Communication device, control method thereof, and program

Abstract

To allow a communication device that performs multilink communication to more efficiently collect power saving information related to a power saving operation in an opposite device.SOLUTION: A communication device is used for wireless communication conforming to IEEE 802.11 series standards and establishes a plurality of wireless links used for data communication with an opposite device. The communication device collects, from the opposite device, power saving information related to power saving operations corresponding to the plurality of respective wireless links in the opposite device. At that time, the communication device collects the power saving information from the opposite device by using a wireless link that is in an effective state among the plurality of wireless links before stating frame exchange for next data communication with the opposite device.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a communication device that performs data communication using a plurality of wireless links, a control method for the same, and a program. [Background technology]

[0002] The IEEE802.11 series of standards is known as a wireless local area network (wireless LAN or WLAN) communication standard formulated by the IEEE (Institute of Electrical and Electronics Engineers). The IEEE802.11 series of standards includes the IEEE802.11a / b / g / n / ac / ax standards. IEEE is currently considering formulating the IEEE802.11be standard to further improve throughput and frequency utilization efficiency.

[0003] The introduction of multi-link transmission technology is being considered for the IEEE802.11be standard (Non-Patent Document 1). Multi-link transmission technology is a technology in which a communication device (multi-link device (MLD)) on one access point (AP) side communicates with a communication device (MLD) on one station (STA) side by establishing multiple links via multiple different frequency channels.

[0004] In connection with the standardization of the IEEE802.11be standard, a method is being considered for communication devices to notify each other of information related to power-saving operations corresponding to wireless links that are switched from disabled links to enabled links using a TID-mapping update (Non-Patent Document 2). Note that an enabled link is a wireless link in a state where frame exchange is possible, and an disabled link is a wireless link in a state where frame exchange is not possible. STAs that support multi-link communication support power-saving modes according to the state of the wireless link. The time required for the wireless hardware unit of the STA to return from power-saving mode and become able to exchange frames varies depending on the power-saving level of the STA. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Yasuhiko Inoue and Akira Kishida, "Latest Trends in Next-Generation Wireless LAN Standardization in the IEEE 802.11 Working Group," NTT Technical Journal, Vol. 32, No. 12, December 2020. [Non-patent document 2] MediaTek Inc., "Link Enablement Considerations," IEEE 802.11-20 / 0280r2, March 8, 2020. Summary of the Invention [Problem to be solved by the invention]

[0006] If the wireless link corresponding to the STA that requires a long time is selected as the wireless link to be used for frame exchange for the next data communication, the time required for the STA to return from the power saving mode (to switch the wireless link back to the active state) may be long, which may result in failure or delay in data transmission from the communication device on the AP side to the communication device on the STA side.

[0007] In addition, in the above process, in order for the communication device on the AP side to collect power-saving information related to the power-saving operation of the STA corresponding to each wireless link, each wireless link is temporarily switched to an active link using a TID map update. In this case, even wireless links not used for data communication are switched to an active state only for the purpose of collecting (notifying) power-saving information, which may cause the STA to return from power-saving mode. As a result, the communication device on the STA side cannot sufficiently perform power saving.

[0008] Therefore, an object of the present invention is to provide a technique that enables a communication device that performs multi-link communication to more efficiently collect power-saving information related to the power-saving operation of a partner device. [Means for solving the problem]

[0009] A communication device according to one aspect of the present invention comprises: A communication device that performs multi-link communication using a plurality of links conforming to the IEEE 802.11 series of standards, the communication device having a first STA (Station) and a second STA that establish the plurality of links, includes a receiving means for receiving a first frame transmitted by the first STA, the first frame received by the receiving means does not include information on the power management mode of the first STA, but includes information on the power management mode of the second STA. It is characterized by:

[0010] Furthermore, a communication device according to another aspect of the present invention includes: A communication device that performs multi-link communication using a plurality of links conforming to the IEEE802.11 series of standards, the device comprising a first STA and a second STA that establish the plurality of links, and a transmitting means that transmits a first frame to another communication device using the first STA, the first frame transmitted by the transmitting means not including information on the power management mode of the first STA but including information on the power management mode of the second STA. It is characterized by: [Effects of the Invention]

[0011] According to the present invention, a communication device that performs multi-link communication can more efficiently collect power-saving information related to the power-saving operation of a partner device. [Brief explanation of the drawings]

[0012] [Figure 1] Diagram showing an example of a network configuration [Figure 2] A block diagram showing an example of the hardware configuration of a communication device. [Figure 3] Block diagram showing an example of the functional configuration of a communication device (AP-MLD) [Figure 4] Block diagram showing an example of the functional configuration of a communication device (Non-AP MLD) [Figure 5]1 is a flowchart showing a processing procedure performed by a communication device (AP-MLD). [Figure 6] Flowchart showing the procedure of processing by a communication device (Non-AP MLD) [Figure 7] FIG. 1 is a diagram showing an example of the state of multiple wireless links and frame exchanges between communication devices. [Figure 8] FIG. 1 is a diagram showing an example of the state of multiple wireless links and frame exchanges between communication devices. [Figure 9] FIG. 1 is a diagram showing an example of the state of multiple wireless links and frame exchanges between communication devices. [Figure 10] FIG. 1 is a diagram showing an example of the state of multiple wireless links and frame exchanges between communication devices. [Figure 11] FIG. 10 is a diagram showing an example of the state of multiple wireless links and frame exchange between communication devices (second embodiment); [Figure 12] FIG. 10 is a diagram illustrating a comparison example of the state of multiple wireless links and frame exchange between communication devices. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe multiple features, 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.

[0014] <Network configuration> 1 shows an example of the configuration of a network in which communication devices 102 and 103 according to this embodiment participate. In this example, the network 101 is a wireless network, and the communication devices 102 and 103 participate in the network 101.

