Communication device, communication method, and program

Abstract

To provide a mechanism for setting up multi-link communication using Association Request / Association Response.SOLUTION: A communication device is for performing wireless communication in accordance with the IEEE 802.11 series standards over a plurality of wireless communication links with different frequencies in use. When another communication device receives an Association Request frame containing information indicating a plurality of links on which other communication devices request establishments of wireless communication links and accepts establishments of wireless communication links for a part of the plurality of links indicated by the above-described information and rejects establishments of wireless communication links for a part of the plurality of links, the communication device sets information of a Status code common to the plurality of links, which is a Status code included in the Association Response frame to information indicating a success, and transmits the frame to the other communication device.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a communication device that performs wireless communication. [Background technology]

[0002] With the recent increase in the amount of data being communicated, development of communication technologies such as wireless local area networks (LANs) is progressing. The IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series is known as a major communication standard for wireless LANs. The IEEE 802.11 standard series includes standards such as IEEE 802.11a / b / g / n / ac / ax. For example, the latest standard, IEEE 802.11ax, uses orthogonal frequency division multiple access (OFDMA) to standardize technology that not only achieves a high peak throughput of up to 9.6 gigabits per second (Gbps) but also improves communication speeds under congested conditions (see Patent Document 1). OFDMA stands for Orthogonal Frequency Division Multiple Access.

[0003] A task group called IEEE802.11be was established as a successor standard aiming to further improve throughput, frequency utilization efficiency, and communication latency.

[0004] IEEE802.11be is considering multi-link communication, in which one AP establishes multiple links with one STA (Station) using frequency bands such as 2.4GHz, 5GHz, and 6GHz, enabling simultaneous communication. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-50133 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the IEEE 802.11 standard does not specify the details of the setup procedure for multi-link communication. In particular, it does not specify what content of the association response a communication device should send when it cannot agree to establish some of the multiple links requested using an association request. Furthermore, it does not specify what sequence a communication device that receives an association response should follow to establish multi-link communication with the other device.

[0007] Therefore, an object of the present invention is to provide a mechanism for setting up multi-link communication using an Association Request / Association Response. [Means for solving the problem]

[0008] In order to achieve the above object, the communication device of the present invention is a communication device that performs wireless communication in accordance with the IEEE802.11 series standard via multiple wireless communication links using different frequencies, and is characterized by having: a receiving means for receiving an Association Request frame that includes information indicating multiple links for which another communication device requests the establishment of a wireless communication link; and a transmitting means for, when the establishment of a wireless communication link is accepted for some of the multiple links indicated in the information and rejected for some of the links, setting information of a Status code included in an Association Response frame that is common to the multiple links to information indicating success, and transmitting the Association Response frame to the other communication device.

[0009] In addition, in order to achieve the above object, the communication device of the present invention is a communication device that performs wireless communication in accordance with the IEEE802.11 series standard via multiple wireless communication links using different frequencies, and is characterized by having: a receiving means for receiving an Association Request frame that includes information indicating multiple links for which another communication device requests the establishment of a wireless communication link; and a transmitting means for, when the establishment of a wireless communication link is accepted for some of the multiple links indicated in the information and rejected for some of the links, setting information of a Status code included in an Association Response frame that is common to the multiple links to information indicating failure, and transmitting the Association Response frame to the other communication device.

[0010] Furthermore, in order to achieve the above object, a communication device of the present invention is a communication device that performs wireless communication in accordance with the IEEE 802.11 series standard via multiple wireless communication links using different frequencies, and is characterized by having: first transmission means for transmitting an Association Request frame including information indicating multiple links for which establishment of a wireless communication link is requested; receiving means for receiving, as a response to the Association Request frame, an Association Response frame in which information on a Status code included in the Association Response frame that is common to the multiple links is set to information indicating failure; generation means for generating, in response to reception of the Association Request frame by the receiving means, an Association Request frame that specifies the link for which establishment of a wireless communication link has been agreed in the Association Request frame as the link for which establishment of a wireless communication link is requested; and second transmission means for transmitting the Association Request frame generated by the generation means. [Effects of the Invention]

[0011] According to the present invention, multi-link communication can be set up using an Association Request / Association Response. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating a network configuration according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating a hardware configuration of a communication device according to the present embodiment. [Figure 3] FIG. 2 is a diagram illustrating a functional configuration of a communication device according to the present embodiment. [Figure 4] FIG. 10 is a sequence diagram of a first example of a setup process for multi-link communication in this embodiment. [Figure 5] FIG. 10 is a sequence diagram of a second example of a setup process for multi-link communication in this embodiment. [Figure 6] FIG. 10 is a sequence diagram of a setup process of a third example of Multi-link communication in this embodiment. [Figure 7] FIG. 10 is a sequence diagram of a setup process of a fourth example of Multi-link communication in this embodiment. [Figure 8] FIG. 10 is a sequence diagram of a setup process of a fifth example of Multi-link communication in this embodiment. [Figure 9] 10 is a flowchart showing a process executed by an AP MLD in the present embodiment. [Figure 10] 10 is a flowchart showing a process executed by non-AP MLD in the present embodiment. [Figure 11] 10 is a flowchart showing a process executed by an AP MLD in the present embodiment. [Figure 12] 10 is a flowchart showing a process executed by non-AP MLD in the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the configurations shown in the following embodiments are merely examples, and the present invention is not limited to the illustrated configurations.

