to be measured, a measurement period (measurement start time and measurement end time, etc.), the number of measurements, a measurement cycle, etc. For example, when multiple SPCHs are set in the NPCH, the AP 101 may specify whether all SPCHs are to be the targets of measurement, some SPCHs are to be the targets of measurement, or all NPCHs are to be the targets of measurement. For example, the AP 101 may specify the NPCH to be the target of measurement using a bitmap corresponding to each channel of the NPCH. In this case, a bit corresponding to the NPCH to be the target of measurement may be set to 1, and a bit corresponding to the NPCH not to be the target of measurement may be set to 0. The AP 101 may perform measurement to target all NPCHs and reconfigure the NPCH with high communication quality as the SPCH. On the other hand, when the target of measurement is limited, the load of the STA 102 performing the measurement is reduced. The STA 102 that performed the measurement may notify the AP 101 of the measurement result using, for example, a Measurement Report element.As an example, the Measurement Report may include information for identifying the NPCH on which the measurement was performed, the measurement result, the measurement period, the number of measurements, the measurement cycle, etc. The measurement item or the measurement result may be the channel usage rate, the SINR, etc. The method by which the AP 101 requests the STA 102 to measure the communication quality of the NPCH and the method by which the AP 101 obtains the measurement result are not limited to the above. In addition, the AP 101 may request the STA 102 to measure the communication quality of the PCH in the same way as the measurement of the communication quality of the NPCH.

[0035] The AP 101 may request the STA 102 to notify the STA 102 of the accumulated communication traffic status. The AP 101 may determine whether or not to execute NPCH access based on the accumulated communication traffic status of each STA 102. For example, the AP 101 may determine to execute NPCH access when the average value of the communication traffic accumulated in each STA 102 exceeds a predetermined threshold. By permitting communication by NPCH access, the AP 101 may cause the STA 102 to transmit the accumulated communication traffic early, thereby mitigating the deterioration of delay characteristics. The AP 101 may also permit NPCH access only to the STA 102 whose communication traffic exceeds the threshold. In this case, the AP 101 may notify each STA 102 of the NPCH Access element by using an Action frame.

[0036] (NPCH access via communication device) Based on the information on whether or not NPCH access can be performed notified from the AP 101, the STA 102 determines whether or not NPCH access can be performed, and communicates with the AP 101 using the first communication method or the second communication method. For example, the STA 102 acquires the value of the NPCH Access Mode field 406 included in the Beacon frame or Action frame received from the AP 101. If this value is 1, the STA 102 may determine that NPCH access is permitted to be performed, and if this value is 0, the STA 102 may determine that NPCH access is prohibited to be performed. In addition, the STA 102 acquires the values ​​of the Secondary Primary Channel Number field 408 and the NPCH Access Transition Delay field 409 included in the Beacon frame or the like. Based on these values, the STA 102 sets parameters to be used for NPCH access and communicates with the AP 101. Below, the operation of the communication device 100 in this embodiment when transmitting data will be described using the STA 102 as an example. This operation is not limited to the STA 102, but can also be applied to the AP 101.

[0037] FIG. 7 shows an example of a flow when the communication device 100 in this embodiment transmits data. When the STA100 detects that data has accumulated in a transmission queue provided in the own device (S701), the STA100 starts a channel access procedure to transmit the data. First, the STA102 performs carrier sense on the PCH (S702). For example, the STA102 measures a back-off counter in the PCH and determines whether the PCH is in an idle state. If the STA102 determines that the PCH is in an idle state (YES in S703), the STA102 transmits a signal using one or more channels including the PCH (S704). Note that the STA102 may perform carrier sense of the NPCH for a predetermined period after determining that the PCH is in an idle state. The STA102 may also perform carrier sense of the NPCH in parallel with carrier sense of the PCH. The STA102 may determine a channel to be used for transmission based on the results of carrier sense performed in each of the PCH and NPCH, and transmit a signal. For example, the STA 102 may transmit signals using the PCH and one or more NPCHs that it determines to be idle.

[0038] On the other hand, when the STA102 detects a signal on the PCH in the carrier sense (NO in S703), it sets the NAV for the PCH using the period indicated in the Duration field included in the received signal. Then, the STA102 checks whether or not the execution of the NPCH access is permitted. For example, when the execution of the NPCH access is prohibited (NO in S705), the STA102 waits until the PCH becomes idle (S706). On the other hand, when the execution of the NPCH access is permitted (YES in S705), the STA102 judges whether or not the signal detected on the PCH is transmitted from a communication device belonging to the network 103. For example, the STA102 may judge whether the signal is a signal from its own BSS or a signal from an OBSS based on whether or not the BSS Color field included in the received signal matches the BSS Color of its own BSS. Also, the STA102 may judge whether the signal is a signal from its own BSS or a signal from an OBSS based on whether or not the values ​​stored in the destination field, the source field, etc. included in the received signal match the parameters of its own BSS. For example, if the signal detected in the PCH is a signal from the OBSS (YES in S707), the STA 102 executes NPCH access. On the other hand, if the signal detected in the PCH is a signal from its own BSS (NO in S707), the STA 102 decides not to execute NPCH access and waits until the PCH becomes idle (S706).

