Communication apparatus, ap mld, control method, and program

Abstract

To provide a concrete mechanism for more positively reducing power consumption in a standby state.SOLUTION: A communication apparatus functioning as an access point that performs wireless communication conforming to the IEEE802. 11 standard series changes, in a case where the access point is operated in a specific power saving mode in which power consumption is lower than that in a normal mode, an operation in the specific power saving mode to an operation in the normal mode in accordance with reception of a connection request from a station that is not of a specific type. The specific power saving mode is a mode for waiting for communication from a station in a state in which at least two or more conditions of the number of communication links, the bandwidth, and the spatial stream are changed to low power consumption conditions in which power consumption is estimated to be smaller than that in the normal mode.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present invention relates to a communication device that functions as an access point and communicates data, and to an AP MLD. [Background technology]

[0002] In recent years, the increase in the amount of data being communicated has led to the development of communication technologies such as wireless LANs (Local Area Networks). 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] Technologies that utilize sleep and intermittent operation, etc., to reduce the power consumption of communication devices are also being considered. Patent Document 1 describes a procedure for achieving power saving in STAs by having an AP (Access Point) and a STA (Station) agree in advance on the wake-up times of the devices, communicating during the wake-up times, and reducing the power consumption of the STAs at other times.

[0004] The IEEE802.11be standard, which will be the successor to IEEE802.11ax, is currently being developed, and the UHR (Ultra High Reliability) Task Group is also currently studying the specifications for the IEEE802.11bn standard, which will be the successor to IEEE802.11be. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2016-511600 Summary of the Invention [Problem to be solved by the invention]

[0006] The 802.11be standard attempts to improve communication rates compared to previous standards. It also incorporates a multi-link operation (MLO) function that uses multiple communication links for high-speed data transmission and redundant transmission. Communication devices using new functions such as MLO may receive data over multiple links, multiple spatial streams, wide bandwidths, and high MCS (Modulation and Scheme). Therefore, even in idle states waiting for reception, it is generally necessary to control the signal receiving circuitry and antennas so that all signal patterns can be received. These key features of the standard are certainly useful in terms of faster communication speeds and higher reliability, contributing to an improved user experience. However, there is a problem in that the power required for proper operation of communication devices is increasing year by year. The power consumption of access points, in particular, is reaching non-negligible levels.

[0007] The present invention has been made in consideration of at least one of the above-mentioned problems. One aspect of the present invention aims to provide a mechanism for more actively reducing power consumption at an access point. Another aspect of the present invention aims to provide a mechanism for switching whether or not to more actively reduce power consumption at an access point, taking into account whether a legacy terminal is participating. [Means for solving the problem]

[0008] One aspect of the present invention provides a communication device that functions as an access point for wireless communication in accordance with the IEEE 802.11 standard series, and has a change means for changing operation from the specific power saving mode to the normal mode when the access point is operating in a specific power saving mode that consumes less power than a normal mode, upon receiving a connection request from a station that is not of a specific type, and the specific power saving mode is a mode in which at least two or more conditions of the number of communication links, bandwidth, and spatial streams are changed to low power consumption conditions that are estimated to consume less power than the normal mode, in order to reduce the amount of power consumption when waiting for communication compared to the power consumption when waiting for communication in the normal mode, and waits for communication from a station.

[0009] Another aspect of the present invention is an AP MLD (Multi-Link Device) having two or more Affiliated APs (Access Points), and is characterized in that it has a provision means for providing a network to surrounding stations by configuring one or more first-type Affiliated APs to support a specific power-saving mode that consumes less power than a normal mode, and configuring one or more second-type Affiliated APs not to support the specific power-saving mode. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to provide a mechanism for more actively reducing the power consumption of a communication device that functions as an access point. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 illustrates an example of a configuration of a communication system. [Figure 2] FIG. 2 is a diagram illustrating an example of the hardware configuration of a communication device (AP / STA). [Figure 3]FIG. 2 is a diagram illustrating an example of the functional configuration of a communication device (AP / STA). [Figure 4] FIG. 1 is a sequence diagram showing the procedure of an LPL (Low Power Listen) function. [Figure 5] This is an example of an information element for notifying whether LPL is supported. [Figure 6] 10 is an example of an information element for notifying operation information of an LPL. [Figure 7] 10 is an example of an action frame for notifying operation information. [Figure 8] This is an example of an ICF. [Figure 9] This is an example of a response to an ICF. [Figure 10] 10 is a flowchart illustrating an example of control of an AP. [Figure 11] 10 is a flowchart illustrating an example of control of an AP. [Figure 12] 10 is a flowchart illustrating an example of control of an AP. [Figure 13] FIG. 1 is a transition diagram of operation modes and operation states for explaining an LPL function. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0013] First Embodiment An example of the configuration of a communication system according to this embodiment is shown in Fig. 1. The communication system according to this embodiment includes one access point device (hereinafter simply referred to as an AP, AP STA, or access point) and two station devices (hereinafter simply referred to as STAs, Non-AP STAs, or stations).

[0014] The AP 101 and the STA 102 are configured to be able to communicate wireless frames compliant with the IEEE 802.11bn standard, which is the successor to the IEEE 802.11be standard and targets a maximum transmission speed of 46.08 Gbps. The STA 103 is a legacy STA that can communicate wireless frames compliant with the IEEE 802.11be standard with the AP 101, but cannot communicate wireless frames compliant with the IEEE 802.11bn standard.

[0015] IEEE stands for Institute of Electrical and Electronics Engineers. IEEE802.11bn, the successor standard to IEEE802.11be, has high reliability, low latency, and improved throughput during congestion as its main features. One of the goals of 802.11bn is to reduce power consumption in APs. The wireless frame used in this successor standard is also called UHR (Ultra High Reliability) PPDU. PPDU stands for Physical Layer Protocol Data Unit.

[0016] The name UHR was chosen for convenience, taking into account the goals and key features of the successor standard, and may be renamed once the standard is fully established. Similarly, the name IEEE 802.11bn may be renamed once the standard is fully established. Note that this specification and the accompanying claims essentially apply to all successor standards to the 802.11be standard. AP 101 and STA 102 can also transmit wireless frames conforming to legacy standards that predate the IEEE 802.11bn standard. Examples of legacy standards include IEEE 802.11a / b / g / n / ac / ax / be standards.

[0017] The AP 101 and the STA 102 communicate by exchanging wireless signals in frequency bands such as the 2.4 GHz band, the 3.6 GHz band, the 5 GHz band, the 6 GHz band, and the 45 GHz band and 60 GHz band known as millimeter waves. The frequency bands used by the AP 101 and the STA 102 are not limited to these bands and may be, for example, the sub-1 GHz band. The AP 101 and the STA 102 may communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by the AP 101 and the STA 102 are not limited to these bands and may be, for example, 240 MHz or 4 MHz. The IEEE 802.11 series of standards specifies a frequency channel using a 20 MHz bandwidth as the basic channel in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands. This standard also defines multiple available channels in each of the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. This standard also allows a channel to be used in combination with an adjacent channel. In this embodiment, using a channel in combination with an adjacent channel is referred to as channel bonding. A channel bundle formed by one or two or more adjacent channels is referred to as a communication link. In other words, a link formed by combining two channels with a 20 MHz bandwidth uses a 40 MHz bandwidth. The AP 101 is an access point that supports a multi-band function and provides networks on multiple different frequency channels. In this embodiment, the AP 101 is illustrated as a dual-band access point that provides a 2.4 GHz band network and a 5 GHz band network.

[0018] The STA 102 establishes one or more links between the STA 102 and the AP 101 to communicate data with the AP 101 or other communication devices. For example, to establish a link with the AP 101, the STA 102 executes a connection procedure with the AP 101, which provides a BSS (Basic Service Set), which is a wireless LAN network. When the connection procedure between the STA 102 and the AP 101 is completed, a link is established between the devices. By establishing the link, the AP 101 and the STA 102 can access a wireless medium and communicate data, etc. with the other communication device.

[0019] Furthermore, the AP 101 and STA 102 of this embodiment can establish multiple links between devices and perform multi-link communication. Hereinafter, a communication link is also simply referred to as a link. The AP 101 that performs multi-link communication is also referred to as an AP MLD (AP Multi-Link Device) 101, and the STA 102 that performs multi-link communication is also referred to as a non-AP MLD 102. For example, the AP 101 can establish a link with the STA 102 in a 2.4 GHz band network and communicate with it. In parallel with this, the AP 101 and the STA 102 can establish a second link, for example, in the 5 GHz band, and communicate with it. In this case, the STA 102 performs multi-link communication using two links. The STA 102 can perform simultaneous transmit and receive (STR) operation with the AP 101, which allows simultaneous reception via link 1 and transmission via link 2. In addition, the STA 102 can perform NSTR operation with the AP 101, which is restricted to either using all links for transmission simultaneously or using all links for reception simultaneously. NSTR stands for Nonsimultaneous transmit and receive. NSTR operation is used when the frequency distance between links is close and mutual interference occurs. Hereinafter, multi-link operation, represented by STR and NSTR, will also be referred to as MLO.

[0020] For example, when link 1 using a 160 MHz bandwidth and link 2 using an 80 MHz bandwidth are established between devices, AP 101 and STA 102 communicate using the channels that make up the links. The link using a 160 MHz bandwidth is formed by bundling eight channels with a bandwidth of 20 MHz. The link using an 80 MHz bandwidth is formed by bundling four channels with a bandwidth of 20 MHz.

[0021] Furthermore, the AP 101 and the STA 102 can communicate using multiple spatial streams to communicate more efficiently with other communication devices. That is, they can perform SU-MIMO (Single User Multi-Input Multi-Output) communication using 2SS or 4SS. They can also perform MU-MIMO (Multi-User Multi-Input Multi-Output) communication using 2SS to 16SS. In SU-MIMO communication and MU-MIMO communication, the actual communication rate can be increased in proportion to the number of streams. Note that multiple spatial streams can also be used for higher reliability. Furthermore, in terms of modulation, communication can be performed using BPSK, QPSK, 16QAM, 64QAM, 256QAM, 1024QAM, 4096QAM, etc. to transmit information with higher density. MCS (Modulation and Coding Scheme) indicates the combination of the modulation method and modulation scheme such as the code rate as an index, and the AP 101 and the STA 102 can select one of MCSs from MCS0 to MCS15 to communicate.

