Communication device, communication method, and storage medium

Abstract

This invention discloses a communication device, a communication method, and a storage medium. The communication device is capable of performing multi-link communication conforming to the IEEE 802.11 standard series. The communication device includes: a connection unit configured to establish a first link and a second link via a channel; and a setting unit configured to, when the communication device established through the connection unit as a connection partner for the first link and the communication device established through the connection unit as a connection partner for the second link are the same, set a pairwise temporary key PTK shared between the communication via the first link and the communication via the second link.

Description

Technical Field

[0001] This invention relates to a communication apparatus and a communication method for wireless communication. Background Technology

[0002] The IEEE 802.11 series is considered to be the standard specification for Wireless Local Area Networks (WLANs) developed by the Institute of Electrical and Electronics Engineers (IEEE). WLAN is an abbreviation for Wireless Local Area Network. The IEEE 802.11 series of standards includes IEEE 802.11a / b / g / n / ac / ax standards.

[0003] Patent document 1 discloses the use of Orthogonal Frequency Division Multiple Access (OFDMA) for wireless communication in compliance with the IEEE 802.11ax standard. The IEEE 802.11ax standard achieves high peak throughput by using OFDMA for wireless communication.

[0004] IEEE has been researching and developing the IEEE 802.11be standard as a new standard in the IEEE 802.11 series to further improve throughput and frequency utilization. Within the IEEE 802.11be standard, research has been ongoing on a technology that allows access points (APs) and stations (STAs) to establish multiple connections via multiple different channels to achieve higher-speed wireless communication.

[0005] Reference List

[0006] Patent documents

[0007] PTL1: Japanese Patent Application Publication No. 2018-50133 Summary of the Invention

[0008] Technical issues

[0009] Each data frame transmitted by the communication device is assigned a sequence number (SN) indicating the order of data transmission. When the receiving order of data frames changes at the receiving side, the SN is used to rearrange the data frames. During data transmission, a pairwise temporary key (PTK) is used as the encryption key. When encrypting data frames using the PTK, a packet number (PN) is added to each data frame. When data frames are rearranged at the receiving side, if the PN assigned to a received data frame is less than the PN of the received data frame, the receiving side determines that a replay attack has occurred and subsequently discards the received data frame.

[0010] In scenarios involving communication via multiple channels, for example, if an error occurs in a data frame transmitted via the first channel, the data frame can be retransmitted via a second channel with good communication quality. In this case, if different PTKs are used between the channels, the PN added during data frame encryption will be inconsistent across the channels.

[0011] When data frames received via multiple channels are rearranged according to their serial number (SN) order, there is a possibility that the PN of a data frame received via the second channel is less than the PN of a data frame received via the first channel. Therefore, there is a possibility that normal data frames received via the second channel may be discarded.

[0012] In view of the above problems, the present invention aims to prevent the dropping of normal data frames in connections established between communication devices via multiple channels.

[0013] Problem Solution

[0014] To achieve the above objectives, the communication device is capable of performing multi-link communication conforming to the IEEE 802.11 standard series. The communication device includes: a connection unit configured to establish a first link and a second link via a channel; and a setting unit configured to set a pairwise temporary key PTK shared between communication via the first link and communication via the second link, provided that the communication device established through the connection unit as a connection partner for the first link is the same as the communication device established through the connection unit as a connection partner for the second link.

[0015] Advantages of the invention

[0016] According to the present invention, communication can be carried out without discarding normal data frames when communicating via multiple channels. Attached Figure Description

[0017] Figure 1 This is a diagram illustrating the network configuration established by the communication device 102.

[0018] Figure 2 This is a diagram illustrating the hardware configuration of communication devices 102 and 103.

[0019] Figure 3 This is a diagram illustrating the functional configuration of communication devices 102 and 103.

[0020] Figure 4 This is a sequence diagram illustrating the multi-link connection processing.

[0021] Figure 5 This is a flowchart of the link connection processing of the communication device 102 shown in the figure.

