Access point device, station device, control method, and program

Abstract

To provide a mechanism for access points to operate in a power-saving manner, as one of objectives.SOLUTION: An access point device that performs wireless communication based on the IEEE802.11 standards determines, when operating in an enhanced multi-link single radio (EMLSR) mode, whether a frame of a predetermined type has been received from a station device connected to the access point device. If the access point device determines that a frame of the predetermined type has been received, the access point device cancels the EMLSR mode and performs data communication with the station device. After the data communication is completed, the access point device shifts its operation mode to the EMLSR mode.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to an access point device and a station device for communicating data. [Background technology]

[0002] In recent years, with the increase in the amount of data being communicated, the development of communication technologies such as wireless LANs (Local Area Networks) has been progressing. The IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series is known as the main communication standard for wireless LANs. The IEEE 802.11 standard series includes standards such as IEEE 802.11a / b / g / n / ac / ax.

[0003] In addition, the IEEE802.11be standard, which is the successor to the IEEE802.11ax standard, is being developed. As a new function of the IEEE802.11be standard, a function such as Multi-Link communication, in which an AP and a STA establish multiple links with different frequency channels and communicate in parallel, is being considered. In addition, Patent Document 1 describes a mechanism for establishing multiple links for Multi-Link operation.

[0004] Furthermore, the specifications of the IEEE802.11bn (UHR (Ultra High Reliability) standard, which is the successor to the IEEE802.11be standard, are also under consideration. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-103805 Summary of the Invention [Problem to be solved by the invention]

[0006] In Multi-Link operation, the STR (simultaneous transmit and receive) mode is specified, which allows communication devices to transmit and receive frames simultaneously over multiple links. In this mode, multiple links are put on standby for communication, resulting in high power consumption. Therefore, the IEEE802.11be standard specifies the EMLSR (enhanced multi-link single radio) mode as one method of saving power in communication devices. This mode is specified only for non-AP MLD (non-access point multi-link device) in the IEEE802.11be standard. In other words, the application of the EMLSR mode to AP MLD (access point multi-link device) is not specified at present.

[0007] While operating in this EMLSR mode, the non-AP MLD waits to receive an initial control frame sent by the AP MLD simultaneously on multiple links (EMLSR links) established with the AP MLD.

[0008] Here, different channels are generally selected for each EMLSR link. Then, AP MLD selects one link and transmits an initial control frame on that link. At this time, AP MLD selects the optimal link (for example, a link that uses an uncrowded channel) and transmits the initial control frame. When non-AP MLD receives the initial control frame, it exchanges data with AP MLD on the link that received it. While operating in EMLSR mode, non-AP MLD does not transmit or receive simultaneously on multiple links. Therefore, non-AP MLD can save power consumption while still exchanging data with AP MLD when triggered by receiving an initial control frame.

[0009] However, as mentioned above, no method of reducing power consumption for AP MLD, including the EMLSR mode, has been specified, and reducing power consumption for AP MLD is one of the topics under discussion in the specification review of the IEEE802.11bn standard.

[0010] In order to reduce the power consumption of AP MLD, it is desirable to be able to quickly respond to changes in the throughput or transmission delay required by non-AP MLDs connected to the AP MLD while also achieving power saving. However, no method for achieving this has been considered at present.

[0011] The present invention has been made in consideration of at least one of the above problems. One of the objects of the present invention is to operate AP MLD in a power-saving manner while quickly responding to changes in the throughput or transmission delay amount required by non-AP MLD. Another object of the present invention is to provide a mechanism for AP MLD to perform a power-saving operation. [Means for solving the problem]

[0012] An access point device as one aspect of the present invention is an access point device that performs wireless communication based on the IEEE 802.11 standard, and is characterized in having: a judgment means for judging whether a frame of a predetermined type has been received from a station device connected to the access point device when the access point device is operating in an enhanced multi-link single radio (EMLSR) mode; a communication control means for canceling the EMLSR mode and performing data communication with the station device when the judgment means judges that a frame of the predetermined type has been received; and a transition means for transitioning to the EMLSR mode after data communication has been performed by the communication control means. Effect of the Invention

[0013] According to one aspect of the present invention, it is possible to quickly respond to changes in the throughput or transmission delay required by non-AP MLD while operating AP MLD in a power-saving manner. Also, as another aspect of the present invention, it is possible for AP MLD to perform a power-saving operation. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 illustrates an example of a configuration of a network system. [Diagram 2] A diagram illustrating an example of the hardware configuration of a communication device (AP MLD / non-AP MLD). [Diagram 3] A diagram illustrating an example of the functional configuration of a communication device (AP MLD / non-AP MLD). [Figure 4] 13 is a flowchart showing an example of AP MLD control. [Diagram 5] FIG. 2 is a schematic diagram showing an example of information elements to be communicated. [Figure 6] FIG. 2 is a schematic diagram showing an example of information elements to be communicated. [Figure 7] FIG. 2 is a schematic diagram showing an example of information elements to be communicated. [Figure 8] 13 is a flowchart showing an example of non-AP MLD control. [Figure 9] 13 is a flowchart showing an example of AP MLD control. [Figure 10] 13 is a flowchart showing an example of non-AP MLD control. [Figure 11] FIG. 2 is a schematic diagram illustrating the relationship between modes and power saving. [Figure 12] FIG. 13 is a schematic diagram illustrating the relationship between the EMLSR mode and power saving. [Figure 13] FIG. 13 is a schematic diagram illustrating a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0016] <First embodiment> An example of the configuration of a network system according to this embodiment is shown in Fig. 1. The network system according to this embodiment includes one access point device (hereinafter, also simply referred to as AP, AP STA, or access point) and two station devices (hereinafter, also simply referred to as STA, Non-AP STA, or stations).

[0017] The AP 101 and the STA 102 are configured to be capable of communicating wireless frames conforming to the IEEE802.11bn standard, which is the successor to the IEEE802.11be standard and has a target maximum transmission speed of 46.08 Gbps.

[0018] IEEE is an abbreviation for the Institute of Electrical and Electronics Engineers. The main features of IEEE802.11bn, the successor standard to IEEE802.11be, are highly reliable communication, low latency communication, and improved throughput during congestion. Another goal of 802.11bn is to reduce power consumption in APs. Wireless frames communicated under this successor standard are also called UHR (Ultra High Reliability) PPDU. PPDU is an abbreviation for Physical Layer Protocol Data Unit.

[0019] The name UHR is a name given for convenience in consideration of the goals and features of the successor standard, and may be a different name when the standard is completed. Similarly, the name IEEE802.11bn may be a different name when the standard is completed. However, it should be noted that this specification and the appended claims are essentially applicable to all successor standards that are successors to the 802.11be standard.

[0020] Returning to the description of Fig. 1, the AP 101 is an access point that supports a multi-band function that provides a network using a plurality of different frequency channels. In this embodiment, the AP 101 is a dual-band access point that provides a 2.4 GHz band network and a 5 GHz band network, for example.

[0021] Furthermore, the AP 101 and the STA 102 of this embodiment can establish multiple communication links between the devices and perform Multi-Link communication for communication. Hereinafter, the communication link is also simply called a link. The AP 101 that performs Multi-Link communication is also called an AP Multi-Link Device (AP MLD) 101, and the STA 102 that performs Multi-Link communication is also called a non-AP MLD 102.

[0022] For example, AP 101 can establish link 103 in a 2.4 GHz band network with STA 102 and communicate with it. In addition, AP 101 and STA 102 can establish link 104 in the 5 GHz band in parallel with this and communicate with it. In this case, STA 102 executes Multi-Link communication in which it communicates also via link 103 in parallel with link 104. In this embodiment, for convenience, the mode in which two communication links are established and simultaneous communication is called a normal mode of Multi-Link Operation. Hereinafter, Multi-Link Operation is also called MLO.

[0023] In this embodiment, the normal mode is assumed to be an STR (simultaneous transmit and receive) mode in which the STA and the AP can simultaneously transmit and receive using two or more links. However, the normal mode is not limited to this. For example, the normal mode may be an NSTR mode in which a restriction is imposed such that a link pair of Multi-Link Operation must be used for simultaneous transmission or simultaneous reception, and the AP 101 and the STA 102 communicate under this restriction. NSTR is an abbreviation for nonsimultaneous transmit and receive.