[0022] As described above, communication devices such as STA102 communicate via multiple links using the MLO function described above, and receive data with multiple spatial streams, wide bandwidth, and high MCS. Therefore, it is generally necessary to control the signal receiving circuit and antenna so that all signal patterns can be received, even in an idle state waiting for reception. Utilizing these functions is certainly useful in terms of increasing communication speed and reliability, contributing to an improved user experience. However, there is also the problem that the power required for proper operation of communication devices increases not only during communication but also in an idle state waiting for communication to begin. In particular, the power consumption of access points that provide networks to multiple STAs is becoming non-negligible.

[0023] In view of this, this embodiment provides a specific mechanism for more actively reducing standby power consumption in an access point. Specifically, an LPL function is newly provided that communicates using communication parameters customized for power saving under multiple communication conditions, such as supporting only a small number of links, a small number of streams, and a low MCS. LPL stands for Low Power Listen. The LPL function actively reduces standby power consumption by selectively using LPL Enabled Mode and Active Mode, which is the normal operating mode. Hereinafter, for the sake of explanation, this new function will also be referred to as the Low Power Listen function. Another objective is to provide a mechanism for switching between enabling and disabling (disabling) the LPL function, taking into account whether a legacy terminal is participating at that time.

[0024] First, the concept of the LPL function will be explained using FIG. 13. FIG. 13 shows a transition diagram of communication device operation modes to explain the LPL function. Communication devices such as the AP 101 and the STA 102 support an Active Mode, which corresponds to normal operation, and an LPL Enabled Mode, in which the LPL function is enabled and actively reduces power consumption during standby. The LPL Enabled Mode is an example of a predetermined power-saving mode. The Active Mode is an example of a normal mode. Communication devices such as the AP 101 and the STA 102 operate in one of multiple operation modes, including at least the above two operation modes. In this embodiment, the Active Mode is also referred to as the LPL Disabled Mode or the LPL Disabled State. The Active Mode can also be considered a normal mode in which communication can be performed under normal communication conditions agreed upon between the AP and the STA. The STA 102 and the like operating in this Active Mode can perform multi-link communication with the AP 101, communication using multiple streams, communication using wide bandwidths such as 80 MHz, 160 MHz, and 320 MHz, and communication using a high MCS. Similarly, AP 101 operating in Active Mode can communicate with subordinate STAs under normal communication conditions. When switching operating modes, a communication device such as AP 101 notifies surrounding STAs connected to AP 101 that the mode will be switched. This notification can be made using an Action frame.

[0025] Communication devices such as the AP 101 and STA 102 that have transitioned to the LPL Enabled Mode operate in either the NPCS or LPCS state. NPCS stands for Normal Power Communication State, and LPCS stands for Low Power Listen Communication State.

[0026] Communication devices such as the AP 101 and STA 102 operating in the NPCS operating state can perform high-speed and / or highly reliable communication under normal communication conditions agreed upon between the AP and the STA, similar to Active Mode. The AP 101 and STA 102 transition their operating state to LPCS when a predetermined time has elapsed since the end of data communication with the outside world or when they communicate a frame indicating their intention to terminate communication, such as a CF-End frame indicating the end of a transmission opportunity. LPCS is an operating state that is expected to reduce power consumption. When transitioning to the LPCS operating state, the AP 101 and STA 102 switch their operation to a communication condition customized to reduce power consumption associated with waiting for communication, such as one link, one stream, a 20 MHz bandwidth, and a low MCS. Because of its characteristic of being able to maintain a state in which two-way communication is possible with low power consumption, in this embodiment, the state in which two-way communication is being performed or is possible in LPCS is also referred to as a Low Power Awake state. In other words, the Low Power Awake state is a state in which the device operates with lower power consumption than a state in which two-way communication is performed or possible in Active Mode or an NPCS operating state. In this embodiment, the communication condition with restrictions imposed when operating in LPCS is also referred to as Low Capability. The normal communication condition when operating in NPCS in Active Mode or LPL Enabled Mode is also referred to as High Capability. The LPL Enabled Mode can also be considered a mode that is estimated to consume less average power consumption than the Active Mode.

[0027] A communication device such as AP101 or STA102 operating in the LPCS operating state transitions the operating state of the communication device to NPCS in accordance with its own wishes or upon receiving a frame from the opposing communication device conveying a desire to communicate in normal mode.

[0028] In this way, communication devices such as AP 101 and STA 102 that operate in LPL Enabled Mode selectively use NPCS and LPCS as their operating states. For example, when normal communication is required, they transition to NPCS, enabling high-speed communication, and when in standby mode, they transition to LPCS, reducing power consumption. APs and STAs that operate in LPL Enabled Mode can achieve both convenience and power savings by selectively using these operating states.

[0029] Note that, in FIG. 13, two modes, Active Mode and LPL Enabled Mode, are illustrated as examples of multiple operating modes, but the present invention is not limited to these. Naturally, communication devices such as the STA102 can also support other operating modes, such as previously known Scheduled PS mode and Unscheduled PS mode. Communication devices such as the STA102 operating in these PS modes maintain a long Doze state and enter an Awake state only during the period when a DTIM is transmitted to monitor the presence of uplink data. DTIM stands for Delivery Traffic Indication Message. While operating in the PS mode, communication devices such as the STA102 maintain a Doze state for the most part, except for a very short Awake state period. During this Doze state, communication devices such as the STA102 stop supplying power to communication circuits. By performing these controls, the average power consumption during the period when the communication device operates in the PS mode can be reduced. Note that the Low Power Awake state may be used when operating in the Awake state in these Power Saving (PS) modes. Communication devices such as STA102 operating in these PS modes transition to LPL Enabled Mode or Active Mode based on their own preference or the DTIM reception status. The mode to transition to may be determined based on past communication results, etc. In this way, power consumption is reduced by appropriately switching between multiple operation modes depending on communication conditions, etc. Other operation modes may also include EMLSR (Enhanced Multi-Link Single Radio) mode.

[0030] In summary, the LPL Enabled Mode, in which the LPL function of this embodiment is enabled, is a mode with lower average power consumption than the Active Mode. Also, the LPL Enabled Mode has higher average power consumption than the Scheduled / Unscheduled PS Mode, but is a mode with high communication convenience, as it allows small data communications to be performed at any time.

[0031] A specific mechanism for switching the above modes will be described in detail using Figure 2 onwards. Note that, although Figure 1 shows, as an example, a communication system consisting of one AP 101 and two STAs 102 and 103, the number of STAs constituting the communication system may be greater than that shown in the figure.

[0032] The AP 101 and the STA 102 may also be configured to support wireless communication based on other communication standards, such as Bluetooth (registered trademark), NFC, or Bluetooth (registered trademark) LE (Low Energy). NFC stands for Near Field Communication. The AP 101 and the STA 102 may also be configured to support wired communication using an Ethernet 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 101 and the STA 102 may also be information processing devices, such as wireless chips that support the transmission and reception of UHR PPDUs. In this case, various controls may be performed by hardware circuits within the wireless chip. Various processes may also be performed by cooperation between a processor, memory, and hardware circuits, such as an ASIP, within the wireless chip. ASIP stands for Application-Specific Instruction Set Processor.

[0033] Specific examples of the STAs 102 and 103 include cameras, printers, tablets, smartphones, projectors, PCs, gaming devices, video cameras, smart glasses, head-mounted displays, and other wearable devices. Other examples include, but are not limited to, IoT devices such as sensor nodes and network video cameras. Other specific examples of the AP 101 include, but are not limited to, devices such as mobile routers, tablets, smartphones, and digital signage.

[0034] <Hardware configuration of communication device> 2 shows an example of the hardware configuration of a communication device (AP 101, STAs 102 to 103). The communication device includes, as an example of the hardware configuration, 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.

[0035] The storage unit 201 is configured with a ROM and / or 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, in addition to memories such as ROM and RAM, the storage unit 201 may also use storage media such as non-volatile storage devices such as hard disks and solid state drives (SSDs).

[0036] 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 programs stored in the storage unit 201 and controls the entire device by operating hardware circuits such as the ASIC. Note that 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).

[0037] The control unit 202 also controls the functional unit 203 to perform predetermined processing, such as capturing images, printing, and projection. The functional unit 203 is hardware that enables the device to perform predetermined processing. For example, if the communication device is a camera such as a digital still camera or a smartphone equipped with a camera, the functional unit 203 is an imaging unit that captures images of the surroundings via a camera unit (not shown) included in the communication device. For example, if the communication device is a printer, the functional unit 203 is a printing unit that prints on a sheet such as paper based on print data obtained from an external device via wireless communication. For example, if the communication device is a projector or smart glasses, the functional unit 203 is a projection unit that projects image data or video data obtained from an external device via wireless communication. In the case of smart glasses, the projection surface is the end user's retina, for example. The data processed by the functional unit 203 may be data stored in the storage unit 201 or data communicated with another AP or STA via the communication unit 206 (described later). Furthermore, communication devices such as the AP 101 can also provide network storage functions such as a network-attached storage (NAS). 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 101 or the like using a protocol such as SMB over QUIC. The communication device such as an STA then uploads files to the storage service and downloads files from the storage. This upload and download data communication is also achieved by communicating UHR PPDUs between devices. SMB stands for Server Message Block, and QUIC stands for Quick UDP Internet Connections.

[0038] The input unit 204 receives various operations from the user. The output unit 205 outputs various types of information 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 implemented by a single module, such as a touch panel. The output unit 205 functions as a display means for presenting information to the user. The input unit also functions as a reception means for receiving user operations.

[0039] The communication unit 206 controls wireless communications compliant with the IEEE 802.11 standard series and IP communications. In this embodiment, the communication unit 206 cooperates with the antenna 207 to execute communication control for transmitting and receiving UHR PPDUs, which are wireless frames of the UHR standard, and PPDUs conforming to earlier standards. The multiple antennas 207 are, for example, antennas capable of transmitting and receiving signals in at least one frequency band of the sub-GHz band, 2.4 GHz band, 5 GHz band, 6 GHz band, and millimeter wave band. While FIG. 2 illustrates an example in which the AP 101 and the STA 102 of this embodiment each have three antennas, this is not limiting and the number of antennas may be greater or less than three.

[0040] If the communication device is compatible with the NFC standard, Bluetooth standard, wired communication standard, or the like, the communication unit 206 may be configured to control wireless communication or wired communication in accordance with these communication standards. The communication units 206 of the AP 101 and the STA 102 each have a hardware circuit for decoding or encoding signals communicated over each link. Each antenna and hardware circuit is configured to be capable of individual power control. Alternatively, each link may be configured to have its own communication unit.