[0015] The communication device 102 is an access point (AP) that serves to establish the network 101. In this embodiment, when the communication device 102 establishes multiple networks, the networks share a common BSSID (Basic Service Set Identifier) ​​and a common SSID (Service Set Identifier) ​​is used in each network. The BSSID is an identifier for identifying a network, and the SSID is an identifier for identifying an AP. In this embodiment, the communication device 102 uses one SSID even when multiple connections are established. The communication device 103 is a station (STA) that serves to participate in the network 101 established by the AP (communication device 102). Note that while FIG. 1 illustrates a network configured with one AP and one STA, the number of APs and the number of STAs are not limited to this.

[0016] Each communication device is compatible with the IEEE802.11be (EHT: Extremely High Throughput or Extreme High Throughput) standard as a wireless LAN communication standard, and is capable of performing wireless communication in accordance with the IEEE802.11be standard. Each communication device is configured to be able to perform wireless communication in multiple frequency bands (in this embodiment, the 2.4 GHz band, the 5 GHz band, and the 6 GHz band). The frequency bands that each communication device can use are not limited to these, and each communication device may be able to use a different frequency, such as the 60 GHz band. Each communication device is configured to be able to communicate using bandwidths such as 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz.

[0017] The communication devices 102 and 103 can realize multi-user (MU) communication by performing OFDMA (Orthogonal Frequency Division Multiple Access) communication conforming to the IEEE 802.11be standard. Multi-user communication is communication in which signals from multiple users are multiplexed. In OFDMA communication, frequency resources are assigned to each STA so that parts of the divided frequency band (RUs: Resource Units) do not overlap between the STAs, and the frequency resources (carriers) assigned to each STA are orthogonal to each other. Therefore, the AP (communication device 102) can communicate with multiple STAs (communication device 103) in parallel (simultaneously).

[0018] In this embodiment, the communication devices 102 and 103 are compliant with the IEEE 802.11be standard, but may also be compliant with at least one legacy standard that predates the IEEE 802.11be standard. The legacy standard is the IEEE 802.11a / b / g / n / ac / ax standard. In this embodiment, at least one of the IEEE 802.11a / b / g / n / ac / ax / be standards is referred to as an IEEE 802.11 series standard.

[0019] Furthermore, the communication devices 102 and 103 may support other communication standards such as Bluetooth (registered trademark), NFC (Near Field Communication), UWB (Ultra Wide Band), Zigbee, and MBOA (Multi Band OFDM Alliance) in addition to the IEEE802.11 series standards. UWB includes wireless USB, wireless 1394, Winet, etc. Furthermore, the communication devices 102 and 103 may also support a communication standard for wired communication such as a wired LAN.

[0020] <Multi-link communication> The communication devices 102 and 103 are multilink devices (MLDs) that have the function of performing multilink communication, which establishes and communicates through multiple links (transmission paths) via multiple frequency channels. In multilink communication, multiple links are established and used between an AP MLD equipped with multiple APs and a Non-AP MLD (STA MLD) equipped with multiple STAs. In this embodiment, the communication device 102 operates as an AP MLD, and the communication device 103 operates as a Non-AP MLD. FIG. 1 shows an example in which three links (link 1, link 2, and link 3) are established in parallel between the communication device 102 and the communication device 103.

[0021] In multi-link communication, multiple links established between the communication device 102 and the communication device 103 are established on different frequency channels. Furthermore, the channel spacing between the frequency channels on which the multiple links are established can be at least greater than 20 MHz. Here, the frequency channel refers to a frequency channel defined in the IEEE 802.11 series of standards, and refers to a frequency channel on which wireless communication compliant with the IEEE 802.11 series of standards can be performed. The IEEE 802.11 series of standards defines multiple frequency channels in each of the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. Furthermore, the IEEE 802.11 series of standards defines the bandwidth of each frequency channel as 20 MHz. Note that a single frequency channel may be bonded with an adjacent frequency channel to utilize a bandwidth of 40 MHz or more.

[0022] For example, as shown in FIG. 1 , the communication device 102 (AP MLD) establishes, with the communication device 103 (Non-AP MLD), link 1 via a first frequency channel in the 2.4 GHz band and link 2 via a second frequency channel in the 5 GHz band. This allows the communication device 102 to communicate with the communication device 103 via both link 1 and link 2. In this case, the communication device 102 maintains link 2 via the second frequency channel in parallel with link 1 via the first frequency channel. In this way, the communication device 102 can improve the throughput of communication with the communication device 103 by establishing multiple links with the communication device 103 via multiple frequency channels, respectively.

[0023] In multi-link communication, the communication devices 102 and 103 may establish multiple links via different frequency bands. For example, the communication devices 102 and 103 may establish link 1 in the 2.4 GHz band, link 2 in the 5 GHz band, and link 3 in the 6 GHz band. Alternatively, the communication devices 102 and 103 may establish multiple links via different channels included in the same frequency band. For example, the communication devices 102 and 103 may establish link 1 via channel 1 in the 2.4 GHz band and link 2 via channel 5 in the 2.4 GHz band.

[0024] Furthermore, multiple links in the same frequency band and links in different frequency bands may coexist in the multi-link communication between the communication devices 102 and 103. For example, the communication devices 102 and 103 may establish a link 3 via channel 36 (36) in the 5 GHz band in addition to a link 1 via channel 1 and a link 2 via channel 5 in the 2.4 GHz band.

[0025] In this way, by establishing multiple connections with the communication device 103, each using a different frequency band, the communication device 102 can communicate with the communication device 103 using another band, even if one band is congested. This makes it possible to prevent a decrease in throughput in communication between the communication device 102 and the communication device 103.

