COMMUNICATION EQUIPMENT AND CONTROL METHODS

Abstract

The invention relates to a communication device capable of performing communication by means of a first channel access method which uses at least one primary channel in a link and a second channel access method which, in the case where the primary channel is busy, uses at least one non-primary channel other than the primary channel from among several channels included in the link instead of using the primary channel, notifying another communication device, which has the function of performing communication by means of the second channel access method, of the first information which can be used by the other communication device to determine whether communication by means of the second channel access method is permitted; and communicating with the other communication device which receives the first information.

Description

Communication device, control method, and program

[0001] The present disclosure relates to a data communication technique in a communication device capable of communication using a communication link configured by a plurality of channels.

[0002] In recent years, with the increase in the amount of data being communicated, development of communication technologies such as wireless LANs (Local Area Networks) has been progressing. The Institute of Electrical and Electronic Engineers (IEEE) 802.11 standard series is known as a major communication standard for wireless LANs. The IEEE 802.11 standard series includes IEEE 802.11a / b / g / n / ac / ax / be standards, etc. In order to further improve communication reliability, development of the IEEE 802.11bn standard is underway as a successor to the IEEE 802.11be standard. In the IEEE 802.11 Working Group (WG), which formulates the IEEE 802.11bn standard, the UHR SG will determine the goals and scope of the standard, and the TGbn will specify the detailed technical content to be included in the standard. UHR SG is an abbreviation for Ultra High Reliability Study Group. TGbn is an abbreviation for Task Group bn.

[0003] As one of the candidate technologies to be included in the IEEE 802.11bn standard, a technology for efficiently utilizing frequency resources in a communication method using a communication link configured with multiple channels is being considered. For example, Patent Document 1 describes a technology for performing communication using another channel when a primary channel used to acquire a transmission right cannot be used.

[0004] U.S. Pat. No. 1,169,6353

[0005] The present disclosure discloses a technique for more efficiently utilizing frequency resources in a communication system that uses a communication link consisting of multiple channels.

[0006] A communication device according to one aspect of the present disclosure is capable of communicating using a first channel access method that uses one or more channels including at least a specified primary channel in a link, and a second channel access method that does not use the primary channel when the primary channel is busy and uses at least one non-primary channel different from the primary channel among multiple channels included in the link, and has a notification means for notifying other communication devices that have the function of performing communication using the second channel access method of first information that can be used by the other communication devices to determine whether or not it is permissible to perform communication using the second channel access method, and a communication means for communicating with the other communication devices that have received the first information.

[0007] According to the present disclosure, frequency resources can be utilized more efficiently in a communication system that uses a communication link consisting of multiple channels.

[0008] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals.

[0009] The accompanying drawings are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention, and are used to explain the principles of the present invention together with the description thereof.

[0023] Figure 1 is a diagram showing an example of the configuration of a wireless communication system.

[0024] Figure 2 is a schematic diagram showing an example of a time chart when a communication device transmits data.

[0025] Figure 3 is a schematic diagram showing an example of a time chart when a communication device transmits data.

[0026] Figure 4 is a diagram showing an example of a flow when an AP notifies a STA of whether NPCH access can be performed.

[0027] Figure 5 is a diagram showing an example of an NPCH Access element.

[0028] Figure 6 is a diagram showing an example of an NPCH Operating Mode Notification frame Action field.

[0029] Figure 7 is a diagram showing an example of a flow when determining whether NPCH access can be performed.

[0030] Figure 8 is a diagram showing an example of a sequence executed between communication devices.

[0031] Figure 9 is a diagram showing an example of a flow when determining conditions for whether NPCH access can be performed.

[0032] Figure 10 is a diagram showing an example of a NPCH Access element.

[0033] Figure 11 is an example of a flow chart showing a flow of channel access by a communication device.

[0034] Figure 12 is a diagram showing an example of a flow when determining whether NPCH access can be performed.

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] (System Configuration) FIG. 1 shows an example 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 each communication devices capable of performing wireless communication in accordance with the IEEE 802.11 standard series. In this embodiment, the AP 101 and the STA 102 may be collectively referred to as a communication device 100. IEEE stands for Institute of Electrical and Electronics Engineers. FIG. 1 shows a configuration in which the STA 102 participates in a network 103 established by the AP 101. The network 103 may also be referred to as a Basic Service Set (BSS). While FIG. 1 shows a configuration in which one AP 101 and one STA 102 exist, multiple APs and multiple STAs may exist. Furthermore, at that time, multiple STAs may be connected to one AP, or one STA may be connected to multiple APs. In FIG. 1 , a network 113 configured by AP 111 and STA 112 exists near a network 103 configured by AP 101 and STA 102. Like AP 101 and STA 102, AP 111 and STA 112 are communication devices capable of performing wireless communication compliant with the IEEE 802.11 standard series. For AP 101 and STA 102, network 103 is a BSS to which they connect, and may be referred to as 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 referred to as an overlapping BSS (OBSS).

[0012] In this embodiment, the AP 101 and the STA 102 are configured to be able to execute a communication method conforming to the IEEE 802.11bn standard. The IEEE 802.11bn standard is a successor to the IEEE 802.11be standard, which targets a maximum transmission speed of 46.08 Gbps (Giga bit per second). The main features of the IEEE 802.11bn standard are that it has functions that realize highly reliable communication, low latency communication, and improved throughput when communication traffic is congested. The wireless frame used in the communication method conforming to this standard may be called a UHR (Ultra High Reliability) PPDU. PPDU stands for PLCP Protocol Data Unit, and PLCP stands for Physical Layer Convergence Protocol. It should be noted that names such as UHR and IEEE 802.11bn may be changed to other names when the standards are fully established. It should be noted that this specification and the claims attached hereto are applicable to communication devices using all successor standards to IEEE 802.11be. The communication device 100 may also be compatible with at least one legacy standard that predates the IEEE 802.11bn standard. Examples of legacy standards include the IEEE 802.11a / b / g / n / ac / ax / be standards. The communication device 100 may also 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 may be, for example, a wireless LAN router or a personal computer (PC), but is not limited to these. The AP 101 may also be an information processing device, such as a wireless chip, capable of performing wireless communication compatible with the IEEE 802.11bn standard, etc.The STA 102 may be, for example, but is not limited to, a camera, a tablet, a smartphone, a PC, a mobile phone, a video camera, a headset, etc. The STA 102 may be an information processing device such as a wireless chip capable of performing wireless communication compatible with the IEEE 802.11bn standard or the like.

