Communication device, communication method, and program

Abstract

Efficient use of frequency resources between the transmitting and receiving communication devices. [Solution] A communication device operating as an access point that communicates with other communication devices using wireless frames compliant with the IEEE 802.11 standard series notifies the other communication device of reference information used to determine whether to select a second or third communication method when a wireless frame transmitted by another BSS (Basic Service Set) is detected on the first channel, and when the first channel detects a wireless frame transmitted by another BSS, it determines the communication method to use based on the reference information and performs communication.

Description

Technical Field

[0001] The present invention relates to a control technique that enables efficient use of frequency resources in a wireless communication system.

Background Art

[0002] In recent years, with the increase in the amount of data to be communicated, the development of communication technologies such as wireless LAN (Local Area Network) has been progressing. As the main communication standards for wireless LAN, the IEEE (Institute of Electrical and Electronic Engineers) 802.11 standard series is known. The IEEE 802.11 standard series includes IEEE 802.11a / b / g / n / ac / ax / be standards and the like. For further improvement of communication reliability, the development of the IEEE 8^{th}02.11bn standard is underway as a successor standard to the IEEE 802.11be standard.

[0003] In the IEEE 802.11ax standard, as a technique for improving the frequency utilization efficiency, an SR function has been introduced in which a plurality of BSSs communicate simultaneously using the same frequency by spatially partitioning between Basic Service Sets (BSSs). SR is an abbreviation for Spatial Reuse. For example, in Patent Document 1, it is described that when a signal other than the BSS to which the own device belongs is received, carrier sensing is performed using different signal detection levels according to the received signal.

[0004] On the other hand, in the IEEE 802.11bn standard, as a technique for improving the frequency utilization efficiency, NPCA that communicates using a Non-Primary Channel when the Primary Channel for obtaining the transmission right is busy is being considered. NPCA is an abbreviation for Non-Primary Channel Access.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] U.S. Patent Application Publication No. 20160374087 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In wireless communication systems that communicate in accordance with the IEEE 802.11bn standard, communication can be performed while dynamically selecting between communication using SR and communication using NPCA as described above. The present invention provides a technology that enables efficient use of frequency resources by appropriately selecting between communication using SR and communication using NPCA between the transmitting communication device and the receiving communication device. [Means for solving the problem]

[0007] A communication device according to one aspect of the present invention is a communication device that operates as an access point for communicating with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, and comprises a first communication method configured to enable communication by bonding a first channel and a second channel different from the first channel, the first communication method which performs communication on the first channel without using the Spatial Reuse function based on the fact that wireless frames transmitted in a Basic Service Set (BSS) different from the one configured by the communication device are not detected on the first channel, and the first communication method which performs communication on the first channel without using the Spatial Reuse function based on the fact that wireless frames transmitted in the other BSS are detected on the first channel Communication means for communicating with the other communication device using a plurality of communication methods, including a second communication method that uses a reuse function to communicate, and a third communication method that uses the second channel without using the first channel based on the detection of a wireless frame transmitted by the other BSS on the first channel, and notification means for notifying reference information used by the other communication device to determine which of the second and third communication methods to select when a wireless frame transmitted by the other BSS is detected on the first channel, wherein when the communication means detects a wireless frame transmitted by the other BSS on the first channel, it determines the communication method to be used based on the reference information and performs communication. [Effects of the Invention]

[0008] According to the present invention, frequency resources can be used efficiently between communication devices. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing an example configuration of a wireless communication system. [Figure 2] This figure shows an example of a time chart for when a communication device transmits data. [Figure 3]This diagram shows an overview of the communication method using SR. [Figure 4] This figure shows an example of a time chart in a communication method using SR. [Figure 5] This figure shows an example of the correspondence between the Uplink Spatial Reuse field, the Spatial Reuse field values, and the content that those values ​​represent. [Figure 6] This figure shows an example of the hardware configuration of a communication device. [Figure 7] This figure shows an example of the AP's functional configuration. [Figure 8] This figure shows an example of the functional configuration of STA. [Figure 9] This figure shows an example of a message sequence exchanged between the AP and STA. [Figure 10] This figure shows an example of a processing flow for selecting between communication using SR or communication using NPCA. [Figure 11] This figure shows an example of a processing flow for determining whether or not to execute communication using SR. [Figure 12] This figure shows an example of a processing flow for determining whether or not to execute communication using NPCA. [Figure 13] This is a diagram showing an example of a PPDU configuration. [Figure 14] This figure shows an example of a processing flow for analyzing received frames. [Figure 15] This figure shows an example of a processing flow executed by the AP. [Figure 16] This figure shows an example of the processing flow executed by STA. [Figure 17] This figure shows an example configuration for Spatial Reuse Parameter set IE. [Figure 18] This figure shows an example sequence of messages exchanged between the AP and STA of OBSS. [Figure 19] This figure shows an example sequence of messages exchanged between the AP and STA of OBSS. [Figure 20]This is a diagram showing an example sequence including messages exchanged between an AP and an AP of OBSS. [Figure 21] This is a diagram showing an example processing flow executed by the AP of OBSS. [Figure 22] This is a diagram showing an example processing flow executed by the AP of OBSS. [Figure 23] This is a diagram showing an example processing flow executed by the STA of OBSS.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are given the same reference numerals, and duplicate descriptions are omitted.

[0011] (System Configuration) Figure 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) 111. AP101 and STA111 are communication devices capable of performing wireless communication compliant with the IEEE 802.11 standard series. IEEE is an abbreviation for Institute of Electrical and Electronics Engineers. Figure 1 shows a configuration in which STA111 participates in network 121, which is configured by AP101. Network 121 may also be called a Basic Service Set (BSS). Also in Figure 1, there is a network 122, configured by AP102 and STA112, in the vicinity of network 121. AP102 and STA112 are communication devices capable of performing wireless communication compliant with the IEEE 802.11 standard series, similar to AP101 and STA111. For AP101 and STA111, network 121 is the BSS to which their devices connect, and may be called their own BSS. On the other hand, for AP101 and STA111, network 122 is a network that can interfere with their own BSS and may be called an Overlapping BSS (OBSS). The following description will mainly focus on AP101 and STA111, but the same description may also apply to AP102 and STA112. Similarly, the description of AP102 and STA112 may also apply to AP101 and STA111. For example, AP101 may have the functions described for AP101 and the functions described for AP102. Similarly, STA111 may have the functions described for STA111 and the functions described for STA112. In this embodiment, AP101 and STA111 are sometimes collectively referred to as communication device 100. Figure 1 shows a configuration in network 121 where there is one AP and one STA, but for example, there may be multiple APs and STAs in network 121. Furthermore, at that time, each STA may connect to one AP, or one STA may connect to multiple APs.

[0012] In this embodiment, the communication device 100 is configured to execute a communication method compliant with the IEEE 802.11bn standard. The IEEE 802.11bn standard is the successor to the IEEE 802.11be standard, which aims for a maximum transmission speed of 46.08 Gbps (Gigabit 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 compliant with this standard may be called UHR (Ultra High Reliability) PPDU. PPDU is an abbreviation for PLCP Protocol Data Unit, and PLCP is an abbreviation for Physical Layer Convergence Protocol. Note that the names UHR and IEEE 802.11bn may be changed to other names when the development of this standard is completed. Furthermore, it should be noted that this specification and the claims attached herein are applicable to communication devices using any successor standard to IEEE 802.11be. A successor standard to IEEE 802.11be may be a standard released after the release of the IEEE 802.11be standard. Also, the communication device 100 may support at least one of the legacy standards prior to the IEEE 802.11bn standard. Legacy standards include, for example, the IEEE 802.11a / b / g / n / ac / ax / be standards. The communication device 100 may also support other communication standards such as Bluetooth®, Bluetooth LE (Low Energy), NFC, UWB, ZigBee, and MBOA. UWB is an abbreviation for Ultra Wide Band, and MBOA is an abbreviation for Multi Band OFDM Alliance. NFC is an abbreviation for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, etc. Furthermore, the communication device 100 may support communication standards such as wired LANs using Ethernet cables or optical fibers.The communication device 100 may support cellular communication standards such as 5G and LTE as defined by the 3rd Generation Partnership Project (3GPP®). 5G is an abbreviation for fifth-generation mobile communication system. LTE is an abbreviation for Long Term Evolution.

[0013] AP101 is, for example, a wireless LAN router or a personal computer (PC), but is not limited to these. AP101 may be an information processing device such as a wireless chip capable of performing wireless communication compliant with the IEEE 802.11bn standard. STA111 is, for example, a camera, tablet, smartphone, PC, mobile phone, video camera, headset, smart glasses, HMD (head-mounted display), or other wearable device, but is not limited to these. STA111 may be an information processing device such as a wireless chip capable of performing wireless communication that supports the transmission and reception of PPDU compliant with the IEEE 802.11bn standard. In this case, the wireless chip can be configured to perform various controls using hardware circuits within it. It can also be configured so that various processes are performed by the cooperation of a processor such as an ASIP, memory, and hardware circuits within the wireless chip. ASIP stands for Application-specific instruction set processor.

[0014] The communication device 100 can communicate using radio signals in frequency bands such as the 2.4GHz, 3.6GHz, 5GHz, 6GHz bands, and millimeter wave bands such as the 45GHz and 60GHz bands. The frequency bands used by the communication device 100 are not limited to these, and may include, for example, the Sub1GHz band. Furthermore, the communication device 100 can communicate using bandwidths of 20MHz, 40MHz, 80MHz, 160MHz, 320MHz, 540MHz, 640MHz, 1080MHz, and 2160MHz. The bandwidths used by the communication device 100 are not limited to these, and may include, for example, 240MHz or 4MHz. Note that the IEEE 802.11 standard series specifies frequency channels using a 20MHz bandwidth as basic channels in frequency bands such as the 2.4GHz, 5GHz, and 6GHz bands. In addition, this standard defines multiple usable channels in each of the 2.4GHz, 5GHz, and 6GHz frequency bands. In this standard, the communication device 100 may use one channel in combination with other adjacent channels. This use of one channel in combination with other adjacent channels may be called channel bonding. A bundle of channels formed by one or two or more adjacent channels may be called a communication link. That is, one 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 bandwidth available for a single link. Signals transmitted in this bandwidth may be continuous or discontinuous on the frequency axis. AP101 and STA111 may be AP MLDs (Multi-Link Devices) and STA MLDs, respectively, that support Multi-Link, enabling communication by establishing multiple links simultaneously.

[0015] When the communication device 100 transmits a signal using a link established with another communication device, it performs carrier sensing to determine whether or not to transmit. Carrier sensing is the operation in which the communication device 100 determines whether or not there is a signal on the channel that it intends to use for transmission. For example, the communication device 100 measures the strength of the signal received on the channel (received signal strength) and determines that a signal exists if the received signal strength exceeds a predetermined threshold (physical carrier sensing). The received signal strength may also be called the Received Signal Strength Indicator (RSSI). The communication device 100 may also determine the presence or absence of a signal based on information such as the Duration field contained in the signal received on the channel (virtual carrier sensing). For example, the communication device 100 stores the period indicated by the Duration field contained in the received signal as a Network Allocation Vector (NAV) within itself. The communication device 100 can treat the stored NAV as a period during which it does not transmit. In this embodiment, the operation by which the communication device 100 sets a period during which it does not transmit based on information such as the Duration field of the received signal is called setting NAV. That is, until the NAV set for the channel expires, the communication device 100 determines that a signal is present on the channel. In this way, the communication device 100 determines whether or not a signal is present on the channel based on the results of performing physical carrier sensing and virtual carrier sensing. If the communication device 100 determines that a signal is present on the channel, it may determine that transmission is not possible. In this case, the 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 carrier sensing and NAV is not set may be called an idle state. If the channel is in an idle state, the communication device 100 may determine that transmission is possible.

[0016] The communication device 100 may, for example, determine whether transmission is possible using only the 20MHz bandwidth Primary Channel (PCH) included in a 160MHz bandwidth link when communicating. For example, the PCH is one of eight 20MHz bandwidth channels that make up the 160MHz bandwidth link. AP101 may notify STA110 of the PCH using a periodically broadcast Beacon frame. For example, the IEEE802.11 standard series states 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 over a predetermined period. The predetermined period is determined by the 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. Communication parameters including the IFS and random number range defined for each access category may be called EDCA parameters. EDCA is an abbreviation for Enhanced Distributed Channel Access. In other words, if the communication device 100 determines that the PCH is idle for this predetermined period, it acquires the right to transmit using that link. At this time, if channels other than the PCH were idle during the PIFS period immediately preceding the start of transmission, the communication device 100 may perform transmission by channel bonding using those idle channels and the PCH. PIFS is an abbreviation for Priority Interframe Space. Furthermore, if the communication device 100 determines that transmission is not possible as a result of carrier sensing on the PCH, it may postpone transmission even if other channels included in the same link are idle. Note that each channel other than the PCH that constitutes a single link may be called a secondary channel (SCH). A secondary channel may also be called a non-primary channel (NPCH).

[0017] In communication device 100, if a signal is being received on a certain channel, and another signal is being transmitted on a channel with a frequency close to that channel (for example, an adjacent channel), the received signal may not be properly received. For example, suppose communication device 100 can simultaneously perform transmission and reception using different channels. If communication device 100 is receiving on a certain channel and transmits on an adjacent channel, the power of the transmitted signal leaks into the channel of the received signal, causing interference to the received signal. Generally, the power due to such leakage of the transmitted signal is much greater than the received power of the received signal, so the received signal is not 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 that communication device is transmitting a signal. For example, a PCH is provided as a channel commonly used by communication devices to determine whether or not to transmit, and while one communication device is transmitting using the PCH, the other communication device is required not to transmit, even if other channels are idle. As a result, while a communication device is transmitting a signal and the PCH is in use, other communication devices will not transmit signals using channels adjacent to that PCH, thus preventing a situation where a communication device receives signals on those adjacent channels. This configuration eliminates the interference problem caused by power leakage between channels mentioned above.