[0041] Next, the functional configuration of the AP 101 and the STA 102 will be described with reference to Fig. 3. The communication devices such as the AP 101 and the STA 102 have functional units such as a frame processing unit 301, a mode control unit 302, an RX / TX control unit 303, a frame transmission / reception unit 304, and a UI control unit 305.

[0042] The mode control unit 302 cooperates with each functional unit and each hardware unit to control the operation mode and connection with the other device. Specifically, the connection process involves authentication, association, and 4-way handshake processes to establish a communication link with the other communication device. In the case of the AP 101, the other device is a STA such as STA 102, and in the case of the STA 102, the other device is an AP such as AP 101. The control unit 302 also manages communication parameters to be used in each operation mode. When switching the operation mode, the control unit 302 requests the RX / TX control unit 303 to switch the communication conditions using the managed communication parameters. Upon receiving the switching request, the control units 303 and 304 control the communication unit 206 and the multiple antennas 207 to switch the communication conditions required for transmission and reception. The control unit 302 of the AP 101 also manages information about the STAs connected to the network provided by the AP 101. Specifically, the system manages identification information, such as a MAC address, that identifies each connected STA, in association with information indicating whether the STA supports wireless communication that complies with the 802.11bn standard.

[0043] The frame processing unit 301 generates and analyzes signals (frames) when communicating with a partner communication device. The frame processing unit 301 generates management frames for the communication device to execute connection procedures and control frames for controlling communication. The frames generated and analyzed by the processing unit include Beacon, Probe Request, Probe Response, Association Request, Association Response, F1S (Fast Initial Link Setup), Discovery, and Action. Also included are Authentication Request and Authentication Response frames. Also included are ReAssociation Request and ReAssociation Response. The processing unit 301 also generates and analyzes other IEEE 802.11 standard series frames as appropriate, but a description of these will be omitted due to space limitations.

[0044] The control frames generated and analyzed by the processing unit also include frames that transition the operational state of the LPL function when the function is enabled. For example, they also include frames that prompt a peer device, whose operational state is LPCS, to transition to NPCS. For convenience of explanation, these frames are referred to as ICFs (Initial Communication Frames). The frames generated and analyzed by the processing unit also include ICF Responses, which are responses to the ICFs. The management frames generated by the frame processing unit 301 are, of course, not limited to these. The frame processing unit 301 also generates data frames and QoS (Quality of Service) data frames based on instructions from upper-level applications (not shown). The frame processing unit 301 generates information elements such as UHR Capabilities elements and UHR Operation elements defined in the IEEE 802.11 series of standards. It can also generate UHR Protected action frames related to the LPL function.

[0045] This UHR Capabilities element can include an information element indicating whether AP101 and STA102 have the ability to execute the LPL function. Also, the elements within the UHR Protected action frame can include information elements for negotiating whether to enable the LPL function and the like. Details of these elements will be described later.

[0046] The frame transceiver 304 performs transmission processing of the wireless frame generated by the frame processor 301 and reception processing of the wireless frame from the counterpart device. The received digital data obtained by the reception processing is transferred to the processor 301. The processor 301 analyzes the received digital data transferred from the transceiver 304, and according to the analysis result, generates an appropriate response frame or notifies upper layers (not shown) of the analyzed data (such as IP data included in the payload). This frame transceiver 304 performs transmission control to transmit the frame in cooperation with each unit, or performs reception control to receive the frame.

[0047] The UI (User Interface) control unit 305 provides a setting screen as a UI for the user to input communication-related settings. Also, the UI control unit 305 receives user operations on the setting screen via the input unit 204, and stores the settings as operation settings of the communication device in the storage unit 201. The UI control unit 305 receives a setting change operation to enable or disable the LPL function via a setting screen (not shown). Also, it stores the user setting to enable or disable the LPL function corresponding to the setting change operation in the storage unit 201. The operation settings are appropriately referred to in the flowchart described later.

[0048] <Execution Procedure of LPL> Subsequently, using FIG. 4, the procedure for using the LPL function between AP101 and STA102 will be described. FIG. 4 is a sequence diagram showing the execution procedure of the LPL function performed between AP101 and STA102.

[0049] First, the STA 102 performs connection processing with the AP 101 (F401). The connection processing will be described. The AP 101 periodically broadcasts information necessary for other communication devices (such as the STA 102) to connect to the AP 101 using a Beacon frame or a FILS Discovery frame. By receiving the Beacon or FILS Discovery, the STA 102 recognizes APs such as the AP 101 present in the vicinity and initiates a wireless connection procedure. Note that if the AP 101 does not transmit a Beacon or if the STA 102 fails to properly receive a Beacon transmitted by the AP 101, the STA 102 may initiate a wireless connection procedure without receiving a Beacon. For example, the STA 102 may initiate a wireless connection procedure using connection information such as an SSID (Service Set Identifier) ​​or a passphrase registered in advance by a user or the like. To connect to the AP 101, the STA 102 first transmits a Probe Request frame to the AP 101. Upon receiving the Probe Request, the AP 101 transmits a Probe Response frame addressed to the STA 102. When connecting via Multi-Link, the Probe Request and Probe Response may be sent and received separately as ML Probe Request and ML Probe Response. When STA102 receives the Probe Response, it sends an Authentication Request frame to AP101. When AP101 receives the Authentication Request frame, it sends an Authentication Response frame to STA102. Each Authentication frame may be sent and received twice. When STA102 receives the Authentication Response frame, it sends an Association Request frame. When AP101 receives the Association Request frame, it sends an Association Response frame. Through these steps, a connection procedure is executed between AP101 and STA102, and a link is established between AP101 and STA102 using a wireless medium.After the above connection procedure, the AP 101 and the STA 102 may execute a 4-way handshake or the like to exchange security information. The AP 101 and the STA 102 may also execute the wireless connection procedure using a method other than the above.

[0050] The AP 101 and the STA 102 exchange capability information by including an information element indicating capability information indicating whether or not they support the Low Power Listen mode in at least one frame used in the wireless connection procedure.

[0051] Specifically, in a wireless connection procedure, the AP 101 and the STA 102 share capability information indicating whether the Low Power Listen mode is supported with the other communication device. The AP 101 and the STA 102 also share information that can identify the link, bandwidth, spatial stream, MCS, etc., to be used when executing Low Power Listen with the other communication device. In this embodiment, information for identifying optional functions supported by the communication device in wireless communication is called capability information.

[0052] A specific example of capability information exchanged during the wireless connection procedure will be described with reference to Fig. 5. As an example, capability information is transmitted to the other device using the UHR Capabilities element shown in Fig. 5(A). Fig. 5 shows an example of the UHR Capabilities element included in a frame for performing the wireless connection procedure.

[0053] The UHR Capabilities element is included in the above-mentioned Beacon, Probe Request, Probe Response, Association Request, Association Response, etc. In other words, the UHR Capabilities element is an information element that conveys capability information indicating whether optional functions of the 802.11bn standard are supported.

[0054] The UHR Capabilities element includes an Element ID field 501, a Length field 502, and an Extended Element ID field 503. The UHR Capabilities element further includes an LPL (Low Power Listen) Support field 504. Note that the UHR Capabilities element may also include fields indicating whether other optional capability information is supported. For example, a field indicating whether UORA (uplink OFDMA-based random access)-based low latency channel access is supported may be included.

[0055] The combination of the Element ID field 501 and the Extended Element ID field 503 uniquely indicates the type of element. In this embodiment, as an example, an element with 255 specified in field 501 and 138 specified in field 503 is defined as a UHR Capabilities element. However, this is not limited to this. Other combinations can also be defined as UHR Capabilities elements. The Length field 502 indicates the length of the element shown in FIG. 5. The LPL (Low Power Listen) Support field 504 stores a value indicating whether the communication device transmitting the frame supports the Low Power Listen function. Storing "1" in this field indicates that the communication device transmitting the frame supports the Low Power Listen function. Storing "0" in this field indicates that the communication device transmitting the frame does not support the Low Power Listen function or that the function is disabled.

[0056] Field 504 may be included in a subfield contained within a UHR Capabilities element, such as within a UHR MAC Capabilities Information field, but is not limited thereto, and field 504 may be defined as a field within a field conveying other sets of capability information.

[0057] FIG. 5(B) is a modified example of the UHR Capabilities field. The difference from FIG. 5(A) is that the LPL capability information is subdivided into an LPL Tx Support field 514 indicating transmission capability and an LPL Rx Support field 515 indicating reception capability. An AP must be able to transmit an ICF to an LPCS STA in order to transition the STA's operational state. Therefore, AP 101 must set the LPL Tx Support field 514 to 1. Setting this field by an AP to 1 means that the AP supports control of transmitting an ICF with the number of streams / MCS / number of links that an LPCS STA in the operational state can properly receive. STAs such as STA 102 may set the LPL Tx Support field 514 to 1. STAs such as STA 102 must also set the LPL Rx Support field 515 to 1. APs such as AP 101 must also set the LPL Rx Support field 515 to 1.

[0058] That is, in the modified example, field 514 indicates whether or not the device has the ability to transmit frames while maintaining the operating state of the LPCS, and field 515 indicates whether or not the device has the ability to receive data while maintaining the operating state of the LPCS.

[0059] It should be noted that elements including fields similar to fields 504, 514, and 515 in FIGS. 5A and 5B can also be configured to include frames different from the frames used in the wireless connection procedure described above.

[0060] The AP 101 and the STA 102 enable or disable the LPL function based on the communication status and the capability information indicating whether they support the LPL function that they notify or acquire from each other. In other words, they switch their operation mode to the Active Mode or the LPL Enabled Mode, as described with reference to FIG. 13.

[0061] In this embodiment, when the operating state of an STA such as STA 102 or an AP such as AP 101 is set to LPCS in LPL Enabled Mode, it is assumed that one specific link is used to listen for frames from the other device. However, this is not limited to this, and the number of links when operating in LPCS may be multiple. For example, if the number of links when operating in NPCS is three, it is sufficient to reduce the number of links when operating in LPCS to two, as long as the number of links is reduced compared to the number of links when operating in NPCS. That is, in this embodiment, it is assumed that the number of communication links in LPCS is reduced compared to NPCS or Active Mode. Furthermore, the number of links may be the same when the operating state is LPCS as when it is NPCS. In this case, when transitioning to LPCS, two or more other communication conditions, such as MCS and the number of spatial streams, may be customized for power saving, thereby reducing power consumption during standby.

