Communication device, communication method, and program

Abstract

This communication device, which operates as a station (STA) that performs communication conforming to the IEEE 802.11 standard series: transmits, to a partner device that operates as an access point (AP), a trigger frame for transitioning the state of the partner device from a first state in which a first communication parameter can be used to perform communication with the STA to a second state in which a second communication parameter that cannot be used in the first state can be used, the trigger frame storing a predetermined value in an AID12 subfield of a User Info field; and communicates with the partner device that has transitioned to the second state using the second communication parameter.

Description

Communication device, communication method, and program

[0001] The present disclosure relates to power-saving control technology in a wireless LAN.

[0002] Currently, wireless Local Area Networks (LANs) represented by the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series are widely used. The IEEE 802.11 standard series includes standards such as IEEE 802.11a / b / g / n / ac / ax / be. And for further improving communication reliability, the development of the IEEE 802.11bn standard is underway as a successor standard to the IEEE 802.11be standard.

[0003] As one of the candidate technologies defined in the IEEE 802.11bn standard, a technology for suppressing the power consumption of a communication device has been attracting attention (see Non-Patent Document 1). As such a technology, a function called DPS that enables power saving in communication by dynamically changing wireless communication parameters has been studied. Note that DPS is an abbreviation for Dynamic Power Save. A communication device corresponding to DPS can operate while switching between two states: a high-capability state that consumes more power but has high communication quality such as a communication rate, and a low-capability state that suppresses power consumption while reducing communication quality.

[0004] Laurent Carion et al., "Client power save (IEEE 802.11-23 / 2003r1)", IEEE 802.11, 2023

[0005] The present disclosure provides a technology for achieving the efficiency of power consumption of the entire network by using the mechanism of Dynamic Power Save (DPS).

[0006] A communication device according to one aspect of the present disclosure is a communication device that operates as a station (STA) performing communication in accordance with the IEEE 802.11 standard series, and includes a trigger frame for transitioning the state of a remote device operating as an access point (AP) from a first state in which a first communication parameter is available for communication with the STA to a second state in which a second communication parameter that is unavailable in the first state is available, the trigger frame having a predetermined value stored in the AID12 subfield of the User Info field, is transmitted to the remote device, and the communication device communicates with the remote device that has transitioned to the second state using the second communication parameter.

[0007] According to this disclosure, the Dynamic Power Save (DPS) mechanism can be used to achieve efficient power consumption across the entire network.

[0008] Other features and advantages of the technical ideas derived from this disclosure will become apparent from the following description with reference to the attached drawings. In the attached drawings, the same or similar components are given the same reference numeral.

[0009] The attached drawings are included in the specification and constitute part thereof, illustrating embodiments in this disclosure and used to explain the technical ideas derived from this disclosure together with their descriptions. Figure 1 is a diagram showing an example configuration of a wireless communication system. Figure 2 is a diagram showing an example hardware configuration of AP and STA. Figure 3 is a diagram showing the functional configuration of AP and STA. Figure 4 is a diagram showing an example of the communication flow performed in the wireless communication system. Figure 5 is a diagram showing an example of the format of information elements included in the Management frame. Figure 6 is a diagram showing an example of the ICF frame format. Figure 7A is a diagram showing an example configuration of the Common Info field of ICF. Figure 7B is a diagram showing an example configuration of the Common Info field of ICF. Figure 8 is a diagram showing an example configuration of the User Info field of ICF. Figure 9A is a diagram showing an example of the processing flow performed by STA. Figure 9B is a diagram showing an example of the processing flow performed by STA. Figure 10 is a diagram showing an example of the processing flow performed by AP.

[0010] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the scope of the claims. While the embodiments describe multiple features, not all of these features are necessary, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0011] (System Configuration) Figure 1 shows an example of the configuration of a wireless communication system according to this embodiment. The wireless communication system is composed of communication devices that perform communication in accordance with the IEEE 802.11 standard series. Figure 1 shows a state in which there is one access point (AP102) and three stations (STA103, STA104, STA105) as communication devices, but this is just one example. That is, the number of APs may be two or more, and the number of STAs may be two or less or four or more. AP102 forms a network 101 and can transmit signals to STAs (STA103, STA104, STA105) within the range of the network 101 and can also receive signals from those STAs.

[0012] In this embodiment, AP102 and STA103 to STA105 are configured to perform wireless communication using a communication method compliant with the IEEE 802.11bn standard. The IEEE 802.11bn standard is the successor to the IEEE 802.11be standard, and its main features include the realization of functions such as highly reliable communication, low latency communication, improved throughput when communication traffic is congested, and power saving. The wireless frame used in the communication method compliant with this standard may be called a 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 names such as UHR and IEEE 802.11bn may be changed to different names once the standards are finalized. Furthermore, the technologies described herein and in the claims attached herein are applicable to communication devices using all successor standards to IEEE 802.11be.

[0013] Furthermore, AP102 and STA103-STA105 may support at least one legacy standard that predates the IEEE 802.11bn standard and be configured to perform wireless communication compliant with that standard. Legacy standards include, for example, the IEEE 802.11a / b / g / n / ac / ax / be standards. AP102 and STA103-STA105 may also support other communication standards such as Bluetooth®, NFC, Bluetooth® LE (Low Energy), UWB, ZigBee, and MBOA. UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, etc. AP102 and STA103 to STA105 may also be configured to support wired communication using Ethernet cables or optical fibers. AP102 and STA103 to STA105 may also be configured to support wireless communication compliant with cellular communication standards such as fifth generation (5G) and LTE (Long Term Evolution). AP102 may be, but is not limited to, a wireless LAN router or a personal computer (PC). For example, the functions of AP102 described below may be implemented in an information processing device such as a wireless chip capable of performing wireless communication (e.g., transmission and reception of PPDUs) compliant with wireless communication standards such as the IEEE 802.11 standard series, including the IEEE 802.11bn standard. Furthermore, STA (STA103 to STA105) may be, but are not limited to, wearable devices such as cameras, tablets, smartphones, PCs, mobile phones, video cameras, smart glasses, and HMDs (head-mounted displays). For example, the functions of STA described below may be implemented in an information processing device such as a wireless chip that can perform wireless communication (e.g., transmission and reception of PPDUs) compliant with wireless communication standards such as the IEEE 802.11 standard series, including the IEEE 802.11bn standard.When functions are implemented in an information processing device (wireless chip), the device may be configured so that various controls are performed by internal hardware circuits. Alternatively, the wireless chip may be configured so that various processes are performed through the cooperation of a processor such as an ASIP, memory, and hardware circuits within the chip. ASIP stands for Application-Specific Instruction set Processor.

[0014] AP102 and STA103-STA105 can communicate using radio signals in frequency bands such as the 2.4 GHz band, 3.6 GHz band, 5 GHz band, 6 GHz band, and millimeter wave bands such as the 45 GHz band and 60 GHz band. The frequency bands used by AP102 and STA103-STA105 are not limited to these, and may also be the Sub1 GHz band, for example.