[0018] However, as the IEEE 802.11 standard series has expanded, the bandwidth used in a single link has increased, and as described above, communication methods that always use a PCH may not be able to efficiently utilize frequency resources. For example, if other idle channels (NPCHs) are not used based on the PCH being busy, it can hinder the efficient use of frequency resources across the entire link. Figure 2(A) shows an example of a time chart when STA111 transmits data to AP101. In Figure 2(A), STA111 performs carrier sensing on the PCH, confirms that it is idle, and then transmits data using the 20MHz bandwidth PCH. In this case, for example, even if the seven NPCHs other than the PCH are idle, other communication devices are not allowed to communicate using the NPCHs. Figure 2(B) shows another example of a time chart when STA111 transmits data to AP101. In Figure 2(B), while STA111 is performing carrier sensing on the PCH, another network geographically close to STA111 (for example, network 122 in Figure 1) is using the PCH. In this case, STA111 determines that the PCH is busy during carrier sensing, so even if the other seven NPCHs are idle, for example, STA111 is not allowed to communicate with AP101 using the NPCHs. However, since AP101 is not transmitting at this time, even if STA111 were to transmit to AP101 using the NPCHs, AP101 could properly receive the signal transmitted by STA111. Thus, if, for example, a 20MHz bandwidth PCH is being used by another network, the remaining 140MHz of idle NPCHs cannot be utilized, resulting in inefficient use of frequency resources.

[0019] In contrast, if the PCH is being used by another communication device, the communication device 100 may, based on certain conditions, choose not to use the PCH and instead use an NPCH included in the same link as the PCH to communicate between communication devices. As an example, the communication device 100 sets up a Secondary Primary Channel (SPCH) to acquire the right to transmit using an NPCH when the PCH is busy. The SPCH is one or more channels among the NPCHs included in the same link as the PCH. Note that the SPCH may be called by other names, for example, a Primary Secondary Channel (PSCH). If the communication device 100 determines that the PCH is being used by a communication device in another network (OBSS), it then determines whether transmission is possible on the SPCH. If the communication device 100 determines that transmission is possible on the SPCH, it transmits using one or more NPCHs including the SPCH. In this embodiment, the communication method of transmitting using one or more channels including the SPCH without using the PCH is called NPCH access (Non-Primary Channel Access). NPCH access may be called NPCA. This communication method may also be called by other names. For example, this communication method may be called SCA (Secondary Channel Access). In this way, even when PCH is in use, the communication device 100 can communicate efficiently by using NPCH, which has little impact on PCH.

[0020] On the other hand, the IEEE 802.11ax standard specifies the SR function for the efficient use of frequency resources. SR is an abbreviation for Spatial Reuse. A communication device 100 that can use the SR function communicates using the same frequency as the OBSS by spatially separating itself from the communication taking place in the OBSS. For example, if the PCH is being used by another communication device, the communication device 100 may use this PCH to communicate based on certain conditions being met. The predetermined conditions may be that the PCH is being used by the OBSS and the received power from the OBSS to the communication device 100 is lower than a predetermined threshold. In this case, if the communication device 100 determines that the PCH is being used by the OBSS, it determines whether the received signal strength (RSSI) of the subsequently received signal is lower than a predetermined threshold. The predetermined threshold may be higher than the threshold used to determine whether the PCH is busy in normal carrier sensing. This allows the communication device to determine to use SR even if the PCH is determined to be busy in normal carrier sensing, based on the RSSI being lower than a predetermined threshold for determining the signal from the OBSS. Furthermore, when the communication device 100 performs communication using SR, it can mitigate interference to the OBSS by controlling its own transmission power based on the received power of the signal from the OBSS. The IEEE 802.11 standard series specifies two methods for transmission using SR: the OBSS PD method and the PSR method. OBSS PD is an abbreviation for OBSS Packet Detection. PSR is an abbreviation for Parameterized Spatial Reuse.

[0021] In the OBSS PD transmission method, the communication device 100 transmits while controlling the transmission power according to the received power of the signal received from OBSS, based on the fact that the received power of the signal received from OBSS is within a predetermined range. Figure 3(A) shows an example of the relationship between the received power of the signal received from OBSS and the transmission power used in transmission power control. The vertical axis of Figure 3(A) represents the value indicating the received power of the OBSS signal. The horizontal axis of Figure 3(A) represents the transmission power. For example, if the value indicating the received power of the OBSS signal is in the range of OBSS_PDmin to OBSS_PDmax, the communication device 100 transmits using a transmission power less than or equal to the TX_PWR value corresponding to that received power. Furthermore, if the value indicating the received power of the OBSS signal exceeds OBSS_PDmax, the communication device 100 does not transmit. In addition, if the value indicating the received power of the OBSS signal is OBSS_PDmin or less, the communication device 100 is not restricted in terms of transmission power. For example, the communication device 100 transmits using the transmission power in the area indicated by the shaded area in Figure 3(A). The OBSS PD transmission method can be used when the OBSS signal is a PPDU other than TB PPDU. TB is an abbreviation for Trigger Based.

[0022] Figure 3(B) shows the thresholds used in the OBSS PD method. As shown in Figure 3(B), the OBSS PD method may use different thresholds depending on the value of the Spatial Reuse Parameter Set IE, which will be described later. IE is an abbreviation for Information Element. For example, STA111 may set the maximum and minimum values ​​of OBSS PD based on the parameter values ​​included in the Spatial Reuse Parameter Set IE received from AP101. For example, STA111 may set the maximum and minimum values ​​of OBSS PD based on the value of Non-SRG OBSS PD SR Disallowed and the value of Non-SRG Offset present. The minimum value of OBSS PD may be called Non-SRG OBSS PDmin, and the maximum value of OBSS PD may be called Non-SRG OBSS PDmax.

[0023] For example, if STA111 does not receive a Spatial Reuse Parameter Set IE (element) from AP101, it may set the minimum value of OBSS PD to -82dBm and the maximum value of OBSS PD to -62dBm. Also, if both Non-SRG OBSS SR Disallowed and Non-SRG Offset Present are 0, STA111 may set the minimum and maximum values ​​of OBSS PD to -82dBm and -62dBm, respectively. Furthermore, if Non-SRG OBSS SR Disallowed is 0 and Non-SRG Offset Present is 1, STA111 may set the minimum value of OBSS PD to -82dBm. And the maximum value of OBSS PD may be set to -82dBm + Non-SRG OBSS PD max offset. Here, Non-SRG OBSS PD max offset is a predetermined value notified from AP101 to STA111. That is, AP101 can select a value for Non-SRG OBSS PD max offset from a predetermined range and notify its own BSS. Also, if the value of Non-SRG OBSS SR Disallowed is 1, STA111 can set the minimum and maximum values ​​of OBSS PD to -82dBm. In this case, it is indicated that the OBSS PD method of SR will not be used.

[0024] In a transmission method using the PSR method, the communication device 100 identifies the transmission power to be used for its own transmission based on the values ​​of communication parameters included in the received OBSS signal, and transmits using the identified transmission power. The transmission method using the PSR method can be used when the signal received from OBSS is a Trigger frame or a TB PPDU. For example, the communication device 100 can identify the transmission power to be used for PSR transmission based on the values ​​of parameters related to SR included in the SIG of the physical layer (PHY) header included in the received Trigger frame or TB PPDU. Figure 4 shows an example in which AP101 transmits a PPDU using the PSR method based on a Trigger frame and HE TB PPDU exchanged between AP102 and STA112, which constitute the OBSS. First, AP102 acquires the right to transmit on the PCH and transmits a Trigger frame 401. This Trigger frame may be called a PSPR. PSPR is an abbreviation for Parameterized Spatial Reuse Reception. This Trigger frame 401 may contain a Common Info field 402 and one or more User Info fields 403. The Common Info field 402 may contain four 4-bit Uplink Spatial Reuse fields. Figure 5(A) shows the correspondence between the values ​​of the Uplink Spatial Reuse field in the Trigger frame and what those values ​​indicate. For example, a value of 0 in the Uplink Spatial Reuse field indicates that PSR transmission is prohibited. A value of 15 in the Uplink Spatial Reuse field indicates that both PSR transmission and OBSS PD transmission are prohibited. Also, if the value of the Uplink Spatial Reuse field is any of 1 to 14, the corresponding transmission power may be indicated as the transmission power that the communication device 100 should use. The Common Info field 402 may contain a UL Length field. The UL Length field may indicate the length of the TB PPDU following this Trigger frame.The User Info field may contain information about the resources assigned to STA112.

[0025] When STA112 receives Trigger frame 401, it transmits HE TB PPDU 404. HE is an abbreviation for High Efficiency. HE TB PPDU 404 may include a Spatial Reuse field. The correspondence between the value of the Spatial Reuse field in HE TB PPDU 404 and the content that the value represents is the same as in Figure 5(A). For example, STA112 may generate HE TB PPDU 404 that includes the value of the Uplink Spatial Reuse field contained in the received Trigger frame in the Spatial Reuse field. The structure of HE TB PPDU 404 will be described later. When AP102 successfully receives HE TB PPDU, it transmits BA 406 to indicate that the reception was successful. BA is an abbreviation for Block Acknowledgement. Figure 5(B) shows the correspondence between the value of the Spatial Reuse field and the content that the value represents in PPDUs other than TB PPDU. For example, similar to TB PPDU, a value of 0 in the Spatial Reuse field indicates that PSR transmission is prohibited. A value of 15 in the Spatial Reuse field indicates that both PSR and OBSS PD transmission are prohibited.

[0026] AP101 receives Trigger frame 401 and the subsequent HE TB PPDU 404. Based on the value of the Spatial Reuse field contained in HE TB PPDU 404, AP101 determines the transmit power that should be used for its own transmission. Then, AP101 transmits PPDU 407 using the determined transmit power. This PPDU may be called a PSRT PPDU. PSRT may be an abbreviation for Parameterized Spatial Reuse Transmission. Upon receiving PSRT PPDU 407, STA111 transmits BA408. The frame lengths of PSRT PPDU 407 and BA408 may be determined so that the exchange of PSRT PPDU 407 and BA408 is completed before the transmission of HE TB PPDU 404 is finished.

[0027] A communication device 100 compliant with the IEEE 802.11bn standard may be configured to perform multiple communication methods for efficient use of frequency resources. In this case, the communication device 100 can perform communication by selectively using each of the multiple communication methods. For example, the communication device 100 can perform communication by selectively using SR communication and NPCA communication depending on the channel usage status. Here, if the transmitting communication device and the receiving communication device select different transmission methods for receiving signals from the same OBSS, communication may fail. For example, the SR communication method is a communication method that uses the PCH. In contrast, the NPCA communication method is a communication method that does not use the PCH and uses a channel different from the PCH. Therefore, if one communication device selects the NPCA communication method and the other communication device selects the SR communication method, the channels on which they operate will be different. In this way, if the transmitting communication device and the receiving communication device operate on different channels due to the difference in the communication methods they have selected, the signal transmitted by the transmitting communication device may not be properly received by the receiving communication device.

[0028] In light of these circumstances, the AP in this embodiment notifies reference information to determine whether to select a communication method using SR or a communication method using NPCA when a wireless frame transmitted in OBSS is detected in PCH. For example, AP101 communicates using a first communication method configured to enable communication by bonding a first channel with a second channel different from the first channel. The first communication method is a communication method that communicates on the first channel without using the Spatial Reuse function based on the fact that a wireless frame transmitted in OBSS is not detected in the first channel. The first channel and the second channel are PCH and NPCH, respectively. In addition, in the first communication method, only PCH may be used and NPCH may not be used. Furthermore, AP101 communicates using a second communication method that communicates on the first channel using the Spatial Reuse function based on the fact that a wireless frame transmitted in OBSS is detected in the first channel. Furthermore, AP101 communicates using a third communication method that uses the second channel instead of the first channel, based on the detection of a wireless frame transmitted in OBSS on the first channel. When AP101 detects a wireless frame transmitted in OBSS on the first channel, it determines the communication method to use based on reference information and communicates. In addition, the STA in this embodiment acquires reference information to determine whether to select a communication method using SR or a communication method using NPCA when a wireless frame transmitted in OBSS is detected on the PCH. For example, STA111 communicates with AP101 using multiple communication methods, including the first, second, and third communication methods. When STA111 detects a wireless frame transmitted in OBSS on the first channel, it determines the communication method to use based on reference information and communicates. With this configuration, when AP101 and STA111 detect a wireless frame transmitted in OBSS on the first channel, they determine the communication method to use based on the same reference information and communicate.This allows AP101 and STA111 to operate on the same channel, reducing the possibility of communication failures caused by each communication device operating on different channels.

[0029] For example, the reference information may include information indicating that the second communication method should be given priority. For example, the reference information may include information indicating that the third communication method should be given priority. For example, the reference information may include information indicating the priority assigned to the second communication method and the priority assigned to the third communication method. In this way, by notifying AP101 and STA111 of information indicating which of the second and third communication methods should be given priority as reference information, AP101 and STA111 will prioritize selecting the same communication method. The reference information may also include information indicating predetermined conditions under which the second communication method should not be selected. For example, the predetermined conditions may be satisfied by including information in the radio frame received from OBSS indicating that communication using the second communication method is prohibited. Alternatively, the predetermined conditions may be satisfied by receiving a radio frame containing identification information that identifies it as a radio frame transmitted by OBSS when a request to prohibit communication using the second communication method is received from an AP constituting OBSS. The reference information may also include information indicating predetermined conditions under which the third communication method should not be selected. For example, a predetermined condition may be met if the frequency band used by the radio frame transmitted in OBSS overlaps with a portion of the frequency band corresponding to the second channel. Alternatively, a predetermined condition may be met if the time the first channel is used for communication of the radio frame transmitted in OBSS is less than a predetermined threshold. In this way, when a predetermined condition is met, information indicating that either the second or third communication method is prohibited is notified, causing AP101 and STA111 to choose and execute the other communication method instead of the first one. An example configuration and processing example of a communication device 100 operating in this manner is described below.