[0022] Figure 6 This is a flowchart of a first example of the link connection processing of the illustrated communication device 103.

[0023] Figure 7 This is a sequence diagram illustrating the multi-link connection processing.

[0024] Figure 8 This is a flowchart of the link connection processing of the communication device 102 shown in the figure.

[0025] Figure 9 This is a flowchart of the link connection processing of the communication device 103 shown in the figure. Detailed Implementation

[0026] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. The configurations described in the following exemplary embodiments are considered illustrative, and the present invention is not limited to the illustrated configurations.

[0027] Figure 1 The illustration shows the configuration of a network established by communication device 102 according to this exemplary embodiment. Communication device 102 is an access point (AP) that establishes network 101. Network 101 is a wireless network. According to this exemplary embodiment, when communication device 102 establishes multiple networks, all networks share the same Basic Service Set Identifier (BSSID). BSSID is an abbreviation for Basic Service Set Identifier, which serves as a network identifier. Communication device 102 shares the same Service Set Identifier (SSID) with all networks. SSID is an abbreviation for Service Set Identifier, which is used as an AP identifier. This exemplary embodiment uses a single SSID even when communication device 102 establishes multiple connections.

[0028] Communication device 103 is a station (STA) that participates in network 101. Each communication device supporting the IEEE 802.11be standard can conduct wireless communication compliant with the IEEE 802.11be standard via network 101. IEEE is an abbreviation for the Institute of Electrical and Electronics Engineers. EHT is an abbreviation for Extremely High Throughput. EHT can be understood as an abbreviation for Extreme High Throughput. Each communication device can communicate in the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. The frequency band used by each communication device is not limited to the above frequency bands. For example, the communication device can also use different frequency bands such as the 60 GHz band. Each communication device can communicate by using the 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz frequency bands.

[0029] Communication devices 102 and 103 perform Orthogonal Frequency Division Multiple Access (OFDMA) communication conforming to the IEEE 802.11be standard to achieve multi-user (MU) communication that multiplexes signals from multiple users. OFDMA is an abbreviation for Orthogonal Frequency Division Multiple Access. In OFDMA communication, frequency bands called resource units (RUs) are allocated to different STAs in a non-overlapping manner, and the carriers allocated to each STA are orthogonal to each other. Therefore, the AP can communicate in parallel with multiple STAs.

[0030] Communication devices 102 and 103 establish links and perform multi-link communication via multiple channels. A channel is defined in the IEEE 802.11 series of standards and refers to a channel capable of wireless communication conforming to the IEEE 802.11 series of standards. In the IEEE 802.11 series of standards, multiple channels are defined in each of the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. In the IEEE 802.11 series of standards, the bandwidth of each channel is defined as 20 MHz. A bandwidth of 40 MHz or higher can be used within a channel, created by channel bonding of adjacent channels. For example, communication devices 102 and 103 can establish a first link 104 via a first channel in the 2.4 GHz band and a second link 105 via a second channel in the 5 GHz band, thereby communicating with each other via these two links. In this case, communication device 102 keeps the second link 105 via the second channel parallel to the first link 104 via the first channel. Communication device 102 establishes links with communication device 103 via multiple channels in this way, thereby increasing the throughput of communication with communication device 103. Communication devices 102 and 103 can establish multiple links in different frequency bands in multi-link communication. For example, communication devices 102 and 103 can establish a first link 104 in the 2.4 GHz band, a second link 105 in the 5 GHz band, and a third link in the 6 GHz band. Alternatively, communication devices 102 and 103 can establish links via multiple different channels included in the same frequency band. For example, communication devices 102 and 103 can establish a first link 104 via channel 1 in the 2.4 GHz band and a second link 105 via channel 5 in the 2.4 GHz band. Links can also be established in the same frequency band and different frequency bands. For example, in addition to the first link 104 via channel 1 in the 2.4 GHz band and the second link 105 via channel 5 in the 2.4 GHz band, communication devices 102 and 103 can also establish a third link via channel 36 in the 5 GHz band. Establishing multiple connections with communication device 103 in different frequency bands in this manner allows communication device 102 to communicate with communication device 103 in other frequency bands when one frequency band is congested, thereby preventing a decrease in the throughput of communication with communication device 103.