[0024] In this way, the AP 101 can improve the throughput of communication with the STA 102 by establishing links with the STA 102 on multiple different frequency channels.

[0025] Incidentally, non-AP MLD conforming to the IEEE802.11be standard can also operate in a multi-link operation mode called EMLSR (enhanced multi-link single radio) mode. A non-AP MLD operating in this mode establishes an EMLSR link with an AP MLD. In the EMLSR mode, the link used for actual data communication is regarded as one link, but the link actually used for communication can be dynamically switched in consideration of the congestion status of the wireless channel and the like. The non-AP MLD 102 of this embodiment also supports the EMLSR mode. The non-AP MLD 102 operating in the EMLSR mode and on standby for communication operates in a state in which it scans the communication status of each channel of the EMLSR link. A non-AP MLD operating in a state in which it scans the communication status in the EMLSR mode does not transmit simultaneously on multiple links or wait to receive frames other than the initial control frame while operating in that state.

[0026] Data communication of user data, etc. using the EMLSR link between the AP MLD 101 and the non-AP MLD 102 is triggered by the transmission of an initial control frame and starts. For example, when the non-AP MLD 102 detects by scanning that it has received an initial control frame from the AP MLD 101, it activates the link that received the frame in order to transmit data, such as user data. Then, data communication of user data, etc. is performed with the AP MLD over the activated link. With this mechanism, the non-AP MLD 102 can exchange data with the AP MLD with high throughput or low latency while saving power consumption.

[0027] Incidentally, power saving of AP MLD is one of the topics under discussion in the specification of the IEEE802.11bn standard. In view of this, in this embodiment, the concept of EMLSR mode is also applied to AP MLD 101. In this case, a mechanism is provided that enables power saving operation on the AP side by EMLSR mode and can quickly respond to changes in the throughput or transmission delay required by non-AP MLD connected to the AP MLD.

[0028] A specific description will be given below. In FIG. 1, a network system consisting of one AP MLD 101 and one non-AP MLD 102 is shown as an example, but the number of non-AP MLDs constituting the network system may be greater than that shown. In addition, the AP MLD 101 and non-AP MLD 102 are described as supporting UHR PPDU communication (transmission and reception), but in addition to this, they can also be configured to support PPDU communication of a legacy standard that is a standard that precedes the UHR standard. Specifically, the AP 101 and STA 102 can also be configured to support PPDU transmission and reception of the IEEE802.11a / b / g / n / ac / ax / be standard, etc.

[0029] Moreover, the frequency bands used by the AP MLD 101 and the non-AP MLD 102 are not limited to the 2.4 GHz band and the 5 GHz band described above. For example, different frequency bands such as the 6 GHz band, the Sub1 GHz band, and the millimeter wave band may be used. Moreover, the AP 101 and the STA 102 can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, and the like. The bandwidths used by each communication device are not limited to these. Moreover, in this embodiment, a case is illustrated in which the links 103 and 104 that perform Multi-Link communication are links of different frequency bands, but the present invention is not limited to this. The AP MLD 101 can also perform Multi-Link communication with the non-AP MLD 102 using multiple links of the same frequency band and different channels.

[0030] The AP MLD 101 and the non-AP MLD 102 can also be configured to support wireless communication based on other communication standards such as Bluetooth (registered trademark), NFC, and Bluetooth (registered trademark) LE (Low Energy). NFC stands for Near Field Communication. The AP 101 and the STA 102 can also be configured to support wired communication using an Ethernet (registered trademark) cable or wired communication using optical fiber. Specific examples of the AP 101 include, but are not limited to, a wireless LAN router and a personal computer (PC). The AP MLD 101 and the non-AP MLD 102 may be information processing devices such as wireless chips that support the transmission and reception of UHR PPDU. In this case, the AP MLD 101 and the non-AP MLD 102 can be configured to execute various controls using hardware circuits inside the wireless chip. The AP MLD 101 and the non-AP MLD 102 can also be configured to execute various processes by cooperation between a processor, memory, and hardware circuits such as an ASIP inside the wireless chip. ASIP stands for Application-specific instruction set processor.

[0031] Specific examples of the STA 102 include, but are not limited to, cameras, tablets, smartphones, PCs, mobile phones, video cameras, and wearable devices such as smart glasses.

[0032] <Hardware configuration of communication device> 2 shows an example of the hardware configuration of a communication device (AP MLD 101, non-AP MLD 102). The communication device includes 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 antennas 207-208 as an example of the hardware configuration.

[0033] The storage unit 201 is configured with both or either one of a ROM and a RAM, and stores various information such as programs for performing various operations described below and communication parameters for wireless communication. RAM stands for Random Access Memory, and ROM stands for Read Only Memory. Note that, as the storage unit 201, in addition to memories such as ROM and RAM, storage media such as non-volatile storage devices such as hard disks and SSDs (Solid State Drives) may be used.

[0034] The control unit 202 is configured with, for example, a processor such as a CPU or MPU, an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), etc. Here, CPU stands for Central Processing Unit, and MPU stands for Micro Processing Unit. The control unit 202 executes the programs stored in the storage unit 201 and controls the entire device by operating hardware circuits such as the ASIC. The control unit 202 may control the entire device in cooperation with the programs stored in the storage unit 201 and an OS (Operating System).

[0035] The control unit 202 controls the functional unit 203 to perform predetermined processing such as imaging, printing, and projection. The functional unit 203 is hardware for the device to perform predetermined processing. For example, when the communication device is a camera such as a digital still camera or a smartphone having a camera, the functional unit 203 is an imaging unit that performs imaging processing of surrounding images via a camera unit (not shown) of the communication device. For example, when the communication device is a printer, the functional unit 203 is a printing unit that performs printing processing on a sheet such as paper based on print data obtained from the outside through wireless communication. For example, when the communication device is a projector or smart glasses, the functional unit 203 is a projection unit that performs projection processing of image data or video data obtained from the outside through wireless communication. In the case of smart glasses, the projection surface is the retina of an end user. The data processed by the functional unit 203 may be data stored in the storage unit 201, or may be data communicated with other APs or STAs via the communication unit 206 described later. Furthermore, a communication device such as the AP 101 can provide a network storage function such as a NAS (Network Attached Storage). This function is provided to other communication devices as a Web service such as a network storage service. For example, a communication device such as an STA connects to a network storage service provided by an AP MLD 101 or the like using a protocol such as SMB, FTP, or WebDAV. The communication device such as an STA then uploads files to the storage service and downloads files from the storage. The data communication for uploading and downloading is also realized by communicating UHR PPDU between devices.

[0036] The input unit 204 receives various operations from the user. The output unit 205 performs various outputs to the user. Here, the output by the output unit 205 includes, for example, at least one of display on a screen, audio output by a speaker, and vibration output. Note that both the input unit 204 and the output unit 205 may be realized by one module, such as a touch panel. The output unit 205 functions as a display unit that presents information to the user. The input unit also functions as a receiving unit that receives user operations.

[0037] The communication unit 206 controls wireless communication conforming to the IEEE802.11 standard series and IP communication. In this embodiment, the communication unit 206 can execute communication control for transmitting and receiving UHR PPDU, which is a wireless frame of the UHR standard, and PPDU corresponding to the previous standard in cooperation with the antennas 207-208. The antennas 207-208 are antennas capable of transmitting and receiving signals in at least one of the frequency bands of the sub-GHz band, the 2.4 GHz band, the 5 GHz band, the 6 GHz band, and the millimeter wave band, for example. Note that, in this embodiment, a communication device having two antennas is illustrated as an example, but is not limited to this. The number of antennas may be three or more.

[0038] If the communication device is compatible with the above-mentioned NFC standard, Bluetooth standard, wired communication standard, etc., the communication unit 206 may be configured to control wireless communication and wired communication in accordance with these communication standards. The communication units 206 of the AP MLD 101 and non-AP MLD 102 each have a hardware circuit that decodes or encodes a signal communicated through each link. Each antenna and hardware circuit is configured to be capable of individual power control. It is also possible to configure the device to have a separate communication unit corresponding to each link.

[0039] Next, the functional configuration of the AP MLD 101 and non-AP MLD 102 will be described with reference to Fig. 3. The communication devices such as the AP MLD 101 and non-AP MLD 102 have functional units such as a multi-link control unit 301, a multi-link communication setting UI unit 302, a frame generation unit 305, and a frame transmission / reception unit 306.