[0062] An AP such as AP 101 can transmit detailed information about the operating parameters to be used by a STA operating in the LPCS state of the LPL Enabled Mode to the STA in advance using the UHR Operation element shown in FIG.

[0063] FIG. 6 shows an example of a UHR Operation element that the AP 101 includes in a frame used for wireless connection procedures.

[0064] By including the elements shown in Fig. 6 in a frame used for wireless connection procedures, AP 101 transmits to opposing devices such as STA 102 two or more communication conditions to be used when operating in an operating state such as LPCS. Specifically, AP 101 appropriately determines the link to listen on when a subordinate STA operates in LPCS with the LPL function, and the communication parameters to be used in LPCS. Then, AP 101 transmits Beacon, Probe Response, and Association Response frames including a UHR Operation element containing the determined communication parameters. Note that the UHR Operation element may be configured to be included in only one of the listed frames. The UHR Operation element may also be included in other frames.

[0065] Figure 6 shows an example of a UHR Operation element. The UHR Operation element includes an Element ID field 601, a Length field 602, and an Extended Element ID field 603. The UHR Operation element also includes a Padding Delay field 604a, a Transition Delay field 604b, an MCS field 605, and a Listen Link field 606. The UHR Operation element also includes a Listen Interval field 607, a duration field 608, and a Listen offset field 609. The Element ID field 601 and the Extended Element ID field 603 are fields for uniquely identifying elements. Therefore, a value different from the combination of 501 and 503 in Figure 5 described above is stored.

[0066] The Length field 602 stores the length of this element.

[0067] The Padding Delay field 604a stores the minimum MAC padding period that the AP 101 plans to include in the ICF. The Transition Delay field 604b stores the transition time required for the AP 101 to change its operating state from NPCS to LPCS. By notifying the AP 101 in advance of the time required to transition from LPCS to NPCS and the time required to transition from NPCS to LPCS using fields 604a and 604b, it becomes possible to appropriately determine the time to start communication in each state based on the transition time of the other party.

[0068] The MCS field 605 stores the upper limit of the MCS that the STA should support when operating in LPCS. For example, an upper limit value indicating that only MCSs up to QAMs lower than the QAM (e.g., 4096-QAM) that can be used when operating in NPCS (e.g., 16-QAM, 64-QAM, 256-QAM, etc.) are supported is stored. More specifically, this field can store an index value corresponding to the upper limit of the UHR-MCS that is expected to be used when operating in LPCS. For example, when "7" is stored, the upper limit of the usable MCS is 64-QAM with a coding rate of 5 / 6. In other words, when "7" is stored, the UHR-MCS that can be used when operating in LPCS is limited to the MCS indicated by any of the index values ​​0 to 6.

[0069] The Listen Link field 606 is a field that stores a Link ID that indicates which Link should be used to wait for reception when operating in LPCS.

[0070] The Listen Interval field 607, duration field 608, and Listen Offset field 609 are optional fields. These fields store parameters for enabling more power-saving reception standby. These fields are provided from the AP to the STA when optional control is performed to further reduce power consumption by providing Low Power Awake and Doze states within the LPCS operating state. The Listen Interval field 607 indicates the interval at which the STA enters the Low Power Awake state, allowing communication at low power while operating in LPCS. For example, if the value is set to 100, the STA transitions to the Low Power Awake state every 100 ms. The Listen Duration field 608 indicates how long the Low Power Awake state will last. For example, if the value is set to 15, the Low Power Awake state will be maintained for 15 ms. The Listen Offset field 609 indicates the time interval from beacon transmission to the Low Power Awake state. For example, if the value is set to 20, it indicates the initial time of the loop in which the STA enters the Low Power Awake state 20 ms after beacon transmission. Based on these parameters, STAs such as STA102 determine the time to enter Awake and the time to enter Doze, and control switching between Awake operation, which waits for communication in Low Capability, and Doze state based on the determined time. Therefore, even in the NPCS operating state, Doze operation can be performed for a certain period, enabling more adaptive power saving control. Note that other communication parameters may also be included. For example, parameters such as the number of spatial streams to be used in LPCS and parameters for the bandwidth to be used may be included.

[0071] Returning to the explanation of FIG. 4, the sequence for enabling the LPL function will be described. AP 101, which has determined that it wants to enable the LPL function and reduce power consumption, transmits a frame for enabling LPL to surrounding STAs connected to AP 101 (F402). The surrounding STAs (e.g., STA 102) that receive the frame transmit response frames. AP 101 that receives the response frame and STA 102 that successfully receives the frame for enabling LPL and transmits the response frame transition their operation modes to LPL Enabled Mode. Note that, in this embodiment, a case where the operation state transitions to the above-mentioned LPCS operation state in response to reception of the response frame is illustrated, but the present invention is not limited to this.

[0072] A frame for enabling the LPL will be described with reference to FIG. 7. FIG. 7 shows an example of the Action field of an Action frame that notifies the enabling / disabling of Low Power Listen. In this embodiment, this field is referred to as the Low Power Listen Mode Notification frame Action field. This is not limited to this, and this field may be called by another name. This field includes a Category field 701, a Protected UHR Action field 702, a Dialog Token field 703, and a Low Power Listen Control field 704. The Low Power Listen Mode Notification frame Action field may also include a Low Power Listen Parameter Update field 705. The Category field 701 indicates the category of this Action field. For example, the Category field 701 stores an identification number corresponding to the Protected UHR Action. The Protected UHR Action field 702 indicates an identifier of this Action field in the Protected UHR Action category. For example, the Protected UHR Action field 702 stores an identification number indicating the Low Power Listen Mode Notification frame Action field. The Dialog Token field 703 indicates an identifier for executing a series of information exchanges between the AP 101 and the STA 102. For example, an identifier assigned by the requesting communication device is stored in the Dialog Token field 703. The responding communication device stores the value contained in the received Dialog Token field 703 in the Dialog Token field 703 of a response frame and transmits the response frame. In addition, a MAC frame in which the Action field of FIG. 7 is stored is referred to as an LPL Operating Mode Notification frame.

[0073] The Low Power Listen Control field 704 includes an LPL Mode field 711 and a Low Power Listen Parameter Update Control field 712. The LPL Mode field 711 indicates whether or not the LPL function is to be used. For example, when the STA 102 requests that it start using the Low Power Listen function, it stores a 1 in this field. On the other hand, when the STA 102 requests that it stop using the LPL function, it stores a 0 in this field. The LPL Mode field 711 may be configured to have two bits so that it can indicate whether or not it will be used for transmission and reception, respectively. For example, when the STA 102 specifies a 0 in the first bit and a 1 in the second bit, the STA 102 requests that it will use the reception process during LPCS, but not the transmission process during LPCS.

[0074] The Low Power Listen Parameter Update Control field 712 indicates whether or not the Low Power Listen Parameter Update field 705 is present. For example, if the Low Power Listen Mode Notification frame Action field includes the Low Power Listen Parameter Update field 705, a 1 is stored in this field. On the other hand, if the Low Power Listen Mode Notification frame Action field does not include the Low Power Listen Parameter Update field 705, a 0 is stored in this field. The Low Power Listen Parameter Update field 705 includes a Padding Delay field 604a, a Transition Delay field 604b, an MCS field 605, a Listen Link field 606, a Listen Interval field 607, a Listen duration field 608, and a Listen offset field 609. These fields have the same functions as the fields with the same names described in FIG. 6, and therefore description thereof will be omitted. As in FIG. 6, parameters for the number of spatial streams to be used in the LPCS and parameters for the bandwidth to be used may also be included. When a STA such as the STA 102 wants to customize the communication parameters of the LPCS, it transmits an Action frame with a Low Power Listen Parameter Update field 705 added.

[0075] STAs such as STA 102 determine whether to use the LPL function based on the frame received from AP 101. Specifically, STAs such as STA 102 acquire the value of the LPL Mode field 711 included in the Low Power Listen Mode Notification frame Action frame received from AP 101. Then, the STAs determine the intention of the peer device, such as AP 101, based on the acquired value.

[0076] STAs such as STA102 respond to AP101 with a response frame that includes a Status Code in addition to the fields described in FIG. 7. AP101 analyzes the value of the Status Code in the response frame and determines whether the request to use the LPL function has been accepted by the STAs such as STA102. If the request is accepted, the STA changes its operating mode to the operating mode corresponding to the request. FIG. 4 illustrates an example in which AP101 requests to use the LPL function and STA102 accepts the request. AP101 and STA102 update their own communication parameters to those corresponding to LPCS. Specifically, if STA102 communicates updated communication parameter information using the Enabling sequence frame illustrated in F402, it sets the communication parameters. AP101 also sets communication parameters corresponding to LPCS. On the other hand, if updated communication parameter information is not communicated in the Enabling sequence, STA102 sets the communication parameters for LPCS shared in advance by AP101 using the UHR Operation element. The AP 101 also sets the previously shared communication parameters for the LPCS to itself. Then, the AP 101 and the STA 102 start frame waiting processing in the LPCS.

[0077] Next, the state transition from LPCS to NPCS will be described. When the AP 101 determines that data to be transmitted to the STA 102 has occurred, the AP 101 transmits an ICF to the STA 102, which causes the STA 102 to change its operating state from LPCS to NPCS (F403).