[0031] In multi-link communication, the multiple links established between communication devices 102 and 103 must have different channels. In multi-link communication, the channel spacing between the multiple links established by communication devices 102 and 103 must be greater than 20 MHz. Although communication devices 102 and 103 establish a first link 104 and a second link 105 in this exemplary embodiment, the two communication devices may also establish three or more links.

[0032] In multi-link communication, communication devices 102 and 103 divide a single data set into several parts and transmit these parts to a partner device via multiple links. Alternatively, communication devices 102 and 103 can transmit the same data via each of the multiple links, using communication via one link as backup communication for communication via the others. More specifically, communication device 102 transmits the same data to communication device 103 via a first link via a first channel and a second link via a second channel. In this case, for example, even if an error occurs in communication via the first link, communication device 103 can still receive the data transmitted from communication device 102 because communication device 102 transmits the same data to communication device 103 via the second link. Another option is that communication devices 102 and 103 can use different links depending on the type of frame and data to be communicated. For example, communication device 102 can transmit management frames via the first link and data frames containing data via the second link. More specifically, management frames refer to beacon frames, probe request frames, probe response frames, association request frames, and association response frames. In addition to these frames, deassociation frames, authentication frames, deauthentication frames, and action frames are also called management frames. Beacon frames broadcast network information. Probe request frames request network information. Probe response frames provide network information in response to probe request frames. Association request frames request a connection. Association response frames indicate connection permission or error in response to association request frames. Deassociation frames disconnect a connection. Authentication frames authenticate partner devices. Deauthentication frames cancel the authentication of partner devices and disconnect the connection. Action frames perform additional functions beyond those mentioned above. Communication devices 102 and 103 transmit and receive management frames conforming to the IEEE 802.11 series of standards. Alternatively, when communication device 102 transmits data related to captured images, for example, communication device 102 can transmit metadata such as date, camera parameters (aperture stop and shutter speed), and location information via a first link, and pixel information via a second link.

[0033] Communication devices 102 and 103 can be capable of performing multiple-input multiple-output (MIMO) communication. In this case, communication devices 102 and 103 have multiple antennas, and a single communication device transmits different signals from these antennas using the same channel. The receiving side uses multiple antennas to simultaneously receive all signals from multiple streams, separates the signals in each stream, and decodes the signals. Therefore, within the same time period, communication devices 102 and 103 can communicate more data when performing MIMO communication than when not performing MIMO communication. When performing multi-link communication, communication devices 102 and 103 can perform MIMO communication via certain links.

[0034] Although communication devices 102 and 103 conform to the IEEE 802.11be standard, they may also conform to at least one of the older standards preceding the IEEE 802.11be standard, in addition to the IEEE 802.11be standard. Older standards include the IEEE 802.11a / b / g / n / ac / ax standards. According to this exemplary embodiment, at least one of the IEEE 802.11a / b / g / n / ac / ax / be standards and subsequent standards is referred to as the IEEE 802.11 family of standards. In addition to the IEEE 802.11 family of standards, communication devices 102 and 103 may also conform to other communication standards, such as... Near Field Communication (NFC), Ultra Wideband (UWB), Zigbee, and the Multiband OFDM Alliance (MBOA). UWB is an abbreviation for Ultra Wideband, while MBOA is an abbreviation for Multiband OFDM Alliance. OFDM is an abbreviation for Orthogonal Frequency Division Multiplexing. NFC is an abbreviation for Near Field Communication. UWB includes Wireless USB, Wireless 1394, and Winter. Communication devices 102 and 103 can conform to wired communication standards such as wired LAN.