[0039] When the STA 102 performs NPCH access, it performs carrier sense on the SPCH. When it does not detect a signal on the SPCH, the STA 102 measures a back-off counter in the same manner as the carrier sense on the PCH, and judges whether the SPCH is in an idle state or not. When it judges that the SPCH is in an idle state (YES in S708), the STA 102 transmits a signal using one or more NPCHs including the SPCH (S709). After it judges that the SPCH is in an idle state, the STA 102 may perform carrier sense on other NPCHs for a predetermined period. The STA 102 may determine a channel to be used for transmission based on the results of the carrier sense performed on the SPCH and the other NPCHs, and transmit a signal. On the other hand, when the STA 102 detects a signal on the SPCH (NO in S708), it stops the NPCH access and postpones transmission until the NAV period set on the PCH expires (S706). In addition, when multiple SPCHs are set, the STA102 may continue the NPCH access procedure until it is confirmed that all SPCHs are busy. If all SPCHs are busy, the STA102 postpones transmission until the NAV period set in the PCH expires. In addition, even if the execution of NPCH access is permitted, the STA102 may postpone transmission until the NAV period of the PCH expires without executing NPCH access. For example, the STA102 may postpone transmission until the NAV period of the PCH expires without executing NPCH access when the remaining battery level of the own device is below a threshold value or when the STA102 is set not to execute NPCH access by input from the user. In this case, the STA102 may perform a minimum reception operation required for transmission using NPCH access that can be executed by the AP101. For example, the STA102 may operate only a processing circuit that can only detect a received signal in the SPCH and operate other circuits in a power-saving manner.

[0040] FIG. 8 shows an example of a sequence between the AP 101 and the STA 102 in this embodiment. First, the AP 101 and the STA 102 execute a connection procedure (F801, F802). For example, an Association Request and an Association Response are exchanged between the devices. The Association Request and the Association Response include a UHR Capabilities element, and the capability information related to the NPCH access is shared with each other, completing the connection process (F803). The AP 101 and the STA 102 transmit and receive data based on the capability information of the NPCH access notified or acquired from each other and the determination of whether or not the NPCH access can be performed. For example, when the NPCH access is prohibited, the AP 101 and the STA 102 communicate using a first communication method including the PCH (F804, F805). On the other hand, when the NPCH access is permitted, the AP 101 and the STA 102 select the first communication method or the second communication method according to the PCH situation and communicate. For example, when NAV is set in the PCH, communication is performed using NPCH access (second communication method) (F806, F807).

[0041] Thus, in this embodiment, when AP 101 and STA 102 can communicate using NPCH access, AP 101 determines whether to execute NPCH access and notifies STA 102 of the determination result. Based on the notification, AP 101 and STA 102 determine whether to execute NPCH access and select a communication method to be used for communication. This makes it possible to execute efficient communication in terms of frequency resources, power consumption, etc., by using an appropriate communication method according to the wireless environment, etc., while determining whether to execute NPCH access.

[0042] [Processing example 2] In the processing example 1, the AP 101 judges whether or not NPCH access can be performed, and the STA 102 determines the communication method to be used in communication based on the result of the judgment. In this processing example, the AP 101 generates a condition to be satisfied when performing NPCH access, and notifies the STA 102. For example, the AP 101 may use, as the condition to be satisfied when performing NPCH access, that the traffic to be communicated corresponds to a predetermined type, that the communication quality of the channel used for NPCH access is equal to or higher than a predetermined threshold, and the like.

[0043] FIG. 9 shows an operation flow when the AP 101 in this processing example generates a condition to be satisfied when performing NPCH access and notifies the STA 102 of the condition. In the example shown in FIG. 9, the AP 101 enables NPCH access on the condition that the communication traffic has a predetermined delay request. That is, the AP 101 performs control so that the delay request of the data is satisfied even in a situation where the PCH is congested by permitting NPCH access for traffic with a delay request such as voice data and image data. Note that the traffic with a delay request may include time-critical data such as robot control, and data that affects the user experience such as print jobs and photo sharing. In the operation flow of FIG. 9, the same reference numbers are used for operations common to FIG. 6, and the description will be omitted. First, the AP 101 executes the procedure of S601 to S603 to confirm whether the STA 102 has a function to perform NPCH access. Then, the AP 101 determines whether the traffic to be communicated with the STA 102 includes traffic with a delay request (S901). For example, the AP 101 may determine whether traffic with a delay request is included based on an identifier (TID) indicating the type of traffic, an access category, or the like, assigned to the traffic communicating with the STA 102. The AP 101 may also determine whether the traffic has a delay request based on communication parameters exchanged in negotiation or the like executed with the STA 102. If traffic with a delay request is included in the communication with the STA 102 (YES in S901), the AP 101 may notify the STA 102 that NPCH access is executable on the condition that the traffic corresponds to the traffic (S902). On the other hand, if traffic with a delay request is not included (NO in S901), the AP 101 may notify the STA 102 that NPCH access is not executable (S608).