[0015] Furthermore, AP102 and STA103-STA105 can communicate using bandwidths (frequency bands) of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by AP102 and STA103-STA105 are not limited to these; for example, bandwidths such as 240 MHz or 4 MHz may be used. Note that the IEEE 802.11 series standard specifies frequency channels using a bandwidth of 20 MHz as basic channels in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands. In addition, this standard defines multiple usable channels in each frequency band of the 2.4 GHz, 5 GHz, and 6 GHz bands. Furthermore, in this standard, a certain channel may be used in combination with other adjacent channels. A bundle of channels formed by one or two or more adjacent channels may be called a communication link (link). That is, in a link formed by two channels with a bandwidth of 20 MHz, a bandwidth of 40 MHz is used. AP102 and STA103 to STA105 may be AP MLDs (Multi-Link Devices) and STA MLDs that support Multi-Link, which establishes multiple links simultaneously for communication.

[0016] AP102 and STA103-STA105 establish one or more links with a peer device in order to communicate data with that peer device. For example, STA103-STA105 perform a predetermined connection procedure with AP102 in order to establish a link with AP102. A link is established between the devices once the predetermined connection procedure between STA103-STA105 and AP102 is completed. Once the link is established, AP102 and STA103-STA105 can access the wireless medium and communicate data and other information with the peer communication device. For example, if one link using a 160 MHz bandwidth is established between the devices, AP102 and STA103-STA105 communicate using all or some of the channels that make up that link. A link using a 160 MHz bandwidth may be composed of eight channels with a 20 MHz bandwidth bundled together.

[0017] As mentioned above, one of the candidate technologies specified in the IEEE 802.11bn standard is a function called DPS, which enables power saving in communication by dynamically changing communication parameters. DPS stands for Dynamic Power Save. In this embodiment, AP102 and STA103 to STA105 are assumed to have the DPS function. Communication parameters changed by DPS include, for example, the frequency bandwidth used for communication, the number of spatial streams, and MCS (Modulation and Coding Scheme). A wireless communication device with the DPS function can operate by switching between two states: a high-capacity state that consumes more power but has higher communication quality such as communication rate, and a low-capacity state that reduces power consumption while lowering communication quality. When the DPS function is used, AP102 can send an Initial Control Frame (ICF) as a trigger frame to an STA in a low-capacity state, causing that STA to transition to a high-capacity state. An ICF is a predetermined frame that can be sent to one or more STAs. By sending a single ICF to multiple STAs, AP102 can simultaneously (in parallel) transition those multiple STAs to a high-capacity state. When an STA receives an ICF, it changes the relevant communication parameters as described above in order to transition to a high-capacity state. Note that an STA may be configured to determine whether to maintain the low-capacity state or transition to a high-capacity state when it receives an ICF. The ICF may include information about the changed values ​​of the communication parameters, and the STA may be configured to change the communication parameters according to that information.

[0018] As described above, by AP102 transmitting an ICF to STA103 to STA105, the power consumption of STA103 to STA105 can be suppressed by transitioning them to a high-capacity state only when necessary. On the other hand, in such a mechanism, AP102 always operates in a high-capacity state and consumes a lot of power. In this embodiment, in order to suppress the power consumption of the entire system, AP102 is also made capable of operating in a low-capacity state. On the other hand, when STA103 to STA105 generate a PPDU to be transmitted, even if the transmission of that PPDU requires the use of communication parameters that can only be used in a high-capacity state, they cannot communicate in a high-capacity state while AP102 is operating in a low-capacity state. For this reason, in this embodiment, STA103 to STA105 are allowed to transmit an ICF to AP102, which is operating in a low-capacity state, in order to request that it operate in a high-capacity state. According to this, AP102 can operate in a high-capacity state only when necessary, thereby suppressing the overall power consumption of the system. In most cases, STA communicates with a small number of APs, such as one. For example, in response to an ICF from one of these APs, STA transitions to a high-capacity state and communicates, and then transitions to a low-capacity state after a predetermined time. Therefore, these few APs can identify the state of STA. On the other hand, since AP102 is expected to communicate with many STAs in parallel, other STAs may not be able to recognize that AP102 has transitioned to a high-capacity state due to an ICF from one of the STAs. In such cases, ICFs may be transmitted unnecessarily, potentially reducing the overall efficiency of the system. For this reason, in this embodiment, a mechanism may also be introduced that allows STA103 to STA105 to recognize the state of AP102, which is compatible with DPS. This allows STA103 to STA105 to identify the state of AP102 and decide whether or not to transmit an ICF according to that state.

[0019] Changes to communication parameters in communication devices (AP102 and STA103-STA105) involve changes to parameters in, for example, the antenna and electrical circuits for transmitting and receiving radio signals. Therefore, a predetermined amount of time is required for these changes to be completed. If another communication device starts communicating on the frequency channel used by the communication device during this predetermined time, it is conceivable that the communication device may not be able to communicate even if it reaches a high-capacity state. For this reason, the ICF includes padding of the same length as or longer than the predetermined time required for the change in communication parameters, so that the communication device can immediately perform communication in a high-capacity state after the predetermined time has elapsed. In a frame with normal padding, the Frame Check Sequence (FCS) is placed after the Padding field. The FCS is a sequence used to confirm that the frame has been received correctly. On the other hand, in DPS, padding is used that corresponds to the time it takes for the communication device to transition from a low-capacity state to a high-capacity state, but if the communication device starts the state transition after receiving up to the FCS, the padding becomes meaningless. On the other hand, if the communication device initiates a state transition in the middle of a frame in order to effectively utilize padding, it will not be able to receive the frame during the state transition period. As a result, the communication device will not be able to receive up to the FCS of the ICF and will not be able to confirm that it has received the frame normally. Therefore, in this embodiment, in order to enable the communication device to receive the FCS while initiating a state transition early, an FCS called an intermediate FCS is placed before the padding. The communication device initiates a state transition after confirming the intermediate FCS contained in the ICF, that is, before receiving the subsequent padding. This allows the communication device to complete the state transition during the padding period of the ICF, and minimizes the time during which the high-capacity state is maintained.

[0020] (Device Configuration) Figure 2 shows an example of the hardware configuration of the communication device (AP102 and STA103 to STA105) in this embodiment. As an example of its hardware configuration, the communication device includes, for example, a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207. Note that these are just examples, and the communication device may have further configurations not shown in Figure 2, or some or all of the configurations shown in Figure 2 may be replaced by other configurations having similar functions.

[0021] The storage unit 201 is configured to include one or more memories such as ROM and RAM. The storage unit 201 stores various information such as computer programs for performing the various operations described later, and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. In addition to memories such as ROM and RAM, the storage unit 201 may also be configured to include 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. Furthermore, the storage unit 201 may be configured to include multiple storage media such as memories.