[0013] The communication device 100 may communicate using radio signals in frequency bands such as the 2.4 GHz band, the 3.6 GHz band, the 5 GHz band, the 6 GHz band, and the 45 GHz band and 60 GHz band, which are called millimeter waves. The frequency bands used by the communication device 100 are not limited to these and may be, for example, the Sub 1 GHz band. The communication device 100 may also communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by the communication device 100 are not limited to these and may be, for example, 240 MHz, 4 MHz, etc. The IEEE 802.11 standard series specifies a frequency channel using a 20 MHz bandwidth as a basic channel in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands. This standard also defines multiple available channels in each of the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. This standard allows the communication device 100 to use a channel in combination with an adjacent channel. This use of a channel in combination with an adjacent channel may be referred to as channel bonding. A bundle of channels formed by one or two or more adjacent channels may be referred to as a communication link. For example, a link formed by two channels with a bandwidth of 20 MHz may use a bandwidth of 40 MHz. The IEEE 802.11be standard is expected to specify 320 MHz as the maximum available bandwidth for a single link. Signals transmitted in this bandwidth may be continuous or discontinuous on the frequency axis. The AP 101 and the STA 102 may be an AP MLD (Multi-Link Device) and a STA MLD, respectively, that support Multi-Link, which establishes multiple links simultaneously for communication.

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

[0015] For example, when communicating using a link with a bandwidth of 160 MHz, the communication device 100 may determine whether or not to transmit using only the 20 MHz Primary Channel (PCH) included in that link. For example, the IEEE 802.11 series of standards describes that the communication device 100 can start transmission if it determines that transmission is possible as a result of performing carrier sensing on the PCH for a predetermined period of time. The predetermined period is determined by an Interframe Space (IFS) defined for each access category that classifies the type of communication traffic, and a random number (backoff counter) randomly determined from a predetermined range. In other words, if the communication device 100 determines that the PCH is idle for this predetermined period of time, it acquires the right to transmit using that link. At this time, if a channel other than the PCH was idle during the PIFS period immediately before the start of transmission, the communication device 100 may perform transmission using channel bonding using the idle channel and the PCH. PIFS is an abbreviation for Priority Interframe Space. Furthermore, when the communication device 100 determines that transmission is not possible as a result of carrier sensing on the PCH, it may postpone transmission even if other channels included in the same link are idle. Each channel other than the PCH that constitutes a single link may be called a secondary channel (SCH). A secondary channel may also be called a non-primary channel (NPCH).

[0016] When a communication device 100 receives a signal on a certain channel, if a signal is transmitted on another channel (e.g., an adjacent channel) located at a frequency close to the received channel, the received signal may not be properly received. For example, assume that the communication device 100 is capable of simultaneously performing transmission and reception processes using different channels. If the communication device 100 receives a signal on a certain channel and then transmits on an adjacent channel, the power of the transmitted signal will leak into the channel of the received signal, causing interference with the received signal. Generally, the power of such transmitted signal leakage is much greater than the received power of the received signal, so the received signal will not be properly received. To avoid this situation, the IEEE 802.11 standard series provides a mechanism to prevent other communication devices from transmitting signals to a communication device using a channel adjacent to the PCH while the communication device is transmitting a signal. That is, the PCH is provided as a channel commonly used between communication devices to determine whether or not to transmit, and it is specified that while one communication device is transmitting using the PCH, the other communication device will not transmit, even if the other channel is idle. As a result, while a communication device is transmitting a signal and a PCH is in use, other communication devices will not transmit signals using a channel adjacent to the PCH, preventing the communication device from receiving a signal on that adjacent channel, thereby eliminating the problem of interference caused by power leakage between channels.

[0017] However, not using other idle channels (NPCHs) based on the PCH being busy can hinder efficient use of frequency resources across the link. Figure 2A shows an example of a time chart when the STA 102 transmits data to the AP 101. In Figure 2A, the STA 102 performs carrier sensing on the PCH, confirms that the PCH is idle, and then transmits data using the PCH with a 20 MHz bandwidth. In this case, even if, for example, seven NPCHs other than the PCH are idle, other communication devices are not permitted to communicate using the NPCHs. Figure 2B also shows another example of a time chart when the STA 102 transmits data to the AP 101. In Figure 2B, while the STA 102 is performing carrier sensing on the PCH, the PCH is being used by another network (e.g., network 113 in Figure 1) located geographically near the STA 102. In this case, the PCH is determined to be busy by the carrier sense performed by STA 102, and therefore, even if the seven NPCHs other than the PCH are idle, STA 102 is not permitted to communicate with AP 101 using the NPCH. However, because AP 101 is not transmitting at this time, even if STA 102 transmits to AP 101 using the NPCH, AP 101 can properly receive the signal transmitted by STA 102. In this way, if the PCH with a bandwidth of, for example, 20 MHz is used by another network, the remaining 140 MHz of idle NPCHs are not utilized, resulting in inefficient use of frequency resources.

[0018] In consideration of these circumstances, this embodiment provides a function for performing communication between communication devices using NPCHs included in the same link as the PCH, without using the PCH, when the PCH is being used by another communication device. As an example, when the PCH is busy, the communication device 100 sets a Secondary Primary Channel (SPCH) to be used to acquire a transmission right for transmission using the NPCH. The SPCH is one or more channels among the NPCHs included in the same link as the PCH. When the communication device 100 determines that the PCH is being used by another communication device, it then determines whether transmission is possible on the SPCH. When the communication device 100 determines that transmission is possible on the SPCH, it performs transmission using one or more NPCHs including the SPCH. In this embodiment, a communication method for performing transmission using one or more channels including the SPCH without using the PCH is called NPCH access (Non-Primary Channel Access, NPCA). This communication method may be called by other names, for example, SCA (Secondary Channel Access).

[0019] In this embodiment, the AP 101 and the STA 102 communicate using a first communication method using one or more channels including a PCH and a second communication method (NPCH access) using one or more NPCHs not including a PCH. For example, the AP 101 and the STA 102 have the capability to execute both the first and second communication methods, and may communicate using the first communication method when a PCH is available, and may communicate using the second communication method when a PCH is unavailable. The PCH and the NPCH may be referred to as the first channel and the second channel, respectively. Here, even when a PCH is unavailable, it may be more efficient not to perform NPCH access and postpone transmission until a PCH becomes available. For example, when congestion occurs on the NPCH, communication via NPCH access is likely to be unavailable. In such a situation, it may be more efficient to perform power-saving operation without attempting NPCH access. In this embodiment, a technique is provided that enables the AP 101 and the STA 102 to dynamically control whether or not to actually perform communication via NPCH access in a situation where such communication is possible.

[0020] (Examples of Processing Executed by the AP 101 and the STA 102) Hereinafter, several examples of the flow of processing executed by the AP 101 and the STA 102 in this embodiment will be described.