[0030] (Device configuration) Figure 6 shows an example of the hardware configuration of the communication device 100 in this embodiment. As an example of its hardware configuration, the communication device 100 includes, for example, a storage unit 601, a control unit 602, a function unit 603, an input unit 604, an output unit 605, a communication unit 606, and an antenna 607. The communication device 100 may have multiple antennas.

[0031] The storage unit 601 is composed of one or more memories, including ROM and RAM, and may store control programs for various operations of each functional unit constituting the communication device 100, as well as various information such as parameters for communication. ROM and RAM are abbreviations for Read Only Memory and Random Access Memory, respectively. In addition to memories such as ROM and RAM, the storage unit 601 may also be composed of storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs.

[0032] The control unit 602 is composed of one or more processors, such as a CPU and an MPU, and controls the entire communication device 100 by executing a control program stored in the memory unit 601. Alternatively, the control unit 602 may control the entire communication device 100 in cooperation with the OS (Operating System) and the control program stored in the memory unit 601. CPU and MPU are abbreviations for Central Processing Unit and Micro Processing Unit, respectively. If the control unit 602 has multiple processors, such as a multi-core processor, it may be configured so that the entire communication device 100 is controlled by multiple processors.

[0033] Furthermore, the control unit 602 controls the functional unit 603 to perform predetermined processes such as communication, imaging, printing, and projection. The functional unit 603 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 603 is the imaging unit and performs imaging processing. Also, for example, if the device is a printer, the functional unit 603 is the printing unit and performs printing processing. Also, for example, if the device is a projector, the functional unit 603 is the projection unit and performs projection processing.

[0034] The input unit 604 receives various operations from the user. The output unit 605 outputs various information to the user via a monitor screen or speaker. The output from the output unit 605 may be a display on the monitor screen, audio output via a speaker, vibration output, etc. The input unit 604 and the output unit 605 may both be implemented in a single module, such as a touch panel. The input unit 604 and the output unit 605 may each be an integrated device with the communication device 100, or they may be separate devices.

[0035] The communication unit 606 controls wireless communication compliant with the IEEE 802.11bn standard. In addition to the IEEE 802.11bn standard, the communication unit 606 may also control wireless communication compliant with other IEEE 802.11 standard series, such as legacy standards. The communication unit 606 controls the antenna 607 to transmit and receive signals for wireless communication generated by the control unit 602. The communication unit 606 is a so-called wireless chip and may itself include one or more processors and memory. If the communication device 100 supports other wireless communication standards such as NFC and Bluetooth, or wired communication such as wired LAN, in addition to the IEEE 802.11bn standard, the communication unit 606 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 have separate communication units and antennas corresponding to each communication standard. The communication device 100 communicates data with the other communication device via the communication unit 606. The antenna 607 may be configured separately from the communication unit 606, or it may be configured as a single module together with the communication unit 606. If the communication device 100 is configured to perform carrier sensing of multiple SPCHs simultaneously, the communication device 100 may be provided with the necessary number of communication units 606 for that purpose.

[0036] Antenna 607 is an antenna capable of communication in the 2.4GHz band, 5GHz band, 6GHz band, and millimeter wave bands such as 45GHz and 60GHz. Figure 6 shows a configuration in which the communication device 100 has two antennas 607, but the communication device 100 may have one or more antennas, and may have one or more antennas for each frequency band that the device can use. Also, if the communication device 100 has multiple antennas, the communication device 100 may have a communication unit 606 for each antenna. Antenna 607 may be physically composed of two or more antennas in order to realize (Multi-Input and Multi-Output) transmission and reception.

[0037] (Functional Configuration) Figure 7 shows an example of the functional configuration of AP101. The functional configuration in this embodiment is an example of a functional configuration realized by, for example, one or more processors executing programs stored in one or more memories. AP101 may be configured to include a wireless communication control unit 701, an information notification unit 702, a received frame analysis unit 703, a communication method selection unit 704, and an AP-to-AP communication execution unit 705.

[0038] The wireless communication control unit 701 performs wireless communication using the communication method selected by the communication method selection unit 704. For example, if the first communication method is selected by the communication method selection unit 704, the wireless communication control unit 701 transmits or receives wireless frames using the PCH. If the second communication method is selected by the communication method selection unit 704, the wireless communication control unit 701 transmits or receives wireless frames using the PCH with a communication method that uses Spatial Reuse. Furthermore, if the third communication method is selected by the communication method selection unit 704, the wireless communication control unit 701 transmits or receives wireless frames using the PCH.

[0039] The information notification unit 702 notifies reference information used to determine whether to select the second communication method or the third communication method when a wireless frame transmitted in another BSS is detected in the PCH. For example, the information notification unit 702 notifies reference information using a Beacon frame.

[0040] The received frame analysis unit 703 analyzes the received wireless frame. For example, the received frame analysis unit 703 identifies the frame format based on the type of wireless frame for the wireless frame received by the wireless communication control unit 701, and acquires the information contained in the wireless frame according to the identified frame format. The received frame analysis unit 703 can also perform various determinations based on the acquired information. For example, the received frame analysis unit 703 can determine the BSS to which the received frame was transmitted, and whether or not communication using SR is prohibited in the received frame. The received frame analysis unit 703 can also determine the frequency band used by the received frame, and the period during which the PCH is used based on the received frame.

[0041] The communication method selection unit 704 determines the communication method that the device should use. For example, the communication method selection unit 704 may determine the communication method that the wireless communication control unit 701 should use based on the determination result of the received frame analysis unit 703. For example, the communication method selection unit 704 may decide not to use SR communication if the received frame is a wireless frame transmitted by a specific OBSS. Also, the communication method selection unit 704 may decide not to use SR communication if the received frame contains information indicating that SR communication is prohibited. In these cases, the communication method selection unit 704 may determine whether or not NPCA communication is possible and determine the communication method to be used based on the result. On the other hand, the communication method selection unit 704 may decide not to use NPCA communication if the frequency band used by the received frame partially overlaps with the frequency band corresponding to the NPCA used when using NPCA. Furthermore, the communication method selection unit 704 may decide not to use NPCA communication if the time the PCH is used by the received frame is less than a predetermined threshold. In these cases, the communication method selection unit 704 may determine whether or not it is possible to use SR communication and decide which communication method to use based on the result. If any communication method is available, the communication method selection unit 704 may decide which communication method to use is the one shared between AP101 and STA111 as the preferred communication method.

[0042] The AP-to-AP communication execution unit 705 communicates with other APs. For example, the AP-to-AP communication execution unit 705 can execute procedures for coordinating communication with other APs. As an example, the AP communication execution unit 705 may receive a request from another AP to prohibit communication using SR. The AP communication execution unit 705 may also send a request to another AP to prohibit communication using SR.

[0043] AP101, as an AP constituting an OBSS, may have a functional unit for communicating with STAs participating in that OBSS. For example, AP101 may have an SR control unit 706. The SR control unit 706 can perform control for SR within its own BSS. For example, the SR control unit 706 can determine whether or not to prohibit communication using SR in other BSSs while a radio frame is being transmitted in its own BSS. If it is determined that communication using SR in other BSSs should be prohibited while a radio frame is being transmitted in its own BSS, the SR control unit 706 can perform control to prohibit communication using SR in other BSSs. For example, the SR control unit 706 can instruct STAs participating in its own BSS to include information indicating that communication using SR is prohibited in the PPDU it transmits. The SR control unit 706 can also send a request to other APs via the inter-AP communication execution unit 705 to prohibit communication using SR.

[0044] Figure 8 shows an example of the functional configuration of STA111. 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. STA111 may be configured to include a wireless communication control unit 801, an information acquisition unit 802, a received frame analysis unit 803, a communication method selection unit 804, and an SR control unit 805. The operation of the wireless communication control unit 801, the received frame analysis unit 803, and the communication method selection unit 804 is the same as that of the wireless communication control unit 701, the received frame analysis unit 703, and the communication method selection unit 704, respectively. The information acquisition unit 802 acquires reference information used to determine whether to select a second communication method or the third communication method when a wireless frame transmitted in another BSS is detected in the PCH. For example, the information acquisition unit 802 may receive a Beacon frame and acquire reference information contained in the received Beacon frame. The SR control unit 805 may receive instructions from APs that constitute the BSS in which its device participates, indicating that the PPDU to be transmitted should include information indicating that communication using SR is prohibited. Based on these instructions, the SR control unit 805 may control the PPDU transmitted by the wireless communication control unit 801 to include information indicating that communication using SR is prohibited.

[0045] (Process flow) The following describes an example of the processing flow performed by AP101 and STA111 in this embodiment. First, an overview of the communication performed between AP101 and STA111 will be explained using Figure 9. Figure 9 shows an example of the message sequence exchanged between AP101 and STA111 in Figure 1. In addition to the wireless frames communicated between AP101 and STA111, Figure 9 also shows wireless frames communicated between AP102 and STA112 as wireless frames communicated in OBSS. This sequence may start, for example, when the power to STA111 is turned on and STA111 starts up. First, STA111 starts connecting to AP101. For example, AP101 may periodically transmit Beacon frames (F901). The Beacon frame may include the BSS identifier provided by AP101 (e.g., BSSID), AP101 capability information, and communication parameters that can be used for communication with AP101. BSSID is an abbreviation for BSS Identifier. When STA111 detects the presence of AP101 by receiving a Beacon frame transmitted by AP101, it may initiate the connection procedure to AP101. For example, as part of the connection procedure to AP101, STA111 first sends a Probe Request frame (F902). AP101 responds to the Probe Request frame by sending a Probe Response frame (F903). Subsequently, AP101 and STA111 perform authentication of each other's communication devices by exchanging Authentication frames (F904). Once authentication is complete, STA111 sends an Association Request frame to AP101 (F905). AP101 responds to the Association Request frame by sending an Association Response frame (F906). Through this connection procedure, a connection is established between AP101 and STA111. Note that the connection procedure between AP101 and STA111 is not limited to the above, and may include other steps, or some steps may be omitted.For example, after AP101 sends an Association Response frame, a 4-Way handshake may be performed to exchange security information.

[0046] During this connection procedure, STA111 may notify AP101 of its capabilities. For example, STA111 may notify AP101 of information indicating that it has the capability to perform communication using SR or NPCA, and information indicating the time required to switch between PCH operation and NPCH operation (channel switch delay time). STA111's capabilities may be notified using, for example, Probe Request frames or Association Request frames. Similarly, AP101 may notify STA111 of its capabilities during this connection procedure. For example, AP101 may notify STA111 of information indicating that it has the capability to perform communication using SR or NPCA, and channel switch delay time. AP101's capabilities may be notified using, for example, Beacon frames, Probe Response frames, or Association Response frames. AP101 and STA111 can mutually recognize that they are capable of performing communication using NPCA by sharing their respective capability information with the other party's communication device. When AP101 and STA111 reconnect (reassociate), capability information of their respective communication devices may be exchanged using Reassociation Request frames and Reassociation Response frames. In addition, AP101 and STA111 may set the communication parameters to be used when performing NPCA after the connection procedure described above. The communication parameters to be used when performing NPCA may include information to identify the SPCH, information to identify the NPCH to be used for NPCA and the frequency band corresponding to the NPCH, and the TXOP threshold for performing NPCA.

[0047] STA111 obtains reference information from AP101 to determine whether to use SR or NPCA for communication (F907). For example, the reference information may be included in the Beacon frame transmitted by AP101. In this case, STA111 can determine whether to use SR or NPCA based on the reference information included in the Beacon frame. Note that STA111 can obtain the reference information by means other than receiving the Beacon frame. For example, STA111 can obtain the reference information during the connection procedure when establishing a connection with AP101. Note that STA111 can obtain the reference information using frames received after establishing a connection with AP101, such as Action frames. This enables dynamic changes between AP101 and STA111 regarding whether to use SR or NPCA for communication.

[0048] Once a connection is established between AP101 and STA111, data communication primarily uses a communication method that utilizes the PCH. For example, if the PCH is idle, STA111 will send data (PPDU) using the PCH (F908). AP101 will then send a BA in response to the received data (PPDU) using the PCH (F909).

[0049] On the other hand, AP101 and STA111 can receive signals from OBSS. For example, when data is transmitted from STA112 to AP102 (F910), this data can be received by AP101 and STA111. Figure 9 shows that data transmitted from STA112 is received by AP101, AP102, and STA111 (F910). This sets TXOP on the PCH (F911). When AP101 and STA111 each receive a signal from STA112, they determine the action they should take during the set TXOP period based on the received signal. For example, AP101 and STA111 each determine whether they should operate on the PCH to perform communication using SR, or switch to the NPCH to perform communication using NPCA. As an example, STA111 may determine which communication method to use based on reference information obtained from AP101. AP101 can determine which communication method to use based on the reference information it has notified STA111 of. Since AP101 and STA111 use the same criteria and information to determine which communication method to use, the determination results of AP101 and STA111 will be the same. For example, STA111 may determine that it should perform communication using SR and transmit data using SR on the PCH (F912). At this time, AP101 may also determine that it should perform communication using SR, similar to STA111, and perform a receiving operation on the PCH. If AP101 successfully receives the data transmitted by STA111, it may transmit BA using SR on the PCH (F913).

[0050] On the other hand, AP101 and STA111 can receive data transmitted from AP102. For example, when data is transmitted from AP102 to STA112 (F914), this data can be received by AP101 and STA111. Figure 9 shows that data transmitted from AP102 is received by AP101, STA111, and STA112 (F914). As a result, TXOP is set on the PCH (F915). AP101 and STA111 each determine whether to perform communication using SR or NPCA, similar to the case of F911. For example, STA111 determines that it should perform communication using NPCA, switches the operating channel to NPCH, and transmits data (F916). At this time, AP101, similar to STA111, determines that it should perform communication using NPCA, switches the operating channel to NPCH, and performs the receiving operation. When AP101 successfully receives data transmitted by STA111, it transmits a BA (F917) on NPCH.