[0014] (Configuration of wireless communication system) 1 shows the configuration of a network searched by a communication device 101 (hereinafter referred to as Non-AP MLD 101) according to this embodiment. A communication device 102 (hereinafter referred to as AP MLD 102) is an access point (AP) that serves to construct a wireless network 100. The AP MLD 102 can communicate with the Non-AP MLD 101. This embodiment is applied to the Non-AP MLD 101 and the AP MLD 102.

[0015] Each of the non-AP MLD 101 and the AP MLD 102 can perform wireless communication compliant with the IEEE 802.11be (EHT) standard. IEEE stands for Institute of Electrical and Electronics Engineers. The non-AP MLD 101 and the AP MLD 102 can communicate in the 2.4 Hz, 5 GHz, and 6 GHz frequency bands. The frequency bands used by each communication device are not limited to these, and different frequency bands, such as the 60 GHz band, may be used. The non-AP MLD 101 and the AP MLD 102 can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz. The bandwidths used by each communication device are not limited to these, and different bandwidths, such as 240 MHz and 4 MHz, may be used.

[0016] The Non-AP MLD 101 and AP MLD 102 perform OFDMA communication compliant with the IEEE802.11be standard, enabling multi-user (MU) communication by multiplexing signals from multiple users. OFDMA stands for Orthogonal Frequency Division Multiple Access. In OFDMA communication, portions of the divided frequency band (RU, Resource Unit) are assigned to each STA without overlapping, and the carrier waves of each STA are orthogonal. This allows the AP to communicate with multiple STAs in parallel within a specified bandwidth.

[0017] Although the non-AP MLD 101 and the AP MLD 102 are described as being compatible with the IEEE 802.11be standard, they may also be compatible with legacy standards that predate the IEEE 802.11be standard. Specifically, the non-AP MLD 101 and the AP MLD 102 may be compatible with at least one of the IEEE 802.11a / b / g / n / ac / ax standards. In addition to the IEEE 802.11 series standards, they may also be compatible with other communication standards such as Bluetooth (registered trademark), NFC, UWB, ZigBee, and MBOA. UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, and the like. They may also be compatible with wired communication standards such as wired LAN. Specific examples of the AP MLD 102 include, but are not limited to, a wireless LAN router and a personal computer (PC). The AP MLD 102 may also be an information processing device such as a wireless chip capable of performing wireless communication in accordance with the IEEE802.11be standard. Specific examples of the Non-AP MLD 101 include, but are not limited to, a camera, a tablet, a smartphone, a PC, a mobile phone, a video camera, a headset, etc. The Non-AP MLD 101 may also be an information processing device such as a wireless chip capable of performing wireless communication in accordance with the IEEE802.11be standard.

[0018] Each communication device is capable of communicating using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz.

[0019] The non-AP MLD 101 and the AP MLD 102 also perform multi-link communication, establishing links and communicating via multiple frequency channels. The IEEE 802.11 series of standards defines the bandwidth of each frequency channel as 20 MHz. Here, the frequency channel refers to a frequency channel defined in the IEEE 802.11 series of standards, and the IEEE 802.11 series of standards defines multiple frequency channels for each of the 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz frequency bands. Note that by bonding adjacent frequency channels, a bandwidth of 40 MHz or more may be used in one frequency channel. For example, the AP MLD 102 is capable of establishing a link and communicating with the non-AP MLD 101 via a first frequency channel in the 2.4 GHz band. In parallel with this, the non-AP MLD 101 is capable of establishing a link and communicating with the AP MLD 102 via a second frequency channel in the 5 GHz band. In this case, the non-AP MLD 101 performs multi-link communication, maintaining a second link via the second frequency channel in parallel with the link via the first frequency channel. In this way, the AP MLD 102 can improve the throughput of communication with the non-AP MLD 101 by establishing links with the non-AP MLD 101 via multiple frequency channels.

[0020] In multi-link communication, multiple links using different frequency bands may be established between communication devices. For example, the non-AP MLD 101 may be able to establish links in the 2.4 GHz, 5 GHz, and 6 GHz bands. Alternatively, links may be established via multiple different channels within the same frequency band. For example, a link on channel 6 in the 2.4 GHz band may be established as the first link, and a link on channel 1 in the 2.4 GHz band may be established as the second link. Links using the same frequency band and links using different frequency bands may be mixed. For example, the non-AP MLD 101 may be able to establish a first link on channel 6 in the 2.4 GHz band, as well as a link on channel 1 in the 2.4 GHz band and a link on channel 149 in the 5 GHz band. By establishing multiple connections using different frequencies between the non-AP MLD 101 and the AP, even if one band is congested, a connection with the non-AP MLD 101 can be established in another band. This prevents degradation of throughput and communication delays in communication with the non-AP MLD 101.

[0021] Although the wireless network in Figure 1 has one AP MLD and one non-AP MLD, the number and arrangement of AP MLDs and non-AP MLDs are not limited to this. For example, one non-AP MLD may be added to the wireless network in Figure 1. In this case, the frequency band, number of links, and frequency width of each established link are not important. In the example in Figure 1, three links 104, 105, and 106 are established, but the number of links established in multi-link communication is not limited to this.

[0022] When performing multi-link communication, the AP MLD 102 and the non-AP MLD 101 transmit and receive data to and from other devices via multiple links. The AP MLD 102 and the non-AP MLD 101 may also be capable of MIMO (Multiple-Input and Multiple-Output) communication. In this case, the AP MLD 102 and the non-AP MLD 101 each have multiple antennas, and each transmits different signals from the respective antennas using the same frequency channel. The receiving side simultaneously receives all signals arriving from multiple streams using multiple antennas, and separates and decodes the signals from each stream. By performing MIMO communication in this way, the AP MLD 102 and the non-AP MLD 101 can communicate more data in the same amount of time than when not performing MIMO communication. When performing multi-link communication, the AP MLD 102 and the non-AP MLD 101 may also perform MIMO communication on some of the links.