[0021] [Processing Example 1] (Notification of Information Regarding NPCH Access) In this embodiment, the AP 101 determines whether or not to perform NPCH access and, based on the determination result, notifies the STA 102 of information indicating whether or not NPCH access is possible. The AP 101 and the STA 102 then determine the communication method to use for communication based on the determination result. For example, the AP 101 may transmit a notification that NPCH access is possible if performing NPCH access would improve overall system efficiency, and a notification that NPCH access is not permitted otherwise. This prevents the AP 101 and the STA 102 from attempting NPCH access when such access is inappropriate. The AP 101 may employ various criteria to improve overall system efficiency. For example, if the PCH or NPCH is congested, there is a possibility that an attempt to access the NPCH will fail to obtain a transmission right. In this case, it may be more energy efficient to wait while performing power-saving operation until the PCH becomes idle rather than attempting NPCH access. On the other hand, when transmitting traffic with a delay requirement, proactively attempting NPCH access can improve delay characteristics. Furthermore, by not allowing NPCH access for traffic without a delay requirement, the possibility of collision with traffic with a delay requirement can be reduced, thereby improving the probability of successful transmission of traffic with a delay requirement. Furthermore, to efficiently utilize NPCH access, only communication terminals with high communication quality may be permitted to access NPCH, thereby increasing the probability of successful NPCH access for the entire system. Furthermore, efficiency can be improved by combining this with other functions such as multi-link communication. The criteria by which the AP 101 determines whether or not to perform 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 perform NPCH access. In the following description, an example is shown in which the AP 101 notifies the STA 102 whether or not to perform NPCH access. However, the STA 102 may also notify the AP 101.Furthermore, unless inconsistent, all of the processes described below as being performed by the AP 101 may be performed by the STA 102.

[0022] 3 shows a flow when the AP 101 notifies the STA 102 whether or not to execute NPCH access. First, the AP 101 determines whether or not to permit execution of NPCH access (S301). The operation of the AP 101 in determining whether or not to permit execution of NPCH access will be described later. If 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 below) (S302). In this case, the AP 101 and the STA 102 execute communication using either the PCH or the NPCH access based on the results of carrier sensing on the PCH. For example, if the PCH is idle (YES in S303), the AP 101 and the STA 102 execute communication using the PCH (S306). On the other hand, if the PCH is not idle (NO in S303), the AP 101 and the STA 102 execute communication using the NPCH access (S304).

[0023] 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 (S305). In this case, the AP 101 and the STA 102 perform communication using the PCH (S306).

[0024] 4 shows an example of an information element (information element) used by the AP 101 to notify the STA 102 whether or not NPCH access can be performed. This information element may be called an NPCH Access element. This information element may also be called by other names. The AP 101 notifies the STA 102 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 optionally include an NPCH Access Parameter Update field 405. 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.

[0025] 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 NPCH access is executable. For example, if the AP 101 permits execution of NPCH access, it stores 1 in this field. On the other hand, if the AP 101 prohibits execution of NPCH access, it stores 0 in this field. The STA 102 can determine whether execution of 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 NPCH access is executable is not limited to this method. For example, the availability of NPCH access may be indicated by a non-zero value in a field related to NPCH access, such as the NPCH Access Parameter Update field 405 described below. The NPCH Access Parameter Update Control field 407 indicates whether the NPCH Access Parameter Update field 405 is present. For example, if the NPCH Access element includes the NPCH Access Parameter Update field 405, a value of 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, a value of 0 is stored in this field.

[0026] 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 that can identify the NPCH (i.e., the SPCH) on which carrier sensing should be performed when the STA 102 performs NPCH access. For example, the Secondary Primary Channel Number field 408 stores the channel number of the SPCH. By acquiring the value of the Secondary Primary Channel Number field 408, the STA 102 can ascertain the channel on which carrier sense should be performed when the STA 102 performs NPCH access. The method for specifying the SPCH is not limited to the channel number of the SPCH, and may be, for example, information indicating the relative position of the SPCH on the frequency axis with respect to the PCH. Note that, if 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 of carrier sense execution assigned to each SPCH. By notifying the priority of carrier sense execution, it becomes possible to perform NPCH access while synchronizing between the AP 101 and the STA 102, even if multiple SPCHs are configured. Furthermore, the AP 101 may provide a field for storing information indicating the priority of each SPCH, and may determine the location of the SPCH information according to the priority. For example, the AP 101 may arrange information related to an SPCH with a higher priority closer to the beginning of the field.

[0027] The NPCH Access Transition Delay field 409 indicates the switching time required for the AP 101 to switch the channel on which carrier sensing is performed. For example, the NPCH Access Transition Delay field 409 is configured with 3 bits, and values ​​of 0, 1, 2, 3, 4, and 5 indicate switching times of 0, 16, 32, 64, 128, and 256 μsec, respectively. The STA 102 obtains the value of the NPCH Access Transition Delay field 409 included in the Beacon frame and can switch the channel on which carrier sensing is performed in accordance with the operation of the AP 101. For example, if the STA 102 detects that the PCH is busy, it can start carrier sensing on the SPCH after this switching time has elapsed. In this way, when the AP 101 indicates whether or not NPCH access can be performed, the AP 101 also notifies the STA 102 of information to be used 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 can be omitted. Furthermore, if any parameter does not need to be updated, the field corresponding to that parameter can be omitted.

[0028] 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 made by the AP 101 as to whether or not NPCH access can be performed in a timely manner. Furthermore, if the determination as to 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 transmitted periodically. By using an Action frame instead of a Beacon frame, it is possible to transmit the Action frame only when a determination is made or when the determination result as to whether or not NPCH access can be performed differs from the previous determination result. Furthermore, by using an Action frame, it is possible to individually adjust the parameters to be used for NPCH access for each STA.

[0029] 5 shows an example of an Action Field (field) for notifying whether NPCH access is possible. This field may be called an NPCH Operating Mode Notification frame Action field. This field may also 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. In addition, the NPCH Operating Mode Notification frame Action field may include an NPCH Access Parameter Update field 405. 5, fields having the same functions as those in FIG. 4 are assigned the same reference numbers, 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 Protected UHR category. 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 the response frame and transmits it.

[0030] Note that STA 102 may transmit a request for permission to execute NPCH access to 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 AP 101 receives a Non-primary Channel Access Request frame, it may determine whether or not to permit STA 102, the sender, to execute NPCH access, and notify the AP of the determination result. The Action frame for notifying the determination result may be called a Non-primary Channel Access Response frame. By exchanging these Action frames, STA 102 may obtain permission to execute NPCH access based on its own request. For example, when traffic requiring delay is accumulated in the transmission buffer of the STA 102, the STA 102 can actively request permission to execute NPCH access along with the situation.

[0031] (Determining Whether NPCH Access Should Be Executed) As described above, the AP 101 determines whether NPCH access should be executed before transmitting the NPCH Access element. Figure 6 shows the operational flow when the AP 101 determines whether NPCH access should be executed in this processing example. Note that this operational flow is processed by the AP 101 by having the control unit 1302 read and execute a computer program stored in the storage unit 1301 (described later) according to a communication procedure with the STA 102.

[0032] First, the AP 101 checks whether the STA 102 has the capability to perform 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 the 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 the 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 the capability to perform NPCH access based on the capability information acquired from the STA 102 (S603). If the STA 102 does not have the function of executing NPCH access (NO in S603), the AP 101 decides not to use NPCH access between the STA 102 (S608). On the other hand, if the STA 102 has the function of executing NPCH access between the STA 102 (YES in S603), the AP 101 stores the fact that NPCH access can be executed between the STA 102 and the AP 101.