[0040] The multi-link control unit 301 is a functional block that controls communication start processing for establishing one or more links used by a communication device for wireless communication with a partner device, mode determination, change processing, link addition / deletion processing after communication start, and communication end processing for deleting all links. Specifically, the connection processing is composed of authentication processing, association processing, and 4-way-handshake processing. In the case of AP MLD 101, the partner device is an STA such as non-AP MLD 102, and in the case of non-AP MLD 102, the partner device is an AP such as AP MLD 101. The multi-link control unit 301 also controls the power saving mode. Specifically, when the power saving mode is enabled, the power control is performed, such as stopping the power supply to some hardware circuits.

[0041] The multi-link communication setting UI (User Interface) unit 302 provides a setting screen as a UI for the user to input settings related to Multi-Link communication. The UI unit 302 is also a functional block that accepts a user operation on the setting screen via the input unit 204 and stores the setting in the storage unit 201 as an operation setting of the communication device. The UI unit 302 accepts a setting change operation for determining whether or not to enable a power saving mode via a setting screen (not shown). The UI unit 302 also stores an operation setting related to the AP power saving mode corresponding to the setting change operation in the storage unit 201. The operation setting is used as appropriate for determining whether or not to execute the control of a flowchart described later.

[0042] Returning to the description of FIG. 3, the frame generation unit 305 is a UHR PPDU which is a wireless frame for communicating with the outside or a block to be generated. The frame transmission / reception unit 306 transmits the wireless frame generated by the frame generation unit 305 and receives the wireless frame from the counterpart device. In the case of the non-AP MLD102, it transmits a Probe Request frame, an Association Request frame, a data frame, etc. to the AP. Also, the non-AP MLD102 transmits an Authentication Request frame and other frames for connection processing to the AP. Also, it transmits an RTS (Request To Send) frame, an NDP (Null data PPDU) frame, an EML (enhanced multi-link) Operating Mode Notification frame to the AP. Also, it transmits an initial control frame to the AP.

[0043] In the case of the AP MLD101, it transmits a Beacon frame, a Probe Response frame, an Association Response frame, a data frame, etc. to the STA. Also, the AP MLD101 transmits an Association Request frame, an Authentication Request frame, and other frames for connection processing, etc. to the STA. Also, it transmits the aforementioned initial control frame to the STA as a non-AP MLD.

[0044] <Communication control utilizing the EMLSR mode> Subsequently, the communication control utilizing the EMLSR mode of the present embodiment will be described using the flowcharts of FIGS. 4, 8 to 10 and the schematic diagrams of information elements of FIGS. 5 to 7.

[0045] Figures 4 and 9 are flowcharts illustrating an example of communication control in AP MLD 101, and Figures 8 and 10 are flowcharts illustrating an example of communication control in non-AP MLD 102. Figures 5 to 7 are schematic diagrams illustrating information elements communicated between devices.

[0046] Each process shown in the flowcharts of Fig. 4 and Fig. 9 is executed by the processor of the control unit 202 of the AP MLD 101 executing a computer program stored in the storage unit 201. Note that some processes such as transmission and modulation are realized by the processor of the control unit 202 and various processors, ASIC, DSP, FPGA, antenna, and ASIC, DSP, FPGA, etc. constituting the communication unit 206 in cooperation with each other. Note that this is not limited to this, and it is of course possible to configure the communication unit 206 and the antenna to cooperate to execute each process shown in the flowcharts. Note that when it is desired to clearly indicate the subject of the process, the functional unit described in Fig. 3 will be described as the subject.

[0047] 8 and 10 are executed by the processor of the control unit 202 of the non-AP MLD 102 executing a computer program stored in the storage unit 201. Some of the processes, such as transmission and modulation, are realized by the processor of the control unit 202 in cooperation with various processors, ASICs, DSPs, FPGAs, etc., that constitute the communication unit 206, and the ASICs, DSPs, FPGAs, etc., that constitute the control unit 202. Of course, the present invention is not limited to this, and it is also possible to configure the communication unit 206 and the antenna to cooperate to execute each of the processes shown in the flowcharts. When it is desired to clearly indicate the subject of the process, the functional unit described in FIG. 3 will be used as the subject.

[0048] The operation of the AP MLD 101 will be described with reference to Fig. 4. Each process shown in Fig. 4 is an excerpt of a series of processes from when the AP MLD 101 starts operating as an MLO until it starts operating in the EMLSR mode, which is the MLO mode. Note that when the control unit 202 of the AP MLD 101 determines that an operation setting that does not use the power saving mode is stored in the storage unit 201, it executes control of the normal mode (not shown) instead of the control shown in Fig. 4. In other words, when an operation setting that uses the power saving mode is stored in the storage unit 201, it executes each control shown in Fig. 4.

[0049] A brief explanation of the normal mode (not shown) will be given. The AP MLD 101 in the normal mode builds and maintains the two networks described above. It allows STAs such as the non-AP MLD 102 to connect to the AP MLD 101 in the EMLSR mode. For STAs connected to the AP MLD 101 in the EMLSR mode, the EMLSR link is enabled using the initial control frame as a trigger, as described above. Data communication of user data, etc. can be performed using the enabled EMLSR link. The AP MLD 101 in the normal mode provides data communication using multiple links simultaneously as appropriate for non-AP MLDs connected to the AP MLD 101 in the STR mode or NSTR mode.

[0050] Returning to the explanation of Fig. 4, the control when the operation setting using the power saving mode is performed will be explained. First, the MLO device search phase in which the STA searches for an AP to connect to, and the MLO setup phase in which the STA performs a multi-link connection to the AP found as a result of the search will be explained. In S400, the multi-link control unit 301 cooperates with the frame generation unit 305, the frame transmission / reception unit 306, the communication unit 206, and the antennas 207 to 208 to execute control to include information presenting an attempt to enable the EMLSR mode in a frame and transmit it. The frame transmitted in S400 is a frame transmitted in the MLO device search phase and the MLO setup phase.

[0051] More specifically, the AP MLD 101 includes information indicating that the EMLSR mode is to be enabled in a Beacon frame or a Probe Response frame. Hereinafter, the information indicating that the EMLSR mode is to be enabled is simply referred to as enablement information. Also, information indicating that the EMLSR mode, which will be described later, is to be disabled is simply referred to as disablement information.

[0052] The Beacon frame is a frame that the AP MLD 101 transmits periodically at a predetermined cycle (for example, 100 ms). The Probe Response frame is a frame that is transmitted as a response to a Probe Request frame received from a STA such as the non-AP MLD 102 when that frame is received. However, this is not limited to this, and the frame can also be configured to transmit information indicating that the EMLSR mode is to be enabled or disabled at any other timing or in any other frame during the search phase or connection phase of the connection destination.

[0053] Although details will be described later, when the search process in the search phase is completed in the opposing STA and connection processing to the AP MLD 101 is started, the AP 101 performs a Multi-Link Setup procedure.

[0054] The AP MLD 101 may include validation information in an Association Response frame or a Reassociation Response frame transmitted in the Multi-Link Setup procedure. These frames are response frames that store response information when an Association Request frame or a Reassociation Request frame is received from a STA such as the non-AP MLD 102.

[0055] Furthermore, the AP MLD 101 may transmit a frame including a UHR Operation element that controls the operation of a device compatible with the IEEE 802.11 UHR standard to a STA such as the non-AP MLD 102, and include activation information in the element.

[0056] A specific example of including activation information in the UHR Operation element will be described with reference to Fig. 5. The UHR Operation element is composed of fields 500 to 506. The UHR Operation element includes a UHR Operation Parameters field 503 and an EMLSR Control field 506. The UHR Operation element also includes the same type of information as the EHT Operation element defined in IEEE802.11be.

[0057] An Element ID field 500, a Length field 501, and an Element ID Extension field 502 each contain the same information as the fields of the same names defined in the IEEE 802.11be standard.

[0058] The UHR Operation Parameters field 503 includes an EMLSR Control Present subfield 515. Field 503 also includes information similar to the EHT Operation Parameters field defined in the IEEE 802.11be standard.