[0026] When performing multi-link communication, the communication devices 102 and 103 divide a single piece of data and transmit it to a partner device via multiple links. Alternatively, the communication devices 102 and 103 may transmit the same data in parallel via multiple links, thereby using communication via one link as a backup communication for communication via another link. Specifically, consider a case in which the communication device 102 transmits the same data to the communication device 103 via link 1 via a first frequency channel and link 2 via a second frequency channel. In this case, even if an error occurs in communication via link 1, the communication device 103 can receive the data transmitted from the communication device 102 because the same data is transmitted via link 2.

[0027] Alternatively, the communication devices 102 and 103 may use different links depending on the type of frame and the type of data to be transmitted. For example, the communication device 102 may transmit management frames via link 1 and transmit data frames containing data via link 2. Note that management frames specifically refer to beacon frames, probe request / response frames, and association request / response frames. In addition to these frames, disassociation frames, authentication frames, de-authentication frames, and action frames are also referred to as management frames.

[0028] Specifically, each of the above management frames is as follows: ●Beacon frames are frames used to announce network information. A Probe Request frame is a frame for requesting network information. A Probe Response frame is a response to a Probe Request frame and is a frame for providing network information. ●An Association Request frame is a frame for requesting a connection. An Association Response frame is a response to an Association Request frame, and indicates permission for connection or an error. ●The Disassociation frame is a frame for disconnecting a connection. The Authentication frame is a frame for authenticating the other device. The De-Authentication frame is a frame for interrupting authentication of the remote device and disconnecting the connection. The Action frame is a frame for executing additional functions other than those mentioned above.

[0029] In this way, the communication devices 102 and 103 transmit and receive management frames that comply with the IEEE802.11be standard (IEEE802.11 series standards). Furthermore, when transmitting data related to a captured image, for example, the communication device 102 may transmit meta-information such as the date, parameters at the time of capture (aperture value and shutter speed), and location information via link 1, and pixel information via link 2.

[0030] Furthermore, the communication devices 102 and 103 may be capable of performing MIMO (Multiple-Input And Multiple-Output) communication. In this case, the communication devices 102 and 103 each have multiple antennas. The transmitting communication device transmits different stream signals from each antenna using the same frequency channel. The receiving communication device simultaneously receives all the multiple stream signals using multiple antennas, and separates and decodes the signals of each stream. In this way, by performing MIMO communication, the communication devices 102 and 103 can transmit and receive more data in the same time period than when not performing MIMO communication. Furthermore, when performing multi-link communication, the communication devices 102 and 103 may perform MIMO communication on some of the links.

[0031] The communication devices 102 and 103 may be any communication device capable of performing multi-link communication with other communication devices. The communication device 102 may be, for example, but is not limited to, a wireless LAN router or a PC. The communication device 103 may be, for example, but is not limited to, a camera, a tablet, a smartphone, a PC, a mobile phone, or a video camera. The communication devices 102 and 103 may also be information processing devices equipped with a wireless chip or the like capable of performing wireless communication in accordance with the IEEE802.11be standard. Note that the information processing device equipped with the wireless chip has an antenna for transmitting the generated signal.

[0032] <Hardware Configuration of Communication Device 102> 2 is a block diagram showing an example of the hardware configuration of the communication device 102 in this embodiment. The communication device 102 has a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207. Note that the communication device 103 may have the same hardware configuration as the communication device 102.

[0033] The storage unit 201 is configured with one or more memories such as a ROM (Read Only Memory) and / or a RAM (Random Access Memory). The storage unit 201 stores computer programs for performing various operations described below, and various information such as communication parameters for wireless communication. Note that other types of storage media such as a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, and a DVD may be used as the one or more memories constituting the storage unit 201. The storage unit 201 may also include multiple memories.

[0034] The control unit 202 is configured with one or more processors, such as a CPU (Central Processing Unit) and / or an MPU (Micro Processing Unit). The control unit 202 controls the entire communication device 102 by reading and executing a computer program stored in the storage unit 201. The control unit 202 may be configured to control the entire communication device 102 in cooperation with the computer program and an OS (Operating System) stored in the storage unit 201. The control unit 202 may also be configured to include multiple processors, such as a multi-core processor, and to control the entire communication device 102 using the multiple processors.

[0035] The control unit 202 generates data or signals (wireless frames) to be transmitted in communication with other communication devices. The control unit 202 further controls the function unit 203 to execute predetermined processes such as wireless communication, imaging, printing, and projection. The function unit 203 is hardware that enables the communication device 102 to execute predetermined processes.

[0036] The input unit 204 receives various operations from the user. The output unit 205 outputs various types of information to the user via a monitor screen or a speaker. Here, the output from the output unit 205 may be one or more of a display on a monitor screen, an audio output from a speaker, a vibration output, and the like. The input unit 204 and the output unit 205 may be realized as a single module, such as a touch panel display. Furthermore, the input unit 204 and the output unit 205 may each be configured integrally with the communication device 102, or may be provided separately from the communication device 102.

[0037] The communication unit 206 controls wireless communication in accordance with the IEEE802.11be standard, etc. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202. The communication device 102 transmits and receives various data such as image data, document data, and video data by communicating with the communication device 103 via the communication unit 206.

[0038] The communication unit 206 may be configured to control wireless communications compliant with other IEEE 802.11 series standards in addition to the IEEE 802.11be standard, and to control wired communications such as a wired LAN. If the communication device 102 supports the NFC standard, the Bluetooth standard, or the like in addition to the IEEE 802.11be standard, it may also be configured to control wireless communications compliant with these communication standards. If the communication device 102 is configured to be able to perform wireless communications compliant with multiple communication standards, it may have individual communication units and antennas corresponding to the different communication standards.