[0033] The AP 101 then determines whether to permit NPCH access. Here, an example will be described in which the AP 101 determines whether to permit NPCH access based on the communication quality of the PCH, the communication quality of the NPCH, and the amount of communication traffic accumulated between the AP 101 and the STA 102. First, the AP 101 determines whether the PCH communication quality is equal to or greater than a threshold (S604). For example, the AP 101 measures the channel utilization rate of the PCH and compares it with a predetermined threshold. As an example, if the measured channel utilization rate exceeds the predetermined threshold, the AP 101 determines that the communication quality of that channel is lower than the threshold. The channel utilization rate can be expressed as the percentage of time per unit time that the channel is busy. If the PCH communication quality is equal to or greater than the threshold (YES in S604), the AP 101 determines not to permit 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 perform 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 determines 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 notification of the accumulation status of the transmission buffer from the STA 102. The AP 101 may also periodically calculate the total or average amount of data accumulated in the AP 101 and the STA 102, and if the temporal change exceeds a predetermined threshold, may determine that the amount of accumulated data is increasing. If the amount of stored data has increased (YES in S606), the AP 101 determines that NPCH access is executable (S607). On the other hand, if the amount of stored data has not increased (NO in S606), the AP 101 determines not to execute NPCH access (S608). The AP 101 notifies the STA 102 whether or not NPCH access is executable. Then, the AP 101 and the STA 102 execute communication based on the determination by the AP 101.

[0034] The method by which the AP 101 determines whether to execute NPCH access is not limited to this example. As an example, the example in FIG. 6 describes a case in which both the communication quality of the PCH and the communication quality of the NPCH are used. However, the AP 101 may determine whether to execute NPCH access based on either the communication quality of the PCH or the communication quality of the NPCH. To evaluate the communication quality of a channel, for example, the channel usage rate may be used. If the PCH usage rate is high due to the presence of multiple nearby wireless networks using the same PCH as the network 103, waiting until the busy PCH becomes idle does not necessarily mean that the right to transmit will be acquired at the next opportunity. Therefore, if the PCH usage rate is high, the AP 101 may determine that NPCH access should be executed. If the PCH usage rate is low, the AP 101 may determine that it should wait until the PCH becomes idle. On the other hand, if the NPCH usage rate is high, the NPCH is likely to be busy frequently, and NPCH access is likely to be unexecutable. Therefore, the AP 101 may determine that it should wait until the PCH becomes idle without performing NPCH access. During this wait, power-saving operation may be performed. Furthermore, if the NPCH usage rate is low, the AP 101 may determine that it should perform NPCH access. By performing NPCH access by the AP 101 and the STA 102, transmission latency is reduced and data transmission delay is alleviated. The channel communication quality may be the signal-to-interference-and-noise ratio (SINR), average throughput, average delay, etc., at the AP 101. Furthermore, the criteria for determining whether or not the AP 101 should perform NPCH access are not limited to the communication quality between the PCH and the NPCH. For example, the AP 101 may determine whether or not to perform NPCH access based on the type of data (application, category, etc.) described below or the presence or absence of other functions such as multilink. The AP 101 may determine whether or not to perform NPCH access by combining the communication quality of these channels and other criteria.

[0035] When determining whether to perform NPCH access based on the communication quality of the channel, the AP 101 performs processing to identify the communication quality of the PCH or the NPCH. For example, the AP 101 may monitor the PCH and identify the PCH usage rate based on the percentage of time per unit time during which signal power exceeding a predetermined threshold is detected. The AP 101 may also identify the SINR from the RSSI of a signal received from the STA 102 communicating with the AP 101 and the RSSI of other signals (i.e., interference signals). Similarly, the AP 101 may identify the communication quality of each NPCH. Furthermore, the AP 101 may have the STA 102 measure the communication quality, obtain the results, and then analyze the communication quality calculated by the AP 101 and the communication quality obtained from the STA 102 to identify the communication quality. As an example, the AP 101 may request the STA 102 to measure the communication quality of the SPCH. The STA 102 may measure the communication quality of the SPCH based on a request from the AP 101 and provide the measurement results to the AP 101. For example, the AP 101 may use a Measurement Request element to request the STA 102 to perform measurements. The Measurement Request element may include information identifying the NPCH on which measurements should be performed, the items to be measured, the measurement period (measurement start time, measurement end time, etc.), the number of measurements, the measurement period, etc. For example, if multiple SPCHs are configured in the NPCH, the AP 101 may specify whether all SPCHs, some SPCHs, or all NPCHs should be measured. For example, the AP 101 may specify the NPCHs to be measured using a bitmap corresponding to each channel of the NPCH. In this case, bits corresponding to the NPCHs to be measured may be set to 1, and bits corresponding to the NPCHs not to be measured may be set to 0. The AP 101 may perform measurements on all NPCHs and reset the NPCH with the highest communication quality as the SPCH. On the other hand, limiting the measurement targets reduces the load on the STAs 102 that perform the measurements. The STAs 102 that have performed the measurements may notify the AP 101 of the measurement results using, for example, a Measurement Report element.As an example, the Measurement Report may include information identifying the NPCH on which the measurement was performed, the measurement results, the measurement period, the number of measurements, the measurement cycle, etc. The measurement items or measurement results may be the channel utilization rate, 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 results are not limited to the above. Furthermore, the AP 101 may request the STA 102 to measure the communication quality of the PCH, similar to the measurement of the communication quality of the NPCH.

[0036] The AP 101 may request the STAs 102 to notify the STAs 102 of the accumulated communication traffic status. The AP 101 may determine whether 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 via NPCH access, the AP 101 may cause the STAs 102 to transmit the accumulated communication traffic early, thereby mitigating degradation of delay characteristics. The AP 101 may also permit NPCH access only to STAs 102 whose communication traffic exceeds a threshold. In this case, the AP 101 may notify each STA 102 of the NPCH Access element using an Action frame.

[0037] (NPCH Access by Communication Device) The STA 102 determines whether or not to execute NPCH access based on information regarding whether or not NPCH access can be executed notified from the AP 101, 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 execution of NPCH access is permitted, and if this value is 0, the STA 102 may determine that execution of NPCH access is prohibited. The STA 102 also 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.

[0038] FIG. 7 shows an example of a flow when the communication device 100 transmits data in this embodiment. When the STA 100 detects that data has accumulated in its transmission queue (S701), it initiates a channel access procedure to transmit this data. First, the STA 102 performs carrier sensing on the PCH (S702). For example, the STA 102 measures a backoff counter on the PCH and determines whether the PCH is in an idle state. If the STA 102 determines that the PCH is in an idle state (YES in S703), the STA 102 transmits a signal using one or more channels including the PCH (S704). Note that after determining that the PCH is in an idle state, the STA 102 may perform carrier sensing on the NPCH for a predetermined period of time. Furthermore, the STA 102 may perform carrier sensing on the NPCH in parallel with carrier sensing on the PCH. The STA 102 may determine a channel to use for transmission based on the results of carrier sensing performed on the PCH and the 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.