[0023] (Configuration of AP MLD and Non-AP MLD) 2 shows an example of the hardware configuration of the non-AP MLD 101 in this embodiment. The non-AP MLD 101 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 there may be multiple antennas.

[0024] The storage unit 201 is configured with one or more memories such as ROM and RAM, and stores various information such as computer programs for performing various operations described below and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. In addition to memories such as ROM and RAM, the storage unit 201 may also use storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs. Furthermore, the storage unit 201 may include multiple memories.

[0025] The control unit 202 is configured with one or more processors such as a CPU or MPU, and controls the entire Non-AP MLD 101 by executing a computer program stored in the storage unit 201. Note that the control unit 202 may also control the entire Non-AP MLD 101 in cooperation with the computer program stored in the storage unit 201 and an OS (Operating System). The control unit 202 also generates data and signals (wireless frames) to be transmitted in communications with other communication devices. Note that CPU is an abbreviation for Central Processing Unit, and MPU is an abbreviation for Micro Processing Unit. Also, the control unit 202 may be provided with multiple processors such as multi-core processors, and the entire Non-AP MLD 101 may be controlled by the multiple processors.

[0026] Furthermore, the control unit 202 controls the function unit 203 to perform predetermined processes such as wireless communication, image capture, printing, projection, etc. The function unit 203 is hardware that enables the non-AP MLD 101 to perform predetermined processes.

[0027] 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 a display on a monitor screen, an audio output from a speaker, a vibration output, or the like. Note that both the input unit 204 and the output unit 205 may be implemented in a single module, such as a touch panel. Furthermore, the input unit 204 and the output unit 205 may be integrated with the Non-AP MLD 101, or may be separate units.

[0028] The communication unit 206 controls wireless communication in accordance with the IEEE 802.11be standard. The communication unit 206 may also control wireless communication in accordance with other IEEE 802.11 series standards in addition to the IEEE 802.11be standard, or control wired communication such as a wired LAN. While the present embodiment will be described using the IEEE 802.11be standard as an example, this embodiment can also be applied to IEEE 802.11 series standards formulated later as long as they enable multi-link communication. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202.

[0029] If the non-AP MLD 101 supports the NFC standard, Bluetooth standard, or the like in addition to the IEEE802.11be standard, it may control wireless communications in accordance with these communication standards. Furthermore, if the non-AP MLD 101 can perform wireless communications in accordance with multiple communication standards, it may be configured to have separate communication units and antennas compatible with each communication standard. The non-AP MLD 101 communicates data such as image data, document data, and video data with the non-AP MLD 101 via the communication unit 206. The antenna 207 may be configured as a separate unit from the communication unit 206, or may be configured together with the communication unit 206 as a single module.

[0030] Antenna 207 is an antenna capable of communication in the 2.4 GHz band, 5 GHz band, and 6 GHz band. In this embodiment, non-AP MLD 101 has one antenna, but it may have three antennas. Alternatively, it may have a different antenna for each frequency band. Furthermore, if non-AP MLD 101 has multiple antennas, it may have a communication unit 206 corresponding to each antenna.

[0031] The AP MLD 102 has the same hardware configuration as the non-AP MLD 101 .

[0032] FIG. 3 is a functional block diagram of the AP MLD 102 and the non-AP MLD 101. As shown in FIG.

[0033] Reference numerals 301 to 306 denote functions of the AP MLD 102, which are implemented by software or hardware. The Multi-link control unit 301 controls the Multi-link established with the Non-AP MLD 101 and executes Multi-link communication. The Assoc Req processing unit 302 receives an Association Request frame from the Non-AP MLD 101, analyzes its contents, and processes it. The Assoc Rsp generation unit 303 generates an Association Response frame, which is a response message to the Association Request frame, and transmits it to the Non-AP MLD 101. The Link switching unit 304 performs processing to appropriately switch the link established with the Non-AP MLD 101. The 4WHS processing unit 305 shares an encryption key with the Non-AP MLD 101 by executing 4-way handshake processing defined in the IEEE 802.11 standard. The frame transmission / reception unit 306 transmits and receives wireless frames to and from a partner device of wireless communication (e.g., the Non-AP MLD 101).

[0034] Reference numerals 401 to 406 denote functions of the Non-AP MLD 101, which are implemented by software or hardware. The Multi-link control unit 401 controls the Multi-link established with the AP MLD 102 and executes Multi-link communication. The Assoc Req generation unit 402 generates an Association Request frame to be transmitted to the AP MLD 102. The Assoc Rsp processing unit 403 receives an Association Response frame transmitted from the AP MLD 102, analyzes its contents, and processes them. The Link switching unit 404 performs processing to appropriately switch the link established with the AP MLD 101. The 4WHS processing unit 405 shares an encryption key with the AP MLD 101 by executing 4-way handshake processing defined in the IEEE 802.11 standard. The frame transmission / reception unit 406 transmits and receives wireless frames to and from a partner device of wireless communication (e.g., the AP MLD 102).

[0035] Next, the sequence of the setup process for Multi-link communication in this embodiment will be described with reference to Figures 4 to 8. Figures 4 to 8 show different setup processes, but all or part of these may be combined as appropriate and executed. Alternatively, these processes may be selectively executed depending on the user's operation or the state of the communication device.

[0036] First, a prerequisite process for the overall setup process of multi-link communication in this embodiment will be described.

[0037] The Non-AP MLD 101 specifies the link to be set up in the Association Request.