[0039] The antenna 207 is an antenna capable of communication in a predetermined frequency band (in this embodiment, the 2.4 GHz band, the 5 GHz band, and the 6 GHz band). The communication device 102 in the embodiment has one antenna, but may have a separate antenna for each frequency band. Furthermore, if the communication device 102 has multiple antennas, it may have a corresponding communication unit 206 for each antenna. Note that the antenna 207 may be provided separately from the communication unit 206 as shown in FIG. 2, or may be configured together with the communication unit 206 as a single module.

[0040] <Functional Configuration of Communication Device 102> 3 is a block diagram showing an example of the functional configuration of the communication device 102. The communication device 102 has, as functional units, a link connection unit 301, a frame generation unit 302, a data transmission / reception unit 303, an information collection unit 304, a required time acquisition unit 305, and a link selection unit 306.

[0041] The link connection unit 301 performs connection processing to establish one or more links used by the communication device 102 for data communication with the communication device 103. The connection processing specifically includes authentication processing, association processing, and 4-Way Handshake (4WHS) processing. Upon completion of the 4WHS processing, a PTK, which is an encryption key for unicast communication, and a GTK, which is an encryption key for broadcast communication and multicast communication, are generated in the communication device 102 and the communication device 103, respectively. When connecting with the communication device 103, the link connection unit 301 may connect multiple links in advance, or may connect another link later during communication via a predetermined link.

[0042] The information collection unit 304 collects power saving information from each of a plurality of STAs that use a multilink (e.g., links 1 to 3 in FIG. 1 ) established with the communication device 103 (Non-AP MLD). The collected power saving information is information indicating, for example, a hardware recovery time (Transition delay), a power management (PM) mode, and a power state. The hardware recovery time is the time required for a corresponding STA among the plurality of STAs (communication units) to recover from a power saving state such as a doze state and become capable of frame exchange. The power management mode (PM mode) is used when a corresponding wireless link among the plurality of wireless links is in an active state, and is either an active mode or a power save (PS) mode. The power state is the power state of the corresponding STA among the plurality of STAs (communication units), and is either an awake state or a doze state.

[0043] The required time acquisition unit 305 acquires (calculates) the time required for each STA to be able to exchange data using its hardware, based on the power saving information. The link selection unit 306 selects a wireless link to be used for frame exchange for the next data transmission, based on the result acquired by the required time acquisition unit 305.

[0044] The frame generation unit 302 generates MAC frames including management frames such as authentication requests or association requests, and data frames. The data transmission / reception unit 303 transmits wireless frames including the MAC frames generated by the frame generation unit 302, and receives wireless frames from other devices.

[0045] <Functional configuration of communication device 103> 4 shows the functional configuration of the communication device 103 in this embodiment. The communication device 103 has, as functional units, a link connection unit 401, a frame generation unit 402, a data transmission / reception unit 403, and a power saving information notification unit 404. The link connection unit 401, the frame generation unit 402, and the data transmission / reception unit 403 have the same functions as the link connection unit 301, the frame generation unit 302, and the data transmission / reception unit 303 of the communication device 102, respectively.

[0046] The power saving information notification unit 404 notifies the communication device 103 of the power saving information (transmits a notification including the power saving information) in response to an inquiry from the communication device 102 or according to a predetermined condition. This predetermined condition is, for example, that the power saving information (hardware recovery time, power management mode, power state, etc.) of the communication device 103 itself has been updated.

[0047] <Comparative Example> Fig. 12 shows a comparative example of the states of multiple wireless links and frame exchange between communication devices, and shows a comparative example to the processing described later using Figs. 5 to 10. As shown in Fig. 12, in this comparative example, links 1 to 3 are established as multiple wireless links used for data communication between communication device 1 (AP MLD) and communication device 2 (Non-AP MLD). Communication device 1 has AP1 to AP3 as multiple communication units, and communication device 2 has STA1 to STA3 as multiple communication units. Link 1 is established between AP1 and STA1, link 2 is established between AP2 and STA2, and link 3 is established between AP3 and STA3.

[0048] As will be described later, each wireless link can be switched between an enabled link state, in which frame exchange via the wireless link is possible, and a disabled link state, in which frame exchange via the wireless link is impossible. A traffic identifier (TID) mapping update is used to switch each wireless link between the enabled state (enabled link) and the disabled state (disabled link). Specifically, the state of each wireless link is switched using a message (hereinafter referred to as a TID map update message) containing TID-mapping update (or TID-Map Update) information transmitted from communication device 1 to communication device 2.

[0049] In this comparative example, for each of the multiple wireless links (links 1 to 3), power saving information is notified from the communication device 2 (STA side) to the communication device 1 (AP side) at the timing of switching to the valid state by the TID map update message. Note that this power saving information may include information indicating the hardware recovery time (Transition delay), power management mode (PM mode), and power state (Power State) for the corresponding STA, as described above.

[0050] Specifically, by transmitting TID map update message 1201 from communication device 1 to communication device 2, the states of links 1 and 3 are switched from disabled to enabled, in addition to link 2, which is already enabled. In response to this, communication device 2 transmits notification 1202 including operation parameters (power saving information) to communication device 1. Thereafter, communication device 1 selects a wireless link to be used for data communication (link 1 in this example) based on the acquired power saving information, and uses TID map update message 1203 to enable the selected wireless link and disable the other wireless links.

[0051] In this way, when switching a wireless link from an invalid state to an valid state, it takes a few nanoseconds to 100 milliseconds for the corresponding STA in the communication device 2 to recover (start up) from the power-saving state, depending on the power-saving level of the STA (hardware). Therefore, if a wireless link corresponding to a STA with a long hardware recovery time is selected as the wireless link to be used for data communication, it may take a long time for the STA to recover from the power-saving state (switch the wireless link to the valid state). This may result in a failure or delay in data transmission from the communication device (communication device 1) on the AP side to the communication device (communication device 2) on the STA side.