[0044] As an example, FIG. 10 shows an example of an information element for notifying a condition to be satisfied when executing an NPCH access generated in the AP 101. This information element is another example of an element that may be called an NPCH access element. The NPCH access element in FIG. 10 includes an Element ID field 401, a Length field 402, an Extended Element ID field 403, and an NPCH Access Control field 404. The NPCH access element may also include an NPCH Access Parameter Update field 405 as an option. In FIG. 10, the same reference numbers are used for fields that have the same roles as those in FIG. 4, and descriptions thereof will be omitted. That is, the difference between the information element in FIG. 10 and the information element in FIG. 4 is that an NPCH Access Operation field 1001 is arranged instead of the NPCH Access Mode field 406. The NPCH Access Operation field 1001 indicates a condition to be satisfied when executing an NPCH access generated in the AP 101. For example, FIG. 10 shows an example in which the condition to be satisfied when executing an NPCH access is that the traffic communicated corresponds to a predetermined type. Here, each bit constituting the NPCH Access Operation field 1001 may correspond to a TID (Traffic Identifier) ​​that identifies the type of traffic to be communicated. For example, the TID may be associated with each type of traffic (voice traffic, image traffic, best effort traffic, etc.) communicated between the AP 101 and the STA 102. The TID may be associated with an Access Category or an individual application (print job, photo share, etc.). The AP 101 may also classify the type of traffic to be communicated using a method other than these. In this case, the NPCH Access Operation field 1001 may be configured according to the classification method used by the AP 101.The AP101 of this embodiment determines whether or not NPCH access can be performed for each TID, and sets a bit corresponding to each TID. For example, the AP101 sets a bit corresponding to a TID for which NPCH access is permitted to be performed to 1, and sets a bit corresponding to a TID for which NPCH access is prohibited to be performed to 0. The AP101 may control such that traffic with a delay requirement set, such as audio traffic or video traffic, is transmitted early even when the PCH cannot be used, by permitting NPCH access to such traffic. The AP101 may also control such that NPCH access is permitted to traffic that affects the user experience, such as print jobs or photo sharing.

[0045] FIG. 11 shows an example of a flow when the STA 102 transmits data in this processing example. In FIG. 11, the same reference numbers are given to operations common to FIG. 7, and the description is omitted. When the STA 102 detects that data is stored in the own device, the STA 102 executes carrier sense in the PCH and judges the detection status of the signal in the PCH (S701 to S703). When the PCH is in a busy state, the STA 102 judges whether the data to be transmitted satisfies the execution condition of the NPCH access (S1101). For example, the STA 102 acquires the condition to be satisfied when performing the NPCH access by receiving the NPCH Access Operation field 1001 included in the Beacon frame received from the AP 101. Also, for example, the STA 102 judges whether the TID of the data stored in the own device is a TID for which the NPCH access is permitted, thereby judging whether the condition to be satisfied when performing the NPCH access is satisfied. When the STA 102 determines that the TID of the data stored in the own device is a TID for which NPCH access is permitted (YES in S1101), the STA 102 can transmit the data using NPCH access (S707 to S709). On the other hand, when the STA 102 determines that the conditions for executing NPCH access are not satisfied (NO in S1101), the STA 102 does not execute NPCH access (S706).

[0046] The AP 101 may use a condition other than the communication traffic having a predetermined delay requirement as a condition to be satisfied when performing NPCH access. As an example, the AP 101 may set that the communication quality of the channel used for NPCH access is equal to or higher than a predetermined threshold as a condition to be satisfied when performing NPCH access. For example, the AP 101 may set the RSSI of the signal received from the AP 101 in the STA 102, the SINR in the STA 102, a packet error rate, a packet retransmission rate, a channel usage rate, and the like as parameters for determining the communication quality of the channel. For example, when the RSSI or SINR is low or when the packet error rate or the packet retransmission rate is high, there is a high possibility that communication will fail even if NPCH access is performed. By preferentially permitting NPCH access to STAs that are likely to succeed in communication, it becomes possible to effectively use frequency resources. The AP 101 may store and transmit thresholds such as the RSSI, SINR, packet error rate, packet retransmission rate, and channel usage rate in the NPCH Access Operation field 1001. By receiving the NPCH Access Operation field 1001, the STA102 obtains various thresholds as conditions to be satisfied when performing NPCH access. The STA102 compares the SINR calculated using the RSSI of the signal received from the AP101 and the RSSI of the interference signal with these thresholds to determine whether or not the conditions to be satisfied when performing NPCH access are satisfied. The STA102 can also compare the error rate and retransmission rate measured for a signal transmitted by the own device using the PCH or NPCH with these thresholds to determine whether or not the conditions to be satisfied when performing NPCH access are satisfied. The STA102 can measure the channel usage rate in the SPCH and compare it with the threshold to determine whether or not the conditions to be satisfied when performing NPCH access are satisfied. Note that, since signals that can be received in the SPCH differ depending on the physical location of each communication device, the channel usage rates measured by each STA may differ from each other.The AP 101 provides a threshold value and each STA makes an individual decision, so that STAs that are more likely to succeed can be given priority in performing NPCH access.