[0059] The Basic UHR-MCS and Nss Set field 504 contains information similar to the Basic EHT-MCS and Nss Set field defined in the IEEE802.11be standard. The UHR Operation Information field 505 contains information similar to the EHT Operation Information field. The EMLSR Control field 506 is a field that contains information for controlling the operation of a device related to the EMLSR mode. This field will be described in detail later.

[0060] The UHR Operation Parameters field 503 is composed of subfields 510 to 515. The UHR Operation Information Present subfield 510 includes information similar to that of the EHT Operation Information Present subfield defined in the IEEE 802.11be standard. The Disabled Subchannel Bitmap Present subfield 511 includes information similar to that of the subfield of the same name defined in the IEEE 802.11be standard. The UHR Default PE Duration subfield 512 includes information similar to that of the EHT Default PE Duration subfield defined in the IEEE 802.11be standard. The Group Addressed BU Indication Limit subfield 513 includes information similar to that of the subfield of the same name defined in the IEEE 802.11be standard. The Group Addressed BU Indication Exponent subfield 514 includes information similar to that of the subfield of the same name defined in the IEEE 802.11be standard. The EMLSR Control Present subfield 515 indicates whether the UHR Operation element includes the EMLSR Control field 506. This subfield is composed of 1 bit. If its value is 1, it means that the UHR Operation element includes the EMLSR Control field 506, while if its value is 0, it means that the UHR Operation element does not include the EMLSR Control field 506.

[0061] The EMLSR Control field 506 is present when the value of the EMLSR Control Present subfield 515 is 1, and is not present when the value is 0. This field is composed of subfields 520 and 521. The EMLSR Mode subfield 520 indicates whether the EMLSR mode is to be enabled. This subfield is composed of 1 bit. If the value is 1, it means that the EMLSR mode is to be enabled. On the other hand, if the value is 0, it means that the EMLSR mode is to be disabled. The EMLSR Link Bitmap subfield 521 indicates the link ID of the link to be used as the EMLSR link. This subfield is composed of 16 bits, and the i-th bit corresponds to the state of the link whose Link ID is i. For example, bit 0 corresponds to the state of the link whose Link ID is 0, bit 1 corresponds to the state of the link whose Link ID is 1, and so on.

[0062] Storing a 1 in the EMLSR Mode subfield 520 is an example of including enabling information in the frame, and storing a 0 in the EMLSR Mode subfield 520 is an example of including disabling information in the frame.

[0063] The AP MLD 101 that has transmitted the activation information receives information indicating whether to permit or deny the AP MLD from enabling the EMLSR mode as a response to the activation information from MLD devices such as the non-AP MLD 102. Hereinafter, information permitting the AP MLD to enable the EMLSR mode is referred to as permission information, and information denying the AP MLD from enabling the EMLSR mode is referred to as denial information.

[0064] This information can be included in a Probe Request frame, an Association Request frame, or a Reassociation Request frame transmitted by an MLD device such as the non-AP MLD 102.

[0065] Specifically, an MLD device such as the non-AP MLD 102 includes a Probe Request Multi-Link element in a Probe Request frame, which can be configured to include permission information or denial information.

[0066] FIG. 6 shows an example of a Probe Request Multi-Link element. The Probe Request Multi-Link element is composed of fields 600 to 605. The Probe Request Multi-Link element includes a Multi-link Control field 603 and a Common Info field 604. The fields 603 and 604 include the same information as the elements of the same name defined in the IEEE 802.11be standard except for some subfields. The Element ID field 600, the Length field 601, and the Element ID Extension field 602 each include the same information as the fields of the same name defined in the IEEE 802.11be standard except for some subfields in the Presence Bitmap subfield 612. Details of this field will be described later. The Common Info field 604 includes the same information as the fields of the same name defined in the IEEE 802.11be standard except for the EMLSR Control subfield 632. Details of this field will be described later. The Link Info field 605 contains information similar to the field of the same name defined in the IEEE 802.11be standard.

[0067] The Multi-link Control field 603 is made up of subfields 610 to 612. A Type subfield 610 and a Reserved subfield 611 each contain the same information as the subfields of the same name defined in the IEEE 802.11be standard.

[0068] The Presence Bitmap subfield 612 is composed of subfields 620 and 621. The AP MLD ID Present subfield 620 contains the same information as the subfield of the same name defined in the IEEE 802.11be standard. The EMLSR Control Present subfield 612 indicates whether the Probe Request Multi-Link element contains the EMLSR Control subfield 632 in its Common Info 604 field. This subfield is composed of 1 bit. If the value is 1, it means that the Probe Request Multi-Link element contains the EMLSR Control subfield 632. On the other hand, if the value is 0, it means that the Probe Request Multi-Link element does not contain the EMLSR Control subfield 632.

[0069] The Common Info field 604 is made up of subfields 630 to 632. The Common Info Length subfield 630 and the AP MLD ID subfield 631 each contain the same information as the subfields of the same name defined in the IEEE 802.11be standard.

[0070] The EMLSR Control subfield 632 is present if the EMLSR Control Present subfield 621 has a value of 1, and is absent if the value is 0. This subfield consists of the EMLSR Mode subfield 640 and the EMLSR Link Bitmap subfield 641. Setting the EMLSR Mode subfield 640 to 1 means that the AP MLD 101 is allowed to enable the EMLSR mode. On the other hand, setting the EMLSR Mode subfield 640 to 0 means that the AP MLD 101 is not allowed to enable the EMLSR mode.

[0071] Furthermore, when an MLD device responds with permission or denial information in an Association Request frame or a Reassociation Request frame, the information is included in a Basic Multi-Link element.

[0072] The information elements in this case will be described with reference to FIG. 7. FIG. 7 shows an example of the configuration of a Basic Multi-Link element included in an Association Request frame or a Reassociation Request frame transmitted by the non-AP MLD 102. The Basic Multi-Link element is composed of fields 700 to 705. Each field includes the same information as the element of the same name defined in the IEEE 802.11be standard, except for some subfields in the Multi-link Control field 703 and the Common Info field 704. The Element ID field 700, the Length field 701, and the Element ID Extension field 702 each include the same information as the field of the same name defined in the IEEE 802.11be standard. The Multi-link Control field 703 includes the same information as the field of the same name defined in the IEEE 802.11be standard, except for some subfields in the Presence Bitmap subfield 712. Details of this field will be described later. The Common Info field 704 includes the same information as the field of the same name defined in the IEEE 802.11be standard, except for the inclusion of the EMLSR Control subfield 739. Details of this field will be described later. Link Info field 705 contains the same information as the field of the same name defined in the IEEE 802.11be standard. Multi-link Control field 703 is composed of subfields 710 to 712. Type subfield 710 and Reserved subfield 711 each contain the same information as the subfield of the same name defined in the IEEE 802.11be standard.

[0073] The Presence Bitmap subfield 712 is composed of subfields 720 to 726 and an EMLSR Control Present subfield 621. The subfield 712 includes a Link ID Info Present subfield 720, a BSS Parameters Change Count Present subfield 721, a Medium Synchronization Delay Information Present subfield 722, an EML Capabilities Present subfield 723, an MLD Capabilities and Operations Present subfield 724, an AP MLD ID Present subfield 725, and an Extended MLD Capabilities And Operations Present subfield 726. Each of 720 to 726 includes information similar to the subfields of the same name defined in the IEEE 802.11be standard. The EMLSR Control Present subfield 621 is the same as that in the Probe Request Multi-Link element described above.

[0074] The Common Info field 704 is composed of subfields 730 to 738 and an EMLSR Control subfield 632. The field 704 includes a Common Info Length subfield 730, an MLD MAC Address subfield 731, a Link ID Info subfield 732, a BSS Parameters Change Count subfield 733, a Medium Synchronization Delay Information subfield 734, an EML Capabilities subfield 735, an MLD Capabilities and Operations subfield 736, an AP MLD ID subfield 737, and an Extended MLD Capabilities and Operations subfield 738. Each of the fields 730 to 737 includes information similar to the subfields of the same name defined in the IEEE 802.11be standard. The EMLSR Control subfield 632 is the same as that in the Probe Request Multi-Link element described above. That is, the Basic Multi-Link element also includes the EMLSR Mode subfield 640 and the EMLSR Link Bitmap subfield 641 described above.

[0075] When the non-AP MLD 102 transmits permission information, it stores 1 in the EMLSR Mode subfield of the UHR Operation element, whereas when it transmits refusal information, it stores 0 in the EMLSR Mode subfield of the UHR Operation element.