[0052] Furthermore, a wireless link not used for data communication (link 3 in the example of FIG. 12) is also switched to an enabled state for collecting (notifying) power-saving information, causing the corresponding STA in the communication device 2 to transition from a doze state (power-saving state) to an awake state. This makes it impossible to achieve sufficient power saving in the communication device 2.

[0053] Therefore, in this embodiment, the process described below enables the communication device 103 performing multi-link communication to more efficiently collect power saving information related to the power saving operation of the opposing device (communication device 102).

[0054] <Power saving information collection and notification processing> In this embodiment, the communication device 102 (AP MLD) establishes multiple wireless links used for data communication with the communication device 103 (Non-AP MLD), which is the opposing device, and performs multi-link communication using the multiple established wireless links with the communication device 103. The state of each established wireless link can be switched between an enable link state (enabled state) in which frame exchange via the wireless link is possible, and a disable link state (disabled state) in which frame exchange via the wireless link is not possible.

[0055] The communication device 102 collects (obtains) power-saving information related to power-saving operations corresponding to each of a plurality of wireless links in an opposite device (communication device 103) from the opposite device. The communication device 102 collects the power-saving information from the opposite device using a wireless link (active link) that is in an active state among the plurality of wireless links before starting frame exchange for the next data communication with the opposite device. At this time, the communication device 102 can collect the power-saving information from the opposite device using a wireless link that is in an active state among the plurality of wireless links, without switching an inactive wireless link to an active state. Unlike the comparative example described above, wireless links that are not used for data communication are not switched to an active state solely for the purpose of collecting (notifying) power-saving information, and this makes it possible to sufficiently save power in the communication device 103.

[0056] Furthermore, based on the collected power saving information, the communication device 102 selects (determines) one or more wireless links to be used for frame exchange for the next data communication with the opposite device (communication device 103) from among the multiple wireless links with the opposite device. Thereafter, the communication device 102 activates the one or more selected wireless links and exchanges frames for data communication with the opposite device using the one or more wireless links.

[0057] The power saving information collection process by the communication device 102 and the power saving information notification process by the communication device 103 will be described in more detail below with reference to FIGS.

[0058] Fig. 5 is a flowchart showing the procedure of processing executed by communication device 102. Fig. 6 is a flowchart showing the procedure of processing executed by communication device 103 corresponding to the processing of communication device 102 shown in Fig. 5. Figs. 7 to 10 show different examples of the states of multiple wireless links and frame exchanges between communication device 102 and communication device 103.

[0059] 7 to 10, a multi-link setup process (establishment process) is performed between the communication device 102 and the communication device 103, and three wireless links (links 1 to 3) are established. The communication devices 102 and 103 each have a plurality of communication units (wireless communication interfaces) that perform wireless communication with a counterpart device using the corresponding wireless links. In this example, the communication device 102 has AP1 to AP3 as the plurality of communication units 206, and the communication device 103 has STA1 to STA3 as the plurality of communication units. Link 1 is established between AP1 and STA1, link 2 is established between AP2 and STA2, and link 3 is established between AP3 and STA3. Links 1 to 3 perform wireless communication via a first frequency channel (e.g., channel 1 in the 2.4 GHz band), a second frequency channel (e.g., channel 36 in the 5 GHz band), and a third frequency channel (e.g., a channel in the 6 GHz band), respectively.

[0060] 7 to 10, in this example, only link 2 is in an enabled state where frame exchange is possible, and links 1 and 3 are in an disabled state where frame exchange is not possible. In this case, as will be described below, communication device 102 uses link 2 to collect (acquire) power saving information from communication device 103, and selects one or more wireless links to be used for frame exchange for the next data communication based on the acquired power saving information. FIG. 7 shows an example where link 2 is selected, FIGS. 8 and 9 show examples where link 1 is selected, and FIG. 10 shows an example where links 1 and 3 are selected.

[0061] <Communication device (AP MLD) processing procedure> The processing (FIG. 5) by the communication device 102 (AP MLD) will be described with appropriate reference to the examples of FIGS. 7 to 10. Note that the processing of each step in FIG.

[0062] First, in S501, the communication device 102 transmits a request message 701 to the communication device 103 (opposing device) requesting power saving information related to power saving operations corresponding to each of a plurality of established links in the communication device 103. In the examples of Figures 7 to 10, since link 2 is in an enabled state, the communication device 102 transmits the request message 701 using link 2.

[0063] Next, in S502, the communication device 102 determines whether or not power saving information has been collected from the communication device 103. The communication device 102 receives a response message 702 in response to the request message 701 from the communication device 103 using an active wireless link (link 2 in this example), and collects power saving information from the received response message. For example, the response message includes power saving information corresponding to all of the multiple established links. In this way, of the multiple wireless links established between the communication devices, power saving information corresponding to inactive wireless links (links 1 and 3 in this example) is collected (notified) using an active wireless link (link 2 in this example). If the communication device 102 has collected power saving information from the communication device 103, the process proceeds to S503.

[0064] 7 to 10, the response message 702 contains power saving information corresponding to the disabled links 1 and 3, and includes power saving information related to the power saving operation of STA1 and 3 in the communication device 103 (opposite device). The power saving information includes information indicating that the hardware transition delay for STA1 (link 1) is 10 ms and that the power state is a doze state. The power saving information also includes information indicating that the hardware transition delay for STA3 (link 3) is 100 ms and that the power state is a doze state.

[0065] As will be described later, the communication device 102 may acquire power saving information from the communication device 103 (for example, periodically) while exchanging frames for data communication with the communication device 103. Furthermore, the communication device 103 may autonomously notify the communication device 102 of power saving information (for example, periodically).

[0066] In S503, the communication device 102 acquires the time required until frame exchange for the next data communication with the communication device 103 (opposing device) can be started when using each wireless link, based on the collected power saving information corresponding to each STA (each link). The communication device 102 may calculate the required time based on, for example, the hardware recovery time included in the power saving information.