[0039] On the other hand, when the STA 102 detects a signal on the PCH during carrier sensing (NO in S703), it sets the NAV for the PCH using the duration indicated in the Duration field included in the received signal. The STA 102 then checks whether NPCH access is permitted. For example, if NPCH access is prohibited (NO in S705), the STA 102 waits until the PCH enters an idle state (S706). On the other hand, if NPCH access is permitted (YES in S705), the STA 102 determines whether the signal detected on the PCH is transmitted from a communication device belonging to the network 103. For example, the STA 102 can determine whether the signal is from its own BSS or an OBSS based on whether the BSS Color field included in the received signal matches the BSS Color of its own BSS. Furthermore, STA 102 can determine whether a received signal is from its own BSS or from an OBSS based on whether the values ​​stored in the destination field, source field, etc. included in the signal match the parameters of its own BSS. For example, if the signal detected on the PCH is a signal from the OBSS (YES in S707), STA 102 executes NPCH access. On the other hand, if the signal detected on the PCH is a signal from its own BSS (NO in S707), STA 102 determines not to execute NPCH access and waits until the PCH becomes idle (S706).

[0040] When the STA 102 performs NPCH access, it performs carrier sensing on the SPCH. If it does not detect a signal on the SPCH, it measures a backoff counter in the same manner as in carrier sensing on the PCH, and determines whether the SPCH is in an idle state. If it determines that the SPCH is in an idle state (YES in S708), the STA 102 transmits a signal using one or more NPCHs, including the SPCH (S709). Note that after determining that the SPCH is in an idle state, the STA 102 may perform carrier sensing on other NPCHs for a predetermined period of time. Based on the results of carrier sensing performed on the SPCH and other NPCHs, the STA 102 may determine a channel to use for transmission and transmit a signal. On the other hand, if the STA 102 detects a signal on the SPCH (NO in S708), it cancels NPCH access and postpones transmission until the NAV period set on the PCH expires (S706). If multiple SPCHs are configured, the STA 102 may continue the NPCH access procedure until it confirms that all SPCHs are busy. If all SPCHs are busy, the STA 102 postpones transmission until the NAV period set in the PCH expires. Even if NPCH access is permitted, the STA 102 may postpone transmission until the NAV period of the PCH expires without performing NPCH access. For example, the STA 102 may postpone transmission until the NAV period of the PCH expires without performing NPCH access if the remaining battery charge of the STA 102 is below a threshold or if the STA 102 is configured by a user input not to perform NPCH access. In this case, the STA 102 may perform the minimum reception operation required for transmission using NPCH access that can be performed by the AP 101. For example, the STA 102 may operate only a processing circuit capable of detecting a received signal on the SPCH and operate other circuits in a power-saving mode.

[0041] 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, an Association Response, and the like are exchanged between the devices. Capability information related to NPCH access is shared with each other using a UHR Capabilities element and the like included in the Association Request and Association Response, and the connection process is completed (F803). The AP 101 and the STA 102 transmit and receive data based on the NPCH access capability information notified or acquired from each other and a determination of whether NPCH access can be performed. For example, when 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 NPCH access is permitted, the AP 101 and the STA 102 select either the first communication method or the second communication method depending on the PCH status. For example, when NAV is set for the PCH, the AP 101 and the STA 102 communicate using the NPCH access (second communication method) (F806, F807).

[0042] As described above, in this embodiment, when the AP 101 and the STA 102 can communicate using NPCH access, the AP 101 determines whether to execute NPCH access and notifies the STA 102 of the determination result. Based on the notification, the AP 101 and the STA 102 determine whether to execute NPCH access and select a communication method to use for communication. This enables 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.

[0043] [Processing Example 2] In Processing Example 1, the AP 101 determines whether or not to execute NPCH access, and the STA 102 determines the communication method to use in communication based on the result of the determination. In this processing example, the AP 101 generates conditions to be satisfied when executing NPCH access and notifies the STA 102. For example, the AP 101 may use, as conditions to be satisfied when executing 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.

[0044] FIG. 9 shows an operational flow in which the AP 101 in this processing example generates conditions to be satisfied when executing NPCH access and notifies the STA 102 of the conditions. In the example shown in FIG. 9, the AP 101 enables NPCH access on the condition that the communication traffic has a predetermined delay requirement. That is, the AP 101 permits NPCH access for traffic with a delay requirement, such as voice data or image data, thereby controlling the data so that the delay requirement is met even when the PCH is congested. Note that traffic with a delay requirement may include time-critical data such as robot control, or data that affects the user experience, such as print jobs and photo sharing. In the operational flow of FIG. 9, operations common to FIG. 6 are assigned the same reference numerals and will not be described again. First, the AP 101 executes steps S601 to S603 to confirm whether the STA 102 has the capability to execute NPCH access. Then, the AP 101 determines whether the traffic communicating with the STA 102 includes traffic with a delay requirement (S901). For example, the AP 101 may determine whether the traffic communicating with the STA 102 includes traffic requiring a delay based on a traffic type identifier (TID) or access category assigned to the traffic. The AP 101 may also determine whether the traffic requires a delay based on communication parameters exchanged during negotiation or the like with the STA 102. If the traffic requiring a delay is included in the communication with the STA 102 (YES in S901), the AP 101 may notify the STA 102 that NPCH access is possible under the condition that the traffic corresponds to the traffic (S902). On the other hand, if the traffic requiring a delay is not included (NO in S901), the AP 101 may notify the STA 102 that NPCH access is not possible (S608).

[0045] As an example, Figure 10 shows an example of an information element for notifying conditions that must be met when executing 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 Figure 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 optionally include an NPCH Access Parameter Update field 405. In Figure 10, fields that have the same functions as those in Figure 4 are assigned the same reference numbers, and their description will be omitted. That is, the difference between the information elements in FIG. 10 and those 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 that must be satisfied when executing NPCH access generated in the AP 101. For example, FIG. 10 shows an example in which the condition that must be satisfied when executing NPCH access is that the traffic to be communicated corresponds to a predetermined type. Here, each bit constituting the NPCH Access Operation field 1001 can correspond to a TID (Traffic Identifier) ​​that identifies the type of traffic to be communicated. For example, the TID can 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 (e.g., print job, photo share, etc.). The AP 101 may also classify the type of traffic being 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.In this embodiment, the AP 101 determines whether NPCH access is possible for each TID and sets a bit corresponding to each TID. For example, the AP 101 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 0. The AP 101 may control the NPCH access for traffic with a delay requirement, such as voice traffic or video traffic, so that such traffic can be transmitted early even when the PCH is unavailable. The AP 101 may also control the NPCH access to be permitted for traffic that affects the user experience, such as print jobs or photo sharing.