[0076] Returning to the explanation of Figure 4, the AP MLD 101 and non-AP MLD 102 execute the multi-link setup procedure by exchanging frames containing information about the multi-link communication described in Figures 5 to 7. In other words, they exchange requests and acceptability in MLO, such as which link to use in multi-link communication and in which mode to operate. Then, they establish multi-link communication in the agreed-upon operating mode and with the agreed-upon link.

[0077] In S401, the control unit 301 judges whether the multi-link setup procedure has been normally completed. If it is judged that the multi-link setup procedure has been normally completed, the process proceeds to S402, and if it is judged that the multi-link setup procedure has not been normally completed, the exchange of frames for the setup procedures continues.

[0078] In S402, the control unit 301 determines whether or not a frame including permission information has been received during the exchange with the AP MLD 102 with which Multi-Link communication has been established, as shown in the procedure described above.

[0079] If it is determined that a frame including permission information has been received, the process proceeds to S403. On the other hand, if it is determined that a frame including permission information has not been received (i.e., if it is determined that a frame including refusal information has been received, or if the response frame does not include an information element corresponding to refusal information or permission information), the process proceeds to S404.

[0080] In S403, the control unit 301 starts the EMLSR mode in cooperation with each unit such as the communication unit 206 and the antennas 207 to 208. Specific control after starting the EMLSR mode will be described later with reference to the flowchart in FIG.

[0081] On the other hand, in S404, the control unit 301 starts operation in the normal mode in cooperation with each unit such as the communication unit 206 and the antennas 207 to 208. The operation in the normal mode may be performed by performing the data communication control described at the beginning of FIG.

[0082] Next, the search phase processing and MLO setup phase processing executed by the non-AP MLD 102 side will be explained using Fig. 8. This operation is executed when the non-AP MLD 102 starts the search phase processing for searching for AP MLDs that support MLO. Note that the processes shown in Fig. 8 and Fig. 10 are excerpts of the processing when the non-AP MLD 102 determines the MLO mode and performs Multi-Link communication with the AP MLD 101.

[0083] The non-AP MLD 102 searches for surrounding APs by scanning Beacon frames emitted by the surrounding APs, transmitting Probe Request frames to the surrounding APs, and receiving Probe Response frames.Then, by exchanging information elements related to Multi-Link described in Figures 5 to 7, the non-AP MLD 102 discovers AP MLDs that support MLO and establishes a connection with the discovered AP MLD.

[0084] In S800, the control unit 301 determines whether or not it has received a response frame to the search or a frame for MLO setup from the AP MLD 101, the response frame including information (activation information) indicating that the EMLSR mode is to be activated.

[0085] If it is determined that a frame including validation information has been received, the process proceeds to S801. On the other hand, if it is determined that a frame including validation information has not been received (i.e., if a frame including invalidation information has been received, or if it is determined that a frame including neither invalidation information nor validation information has been received), the process proceeds to S802.

[0086] In S801, the control unit 301 decides whether or not to permit the EMLSR mode to be enabled. At this time, the non-AP MLD 101 can be configured to make the decision based on information previously stored in the storage unit 201. Subsequently, in S802, the control unit 301 cooperates with each unit such as the generation unit 305, the transmission / reception unit 306, the communication unit 206, and the antennas 207 to 208 to transmit a search frame and / or a frame for setup including information corresponding to the decision result. Specifically, when the non-AP MLD 102 decides to permit the EMLSR mode to be enabled, it transmits the frame including permission information. Also, when the non-AP MLD 102 decides not to permit the EMLSR mode to be enabled, it transmits the frame including refusal information.

[0087] In S803, the control unit 301 judges whether the multilink setup procedure has been completed normally. If it is judged that the multilink setup procedure has been completed normally, the process proceeds to S804, and if it is judged that the multilink setup procedure has not been completed normally, the process proceeds to S800 to continue exchanging frames for various procedures such as search and setup.

[0088] In S804, the control unit 301 judges whether or not the AP MLD 101 has presented permission to enable the EMLSR mode in procedures such as discovery and setup. If the control unit 301 judges that the AP has presented permission to enable the EMLSR mode, the process proceeds to S805. On the other hand, if the control unit 301 does not judge that the AP has presented permission to enable the EMLSR mode (i.e., if refusal information has been transmitted or if enable / disable information is not included in the frame received from the AP), the process proceeds to S806.

[0089] In S805, the control unit 301 starts operating in the EMLSR mode in cooperation with the generation unit 305, the transmission / reception unit 306, the communication unit 206, the antennas 207 to 208, etc. The details of this operation will be described later with reference to FIG. 10. On the other hand, in S806, the control unit 301 starts control to communicate with the AP in the normal mode (such as the STR mode) in cooperation with the generation unit 305, the transmission / reception unit 306, the communication unit 206, the antennas 207 to 208, etc. In the normal mode, it is assumed that general Multi-Link communication such as simultaneous communication of data using a plurality of established link pairs is executed.

[0090] <Communication Control in EMLSR Mode> Subsequently, the communication control after starting the operation in the EMLSR mode will be described with reference to FIGS. 9 and 10.

[0091] First, the control after starting the operation in the EMLSR mode in the AP MLD101 will be described with reference to FIG. 9. In S900, the control unit 301 of the AP MLD101 cooperates with the communication unit 206 to listen to a plurality of EMLSR links and determines whether a frame of a predetermined type has been received from the EMLSR non-AP MLD. The EMLSR non-AP MLD means a non-AP MLD such as the non-AP MLD102 that has established a connection with the AP MLD101 and is operating in the EMLSR mode.

[0092] Note that the EMLSR links listened to by the AP MLD101 in S900 are the links presented in the procedure described in FIG. 4. That is, they are the links presented in the EMLSR Link Bitmap subfield 521 of the UHR Operation element by the AP MLD101 to the EMLSR non-AP MLD. In the present embodiment, it will be described assuming that the link 103 and the link 104 described in FIG. 1 are presented as the EMLSR links.

[0093] At this time, the AP MLD 101 uses antennas 207 and 208 to listen for received signals on both the channel corresponding to link 103 and the channel corresponding to link 104 .

[0094] The predetermined type of frame is a frame that causes an operation to execute data exchange with the EMLSR mode temporarily released, or an initial control frame for executing data exchange while maintaining the EMLSR mode. Hereinafter, a frame that causes an operation to execute data exchange with the EMLSR mode temporarily released is called an EMLSR mode temporary release frame.

[0095] These frames may be newly defined MAC (Media Access Control) frames to indicate temporary release. The initial control frame may be a newly defined MAC frame for the purpose of transmitting a request from the STA to the AP to start communication on the EMLSR link. These frames may be management frames or data frames.

[0096] Furthermore, an existing specific type of control frame or data frame may be regarded as an EMLSR mode temporary release frame when operating in the EMLSR mode.

[0097] For example, an RTS frame, which is a frame for requesting a transmission opportunity by non-AP MLD, is an example of an EMLSR mode temporary release frame, and an NDP frame, which is a data frame that does not contain any substantial data, is an example of an EMLSR mode temporary release frame.

[0098] Note that the EMLSR mode temporary release frame and the initial control frame are defined as different types of MAC frames, or the same type of MAC frames with different values ​​of fields within the frame.

[0099] Also, an EML Operating Mode Notification frame in which the value of the EMLSR Mode subfield of the EML Control field is 0 is an example of an EMLSR mode temporary release frame.

[0100] Next, in S901, the control unit 301 determines whether the frame received in S900 is an EMLSR mode temporary release frame. If the frame received in S900 is an EMLSR mode temporary release frame, the process proceeds to S902. If the frame received in S900 is not an EMLSR mode temporary release frame (i.e., an initial control frame), the process proceeds to S905.

[0101] In S902, the control unit 301 temporarily releases the EMLSR mode and transitions to the normal mode. Then, an exchange is performed with the non-AP MLD that is the source of the EMLSR mode temporary release frame to reconfigure the MLO operation mode. Then, the MLO operation mode with the non-AP MLD is switched to a communication mode that utilizes multiple links, such as STR mode or NSTR mode. Then, data communication is performed that utilizes multiple links. When the data communication is completed, the AP MLD 101 re-transitions to the EMLSR mode. When performing the re-transition, the AP MLD 101 may notify the non-AP MLD connected to the AP MLD 101 of activation information. Alternatively, the AP MLD 101 may automatically re-transition to the EMLSR mode upon completion of the data communication. When the re-transition is completed, the control unit 301 advances the process to S906. In this S902, data communication can be performed using multiple links simultaneously. Therefore, data exchange can be performed with a higher throughput or a smaller transmission delay than an operation in which data communication is performed via one EMLSR link while maintaining the EMLSR mode described later.