[0067] In S504, the communication device 102 selects one or more wireless links from the plurality of wireless links (links 1 to 3) to be used for frame exchange for the next data communication with the communication device 103, based on the required time corresponding to each wireless link acquired in S503. That is, the communication device 102 selects one or more STAs suitable for the next data communication from STAs 1 to 3 of the communication device 103, and selects one or more corresponding wireless links. In this way, one or more target links to be used for the next data communication (data transmission and reception) are determined.

[0068] As examples of wireless link selection in S504, link 2 is selected in the example of Fig. 7, link 1 is selected in the examples of Fig. 8 and Fig. 9, and links 1 and 3 are selected in the example of Fig. 10. As a result of the wireless link selection in S504, data communication is performed using a single link in the examples of Fig. 7 to Fig. 9, and data communication is performed using multiple links in the example of Fig. 10. Note that if link 2, which is currently in an active state, is selected, link 2 will remain in an active state and will also be used in the next data communication.

[0069] Next, in S505, the communication device 102 transmits a TID map update message to the communication device 103 as needed, depending on the result of the wireless link selection in S504. In the examples of Figures 7 to 10, the TID map update message 703 is transmitted as follows:

[0070] In the example of FIG. 7, the communication device 102 has decided to use link 2 in the next data communication. Therefore, the communication device 102 transmits a TID map update message 703 in which information about link 2 is enabled and information about links 1 and 3 is disabled. In this example, because link 2 continues to be used and links 1 and 3 remain disabled, there is no need to change the status of all of the multiple links (links 1 to 3) when the next data communication starts. In such a case, the communication device 102 does not need to transmit a TID map update message. In other words, the communication device 102 may transmit a TID map update message only when a state change is required for one or more of the multiple established links.

[0071] 8, the communication device 102 has decided to use link 1 for the next data communication. Therefore, the communication device 102 transmits a TID map update message 703 in which information about link 1 is enabled and information about links 2 and 3 is disabled.

[0072] 9, similar to the example of Fig. 8, communication device 102 determines to use link 1 for the next data communication. However, communication device 102 transmits TID map update message 703 that enables information about not only link 1 but also link 2 so that link 2, which had been used until then, remains enabled while data communication using link 1 is being performed.

[0073] 10, the communication device 102 has decided to use links 1 and 3 for the next data communication. Therefore, the communication device 102 transmits a TID map update message 703 in which information about links 1 and 3 is enabled and information about link 2 is disabled.

[0074] TID maps as needed update After transmitting the message to the communication device 103, the communication device 102 proceeds to S506. In S506, the communication device 102 performs processing to enable the wireless link (target link) to be used for the next data communication and disable other wireless links that will not be used. Note that when the communication device 102 excludes the wireless link that has been used up until then (link 2 in the examples of FIGS. 7 to 10) from the target links, the communication device 102 may maintain the wireless link (link 2) in an enabled state, as in the example of FIG. 9. Upon completion of the processing of S506, in S507, the communication device 102 executes frame exchange for data communication with the communication device 103 using the enabled target link, and ends the processing according to the procedure of FIG. 5. In the examples of FIGS. 7 to 10, link control and data communication are performed as follows.

[0075] 7, the communication device 102 determines to continue using link 2 for the next data communication. In this case, the communication device 102 continues to keep link 2 enabled and links 1 and 3 disabled, and exchanges frames for data communication using link 2.

[0076] 8, the communication device 102 determines to use link 1 for the next data communication. In this case, the communication device 102 switches link 1 from an invalid state to an valid state, switches link 2 from an valid state to an invalid state, keeps link 3 in the invalid state, and exchanges frames for data communication using link 2. In response to switching link 2 to the invalid state (invalid link), the communication device 103 transitions the power state of the corresponding STA2 to a doze state, which has a higher power saving effect.

[0077] In the example of FIG. 9, similar to the example of FIG. 8, the communication device 102 determines to use link 1 for the next data communication. However, unlike the example of FIG. 8, link 2, which had been used until then, is maintained in an active state while data communication using link 1 is being performed. In this case, the communication device 103 sets the power management mode of STA2 corresponding to link 2 to active mode or power save (PS) mode, and transitions the power state to awake state or doze state. In this way, by performing power saving operation of STA2 while maintaining link 2, which is not used for data communication, in the communication device 103, it is possible to reduce power consumption in the communication device 103.

[0078] 10, the communication device 102 determines to use two wireless links, links 1 and 3, in the next data communication. In this case, the communication device 102 switches links 1 and 3 from an invalid state to an valid state, switches link 2 from an valid state to an invalid state, and exchanges frames for data communication using links 1 and 3.

[0079] <Communication device (Non-AP MLD) processing procedure> The communication device 103 of this embodiment transmits power saving information relating to power saving operations corresponding to each of a plurality of established links to the opposite device (communication device 102) before starting frame exchange for the next data communication with the opposite device. Device Notify the.

[0080] Hereinafter, the processing (FIG. 6) executed by the communication device 103 (Non-AP MLD) in response to the processing of the communication device 102 shown in FIG. 5 will be described with reference to the examples of FIGS. 7 to 10 as needed.

[0081] First, in S601, the communication device 103 determines whether or not a request message for power saving information (transmitted from the communication device 102 in S501) has been received using an active wireless link, and if a request message has been received, the process proceeds to S602. In S602, the communication device 103 transmits to the communication device 102, as a response message to the received request message, a response message including power saving information related to power saving operations corresponding to each of the multiple established links in the communication device 103 itself.