[0038] The Non-AP MLD 101 stores one or more Per-STA Profile subelements corresponding to the link to be set up in the Association Request. Specifically, it stores them in the Link Info field of the Basic variant Multi-link element of the Association Request frame. At this time, the requested link is specified by the Link ID.

[0039] On the other hand, the AP MLD 102 specifies the link for which it has accepted the setup in the Association Response. If the AP MLD 102 does not accept a link that was requested by the non-AP MLD 101 but not used to send the Association Request, it performs the following: It stores the Per-STA Profile subelement corresponding to that link in the Association Response. Specifically, it includes this in the Link Info field of the Basic variant Multi-link element of the Association Request frame. It also includes the reason for the failure in the Status Code subfield of the Per-STA Profile subelement of the Basic variant Multi-link element.

[0040] The AP MLD 102 stores one or more Per-STA Profile subelements containing complete information about the APs of the accepted and requested links in the Association Response. Specifically, the subelements are included in the Link Info field of the Basic variant Multi-link element of the Association Response frame. At this time, the accepted links are notified by their Link IDs.

[0041] FIG. 4 shows a first example of a setup process for multi-link communication in this embodiment. In FIG. 4, each of the non-AP MLD 101 and AP MLD 102 is configured to be able to establish three wireless links, and wireless links are actually established using all or some of these links depending on the device status at the time. The non-AP MLD 101 and AP MLD 102 each include stations 1 to 3 (STA1, STA2, STA3) and access points 1 to 3 (AP1, AP2, AP3). Wireless links are established by connections between stations 1 to 3 (STA1, STA2, STA3) included in the non-AP MLD 101 and AP MLD 102 and access points 1 to 3 (AP1, AP2, AP3). In the following explanation, Link 1 is established by the connection between STA1 and AP1, Link 2 is established by the connection between STA2 and AP2, and Link 3 is established by the connection between STA3 and AP3. This also applies to the following explanations of FIGS. 5 to 8. In this embodiment, each of the non-AP MLD 101 and the AP MLD 102 is configured to be able to establish three wireless links, that is, to include STAs 1 to 3 and APs 1 to 3, but the number of wireless links that can be established is not limited to this.

[0042] First, the Non-AP MLD Supplicant of the non-AP MLD 101 stores the Per-STA Profile subelements of Links 1, 2, and 3 in an Association Request frame. Specifically, it stores them in the Link Info field of the Basic variant Multi-link element of the Association Request frame. Furthermore, it generates an Association Request frame storing the above information in the Link Info field (S401) and transmits the Association Request frame generated in S401 to AP1 (S402). AP1 receives the Association Request frame transmitted in S402 and passes it to the AP MLD Authenticator of the AP MLD 102 (S403). The AP MLD Authenticator sets the Status codes of Links 1 and 2 to "success" in the Per-STA Profile subelement of the Basic variant Multi-link element. Furthermore, it generates an Association Response frame with the Status code of the Association Response set to "success" (S404). Here, the status code of the association response is a status code common to multiple links. AP1 transmits the association response frame generated in S404 to STA1 (S405). STA1 receives the association response frame transmitted in S405 and passes it to the non-AP MLD supplicant of non-AP MLD 101 (S406).

[0043] After that, the non-AP MLD 101 and AP MLD 102 perform steps S407 to S419 to execute a 4-way handshake. In this 4-way handshake, a GTK (Group Temporal Key) is generated for each of Link1 and Link2, for which link establishment has been approved by the AP MLD 102. A GTK is not generated for Link3, for which link establishment has not been approved by the AP MLD 102. The AP MLD Authenticator installs the GTK generated by the 4-way handshake (S417). The non-AP MLD Supplicant installs the GTK generated by the 4-way handshake (S416). As explained above, in the first example, if the AP MLD approves some of the links for which setup has been requested, it sets the STATUS CODE of the Association Response to SUCCESS. Then, the AP MLD transmits only the GTKs for the approved links in the 4-way handshake.

[0044] 5 shows a second example of the setup process for multi-link communication in this embodiment. In this second example, when the AP MLD accepts some of the links requested for setup, it sets the STATUS CODE of the Association Response to SUCCESS. When the AP MLD accepts a single link (the link that is transmitting and receiving associations), it sends an Association Response that does not include a Basic variant Multi-link element. A Non-AP MLD that receives an Association Response that does not include a Basic variant Multi-link element performs a normal 4-way handshake. Differences from the first example described above will be described in detail below.

[0045] S501 to S503 are the same as S401 to S403 in Fig. 4. The AP MLD Authenticator generates an Association Response frame that does not include a Basic variant Multi-link element and has a Status code of success (S504). AP1 transmits the Association Response frame generated in S504 to STA1 (S505). STA1 receives the Association Response frame transmitted in S505 and passes it to the Non-AP MLD Supplicant of the non-AP MLD 101 (S506).

[0046] After that, the non-AP MLD 101 and AP MLD 102 perform the processes of S507 to S512 and execute a 4-way handshake. This 4-way handshake is executed on Link 1, the link over which the Association Response frame was sent. The AP MLD Authenticator installs the GTK generated by the 4-way handshake (S511). The non-AP MLD Supplicant installs the GTK generated by the 4-way handshake (S510). The GTK installed in S510 and S511 is the GTK used for communication on Link 1.

[0047] 6 shows a third example of the setup process for multi-link communication in this embodiment. In this third example, when AP MLD accepts some of the links requested for setup, it sets the STATUS CODE of the Association Response to SUCCESS. If the link for which the Association Response is returned is not the accepted link, it switches to the accepted link and performs a 4-way handshake. The following describes in detail the differences from the first example described above.