[0078] Upon receiving the ICF transmitted in F403, the STA 102 transmits a response signal to the ICF (F404). Specific examples of the ICF and the response signal to the ICF will be described using Figures 8 and 9. The ICF frame is a type of control frame and includes a Frame Control field 801, a Duration field 802, an RA field 803, a TA field 804, and a Link Info List field 805. The Frame Control field 801 is a field that identifies the type of frame and includes a value indicating that the frame is an ICF frame for the LPL function. The Duration field 802 indicates the maximum duration of the NPCS initialized by the ICF frame. The STA that received the ICF frame transitions to a state where it can receive frames with the parameters described in the Link Info List field while waiting for reception for the period described in this field. The RA field 803 stores the MAC address of the STA 102, which indicates the recipient of the frame. MAC stands for Medium Access Control. The TA field 804 stores the MAC address of the AP 101, which indicates the sender of the frame. The Link Info List field 805 stores information for identifying a link to be used in the NPCS state and one or more pieces of correspondence information that combine communication parameters for the link. When operating an STA in the NPCS operating state and enabling multiple links, the AP 101 stores multiple pieces of correspondence information in the List field 805. One piece of correspondence information consists of fields 811 to 815. The correspondence information will be explained in detail. The correspondence information includes a Link ID field 811, a BW field 812, an NSS field 813, an MCS field 814, and a Delay field 815. The Link Info List field 805 is information for identifying a link to be used in NPCS. Furthermore, fields 812 to 815 indicate communication parameters to be used when communicating over the link identified in 805. The following will be explained in detail. The BW field 812 indicates the bandwidth to be used for communication.For example, values ​​of 0, 1, 2, 3, and 4 indicate that frames should be listened for or transmitted at 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz, respectively. The NSS field 813 indicates the number of spatial streams. For example, it indicates that frames should be listened for or transmitted at a spatial stream equal to the value indicated by the field plus 1. NSS stands for Number of Spatial Streams. The MCS field 814 indicates the maximum MCS to be used for communication. The Delay field 815 specifies the delay time after transmitting an ICF frame before transmitting frames according to the specified parameters. This delay time is determined based on the padding delay received from the other device. Note that instead of 815, a padding field can be added to the end of the ICF frame for time adjustment. The ICF frame is transmitted over the link and bandwidth on which the STA 102 in the LPCS operating state is waiting for communication. On the other hand, an ICF may be simultaneously transmitted over a different link that is expected to be used for communication after transitioning to NPCS in order to secure transmission rights on that link.

[0079] Next, a response frame to an ICF will be described with reference to FIG. 9. FIG. 9 shows an example of an ICF Response frame. The ICF Response frame may include a Frame Control field 801, a Duration field 802, an RA field 803, a TA field 804, a Status Code field 901, and a Link Info List field 805. Fields that overlap with those in FIG. 8 are given the same numbers, and their descriptions will be omitted. The Status Code field 901 indicates whether communication is possible with the value specified in the ICF. Note that the transmission of the ICF Response frame can also be omitted. Alternatively, a configuration may be adopted in which a CTS (Clear To Send) frame is returned instead of the ICF Response frame shown in FIG. 9. In this case, the CTS frame may be returned every 20 MHz across all links and bandwidths specified in the ICF.

[0080] Next, STA 102 starts waiting for frames using NPCS. Specifically, STA 102 updates its own communication parameters with the communication parameters included in the ICF and starts waiting for frames using communication parameters corresponding to NPCS. In other words, STA 102 switches to a HighCapability communication condition for high-speed communication and highly reliable communication. AP 101 also updates its own communication parameters with the communication parameters corresponding to NPCS included in the ICF.

[0081] After changing the communication parameters and waiting for a grace period if necessary, the AP 101 transmits a data frame to the STA 102 (F405). The AP 101 transmits the data frame with the transmission parameters corresponding to the HighCapability notified in F403.

[0082] Upon receiving the data frame, the STA 102 returns an Ack frame as a response frame to the received data frame (F406). The STA 102 and the AP 101 can transmit downlink data by repeating the sequences indicated in F405 and F406 during the grace period indicated in the Duration field of the ICF.

[0083] When the AP 101 determines that a series of data transmissions to the STA 102 is complete, it transmits a CF-End frame or a QoS Null frame (F407). This frame functions as a frame that terminates the NPCS operating state and prompts transition to the LPCS state. The frame that prompts transition to the LPCS is not limited to this, and other frames may be used. For example, it may be a control frame newly defined for the LPL function. Upon receiving the CF-End frame or the QoS Null frame, the STA 102 changes its operating state back to LPCS. The CF-End frame and the QoS Null frame are examples of termination frames. In other words, the AP 101 or the STA 102 switches to a Low Capability communication condition, which intentionally limits functionality for power saving.

[0084] Note that FIG. 4 illustrates an example in which downlink communication is triggered by an ICF issued by the AP 101. On the other hand, if the STA 102 determines that it wishes to perform high-speed and / or high-reliability communication on its own initiative, such as when uplink data is generated, the STA 102 may be configured to transmit an ICF to the AP 101. Upon receiving the ICF, the AP 101 transmits an ICF Response and transitions to the NPCS mode. The STA 102 similarly transitions to the NPCS mode upon receiving the ICF Response from the AP 101. The STA 102 that has transitioned to the NPCS mode may be configured to transmit a data frame using transmission parameters corresponding to the updated communication conditions. After completing a series of data transmissions, the STA 102 determines that it should switch its operating mode to the LPCS mode and transmits a CF-End frame. Note that instead of the CF-End frame, the STA 102 may transmit a QoS Null frame or a QoS Data frame in which the RDG / More PPDU subfield of the CAS Control field is set to 0. After transmitting the frame, the STA 102 transitions its operating state to the LPCS mode. The AP 101, which received the frame, also transitions its own operating state to LPCS. That is, the AP 101 and the STA 102 switch to a communication condition of LowCapability, which intentionally limits functionality.

[0085] Although omitted from Figure 4 due to space limitations, if the AP 101 or STA 102 determines that the operating mode should be changed to Active Mode depending on the communication conditions, etc., it sends a request to disable the LPL to the AP 101. Upon receiving this request, the AP 101 or STA 102 sends a response frame indicating that it has accepted the LPL disabling. In these LPL Disabling sequences, disabling can be requested using the LPL Operating Mode Notification frame described using Figure 7. When requesting disabling, the AP 101 or STA 102 stores 0 in the LPL Mode field included in the frame to request disabling.

[0086] <Communication control utilizing the LPL function> Next, the communication control utilizing the LPL function of the present embodiment will be described using the flowcharts of FIGS. 10 and 11.

[0087] FIG. 10 is a flowchart for explaining an example of connection control and disconnection control in AP101, and FIG. 11 is a flowchart for explaining an example of communication control in AP101.

[0088] Each process shown in the flowcharts of FIGS. 10 and 11 is executed by the processor of the control unit 202 of AP101 executing the computer program stored in the storage unit 201. Note that some processes such as transmission and modulation are realized by the cooperation of the processor of the control unit 202 and various processors, ASICs, DSPs, FPGAs, antennas constituting the communication unit 206, and ASICs, DSPs, FPGAs, etc. constituting the control unit 202. Note that it is of course possible to configure the communication unit 206 and the antenna to cooperate and execute each process shown in the flowchart without being limited to this. When it is desired to clearly indicate the subject of the process, the functional units described in FIG. 3 will be used as the subject for explanation. Note that the control indicated by the dotted line is optional control, and it is not necessarily required to execute such control.

[0089] First, the control when a station connects to AP101 and the control when a station disconnects from AP101 will be described using FIG. 10. Each process shown in FIG. 10(A) is an extraction of a series of control processes when a slave station tries to connect to the network provided by AP101. Also, each process shown in FIG. 10(B) is an extraction of a series of control processes when a slave station disconnects from the network provided by AP101.

[0090] First, the control at the time of connection will be described. In S1000, the mode control unit 302 of the AP 101, which has been turned on and started operating, activates the LPL function of the AP and starts control to notify that the LPL mode is available. Specifically, the availability of the LPL function is notified by transmitting a Beacon frame including information indicating that the LPL mode is supported in the UHR Capabilities Element described in FIG. 5. This notification makes it possible to convey to stations that support IEEE 802.11bn that the LPL function can be used.

[0091] In S1001, the control unit 202 determines whether or not a connection request has been received from an STA such as the STA 102. If it is determined that a connection request has been received, the process proceeds to S1001, and if it is determined that a connection request has not been received, the control unit 202 performs a process of waiting for a connection request.

[0092] In S1002, the control unit 202 performs the connection process described in FIG. 4 and acquires capability information of the STA from a frame received from an STA such as STA 102 for the connection process. Specifically, capability information such as the UHR Capabilities element described above and the EHT Capabilities element and HE Capabilities element, which are capability information in the legacy standard, is acquired. EHT stands for Extremely High Throughput. HE stands for High Efficiency. Note that, in the connection process, a legacy terminal such as STA 103 transmits a frame that does not include a UHR Capabilities element, which is capability information in the IEEE 802.11bn standard. The capability information acquired in S1001 is referred to as appropriate in steps described later. Also, in S1002, the control unit 202 of AP 101 cooperates with the STA of the opposite device to perform the connection process shown in FIG. 4 and complete the connection.

[0093] Next, in S1003, the mode control unit of the AP 101 determines whether the LPL function of the AP 101 is enabled. If it is determined that the LPL function is enabled, the process proceeds to S1004, and if it is determined that the LPL function is not enabled, the series of processes for connection is terminated.

[0094] In S1004, the control unit 202 determines whether the newly connected STA is a legacy terminal based on the capability information acquired in S1002. If it is determined that the STA is a legacy terminal, the process proceeds to S1006; if it is determined that the STA is not a legacy terminal, the process proceeds to S1005. More specifically, if the capability information acquired in S1002 includes a UHR Capabilities element, the control unit 202 determines that the STA is a non-legacy terminal that supports the IEEE 802.11bn standard. On the other hand, if the capability information acquired in S1001 does not include a UHR Capabilities element, the control unit 202 determines that the STA is a legacy terminal that does not support the IEEE 802.11bn standard. A non-legacy terminal that supports the IEEE 802.11bn standard is an example of a specific type of station. A legacy terminal that does not support the IEEE 802.11bn standard is an example of a non-specific type of station.

[0095] In S1005, the control unit 202 determines whether the connected STA is a station that supports the LPL function. More specifically, if the control unit 202 determines that the connected STA is a station that supports the LPL function based on the information indicated in the UHR Capabilities element acquired in S1001, the control unit 202 ends the series of processes. On the other hand, if the control unit 202 determines that the connected STA is a station that does not support the LPL function based on the information, the control unit 202 proceeds to S1006. Note that it is also possible to configure stations that support IEEE802.11bn to always support the LPL function. In this case, the process of S1005 can be omitted.

[0096] In S1006, the frame transmission / reception unit 304 cooperates with each unit to transmit a frame requesting that the STA in LPL Enabling Mode transition to LPL Disabled Mode. The transmission of this frame triggers an operation to transition the operation mode of the STA currently operating in LPL Enabled Mode to LPL Disabled Mode (Active Mode). More specifically, the AP 101 requests the disabling of the LPL by generating and transmitting an LPL Operating Mode Notification frame in which 0 is stored in the LPL Mode field 711 of the Action field of the Low Power Listen Mode Notification frame described with reference to FIG. 7.