[0051] In this embodiment, AP101 notifies STA111 of reference information used to determine whether to select a communication method using SR or a communication method using NPCA. STA111 also receives reference information from AP101 to determine whether to select a communication method using SR or NPCA. Upon receiving a signal from OBSS, AP101 and STA111 then decide which communication method to execute based on this reference information. With this configuration, AP101 and STA111 use the same criteria and information to determine which communication method to execute, resulting in each device executing the same communication method.

[0052] Furthermore, if the conditions for prioritizing either SR-based communication or NPCA-based communication are predetermined by standards, etc., STA111 may select either communication method without obtaining reference information from AP101. For example, if the signal received from OBSS contains information indicating that SR-based communication is prohibited, it may be predetermined that NPCA-based communication should be performed instead of SR-based communication. In this case, STA111 may select NPCA-based communication based on the fact that the signal received from OBSS contains information indicating that SR-based communication is prohibited, without obtaining reference information from AP101.

[0053] (Process for determining the communication method) Figure 10 shows an example of a processing flow used when AP101 and STA111 decide whether to perform communication using SR or NPCA. This processing flow can be performed by each communication device 100 based on the reception of a signal from OBSS on the PCH. Hereinafter, signals from OBSS may be referred to as OBSS frames. Communication device 100 determines whether the frame received on the PCH is a frame of its own BSS or an OBSS frame (S1001). If the received frame is a frame of its own BSS (NO in S1001), communication device 100 continues operation on the PCH and waits until the PCH becomes free (S1012). If the frame received on the PCH is a frame destined for the communication device 100, it performs reception processing on that frame.

[0054] If the frame received by the PCH is an OBSS frame (YES in S1001), the communication device 100 determines whether to perform communication using SR or communication using NPCA. The communication device 100 determines which of the two communication methods to prioritize (S1002). For example, the communication device 100 may determine which of the two communication methods to prioritize based on reference information. If the communication device 100 determines that communication using SR should be prioritized over communication using NPCA (YES in S1002), it determines whether it is possible to perform communication using SR (S1003). If it is possible to perform communication using SR (YES in S1003), the communication device 100 decides to perform communication using SR (S1004). On the other hand, if it is not possible to perform communication using SR (NO in S1003), the communication device 100 determines whether it is possible to perform communication using NPCA (S1005). If communication using NPCA is possible (YES in S1005), the communication device 100 decides to perform communication using NPCA (S1006). If communication using NPCA is not possible (NO in S1005), the communication device 100 continues to operate on the PCH and waits until the PCH becomes available (S1007).

[0055] On the other hand, if the communication device 100 determines that communication using NPCA should be prioritized over communication using SR (NO in S1002), it determines whether or not it is possible to perform communication using NPCA (S1008). If it is possible to perform communication using NPCA (YES in S1008), the communication device 100 decides to perform communication using NPCA (S1009). On the other hand, if it is not possible to perform communication using NPCA (NO in S1008), the communication device 100 determines whether or not it is possible to perform communication using SR (S1010). If it is possible to perform communication using SR (YES in S1010), the communication device 100 decides to perform communication using SR (S1011). If it is not possible to perform communication using SR (NO in S1010), the communication device 100 continues to operate on the PCH and waits until the PCH becomes available (S1007).

[0056] (Priority given to communication methods using SR based on reference information versus communication methods using NPCA) As described above, the communication device 100 can determine which communication, using SR or using NPCA, should be prioritized based on reference information notified from AP101 to STA111 (S1002). For example, the reference information may be information indicating that communication using SR should be prioritized. Alternatively, the reference information may be information indicating that communication using NPCA should be prioritized. In these cases, AP101 can notify STA111 of information indicating the preferred communication method. For example, AP101 can notify STA111 of a wireless frame containing an information element that includes a field indicating the preferred communication method. As an example, if the value of the field indicating the preferred communication method is set to 0, it may indicate that communication using SR should be prioritized. Alternatively, if the value of the field indicating the preferred communication method is set to 1, it may indicate that communication using NPCA should be prioritized. Furthermore, the reference information may also be information indicating the priority of communication using SR and communication using NPCA, respectively. In this case, AP101 may notify STA111 of a radio frame containing an information element that includes a field indicating the priority assigned to communication using SR and a field indicating the priority assigned to communication using NPCA. The reference information may also be information indicating predetermined conditions under which communication using SR should not be performed. For example, if AP101 is requested by an AP constituting the OBSS to prohibit communication using SR, AP101 may notify STA111 of information to identify that BSS. The information to identify the BSS may be the BSS Color or BSSID. In this case, AP101 may notify STA111 of a radio frame containing an information element that includes a field indicating identification information for identifying the BSS. STA111 may refrain from performing communication using SR while receiving an OBSS frame containing the identification information indicated by this field.Furthermore, AP101 may notify STA111 that communication using SR should not be performed if the OBSS frame contains information indicating that communication using SR should not be performed. In this case, AP101 may notify STA111 of a wireless frame containing an information element with a field set to 1 indicating that communication using SR should not be performed if the OBSS frame contains information indicating that communication using SR should not be performed. On the other hand, reference information may be information indicating predetermined conditions under which communication using NPCA should not be performed. For example, the predetermined condition may be that the frequency band used by the OBSS frame overlaps with a portion of the frequency band corresponding to the NPCH used by NPCA. In this case, AP101 may notify STA111 of a wireless frame containing an information element with a field set to 1 indicating that communication using NPCA should not be performed if the bandwidth of the OBSS frame overlaps with a portion of the bandwidth corresponding to the NPCH used by NPCA. Alternatively, the predetermined condition may be that the time for which the PCH is used by the OBSS frame communication is less than a predetermined threshold. In this case, AP101 may notify STA111 of a wireless frame containing an information element with a field indicating a predetermined threshold. STA111 may determine that communication using NPCA is prohibited if the TXOP set on the PCH by the OBSS frame is smaller than a predetermined threshold. TXOP is an abbreviation for Transmission Opportunity. This reference information may be used to determine the priority between communication using SR and communication using NPCA in S1002 of Figure 10, or it may be used in other determination processes. Furthermore, this reference information may be used in combination. For example, in S1002 of Figure 10, the reference information may indicate that communication using SR should be prioritized, or that communication using NPCA should be prioritized, and other reference information may be used in subsequent determination processes. As an example, in S1003 and S1010, reference information indicating predetermined conditions under which communication using SR should not be performed may be used. Also, in S1005 and S1008, reference information indicating predetermined conditions under which communication using NPCA should not be performed may be used.

[0057] (Process for determining whether or not to execute a communication method using SR) Figure 11 shows an example of a processing flow used by AP101 and STA111 to determine whether or not a communication method using SR is possible. This processing flow corresponds, for example, to the determination processes executed in S1003 and S1010 in Figure 10. As an example, communication device 100 may determine whether or not a communication method using SR is possible based on whether or not communication using SR is prohibited while the received OBSS frame is being communicated. For example, communication device 100 may determine that communication using SR is prohibited while the received OBSS frame is being communicated based on the fact that a coordination procedure including prohibiting communication using SR has been executed in advance between AP101 and AP102. Alternatively, communication device 100 may determine that communication using SR is prohibited while the received OBSS frame is being communicated based on information indicated in a predetermined field contained in the received frame. The methods by which communication device 100 determines whether or not communication using SR is prohibited while the received OBSS frame is being communicated are not limited to these, but Figure 11 explains using an example of determining whether or not communication using SR is possible based on these methods.

[0058] AP101 determines whether a coordination procedure, including prohibiting communication using SR, has been executed in advance between AP101 and AP102 (S1101). For example, if AP101 has executed a coordination procedure with AP102, it may make a determination based on whether the coordination procedure includes a request to prohibit SR from AP102. If AP101 is executing a coordination procedure with AP102 (YES in S1101), it determines whether the coordination procedure includes a request to prohibit communication using SR from AP102 (S1102). If the request to prohibit communication using SR is included (YES in S1102), AP101 may determine that it cannot execute communication using SR when it receives a frame from OBSS configured by AP102 (S1105). The coordination procedure between AP101 and AP102 may be called a Multi-AP (MAP) coordination procedure. In the MAP coordination procedure, information exchange and negotiation can be performed among multiple APs to coordinate the allocation of OFDMA resources, roaming, and other operations. For example, in this embodiment, the MAP coordination procedure can involve negotiation between AP101 and AP102 to not perform communication using SR.

[0059] On the other hand, STA111 can obtain information from AP101 indicating whether a coordination procedure, including prohibiting communication using SR, has been executed in advance between AP101 and AP102. For example, if the Beacon frame transmitted by AP101 contains information regarding the MAP coordination procedure, STA111 can obtain information regarding the MAP coordination procedure between AP101 and AP102 by receiving this Beacon frame. If AP101 is executing a coordination procedure with AP102 (YES in S1101), STA111 determines whether that coordination procedure includes a request from AP102 to prohibit communication using SR (S1102). If the request to prohibit communication using SR is included (YES in S1102), STA111 can determine that communication using SR cannot be performed when it receives a frame from OBSS configured by AP102 (S1105).

[0060] Furthermore, if AP101 is not performing the MAP coordination procedure with AP102 (NO in S1101), AP101 and STA111 determine whether to perform communication using SR based on the received OBSS frame (S1103). Similarly, if the MAP coordination procedure does not include a request to prohibit the performance of communication using SR (NO in S1102), AP101 and STA111 determine whether to perform communication using SR based on the received OBSS frame (S1103). The communication device 100 may make a determination based, for example, on whether the Uplink Spatial Reuse field of the received OBSS Trigger frame indicates that PSR transmission or OBSS PD transmission is prohibited. The communication device 100 may also make a determination based, for example, on whether the Spatial Reuse field of the received OBSS TB PPDU frame indicates that PSR transmission or OBSS PD transmission is prohibited. If the received OBSS frame contains information indicating that communication using SR is prohibited (YES in S1103), the communication device 100 may determine that communication using SR cannot be performed (S1105). Conversely, if the received OBSS frame does not contain information indicating that communication using SR is prohibited (NO in S1103), the communication device 100 may determine that communication using SR is possible (S1104).

[0061] (Determination process for whether or not to execute a communication method using NPCA) Figure 12 shows an example of a processing flow used when AP101 and STA111 determine whether or not they can perform a communication method using NPCA. This processing flow corresponds to the determination processes performed in S1005 and S1008 in Figure 10, for example. As an example, communication device 100 may determine whether or not it can perform communication using NPCA based on whether or not it has the frequency resources and time resources to perform communication using NPCA while the received OBSS frame is being communicated. First, communication device 100 determines whether or not it has the frequency resources to perform communication using NPCA (S1201). For example, communication device 100 determines whether or not the bandwidth of the received OBSS frame overlaps with the NPCH that it uses when performing NPCA. As an example, STA111 may determine the communication parameters to be used when performing NPCA when exchanging capability information regarding NPCA in the connection procedure with AP101. For example, STA111 may determine that AP101 is the SPCH and NPCH to be used when performing NPCA. Furthermore, AP101 and STA111 may determine that communication using NPCA cannot be performed if a portion of the OBSS frame overlaps with the NPCH determined with the other party's communication device on the frequency axis (YES in S1201) (S1204).

[0062] Furthermore, if the OBSS frame does not overlap with the NPCH determined with the other communication device on the frequency axis (NO in S1201), the communication device 100 determines whether there are time resources available to perform communication using NPCA (S1202). For example, if the length of the TXOP set by the OBSS frame is greater than or equal to a predetermined value (YES in S1202), the communication device 100 determines that communication using NPCA is possible (S1203). On the other hand, if the length of the TXOP set by the OBSS frame is less than a predetermined value (NO in S1202), the communication device 100 determines that communication using NPCA is not possible (S1204). For example, the communication device 100 can set a predetermined value that includes the time required to communicate the data to be transmitted using NPCA and the channel switch delay time for switching between operation on the PCH and operation on the NPCH. This allows the communication device 100 to determine whether or not to perform communication using NPCA after securing time for data communication and time for switching operations. Furthermore, the communication device 100 may use methods other than those described above to determine whether or not a communication method using NPCA is feasible.

[0063] (Analysis of received frames) The communication device 100 determines whether or not to perform communication using SR or NPCA based on the information contained in the received OBSS frame. Examples of information that can be used for these determinations are described below. Figures 13(A) to 13(D) show examples of PPDU frame formats specified in the IEEE 802.11 standard series. Figure 14 shows an example of a processing flow when acquiring information contained in a frame according to the frame format corresponding to the PPDU type of the received frame, and determining whether or not to perform communication using SR or NPCA based on the acquired information.

[0064] Figures 13(A) and 13(B) show examples of HE PPDU formats as defined in the IEEE 802.11ax standard. Figure 13(A) shows an example of the HE TB PPDU format. In addition to HE TB PPDU, the IEEE 802.11ax standard defines three other PPDU types: HE SU PPDU, HE ER PPDU, HE MU PPDU, and HE TB PPDU. SU is an abbreviation for Single-user. ER is an abbreviation for Extended-range. MU is an abbreviation for Multi-user. Figure 13(B) shows an example of the format common to the three HE PPDU types other than HE TB PPDU.