[0022] The control unit 202 is configured to include, for example, one or more processors such as a CPU and an MPU. CPU stands for Central Processing Unit, and MPU stands for Micro Processing Unit. The control unit 202 controls the entire communication device by executing a computer program stored in the storage unit 201. Alternatively, the control unit 202 may control the entire device through cooperation between the computer program stored in the storage unit 201 and the operating system. The control unit 202 also generates data and signals (wireless frames) to be transmitted in communication with other communication devices. Furthermore, the control unit 202 may be equipped with multiple processors, such as a multi-core processor, and various controls may be performed by multiple processors. The control unit 202 may also be configured to include, for example, an ASIC (Application-Specific Integrated Circuit), a DSP (Digital Signal Processor), or an FPGA (Field-Programmable Gate Array).

[0023] Furthermore, the control unit 202 controls the functional unit 203 to perform predetermined processes such as wireless communication, imaging, printing, and projection. The functional unit 203 is configured to include hardware for the communication device to perform predetermined processes. If the communication device is a printer, the functional unit 203 is a printing device and prints, for example, image data acquired via the communication unit 206. If the communication device is a scanner, the functional unit 203 is a reading device and outputs the scanned image data to the outside, for example, via the communication unit 206. If the communication device is a camera, the functional unit 203 is configured to include an image sensor and a lens and outputs the image data captured by the camera to the outside, for example, via the communication unit 206. The functional unit 203 may also include configurations for realizing AP functions and STA functions.

[0024] The input unit 204 is configured to include, for example, a touch panel, hard keys, buttons, etc., and accepts various operations from the user. The output unit 205 is configured to include a display, speaker, etc., and provides various outputs to the user. Here, the output from the output unit 205 can be a screen display output on the display or an audio output from the speaker. The output unit 205 may also include a vibrator and output information by vibration output. Note that both the input unit 204 and the output unit 205 may be implemented in a single module, such as a touch panel display. The input unit 204 and the output unit 205 may be built into the communication device or implemented by an external input / output device. In this case, the communication device has an input / output interface for connecting to the input / output device.

[0025] The communication unit 206 performs control for wireless communication compliant with the IEEE 802.11 series standard. The communication unit 206 can perform control of wireless communication compliant with, for example, the IEEE 802.11bn standard, its successor standards, or earlier legacy standards, as well as control of wired communication such as wired LAN. The communication unit 206 controls the antenna 207 to send and receive signals for wireless communication generated by the control unit 202. For example, a communication device communicates data such as image data, document data, and video data with a partner device via the communication unit 206. If the communication device supports standards other than the IEEE 802.11 series standard, such as NFC or Bluetooth®, the communication unit 206 may perform control of wireless communication compliant with these communication standards. Furthermore, if the communication device is capable of performing wireless communication compliant with multiple communication standards, separate communication units and antennas corresponding to those communication standards may be provided.

[0026] Antenna 207 is, for example, an antenna capable of detecting and radiating radio waves in the 2.4 GHz band, the 5 GHz band, and the 6 GHz band, respectively. Antenna 207 may also be configured to enable communication in the same frequency band. In this case, antenna 207 may be, for example, a multiband antenna capable of communication in multiple frequency bands. Figure 2 shows an example where the communication device has only one antenna, but multiple antennas may be used, for example, depending on the number of available spatial streams. If the communication device has multiple antennas, it may have a communication unit 206 corresponding to each antenna. Antenna 207 may be provided separately from the communication unit 206, or it may be configured as a single module together with the communication unit 206.

[0027] Figure 3 shows an example of the functional (software) configuration of the communication device (AP102 and STA103 to STA105) of this embodiment. The communication device is configured to include, for example, a wireless LAN control unit 301, a frame generation unit 302, a frame analysis unit 303, a UI control unit 304, a storage control unit 305, and a DPS control unit 306. Note that this functional configuration is just an example, and other functions may be added or the shown functions may be modified. For example, one functional block shown in Figure 3 may be divided into multiple units, or multiple functional blocks may be combined into one. Also, some functions may be omitted, or functions not shown may be added. In one example, at least some of the functions shown in Figure 3 may be realized by the control unit 202 executing a program stored in the storage unit 201. Also, at least some of the functions shown in Figure 3 may be realized using dedicated hardware.

[0028] The wireless LAN control unit 301 controls wireless LAN (Local Area Network) communication. The wireless LAN control unit 301 controls the communication unit 206 and antenna 207 in order to send and receive wireless signals with other communication devices that are capable of wireless LAN communication. For example, the wireless LAN control unit 301 works in cooperation with the frame generation unit 302 and the frame analysis unit 303 to perform wireless frame communication control in accordance with the IEEE 802.11 standard series.

[0029] The frame generation unit 302 generates wireless frames that include MAC frames such as management frames, control frames, and data frames. MAC stands for Medium Access Control. MAC frames are also called MAC Protocol Data Units (MPDUs) or Aggregate MAC Protocol Data Units (A-MPDUs). Wireless frames consist of a preamble field and a data field. MAC frames such as management frames, control frames, and data frames are stored in the data field. Wireless control can be performed by each MAC frame generated by the frame generation unit 302. Here, the content of the wireless control may be constrained by the settings stored in the storage unit 201 by the storage control unit 305. The frame generation unit 302 can also accept settings from the user via the UI control unit 304. The wireless frames generated by the frame generation unit 302 are supplied to the wireless LAN control unit 301 and can be transmitted externally using the communication unit 206 and antenna 207 under the control of the wireless LAN control unit 301. The frame analysis unit 303 analyzes the wireless frames received via the communication unit 206 and antenna 207 under the control of the wireless LAN control unit 301. When analyzing wireless frames, the frame analysis unit 303 can determine the analysis method based on settings stored in the storage unit 201 by the storage control unit 305.

[0030] The UI control unit 304 controls the input unit 204 to accept input to a user interface (UI), such as a touch panel or buttons, for receiving operations on the communication device by a user (not shown). The UI control unit 304 can also control the output unit 205, for example, to perform controls to present information to the user, such as displaying images or outputting sound. The UI control unit 304 can also control the input unit 204 and the output unit 205 to display a graphical UI (GUI) on a display and accept operations on that GUI. The storage control unit 305 controls the storage unit 201 to perform various information storage controls, such as saving, searching, and extracting programs and data on which the communication device operates. The DPS control unit 306 performs controls related to DPS. For example, the DPS control units 306 of STA103 to STA105 perform DPS state changes based on the received ICF and the state of the device itself. The DPS control units 306 of STA103 to STA105 may, for example, determine whether or not to change the DPS state in response to the reception of an ICF. Furthermore, when the DPS control units 306 of STA103 to STA105 change the DPS state, they notify the wireless LAN control unit 301 and the frame generation unit 302 of the change. This causes the wireless frame generated by the frame generation unit 302 to be modified. The wireless LAN control unit 301 also modifies the settings of the communication unit 206 and the antenna 207. As a result, wireless frames corresponding to the modified communication parameters are transmitted using the modified communication parameters. Additionally, the DPS control unit 306 of AP102 controls STA103 to STA105 to generate and transmit an ICF frame in order to perform a state change. The DPS control unit 306 of AP102 can also perform control related to state transitions from a low-capacity state to a high-capacity state. The communication parameters whose range of use in DPS is changed include, for example, the frequency bandwidth available for communication, the maximum number of spatial streams, and the Modulation Coding Scheme (MCS) that can be specified in the communication.