[0097] Next, in S1007, the mode control unit 302 disables the LPL function of the AP 101. Then, the mode control unit 302, in cooperation with the RX / TX control unit 303, performs processing to transition the operation mode of the AP 101 to Active Mode. When transitioning to Active Mode, the RX / TX control unit 303 controls each unit of the AP 101 and performs processing to switch to a communication condition corresponding to High Capability. Note that if the AP 101 is operating in the NPCS state of LPL Enabled Mode, switching the communication condition can be omitted. Next, the frame transmission / reception unit 304 starts control to notify that the LPL mode is unavailable. Specifically, the frame transmission / reception unit 304 notifies that the LPL function is disabled by transmitting a Beacon frame including information indicating that LPL is not supported or is disabled. This notification makes it possible to notify stations that support IEEE 802.11bn that the LPL function is unavailable. Furthermore, by performing the control described in S1004 to S1006, if a station that does not understand that the AP can operate in the LPCS state using the LPL function connects to the AP 101, the LPL function can be disabled. Also, if the LPL function is disabled due to the connection of a legacy terminal, the AP can transition to a state that notifies that the LPL function is not supported. Therefore, it is possible to prevent inconveniences from occurring even if a connection with a legacy terminal or a station that does not support the LPL function connects.

[0098] Next, a series of controls when a station, which is a slave device, leaves the network provided by the AP 101 will be described with reference to FIG.

[0099] In S1010, the control unit 202 determines whether the STA will leave the network provided by the AP 101. Specifically, when a Disassociation frame or a Deauthentication frame is received from the STA, the control unit 202 determines that the STA that sent the frame will leave the network provided by the AP 101. Also, when data communication with a specific STA is not possible until a predetermined timeout period has elapsed after communication with the specific STA has been lost, the control unit 202 determines that the specific STA will leave the network provided by the AP 101.

[0100] In S1011, the mode control unit 302 performs an update process to delete information about the STA determined to leave in S1010 from information about STAs currently connected to the network provided by the AP 101. Subsequently, in S1012, the mode control unit 302 determines whether the number of legacy terminals connected to the AP has become zero, based on information about STAs currently connected to the network provided by the AP 101 that the mode control unit 302 manages. If the mode control unit 302 determines that the number of legacy terminals has become zero, the process proceeds to S1014. On the other hand, if the mode control unit 302 determines that the number of legacy terminals has not become zero (i.e., if the mode control unit 302 determines that one or more legacy terminals are connected to the network provided by the AP 101), the process ends. Specifically, the control unit 302 refers to information about connected STAs that the mode control unit 302 manages, and if the control unit 302 determines that the only STAs currently connected to the mode control unit 302 are terminals that support IEEE 802.11bn, the control unit 302 determines that the number of legacy terminals has become zero. The control unit 302 also determines that the number of legacy terminals has become zero if the number of connected STAs has become zero.

[0101] In S1014, the mode control unit 302 enables the LPL function of the AP. Subsequently, the mode control unit 302, in cooperation with the frame transmission / reception unit, starts control to notify that the LPL function is available. Specifically, the mode control unit 302 notifies the surrounding area that the LPL function is available by starting a process of periodically transmitting a Beacon frame including information indicating that the LPL function is supported in the UHR Capabilities Element described in FIG. 5 to the surrounding area. This notification can notify stations that support IEEE 802.11bn that the LPL function is now available for use.

[0102] 10(A) and 10(B) described above, it becomes possible to operate the AP 101 so that the LPL function is not available when one or more legacy terminals are connected to the network provided by the AP 101. Also, when there are no legacy terminals connected to the network provided by the AP 101, it becomes possible to operate the AP 101 in a state where the LPL function is available.

[0103] Next, the control of the AP 101 will be described with reference to Fig. 11. Each control shown in Fig. 11 indicates a process that is executed after power is supplied to the AP 101, the startup sequence is completed, and normal operation as an AP is started.

[0104] In S1100, the control unit 302 of the AP 101 determines whether the AP 101 is operating in the LPCS state. If it is determined that the AP 101 is operating in the LPCS state, the process proceeds to S1101, and if it is not determined that the AP 101 is operating in the LPCS state, the process proceeds to S1108.

[0105] In S1101, the processing unit 301 cooperates with each unit to determine whether an ICF for transitioning from LPCS to NPCS has been received from a subordinate STA. If it is determined that an ICF for transitioning from LPCS to NPCS has been received, the processing proceeds to S1105.

[0106] Next, in S1102, the processing unit 301 determines whether there is data to be transmitted to the STA. If there is data to be transmitted to the STA, the process proceeds to S1103. If there is no data to be transmitted to the STA, the process proceeds to S1108 while maintaining the LPCS state. If it is determined that there is data to be transmitted, the frame processing unit 301 identifies the traffic type required for transmitting data to the destination STA for which it has been determined that data transmission is necessary and estimates the traffic volume. For example, the processing unit 301 identifies the traffic type to which the data is classified based on the QoS information of the data. Furthermore, for example, the processing unit 301 stores past communication records and the like, and estimates the traffic volume, which is the characteristic of the traffic to be generated, by comparing the communication records with the characteristics of the data to be transmitted (for example, data source information / destination information, etc.). Note that the estimation method is not limited to this.

[0107] Then, in S1103, the processing unit 301 determines whether or not the estimated traffic should be communicated while maintaining the LPCS state. If it is determined that the estimated traffic should be communicated while maintaining the LPCS of the destination STA, the processing proceeds to S1112. On the other hand, if it is not determined that the estimated traffic should be communicated while maintaining the LPCS of the destination STA (i.e., if it is determined that a transition to NPCS should be made), the processing proceeds to S1103. For example, it determines whether or not the transmission time when transmitting the estimated traffic volume at the communication rate for communication while maintaining the LPCS will fit within a predetermined time. If it is determined that it will fit within the predetermined time, it determines that the estimated traffic should be communicated while maintaining the LPCS of the destination STA.

[0108] In S1112, the processing unit 301 cooperates with the transmitting / receiving unit 304, the communication unit 206, and the antenna 207 to transmit data using communication parameters for LPCS.

[0109] Meanwhile, in S1104, the processing unit 301 cooperates with the various units to transmit the ICF described in FIG. 8 to the destination STA. At this time, the processing unit 301 cooperates with the mode control unit 302 to determine communication parameters to be used when the destination STA transitions to the NPCS, based on the traffic characteristics (traffic type and traffic volume) identified and estimated in S1101. At this time, the mode control unit 302 manages the determined communication parameters and operation state as current state information associated with the destination STA. In other words, the control unit 302 updates the operation state included in the state information corresponding to the destination STA from the LPCS to the NPCS, and stores the communication parameters used in the NPCS as state information. Then, the processing unit 301 transmits an ICF including, in field 805, communication conditions corresponding to the determined communication parameters.

[0110] In S1105, the processing unit 301, in cooperation with the control units 302 and 303, the transceiver unit 304, the communication unit 206, and the antenna 207, transitions the operation mode to NPCS and changes its own communication parameters to HighCapability. Then, if necessary, it waits for the transition time until the STA transitions to NPCS mode, and then transmits data to the destination STA using the communication parameters notified in the ICF. If the processing unit 301 determines that transmission of a series of traffic data to the destination STA is complete based on the data accumulation status in the transmission buffer, etc., it proceeds to S1106. Note that when the AP 101 receives an ICF in S1101, the processing unit 301 receives data from the STA that sent the ICF using communication parameters corresponding to NPCS.

[0111] In S1106, the processing unit 301 transmits a CF-End frame or a QoS Null frame in response to the completion of a series of traffic transmissions. Upon completion of transmission, the AP 101 advances the process to S1106. Note that the AP 101 may also receive a CF-End frame or a QoS Null frame from the STA, which is the opposite device. In consideration of this case, even when the AP 101 determines that it has received a CF-End frame or a QoS Null frame from the STA, which is the opposite device, the AP 101 considers that a series of traffic communications has been completed, and executes the state change process of S1107.

[0112] In S1107, the processing unit 301 requests the mode control unit 302 to update the operation state to LPCS. Upon receiving the request, the control unit 302 updates the operation state of the AP 101 from NPCS to LPCS, thereby causing the AP 101 to transition back to the LPCS state. Upon completing the transition back to the LPCS state, the control unit 202 advances the process to S1108.

[0113] In S1108, the mode control unit 302 determines whether enabling / disabling of the LPL of the AP 101 is necessary. Specifically, when the control unit 302 receives an LPL Operating Mode Notification frame in cooperation with each unit, it determines whether enabling / disabling of the LPL is necessary. The control unit 302 also determines whether enabling / disabling of the LPL is necessary based on the communication status. For example, if a situation in which data transmission frequency is low continues, it can determine that enabling of the LPL is necessary. Furthermore, for example, if a large amount of downlink data or low-latency data has occurred or is likely to occur, it can determine that disabling of the LPL is necessary. This means that the AP determines that the operation mode should be changed if it estimates that the current operation mode is not suitable or will no longer be suitable based on the communication status known to the AP.

[0114] If it is determined that enabling / disabling of the LPL is necessary, the process proceeds to S1109, and if it is not determined that enabling / disabling of the LPL is necessary, the process proceeds to S1110.

[0115] In S1109, the control unit 302 executes the LPL enabling / disabling procedure in cooperation with each unit, and updates its own operating mode to a new operating mode (LPL enabled mode or active mode). When transitioning from active mode to LPL enabled mode, the control unit 302 notifies the connected STA of the enablement of the LPL function using the LPL Operating Mode Notification frame described with reference to Fig. 7. When transitioning from LPL enabling mode to active mode, the control unit 302 notifies the STA of the transition to active mode using a similar frame.

[0116] Meanwhile, in S1110, the control unit 202 determines whether to stop the AP operation. If it is determined that the AP operation should be stopped, the series of processes ends. If it is determined that the AP operation should not be stopped, the process proceeds to S1110. For example, the control unit 202 can determine to stop the AP operation when it receives a user operation to press a shutdown button or a power button (not shown).

[0117] In S1111, the control unit 202 executes other communication controls. Specifically, the control unit 202 performs the connection control described in Fig. 10, the control of STA disconnection determination, the broadcast control of management frames such as beacons, etc. The control unit 202 also performs other control such as data communication control in the Active Mode state and data reception control from the STA while maintaining the LPCS state.