[0082] In the examples of FIGS. 7 to 10, the communication device 103 receives a request message 701 from the communication device 102 using link 2 in an active state, and transmits a response message 702 to the communication device 102. At that time, the communication device 103 includes in the response message 702 at least the power saving information corresponding to the disabled wireless links (links 1 and 3 in this example). In other words, the power saving information corresponding to link 2 (power saving information related to the power saving operation of STA2) does not have to be included in the response message 702. The communication device 103 receives a request message 701 from the communication device 102 using link 2 in an active state, and transmits a response message 702 to the communication device 102. - If notification to the communication device 102 is required, such as when the hardware recovery time is changed, power saving information corresponding to all of the multiple established links, including the power saving information corresponding to link 2, may be included.

[0083] After transmitting the response message, in S603, the communication device 103 starts a receive timer. The receive timer is used to wait until a TID map update message (S505) transmitted from the communication device 102 is received. In S604, the communication device 103 determines whether the receive timer has timed out, thereby determining whether a TID map update message has been received from the communication device 102 within a predetermined time via an active link (link 2 in this example). If the receive timer has timed out (expired) (i.e., the communication device 103 has not received a TID map update message within the predetermined time), the communication device 103 terminates the processing according to the procedure in FIG. 6. In this case, the communication device 103 continues to use the active wireless link (link 2 in this example) currently being used for the frame exchange with the communication device 102 for the next data communication.

[0084] On the other hand, if communication device 103 receives a TID map update message from communication device 102 before the reception timer times out (expires) (i.e., within a predetermined time) (“YES” in S605), communication device 103 proceeds to S606. In S606, communication device 103 analyzes the received TID map update message and determines one or more wireless links to use for the next data communication based on the analysis result and the current usage status of the multiple established wireless links (links 1 to 3).

[0085] Thereafter, in S607, the communication device 103 performs processing to enable the wireless link (target link) to be used for the next data communication and disable other wireless links that will not be used. Upon completion of the processing of S607, in S608, the communication device 103 executes frame exchange for data communication with the communication device 102 (opposing device) using the enabled target link, and ends the processing according to the procedure in Fig. 6. In the examples of Figs. 7 to 10, link control and data communication are performed as described above in relation to the processing of the communication device 102.

[0086] As described above, the communication device 102 of this embodiment is used for wireless communication conforming to the IEEE 802.11 series standards, and establishes multiple wireless links (links 1 to 3) used for data communication with a counterpart device (communication device 103). The communication device 102 collects (obtains) power-saving information related to power-saving operations corresponding to each of the multiple wireless links from the counterpart device. In this case, the communication device 102 collects the power-saving information from the counterpart device using a wireless link (active link) that is in an active state among the multiple wireless links before starting frame exchange for the next data communication with the counterpart device.

[0087] The communication device 103 of this embodiment is used for wireless communication conforming to the IEEE802.11 series standard, and establishes a plurality of wireless links (links 1 to 3) used for data communication with a counterpart device (communication device 102). The communication device 103 notifies the counterpart device of power saving information related to the power saving operation corresponding to each of the plurality of wireless links in the communication device itself. At this time, the communication device 103 notifies the counterpart device of the power saving information. notification This is performed using a wireless link that is in an active state (active link) among the multiple wireless links before starting frame exchange for the next data communication with the opposite device.

[0088] According to this embodiment, the communication device 102 can collect power saving information corresponding to an inactive wireless link before starting frame exchange for the next data communication with the opposite device. This makes it possible to more appropriately select a wireless link to be used for data communication depending on the power saving state of the corresponding STA. As a result, it becomes possible to avoid failures or delays in data transmission from the communication device 102 on the AP side to the communication device 103 on the STA side. Furthermore, it becomes unnecessary to switch a wireless link not used for data communication to an active state solely for the purpose of collecting (notifying) power saving information, and it becomes possible to sufficiently save power in the communication device 103. As such, according to this embodiment, the communication device 102 performing multi-link communication can more efficiently collect power saving information related to the power saving operation of the opposite device (communication device 103).

[0089] [Second embodiment] The first embodiment describes an example in which the communication device 102 (AP MLD) transmits a request message to the communication device 103 (Non-AP MLD) to collect power saving information from the communication device 103. The second embodiment describes another example of the power saving information collection process by the communication device 102 and the power saving information notification process by the communication device 103. The following mainly describes the differences from the first embodiment.

[0090] 11 shows an example of the states of multiple wireless links and frame exchange between the communication device 102 and the communication device 103 according to this embodiment. In the example of FIG. 11, similar to the examples of FIGS. 7 to 10 in the first embodiment, a multi-link setup process (establishment process) is performed between the communication device 102 and the communication device 103, and three wireless links (links 1 to 3) are established. The communication device 102 (communication device 103) uses an active wireless link out of the multiple established wireless links to collect (notify) power-saving information related to the power-saving operations corresponding to each of the multiple links in the communication device 103, as exemplified below.

[0091] The communication device 103 may be configured to notify the power saving information as follows, in addition to notifying the power saving information by a response message to a request message from the communication device 102. For example, the communication device 103 may notify the power saving information for each STA (for each wireless link) at the end of frame exchange for data communication or periodically while frame exchange for data communication is being performed. Furthermore, in response to updating of the power saving information corresponding to each STA, the communication device 103 may notify the communication device 102 of the updated power saving information using the corresponding established wireless link.

[0092] 11, the communication device 103 notifies the communication device 102, using link 3, of a notification 1103 including power saving information corresponding to link 3 (STA3) before link 3 transitions to an invalid state (STA3 transitions to a doze state). Also, the communication device 103 notifies the communication device 102, using link 1, of a notification 1101 including power saving information corresponding to link 1 (STA1) before STA1 transitions to a doze state (PS-Doze) in PS mode, while link 1 remains valid. Furthermore, the communication device 103 periodically transmits to the communication device 102 a notification 1102 including power saving information corresponding to link 2 while exchanging frames for data communication using link 2.