[0048] S601 to S603 are the same as S401 to S403 in Fig. 4. The AP MLD Authenticator sets the Status codes for Link2 and Link3 to success in the Per-STA Profile subelement of the Basic variant Multi-link element. Here, the Status code success means that the requests for Link2 and Link3 were successful. Furthermore, an Association Response frame is generated with the Status code of the Association Response set to success (S604). AP1 transmits the Association Response frame generated in S604 to STA1 (S605). STA1 receives the Association Response frame transmitted in S605 and passes it to the Non-AP MLD Supplicant of the non-AP MLD 101 (S606).

[0049] Thereafter, the non-AP MLD 101 and AP MLD 102 perform the processes of S607 to S620 to execute a 4-way handshake. The 4-way handshake here is executed using Link2 or Link3, for which link establishment has been approved, rather than Link1, for which the Association Response frame was transmitted. In the example of Fig. 6, the 4-way handshake is executed using Link2. In this 4-way handshake process, a GTK (Group Temporal Key) is generated for each of Link2 and Link3, for which link establishment has been approved by the AP MLD 102. A GTK is not generated for Link1, for which link establishment has not been approved by the AP MLD 102. The AP MLD Authenticator installs the GTK generated by the 4-way handshake (S617). The Non-AP MLD Supplicant installs the GTK generated by the 4-way handshake (S616).

[0050] FIG. 7 shows a fourth example of the setup process for multi-link communication in this embodiment. In this fourth example, when the AP MLD rejects some of the links requested for setup, it sets the STATUS CODE of the Association Response to FAIL. Note that there may be multiple ways to indicate FAIL. For example, multiple STATUS_CODEs other than SUCCESS, such as REFUSED_BAD_SUPPORTED_CHANNELS and STATUS_INVALID_PMK, may be defined to indicate a detailed reason for FAIL. Here, REFUSED_BAD_SUPPORTED_CHANNELS is a STATUS CODE indicating that the channel is not supported, and STATUS_INVALID_PMK is a STATUS CODE indicating that the PMKID is invalid. When the Non-AP MLD receives an Association Response with a STATUS CODE of FAIL, and the Association Response contains some accepted Links, it resends an Association Request containing only the accepted Links. Below, the differences from the first example described above will be explained in detail.

[0051] S701 to S703 are the same as S401 to S403 in FIG.

[0052] The AP MLD Authenticator sets the Status code for Link1 and Link2 to success in the Per-STA Profile subelement of the Basic variant Multi-link element. Furthermore, in S704, AP1 generates an Association Response frame in which the Status code of the Association Response is set to fail. AP1 transmits the Association Response frame generated in S704 to STA1 (S705). STA1 receives the Association Response frame transmitted in S705 and passes it to the Non-AP MLD Supplicant of the non-AP MLD 101 (S706).

[0053] The Non-AP MLD Supplicant then stores the Per-STA Profile subelement for Links 1 and 2 accepted by the AP MLD 102 in an Association Request frame. Here, this subelement is stored in the Link Info field of the Basic variant Multi-link element of the Association Request frame. An Association Request frame is generated that stores the Link Info field of the Basic variant Multi-link element (S707). In other words, the Non-AP MLD Supplicant regenerates an Association Request frame that does not include the Per-STA Profile subelement for the link whose link establishment was rejected by the AP MLD 102. STA1 transmits the Association Request frame generated in S707 to AP1 (S708). AP1 receives the Association Request frame transmitted in S708 and passes it to the AP MLD Authenticator of the AP MLD 102 (S709).

[0054] Upon receiving this, the AP MLD Authenticator sets the Status codes for Link1 and Link2 to success in the Per-STA Profile subelement of the Basic variant Multi-link element. An Association Response frame is generated in which the Status code of the Association Response is set to success (S710). AP1 transmits the Association Response frame generated in S710 to STA1 (S711). STA1 receives the Association Response frame transmitted in S711 and passes it to the Non-AP MLD Supplicant of the non-AP MLD 101 (S712).

[0055] After that, the non-AP MLD 101 and AP MLD 102 perform the processes from S713 onwards and execute a 4-way handshake. In this 4-way handshake process, a GTK (Group Temporal Key) is generated for each of Link1 and Link2, for which link establishment has been approved by the AP MLD 102. A GTK is not generated for Link3, for which link establishment has not been approved by the AP MLD 102. The AP MLD Authenticator and Non-AP MLD Supplicant each install the GTK generated by the 4-way handshake.

[0056] 8 shows a fifth example of the setup process for multi-link communication in this embodiment. In the fifth example, when AP MLD rejects some of the links requested for setup, it sets the STATUS CODE of the Association Response to FAIL. If the link for which the Association Response is returned is not the accepted link, it switches to the accepted link and sends an Association Request. The following describes in detail the differences from the first example described above.

[0057] S801 to S803 are the same as S401 to S403 in Figure 4. The AP MLD Authenticator sets the Status codes for Link2 and Link3 to success in the Per-STA Profile subelement of the Basic variant Multi-link element. It then generates an Association Response frame in which the Status code of the Association Response is set to fail (S804). AP1 transmits the Association Response frame generated in S804 to STA1 (S805). STA1 receives the Association Response frame transmitted in S805 and passes it to the Non-AP MLD Supplicant of the non-AP MLD 101 (S806).