[0118] Note that STAs connected to the AP 101 network that support the LPL function switch their operation to LPL mode or Active mode in response to an operation mode notification from AP 101. STAs operating in the LPCS state in LPL mode in accordance with AP 101 transmit the ICF shown in Figure 8 to AP 101 when they want to transmit low-latency data or large amounts of data to AP 101. This transmission causes the STA to prompt AP 101 to return to NPCS mode. Similarly to the AP side, if a STA operating in the LPCS state determines that communication should be maintained while maintaining LPCS, it can also be configured to transmit data to AP 101 while maintaining LPCS.

[0119] Through the series of controls described above, AP 101 that supports the LPL function can change operation from LPL Enabled Mode to Active Mode when a legacy terminal connects. Also, AP 101 that does not have a legacy terminal connected can use the LPL function as appropriate, making it possible to reduce average power consumption compared to when always operating in Active Mode.

[0120] <Second embodiment> In the first embodiment, when a legacy terminal connects, the AP transitions to an operation mode that does not use the LPL function, taking the legacy terminal into consideration. In the second embodiment, assuming that the AP provides the MLO function, a mechanism is provided in which a BSS that does not use the LPL function is provided for legacy terminals, while a BSS that can use the LPL function is provided for non-legacy terminals. Specifically, at least one affiliated AP operates in an operation mode that does not use the LPL function, and at least one other affiliated AP operates in an operation mode that uses the LPL function. Then, when a legacy terminal attempts to connect to a BSS in an operation mode that uses the LPL function, a mechanism is provided in which the legacy terminal is controlled to connect to a BSS in an operation mode that does not use the LPL. That is, the second embodiment is based on the premise that the AP 101 operates as an AP MLD. Note that the hardware and software configurations of the AP 101 and the STAs 102 and 103 are the same as those in the first embodiment, and therefore description thereof will be omitted. Specific control will be described using the flowchart of FIG. 12.

[0121] Fig. 12 is a flowchart illustrating an example of communication control in AP 101. Fig. 12(A) shows control at the time of startup of AP 101, and Fig. 12(B) shows an example of control when a STA attempts to connect to a network provided by AP 101.

[0122] Each process shown in the flowchart in Fig. 12 is executed by the processor of the control unit 202 of the AP 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 working in cooperation with various processors, ASICs, DSPs, FPGAs, etc., that constitute the communication unit 206, and the ASICs, DSPs, FPGAs, etc., that constitute the antenna and control unit 202. Note that this is not a limitation, and it is of course also possible to configure the communication unit 206 and the antenna to work in cooperation to execute each process shown in the flowchart. Note that 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 in the description.

[0123] First, the control at startup will be described using FIG. 12(A). AP 101 has a Multi-Link Upper MAC sublayer component (not shown), which comprehensively manages the lower sublayers, thereby realizing Multi-Link communication. This lower sublayer is realized by a combination of a Lower MAC sublayer component and a PHY that corresponds one-to-one to the component. AP 101 also has a non-Multi-Link Upper MAC sublayer component so that it can communicate with STAs that support only Single-Link communication. The combination of the non-Multi-Link Upper MAC sublayer and Lower MAC sublayer components and the PHYs associated with these components logically functions in the same way as a conventional single access point. In other words, the combination of these components and PHYs is used to realize Single-Link communication with legacy terminals that support only standards prior to 802.11ax. This single access point can also be considered as an affiliated AP managed by the Multi-Link function, and is therefore also called an Affiliated AP (Access Point). At S1200, the mode control unit 302 of the AP 101 starts operation with the MLO function. That is, it activates the components of the Multi-Link Upper MAC sublayer described above. Then, it activates the components serving as the Lower MAC sublayer corresponding to the Affiliated APs, and sets communication parameters for the PHYs that correspond one-to-one to the components. At this time, the mode control unit 302 causes at least one of the Affiliated APs to function as an AP that is in LPL Disabled Mode and that notifies, by a beacon frame, that the LPL is unavailable. The mode control unit 302 also causes at least one of the Affiliated APs to function as an AP that is in LPL Enabled Mode and that notifies, by a beacon frame, that the LPL is available. The number of Affiliated APs provided by the AP 101 may be any number equal to or greater than two.

[0124] 12B, a description will be given of the control when a STA connects to AP 101. In S1210, the control unit 202 determines whether a connection request has been received from a STA such as STA 102 or STA 103. If it is determined that a connection request has been received, the process proceeds to S1211, and if it is determined that a connection request has not been received, the control unit 202 performs a standby process for the connection request.

[0125] In S1211, when attempting the connection processing described in Fig. 4, the control unit 202 acquires capability information of the STA from a frame received from the STA such as STA 102 for the connection processing. Specifically, capability information such as the UHR Capabilities element described above and the EHT Capabilities element and HE Capabilities element, which are capability information in the legacy standard, is acquired. The capability information acquired in S1212 is referred to as appropriate in steps described later.

[0126] Subsequently, in S1212, the control unit 202 determines whether the legacy terminal desires the establishment of a link including an Affiliated AP operating in LPL Enabled Mode. If the control unit 202 determines that the legacy terminal desires the establishment of a link including an Affiliated AP operating in LPL Enabled Mode, the control unit 202 proceeds to S1214. On the other hand, if the control unit 202 determines that the legacy terminal does not desire the establishment of a link including an Affiliated AP operating in LPL Enabled Mode, the control unit 202 proceeds to S1213. Whether the STA that transmitted the connection request is a legacy terminal is determined by performing the same determination control as the determination control in S1004 of the first embodiment, based on the capability information acquired in S1211. Furthermore, whether a link including an Affiliated AP operating in LPL Enabled Mode is desired in the connection request can be determined based on which Affiliated AP the request was received via. When a request is received via an Affiliated AP operating in LPL Enabled Mode, the control unit 202 determines that a link including an Affiliated AP operating in LPL Enabled Mode is desired to be established. Furthermore, when an ML Association Request for establishing multiple links including a Multi-Link Element (hereinafter also referred to as an MLE) is received, the control unit 202 performs the following determination control: If the link ID in the MLE indicates an Affiliated AP operating in LPL Enabled Mode, the control unit 202 determines that a link including an Affiliated AP operating in LPL Enabled Mode is desired to be established. In summary, when both conditions are met—that the sender of the connection request is determined to be a legacy terminal and that the desired link includes an Affiliated AP operating in LPL Enabled Mode—the control unit 202 proceeds to the process of S1214.

[0127] In S1214, the control unit 202 performs control so that links corresponding to Affiliated APs operating in Avtive Mode (LPL Disabled Mode) are established. Specifically, when the control unit 202 receives an ML Association Request from a legacy terminal that supports the IEEE 802.11be standard but does not support the 802.11bn standard, the control unit 202 denies establishment of some of the requested links. By denial of establishment of some of the links, control can be performed so that only links corresponding to Affiliated APs operating in Avtive Mode (LPL Disabled Mode) are established.

[0128] Furthermore, if an Association Request frame transmitted by a legacy terminal is received via an Affiliated AP operating in LPL Enabled Mode, the legacy terminal transmits an Association Response indicating a rejection. In this case, the control unit 202 generates and transmits an Association Response with the Status Code set to "REJECTED_WITH_SUGGESTED_BSS_TRANSITION." Furthermore, the Association Response includes information identifying another Affiliated AP providing a network in Active Mode from the AP 101 as information identifying a recommended BSS as a connection destination candidate. The connection destination candidate BSS may be included in a Neighbor Report Information element. A STA that receives the rejection response can attempt to connect to the recommended BSS as a connection destination candidate. This can prompt the STA to connect to Active Mode (LPL Disabled Mode). Note that the Association Request may be accepted and a link established with the STA may be followed by a roaming instruction. Specifically, a BSS Transition Management Request frame may be transmitted to the STA with which the link has been established. This transmission causes the STA to transition control to an Affiliated AP operating in Active Mode.

[0129] Finally, the control when a connection request is received from a non-legacy terminal and a connection request to connect only to Active Mode APs is described. In S1213, the control unit 202 establishes one or more links according to the request of the STA, and ends the series of connection processing. After the connection processing is completed, data communication is performed as appropriate.

[0130] Furthermore, in the second embodiment, the AP 101 supports the MLO function and includes multiple Affiliated APs. However, the present invention is not limited to this. The above-described technology can also be applied to an AP that provides a Multi-BSS (Multiple Basic Service Set) function. The Multi-BSS function refers to a function in which the AP 101, which is a single physical access point, provides multiple BSSs. In this case, for example, the AP 101 is configured to provide a first BSS corresponding to a first SSID in an operation mode that uses the LPL function, and a second BSS corresponding to a second SSID in an operation mode that does not use the LPL function. Then, when a legacy terminal attempts to connect to the second BSS provided by the AP 101, the above-described control may be performed so that the legacy terminal connects to the first BSS, which is different from the second BSS.

[0131] Furthermore, the LPL function of the second embodiment may be a mode that reduces power consumption using a different algorithm from the mode that waits for communication in a state changed to a condition estimated to consume less power than the normal mode described above. For example, the LPL function may be a mode that reduces power consumption by switching between an inactive state (sleep state) and an active state corresponding to Active Mode according to a predetermined time schedule. In this case, the AP 101 determines a schedule for the active and inactive periods of the affiliated APs that use the LPL function. The AP then notifies the non-legacy STAs of the determined schedule. This notification allows the STAs and the AP to share periods during which data communication is possible and impossible using communication parameters corresponding to NPCS. An AP that transitions to LPL Enabled Mode reduces power consumption by maintaining a Doze state for a certain period based on the notified schedule, and provides opportunities for data communication to the STAs by operating in Active Mode for another certain period. The determined schedule can be shared by negotiating with neighboring APs, for example, by extending the TWT Element defined in the IEEE 802.11ax standard. In other words, power consumption can be reduced by operating according to the negotiated schedule.