[0065] The HE PPDUs shown in Figures 13(A) and 13(B) may consist of L-STF1601, L-LTF1602, L-SIG1603, RL-SIG1604, HE-SIG-A1605, Data1606, and PE1607, respectively. L-STF is an abbreviation for Legacy-Short Training Field. L-LTF is an abbreviation for Legacy-Long Training Field. L-SIG is an abbreviation for Legacy-Signal Field. RL-SIG is an abbreviation for Repeated L-SIG. PE is an abbreviation for Packet Extension. The HE TB PPDU and the other three HE PPDUs differ in the number of Spatial Reuse fields included in HE-SIG-A1605 and 1609, respectively. Furthermore, fields L-STF1601 to RL-SIG1604 are common to all four HE PPDU formats. Fields HE-SIG-A1605 and later, and HE-SIG-A1609 and later, differ depending on the format, but the Spatial Reuse field is present in all formats. In addition, HE-SIG-A1605 and 1609 each include the BSS Color field, Bandwidth field, and TXOP field. The BSS Color field identifies the BSS to which the communication device that transmitted the PPDU is participating. The Bandwidth field indicates the bandwidth of the PPDU. The TXOP field indicates the length of time that the received frame occupies the channel.

[0066] The process of determining whether communication using SR or NPCA is possible based on the information contained in the HE PPDU described above will be explained using Figure 14. First, the communication device 100 identifies the format of the PPDU of the received frame (S1401, S1402). For example, in the case of an HE PPDU, it can be identified as an HE PPDU by the presence of RL-SIG1604 in the PHY header (HE in S1402). The communication device 100 determines whether it is a local BSS frame or an OBSS frame based on the value of the BSS Color field contained in HE-SIG-A1605 or 1609 (S1433). For example, if the BSS Color contained in the received frame matches the BSS Color of the local BSS, the communication device 100 determines that it is a local BSS frame. Also, if the BSS Color contained in the received frame does not match the BSS Color of the local BSS, the communication device 100 determines that it is an OBSS frame. The communication device 100 uses the Bandwidth field included in HE-SIG-A1605 or 1609 to determine whether a portion of the received frame overlaps with the NPCH used by the device on the frequency axis (S1434). For example, the communication device 100 may determine whether a portion of the frequency band specified by the Bandwidth field included in the received frame overlaps with the NPCH used by the device in NPCA. The communication device 100 uses the TXOP field included in HE-SIG-A1605 or 1609 to determine whether the TXOP of the received frame is greater than or equal to a predetermined value (S1435). Then, the communication device 100 uses the Spatial Reuse field included in HE-SIG-A1605 or 1609 to determine whether communication using SR is prohibited (S1436). The communication device 100 may also use other fields included in HE PPDU to determine whether communication using SR or communication using NPCA is permitted.

[0067] Figures 13(C) and 13(D) show examples of the EHT PPDU format specified in the IEEE 802.11be standard. EHT is an abbreviation for Extremely High Throughput. Note that the formats shown in Figures 13(C) and 13(D) can also be used in successor standards to the IEEE 802.11be standard (e.g., the IEEE 802.11bn standard). PPDUs specified in the IEEE 802.11bn standard may be called UHR PPDUs. Figure 13(C) shows an example of the TB PPDU format specified in the IEEE 802.11be standard and its successor standards. Figure 13(D) shows an example of the format of PPDUs other than TB PPDU (e.g., EHT MU PPDU) specified in the IEEE 802.11be standard and its successor standards. In the TB PPDU shown in Figure 13(C) and the PPDUs other than the TB PPDU shown in Figure 13(D), U-SIG1610 and 1612 are provided, respectively. U-SIG is an abbreviation for Universal SIG. In addition, following U-SIG1610 and 1612, SIG fields specific to each standard may be provided. For example, in the EHT PPDU, EHT-SIG1611 and 1613 may be provided. Also, in the UHR PPDU, UHR-SIG may be provided. The Spatial Reuse field is included in U-SIG1610 in the case of TB PPDU, and in the case of other PPDUs, it may be included in a SIG field specific to the standard (e.g., EHT-SIG1613). In addition, U-SIG1610 and 1612 may include the PHY Version Identifier field, Bandwidth field, BSS Color field, and TXOP field. The PHY Version Identifier field indicates the PPDU type of the PPDU containing this field. For example, in the case of an EHT PPDU, the PHY Version Identifier field may be set to a value of 0.

[0068] The process of determining whether communication using SR or NPCA is possible based on the information contained in the EHT PPDU described above will be explained using Figure 14. First, the communication device 100 identifies the format of the PPDU of the received frame (S1401, S1402). For example, in the case of an EHT PPDU, it can be identified as an EHT PPDU by the PHY Version Identifier field contained in U-SIG1610 and 1612. Note that for PPDUs from the IEEE 802.11be standard onwards (PPDUs after EHT PPDU), the PPDU type can be identified by the PHY Version Identifier field of U-SIG1610 and 1612 (referred to as "EHT or later" in S1402). The communication device 100 determines whether it is a frame of its own BSS or an OBSS frame based on the value of the BSS Color field contained in U-SIG1610 or 1612 (S1443). The communication device 100 uses the Bandwidth field included in U-SIG1610 or 1612 to determine whether a portion of the received frame overlaps with the NPCH used by the device on the frequency axis (S1444). The communication device 100 uses the TXOP field included in U-SIG1610 or 1612 to determine whether the TXOP of the received frame is greater than or equal to a predetermined value (S1445). Then, the communication device 100 uses the Spatial Reuse field included in U-SIG1610 or EHT-SIG1613 to determine whether communication using SR is prohibited (S1446). The communication device 100 may also use other fields included in the PPDU after the EHT PPDU to determine whether communication using SR or communication using NPCA is permitted.

[0069] The communication device 100 can similarly analyze received PPDUs and determine whether communication using SR or NPCA is possible, even for PPDU type frame formats other than HE PPDU and EHT PPDU. For example, the communication device 100 can determine that the PPDU type frame format is HT PPDU as defined in the IEEE 802.11n standard (HT in S1401) based on the modulation scheme of the field following L-SIG1603 included in the received frame. HT is an abbreviation for High Throughput. For example, the communication device 100 can determine that the frame format of this PPDU is HT PPDU based on the fact that the first symbol of the HT-SIG field following L-SIG1603 is modulated using quadrature BPSK. BPSK is an abbreviation for Binary Phase Shift Keying. Quadrature BPSK may be called Quadrature BPSK (QBPSK). In this case, the communication device 100 can determine whether the frame is a BSS frame or an OBSS frame based on the MAC frame information contained in the HT PPDU (S1413). For example, if the information indicating the BSSID contained in the MAC header of the MAC frame matches the BSSID of the BSS, the communication device 100 can determine that it is a BSS frame; otherwise, it can determine that it is an OBSS frame. The communication device 100 can also use the value of the CBW20 / 40 field contained in the HT SIG contained in the received HT PPDU to determine whether a part of the received frame overlaps with the NPCH used by the device on the frequency axis (S1414). Furthermore, the communication device 100 can use the value of the Length field contained in the L-SIG contained in the received HT PPDU to determine whether the TXOP of the received frame is greater than or equal to a predetermined value (S1415). Note that since the HT PPDU does not contain a field indicating whether communication using SR is prohibited, the communication device 100 may determine that communication using SR is possible or not when it receives an HT PPDU.The communication device 100 may also use fields other than those included in the HT PPDU to determine whether or not to perform communication using SR or communication using NPCA (S1416).

[0070] The communication device 100 can determine that the PPDU type frame format is a VHT PPDU as defined in the IEEE 802.11ac standard (VHT in S1402) based on the modulation scheme of the field following L-SIG1603 included in the received frame. VHT is an abbreviation for Very High Throughput. For example, the communication device 100 can determine that this PPDU is a VHT PPDU based on the fact that the first and second symbols of the VHT-SIG field following L-SIG1603 are modulated using BPSK and quadrature BPSK, respectively. In this case, the communication device 100 can determine whether the received PPDU is a frame of its own BSS or an OBSS frame using the Group ID field and Partial AID field of VHT-SIG-A included in the VHT PPDU (S1423). Furthermore, the communication device 100 may use the value of the Bandwidth field included in VHT-SIG-A included in the received VHT PPDU to determine whether a portion of the received frame overlaps with the NPCH used by the device on the frequency axis (S1424). In addition, the communication device 100 may use the value of the Length field included in L-SIG included in the received VHT PPDU to determine whether the TXOP of the received frame is greater than or equal to a predetermined value (S1425). Note that since the VHT PPDU does not contain a field indicating whether communication using SR is prohibited, the communication device 100 may determine whether communication using SR is possible or not when it receives a VHT PPDU. The communication device 100 may also use other fields included in the VHT PPDU to determine whether communication using SR or communication using NPCA is possible (S1426).

[0071] The communication device 100 can determine that a PPDU is a non-HT PPDU as defined in a standard prior to the IEEE 802.11n standard (non-HT in S1401) based on the modulation scheme of the field following L-SIG1603 in the received frame. For example, the communication device 100 can determine that this PPDU is a non-HT PPDU based on the fact that the modulation scheme of the first and second symbols of the field following L-SIG1603 is different from that of the HT PPDU and VHT PPDU described above. In this case, the communication device 100 can determine whether it is a frame of its own BSS or an OBSS frame based on the MAC frame information contained in the non-HT PPDU (S1403). Furthermore, when the communication device 100 receives a non-HT PPDU, it can determine that its bandwidth is 20 MHz (S1404). Furthermore, if the communication device 100 receives a predetermined frame prior to a non-HT PPDU, it may determine the bandwidth of the non-HT PPDU based on that predetermined frame (S1404). For example, if the communication device 100 receives an MU-RTS frame prior to a non-HT PPDU, it may perform processing depending on whether the MU-RTS frame is an HE MU-RTS frame or an EHT or later MU-RTS frame. MU-RTS is an abbreviation for Multi-user Request To Send. As an example, if the communication device 100 receives an HE MU-RTS as defined in the IEEE 802.11ax standard, it may determine the bandwidth of the non-HT PPDU based on the value of the UL BW field in the Common Info field. Also, if the communication device 100 receives an EHT MU-RTS, it may determine the bandwidth of the non-HT PPDU based on a combination of the value of the UL BW field and the value of the Special User Info field in the Common Info field. Furthermore, MU-RTS for EHT can also be used in successor standards to the IEEE 802.11be standard. For example, communication device 100 can determine that the bandwidth of the non-HT PPDU is 20, 40, and 80 MHz when the value of the UL BW field is 0, 1, and 2, respectively.Furthermore, if the value of the UL BW field is 3 and the value of the UL Bandwidth Extension field in the Special User Info field is 1, the communication device 100 may determine that the bandwidth of the non-HT PPDU is 160 MHz. If the value of the UL BW field is 3 and the value of the UL Bandwidth Extension field in the Special User Info field is 2 or 3, the communication device 100 may determine that the bandwidth of the non-HT PPDU is 320 MHz. Also, if the communication device 100 receives a control frame containing the Bandwidth Signaling TA field prior to the non-HT PPDU, it may determine the bandwidth of the non-HT PPDU based on the scrambling sequence. For example, the communication device 100 may determine the bandwidth of the non-HT PPDU based on the values ​​of the CH_BANDWIDTH_IN_NON_HT field or the DYN_BANDWIDTH_IN_NON_HT field in the scrambling sequence. Thus, the communication device 100 can determine the bandwidth of a non-HT PPDU based on a predetermined frame preceding the non-HT PPDU, and if there is no preceding predetermined frame, it can determine that the bandwidth of the non-HT PPDU is 20 MHz. The communication device 100 can determine whether the TXOP of the received frame is greater than or equal to a predetermined value based on the MAC frame information contained in the received non-HT PPDU (S1405). For example, the communication device 100 can determine the length of the TXOP based on the value of the Duration field contained in the MAC header of the MAC frame. Since a non-HT PPDU does not contain a field indicating whether communication using SR is prohibited, the communication device 100 may determine that communication using SR is possible or not when it receives a non-HT PPDU. The communication device 100 may also use other fields contained in the non-HT PPDU to determine whether communication using SR or communication using NPCA is possible (S1406).

[0072] (AP operation flow) The operation of AP101 and STA111 in executing the sequence in Figure 9 will be explained for each communication device. Figure 15 shows an example of a processing flow executed by AP101. This processing flow may be executed based on STA111 initiating a connection procedure to AP101. First, AP101 and STA111 exchange capability information regarding NPCA that each device possesses (S1501). For example, this exchange of capability information may be performed in the connection procedure between AP101 and STA111. AP101 may obtain information indicating whether STA111 is capable of performing communication using NPCA, and the channel switch delay time when STA111 performs NPCA. If STA111 is capable of performing communication using NPCA, AP101 sets the communication parameters for performing communication using NPCA (S1502). For example, AP101 may set the communication parameters for performing NPCA via the frame used in the connection procedure with STA111. Furthermore, AP101 may set communication parameters for performing NPCA-based communication with STA111 using a predetermined management frame after establishing a connection with STA111. The communication parameters for performing NPCA-based communication include information to identify the SPCH, information to identify the NPCH to be used and the frequency band corresponding to that NPCH, and a TXOP threshold for performing NPCA. Based on these communication parameters, AP101 and STA111 can determine whether or not to perform NPCA-based communication.