[0058] The Non-AP MLD Supplicant then stores the Per-STA Profile subelement for Links 2 and 3, which was approved by the AP MLD 102, in the Association Request frame. The Per-STA Profile subelement for Links 2 and 3, which was approved by the AP MLD 102, is stored in the Link Info field of the Basic variant Multi-link element. An Association Request frame storing the above information is then generated (S807). That is, the Non-AP MLD Supplicant regenerates an Association Request frame that does not include the Per-STA Profile subelement for the link for which link establishment was rejected by the AP MLD 102. STA2 then transmits the Association Request frame generated in S807 to AP2 (S808). In the fifth example of FIG. 8, the regenerated Association Request frame is transmitted using the link for which multi-link setup was approved, rather than the link for which multi-link setup was rejected. In this example, the Association Request frame is transmitted using Link 2, not Link 1. AP2 receives the Association Request frame sent in S808 and passes it to the AP MLD Authenticator of the AP MLD 102 (S809).

[0059] Upon receiving this, the AP MLD Authenticator sets the Status codes for Link2 and Link3 of the Per-STA Profile subelement of the Basic variant Multi-link element to success. It then generates an Association Response frame in which the Status code of the Association Response is set to success (S810). AP2 transmits the Association Response frame generated in S810 to STA2 (S811). STA2 receives the Association Response frame transmitted in S811 and passes it to the Non-AP MLD Supplicant of the non-AP MLD 101 (S812).

[0060] After that, the non-AP MLD 101 and AP MLD 102 perform the processes from S813 onwards and execute a 4-way handshake. In this 4-way handshake process, a GTK (Group Temporal Key) is generated for each of Link2 and Link3, for which link establishment has been approved by the AP MLD 102. A GTK is not generated for Link1, for which link establishment has not been approved by the AP MLD 102. The AP MLD Authenticator and Non-AP MLD Supplicant each install the GTK generated by the 4-way handshake.

[0061] As described above, in any of the first to fifth examples, multi-link communication can be set up using an Association Request / Association Response.

[0062] Next, the processing executed by the non-AP MLD 101 and the AP MLD 102 in the first to fifth examples described above will be described using the flowcharts of Figures 9 to 12. Figure 9 is a flowchart showing the processing by the AP MLD 102 corresponding to the first to third examples described above. Figure 10 is a flowchart showing the processing by the non-AP MLD 101 corresponding to the first to third examples described above. Figure 11 is a flowchart showing the processing by the AP MLD 102 corresponding to the fourth and fifth examples described above. Figure 12 is a flowchart showing the processing by the non-AP MLD 101 corresponding to the fourth and fifth examples described above. The processing of each step shown in these flowcharts is realized by the processor of the control unit 202 or communication unit 206 provided in each of the non-AP MLD 101 and AP MLD 102 executing a program stored in the storage unit 201 or the like. Note that some of the processing in the flowcharts may be executed using dedicated hardware.

[0063] 9 shows the multi-link setup process executed by the AP MLD 102. First, the AP MLD 102 executes authentication processing with the non-AP MLD. After the authentication processing is successful, the AP MLD 102 determines whether it has received an Association Request from the non-AP MLD (S901). If it is determined that an Association Request has been received, it determines whether it can accept all or some of the links requested for multi-link setup by the Association Request (S902). If it is determined that all or some of the links can be accepted, it executes processing in S903. If none of the requested links are acceptable, that is, if there is not a single link that can be accepted, it executes processing in S910. In S903, the AP MLD 102 generates an Association Response frame with the Status code of the Association Response set to success. Then, the AP MLD 102 determines whether only one link has been accepted (S904). If the number of accepted links is one, the AP MLD 102 transmits the Association Response frame generated in S903 to the non-AP MLD (S906). On the other hand, if the number of accepted links is more than one, the AP MLD 102 generates a Multi-link element based on the information on the accepted links and the rejected links and stores it in the Association Response frame (S905). Then, the AP MLD 102 transmits the Association Response frame generated in S905 to the non-AP MLD (S906).

[0064] Thereafter, the AP MLD 102 determines whether or not the link on which the Association Request was received in S901 was accepted (S907). If the link on which the Association Request was received was not accepted, the AP MLD 102 switches the link to be used when executing a subsequent 4-way handshake to one of the accepted links (S908). Then, the AP MLD 102 executes a 4-way handshake with the non-AP MLD using the link switched in S908, and generates a GTK (S909). If it is determined in S907 that the received link was accepted, the AP MLD 102 executes a 4-way handshake using the link on which the Association Request / Association Response was sent and received, and generates a GTK (S909).

[0065] If all of the requested links in S902 are not acceptable, the AP MLD 102 generates an Association Response frame with the Status code set to fail (S910).The AP MLD 102 then generates a Multi-link element based on the information about the rejected links and stores it in the Association Response frame (S911).The AP MLD 102 transmits the Association Response frame generated in S911 to the non-AP MLD (S912).

[0066] 10 shows the multi-link setup process executed in the non-AP MLD 101. First, the non-AP MLD 101 executes authentication processing with the AP MLD (S1001). If the authentication processing is successful, the non-AP MLD 101 determines whether or not to execute multi-link communication with the AP MLD (S1002). If multi-link communication is to be executed, a multi-link element containing information about the link for which multi-link communication is requested is generated and stored in an association request frame (S1003). The non-AP MLD 101 transmits the generated association request frame to the AP MLD (S1004). If it is determined in S1002 that multi-link communication is not to be performed, the non-AP MLD 101 transmits an Association Request frame to the AP MLD without executing S1003.