[0046] FIG. 11 shows an example of a flow when the STA 102 transmits data in this processing example. In FIG. 11, operations common to those in FIG. 7 are assigned the same reference numerals, and description thereof will be omitted. When the STA 102 detects that data has been stored in the STA 102, the STA 102 performs carrier sensing on the PCH and determines the signal detection status on the PCH (S701 to S703). If the PCH is busy, the STA 102 determines whether the data to be transmitted satisfies the conditions for executing NPCH access (S1101). For example, the STA 102 acquires the conditions to be satisfied when executing NPCH access by receiving an NPCH Access Operation field 1001 included in a Beacon frame received from the AP 101. Furthermore, for example, the STA 102 determines whether the TID of the data stored in the STA 102 is a TID for which NPCH access is permitted, thereby determining whether the conditions to be satisfied when executing NPCH access are satisfied. When the STA 102 determines that the TID of the data stored in the STA 102 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 met (NO in S1101), the STA 102 does not execute NPCH access (S706).

[0047] The AP 101 may use conditions other than communication traffic with a predetermined delay requirement as conditions to be satisfied when performing NPCH access. As an example, the AP 101 may set, as a condition to be satisfied when performing NPCH access, that the communication quality of the channel used for NPCH access is equal to or greater than a predetermined threshold. For example, the AP 101 may set, as parameters for determining the communication quality of the channel, the RSSI of the signal received from the AP 101 at the STA 102, the SINR at the STA 102, the packet error rate, the packet retransmission rate, the channel usage rate, etc. For example, if the RSSI or SINR is low or if 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 granting NPCH access to STAs with a high possibility of successful communication, it is possible to effectively use frequency resources. The AP 101 may store and transmit thresholds such as RSSI, SINR, packet error rate, packet retransmission rate, and channel utilization rate in the NPCH Access Operation field 1001. By receiving the NPCH Access Operation field 1001, the STA 102 acquires various thresholds as conditions that must be met when performing NPCH access. The STA 102 compares the RSSI of the signal received from the AP 101 or the SINR calculated using the RSSI of the interference signal with these thresholds to determine whether the conditions that must be met when performing NPCH access are met. The STA 102 may also compare the error rate and retransmission rate measured for a signal transmitted by the STA 102 using the PCH or NPCH with these thresholds to determine whether the conditions that must be met when performing NPCH access are met. The STA 102 may measure the channel utilization rate of the SPCH and compare it with a threshold value to determine whether the conditions to be met when performing NPCH access are met. Note that, since signals that can be received on the SPCH differ depending on the physical location of each communication device, the channel utilization rates measured by each STA may differ from one another.The AP 101 provides a threshold value and each STA makes an individual decision, thereby controlling the STA to perform NPCH access preferentially with a high probability of success.

[0048] Note that the conditions that can be applied as conditions to be satisfied when the AP 101 executes NPCH access are not limited to those described above. For example, the AP 101 may use the traffic accumulation status of the STA 102 as a condition to be satisfied when executing NPCH access. As an example, the AP 101 may notify the STA 102 of thresholds such as the amount of data accumulated in the transmission buffer or the number of packets as a condition to be satisfied when executing NPCH access. By controlling the STA with a large amount of communication traffic to execute NPCH access preferentially, traffic congestion in that STA may be alleviated. In this case, the AP 101 may store thresholds 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 of the thresholds.

[0049] As described above, in this embodiment, the AP 101 generates conditions to be satisfied when performing NPCH access and notifies the STA 102 of the conditions. The STA 102 determines whether or not to perform NPCH access by determining whether its own device or its traffic satisfies the notified conditions. By having STAs that need to transmit data early or STAs that are relatively likely to achieve successful communication perform NPCH access, it becomes possible to use frequency resources effectively. Note that the conditions to be satisfied when performing NPCH access may be a combination of the above conditions. Alternatively, conditions other than those described above may be used. In this case, the NPCH Access Operation field 1001 may have the same number of fields as the number of conditions. Note that the NPCH Access Operation field 1001 may be transmitted using an Action frame. In this case, an NPCH Access Operation field 1001 is stored instead of the NPCH Access Mode field 406 in FIG. 5 . When a Beacon frame is used to notify conditions that must be satisfied when periodically performing NPCH access, the information is transmitted periodically even when the conditions remain unchanged. By using an Action frame, it is possible to notify only when there is a change in the conditions, thereby enabling efficient use of frequency resources. Furthermore, the NPCH Access Mode field 406 and the NPCH Access Operation field 1001 may be included in a single 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 enabled. 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, which makes it possible to reduce the processing load.

[0050] [Processing Example 3] The IEEE 802.11be 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 perform multi-link communication in addition to NPCH access, the communication device 100 can use multi-link communication and NPCH access in parallel. This processing example provides a function that determines whether to use NPCH access based on whether the AP 101 and the STA 102 can perform multi-link communication.

[0051] 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 by, for example, AP 101. Note that this flow may also be executed by STA 102, or may be executed while communicating between AP 101 and STA 102. Below, this flow will be described as an example executed by AP 101. First, AP 101 determines whether or not STA 102 has the capability to execute NPCH access (S1201). For example, in the procedure for establishing a link with STA 102, AP 101 may confirm whether or not STA 102 has the capability to execute NPCH access by exchanging a Capabilities element, etc. If STA 102 does not have the capability to execute NPCH access (NO in S1201), AP 101 determines not to use NPCH access (S1206). On the other hand, if the STA 102 has the function of performing NPCH access (YES in S1201), the AP 101 determines whether a multilink connection has been established with the STA 102 (S1202). For example, the AP 101 can determine whether a multilink connection has been established by checking whether multiple links have already been established with the STA 102 or whether only one link has been established. If a multilink connection has not been established (NO in S1202), the AP 101 determines not to use NPCH access (S1206). On the other hand, if a multilink connection has been established (YES in S1202), the AP 101 determines whether communication can be performed using 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 simultaneously and independently transmitted and received between multiple links that do not interfere with each other. In other words, if the AP 101 can use the link using the NPCH access and other links independently, it can communicate information necessary for controlling the NPCH access using the other links. On the other hand, if STR communication is not possible on these links, there is a possibility that communication on the other links and the NPCH access may be subject to interference or restrictions.If multi-link communication is not possible using the STR method (NO in S1203), the AP 101 determines not to use NPCH access (S1206). On the other hand, if multi-link communication is possible using the STR method (YES in S1203), the AP 101 determines whether or not additional links can be added (S1204). For example, if additional links can be added, adding a new link can enable necessary communication without using NPCH access. The AP 101 can determine whether or not to add a new link by, for example, checking whether the AP 101 has wireless processing functions that can be used to establish a new link in addition to the wireless processing functions used for multi-link communication already established with the STA 102. If additional links cannot be added (YES in S1204), the AP 101 determines to use NPCH access (S1207). On the other hand, if additional links can be added (YES in S1204), the AP 101 determines whether the bandwidth of the additional link is narrower than the bandwidth of the existing link (S1205). If the bandwidth of the link that can be added is narrower than the bandwidth of the existing link, it may be possible to perform faster communication by using NPCH access. If the bandwidth of the link that can be added is narrower than the bandwidth of the existing link (YES in S1205), AP 101 determines to use NPCH access (S1207). On the other hand, if the bandwidth of the link that can be added is wider than the bandwidth of the existing link (NO in S1205), AP 101 determines to use NPCH access (S1206).