[0035] While specific examples of communication device 102 include wireless local area network (LAN) routers and personal computers (PCs), the invention is not limited thereto. Communication device 102 can be any communication device capable of multi-link communication with other communication devices. Communication device 102 can also be an information processing device, such as a wireless chip, capable of wireless communication conforming to the IEEE 802.11be standard. While specific examples of communication device 103 include cameras, tablet computers, smartphones, PCs, mobile phones, and video cameras, the invention is not limited thereto. Communication device 103 can be any communication device capable of multi-link communication with other communication devices. Communication device 103 can also be an information processing device, such as a wireless chip, capable of wireless communication conforming to the IEEE 802.11be standard. Figure 1The network in the example includes one access point (AP) and one STA (STA), but the number of APs and STAs is not limited to this. Information processing devices, such as wireless chips, have antennas for transmitting the generated signals.

[0036] Figure 2 The illustration shows the hardware configuration of communication devices 102 and 103 according to this exemplary embodiment. Each of the communication devices 102 and 103 includes a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207.

[0037] Storage unit 201 includes at least one memory such as read-only memory (ROM) and random access memory (RAM), and stores computer programs for implementing various operations (described below) and various information such as communication parameters for wireless communication. ROM is an abbreviation for read-only memory, and RAM is an abbreviation for random access memory. Storage media that can be used as storage unit 201 include not only ROM and RAM, but also storage media such as floppy disks, hard disks, optical disks, magneto-optical disks, optical disc read-only memory (CD-ROM), recordable optical disks (CD-R), magnetic tapes, non-volatile memory cards, and digital versatile optical discs (DVDs). Storage unit 201 may also include multiple memories.

[0038] Control unit 202 includes, for example, at least one processor such as a central processing unit (CPU) and a microprocessor unit (MPU), and executes a computer program stored in storage unit 201 to control the entire communication device 102. Control unit 202 can control the entire communication device 102 through cooperation with an operating system (OS) via the computer program stored in storage unit 201. Control unit 202 generates data and signals (wireless frames) to be transmitted when communicating with other communication devices. CPU is an abbreviation for Central Processing Unit, and MPU is an abbreviation for Microprocessor Unit. Control unit 202 may also include multiple processors such as a multi-core processor, and control the entire communication device 102 by using multiple processors.

[0039] The control unit 202 also controls the functional unit 203 to perform wireless communication, image capture, printing, projection, and other predetermined processes. The functional unit 203 is a hardware component that enables the communication device 102 to perform predetermined processes.

[0040] Input unit 204 receives various operations from the user. Output unit 205 outputs various operations to the user via a monitor screen and a speaker. Operations output by output unit 205 include displaying on the monitor screen and outputting sound from the speaker. Input unit 204 and output unit 205 can be implemented as a single module, such as a touch panel. Each of input unit 204 and output unit 205 can be integrated with communication device 102 or configured separately from communication device 102.

[0041] Communication unit 206 controls wireless communication conforming to the IEEE 802.11be standard. Communication unit 206 can control wireless communication conforming not only to the IEEE 802.11be standard but also to other IEEE 802.11 series standards, and uses, for example, wired LAN to control wired communication. Communication unit 206 controls antenna 207 to transmit and receive wireless communication signals generated by control unit 202. Communication device 102 conforms not only to the IEEE 802.11be standard but also to Near Field Communication (NFC) or... In a standard configuration, communication unit 206 can control wireless communications conforming to these communication standards. When communication device 102 can perform wireless communications conforming to multiple communication standards, communication device 102 may include communication units and antennas conforming to the respective communication standards. Communication device 102 communicates image data, document data, video data, and other data with communication device 103 via communication unit 206. Antenna 207 may be configured separately from or integrated with communication unit 206.

[0042] Antenna 207 supports communication in the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. Although the communication device 102 is provided with one antenna in this exemplary embodiment, the communication device 102 may have different antennas for each frequency band. In the case where the communication device 102 has multiple antennas, the communication device 102 may include a communication unit 206 for supporting each antenna.