[0067] When an Association Response frame is received in response to the Association Request frame sent in S1005, it is determined in S1006 whether the status code in the frame is success. If the result of the determination in S1006 is not success, the association process is considered to have failed and the process is terminated. If the result of the determination in S1006 is success, the non-AP MLD 101 determines whether the link that sent the Association Request frame has been accepted (S1007). If the result of the determination in S1007 is that the link has not been accepted, the non-AP MLD 101 switches the link that will perform the 4-way handshake with the AP MLD to an accepted link (S1008). Thereafter, the non-AP MLD 101 performs a 4-way handshake with the AP MLD and generates a GTK (S1009). If it is determined in S1007 that the link that sent the Association Request has been accepted, a GTK is generated using the link that sent and received the Association Request / Association Response (S1009). Here, a 4-way handshake is performed to generate the GTK.

[0068] 11 shows the multi-link setup process executed in the AP MLD 102. First, the AP MLD 102 executes authentication processing with the non-AP MLD (S1101). After the authentication processing is successful, the AP MLD 102 determines whether or not it has received an association request from the non-AP MLD (S1102). If it is determined that an association request has been received, the AP MLD 102 determines whether it can accept all of the links for which multi-link setup is requested by the frame (S1103). If it is determined that it can accept all of the requested links, it executes processing in S1104, and if it is not possible to accept at least some of the requested links, it executes processing in S1108.

[0069] In S1104, the AP MLD 102 generates an Association Response frame with the Status code of the Association Response set to success. The AP MLD 102 generates a Multi-link element based on the information of the accepted link and stores it in the Association Response frame (S1105). The AP MLD 102 transmits the Association Response frame generated in S1105 to the non-AP MLD (S1106). The AP MLD 102 then executes a 4-way handshake with the non-AP MLD and generates a GTK for the accepted link (S1107).

[0070] Meanwhile, in S1108, the AP MLD 102 generates an Association Response frame in which the Status code of the Association Response is set to fail.The AP MLD 102 then generates a Multi-link element based on the information on the accepted and rejected links and stores it in the Association Response frame (S1109).The AP MLD 102 transmits the Association Response frame generated in S1109 to the non-AP MLD and ends the process (S1110).

[0071] 12 shows the multi-link setup process executed in the non-AP MLD 101. First, the non-AP MLD 101 executes authentication processing with the AP MLD (S1201).

[0072] If the authentication process is successful, the non-AP MLD 101 determines whether or not to execute multi-link communication with the AP MLD (S1202). If multi-link communication is to be executed, the non-AP MLD 101 stores a multi-link element containing information about the link for which multi-link communication is requested in an association request frame (S1203). The non-AP MLD 101 transmits the generated association request frame to the AP MLD (S1204). If it is determined in S1002 that multi-link communication is not to be executed, the non-AP MLD 101 transmits the association request frame to the AP MLD without executing S1203.

[0073] When an Association Response frame is received in response to the Association Request frame sent in S1205, the non-AP MLD 101 determines whether the status code of the frame is success (S1206). If the result of the determination in S1206 is not success, the non-AP MLD 101 determines whether information about accepted links is included in the Association Response (S1207). If it is determined that there are accepted links, the non-AP MLD 101 stores a Multi-link element indicating this link information in the Association Request frame so that the accepted links are made the requested links for multi-link communication (S1208). The non-AP MLD 101 then determines whether the link for which the Association Response frame was sent has been accepted by the AP MLD (S1209). If it is determined that the link has been accepted in S1209, the non-AP MLD 101 transmits the Association Request frame generated in S1208 to the AP MLD (S1204). On the other hand, if the result of the determination in S1209 is that the association was not accepted, the link used to send the Association Request frame generated in S1208 is switched to the link accepted by the AP MLD (S1210). After that, if the result of the determination in S1206 is that the status code of the Association Response in the Association Response frame is success, a GTK is generated with the AP MLD (S1211). Here, the GTK is generated by executing a 4-way handshake between the non-AP MLD 101 and the AP MLD 102.

[0074] As described above, the non-AP MLD 101 and AP MLD 102 have the following advantages by performing any of the processes shown in Figures 9 to 12. That is, multi-link communication can be set up using an Association Request / Association Response.

[0075] (Other embodiments) It is also possible to provide a system or device with a recording medium storing software program code for implementing the above-described functions, and have the computer (CPU, MPU) of the system or device read and execute the program code stored in the recording medium. In this case, the program code itself read from the recording medium will implement the functions of the above-described embodiments, and the recording medium storing the program code will constitute the above-described device.

[0076] Examples of storage media that can be used to supply the program code include flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, ROMs, and DVDs.

[0077] In addition, the above-mentioned functions may be realized not only by the computer executing the read program code, but also by the operating system (OS) running on the computer performing some or all of the actual processing based on the instructions of the program code. OS is an abbreviation for Operating System.

[0078] Furthermore, the program code read from the storage medium is written into a memory provided on a function expansion board inserted into the computer or a function expansion unit connected to the computer. Then, based on the instructions of the program code, a CPU provided in the function expansion board or function expansion unit may perform some or all of the actual processing to realize the above-mentioned functions.

[0079] 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. [Explanation of symbols]

[0080] 201 Storage section 202 Control section 203 Functional Department 204 Input section 205 Output section 206 Communications Department

Claims

1. A wireless communication device that performs multilink communication in accordance with the IEEE 802.11 series standard, A receiving means that receives an Association Request frame containing first information identifying multiple links from another wireless communication device on a first frequency channel, If, among the multiple links identified by the first information, the establishment of a wireless communication link is accepted for the first link using the first frequency channel, but the establishment of a wireless communication link is not accepted for the second link using the second frequency channel, a transmission means transmits an Association Response frame to the other wireless communication device, which includes a first Status code and a Basic Multi-link element indicating success. It has, The Basic Multi-link element included in the Association Response frame transmitted by the transmission means is: Including the Per-STA Profile subject related to the second link mentioned above, The Per-STA Profile particular relating to the second link includes a second Status code indicating the cause of the failure. A wireless communication device characterized by the following features.