[0073] AP101 configures settings related to communication using SR (S1503-S1508). For example, if AP101 is performing a MAP coordination procedure with another AP (YES in S1503), it determines whether that MAP coordination procedure includes a request to prohibit communication using SR (S1504). For example, if the MAP coordination procedure performed by AP101 with AP102 includes a request from AP102 to prohibit communication using SR, AP101 configures itself not to perform communication using SR when it receives a frame from an OBSS configured by AP102. For example, if AP101 is requested to prohibit communication using SR (YES in S1504), it issues a notification indicating that communication using SR is prohibited on its own BSS (S1505). For example, when AP101 receives an OBSS frame, it may issue a notification indicating that communication using SR is prohibited, regardless of the BSS from which the OBSS frame was sent. Also, when AP101 receives a frame from a specific OBSS, it may issue a notification indicating that communication using SR is prohibited. For example, if AP101 is requested to restrict communication using SR in a MAP coordination procedure with AP102, it may send a notification indicating that communication using SR is prohibited when it receives a frame from an OBSS configured by AP102. On the other hand, if communication using SR is not prohibited (NO in S1504), AP101 sends a notification indicating that communication using SR is not prohibited in its own BSS (S1505). For example, if AP101 has not received a request to prohibit communication using SR in any of the MAP coordination procedures performed with other APs, it may determine that communication using SR is not prohibited in its own BSS. For example, AP101 may send a notification using a management frame that includes an information element of the Spatial Reuse Parameter set. The information element may be called an Information Element (IE). For example, AP101 may send a Beacon frame that includes a Spatial Reuse Parameter set IE.AP101 may send Probe Response frames, Association Response frames, and Reassociation Response frames that include a Spatial Reuse Parameter set IE. The configuration of the Spatial Reuse Parameter set IE will be described later. AP101 does not need to send a notification indicating that communication using SR is not prohibited in its own BSS if communication using SR is not prohibited. AP101 may send a notification in its own BSS regarding information about MAP coordination procedures performed by its device with other APs (S1507). For example, this information about MAP coordination procedures may include information about restrictions on communication using SR. For example, the information about MAP coordination procedures may include information identifying the BSS composed of APs that performed the MAP coordination procedure in AP101. For example, AP101 may notify STA111 of information indicating whether or not it has received a request to prohibit communication using SR for each OBSS. AP101 does not need to send the notifications performed in S1505 and S1506 if the information about MAP coordination procedures includes information indicating that communication using SR is prohibited. On the other hand, if AP101 separately notifies information regarding restrictions on communications using SR, the information regarding MAP coordination procedures does not need to include information regarding restrictions on communications using SR.

[0074] If AP101 is not performing MAP coordination procedures with other APs (NO in S1503), it notifies STA111 of its policy regarding the execution of communication using SR in its BSS (S1508). For example, AP101 may notify STA111 of information indicating that communication using SR should not be performed if the Spatial Reuse field of the received OBSS frame indicates that communication using SR is prohibited. Alternatively, AP101 may notify STA111 of information indicating that communication using NPCA should be performed instead of communication using SR if the Spatial Reuse field of the received OBSS frame indicates that communication using SR is prohibited.

[0075] Next, AP101 notifies STA111 of reference information used to determine whether to select communication using SR or communication using NPCA (S1509). For example, AP101 may assign a higher priority to communication using NPCA based on having received a request to prohibit communication using SR in the MAP coordination procedure with AP102. In this case, AP101 may notify STA111 of reference information indicating that communication using NPCA should be selected as the priority. AP101 may also assign a higher priority to communication using NPCA based on the received power of the frame received from AP102 being higher than a predetermined threshold. In this case, the predetermined threshold may be the same value as OBSS_PD max and OBSS_PD min shown in Figure 3(A), or it may be a different value. AP101 may also assign a fixed higher priority to communication using SR, or it may also assign a fixed higher priority to communication using NPCA. Furthermore, AP101 may assign higher priority to communications using SR or communications using NPCA based on user input. AP101 may determine the priority between communications using SR and communications using NPCA by methods other than those mentioned above. AP101 may periodically notify STA111 of the reference information generated based on the determined priority, for example, using a Beacon frame.

[0076] When AP101 receives a PPDU, it performs reception processing for that PPDU (S1510). AP101 may also perform analysis processing of the received frame as shown in Figure 14 (S1511). AP101 determines whether the received frame is a local BSS frame or an OBSS frame, and if it is a local BSS frame, it continues reception processing. If the received frame is an OBSS frame, AP101 decides whether to perform communication using SR or NPCA based on the information contained in the received frame (S1512). For example, AP101 may decide whether to perform communication using SR or NPCA based on the determination process shown in Figure 10 or the analysis processing of the received frame shown in Figure 14. Then, AP101 performs communication using the determined communication method (S1513).

[0077] (STA operation flow) Figure 16 shows an example of a processing flow executed by STA111. This processing flow may be executed based on the fact that STA111 is powered on, STA111 detects the presence of AP101, and initiates a connection procedure to AP101. In Figure 16, the same processing as in Figure 15 is given the same reference number and its explanation is omitted. First, STA111 and AP101 exchange capability information regarding NPCA that each possesses (S1501). If AP101 is capable of performing communication using NPCA, STA111 receives the communication parameters for performing communication using NPCA from AP101 (S1601). For example, in the connection procedure with AP101, STA111 may receive the settings of the communication parameters for performing NPCA via the frame used in the connection procedure. Alternatively, STA111 may receive a predetermined management frame containing the communication parameters for performing communication using NPCA after the connection with AP111 is established. STA111 may receive notifications containing information regarding the possibility of communication using SR (S1602). For example, in a MAP coordination procedure between AP101 and AP102, if AP101 is requested by AP102 to prohibit communication using SR, STA111 may receive information indicating that communication using SR is prohibited. Also, if AP101 is not requested to prohibit communication using SR in a MAP coordination procedure with another AP, STA111 may receive information indicating that communication using SR is not restricted. STA111 may receive information from AP101 regarding the MAP coordination procedure performed by AP101 with another AP (S1603). Note that if the information regarding the MAP coordination procedure includes information indicating that communication using SR is prohibited, STA111 does not need to receive the notification containing information regarding the prohibition of communication using SR in S1602. STA111 receives reference information from AP101 to determine whether to choose communication using SR or communication using NPCA (S1604).Based on the communication parameters for performing communication using NPCA received from AP101, information indicating whether communication using SR is possible, reference information, etc., STA111 may execute the processes S1510 to S1513.

[0078] This section describes an example of the frame structure used when AP101 notifies STA111 that communication using SR is prohibited. Figure 17 shows an example of the Spatial Reuse Parameter set IE structure. The Spatial Reuse Parameter set IE may include Element ID 1701, Length 1702, Element ID Extension 1703, and SR Control 1704. It may also include Non-SRG OBSS PD Max Offset 1705, SRG OBSS PD Min Offset 1706, SRG OBSS PD Max Offset 1707, SRG BSS Color Bitmap 1708, and SRG Partial BSS Bitmap 1709. Element ID 1701 and Element ID Extension 1703 are used to identify the type of information element. For example, in the case of Spatial Reuse Parameter set IE, the value 255 may be set for Element ID 1701 and the value 39 for Element ID Extension 1703. Length 1702 indicates the length of IE.

[0079] SR Control 1704 includes PSR Disallowed 1711, Non-SRG OBSS PD SR Disallowed 1712, and Non-SRG Offset Present 1713. SR Control 1704 also includes SRG Information Present 1714, HESIGA_Spatial_reuse_value15_allowed 1715, and Reserved 1716. PSR Disallowed 1711 indicates whether PSR transmission is permitted. For example, a value of 1 for PSR Disallowed 1711 indicates that PSR transmission is prohibited, while a value of 0 indicates that PSR transmission is not prohibited. Non-SRG OBSS PD SR Disallowed 1712 indicates whether OBSS PD transmission is permitted. For example, setting Non-SRG OBSS PD SR Disallowed1712 to a value of 1 indicates that OBSS PD transmission is prohibited, while setting it to a value of 0 indicates that OBSS PD transmission is not prohibited. SRG is an abbreviation for Spatial Reuse Group. An SRG is formed by STAs that use the SRG OBSS PD level when performing communication using SR. An STA that does not belong to an SRG is Non-SRG. AP101 can use PSR Disallowed1711 and Non-SRG OBSS PD SR Disallowed1712 to notify STA111 whether or not communication using SR is permitted. For example, if AP102 requests that communication using SR be prohibited, AP101 can set both PSR Disallowed1711 and Non-SRG OBSS PD SR Disallowed1712 to a value of 1. This allows STA111 to determine that communication using SR is prohibited. AP101 may also be configured to indicate whether or not communication using SR is permitted for each OBSS.For example, AP101 may notify identification information that identifies one or more target OBSSs, in addition to PSR Disallowed1711 and Non-SRG OBSS PD SR Disallowed1712, which are each set to a value of 1. Target OBSSs may be identified by identification information such as BSSID and BSS Color. This allows STA111 to identify that communication using SR is prohibited and to identify the target OBSS. STA111 may determine the BSS from which the OBSS frame was transmitted based on the identification information contained in the BSS of the received OBSS frame. Then, STA111 may determine that if the received frame is a frame transmitted in the target OBSS, communication using SR is prohibited, and if it is not a frame from the target OBSS, communication using SR is not prohibited.

[0080] Non-SRG Offset Present1713 indicates whether Non-SRG OBSS PD Max Offset1705 exists. SRG Information Present1714 indicates whether SRG OBSS PD Min Offset1706~SRG Partial BSSID Bitmap1709 exists. HESIGA_Spatial_reuse_value15_allowed1715 indicates that the value of the Spatial Reuse field may be set to 15 in the PPDU transmitted by STA111. For example, if HESIGA_Spatial_reuse_value15_allowed1715 is set to 1, STA111 may set the value of the Spatial Reuse field to 15 in the PPDU transmitted by its own device. As shown in Figures 5(A) and 5(B), if the value of Spatial Reuse is 15, it indicates that communication using SR should be prohibited. Each of the fields, Non-SRG OBSS PD Max Offset1705 to SRG Partial BSSID Bitmap1709, indicates the communication parameters to be used when transmitting using the OBSS PD method. Note that Spatial Reuse Parameter set IE may include fields other than those shown in Figure 17, and may omit some fields. AP101 may also notify STA111 of restrictions on communication using SR using information elements other than Spatial Reuse Parameter set IE.

[0081] (Example of OBSS sequencing) This section describes a sequence of events performed in OBSS to prevent other BSSs from using SR in their communication. Figure 18 shows an example of a first sequence of events performed in OBSS. In this example sequence, AP102, which constitutes OBSS, instructs STA112 to include information in the Spatial Reuse field of the PPDU that STA112 transmits indicating that communication using SR is prohibited. Based on the instruction from AP102, STA112 includes information in the Spatial Reuse field of the PPDU that it transmits indicating that communication using SR is prohibited. As a result, communication devices in other BSSs that receive the PPDU transmitted by AP102 or STA112 will not use SR in their communication. In addition to the communication sequence between AP102 and STA112, which constitute OBSS, Figure 18 also shows the communication sequence between AP101, which receives the OBSS frame, and STA111.

[0082] First, AP101 and STA111 exchange information for communication using NPCA. For example, AP101 and STA111 exchange information about the NPCA capabilities of their respective communication devices (F1801). AP101 and STA111 also set communication parameters for executing communication using NPCA (F1802). This enables communication using NPCA between AP101 and STA111. AP101 also notifies STA111 of its policy regarding the execution of communication using SR (F1803). In this example, if the Spatial Reuse field of the received OBSS frame indicates that communication using SR is prohibited, AP101 may notify STA111 of information indicating that it will not execute communication using SR. As a result, AP101 and STA111 will each determine whether or not to perform communication using SR based on the value of the Spatial Reuse field of the received OBSS frame.

[0083] Meanwhile, AP102 executes a sequence with STA112 to prevent communication using SR in other BSSs while AP102 or STA112 is transmitting a PPDU. First, AP102 notifies STA112 of information indicating the policy for setting the Spatial Reuse field of the PPDU. For example, if AP102 receives a frame in which HESIGA_Spatial_reuse_value15_allowed1715 is set to 1, it may notify STA112 of information indicating that the value of the Spatial Reuse field of the PPDU should be set to 15. As described above, if STA112 receives a frame in which HESIGA_Spatial_reuse_value15_allowed1715 is set to 1, it can set the value of the Spatial Reuse field of the PPDU it transmits to 15. As a result, communication devices that receive this PPDU will not perform communication using SR. However, even if STA112 receives a frame in which HESIGA_Spatial_reuse_value15_allowed1715 is set to 1, it does not necessarily set the value of the Spatial Reuse field in the PPDU it transmits to 15. For example, even if STA112 receives a frame in which HESIGA_Spatial_reuse_value15_allowed1715 is set to 1, it does not have to set the value of the Spatial Reuse field in the PPDU it transmits to 15. In this case, even after AP102 transmits a frame in which HESIGA_Spatial_reuse_value15_allowed1715 is set to 1, communication using SR in other BSSs is not prohibited while AP102 or STA112 is transmitting the PPDU. Therefore, when AP102 receives a frame in which HESIGA_Spatial_reuse_value15_allowed1715 is set to 1, it issues an instruction to force the value of the Spatial Reuse field in the PPDU to be set to 15.As a result, when STA112 receives a frame in which HESIGA_Spatial_reuse_value15_allowed1715 is set to 1, it will always set the value of the Spatial Reuse field in the PPDU to 15. For example, AP102 may notify STA112 of this policy using a new management frame containing this information. Alternatively, AP102 may notify this policy by creating a new IE in an existing IE such as the Spatial Reuse Parameter Set IE. It is sufficient for a policy indicating that the value of the Spatial Reuse field in the PPDU to be sent to STA112 should be set to 15, using a field different from HESIGA_Spatial_reuse_value15_allowed1715.

[0084] AP102 then notifies STA112 about the setting of the Spatial Reuse field in the PPDU (F1805). For example, AP102 sends a frame containing a Spatial Reuse Parameter Set IE with HESIGA_Spatial_reuse_value15_allowed1715 set to 1. As a result, STA112 sets the value of the Spatial Reuse field in the PPDU it sends to 15. STA112 sends a PPDU with the Spatial Reuse field value set to 15 (F1806). This PPDU can be received by AP102, AP101, and STA111. AP102 sets the value of the Spatial Reuse field to 15 based on the policy it notified STA112 of when it sends a PPDU. As a result, communication devices that receive a PPDU sent by AP102 will not use SR for communication.

[0085] When AP101 and STA111 receive the PPDU transmitted by STA112, they analyze the received PPDU (F1807). For example, AP101 and STA111 may perform the determination process shown in Figure 10 or the analysis process shown in Figure 14. In this example, the Spatial Reuse field of the received OBSS frame indicates that communication using SR is prohibited, so AP101 and STA111 determine that they will not perform communication using SR (for example, S1003). AP101 and STA111 switch the operating channel to NPCH in order to perform communication using NPCA (F1808). Then, AP101 and STA111 perform communication using NPCA (F1809), and when communication is finished, they switch the operating channel back to PCH (F1810). Furthermore, AP101 and STA111 can communicate using NPCA during the period from when BA is transmitted by AP102 until TXOP is completed (F1811).