[0031] (Processing Flow) Next, an example of the communication flow performed in a wireless communication system will be explained using Figure 4. In the example in Figure 4, suppose that while AP 102 is operating in a low-capacity state, data requiring high-rate transmission is generated in STA 103 to STA 105. In this case, STA 103 to STA 105 generate a PPDU (S403) while simultaneously transmitting an ICF (S404) to transition AP 102 to a high-capacity state.

[0032] Here, an example of the ICF frame format will be explained using Figure 5. The ICF includes a Frame Control field 501, a Duration field 502, an RA field 503, and a TA field 504. The ICF further includes a Common Info field 505, a User Info field 506, a Padding1 field 507, and an FCS field 508. The fields that are particularly relevant to this embodiment will be described below. Fields that are not specifically described serve the same roles as the fields included in conventional wireless frames, and therefore their descriptions will be omitted here.

[0033] The Common Info field 505 is a field that contains control information common to one or more receivers (in this case, AP102) of this frame. The Common Info field 505 includes at least a Trigger Type subfield 511 and an Intermediate FCS mode subfield 512. An example of the correspondence between the value of the Trigger Type subfield 511 and the type of ICF that the value indicates is shown in the table below. In this embodiment, setting the value of the Trigger Type subfield 511 to 9 indicates that it is an ICF for DPS. The Intermediate FCS mode subfield 512 stores a value indicating whether or not an intermediate FCS is included in the Padding1 field 507. For example, storing "1" in the Intermediate FCS mode subfield 512 indicates that an intermediate FCS exists in the Padding1 field 507. Conversely, storing "0" in the Intermediate FCS mode subfield 512 indicates that there is no intermediate FCS in the Padding1 field 507. Note that this is just one example, and the Intermediate FCS mode subfield 512 may be set to "1" when an intermediate FCS exists in the Padding1 field 507, and to "0" when an intermediate FCS does not exist.

[0034] The Padding1 field 507 is placed after the User Info field 506, which stores control information for the receiver of this frame (in this case, AP102), and is set with padding bits. In Figure 5, an example is shown in which only one User Info field 506 corresponding to AP102 is included in the ICF, but multiple User Info fields may be included in the ICF. In an ICF that includes one User Info corresponding to AP102 and in which an intermediate FCS is set, the FCS field 508 is not interpreted by AP102 and therefore may be omitted. That is, in this case, the FCS field 508 may be replaced by a part of the padding bits in the Padding1 field 507. The Padding1 field 507 is set with padding bits of a length corresponding to the time required for the AP to transition from a low-capacity state to a high-capacity state. In this embodiment, the Padding1 field 507 includes a subfield 513 consisting of two consecutive ones, an Intermediate FCS subfield 514, and a Padding2 subfield 515. The first 12 bits of the Padding1 field being 1 indicate that the User Info field 506 is the last User Info field, and the next field is the Padding1 field 507. The length of the subfield 513 may be other than two octets. The Intermediate FCS subfield 514 may be 32 bits long, but may have other lengths. An AP corresponding to a DPS confirms that a wireless frame has been successfully received by receiving the Intermediate FCS subfield 514, for example, if the ICF contains a User Info field corresponding to its device. Then, once the AP confirms that the wireless frame has been successfully received, it initiates the transition process from the low-capacity state to the high-capacity state. In this case, the AP 102 does not need to interpret the Padding2 subfield 515 and the FCS field 508.The Padding2 subfield 515 is set with padding bits of a length corresponding to the time required for AP 102 to transition from a low-capacity state to a high-capacity state. For example, the padding length is set so that the time from the transmission timing of the Intermediate FCS subfield 514 to the transmission timing of the FCS field 508 corresponds to the time required for AP to transition from a low-capacity state to a high-capacity state. If there are multiple APs that need to transition to a high-capacity state, the padding length may be set based on the longest time required for each of the multiple APs to transition from a low-capacity state to a high-capacity state. This ensures that all target APs are in a high-capacity state when the ICF transmission is completed. The length of the Padding2 subfield 515 (the bit length of the padding bits) may also be specified, for example, before the Padding2 subfield 515 in the Common Info field 505 or the Padding1 field 507.

[0035] The ICF may be a frame defined prior to the IEEE 802.11bn standard, in which the value of the Trigger Type subfield 511 included in the Common Info field 505 is between 0 and 8. Details of the Common Info field 505 in this case are shown in Figure 6. The Common Info field 505 includes the subfields Trigger Type 601, UL Length 602, More TF 603, CS Required 604, and UL BW 605. The Common Info field 505 also includes GI And HE / EHT / UHR-LTF Type / Triggered TXOP Sharing Mode 606 and Reserved 607. Furthermore, Common Info field 505 includes Number Of HE / EHT / UHR-LTF Symbols 608, Reserved 609, LDPC Extra Symbol Segment 610, and AP Tx Power 611. Also, Common Info field 505 includes Pre-FEC Padding Factor 612, PE Disambiguity 613, UL Spatial Reuse 614, and Reserved 615. Furthermore, the Common Info field 505 includes HE / EHT / UHR P160 616 and Special User Info Field Flag 617. The Common Info field 505 also includes Intermediate FCS mode 618 and Trigger Dependent Common Info 619. Here, Intermediate FCS mode 618 is a subfield indicating whether or not the Padding1 field 507 includes an intermediate FCS, similar to the Intermediate FCS mode subfield 512 described above. It may also be indicated that this ICF is a DPS ICF using one of the Reserved fields. For example, setting the value of Reserved615 to "1" may indicate that this ICF is the ICF of DPS.

[0036] Furthermore, if the value of the AID12 subfield (not shown) of the User Info field of the received ICF is a predetermined value, AP102 may interpret that ICF was transmitted to its own device and initiate a state transition (S405). In other words, AP102 changes its settings to enable the communication parameters of the high-capacity state in response to the receipt of the ICF. In this case, the predetermined value is determined in advance as a value corresponding to AP102's AID and may be notified to STA by Beacon frames, Probe Response frames, etc. Alternatively, the predetermined value may be notified to STA by various frames such as Association Response, Authentication Response, and Response Response. The predetermined value may also be a special value for causing the DPS state transition of AP102. In other words, a special value that is not assigned to STA may be used for the ICF related to the DPS state transition. AP102 may also initiate a state transition when it receives an ICF in which the MAC address of AP102 is stored in the RA field 503 and a predetermined value is stored in the AID 12 subfield. Here, the RA field 503 is the field in which the recipient address of that frame is stored. AP102 may also initiate a state transition when it receives an ICF in which the identifier of the network 101 formed by AP102 is stored in the RA field 503 and a predetermined value is stored in the AID 12 subfield. The identifier of the network 101 is the Basic Service Set (BSS) ID (BSSID), etc. Furthermore, these are just examples, and for example, in the Trigger Type subfield 511, a value may be defined to indicate that it is an ICF for transitioning AP to the high-capacity state of DPS (separate from the value indicating that it is an ICF for DPS of STA). Furthermore, AP102 does not need to perform a state transition even if it receives the ICF from DPS.In other words, the ICF of the DPS transmitted from STA103 to STA105 is a frame requesting a state transition of the DPS (a transition to a high-capacity state), and AP102 may approve or reject the request.