[0132] <Variation 1> In the above-described embodiment, a frame including a UHR Operation element or an LPL Operating Mode Notification frame is used to notify the MCS, number of spatial streams, and other parameters used in the LPCS operating state. However, this is not limiting. It is also possible to notify only information identifying the link corresponding to 606, and use predefined communication parameters for other communication parameters. Predefined communication parameters can be, for example, communication parameters that use one spatial stream, the minimum MCS required to receive control frames such as ICF, and only the primary 20 MHz bandwidth. A specific example is described below. STA 102 operates as a non-AP MLD and performs multi-link communication established with AP 101 in Active Mode. One of these links can also utilize MIMO communication, enabling communication with a high MCS and a 160 MHz bandwidth. In this state, upon receiving an LPL Operating Mode Notification, STA 102 changes its condition to one that allows communication with a 20 MHz bandwidth over a single link identified by the link ID. Furthermore, it changes its condition to one that allows communication with a single spatial stream without using MIMO or the like.

[0133] <Variation 2> In the above embodiment, the ICF frame includes communication parameters to be used after transitioning to the NPCS state of the LPL, but this is not limiting. For example, transmission of the communication parameters may be omitted. In this case, a configuration may be adopted in which default communication parameters are used when returning to the NPCS state. For example, the default communication parameters may be the communication parameters used when operating in Active Mode negotiated during connection processing.

[0134] <Variation 3> 5A and 5B, the information on whether the LPL function is supported, which is included in the UHR Capabilities element, can also be configured to be included in the Multi-Link element. For example, a new field such as Extended MLD Capabilities can be provided in the Common Info field of the Basic Multi-Link element of the Multi-Link element. This field can then be configured to include information equivalent to 504, 514, or 515. This element can be included in MAC frames such as ML Probe Request, ML Probe Response, and Beacon.

[0135] <Other embodiment 1> The disclosure of this embodiment also includes the following configuration.

[0136] (Configuration 1) A communication device that functions as an access point for wireless communication in accordance with the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series, a change means for changing operation from the specific power saving mode to the normal mode in response to receiving a connection request from a station that is not of a specific type when the access point is operating in a specific power saving mode that consumes less power than a normal mode, The specific power saving mode is a mode in which the communication device waits for communication from a station in a state in which at least two or more conditions of the number of communication links, bandwidth, and spatial streams are changed to low-power conditions that are estimated to consume less power than the normal mode, in order to reduce the amount of power consumption when waiting for communication compared to the power consumption when waiting for communication in the normal mode.

[0137] (Configuration 2) 2. The communication device according to configuration 1, wherein the specific type of station is a station that supports wireless communication conforming to the IEEE 802.11bn standard.

[0138] (Configuration 3) The communication device according to configuration 1, wherein the specific type of station is a station that supports wireless communication conforming to the IEEE 802.11bn standard and also supports the specific power saving mode.

[0139] (Configuration 4) The communication device according to any one of configurations 1 to 3, further comprising a communication control means for, when the access point is operating in the specific power saving mode, changing the conditions of at least two or more of the number of communication links, bandwidth, and spatial streams to a second condition that is estimated to have higher power consumption than the low power consumption condition upon receiving an Initial Control Frame, and communicating with the station that transmitted the Initial Control Frame under the changed second condition.

[0140] (Configuration 5) The communication device according to claim 4, characterized in that, upon receiving a Termination Frame, the communication control means changes at least two or more conditions of the number of communication links, bandwidth, and spatial streams to the low power consumption condition, and waits for communication from a station.

[0141] (Configuration 6) 6. The communication device according to configuration 4 or 5, wherein the Initial Control Frame is a frame requesting a return from a specific power saving mode to the second condition.

[0142] (Configuration 7) An AP MLD (Multi-Link Device) having two or more Affiliated APs (Access Points), An AP MLD characterized by having a provision means for configuring one or more first-type Affiliated APs to support a specific power-saving mode that consumes less power than a normal mode, and configuring one or more second-type Affiliated APs not to support the specific power-saving mode, and providing a network to surrounding stations.

[0143] (Configuration 8) The AP MLD according to configuration 7, further comprising a control means for controlling the connection destination of a station when a connection request for establishing a link including at least the first type Affiliated AP is received from a station that is not of a specific type so that the station that is not of a specific type connects to a second type Affiliated AP provided by the AP MLD.

[0144] (Configuration 9) 9. The AP MLD according to configuration 8, wherein the specific type of station is a station that supports wireless communication in accordance with the IEEE (Institute of Electrical and Electronics Engineers) 802.11bn standard.

[0145] (Configuration 10) The AP MLD according to any one of configurations 7 to 9, characterized in that the specific power saving mode is a mode in which at least two or more conditions of the number of communication links, bandwidth, and spatial streams are changed to low power consumption conditions that are estimated to consume less power than the normal mode in order to reduce the amount of power consumption when waiting for communication compared to the power consumption when waiting for communication in the normal mode, and waits for communication from a station.

[0146] (Configuration 11) The AP MLD described in any one of configurations 7 to 9, characterized in that the specific power saving mode is a mode that reduces power consumption by selectively using periods in which the AP provides functions as the second type Affiliated AP and periods in which the AP does not provide functions as the second type Affiliated AP based on a schedule negotiated with the surrounding area, in order to reduce power consumption when waiting for communication compared to power consumption when waiting for communication in the normal mode.

[0147] (Configuration 12) A method for controlling a communication device that functions as an access point for wireless communication in accordance with the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series, comprising: a change step of changing operation from the specific power saving mode to the normal mode in response to receiving a connection request from a station that is not of a specific type when the access point is operating in a specific power saving mode that consumes less power than a normal mode, A control method for a communication device, characterized in that the specific power saving mode is a mode in which at least two or more conditions of the number of communication links, bandwidth, and spatial streams are changed to low power consumption conditions that are estimated to consume less power than the normal mode, in order to reduce the amount of power consumption when waiting for communication compared to the power consumption when waiting for communication in the normal mode, and awaits communication from a station.

[0148] (Configuration 13) 13. A program for causing a computer to execute the method for controlling a communication device according to claim 12.

[0149] (Configuration 14) A control method for an AP MLD (Multi-Link Device) having two or more Affiliated APs (Access Points), An AP MLD control method characterized by comprising a provision step of configuring one or more first-type Affiliated APs to support a specific power-saving mode that consumes less power than a normal mode, and configuring one or more second-type Affiliated APs not to support the specific power-saving mode, thereby providing a network to surrounding stations.

[0150] (Configuration 15) 15. A program for causing a computer to execute the AP MLD control method according to claim 14.

[0151] <Other embodiment 2> The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0152] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0153] 101 AP 102 Station 103 STA 202 Control section 206 Communications Department

Claims

1. A communication device that functions as an access point for wireless communication in accordance with the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series, a change means for changing operation from the specific power saving mode to the normal mode in response to receiving a connection request from a station that is not of a specific type when the access point is operating in a specific power saving mode that consumes less power than a normal mode, The specific power saving mode is a mode in which the communication device waits for communication from a station in a state in which at least two or more conditions of the number of communication links, bandwidth, and spatial streams are changed to low-power conditions that are estimated to consume less power than the normal mode, in order to reduce the amount of power consumption when waiting for communication compared to the power consumption when waiting for communication in the normal mode.

2. 2. The communication device according to claim 1, wherein the specific type of station is a station that supports wireless communication conforming to the IEEE 802.11bn standard.

3. 2. The communication device according to claim 1, wherein the specific type of station is a station that supports wireless communication conforming to the IEEE 802.11bn standard and also supports the specific power saving mode.

4. 2. The communication device according to claim 1, further comprising: communication control means for, when the access point is operating in the specific power saving mode, changing the conditions of at least two or more of the number of communication links, bandwidth, and spatial streams to a second condition that is estimated to have higher power consumption than the low power consumption condition upon receiving an Initial Control Frame, and communicating with the station that transmitted the Initial Control Frame under the changed second condition.

5. 5. The communication device according to claim 4, wherein, upon receiving a Termination Frame, the communication control means changes at least two or more conditions of the number of communication links, bandwidth, and spatial streams to the low power consumption condition, and waits for communication from a station.

6. 5. The communication device according to claim 4, wherein the initial control frame is a frame requesting a return to the second condition from a specific power saving mode.

7. An AP MLD (Multi-Link Device) having two or more Affiliated APs (Access Points), An AP MLD characterized by having a provision means for providing a network to surrounding stations by configuring one or more first-type Affiliated APs to support a specific power-saving mode that consumes less power than a normal mode, and configuring one or more second-type Affiliated APs not to support the specific power-saving mode.

8. 8. The AP MLD according to claim 7, further comprising: a control means for controlling a connection destination of a station so that, when a connection request for establishing a link including at least the first type Affiliated AP is received from a station that is not of a specific type, the station that is not of a specific type connects to a second type Affiliated AP provided by the AP MLD.

9. The AP MLD according to claim 8, wherein the specific type of station is a station that supports wireless communication in accordance with the IEEE (Institute of Electrical and Electronics Engineers) 802.11bn standard.

10. The AP MLD of claim 7, characterized in that the specific power saving mode is a mode in which at least two or more conditions of the number of communication links, bandwidth, and spatial streams are changed to low-power conditions that are estimated to consume less power than the normal mode in order to reduce the amount of power consumption when waiting for communication compared to the power consumption when waiting for communication in the normal mode, and awaits communication from a station.

11. The AP MLD of claim 7, characterized in that the specific power saving mode is a mode that reduces power consumption by selectively using periods in which the AP provides functions as the second type Affiliated AP and periods in which the AP does not provide functions as the second type Affiliated AP based on a schedule negotiated with surrounding devices, in order to reduce power consumption when waiting for communication compared to power consumption when waiting for communication in the normal mode.

12. A method for controlling a communication device that functions as an access point that performs wireless communication in accordance with the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series, comprising: a change step of changing operation from the specific power saving mode to the normal mode in response to receiving a connection request from a station that is not of a specific type when the access point is operating in a specific power saving mode that consumes less power than a normal mode, A control method for a communication device, characterized in that the specific power saving mode is a mode in which at least two or more conditions of the number of communication links, bandwidth, and spatial streams are changed to low power consumption conditions that are estimated to consume less power than the normal mode, in order to reduce the amount of power consumption when waiting for communication compared to the power consumption when waiting for communication in the normal mode, and awaits communication from a station.

13. A program for causing a computer to execute the communication device control method according to claim 12.

14. A control method for an AP MLD (Multi-Link Device) having two or more Affiliated APs (Access Points), comprising: A control method for AP MLD, characterized by comprising a provision step of configuring one or more first-type Affiliated APs to support a specific power-saving mode that consumes less power compared to a normal mode, and configuring one or more second-type Affiliated APs not to support the specific power-saving mode, thereby providing a network to surrounding stations.

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

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