[0047] The conditions that can be applied as the conditions to be satisfied when the AP 101 executes NPCH access are not limited to the above. For example, the AP 101 may use the traffic accumulation status in the STA 102 as a condition. As an example, the AP 101 may notify the STA 102 of a threshold value such as the amount of data accumulated in the transmission buffer or the number of packets as a condition to be satisfied when the AP 101 executes NPCH access. By controlling the STA that accumulates a lot of communication traffic to execute NPCH access preferentially, the traffic congestion in the STA may be eliminated. In this case, the AP 101 may store the threshold value such as the amount of data accumulated in the buffer or the number of packets in the NPCH Access Operation field 1001 and notify the STA 102.

[0048] In this manner, in this embodiment, the AP 101 generates conditions to be satisfied when performing NPCH access and notifies the STA 102. The STA 102 determines whether or not the STA 102 may perform NPCH access by determining whether or not the own device or the traffic of the own device satisfies the notified conditions. By making the STA that needs to transmit data early and the STA that is relatively likely to succeed in communication perform NPCH access, it becomes possible to use frequency resources effectively. The conditions to be satisfied when performing NPCH access may be a combination of the above conditions. In addition, conditions other than the above conditions may also be used. In this case, the NPCH Access Operation field 1001 may be provided with the same number of fields as the number of conditions. The NPCH Access Operation field 1001 may be transmitted using an Action frame. In this case, the NPCH Access Operation field 1001 is stored instead of the NPCH Access Mode field 406 in FIG. 5. When the conditions to be satisfied when performing NPCH access periodically using a Beacon frame are notified, the information is periodically transmitted even when there is no change in the conditions. By using the Action frame, it is possible to notify only when there is a change in the conditions, thereby making it possible to use frequency resources effectively. Also, the NPCH Access Mode field 406 and the NPCH Access Operation field 1001 may be included in one element or field. In this case, when the NPCH Access Mode field 406 is set to 1, the setting of the NPCH Access Operation field 1001 may be validated. The STA 102 only needs to analyze the contents of the NPCH Access Operation field 1001 when the NPCH Access Mode field 406 is set to 1, making it possible to reduce the processing load.

[0049] [Processing example 3] The IEEE802.11be standard defines a communication method (multi-link communication) that uses multiple links in parallel, called a Multi-Link Operation function. If the communication device 100 can execute multi-link communication in addition to NPCH access, the communication device 100 can use multi-link communication and NPCH access in parallel. In this processing example, a function is provided that determines whether to use NPCH access based on whether the AP 101 and the STA 102 can execute multi-link communication.