[0037] When AP102 completes a state transition, it sends a response frame to STA103 to STA105 to notify them of its approval of the state transition (S406). This response frame may be called an Initial Control Response (ICR) frame, for example. Note that STA103 to STA105 may also be notified of the completion of the state transition by a frame other than the ICR frame. Note that if AP102 does not perform a transition to the high-capacity state, it may send an ICR frame to reject the state transition, or it may not send an ICR frame at all. For example, an Ack frame or an RTS frame may be used as the response frame. In addition, a frame containing communication parameters for after the transition to the high-capacity state may be used in the response frame indicating approval of the state transition. Communication parameters that will be available after the transition to the high-capacity state may be shared in advance between AP102 and each of STA103 to STA105, for example.

[0038] STA103 to STA105 transmit a PPDU to AP102 after receiving the response frame (S407). STA103 to STA105 determine the communication parameters to use for AP102 according to the communication parameters in the high-capacity state. STA103 to STA105 can use communication parameters with a higher communication rate or higher reliability than those used by AP102 in the low-capacity state when communicating with AP102 in the high-capacity state. When AP102 receives the PPDU, it transmits an Ack frame as a response frame to STA103 to STA105 (S408).

[0039] AP102 may revert to a low-capacity state if, for example, no PPDU is received for a certain period of time after transmitting an Ack frame. The time it takes for AP102 to revert to a low-capacity state after transmitting an Ack frame may be pre-set, or this time may be shared in advance between AP102 and STA103 to STA105. The ICF or ICR may also include information indicating the time from transitioning to a high-capacity state to returning to a low-capacity state. The time from transitioning to a high-capacity state to returning to a low-capacity state may also be determined, for example, based on TXOP (Transmission Opportunity). TXOP is set for each access category, and its upper limit is defined as TXOP limit. For example, the set TXOP or the maximum value of TXOP limit may be used as the time from transitioning to a high-capacity state to returning to a low-capacity state. Furthermore, AP102 may transition to a low-capacity state if it does not receive a signal for a certain period of time after an Ack frame is transmitted (i.e., if it determines that there is no data frame to receive).

[0040] Furthermore, information indicating the existence of an intermediate FCS may be included in the Padding1 field 507 instead of the Common Info field 505. For example, the Intermediate FCS mode subfield 512, which is included in the Common Info field 505 in Figure 5, may be placed immediately before the Intermediate FCS subfield 514. That is, the Intermediate FCS mode subfield 512 may be placed immediately after the subfield 513, which consists of two consecutive ones in the two octets of the Padding1 field 507. Note that the length of subfield 513 does not have to be two octets. The lengths of subfield 513 and the Intermediate FCS mode subfield 512 may be predetermined. For example, a combination of subfield 513 being 2 octets and Intermediate FCS mode subfield 512 being 1 bit may be used. Alternatively, a combination of subfield 513 being 12 bits and Intermediate FCS mode subfield 512 being 4 bits may be used. In this way, by pre-determining the combination of lengths for each subfield, AP102 can determine which bit position to interpret as Intermediate FCS mode subfield 512. The storage of a specific value in Intermediate FCS mode subfield 512 indicates that Intermediate FCS subfield 514 is located after it. Otherwise, it indicates that Intermediate FCS subfield 514 does not exist. In this case, the Padding2 subfield 515 is placed immediately after subfield 513. That is, if a specific value is not stored at the position of the Intermediate FCS mode subfield 512, the Intermediate FCS mode subfield 512 may also be treated as not existing.

[0041] When AP102 receives this ICF, it interprets the fields after subfield 513 and determines that the Intermediate FCS mode subfield 512 exists if a predetermined specific value is stored there. Otherwise, STA may determine that neither the Intermediate FCS mode subfield 512 nor the Intermediate FCS subfield 514 exists. Note that the Intermediate FCS mode subfield 512 may always be present. Furthermore, if STA103 to STA105 do not include the Intermediate FCS subfield 514 in the ICF, they may store a value different from the predetermined value in the Intermediate FCS mode subfield 512. In these cases, AP102 can determine that the Padding2 subfield 515 is located immediately after the subfield 513 (or the Intermediate FCS mode subfield 512).

[0042] Furthermore, in the above example, the intermediate FCS may be included in the User Info field. Examples of the User Info field configuration in this case are shown in Figures 7A and 7B. Note that the ICF in Figures 7A and 7B may be configured so that the Common Info field 505 does not include the Intermediate FCS mode subfield 512. Also, a regular padding field may be used instead of the padding1 field 507.

[0043] The User Info field in Figure 7A includes the AID12 subfield 701, the Intermediate FCS mode subfield 702, the Intermediate FCS subfield 703, and the Padding subfield 704. The AID12 subfield 701 stores a specific Association ID (AID), such as a special value used to initiate state transitions in the DPS of AP102. When AP102 receives an ICF, it interprets the User Info field where the value stored in the AID12 subfield is set to a special value associated with the DPS of its own device. Note that an AID may be set for AP102 in advance. On the other hand, AP102 does not interpret (for example, ignores) User Info fields where the value stored in the AID12 subfield does not correspond to its own device. The Intermediate FCS mode subfield 702 is configured similarly to the Intermediate FCS mode subfield 512. For example, if "1" is stored in the Intermediate FCS mode subfield 702, the User Info field includes the Intermediate FCS subfield 703. On the other hand, if "0" is stored in the Intermediate FCS mode subfield 702, the Intermediate FCS subfield 703 does not exist. The Padding subfield 704 may be configured to exist, for example, only when the Intermediate FCS subfield 703 exists. However, this is just one example, and the Padding subfield 704 may be set solely for adjusting the size of the User Info field, regardless of the presence or absence of the Intermediate FCS subfield 703. In this case, the padding corresponding to the state transition time of AP102 may be set in the Padding1 field 507. In this case, the Padding1 field 507 may be set so that the time from the end of the Intermediate FCS subfield 703 of the User Info field corresponding to AP102 to the end of the frame corresponds to the state transition time.Furthermore, for example, the length of the padding bits in the Padding subfield 704 immediately following the Intermediate FCS subfield 703 of the User Info field corresponding to AP102 may be set to correspond to the state transition time.