[0102] Next, control in the case where it is not determined that a frame of a predetermined type has been received will be described. The control unit 301 determines whether or not there is data to be communicated with the EMLSR non-AP MLD. For example, when data to be transmitted to the EMLSR non-AP MLD occurs, the control unit 301 determines that there is data to be communicated with the EMLSR non-AP MLD. The data is, for example, data addressed to the EMLSR non-AP MLD received from an external network such as the Internet via a wired LAN or the like. Note that the data may also be data addressed to the EMLSR non-AP MLD received from a communication device or the like connected to the wired LAN.

[0103] If the control unit 301 determines that there is data to be communicated with the EMLSR non-AP MLD, it proceeds to S904; if it does not determine that there is data to be communicated with the EMLSR non-AP MLD, it proceeds to S906.

[0104] In S904, the control unit 301 cooperates with the generation unit 305, the transmission / reception unit 306, the communication unit 206, the antennas 207 to 208, etc. to transmit an initial control frame to the EMLSR non-AP MLD that is the communication destination of the data. More specifically, the AP MLD 101 transmits an initial control frame defined in the IEEE802.11be standard to the EMLSR non-AP MLD that is the communication destination of the EMLSR data via either the link 103 or the link 104. When the transmission is completed, the process proceeds to S905. The control unit 301 may determine which link to use to transmit the initial control frame based on the communication congestion status, etc.

[0105] In S905, the control unit 301 cooperates with the generation unit 305, the transmission / reception unit 306, the communication unit 206, the antennas 207-208, etc. to enable one link that has transmitted or received the initial control frame so that normal data communication can be performed. Then, data exchange with non-AP MLD is performed on the enabled link. That is, data exchange is performed on the EMLSR link enabled for communication while maintaining the EMLSR mode.

[0106] After receiving the EMLSR mode temporary release frame or the initial control frame, the AP MLD 101 may transmit a response frame to the sender of the frame before executing data exchange. A CTS (Clear To Send) frame or an ACK frame may be used as the response frame. Also, when the AP MLD 101 transmits an initial control frame to transmit a data frame to a non-AP MLD, the AP MLD 101 may perform control equivalent to CTS. In this case, the AP MLD 101 may transmit a CTS-to-self frame on the enabled EMLSR link before executing data exchange.

[0107] Also, the EMLSR mode temporary release frame or the initial control frame and the subsequent data exchange may be performed in one frame exchange sequence. Alternatively, each may be included in a different frame exchange sequence. In this embodiment, data exchange means a process of transmitting a data frame from another device to one device, and a series of exchanges of transmitting a frame including information from one device to the other device that the data frame has been received. The frame including information from one device to the other device that the data frame has been received is, for example, an ACK frame or a Block ACK frame.

[0108] In S906, the control unit 301 judges whether to end the operation in the EMLSR mode. Specifically, when it is judged that the AP MLD 101 has received a setting change operation to disable the power saving mode, it judges to end the operation in the EMLSR mode. In addition, when the data communication amount with the non-AP MLD is increasing, or when it is inferred that the data communication amount is increasing based on the past communication tendency, it also judges to end the operation in the EMLSR mode. In addition, when the number of STAs connected to the non-AP MLD exceeds a predetermined value, it may be judged to end the operation in the EMLSR mode. In addition, when the data communication amount is not increasing, the control unit 301 judges not to end the operation in the EMLSR mode.

[0109] If the control unit 301 determines not to end the operation in the EMLSR mode, it advances the process to S900. On the other hand, if the control unit 301 determines to end the operation in the EMLSR mode, it transmits a frame notifying that effect. This frame may be a frame including information (disabling information) indicating that the EMLSR mode is to be disabled. It may also be an EML Operating Mode Notification frame in which the value of the EMLSR Mode subfield of the EML Control field is 0. When the AP MLD 101 ends the operation in the EMLSR mode, it starts operating as a normal MLO capable of simultaneous communication in the network corresponding to the link 103 and the network corresponding to the link 104.

[0110] Finally, the control after starting operation in the EMLSR mode in the non-AP MLD 102 will be described with reference to FIG.

[0111] In S1000, control unit 301 of non-AP MLD 102 determines whether data to be transmitted has occurred to AP MLD 101. If it is determined that data to be transmitted has occurred, the process proceeds to S1002, and if it is not determined that data to be transmitted has occurred, the process proceeds to S1006.

[0112] In S1006, the control unit 301 cooperates with each unit to determine whether or not an initial control frame has been received from the AP MLD 101. If it is determined that an initial control frame has been received from the AP MLD 101, the process proceeds to S1004, and if it is not determined that an initial control frame has been received, the process proceeds to S1005.

[0113] In S1002, the control unit 301 determines whether to transition to a normal Multi-Link mode such as the STR mode and perform communication in order to exchange data.

[0114] When the non-AP MLD 102 determines that a situation has arisen in which data exchange should be performed using multiple links, it determines that communication should be performed by transitioning to the normal Multi-Link mode. More specifically, when the control unit 301 determines that data that should be exchanged at high throughput or low delay has occurred, it determines that communication should be performed by transitioning to the normal Multi-Link mode. When the control unit 301 determines that communication should be performed by transitioning to the normal Multi-Link mode, it advances the process to S1003, and when it does not determine that communication should be performed by transitioning to the normal Multi-Link mode, it advances the process to S1004.

[0115] In S1003, the control unit 301 cooperates with each unit to transmit the above-mentioned EMLSR mode temporary release frame to the AP MLD 101. Then, the control unit 301 transitions to a normal Multi-Link mode such as STR mode, and executes data exchange with the AP MLD 101. When the data exchange is completed, the control unit 301 again negotiates the mode with the AP MLD 101, and re-transitions to the EMLSR mode. Alternatively, the control unit 301 automatically re-transitions to the EMLSR mode upon completion of the data exchange. When the re-transition is completed, the control unit 301 advances the process to S1005.

[0116] On the other hand, in S1004, the control unit 301 cooperates with each unit to transmit an initial control frame to the AP MLD 101. In addition, in the case where an initial control frame is received from the AP MLD in S1006, the process of transmitting the initial control frame to the AP MLD 101 is omitted. Next, the control unit 301 cooperates with each unit to enable one link that has transmitted or received the initial control frame so that normal data communication can be performed. Then, data exchange with the AP MLD 101 is performed through the enabled link. That is, data exchange is performed through the EMLSR link enabled for communication while maintaining the EMLSR mode. When the control unit 301 determines that a series of data exchanges is completed, it advances the process to S1005.

[0117] The control unit 301 transmits the EMLSR mode temporary release frame and the initial control frame through one of the EMLSR links. The control unit 301 can appropriately determine which EMLSR link to use to transmit the frame, taking into account the channel usage status, etc.

[0118] As described above, the non-AP MLD 102 can be configured to transmit an EMLSR mode temporary release frame or an initial control frame, and then perform actual data exchange after receiving a response frame for that. In this case, if the non-AP MLD 102 does not receive a response frame from the AP MLD 101, it may not perform data exchange and may resend the EMLSR mode temporary release frame or the initial control frame. Also, if the non-AP MLD 102 transmits an EMLSR mode temporary release frame and does not receive a response frame for that, it may be controlled so that the AP MLD 101 is considered to be operating in EMLSR mode. In this case, the non-AP MLD 102 may attempt data exchange only over the EMLSR link that transmitted the EMLSR mode temporary release frame.

[0119] Returning to the explanation of FIG. 10, in S1005, the control unit 301 judges whether to terminate the EMLSR mode. If it is judged that the EMLSR mode is to be terminated, the EMLSR mode is terminated and transition is made to a normal Multi-Link mode such as the STR mode. On the other hand, if it is judged that the EMLSR mode is not to be terminated, the process proceeds to S1000. Specifically, the control unit 301 judges that the operation in the EMLSR mode is to be terminated when the data communication amount with the AP MLD 101 is on the increase, or when it is inferred that the data communication amount is on the increase based on the past communication tendency, etc. Also, if the data communication amount is not on the increase, etc., the control unit 301 judges that the operation in the EMLSR mode is not to be terminated, and the process proceeds to S1000.