[0050] FIG. 12 shows an example of a flow for determining whether or not to use NPCH access in this processing example. This flow may be executed in AP101, for example. This flow may be executed by STA102, or may be executed while communicating between AP101 and STA102. In the following, this flow will be described as an example executed by AP101. First, AP101 determines whether or not STA102 has a function for executing NPCH access (S1201). For example, AP101 may check whether or not STA102 has a function for executing NPCH access by exchanging Capabilities elements, etc., in a procedure for establishing a link with STA102. If STA102 does not have a function for executing NPCH access (NO in S1201), AP101 decides not to use NPCH access (S1206). On the other hand, if the STA 102 has a function for performing NPCH access (YES in S1201), the AP 101 judges whether a multilink connection has been established with the STA 102 (S1202). For example, the AP 101 can judge whether a multilink connection exists by checking whether multiple links have already been established with the STA 102 or only one link has been established. If a multilink connection has not been established (NO in S1202), the AP 101 decides not to use NPCH access (S1206). On the other hand, if a multilink connection has been established (YES in S1202), the AP 101 judges whether communication can be performed in the STR method in the multilink connection established with the STA 102 (S1203). STR is an abbreviation for Simultaneous Transmit and Receive. The STR method is a communication method in which signals are transmitted and received independently simultaneously between multiple links that do not interfere with each other. That is, when the AP 101 can use the link using the NPCH access and the other links independently, the AP 101 can communicate information required for controlling the NPCH access using the other links. On the other hand, when the STR method communication is not possible on these links, there is a possibility that the communication on the other links and the NPCH access may be interfered with or restricted by each other.If the AP 101 cannot perform multi-link communication using the STR method (NO in S1203), the AP 101 decides not to use NPCH access (S1206). On the other hand, if the AP 101 can perform multi-link communication using the STR method (YES in S1203), the AP 101 judges whether or not a link can be added (S1204). For example, if a link can be added, adding a new link makes it possible to perform necessary communication without using NPCH access. The AP 101 can judge whether or not a new link can be added by, for example, checking whether or not the AP 101 has a wireless processing function that can be used to establish a new link in addition to the wireless processing function that is used for the multi-link communication already established with the STA 102. If the AP 101 cannot perform a link (YES in S1204), the AP 101 decides to use NPCH access (S1207). On the other hand, if the AP 101 can perform a link (YES in S1204), the AP 101 judges whether or not the bandwidth of the link that can be added is narrower than the bandwidth of the existing link (S1205). When the bandwidth of the link that can be added is narrower than that of the existing link, it may be possible to perform faster communication by using NPCH access. When the bandwidth of the link that can be added is narrower than that of the existing link (YES in S1205), AP101 decides to use NPCH access (S1207). On the other hand, when the bandwidth of the link that can be added is wider than that of the existing link (NO in S1205), AP101 decides to use NPCH access (S1206).

[0051] In this manner, in this processing example, when multilink communication and NPCH access can be used in parallel between communication devices, whether or not to use NPCH access is determined based on interference between multilink communication and NPCH access and the bandwidth that each can use. This makes it possible to improve frequency utilization efficiency while avoiding interference and restrictions between multilink communication and NPCH access. The method of determining whether or not to use NPCH access when multilink communication and NPCH access can be used in parallel between communication devices is not limited to this. Depending on the communication quality and traffic conditions in each link of the multilink, whether or not to execute each of the multilink communication and NPCH access may be dynamically determined. Also, whether or not to execute NPCH access may be switched in each link of the multilink.

[0052] (Device configuration) 13 shows an example of a hardware configuration of the communication device 100 (AP 101 and STA 102) of this embodiment. As an example of the hardware configuration, the communication device 100 has, for example, a storage unit 1301, a control unit 1302, a function unit 1303, an input unit 1304, an output unit 1305, a communication unit 1306, and an antenna 1307. The communication device 100 may have multiple antennas.

[0053] The storage unit 1301 is configured with one or more memories including a ROM, a 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 601 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 a ROM and a RAM.

[0054] The control unit 1302 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 1301. The control unit 1302 may control the entire communication device 100 in cooperation with the control program stored in the storage unit 1301 and an OS (Operating System). The CPU and MPU are abbreviations for Central Processing Unit and Micro Processing Unit, respectively. When the control unit 1302 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.

[0055] Furthermore, the control unit 1302 controls the functional unit 1303 to execute predetermined processes such as communication, image capture, printing, and projection. The functional unit 1303 is hardware for the communication device 100 to execute the above-mentioned predetermined processes. For example, if the device is a camera, the functional unit 1303 is an image capture unit and performs image capture processing. Also, for example, if the device is a printer, the functional unit 1303 is a print unit and performs print processing. Also, for example, if the device is a projector, the functional unit 1303 is a projection unit and performs projection processing.

[0056] The input unit 1304 receives various operations from the user. The output unit 1305 performs various outputs to the user via a monitor screen or a speaker. Here, the output by the output unit 1305 may be a display on a monitor screen, a voice output by a speaker, a vibration output, or the like. Note that the input unit 1304 and the output unit 1305 may both be realized by one module, such as a touch panel. Also, the input unit 1304 and the output unit 1305 may be devices integrated with the communication device 100, or may be separate devices.

[0057] The communication unit 1306 controls wireless communication conforming to the IEEE802.11bn standard. The communication unit 1306 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 1306 controls the antenna 1307 to transmit and receive signals for wireless communication generated by the control unit 1302. The communication unit 1306 is a so-called wireless chip, and may itself include one or more processors and memories. Note that, when 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 1306 may control communication conforming to these communication standards. Also, when the communication device 100 can perform wireless communication conforming to a plurality of 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 a counterpart communication device via the communication unit 1306. The antenna 1307 may be configured separately from the communication unit 1306, or may be configured as one module together with the communication unit 1306. 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 1306 as necessary for that purpose.

[0058] Antenna 1307 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. 7, communication device 100 has two antennas 1307, 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 1306 for each antenna.