[0044] The User Info field in Figure 7B further includes the subfields Padding length 705, Request BW 706, Request Nss 707, and Request MCS 708. Padding length 705 stores a value indicating the length of the Padding subfield 704. For example, the value stored in Padding length 705 multiplied by 1 microsecond may be specified as the length of the Padding subfield 704. Alternatively, the value stored in Padding length 705 multiplied by another length (e.g., 32 microseconds) may be specified as the length of the Padding subfield 704. Furthermore, the length of the Padding subfield 704 may be selected from, for example, four default values, and the length may be selectively indicated from these default values ​​by a 2-bit Padding length 705. The number of default values ​​may be more than four, and the bit length of Padding length 705 may be more than 2 bits. Note that information indicating the padding length, such as Padding length 705, does not need to be included in the ICF. For example, by sharing the padding length between AP 102 and STA 103 to STA 105 in advance, this information does not need to be included in the ICF. For example, AP 102 may notify STA 103 to STA 105 in advance, via a Beacon frame or the like, of the padding length corresponding to the time required to transition from a low-capacity state to a high-capacity state. In this case, STA 103 to STA 105 can transmit the ICF including the notified padding length. Furthermore, STA103 to STA105 may send an ICF to AP102 that includes padding longer than the notified length, and also includes information specifying the padding length by Padding length 705.

[0045] Request BW706 stores information regarding the required value of the frequency bandwidth that can be used in communication in the high-capability state after the transition. Request Nss707 stores information regarding the required value of the number of spatial streams that can be used in communication in the high-capability state after the transition. Request MCS708 stores information regarding the required value of the MCS (Modulation and Coding Scheme) that can be used in communication in the high-capability state after the transition. Information regarding the required values of other communication parameters may also be included in the ICF. When the AP102 receives the ICF, it can set the communication parameters that can be used in communication in the high-capability state after the transition based on Request BW706, Request Nss707, and Request MCS708. Also, the AP102 may set the communication parameters in the high-capability state without considering the required values from the STAs 103 to 105. Further, the User Info field may also include cross-link information for enabling communication in another link different from the link to which the ICF is transmitted.

[0046] Note that, as shown in FIG. 4, when the AP102 transitions from the high-capability state to the low-capability state (S402), for example, it notifies the surroundings that it is transitioning to the low-capability state (S401). The AP102 can perform this notification using a management frame including an information element indicating the transition to the low-capability state by the DPS.

[0047] Figure 8 shows an example of an information element included in this management frame. This information element consists of, for example, an Element ID field 801, a Length field 802, and a Capability Mode field 803. The Element ID field 801 stores an identifier indicating that it is an information element that notifies the capability status of AP102. The Length field 802 stores a value indicating the length of this information element. The length shown here is the total length of the Element ID field 801, the Length field 802, and the Capability Mode field 803. The Capability Mode field 803 stores a value indicating the capability status of AP102. For example, if there are two capability states, a high capability state and a low capability state, one bit of information is stored in the Capability Mode field 803. For example, a value of "1" may indicate that AP102 is in a high capability state, and a value of "0" may indicate that AP102 is in a low capability state. Note that this is just one example, and a value of "1" may indicate a low capability state and a value of "0" may indicate a high capability state. In addition to the high capability state and the low capability state, further states may be defined, in which case the Capability Mode field 803 may be provided as a field of two or more bits. Note that even when indicating two states, a high capability state and a low capability state, two or more bits may be provided as the Capability Mode field 803 for future expansion. In S401, AP102 may transmit a management frame in which the Capacity Mode field 803 contains "0" to indicate a low-capacity state, for example, to signal a transition to a low-capacity state. AP102 may also include this information element in periodically transmitted frames, such as Beacon frames. This allows STA, which can receive signals from AP102, to determine whether AP102 is in a high-capacity state or a low-capacity state. AP102 may also transmit a management frame containing this information element in response to a state transition between a low-capacity state and a high-capacity state.

[0048] Next, an example of the processing flow executed by the STA (STA103 to STA105) will be described using FIGS. 9A and 9B. This processing is started, for example, in response to the STA completing the connection process with the AP102.

[0049] First, the STA determines whether it has received a notification indicating the capability state of the AP102 from the AP102 (S901). For example, the STA can recognize the current capability state of the AP102 by observing a wireless frame broadcast by the AP102 in response to a change in the capability state and checking information elements such as those in FIG. 8 included in the wireless frame. Note that the AP102 may periodically transmit information indicating its capability state, for example, by including an information element in a Beacon frame. Also, the STA can transmit frames such as Probe Request, Authentication Request, and Association Request, and receive response messages. Then, the STA may obtain the above-described information elements included in this response message (Probe Response, Authentication Response, Association Response, etc.).

[0050] When STA receives a notification indicating the capability status of AP102 (YES in S901), it identifies the capability status of AP and saves and manages the identified status (S902). Subsequently, STA determines whether data to be sent to AP102 has been generated (S903). Here, it is determined whether data to be sent has been generated while AP102 is in a high capability state. That is, if data that can be sent has been generated while AP102 is in a low capability state, that data can be sent using communication parameters that are usable even in a low capability state, regardless of AP102's capability status, so the following processing may be omitted. Also, Figures 9A and 9B show an example in which it is determined whether data to be sent has been generated (a PPDU to be sent is generated) while no notification indicating the capability status of AP102 has been received (NO in S902), but these may be performed in parallel. In other words, AP102 capability status management and data generation may be performed as unrelated processes. If no transmission data has been generated (NO in S903), STA returns to S901 and waits for the reception of a wireless frame from AP102.

[0051] On the other hand, if STA determines that data to be sent to AP102 has been generated (YES in S903), it checks the capability status of AP102, which is managed in S902 (S904), and determines whether AP102 is operating in a low capability state (S905). If STA determines that AP102 is operating in a high capability state (NO in S905), it sends the PPDU containing the generated data (S911). At this time, STA can send the PPDU using communication parameters that are available in the high capability state. On the other hand, if STA determines that AP102 is operating in a low capability state (NO in S905), it sends an ICF to AP102 requesting that AP102 operate in a high capability state (S906). Note that this ICF may be an instruction that AP102 cannot reject, but here it is assumed to be a request that AP102 can reject. STA then waits for a response frame (ICR) transmitted from AP102 (S907) and determines whether the request has been approved or not based on the ICR (S908). STA may also determine that the request has been rejected if it does not receive an ICR after waiting for a predetermined period. If the request is rejected by the ICR (NO in S908), STA continues communication with AP102 operating in a low-capacity state. That is, STA transmits a PPDU using communication parameters that AP102 can receive in its low-capacity state (S911).