[0086] Figure 19 shows a second example sequence executed in OBSS. In this example sequence, when STA112 transmits an Uplink (UL) PPDU, AP102 transmits a Trigger frame containing information indicating that communication using SR is prohibited. When STA112 receives the Trigger frame containing information indicating that communication using SR is prohibited, it includes information indicating that communication using SR is prohibited in the Spatial Reuse field of the TB PPDU it transmits. As a result, other BSS communication devices that receive the Trigger frame transmitted by AP102 or the TB PPDU transmitted by STA112 will not perform communication using SR. In Figure 19, the same reference numbers are used for processes similar to those in Figure 18, and explanations are omitted. That is, AP101 and STA111 operate in the same way as in Figure 18. Note that since AP101 and STA111 can receive the Trigger frame transmitted by AP102, they can determine whether or not to perform communication using SR based on the value of the UL Spatial Reuse field contained in the Trigger frame.

[0087] AP102 transmits a Trigger frame (F1901). For example, AP102 may perform access control to enable STA112 to transmit a Trigger frame before STA112 transmits the UL PPDU. As an example, AP102 may set EDCA parameters so that the transmission of the Trigger frame is given priority. AP102 may also control STA112 using a predetermined management frame to prevent it from using EDCA for channel access. The predetermined management frame may be, for example, an Action frame. In this way, by AP102 controlling STA112's EDCA, STA112 will transmit the UL PPDU in response to the Trigger frame from AP102. Note that the UL Spatial Reuse field included in the Trigger frame transmitted by AP102 may be set to a value of 0 to indicate that PSR transmission is prohibited. In this case, STA112 may set the Spatial Reuse field of the TB PPDU transmitted by its device to a value of 0 to indicate that PSR transmission is prohibited.

[0088] When STA112 receives a Trigger frame from AP102, it sends a TB PPDU using the communication parameters specified in the Trigger frame (F1806). For example, if the UL Spatial Reuse field is set to a value of 0 in the Trigger frame, STA112 may send a TB PPDU with the Spatial Reuse field set to a value of 0. Thus, according to the second sequence example, AP102 can control the value of the Spatial Reuse field in the PPDU sent by STA112 without notifying STA112 of information indicating the policy on setting the Spatial Reuse field.

[0089] Figure 20 shows a third example sequence executed in OBSS. In this example sequence, AP102 requests AP101 to prohibit communication using SR. Based on the request from AP102, AP101 notifies AP101 that it will prohibit the execution of communication using SR in its BSS. As a result, AP101 and STA111, which receive PPDUs sent by AP102 and STA112, will not perform communication using SR. In Figure 20, the same reference numbers are used for processes similar to those in Figure 18, and their explanations are omitted.

[0090] First, AP102 performs a MAP coordination procedure with AP101 (F2001). For example, AP102 may request that communication using SR be prohibited during the MAP coordination procedure with AP101. AP101 may respond by indicating that it accepts the request from AP102.

[0091] Based on a request from AP102, AP101 notifies STA111 of its policy regarding the execution of communication using SR (F2002). In this example, AP101 may notify STA111 of information indicating that communication using SR is prohibited, regardless of the value of the Spatial Reuse field in the received OBSS frame. For example, AP101 may notify STA111 using a frame containing Spatial Reuse Parameter set IE. As a result, AP101 and STA111 will execute communication using NPCA instead of SR based on their determination that the received frame is an OBSS frame. Alternatively, AP101 may notify STA111 of information indicating that communication using SR will not be executed when a frame of a specific OBSS configured by AP102 is received. In this case, AP101 and STA111 will execute communication using NPCA instead of SR based on the information indicating the BSS contained in the received frame matching the identification information of the specific OBSS configured by AP102.

[0092] AP102 may execute a sequence with STA112 to prevent communication using SR in other BSSs while AP102 or STA112 is transmitting a PPDU (F1804-F1805). However, AP102 is not required to execute this sequence. Because AP102 requests the prohibition of communication using SR in the MAP coordination procedure with AP101, transmission using SR will not occur regardless of the value of the Spatial Reuse field in the PPDU transmitted by AP102 or STA112. For example, even if STA112 transmits a pre-HE PPDU that does not contain the Spatial Reuse field (F2003), AP101 and STA111 will not communicate using SR. Note that a pre-HE PPDU is a PPDU defined in a standard issued before the IEEE 802.11ax standard.

[0093] When AP101 and STA111 receive a PPDU transmitted by STA112, they determine whether the received PPDU is the PPDU of their own BSS or the PPDU of the OBSS (F2004). AP101 and STA111 may also determine whether the received PPDU is the PPDU of the OBSS configured by AP102 (F2004). Based on the determination of the BSS from which the received PPDU was transmitted, if AP101 and STA111 do not intend to use SR communication, they switch the operating channel to NPCH in order to use NPCA communication (F1808).

[0094] Thus, according to the third sequence example, AP101 and STA111 can determine whether or not to perform communication using SR regardless of the value of the Spatial Reuse field in the PPDU transmitted in OBSS. As a result, even when a PPDU without a Spatial Reuse field is received, the same communication method will be selected between AP101 and STA111. Furthermore, by determining whether or not to perform communication using SR based on the identification information of the BSS from which the received frame was transmitted, it is possible to prevent communication using SR when a frame from a specific OBSS is received.

[0095] (OBSS AP operation flow) The operation of AP102 and STA112 in executing the sequences shown in Figures 18 to 20 will be explained for each communication device. Figure 21 shows an example of the processing flow executed by AP102. First, when AP102 decides to prohibit communication using SR to other BSSs (S2101), it determines whether or not to make a request to other APs using the MAP coordination procedure (S2102). For example, AP102 may determine whether or not AP101 can execute the MAP coordination procedure based on information contained in the Beacon frame etc. transmitted by AP101. If AP101 can execute the MAP coordination procedure, AP102 may decide to attempt the MAP coordination procedure. Also, if AP102 cannot execute the MAP coordination procedure, AP102 may decide not to attempt the MAP coordination procedure. If AP102 decides to attempt the MAP coordination procedure (YES in S2102), it executes the MAP coordination procedure with the other AP (S2103). AP102 requests the other AP to prohibit communication using SR via the MAP coordination procedure, and if coordination is successful (YES in S2104), the process terminates.

[0096] On the other hand, if AP102 determines that it will not attempt the MAP coordination procedure (NO in S2102) or if coordination with the other AP in the MAP coordination procedure is not established (NO in S2104), it will use information included in the transmitted PPDU to prohibit communication using SR. For example, if AP102 uses a Trigger frame to cause STA112 to send a UL PPDU (YES in S2105), it will determine whether it can prevent STA112 from performing EDCA (S2106). As an example, AP102 will determine whether STA112 supports the operation of communicating with AP102 without performing EDCA, and if it does (YES in S2106), it will notify STA112 to prohibit EDCA (S2107). On the other hand, if STA112 does not support this operation (NO in S2106), AP102 will not notify STA112 to prohibit EDCA, but will instead set the EDCA parameters so that the Trigger frame is sent preferentially.

[0097] Furthermore, if AP102 causes STA112 to send a UL PPDU without using a Trigger frame (NO in S2105), it notifies STA112 of information indicating the policy for setting the Spatial Reuse field of the PPDU to be sent. For example, if AP102 receives a frame in which HESIGA_Spatial_reuse_value15_allowed1715 is set to 1, it may notify STA112 of information indicating that the value of the Spatial Reuse field of the PPDU should be set to 15. Then, AP102 notifies STA112 about the setting of the Spatial Reuse field in the PPDU to be sent (S2109). In this way, AP102 can select a method to prevent other BSSs from using SR communication depending on the situation. Note that the method AP102 uses to prevent other BSSs from using SR communication is not limited to this, and for example, the processing flow may not include any of the options, and the order of selection may be different.

[0098] Figure 22 shows an example of a processing flow executed by AP102. This processing flow may be executed when AP102 communicates data with STA112 after the processing flow shown in Figure 21 has been completed. For example, if AP102 has data to send to STA112 on its own device (YES in S2201), it generates a PPDU containing this data (S2202). AP102 may indicate in the Spatial Reuse field of this PPDU that communication using SR is prohibited. Note that if coordination to prohibit communication using SR with other APs has been established in the MAP coordination procedure, AP102 may set the value of the Spatial Reuse field of this PPDU to any value. AP102 sends the generated PPDU (S2203), and when it receives a BA for this PPDU (S2204), it returns to S2201 and continues processing.

[0099] If AP102 has no data to send to STA112 (NO in S2201), it processes data to receive data sent by STA112. For example, if AP102 uses a Trigger frame to cause STA112 to send a UL PPDU (YES in S2205), it generates a Trigger frame (S2206). AP102 may generate a Trigger frame that includes a UL Spatial Reuse field with a value set to indicate that communication using SR is prohibited. If AP102 notifies STA112 of the prohibition of EDCA in S2107 in Figure 21 (YES in S2207), it sends the generated Trigger frame (S2209). On the other hand, if AP102 has not notified STA112 of the prohibition of EDCA (NO in S2207), it sets access parameters so that the Trigger frame is sent preferentially (S2208), and sends the Trigger frame after acquiring the right to send (S2209). When AP102 receives a TB PPDU from STA112 in response to the Trigger frame it transmitted (S2210), it transmits a BA (S2211).

[0100] On the other hand, if AP102 does not send a Trigger frame (NO in S2205), it waits for the reception of a PPDU from STA112 (S2212). If AP102 receives a PPDU from STA112 (YES in SS12), it sends a BA (S2213). If AP102 does not receive a PPDU from STA112 (NO in SS12), it returns to S2201 and continues processing.

[0101] (Operation flow of OBSS STA) Figure 23 shows an example of the processing flow performed by STA112. When STA112 receives a Trigger frame from AP102 (YES in S2301), it generates a TB PPDU using the communication parameters indicated in the received Trigger frame (S2302). If the received Trigger frame contains information indicating that communication using SR is prohibited, STA112 may send a TB PPDU that includes a Spatial Reuse field set to a value indicating that communication using SR is prohibited. When STA112 receives a BA for the sent TB PPDU (S2304), it returns to S2301 and continues processing.

[0102] If STA112 does not receive a Trigger frame and does not receive a Downlink (DL) PPDU sent from AP102 (NO in S2301 and S2305), it determines whether there is data to be sent to its own device (S2306). If there is data to be sent (YES in S2306) and EDCA is not prohibited (NO in S2307), STA112 determines whether it has received instructions to notify that communication using SR is prohibited in the PPDU to be sent (S2308). For example, STA112 determines whether it has received instructions to set the value of the Spatial Reuse field to 15 when it receives a frame in which HESIGA_Spatial_reuse_value15_allowed1715 is set to 1. Also, if STA112 has received such instructions, it determines whether it has received a frame in which HESIGA_Spatial_reuse_value15_allowed1715 is set to 1 after receiving those instructions. If STA112 receives these two messages, it may determine that it has been instructed to include information indicating that communication using SR is prohibited in the PPDU to be transmitted. If STA112 determines that it has been instructed to include information indicating that communication using SR is prohibited in the PPDU to be transmitted (YES in S2308), it generates a PPDU that includes information indicating that communication using SR is prohibited (S2309). If STA112 determines that it has not been instructed to include information indicating that communication using SR is prohibited in the PPDU to be transmitted (NO in S2308), it generates a PPDU that does not include information indicating that communication using SR is prohibited (S2312). STA112 transmits the generated PPDU (S2310), and upon receiving a BA for the transmitted PPDU (S2311), returns to S2301 and continues processing. If STA112 does not have any data to send (NO in S2306) or has received a notification prohibiting EDCA (YES in S2307), it returns to S2301 and continues processing.

[0103] Meanwhile, if STA112 receives a DL PPDU from AP102 (YES in S2305), it processes the reception of that PPDU (S2313). If STA112 successfully receives the PPDU, it sends a BA (S2314) and returns to S2301 to continue processing.

[0104] As described above, the AP in this embodiment notifies reference information to determine whether to select a communication method using SR or NPCA when a radio frame transmitted in OBSS is detected in PCH. The STA in this embodiment also acquires reference information to determine whether to select a communication method using SR or NPCA when a radio frame transmitted in OBSS is detected in PCH. Then, when the AP and STA detect a radio frame transmitted in OBSS in PCH, they determine the communication method to use based on the reference information and communicate. With this configuration, when AP101 and STA111 detect a radio frame transmitted in OBSS on the first channel, they determine the communication method to use based on the same reference information and communicate. As a result, AP101 and STA111 operate on the same channel, reducing the possibility of communication failure due to each communication device operating on different channels. Therefore, AP101 and STA111 can appropriately select between communication using SR and communication using NPCA, enabling efficient use of frequency resources.

[0105] In this embodiment, the communication method that does not use PCH is exemplified as NPCH access, but it is not limited to this, and may be called, for example, Secondary Primary channel access. Also, the reference information that AP101 notifies STA111 may be information other than that described above, and is sufficient if it is information used to determine whether to select communication using SR or communication using NPCA when an OBSS frame is detected in PCH.