[0120] The above-described processing makes it possible to quickly respond to changes in the throughput or transmission delay amount required by non-AP MLD while operating AP MLD in a power-saving manner.

[0121] The effect of this embodiment will be described with reference to Fig. 11. Fig. 11 is a schematic diagram for explaining the relationship between the EMLSR mode and a normal mode such as the STR mode, and power consumption in this embodiment.

[0122] The AP MLD 101 operates in the EMLSR mode during a period 1100 before transmitting a response frame 1111 to the EMLSR mode temporary release frame 1110 .

[0123] During operation in EMLSR mode, the AP MLD 101 waits to receive an EMLSR mode temporary release frame or an initial control frame on multiple EMLSR links. However, the AP MLD 101 can actually receive and decode data frames on only one link. Also, the AP MLD 101 can transmit frames on only one link. During operation in EMLSR mode, the AP MLD 101 waits to receive frames on multiple EMLSR links. At this time, the control unit 301 cooperates with each unit to control the supply of power to a circuit for listening to multiple channels corresponding to multiple EMLSR links and a circuit for transmitting and receiving frames on one link. At this time, the control unit 301 stops the supply of power and / or a clock signal to a circuit that is necessary for simultaneously exchanging frames on two links, but to which there is no problem if the power supply is stopped in EMLSR mode. For example, the control unit 301 controls so as not to supply power and / or a clock signal to the circuit 2 illustrated in FIG. 12. This makes it possible to reduce the power consumption required to maintain circuits that are necessary to simultaneously exchange frames over two links but do not need to operate in EMLSR mode, such as circuit 2 shown in Fig. 12. This allows for a reduction in power consumption compared to the period during which normal multi-link operation is performed.

[0124] Next, the non-AP MLD 102 transmits an EMLSR mode temporary release frame 1110 to the AP MLD 101 via one of the EMLSR links.

[0125] When the AP MLD 101 receives an EMLSR mode temporary release frame 1110 from the non-AP MLD 102, it transmits a response frame 1111 to the non-AP MLD 102 over one of the EMLSR links. Then, it releases the EMLSR mode and starts normal multi-link operation. At this time, as shown in Fig. 12 for normal multi-link operation, power is supplied to the circuits required for simultaneously exchanging frames over two links, and data is actually exchanged, so power consumption increases.

[0126] During period 1101, the AP MLD 101 exchanges data with the non-AP MLD 102 over multiple links using a normal mode such as STR mode or NSTR mode. In the data exchange procedure, the AP MLD 101 receives a data frame 1112 and transmits a response frame (here, an ACK frame 1113) to the non-AP MLD 102. When a series of data exchanges is completed, the AP MLD 101 transitions back to the EMLSR mode (period 1102).

[0127] 11 and 12, it is possible to introduce the EMLSR mode into the AP MLD 101 and quickly transition from the EMLSR mode to a normal mode such as the STR mode or NSTR mode. Therefore, it is possible to quickly respond to changes in the throughput or transmission delay amount required by the non-AP MLD while enabling power saving operation in the AP MLD 101.

[0128] <Variation 1> The operations of S402 and S404 in FIG. 4 in the AP MLD 101 described in the above embodiment can be omitted. In this case, the AP MLD 101 starts operation in the EMLSR mode regardless of whether or not it has received a frame including information indicating that the EMLSR mode is permitted to be enabled from the non-AP MLD 102. In addition, in this case, the non-AP MLD 102 can omit the operations of S801, S803, and S805. In this case, the non-AP MLD 102 determines that the AP MLD 101 operates in the EMLSR mode based on the reception of a frame including information indicating that the EMLSR mode is to be enabled from the AP MLD 101. Then, when the non-AP MLD 102 determines that the AP MLD 101 operates in the EMLSR mode, it may execute the process of S804.

[0129] <Variation 2> In the above embodiment, the case where the power supply to the circuit that is necessary for simultaneously exchanging frames over two links but that can be stopped without causing any problem in the EMLSR mode is exemplified. However, the power control method is not limited to this, and it is also possible to configure the device to perform more proactive power saving control.

[0130] Here, the power state corresponding to the EMLSR mode is called the first power state, and the power state corresponding to the normal mode is called the second power state. In order to further reduce the power consumption in the first power state, a general-purpose hardware processor such as a CPU constituting the control unit 202 can be controlled to operate in a power saving mode. This will be specifically described with reference to FIG. 13.

[0131] In the second modification, it is assumed that the control unit 202 is configured with a general-purpose hardware processor such as a CPU, and executes a control program to control the communication unit 206 such as a wireless chip. That is, the control unit 202 includes a general-purpose hardware processor that cooperates with the communication chip to control communication.

[0132] The instruction set architecture of this general-purpose hardware processor can be x64 architecture, ARM architecture, RISC-V architecture, etc. It may also be x86 architecture or MIPS architecture.

[0133] When the control unit 301 of the AP MLD 101 transitions the power state of the AP MLD 101 to the first power state, the control unit 301 changes the operation mode of the general-purpose hardware processor so that the AP MLD 101 operates in a power saving state.

[0134] The change in the operation mode may have the effect of causing clock gating and / or power gating within the general-purpose hardware processor. The operation mode may also be changed so that a general-purpose memory such as a DRAM (Dynamic Random Access Memory) operates in a power-saving state.

[0135] The effect of this will be explained as follows. When designing the AP MLD 101, a general-purpose hardware processor and general-purpose memory are appropriately adopted that have the hardware capacity to process data without problems, taking into consideration the load of data processing in normal modes such as the STR mode and NSTR mode.

[0136] Therefore, compared to the normal mode, there is an abundance of processing capacity during periods 1100 and 1102 when the processing load is expected to be low. In this embodiment, the processing capacity of the general-purpose hardware processor and general-purpose memory can be intentionally lowered during periods 1100 and 1102 when the load is low, thereby reducing power consumption, thereby achieving further power saving. Therefore, the power consumption in the EMLSR mode operation can be reduced more than in the normal mode operation such as the STR or NSTR mode.

[0137] It is also possible to configure the first power state and the second power state to be switched for each state constituting the EMLSR mode. Specifically, the power state can be made different between the state of listening to the EMLSR link and the communication state of actually performing communication using the EMLSR link. For example, in this case, when listening to a packet in the EMLSR mode, the first power state can be adopted in which the general-purpose hardware processor and the general-purpose memory are also operated in a power-saving state. On the other hand, in the communication state of actually performing data communication using the EMLSR link, the second power state can be adopted in which the general-purpose hardware processor and the general-purpose memory are also operated in a normal mode.

[0138] <Modification 3> In the above embodiment, a case has been described in which the non-AP MLD 102 is configured to start operating in EMLSR mode in S804. However, the non-AP MLD 102 may simply start appropriate control so as to be able to communicate with the AP MLD 101 that has started operating in EMLSR mode, without starting operation in EMLSR mode. In other words, the non-AP MLD itself may be configured not to transition to EMLSR mode.

[0139] In this case, each process in FIG. 10 used to explain the details of step S804 may be modified as follows. First, the process in FIG. 10 is started by starting the process of step S804 in this modified example. In S1006, the control unit 301 determines whether or not any frame has been received from the AP MLD 101 in cooperation with each unit, not limited to an initial control frame. At this time, the AP MLD 101 operates in EMLSR mode and transmits frames only through one link, so the non-AP MLD 102 receives frames only through one link. If the non-AP MLD 102 determines that it has received a frame from the AP MLD 101, it advances the process to S1004, and if it does not determine that it has received a frame, it advances the process to S1000. Also, in S1004, the control unit 301 transmits an initial control frame to the AP MLD 101 in cooperation with each unit. In addition, in the case where some frame is received from the AP MLD in S1006, the process of transmitting an initial control frame to the AP MLD 101 is omitted. Next, the control unit 301 cooperates with each unit to execute data exchange with the AP MLD 101 on one link that transmitted the initial control frame or one link that received some frame. That is, data exchange is performed while maintaining a state corresponding to the AP MLD 101 operating in the EMLSR mode. When the control unit 301 determines that a series of data exchanges is completed, it advances the process to S1000. In addition, the non-AP MLD 102 of this modified example, which does not start operating in the EMSLR mode, can simply repeat the receiving operation of the modified example without making the determination of S1005.