2. The wireless communication device according to claim 1, characterized in that the Per-STA Profile particular relating to the second link includes a Link ID indicating the second link.

3. The second link is a different link from the first link that uses the first frequency channel. A wireless communication device according to claim 1 or 2, characterized by the above.

4. The aforementioned second Status code is set in the Status Code field included in the Per-STA Profile particular related to the second link. A wireless communication device according to any one of claims 1 to 3.

5. The aforementioned Basic Multi-link element includes a Link Info field. The Per-STA Profile subject relating to the second link is included in the Link Info field. A wireless communication device according to any one of claims 1 to 4.

6. The transmitting means transmits the Association Response frame using the first frequency channel that received the Association Request frame. A wireless communication device according to any one of claims 1 to 5, characterized by the features described herein.

7. The wireless communication device further, The device has processing means for performing a 4-way handshake using the first link with the other wireless communication device. A wireless communication device according to any one of claims 1 to 6, characterized by the features described herein.

8. The processing means generates a GTK (Group Temporary Key) corresponding to the first link, but does not generate a GTK corresponding to the second link. The wireless communication device according to feature 7.

9. The wireless communication device further, The receiving means has an authentication processing means that performs authentication processing with the other wireless communication device before the receiving means receives the Association Request frame. A wireless communication device according to any one of claims 1 to 8.

10. A wireless communication device that performs multilink communication in accordance with the IEEE 802.11 series standard, A transmitting means that transmits an Association Request frame containing first information identifying multiple links to other wireless communication devices on a first frequency channel, If the other wireless communication device accepts the establishment of a wireless communication link for the first link using the first frequency channel among the multiple links identified by the first information, but does not accept the establishment of a wireless communication link for the second link using the second frequency channel, a receiving means receives an Association Response frame from the other wireless communication device, which includes a first Status code and a Basic Multi-link element indicating success. It has, The Basic Multi-link element included in the Association Response frame received by the receiving means is: Including the Per-STA Profile subject related to the second link mentioned above, The Per-STA Profile particular relating to the second link includes a second Status code indicating the cause of the failure. A wireless communication device characterized by the following features.

11. The wireless communication device according to claim 10, characterized in that the Per-STA Profile particular relating to the second link includes a Link ID indicating the second link.

12. The second link is a different link from the first link that uses the first frequency channel. The wireless communication device according to claim 10 or 11, characterized in that it is a wireless communication device.

13. The aforementioned second Status code is set in the Status Code field included in the Per-STA Profile particular related to the second link. A wireless communication device according to any one of claims 10 to 12, characterized by the features described herein.

14. The aforementioned Basic Multi-link element includes a Link Info field. The Per-STA Profile subject relating to the second link is included in the Link Info field. A wireless communication device according to any one of claims 10 to 13, characterized by the features described herein.

15. The receiving means receives the Association Response frame using the first frequency channel from which the Association Request frame was transmitted. A wireless communication device according to any one of claims 10 to 14, characterized by the features described herein.

16. The wireless communication device further, The device has processing means for performing a 4-way handshake using the first link with the other wireless communication device. A wireless communication device according to any one of claims 10 to 15, characterized by the features described herein.

17. The processing means sets a GTK (Group Temporary Key) corresponding to the first link, but does not set a GTK corresponding to the second link. The wireless communication device according to claim 16.

18. The wireless communication device further, The transmission means has an authentication processing means that performs authentication processing with the other wireless communication device before the transmission means transmits the Association Request frame. A wireless communication device according to any one of claims 10 to 17, characterized by the features described herein.

19. A control method for a wireless communication device that performs multilink communication in accordance with the IEEE 802.11 series standard, A receiving step of receiving an Association Request frame containing first information identifying multiple links from another wireless communication device on a first frequency channel, If, among the multiple links identified by the first information, the establishment of a wireless communication link is accepted for the first link using the first frequency channel, but the establishment of a wireless communication link is not accepted for the second link using the second frequency channel, a transmission step of transmitting an Association Response frame including a first Status code and a Basic Multi-link element indicating success to the other wireless communication device, It has, The Basic Multi-link element included in the Association Response frame transmitted by the transmission process is: Including the Per-STA Profile subject related to the second link mentioned above, The Per-STA Profile particular relating to the second link includes a second Status code indicating the cause of the failure. A control method characterized by the following:

20. A control method for a wireless communication device that performs multilink communication in accordance with the IEEE 802.11 series standard, A transmission step of transmitting an Association Request frame containing first information identifying multiple links to other wireless communication devices on a first frequency channel, If the other wireless communication device accepts the establishment of a wireless communication link for the first link using the first frequency channel among the multiple links identified by the first information, but does not accept the establishment of a wireless communication link for the second link using the second frequency channel, the receiving step of receiving an Association Response frame from the other wireless communication device, which includes a first Status code and a Basic Multi-link element indicating success; It has, The Basic Multi-link element included in the Association Response frame received by the receiving process is: Including the Per-STA Profile subject related to the second link mentioned above, The Per-STA Profile particular relating to the second link includes a second Status code indicating the cause of the failure. A control method characterized by the following:

21. A program for causing a computer to function as one of the means of a wireless communication device according to any one of claims 1 to 9.

22. A program for causing a computer to function as one of the means of a wireless communication device according to any one of claims 10 to 18.

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