[0052] As described above, in this processing example, when multilink communication and NPCH access can be used in parallel between communication devices, whether to use NPCH access is determined based on interference between multilink communication and NPCH access and the bandwidth available for each. This makes it possible to improve frequency utilization efficiency while avoiding interference and limitations between multilink communication and NPCH access. The method of determining whether to use NPCH access when multilink communication and NPCH access can be used in parallel between communication devices is not limited to this. Whether to execute multilink communication and NPCH access may be dynamically determined depending on the communication quality and traffic conditions of each link of the multilink. Furthermore, whether to execute NPCH access may be switched for each link of the multilink.

[0053] 13 shows an example of the hardware configuration of the communication device 100 (AP 101 and STA 102) according to 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.

[0054] The storage unit 1301 is configured with one or more memories including ROM, RAM, etc., and may store various information such as control programs for each functional unit constituting the communication device 100 to perform various operations, and parameters for communication. ROM and RAM stand for Read Only Memory and Random Access Memory, respectively. The storage unit 1301 may be configured to include, in addition to memories such as ROM and RAM, storage media such as a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, and a DVD.

[0055] 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. If the control unit 1302 has multiple processors that can be implemented using a multi-core or the like, the entire communication device 100 may be configured to be controlled by the multiple processors.

[0056] The control unit 1302 also controls the functional unit 1303 to perform predetermined processes such as communication, image capture, printing, and projection. The functional unit 1303 is hardware that enables the communication device 100 to perform the predetermined processes described above. For example, if the device is a camera, the functional unit 1303 is an image capture unit that performs image capture processing. For example, if the device is a printer, the functional unit 1303 is a print unit that performs print processing. For example, if the device is a projector, the functional unit 1303 is a projection unit that performs projection processing.

[0057] The input unit 1304 receives various operations from the user. The output unit 1305 outputs various types of information to the user via a monitor screen or a speaker. The output from the output unit 1305 may be a display on a monitor screen, an audio output from a speaker, a vibration output, or the like. The input unit 1304 and the output unit 1305 may both be implemented as a single module, such as a touch panel. The input unit 1304 and the output unit 1305 may be integrated into the communication device 100 or may be separate devices.

[0058] The communication unit 1306 controls wireless communication compliant with the IEEE 802.11bn standard. Furthermore, the communication unit 1306 may control wireless communication compliant with other IEEE 802.11 standard series, such as legacy standards, in addition to the IEEE 802.11bn standard. The communication unit 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 if the communication device 100 supports other wireless communication standards, such as the NFC standard or the Bluetooth standard, or wired communication such as a wired LAN, in addition to the IEEE 802.11bn standard, the communication unit 1306 may control communication compliant with these communication standards. Furthermore, if the communication device 100 can perform wireless communication compliant with multiple communication standards, the communication device 100 may be configured to have separate communication units and antennas corresponding to each communication standard. Communication device 100 communicates data with a partner communication device via communication unit 1306. Antenna 1307 may be configured as a separate unit from communication unit 1306, or may be configured as a single module together with communication unit 1306. When communication device 100 is configured to simultaneously perform carrier sensing of multiple SPCHs, communication device 100 may include as many communication units 1306 as necessary for this purpose.

[0059] 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. Although Fig. 13 shows a configuration in which communication device 100 has two antennas 1307, communication device 100 may have one or three or more antennas, or may have one or more antennas for each frequency band that the device can use. Furthermore, if communication device 100 has multiple antennas, communication device 100 may have a communication unit 1306 for each antenna.

[0060] 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, for example, by one or more processors executing programs 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.

[0061] The frame control unit 1401 generates a signal (frame) when communicating with a partner communication device. The frame control unit 1401 generates, for example, 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 the STA 102 of whether or not NPCH access can be performed and of conditions that must be met when performing NPCH access. The frame control unit 1401 may also generate an Action frame including an NPCH Operating Mode Notification frame Action field. The frame control unit 1401 also generates a frame for requesting information (second information) that the AP 101 can use to determine whether or not NPCH access can be performed and to generate conditions that must be met when performing NPCH access. For example, the frame control unit 1401 can generate an Action frame including a Measurement Request element. Meanwhile, the frame control unit 1401 generates a frame for the STA 102 to provide the AP 101 with information that the AP 101 can use to determine whether or not to perform NPCH access and to generate conditions that must be satisfied when performing NPCH access. For example, the frame control unit 1401 can generate an Action frame that includes a Measurement Report element.

[0062] The NAV detection unit 1402 sets the NAV of the PCH or SPCH based on the Duration value extracted by the frame analysis unit 1406. The wireless communication control unit 1403 performs transmission processing for each frame generated by the frame control unit 1401. The wireless communication control unit 1403 also notifies the frame analysis unit 1406 of frames received via the antenna 1307. For example, the wireless communication control unit 1403 may transmit or receive data frames 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. If a signal is detected on the PCH or if the NAV detection unit 1402 sets the NAV, the wireless communication control unit 1403 may perform carrier sense of the SPCH based on the determination by the NPCH access condition determination unit 1405 of whether NPCH access is possible. For example, if the wireless communication control unit 1403 does not detect a signal on the SPCH and the NAV detection unit 1402 does not set a NAV on the SPCH, the wireless communication control unit 1403 transmits a data frame using one or more NPCHs including the SPCH. The SPCH control unit 1404 performs setting and control for performing NPCH access. For example, the SPCH control unit 1404 sets the SPCH channel number, the priority order for performing carrier sense, and the like based on parameters included in the NPCH Access Parameter Update field 405. Note that the SPCH control unit 1404 may perform 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 determines whether or not NPCH access can be performed and generates conditions that must be satisfied when performing NPCH access, based on the communication quality of the NPCH and the traffic accumulation status in the STA 102. The NPCH access condition determination unit 1405 also requests second information from the STA 102 that is required for determining whether or not NPCH access can be performed and for generating conditions that must be satisfied when performing NPCH access.The NPCH access condition determination unit 1405 in the STA 102 determines whether or not NPCH access is permitted based on first information extracted from the NPCH Access element, etc. The NPCH access condition determination unit 1405 also provides the AP 101 with second information necessary for the AP 101 to determine whether or not NPCH access is permitted and to generate conditions that must be satisfied when performing NPCH access. The frame analysis unit 1406 can acquire information necessary for communication by analyzing frames received from the other communication device. For example, the frame analysis unit 1406 in the STA 102 acquires information (first information) usable for determining whether or not NPCH access is permitted from a Beacon frame or an Action frame. The frame analysis unit 1406 in the AP 101 also acquires information (second information) usable for determining whether or not NPCH access is permitted from an Action frame including a Measurement Report element. The second information may also be used to generate conditions that must be satisfied when performing NPCH access. The frame analyzer 1406 may acquire the value of Duration by analyzing the received frame and notify the NAV detector 1402 of the value.