[0043] Figure 3 The illustration shows the functional configuration of communication devices 102 and 103 according to this exemplary embodiment. Each of the communication devices 102 and 103 includes a link connection unit 301, an encryption key management unit 302, a media access control (MAC) frame generation unit 303, and a data transmission / reception unit 304.

[0044] Link connection unit 301 is a block that performs connection processing for establishing at least one link for data communication between communication devices 102 and 103. The connection processing specifically includes authentication processing, association processing, and four-way handshake processing (4WHS processing). Through 4WHS processing, the PTK, which serves as the encryption key for unicast communication, and the GTK, which serves as the encryption key for broadcast and multicast communication, are shared by communication devices 102 and 103. PTK is an abbreviation for Paired Temporary Key, and GTK is an abbreviation for Group Temporary Key. When communication device 102 is connected to communication device 103, communication device 102 can establish connections in advance via multiple links, and can also establish connections via different links during communication via predetermined links.

[0045] The encryption key management unit 302 is a block that manages the encryption keys for each link acquired by the link connection unit 301. According to this exemplary embodiment, the encryption key management unit 302 manages the PTK, which is used as an encryption key for unicast communication encryption, and the GTK, which is used as an encryption key for broadcast and multicast communication encryption.

[0046] MAC frame generation unit 303 is a block that generates MAC frames included in various management frames and data frames, such as authentication requests and association requests.

[0047] The data transmission / reception unit 304 transmits radio frames including MAC frames generated by the MAC frame generation unit 303, and receives radio frames from the buddy device.

[0048] Figure 4 This is a sequence diagram of the processing in the case of multi-link connection processing of communication devices 102 and 103. The exemplary embodiment will now be described using an example of two links. For example, in link 1, communication devices 102 and 103 communicate via channel 1 in the 2.4 GHz band in a first channel. In link 2, communication devices 102 and 103 communicate via channel 36 in the 5 GHz band in a second channel.

[0049] The exemplary embodiment will now be described with reference to an example in which the encryption key set in link 1 is set as the encryption key of link 2.

[0050] In step S401, communication devices 102 and 103 perform authentication processing for link 1 in the first channel. Communication device 103 transmits an authentication request frame to issue an authentication request. Then, communication device 102 transmits an authentication response frame as a response to the request. In the case where the peer-to-peer authentication (SAE) method is used in step S401, the authentication request frame and authentication response frame are exchanged several times. SAE is an abbreviation for peer-to-peer authentication.

[0051] In step S402, communication devices 102 and 103 perform association processing for link 1. Communication device 103 transmits an association request frame for connection. Then, communication device 102 transmits an association response frame as a response to the request.

[0052] In step S403, communication devices 102 and 103 perform 4WHS processing to generate an encryption key for communication on Link 1. First, a pairwise master key (PMK) is generated to encrypt communication between communication devices 102 and 103, and the PMK is communicated to communication device 102 from the authentication server. The PMK is used to generate a PTK in the 4WHS processing. Then, communication device 102 exchanges random numbers called Snoc and Anoc with communication device 103 in 4WHS messages 1 and 2, and generates a PTK based on the PMK and these random numbers. The PTK includes three different keys: a key encryption key (KEK), a key confirmation key (KCK), and a temporary key (TK). The TK is used for encryption in unicast communication, while the KCK is used for encryption in broadcast or multicast communication. In 4WHS message 3, communication device 102 transmits the GTK generated by communication device 102 to share the GTK between communication devices 102 and 103. Following step S403, in step S404, communication device 102 sets the PTK generated in step S403 and used as the encryption key for unicast communication as the PTK of link 1 to the wireless chip. Similarly, in step S405, communication device 103 also sets the PTK of link 1 to the wireless chip.