[0059] (Functional configuration) 14 shows an example of the functional configuration of the communication device 100. The functional configuration in this embodiment is an example of a functional configuration realized by, for example, one or more processors executing a program stored in one or more memories. The communication device 100 includes a frame control unit 1401, a NAV detection unit 1402, a wireless communication control unit 1403, an NPCH access control unit 1404, an NPCH access condition determination unit 1405, and a frame analysis unit 1406.

[0060] The frame control unit 1401 generates a signal (frame) when communicating with a communication device of a counterpart. For example, the frame control unit 1401 generates a frame for notifying the STA 102 of information (first information) that can be used by the AP 101 to determine whether or not NPCH access can be performed. For example, the frame control unit 1401 generates a Beacon frame including an NPCH Access element for notifying whether or not NPCH access can be performed and conditions that should be satisfied when performing NPCH access. The frame control unit 1401 may generate an Action frame including an NPCH Operating Mode Notification frame Action field. In addition, the frame control unit 1401 generates a frame for requesting information (second information) that can be used by the AP 101 to determine whether or not NPCH access can be performed and generate conditions that should be satisfied when performing NPCH access. For example, the frame control unit 1401 may generate an Action frame including a Measurement Request element. On the other hand, the frame control unit 1401 generates a frame for providing the AP 101 with information that the STA 102 can use to determine whether or not the AP 101 can perform NPCH access and to generate conditions that should be satisfied when performing NPCH access. For example, the frame control unit 1401 can generate an Action frame that includes a Measurement Report element.

[0061] The NAV detection unit 1402 sets the NAV of the PCH or SPCH based on the value of Duration extracted by the frame analysis unit 1406. The wireless communication control unit 1403 performs a transmission process for each frame generated by the frame control unit 1401. The wireless communication control unit 1403 also notifies the frame analysis unit 1406 of a frame received via the antenna 1307. For example, the wireless communication control unit 1403 may transmit or receive a data frame using either the first communication method or the second communication method. As an example, the wireless communication control unit 1403 performs 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 1402, the wireless communication control unit 1403 may perform carrier sense of the SPCH based on the determination of whether or not NPCH access can be performed in the NPCH access condition determination unit 1405. For example, when the radio communication control unit 1403 does not detect a signal in the SPCH and the NAV detection unit 1402 does not set the NAV in the SPCH, the radio communication control unit 1403 transmits a data frame using one or more NPCHs including the SPCH. The SPCH control unit 1404 executes setting and control for performing NPCH access. For example, the SPCH control unit 1404 executes setting such as the channel number of the SPCH and the priority order for performing carrier sense based on the parameters included in the NPCH Access Parameter Update field 405. The SPCH control unit 1404 may execute setting and control using setting information required for performing NPCH access, which is exchanged when a link is established between the AP 101 and the STA 102. The NPCH access condition determination unit 1405 determines whether or not NPCH access may be performed. For example, the NPCH access condition determination unit 1405 in the AP 101 executes determination of whether or not NPCH access is executable and generates conditions to be satisfied when performing NPCH access based on the communication quality of the NPCH and the traffic accumulation status in the STA 102. Furthermore, the NPCH access condition decision section 1405 requests the STA 102 for second information required for deciding whether or not NPCH access can be performed and for generating conditions that should be satisfied when performing NPCH access.The NPCH access condition determination unit 1405 in the STA102 determines whether or not NPCH access may be performed based on the first information extracted from the NPCH Access element, etc. The NPCH access condition determination unit 1405 also provides the AP101 with second information required for the AP101 to determine whether or not NPCH access may be performed and to generate conditions to be satisfied when performing NPCH access. The frame analysis unit 1406 can acquire information required for communication by analyzing a frame received from a communication device of the other party. For example, the frame analysis unit 1406 in the STA102 acquires information (first information) that can be used to determine whether or not NPCH access may be performed from a Beacon frame or an Action frame. The frame analysis unit 1406 in the AP101 also acquires information (second information) that can be used to determine whether or not NPCH access may be performed from an Action frame including a Measurement Report element. The second information can also be used to generate conditions to be satisfied when performing NPCH access. The frame analysis unit 1406 can obtain the value of Duration by analyzing the received frame and notify the NAV detection unit 1402 of the value.

[0062] As described above, according to the present embodiment, even if the PCH cannot be used, communication using the NPCH is executed based on carrier sense in the SPCH. This makes it possible to efficiently use the frequency of the link, and increases the communication capacity provided by the wireless communication system. In addition, according to the present embodiment, whether or not to execute the NPCH access is determined based on the communication quality in the PCH and NPCH and the traffic accumulation status in the communication device. This makes it possible to perform appropriate communication according to the situation, such as executing the NPCH access when the success rate of the NPCH access is high or when communication needs to be performed early, and performing a power saving operation in other cases. Note that, although the present embodiment illustrates communication between the AP101 and the STA102, the present technology can also be applied between a plurality of STAs. In addition, in the present embodiment, a case where a communication method that does not use the PCH is called NPCH access is illustrated, but this 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 the NPCH is possible is referred to as SPCH for convenience, but this is not limited thereto. Among multiple secondary channels, the channel with the highest priority for determining whether transmission is possible may be called PSCH (Primary Secondary Channel). Regardless of which term is used, it means that the channel should be used to determine whether transmission using the NPCH is possible. The names of the information elements and various fields in this embodiment may be called by other names. In this embodiment, an example has been shown in which the feasibility of NPCH access is determined depending on the communication quality of the channel and the traffic accumulation status in the communication device, but the feasibility of NPCH access may be determined based on information other than these.