[0063] As described above, according to the present embodiment, even when the PCH is unavailable, communication using the NPCH is performed based on carrier sensing in the SPCH. This enables efficient use of link frequencies and increases the communication capacity provided by the wireless communication system. Furthermore, according to the present embodiment, whether or not to perform NPCH access is determined based on the communication quality of the PCH and NPCH, the traffic accumulation status in the communication device, and the like. This enables appropriate communication according to the situation, such as performing NPCH access when the success rate of NPCH access is high or when early communication is necessary, and performing power-saving operation in other cases. While the present embodiment illustrates communication between the AP 101 and the STA 102, the present technology may also be applied between multiple STAs. Furthermore, while the present embodiment illustrates a case where a communication method that does not use the PCH is referred to as NPCH access, this is not limited thereto and may be referred to, for example, as secondary primary channel access. Although the present embodiment illustrates a case where a channel for determining whether or not to transmit using the NPCH is referred to as SPCH for convenience, this is not limited thereto. Among multiple secondary channels, the PSCH may be referred to as a Primary Secondary Channel (PSCH), meaning that it is a channel with a high priority for determining whether transmission is possible. Regardless of which term is used, it means that it is a channel to be used for determining whether transmission using the NPCH is possible. Furthermore, the names of the information elements and various fields in this embodiment may be referred to by other names. In this embodiment, an example has been shown in which whether NPCH access is possible is determined depending on the communication quality of the channel and the traffic accumulation status in the communication device, but whether NPCH access is possible may also be determined based on information other than these.

[0064] The present invention can also be realized by supplying a program that realizes one or more of the functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., an ASIC) that realizes one or more of the functions.

[0065] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

[0066] This application claims priority based on Japanese Patent Application No. 2023-178386, filed on October 16, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A communications device capable of communicating using a first channel access method that uses at least a primary channel in one link, and a second channel access method that does not use the primary channel when the primary channel is busy, and uses at least one non-primary channel different from the primary channel among multiple channels included in the link, the communications device having a function of performing communications using the second channel access method, a notification means for notifying the other communications device having a function of performing communications using the second channel access method of first information that can be used by the other communications device to determine whether or not it is permitted to perform communications using the second channel access method, and a communication means for communicating with the other communications device that has received the first information.

2. The communication device according to claim 1, characterized in that the first channel access method is a primary channel access method in which access to the channel is made based on the result of carrier sense for the primary channel, and the second channel access method is a non-primary channel access method in which access to the channel is made based on the result of carrier sense for the non-primary channel.

3. The communication device according to claim 1, characterized in that the primary channel is a primary channel defined based on one standard in the IEEE 802.11 standard series, and the non-primary channel is a non-primary channel defined based on at least one standard in the IEEE 802.11 standard series.

4. 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 using the second channel access method.

5. The communication device according to claim 1, wherein said first information includes information indicating a condition to be satisfied when said other communication device performs communication using said second channel access method.

6. The communication device according to claim 1, wherein said notification means periodically notifies said first information using a Beacon frame defined in the IEEE 802.11 standard series.

7. The communication device according to claim 1, wherein the notification means notifies the first information using an Action frame defined in the IEEE 802.11 standard series.

8. A communication device according to any one of claims 1 to 7, further comprising an acquisition means for acquiring second information usable for generating said first information from said other communication device.

9. The communication device according to claim 8, wherein the second information includes information for identifying communication quality in the non-primary channel.

10. The communication device according to claim 8, wherein the second information includes information for identifying an accumulation status of communication traffic in the other communication device.

11. A communications device capable of communicating using a first channel access method that uses at least a primary channel in one link, and a second channel access method that does not use the primary channel when the primary channel is busy, and uses a non-primary channel different from the primary channel among multiple channels included in the link, comprising: an acquisition means for acquiring first information from another communications device that can be used to determine whether or not communications using the second channel access method may be executed; a determination means for using the first information to determine whether or not communications using the second channel access method may be executed; and a communication means for communicating data with the other communications device based on a result of the determination.

12. The communication device according to claim 11, characterized in that the first channel access method is a primary channel access method in which access to the channel is made based on a result of carrier sense for the primary channel, and the second channel access method is a non-primary channel access method in which access to the channel is made based on a result of carrier sense for the non-primary channel.

13. The communication device according to claim 11, wherein the primary channel is a primary channel defined based on one standard in the IEEE 802.11 standard series, and the non-primary channel is a non-primary channel defined based on at least one standard in the IEEE 802.11 standard series.

14. The communication device according to claim 11, wherein the first information includes information indicating whether the communication device is permitted or prohibited from performing communication in a second channel access method.

15. The communication device according to claim 11, wherein the first information includes a condition to be satisfied when the communication device performs communication in a first channel access method.

16. The communication device according to any one of claims 11 to 15, wherein the acquisition means periodically acquires the first information from a Beacon frame defined in the IEEE 802.11 standard series.

17. The communication device according to any one of claims 11 to 15, wherein the acquisition means acquires the first information from an Action frame defined in the IEEE 802.11 standard series.

18. A communication device according to any one of claims 11 to 17, further comprising providing means for providing second information usable by said other communication device to generate said first information to said other communication device.

19. The communication device according to claim 18, wherein the second information includes information for identifying communication quality in the non-primary channel.

20. The communication device according to claim 18, wherein the second information includes information for identifying an accumulation status of communication traffic in the communication device.

21. A control method executed by a communication device capable of communicating using a first channel access method that uses at least a primary channel in one link, and a second channel access method that does not use the primary channel when the primary channel is busy, and uses at least one non-primary channel different from the primary channel among multiple channels included in the link, comprising: a notification step of notifying another communication device having a function of executing communication using the second channel access method of first information that can be used by the other communication device to determine whether or not it is permitted to execute communication using the second channel access method; and a communication step of communicating with the other communication device that has received the first information.

22. A method executed by a communication device capable of communicating using a first channel access method that uses at least a primary channel in one link, and a second channel access method that does not use the primary channel when the primary channel is busy, and uses a non-primary channel different from the primary channel among multiple channels included in the link, comprising: an acquisition step of acquiring first information from another communication device that can be used to determine whether or not communication using the second channel access method may be executed; a determination step of using the first information to determine whether or not communication using the second channel access method may be executed; and a communication step of communicating data with the other communication device based on a result of the determination.

23. A program for causing a computer included in a communications device capable of communicating using a first channel access method that uses at least a primary channel in one link, and a second channel access method that does not use the primary channel when the primary channel is busy, and uses at least one non-primary channel different from the primary channel among multiple channels included in the link, to notify another communications device having a function of performing communications using the second channel access method of first information that can be used by the other communications device to determine whether or not it is permitted to perform communications using the second channel access method, and to communicate with the other communications device that has received the first information.

24. A program for causing a computer included in a communications device capable of communicating using a first channel access method that uses at least a primary channel in one link, and a second channel access method that does not use the primary channel when the primary channel is busy, and uses a non-primary channel different from the primary channel among multiple channels included in the link, to obtain first information from another communications device that can be used to determine whether or not communications using the second channel access method may be executed, use the first information to determine whether or not communications using the second channel access method may be executed, and communicate data with the other communications device based on the result of the determination.

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