[0140] (Other embodiment 1) The disclosure of this embodiment also includes the following configuration.

[0141] (Configuration 1) An access point device that performs wireless communication based on the IEEE 802.11 standard, a determination means for determining whether a frame of a predetermined type is received from a station device connected to the access point device when the access point device is operating in an enhanced multi-link single radio (EMLSR) mode; a communication control means for releasing the EMLSR mode and performing data communication with the station device when the determining means determines that the frame of the predetermined type has been received; a transition means for transitioning to the EMLSR mode after data communication is performed by the communication control means; A communication device comprising:

[0142] (Configuration 2) 2. The communication device according to claim 1, wherein the predetermined type of frame is an RTS (Request To Send) frame.

[0143] (Configuration 3) 2. The communication device according to claim 1, wherein the predetermined type of frame is a Null data PPDU (NDP) frame.

[0144] (Configuration 4) 2. The communication device according to claim 1, wherein the predetermined type of frame is an enhanced multi-link (EML) Operating Mode Notification frame.

[0145] (Configuration 5) A station device that performs wireless communication based on the IEEE 802.11 standard, a communication control means for transmitting a predetermined type of frame to an access point device to which the station device is connected, the access point device operating in an EMLSR (enhanced multi-link single radio) mode; the communication control means transmits the frame of the predetermined type, and then performs data communication with the access point device that has released the EMLSR mode using the reception of the frame of the predetermined type as a trigger; A station device comprising:

[0146] (Configuration 6) 6. The station device according to configuration 5, wherein the predetermined type of frame is an RTS (Request To Send) frame.

[0147] (Configuration 7) 6. The station device according to configuration 5, wherein the predetermined type of frame is an NDP (Null data PPDU) frame.

[0148] (Configuration 8) 6. The station device according to configuration 5, wherein the predetermined type of frame is an enhanced multi-link (EML) Operating Mode Notification frame.

[0149] (Configuration 9) An access point device that performs wireless communication based on the IEEE 802.11 standard, a determination means for determining whether a frame of a predetermined type is received from a station device connected to the access point device when the access point device is operating in a first power state and in an enhanced multi-link single radio (EMLSR) mode; a communication control means for transitioning to a second power state and performing data communication with the station device after the determination means determines that the frame of the predetermined type has been received; a control means for controlling a power state of the communication device to transition from the second power state to the first power state after the data communication is performed by the communication control means; the first power state is a power state consuming less power than the second power state; An access point device characterized in that, when the control means transitions the power state of the communication device to the first power state, it changes the operating mode of a general-purpose hardware processor that works in cooperation with a communication chip to control communications so that the general-purpose hardware processor operates in a power-saving state.

[0150] (Configuration 10) The access point device according to configuration 9, wherein the instruction set architecture of the general-purpose hardware processor is any one of an x64 architecture, an ARM architecture, and a RISC-V architecture.

[0151] (Configuration 11) 11. The access point device according to configuration 9 or 10, wherein the change in the operation mode causes clock gating and / or power gating within the general-purpose hardware processor.

[0152] (Configuration 12) 12. The access point apparatus according to any one of configurations 9 to 11, wherein the predetermined type of frame is an initial control frame.

[0153] (Configuration 13) A method for controlling an access point device that performs wireless communication based on the IEEE 802.11 standard, comprising: a determination step of determining whether a frame of a predetermined type is received from a station device connected to the access point device when the access point device is operating in an enhanced multi-link single radio (EMLSR) mode; a communication control step of releasing the EMLSR mode and performing data communication with the station device when it is determined in the determination step that the frame of the predetermined type has been received; a transition step of transitioning to the EMLSR mode after data communication is performed in the communication control step; A control method comprising the steps of:

[0154] (Configuration 14) A method for controlling a station device that performs wireless communication based on the IEEE 802.11 standard, comprising: a transmission control step of transmitting a predetermined type of frame to an access point device to which the station device is connected, the access point device being operated in an enhanced multi-link single radio (EMLSR) mode; a communication control means for performing data communication with the access point device which has released the EMLSR mode after transmitting the frame of the predetermined type; and A control method comprising the steps of:

[0155] (Configuration 15) 15. A program for causing a computer to execute the control method according to configuration 13 or 14.

[0156] (Other embodiment 2) The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0157] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0158] 101 AP MLD 102 non-AP MLD 206 Communications Department

Claims

1. An access point device that performs wireless communication based on the IEEE 802.11 standard, a determination means for determining whether a frame of a predetermined type has been received from a station device connected to the access point device when the access point device is operating in an enhanced multi-link single radio (EMLSR) mode; a communication control means for releasing the EMLSR mode and performing data communication with the station device when the determining means determines that the frame of the predetermined type has been received; a transition means for transitioning to the EMLSR mode after data communication is performed by the communication control means; A communication device comprising:

2. 2. The communication device according to claim 1, wherein the predetermined type of frame is an RTS (Request To Send) frame.

3. 2. The communication device according to claim 1, wherein the predetermined type of frame is a Null Data PPDU (NDP) frame.

4. 2. The communication device according to claim 1, wherein the predetermined type of frame is an enhanced multi-link (EML) Operating Mode Notification frame.

5. A station device that performs wireless communication based on the IEEE 802.11 standard, a communication control means for transmitting a predetermined type of frame to an access point device to which the station device is connected, the access point device operating in an enhanced multi-link single radio (EMLSR) mode; a communication control means for performing data communication with the access point device which has released the EMLSR mode after transmitting the frame of the predetermined type, triggered by reception of the frame of the predetermined type; A station device comprising:

6. 6. The station device according to claim 5, wherein the predetermined type of frame is an RTS (Request To Send) frame.

7. 6. The station device according to claim 5, wherein the predetermined type of frame is a Null Data PPDU (NDP) frame.

8. 6. The station device according to claim 5, wherein the predetermined type of frame is an enhanced multi-link (EML) Operating Mode Notification frame.

9. An access point device that performs wireless communication based on the IEEE 802.11 standard, a determination means for determining whether a frame of a predetermined type is received from a station device connected to the access point device when the access point device is operating in a first power state and in an enhanced multi-link single radio (EMLSR) mode; a communication control means for transitioning to a second power state and performing data communication with the station device after the determination means determines that the frame of the predetermined type has been received; a control means for controlling a power state of the communication device to transition from the second power state to the first power state after the data communication is performed by the communication control means; the first power state is a power state consuming less power than the second power state; The access point device is characterized in that, when the control means transitions the power state of the communication device to the first power state, it changes the operating mode of a general-purpose hardware processor that works in cooperation with a communication chip to control communications so that the general-purpose hardware processor operates in a power-saving state.

10. 10. The access point device according to claim 9, wherein the instruction set architecture of the general-purpose hardware processor is any one of an x64 architecture, an ARM architecture, and a RISC-V architecture.

11. 11. The access point device according to claim 10, wherein the change in the operation mode causes clock gating and / or power gating within the general-purpose hardware processor.

12. 12. The access point device according to claim 9, wherein the predetermined type of frame is an initial control frame.

13. A method for controlling an access point device that performs wireless communication based on the IEEE 802.11 standard, comprising: a determination step of determining whether a frame of a predetermined type has been received from a station device connected to the access point device when the access point device is operating in an enhanced multi-link single radio (EMLSR) mode; a communication control step of releasing the EMLSR mode and performing data communication with the station device when it is determined in the determination step that the frame of the predetermined type has been received; a transition step of transitioning to the EMLSR mode after data communication is performed in the communication control step; A control method comprising the steps of:

14. A method for controlling a station device that performs wireless communication based on the IEEE 802.11 standard, comprising: a transmission control step of transmitting a predetermined type of frame to an access point device to which the station device is connected, the access point device operating in an enhanced multi-link single radio (EMLSR) mode; a communication control means for performing data communication with the access point device which has released the EMLSR mode after transmitting the frame of the predetermined type, using the reception of the frame of the predetermined type as a trigger; A control method comprising the steps of:

15. A program for causing a computer to execute the control method according to claim 13 or 14.

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