[0063] 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.

[0064] (Summary of the embodiment) At least some of the above-described embodiments can be summarized as follows. (Item 1) A communication device capable of communicating with another 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, in one communication link including the first channel, the communication device comprising: a notification means for notifying the other communication device having a function capable of performing communication using the second communication method of first information usable by the other communication device to determine whether or not communication using the second communication method may be performed; and a communication means for communicating data between the communication device and the other communication device connected thereto using one or more channels including either the first channel or the second channel based on the first information. A communication device comprising: (Item 2) The communication device according to item 1, wherein the first information includes information indicating whether the other communication device is permitted or prohibited from communicating using the second communication method. (Item 3) 2. The communication device according to item 1, wherein the first information includes information indicating a condition that must be satisfied when the other communication device executes communication in the second communication method. (Item 4) The notification means periodically notifies the first information by using a Beacon frame defined in the IEEE 802.11 series standard. 4. The communication device according to any one of items 1 to 3, (Item 5) The notification means notifies the first information by using an Action frame defined in the IEEE 802.11 series standard. 5. The communication device according to any one of items 1 to 4, (Item 6) The method further includes acquiring means for acquiring second information usable for generating the first information from the other communication device. 6. The communication device according to any one of items 1 to 5, (Item 7) The second information includes information capable of identifying a communication quality in the second channel. 7. The communication device according to item 6, (Item 8) The second information includes information capable of identifying an accumulation status of communication traffic in the other communication device. 7. The communication device according to item 6, (Item 9) A communication device capable of communicating with another 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, in one communication link including the first channel, the communication device comprising: an acquisition means for acquiring first information from the other communication device, the first information being usable for determining whether or not communication using the second communication method may be performed; a determination means for determining whether or not communication using the second communication method may be performed using the first information; and a communication means for communicating data with the other communication device using one or more channels including either the first channel or the second channel based on a result of the determination. A communication device comprising: (Item 10) 10. The communication device according to item 9, wherein the first information includes information indicating whether the communication device is permitted or prohibited from performing communication in a second communication method. (Item 11) 10. The communication device according to item 9, wherein the first information includes a condition that must be satisfied when the communication device executes communication in a first communication method. (Item 12) The acquiring means periodically acquires the first information from a Beacon frame defined in the IEEE 802.11 series standard. 12. The communication device according to any one of items 9 to 11, (Item 13) The acquiring means acquires the first information from an Action frame defined in the IEEE 802.11 series of standards. 12. The communication device according to any one of items 9 to 11, (Item 14) The communication device further includes a providing unit for providing second information usable by the other communication device to generate the first information. 13. The communication device according to any one of items 8 to 12, (Item 15) The second information includes information capable of identifying a communication quality in the second channel. 15. The communication device according to item 14, (Item 16) The second information includes information capable of identifying an accumulation status of communication traffic in the communication device. 15. The communication device according to item 14, (Item 17) A control method executed by a communication device capable of communicating with another 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 notification step of notifying the other communication device having a function capable of performing communication using the second communication method of first information usable by the other communication device to determine whether or not communication using the second communication method may be performed; and a communication step of communicating data between the communication device and the other communication device connected thereto using one or more channels including either the first channel or the second channel based on the first information. A control method comprising: (Item 18) A method executed by a communication device capable of communicating with another 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, the method comprising: an acquisition step of acquiring first information from the other communication device, the first information being usable for determining whether or not communication using the second communication method may be performed; a determination step of determining whether or not communication using the second communication method may be performed by using the first information; and a communication step of communicating data with the other communication device using one or more channels including either the first channel or the second channel based on a result of the determination. A control method comprising: (Item 19) A computer is provided in a communication device that can communicate with another communication device by a first communication method using one or more channels including 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 using one or more of the second channels when the first channel is unavailable, in one communication link composed of the first channel used to acquire a transmission right and the one or more second channels different from the first channel, notifying the other communication device having a function capable of performing communication using the second communication method of first information usable by the other communication device to determine whether or not communication using the second communication method may be performed; Based on the first information, data is communicated between the communication device and the other communication device connected thereto using one or more channels including either the first channel or the second channel. Program for. (Item 20) A computer is provided in a communication device that can communicate with another communication device by a first communication method using one or more channels including 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 using one or more of the second channels when the first channel is unavailable, in one communication link composed of the first channel used to acquire a transmission right and the one or more second channels different from the first channel, acquiring, from the other communication device, first information that can be used to determine whether or not communication using the second communication method may be performed; determining whether or not to execute communication using the second communication method by using the first information; Based on a result of the determination, data is communicated between the other communication device and the first communication device using one or more channels including either the first channel or the second channel. Program for.