[0093] In this way, the communication device 103 of this embodiment autonomously notifies the communication device 102 of the power saving information corresponding to each wireless link under a predetermined condition. This enables the communication device 102 to more efficiently collect power saving information related to the power saving operation of the opposing device (communication device 103).

[0094] [Other embodiments] 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.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0095] 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]

[0096] 101: Network, 102: Communication device (AP MLD), 103: Communication device (Non-AP MLD), 202: Control unit

Claims

1. A communication device that performs multi-link communication using multiple links conforming to the IEEE 802.11 series of standards, a receiving means for receiving a first frame transmitted by another communication device having a first STA (Station) and a second STA that establish the plurality of links, using the first STA; The first frame received by the receiving means does not include information on the power management mode of the first STA, but includes information on the power management mode of the second STA. A communication device comprising:

2. The Power Management Mode information is information indicating whether the state of the STA is an active state or a power saving state.

2. The communication device according to claim 1.

3. The communication device comprises: It has a first AP (Access Point) and a second AP.

3. The communication device according to claim 1 or 2.

4. The communication device further comprises: establishing a first link between the first AP and the first STA of the other communication device; and an establishment means for establishing a second link between the second AP and the second STA of the other communication device.

4. The communication device according to claim 3.

5. The first link and the second link established by the establishing means are maintained in parallel.

5. The communication device according to claim 4.

6. The establishing means establishing the first link using one frequency band of a 2.4 GHz band, a 5 GHz band, or a 6 GHz band; Establishing the second link using one frequency band of the 2.4 GHz band, the 5 GHz band, and the 6 GHz band.

6. The communication device according to claim 4 or 5.

7. The receiving means periodically receiving the first frame from the other communication device; 7. The communication device according to claim 1, wherein the first and second communication terminals are connected to each other.

8. The receiving means: The first frame is received before the state of the first STA and / or the second STA of the other communication device transitions.

7. The communication device according to claim 1, wherein the first and second communication terminals are connected to each other.

9. The state transition of the first STA and / or the second STA possessed by the other communication device means that the state of the first STA and / or the second STA transitions from an awake state to a doze state, or the state of the first STA and / or the second STA transitions from a doze state to an awake state.

9. A communication device according to claim 1, wherein the communication device is a communication device.

10. The communication device further comprises: a switching means for switching the state of each of the first link and the second link between an enabled state in which frame exchange is possible and an disabled state in which frame exchange is impossible; 7. The communication device according to claim 4, wherein the first and second communication terminals are connected to each other.

11. The communication device receives the first frame using the link that has been enabled by the switching means.

11. The communication device according to claim 10.

12. The second link is a link that has been enabled by the switching means.

12. The communication device according to claim 10 or 11.

13. The communication device is an access point multi-link device (AP MLD).

13. A communication device according to any one of claims 1 to 12.

14. A communication device that performs multi-link communication using multiple links conforming to the IEEE 802.11 series of standards, a first STA and a second STA that establish the plurality of links; a transmitting means for transmitting a first frame to another communication device using the first STA; The first frame transmitted by the transmitting means does not include information on the power management mode of the first STA, but includes information on the power management mode of the second STA. A communication device comprising:

15. The information on the Power Management Mode is information indicating whether the state of the STA is an active state or a power saving state.

15. The communication device according to claim 14.

16. The other communication device: having a first AP and a second AP 16. A communication device according to claim 14 or 15.

17. The communication device further comprises: establishing a first link between the first STA and the first AP; and establishing means for establishing a second link between the second STA and the second AP.

17. The communication device according to claim 16.

18. The communication device maintains the first link and the second link established by the establishing means in parallel.

18. The communication device according to claim 17.

19. The establishing means establishing the first link using one frequency band of a 2.4 GHz band, a 5 GHz band, or a 6 GHz band; Establishing the second link using one frequency band of the 2.4 GHz band, the 5 GHz band, and the 6 GHz band.

19. A communication device according to claim 17 or 18.

20. The transmitting means periodically transmits the first frame to the other communication device.

20. A communication device according to any one of claims 14 to 19.

21. The transmitting means transmits the first frame before a state transition occurs in the first STA and / or the second STA possessed by the communication device.

20. A communication device according to any one of claims 14 to 19.

22. The state transition of the first STA and / or the second STA possessed by the communication device means that the state of the first STA and / or the second STA transitions from an awake state to a doze state, or the state of the first STA and / or the second STA transitions from a doze state to an awake state.

22. The communication device according to claim 21 .

23. The communication device further comprises: a switching means for switching the state of each of the first link and the second link between an enabled state in which frame exchange is possible and an disabled state in which frame exchange is impossible; 20. A communication device according to any one of claims 17 to 19.

24. The communication device transmits the first frame using the link that has been enabled by the switching means.

24. The communication device of claim 23.

25. The second link is a link that is enabled by the switching means.

25. A communication device according to claim 23 or 24.

26. The communication device is a non-access point multi-link device (Non-AP MLD).

26. A communication device according to any one of claims 14 to 25.

27. ​​A control method for a communication device that performs multi-link communication using multiple links conforming to the IEEE 802.11 series of standards, comprising: a receiving step of receiving a first frame transmitted by another communication device having a first STA (Station) and a second STA that establish the plurality of links, using the first STA; The first frame received in the receiving step does not include information on the power management mode of the first STA, but includes information on the power management mode of the second STA. A method for controlling a communication device.

28. A control method for a communication device that performs multi-link communication using multiple links conforming to the IEEE 802.11 series of standards, comprising: a first STA and a second STA that establish the plurality of links; a transmitting step of transmitting a first frame to another communication device using the first STA; The first frame transmitted in the transmitting step does not include information on a power management mode of the first STA, but includes information on a power management mode of the second STA. A method for controlling a communication device.

29. A program for causing a computer to execute each step of the method for controlling a communication device according to claim 27 or 28.

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