[0052] On the other hand, if STA determines that the request has been approved by ICR (YES in S908), it changes the capability status of the AP102 it manages to a high capability status (S909). Then, STA performs a setting change process to set the communication parameters available to its device to the communication parameters of the high capability status (S910). For example, STA expands the range of usable communication parameters such as frequency bandwidth, spatial stream count, and MCS, and changes the settings to enable high-rate communication and high-reliability communication compared to the low capability status. Then, STA transmits a PPDU containing the generated data using the communication parameters available in the high capability status (S911). After that, STA determines whether or not it has received an Ack frame (e.g., a BlockAck frame) from AP102 (S912). If STA does not receive an Ack (NO in S912), it retransmits the PPDU until the number of transmissions reaches a predetermined number that sets the upper limit for retransmissions (NO in S913, S911). On the other hand, if STA receives an Ack (YES in S912), it does not retransmit or stops retransmitting the PPDU and returns to processing in S901. Also, if STA does not receive an Ack after transmitting the PPDU a predetermined number of times (NO in S912, YES in S913), it terminates the transmission of that PPDU and returns to processing in S901.

[0053] Furthermore, STA may not decide whether or not to transmit an ICF based on whether or not AP102 is in a low-capacity state, but may transmit an ICF requesting a transition to a high-capacity state regardless of AP102's state. In this case, if AP102 receives the ICF while operating in a high-capacity state, it may maintain that capability. Also, STA may, but is not limited to, transmit an ICF at any time when it determines that it is necessary to communicate with AP102 in a high-capacity state. For example, STA may transmit an ICF requesting a transition to a high-capacity state at a timing that has been shared in advance with AP102. For example, AP102 may pre-set a timing at which the transmission of an ICF requesting a transition to a high-capacity state is permitted, and notify STA of this timing information in a management frame. AP102 may, for example, periodically broadcast such timing information to surrounding STAs using a Beacon frame. Furthermore, AP102 may transmit timing information in its Probe Response, which is a response to receiving a Probe Request from STA. AP102 may also individually notify STA of this information via Authentication Response, Association Response, Reassociation Response, etc., during connection or reconnection processing.

[0054] Next, the processing flow performed by AP102 in this embodiment will be explained using Figure 10. This processing is started, for example, when AP102 completes the connection process with STA.

[0055] AP102 determines whether to transition from a high-capacity state to a low-capacity state (S1001). For example, AP102 determines that there is no data to be transmitted in the high-capacity state and no data to be received from STA in the high-capacity state, and decides to transition to a low-capacity state. AP102 does not perform the determination in S1001 while in the low-capacity state. If AP102 determines to transition to a low-capacity state (YES in S1001), it executes a state transition process and limits the range of usable communication parameters to, for example, enable only relatively low-rate communication, and sends a state transition notification to STA (S1002). AP102 may send the state transition notification to STA after the state transition is completed, or it may send the state transition notification to STA before the start of the state transition process or during the process, depending on the decision to perform a state transition. AP102 may also periodically notify the STA of its own device's capacity status using, for example, a Beacon frame.

[0056] If AP102 determines that it will not transition from the high-capacity state to the low-capacity state (NO in S1001), it waits for a radio frame from STA (S1003). If AP102 has not received a radio frame from STA (NO in S1003), it determines whether a transition to the low-capacity state has occurred and waits for the reception of a frame. On the other hand, if AP102 receives a radio frame from STA, it determines whether the radio frame is an ICF requesting a transition to the high-capacity state (S1004). If the received radio frame is an ICF requesting a transition to the high-capacity state (YES in S1004), AP102 determines whether to approve the request (S1005). If AP102 approves the request (YES in S1005), it transitions to the high-capacity state (S1006) and sends a response frame (ICR) containing information indicating approval of the state transition to STA, the source of the ICF (S1007). Then, AP102 returns processing to S1001. If AP102 does not accept the request (NO in S1005), it does not perform state transition processing, sends information indicating rejection of state transition to STA (S1008), and returns processing to S1001. Subsequently, if AP102 receives a PPDU (NO in S1004, YES in S1009), it performs the PPDU reception processing (S1010). This PPDU may be transmitted using communication parameters that are usable in the high-capacity state but not in the low-capacity state, for example, if AP102 has transitioned to the high-capacity state. Also, if AP102 is operating in the low-capacity state, this PPDU may be transmitted using communication parameters that are usable only in the low-capacity state. Then, upon receiving the PPDU, AP102 sends an Ack frame (e.g., a BlockAck frame) to STA (S1011) and returns processing to S1001. Then, AP102 transitions to a low-capacity state, for example, if it has not received a PPDU for a certain period of time (YES in S1001, S1002).

[0057] In the example described above, AP102 immediately transitions to the high-capacity state upon approving an ICF requesting a transition to the high-capacity state, but this is not limited to this example. For example, AP102 may operate to transition to the high-capacity state after a predetermined time has elapsed following the approval of the request. In this case, AP102 may send an ICR to STA containing information specifying the time until the transition to the high-capacity state begins before starting the state transition process to the high-capacity state. AP102 may then execute the state transition process so that it becomes high-capacity at the time indicated by that information. In this case, STA may determine the time when AP102 will transition to the high-capacity state based on the information contained in the ICR, and after the determined time has arrived, it may send a PPDU using communication parameters available in the high-capacity state. In addition, STA may, in one example, control the capability state of its own device so that it transitions to the high-capacity state at a specified time. That is, if STA is operating in the low-capacity state, it may be configured to maintain the low-capacity state until the timing is sufficiently close to the time when PPDU transmission in the high-capacity state is possible. Furthermore, AP102 may include information in the ICR indicating the length of time it will maintain the high-capacity state after transitioning to it, and transmit this information to STA. This allows STA to easily manage the capacity state of AP102. In this case, STA can omit transmitting the ICF while AP102 is operating in the high-capacity state, thereby improving communication efficiency. STA may also include information in the ICF indicating the period during which AP102 should operate in the high-capacity state. AP102 may approve the request in the ICF if it is able to operate in the high-capacity state during that period, and reject the request otherwise. AP102 may also indicate a different period in the ICR. When STA approves the period indicated in the ICR, it transmits a predetermined frame, such as an Ack frame. This enables communication in the high-capacity state for the period negotiated between AP102 and STA. Furthermore, STA may include information in the ICF indicating the length of time during which the high-capacity state should be maintained, rather than a specific period (start and end times).In this case, AP102 may operate to maintain the high-capacity state for a certain period of time after transitioning to the high-capacity state based on the ICF.

[0058] In the processing example described above, if AP102 refuses to transition to the high-capacity state via ICF, STA communicates using communication parameters available in the low-capacity state. However, this is not the only example. For instance, STA may retransmit the ICF and request AP102 to transition to the high-capacity state again. This increases the opportunities for STA to communicate with AP102 in the high-capacity state. The upper limit on the number of ICF retransmissions in this case may be specified in the standard or notified to STA by AP102. This prevents an excessive number of ICF transmission attempts and suppresses a decrease in communication efficiency due to excessive ICF transmission.