[0065] 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]

[0066] 101: AP, 102: STA, 103: Network

Claims

1. A communication device capable of communicating with another 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, in one communication link including the first channel, the communication device comprising: a notification means for notifying the other communication device having a function capable of performing communication using the second communication method of first information usable by the other communication device to determine whether or not communication using the second communication method may be performed; and a communication means for communicating data between the communication device and the other communication device connected thereto, using one or more channels including either the first channel or the second channel, based on the first information. A communication device comprising:

2. The communication device according to claim 1 , wherein the first information includes information indicating whether the other communication device is permitted or prohibited from performing communication in the second communication method.

3. The communication device according to claim 1 , wherein the first information includes information indicating a condition that must be satisfied when the other communication device executes communication in the second communication method.

4. The notification means periodically notifies the first information by using a Beacon frame defined in the IEEE 802.11 series standard.

2. The communication device according to claim 1 .

5. The notification means notifies the first information by using an Action frame defined in the IEEE 802.11 series standard.

2. The communication device according to claim 1 .

6. The communication device further includes an acquisition unit for acquiring second information usable for generating the first information from the other communication device.

2. The communication device according to claim 1 .

7. The second information includes information capable of identifying a communication quality in the second channel.

7. The communication device according to claim 6.

8. The second information includes information capable of identifying an accumulation status of communication traffic in the other communication device.

7. The communication device according to claim 6.

9. A communication device capable of communicating with another 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, in one communication link including the first channel, the communication device comprising: an acquisition means for acquiring, from the other communication device, first information usable for determining whether or not communication using the second communication method may be performed; a determination means for determining whether or not communication using the second communication method may be performed using the first information; and a communication means for communicating data with the other communication device using one or more channels including either the first channel or the second channel based on a result of the determination. A communication device comprising:

10. The communication device according to claim 9 , wherein the first information includes information indicating whether the communication device is permitted or prohibited from performing communication in a second communication method.

11. The communication device according to claim 9 , wherein the first information includes a condition that must be satisfied when the communication device executes communication in a first communication method.

12. The acquiring means periodically acquires the first information from a Beacon frame defined in the IEEE 802.11 series standard.

10. The communication device according to claim 9 .

13. The acquiring means acquires the first information from an Action frame defined in the IEEE 802.11 series standard.

10. The communication device according to claim 9 .

14. The communication device further includes a providing unit for providing second information usable by the other communication device to generate the first information.

9. The communication device according to claim 8.

15. The second information includes information capable of identifying a communication quality in the second channel.

15. The communication device according to claim 14.

16. The second information includes information capable of identifying an accumulation status of communication traffic in the communication device.

15. The communication device according to claim 14.

17. A control method executed by a communication device capable of communicating with another 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, the method comprising: a notification step of notifying the other communication device having a function capable of performing communication using the second communication method of first information usable by the other communication device to determine whether or not communication using the second communication method may be performed; and a communication step of communicating data between the communication device and the other communication device connected thereto using one or more channels including either the first channel or the second channel based on the first information. A control method comprising:

18. A method executed by a communication device capable of communicating with another 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, the method comprising: an acquisition step of acquiring, from the other communication device, first information usable for determining whether or not communication using the second communication method may be performed; a determination step of determining whether or not communication using the second communication method may be performed by using the first information; and a communication step of communicating data with the other communication device using one or more channels including either the first channel or the second channel based on a result of the determination. A control method comprising:

19. A computer is provided in a communication device that can communicate with another communication device by a first communication method using one or more channels including 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 using one or more of the second channels when the first channel is unavailable, in one communication link including the first channel, notifying the other communication device having a function capable of performing communication using the second communication method of first information usable by the other communication device to determine whether or not communication using the second communication method may be performed; Based on the first information, data is communicated between the communication device and the other communication device connected thereto using one or more channels including either the first channel or the second channel. Program for.

20. A computer is provided in a communication device that can communicate with another communication device by a first communication method using one or more channels including 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 using one or more of the second channels when the first channel is unavailable, in one communication link including the first channel, acquiring, from the other communication device, first information that can be used to determine whether or not communication using the second communication method may be performed; determining whether or not communication using the second communication method may be performed using the first information; Based on a result of the determination, data is communicated between the other communication device and the first communication device using one or more channels including either the first channel or the second channel. Program for.

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