[0106] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0107] (Summary of the embodiments) At least some of the embodiments described above can be summarized as follows: (Item 1) A communication device that operates as an access point to communicate with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, A communication means for communicating with the other communication device using a plurality of communication methods, the first communication method configured to enable communication by bonding a first channel and a second channel different from the first channel, the first communication method which communicates on the first channel without using the Spatial Reuse function based on the fact that wireless frames transmitted on the first channel are not detected on the first channel, the second communication method which communicates on the first channel using the Spatial Reuse function based on the fact that wireless frames transmitted on the other BSS are detected on the first channel, and the third communication method which communicates using the second channel without using the first channel based on the fact that wireless frames transmitted on the other BSS are detected on the first channel, The system includes a notification means for notifying reference information used to determine whether the other communication device should select the second or third communication method when a wireless frame transmitted by the other BSS is detected on the first channel, When the communication means detects a wireless frame transmitted on the other BSS on the first channel, it determines the communication method to be used based on the reference information and performs communication. A communication device characterized by the following features. (Item 2) The aforementioned reference information includes information indicating that the second communication method should be selected as preferred. A communication device as described in item 1, characterized by the features described herein. (Item 3) The aforementioned reference information includes information indicating that the third communication method should be selected as preferred. A communication device as described in item 1, characterized by the features described herein. (Item 4) The aforementioned reference information includes information indicating the priority assigned to the second communication method and the priority assigned to the third communication method. A communication device as described in item 1, characterized by the features described herein. (Item 5) The notification means notifies the reference information which includes information indicating predetermined conditions under which the second communication method should not be selected. A communication device as described in item 1, characterized by the features described herein. (Item 6) The aforementioned predetermined condition is satisfied when the wireless frame received from the other BSS includes information indicating that communication using the second communication method is prohibited. A communication device as described in item 5, characterized by the features described herein. (Item 7) The communication means further communicates with the other access points constituting the BSS, When the notification means receives a request from the other BSS to prohibit communication using the second communication method, it notifies the predetermined conditions that are satisfied by receiving a wireless frame containing identification information that identifies it as a wireless frame transmitted by the other BSS. A communication device as described in item 5, characterized by the features described herein. (Item 8) The notification means notifies the reference information which includes information indicating predetermined conditions under which the third communication method should not be selected. A communication device as described in item 1, characterized by the features described herein. (Item 9) The predetermined condition is satisfied when the frequency band used by the radio frame transmitted in the other BSS overlaps with a portion of the frequency band corresponding to the second channel. A communication device as described in item 8, characterized by the features described above. (Item 10) The predetermined condition is satisfied if the time the first channel is used for communication of wireless frames transmitted in the other BSS is less than a predetermined threshold. A communication device as described in item 8, characterized by the features described above. (Item 11) A communication device that operates as a station communicating with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, Communication means for communicating with the other communication device using a plurality of communication methods, including: a first communication method configured to enable communication by bonding a first channel and a second channel different from the first channel, the first communication method which communicates on the first channel without using the Spatial Reuse function based on the fact that wireless frames transmitted on the first channel are not detected on the first channel, a second communication method which communicates on the first channel using the Spatial Reuse function based on the fact that wireless frames transmitted on the other BSS are detected on the first channel, and a third communication method which communicates using the second channel without using the first channel based on the fact that wireless frames transmitted on the other BSS are detected on the first channel; The system includes an acquisition means for acquiring reference information from the other communication device which is used to determine whether the communication device should select the second communication method or the third communication method when a radio frame transmitted in the other BSS is detected in the first channel, When the communication means detects a wireless frame transmitted on the other BSS on the first channel, it determines the communication method to be used based on the reference information and performs communication. A communication device characterized by the following features. (Item 12) The aforementioned reference information includes information indicating that the second communication method should be selected as preferred. A communication device as described in item 11, characterized by the features described herein. (Item 13) The aforementioned reference information includes information indicating that the third communication method should be selected as preferred. A communication device as described in item 11, characterized by the features described herein. (Item 14) The aforementioned reference information includes information indicating the priority assigned to the second communication method and the priority assigned to the third communication method. A communication device as described in item 11, characterized by the features described herein. (Item 15) The acquisition means acquires the reference information which includes information indicating predetermined conditions under which the second communication method should not be selected. A communication device as described in item 11, characterized by the features described herein. (Item 16) The aforementioned predetermined condition is satisfied when the wireless frame received from the other BSS includes information indicating that communication using the second communication method is prohibited. A communication device as described in item 15, characterized by the features described herein. (Item 17) The other communication device communicates with the other access point that constitutes the other BSS. The acquisition means acquires the reference information, which includes information indicating the predetermined conditions that are satisfied when a request is made from the other BSS to prohibit communication using the second communication method, by receiving a wireless frame containing identification information that identifies it as a wireless frame transmitted by the other BSS. A communication device as described in item 15, characterized by the features described herein. (Item 18) The acquisition means notifies the reference information which includes information indicating predetermined conditions under which the third communication method should not be selected. A communication device as described in item 11, characterized by the features described herein. (Item 19) The predetermined condition is satisfied when the frequency band used by the radio frame transmitted in the other BSS overlaps with a portion of the frequency band corresponding to the second channel. A communication device as described in item 18, characterized by the features described herein. (Item 20) The predetermined condition is satisfied if the time the first channel is used for communication of wireless frames transmitted in the other BSS is less than a predetermined threshold. A communication device as described in item 18, characterized by the features described herein. (Item 21) A communication method performed by a communication device that operates as an access point and communicates with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, A communication process for communicating with another communication device using a plurality of communication methods, including: a first communication method configured to enable communication by bonding a first channel and a second channel different from the first channel, the first communication method which performs communication on the first channel without using the Spatial Reuse function based on the fact that wireless frames transmitted on a Basic Service Set (BSS) different from the one configured by the communication device are not detected on the first channel; a second communication method which performs communication on the first channel using the Spatial Reuse function based on the fact that wireless frames transmitted on the other BSS are detected on the first channel; and a third communication method which performs communication using the second channel without using the first channel based on the fact that wireless frames transmitted on the other BSS are detected on the first channel; The system includes a notification step of notifying reference information used to determine whether the other communication device should select the second communication method or the third communication method when a radio frame transmitted by the other BSS is detected on the first channel, The communication process, upon detecting a wireless frame transmitted on the other BSS in the first channel, determines the communication method to be used based on the reference information and performs the communication. A communication method characterized by the following features. (Item 22) A communication method performed by a communication device operating as a station that communicates with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, A communication process for communicating with the other communication device using a plurality of communication methods, including: a first communication method configured to enable communication by bonding a first channel and a second channel different from the first channel, the first communication method which communicates on the first channel without using the Spatial Reuse function based on the fact that wireless frames transmitted on the first channel are not detected on the first channel, a second communication method which communicates on the first channel using the Spatial Reuse function based on the fact that wireless frames transmitted on the other BSS are detected on the first channel, and a third communication method which communicates using the second channel without using the first channel based on the fact that wireless frames transmitted on the other BSS are detected on the first channel; The process includes an acquisition step of acquiring reference information from the other communication device which is used to determine whether the communication device should select the second communication method or the third communication method when a radio frame transmitted in the other BSS is detected in the first channel, The communication process, upon detecting a wireless frame transmitted on the other BSS in the first channel, determines the communication method to be used based on the reference information and performs the communication. A communication method characterized by the following features. (Item 23) A program to cause a computer to function as one of the means of a communication device described in any one of items 1 through 20.

[0108] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of Symbols]

[0109] 101: AP, 102: AP, 111: STA, 112: STA, 121: Network, 122: Network

Claims

1. A communication device that operates as an access point to communicate with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, A communication means for communicating with another communication device using a plurality of communication methods, the first communication method configured to enable communication by bonding a first channel and a second channel different from the first channel, the first communication method which performs communication on the first channel without using the Spatial Reuse function based on the fact that a wireless frame transmitted on a BSS different from the Basic Service Set (BSS) configured by the communication device is not detected on the first channel, the first communication method which performs communication on the first channel using the Spatial Reuse function based on the fact that a wireless frame transmitted on the other BSS is detected on the first channel, and the third communication method which performs communication using the second channel without using the first channel based on the fact that a wireless frame transmitted on the other BSS is detected on the first channel, The system includes a notification means for notifying reference information used to determine whether the other communication device should select the second communication method or the third communication method when a wireless frame transmitted in the other BSS is detected on the first channel, When the communication means detects a wireless frame transmitted on the other BSS on the first channel, it determines the communication method to be used based on the reference information and performs communication. A communication device characterized by the following features.

2. The aforementioned reference information includes information indicating that the second communication method should be selected as preferred. The communication device according to feature 1.

3. The aforementioned reference information includes information indicating that the third communication method should be selected as the preferred method. The communication device according to feature 1.

4. The aforementioned reference information includes information indicating the priority assigned to the second communication method and the priority assigned to the third communication method. The communication device according to feature 1.

5. The notification means notifies the reference information which includes information indicating predetermined conditions under which the second communication method should not be selected. The communication device according to feature 1.

6. The aforementioned predetermined condition is satisfied when the wireless frame received from the other BSS includes information indicating that communication using the second communication method is prohibited. The communication device according to feature 5.

7. The communication means further communicates with the other access points constituting the BSS, When the notification means receives a request from the other BSS to prohibit communication using the second communication method, it notifies the predetermined conditions that are satisfied by receiving a wireless frame containing identification information that identifies it as a wireless frame transmitted by the other BSS. The communication device according to feature 5.

8. The notification means notifies the reference information which includes information indicating predetermined conditions under which the third communication method should not be selected. The communication device according to feature 1.

9. The predetermined condition is satisfied when the frequency band used by the radio frame transmitted in the other BSS overlaps with a portion of the frequency band corresponding to the second channel. The communication device according to feature 8.

10. The predetermined condition is satisfied if the time the first channel is used for communication of wireless frames transmitted in the other BSS is less than a predetermined threshold. The communication device according to feature 8.

11. A communication device that operates as a station communicating with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, Communication means for communicating with the other communication device using a plurality of communication methods, the first communication method configured to enable communication by bonding a first channel and a second channel different from the first channel, the first communication method which performs communication on the first channel without using the Spatial Reuse function based on the fact that a wireless frame transmitted on the first channel is not detected on the first channel, the first communication method which performs communication on the first channel using the Spatial Reuse function based on the fact that a wireless frame transmitted on the other BSS is detected on the first channel, and the third communication method which performs communication on the second channel without using the first channel based on the fact that a wireless frame transmitted on the other BSS is detected on the first channel, The system includes an acquisition means for acquiring reference information from the other communication device which is used to determine whether the communication device should select the second communication method or the third communication method when a wireless frame transmitted in the other BSS is detected in the first channel, When the communication means detects a wireless frame transmitted on the other BSS on the first channel, it determines the communication method to be used based on the reference information and performs communication. A communication device characterized by the following features.

12. The aforementioned reference information includes information indicating that the second communication method should be selected as preferred. The communication device according to feature 11.

13. The aforementioned reference information includes information indicating that the third communication method should be selected as the preferred method. The communication device according to feature 11.

14. The aforementioned reference information includes information indicating the priority assigned to the second communication method and the priority assigned to the third communication method. The communication device according to feature 11.

15. The acquisition means acquires the reference information which includes information indicating predetermined conditions under which the second communication method should not be selected. The communication device according to feature 11.

16. The aforementioned predetermined condition is satisfied when the wireless frame received from the other BSS includes information indicating that communication using the second communication method is prohibited. The communication device according to feature 15.

17. The other communication device communicates with the other access point that constitutes the other BSS. The acquisition means acquires the reference information, which includes information indicating the predetermined conditions that are satisfied when a request is made from the other BSS to prohibit communication using the second communication method, by receiving a wireless frame containing identification information that identifies it as a wireless frame transmitted by the other BSS. The communication device according to feature 15.

18. The acquisition means notifies the reference information which includes information indicating predetermined conditions under which the third communication method should not be selected. The communication device according to feature 11.

19. The predetermined condition is satisfied when the frequency band used by the radio frame transmitted in the other BSS overlaps with a portion of the frequency band corresponding to the second channel. The communication device according to feature 18.

20. The predetermined condition is satisfied if the time the first channel is used for communication of wireless frames transmitted in the other BSS is less than a predetermined threshold. The communication device according to feature 18.

21. A communication method performed by a communication device that operates as an access point and communicates with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, A communication process for communicating with another communication device using a plurality of communication methods, the first communication method configured to enable communication by bonding a first channel and a second channel different from the first channel, the first communication method which performs communication on the first channel without using the Spatial Reuse function based on the fact that a wireless frame transmitted on a BSS different from the Basic Service Set (BSS) configured by the communication device is not detected on the first channel, the first communication method which performs communication on the first channel using the Spatial Reuse function based on the fact that a wireless frame transmitted on the other BSS is detected on the first channel, and the third communication method which performs communication using the second channel without using the first channel based on the fact that a wireless frame transmitted on the other BSS is detected on the first channel, The system includes a notification step of notifying reference information used to determine whether the other communication device should select the second communication method or the third communication method when a wireless frame transmitted by the other BSS is detected on the first channel, The communication process, when it detects a wireless frame transmitted on the other BSS on the first channel, determines the communication method to be used based on the reference information and performs the communication. A communication method characterized by the following features.

22. A communication method performed by a communication device operating as a station that communicates with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, A communication process for communicating with the other communication device using a plurality of communication methods, the first communication method configured to enable communication by bonding a first channel and a second channel different from the first channel, the first communication method which performs communication on the first channel without using the Spatial Reuse function based on the fact that a wireless frame transmitted in a BSS different from the Basic Service Set (BSS) configured by the other communication device is not detected in the first channel, the first communication method which performs communication on the first channel using the Spatial Reuse function based on the fact that a wireless frame transmitted in the other BSS is detected in the first channel, and the third communication method which performs communication using the second channel without using the first channel based on the fact that a wireless frame transmitted in the other BSS is detected in the first channel, The process includes an acquisition step of acquiring reference information from the other communication device which is used to determine whether the communication device should select the second communication method or the third communication method when a wireless frame transmitted in the other BSS is detected in the first channel, The communication process, when it detects a wireless frame transmitted on the other BSS on the first channel, determines the communication method to be used based on the reference information and performs the communication. A communication method characterized by the following features.

23. A program for causing a computer to function as each of the means of the communication device described in claim 1.

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