[0059] Through the above processing, STA103 to STA105 send an ICF so that AP102 enters the high-capacity state when they wish to send a PPDU using communication parameters that are only available in the high-capacity state. This causes AP102 to transition to the high-capacity state when it is able to accept the request in the ICF, and the STA can send its PPDU using communication parameters that enable higher quality communication, such as high rate and high reliability. Furthermore, after communication in the high-capacity state is completed, AP102 transitions to the low-capacity state when it is no longer necessary to maintain the high-capacity state. This reduces the power consumption not only of the STA but also of the AP, thus reducing the power consumption of the entire system.

[0060] 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 (for example, an ASIC) that implements one or more functions.

[0061] The technical ideas derived from this disclosure are not limited to the exemplary embodiments disclosed, but are intended to encompass various modifications of the exemplary embodiments, or substitutions with equivalent structures or functions. The scope of the following claims should be interpreted in the broadest way to encompass all such modifications and equivalent structures and functions.

[0062] This application claims priority based on Japanese Patent Application No. 2025-004949, filed on 14 January 2025, and all of its contents are incorporated herein by reference.

Claims

1. A communication device that operates as a station (STA) performing communication in accordance with the IEEE 802.11 standard series, wherein the communication device includes a trigger frame for transitioning the state of a remote device operating as an access point (AP) from a first state in which a first communication parameter is available for communication with the STA to a second state in which a second communication parameter that is unavailable in the first state is available, the trigger frame having a predetermined value stored in the AID12 subfield of the User Info field, to the remote device, and a communication means for communicating with the remote device that has transitioned to the second state using the second communication parameter.

2. The communication device according to claim 1, further comprising a management means for managing information indicating whether the other device is operating in the first state or the second state.

3. The communication device according to claim 2, wherein the communication means receives a wireless frame from the other device containing predetermined information indicating the status of the other device, and the management means manages the information indicating the status of the other device based on the predetermined information.

4. The communication device according to claim 2, wherein the communication means receives a wireless frame from the other device containing predetermined information indicating a transition from the first state to the second state, and the management means manages information indicating the state of the other device based on the predetermined information.

5. The communication device according to any one of claims 2 to 4, wherein the communication means transmits the trigger frame to the other device based on the occurrence of data to be transmitted to the other device while the other device is operating in the first state.

6. The communication device according to claim 1, wherein the communication means transmits the trigger frame to the other device, regardless of the state of the other device, based on the occurrence of data to be transmitted to the other device.

7. The communication device according to any one of claims 1 to 6, wherein the first state is a low-capacity state in the Dynamic Power Saving (DPS) function as defined in the IEEE 802.11bn standard, the second state is a high-capacity state in the DPS function, the trigger frame is a frame requesting the other device to transition to the high-capacity state in the DPS function, and the communication means communicates with the other device using the second communication parameter when it receives a response frame to the request from the other device.

8. The communication device according to claim 7, wherein the communication means retransmits the trigger frame when it receives a response frame from the other device indicating that it rejects the request.

9. The communication device according to claim 7, wherein the communication means communicates with the other device using the first communication parameter when it receives a response frame from the other device indicating that it rejects the request.

10. The communication device according to any one of claims 1 to 9, wherein the predetermined value is a special value for state transitions of the counterpart device that is not assigned to STA.

11. The communication device according to any one of claims 1 to 10, wherein the trigger frame includes an Intermediate FCS field.

12. The communication device according to claim 11, wherein the Common Info field of the trigger frame stores information indicating that the Intermediate FCS field is included.

13. The communication device according to claim 1, wherein the communication means transmits to the other device the trigger frame including the second communication parameter as information of a communication parameter that the other device is requesting to make available for use.

14. The communication device according to any one of claims 1 to 13, wherein the communication means transmits the trigger frame to the other device, including cross-link information that enables communication on a link other than the link to which the trigger frame is transmitted.

15. A communication device that operates as an access point (AP) performing communication in accordance with the IEEE 802.11 standard series, comprising: communication means for communicating with a remote device operating as a station (STA); and control means for controlling the communication device to communicate with the remote device in the second state based on the receipt of a trigger frame from the remote device for transitioning the state of the communication device from a first state in which a first communication parameter is available for communication with the STA to a second state in which a second communication parameter that is not available in the first state is available, wherein a predetermined value is stored in the AID12 subfield of the User Info field.

16. The communication device according to claim 15, wherein the first state is a low-capacity state in the Dynamic Power Saving (DPS) function as defined in the IEEE 802.11bn standard, the second state is a high-capacity state in the DPS function, and the trigger frame is a frame that requests the other device to transition to the high-capacity state in the DPS function.

17. The communication device according to claim 16, wherein the control means determines whether to approve or reject the transition to the high-capacity state when it receives the trigger frame; the communication means transmits a response frame containing information indicating approval of the transition to the high-capacity state to the other device when it approves the transition to the high-capacity state while operating in the low-capacity state; the communication means transmits a response frame containing information indicating rejection of the transition to the high-capacity state to the other device when it rejects the transition to the high-capacity state; and the control means performs the transition to the high-capacity state when it approves the transition to the high-capacity state while operating in the low-capacity state.

18. The communication device according to any one of claims 15 to 17, wherein the predetermined value is a special value for state transitions of the communication device that is not assigned to STA.

19. The communication device according to any one of claims 15 to 18, wherein the trigger frame includes an Intermediate FCS field.

20. The communication device according to claim 19, wherein the Common Info field of the trigger frame stores information indicating that the Intermediate FCS field is included.

21. The communication device according to any one of claims 15 to 20, wherein the trigger frame includes the second communication parameter as information of a communication parameter that the other device requests to be made available to the communication device.

22. The communication device according to any one of claims 15 to 21, wherein the trigger frame includes cross-link information for enabling communication on a link other than the link on which the trigger frame is transmitted.

23. A communication method performed by a communication device operating as a station (STA) that performs communication in accordance with the IEEE 802.11 standard series, comprising: transmitting to the remote device a trigger frame for transitioning the state of a remote device operating as an access point (AP) from a first state in which a first communication parameter is available for communication with the STA to a second state in which a second communication parameter that is unavailable in the first state is available, wherein the trigger frame has a predetermined value stored in the AID12 subfield of the User Info field; and communicating with the remote device that has transitioned to the second state using the second communication parameter.

24. A communication method performed by a communication device that operates as an access point (AP) performing communication in accordance with the IEEE 802.11 standard series and communicates with a remote device operating as a station (STA), the method comprising: receiving a trigger frame from the remote device to transition the state of the communication device from a first state in which a first communication parameter is available for communication with the STA to a second state in which a second communication parameter that is not available in the first state is available, the trigger frame having a predetermined value stored in the AID12 subfield of the User Info field, and then communicating with the remote device in the second state.

25. A program for causing a computer to function as each of the means of the communication device described in any one of claims 1 to 14.

26. A program for causing a computer to function as each of the means of the communication device described in any one of claims 15 to 22.

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