[0053] Subsequently, after establishing link 1, communication devices 102 and 103, with the connection established via link 1, perform connection processing for link 2. The connection processing for link 2 can be performed immediately after the connection processing for link 1, or after a predetermined time period. The processes in steps S411, S412, and S413 are similar to those in steps S401, S402, and S403, respectively. Since PTK is generated using random numbers, a different PTK is obtained than the PTK obtained in step S403. However, in step S414, if an established link exists, communication device 102 sets the PTK set in link 1 to the PTK of link 2, instead of using the PTK obtained in step S413. Similarly, in step S415, communication device 103 also sets the PTK of link 1 to the PTK of link 2. As described above, in the case of multiple link connections, PTK can be shared between links. Shared encryption keys include copied encryption keys.

[0054] Figure 5This is a flowchart illustrating the process by which the control unit 202 executes a program stored in the storage unit 201 of the communication device 102 to determine the PTK to be set to the link.

[0055] The process begins when the communication device 102 is powered on. Alternatively, the communication device 102 may begin processing in response to receiving an instruction from a user or application to initiate multi-link communication. Yet another option is that the communication device 102 may begin processing when the amount of data to be communicated with a partner device becomes a predetermined threshold or greater.

[0056] In step S501, communication device 102 receives an authentication request frame from communication device 103 via link 1 and obtains information for identifying the communication device. This identification information is used to determine whether a link has been established with communication device 103. Examples of identification information include a multi-link device ID (MLD ID), but the invention is not limited thereto. In step S502, in response to the authentication request frame received in step S501, communication device 102 transmits an authentication response frame to communication device 103 for authentication processing. After the authentication processing is completed, in step S503, in response to an association request frame received from communication device 103, communication device 102 performs processing for transmitting an association response frame to communication device 103. After the association processing is completed, in step S504, communication device 102 and communication device 103 perform 4WHS processing to generate a PTK used as an encryption key. In step S505, communication device 102 determines whether the communication device established via link 1 is the same as the communication device established via link 2. Since there is no communication device that previously established a connection, in step S506, communication device 102 sets the PTK obtained in link 1 as the PTK of link 1 to the wireless chip. This completes the connection process of link 1.

[0057] Then, in step S501, communication device 102 receives an authentication request frame from communication device 103 via link 2 and obtains information for identifying the communication device. This identification information is used to determine whether a link has been established with communication device 103. In step S502, in response to the authentication request frame received in step S501, communication device 102 transmits an authentication response frame to communication device 103 for authentication processing. After completing the authentication processing, in step S503, in response to an association request frame received from communication device 103, communication device 102 performs processing for transmitting an association response frame to communication device 103. After completing the association processing, in step S504, communication device 102 and communication device 103 perform 4WHS processing to generate PTK, which is used as an encryption key. In step S505, communication device 102 determines whether the communication device established via link 1 is the same as the communication device established via link 2. More specifically, the communication device 102 determines whether the identification information of the communication device included in the authentication request frame in step S501 is consistent with the identification information of the communication device that has already established a connection with Link 1. If it is determined that the communication devices are the same communication device ("Yes" in step S505), in step S507, the communication device 102 sets the PTK set in Link 1 as the PTK of Link 2. In step S507, the communication device 102 sets the PTK of Link 1 as the PTK of Link 2 to the wireless chip, instead of using the PTK generated in the 4WHS process of Link 2. If it is determined that the communication devices are not the same communication device ("No" in step S505), in step S506, the communication device 102 sets the PTK generated for Link 2 in the 4WHS process as the PTK of Link 2 to the wireless chip. In step S506, the PTK generated for Link 2 in the 4WHS process is set as the PTK for the connection link to the encryption key management unit 302. This completes the connection process of Link 2.

[0058] Figure 6 This is a flowchart illustrating the process by which the control unit 202 executes a program stored in the storage unit 201 of the communication device 103 to determine the PTK to be set to the link.

[0059] Processing begins when the communication device 103 is powered on. Alternatively, the communication device 103 may begin processing in response to a command to initiate multi-link communication received from a user or application. Yet another option is that the communication device 103 may begin processing when the amount of data to be communicated with a partner device becomes a predetermined threshold or greater.

[0060] In step S601, communication device 103 stores identification information about communication device 102 in an authentication request frame within link 1. This information is used to determine whether a link has been established with communication device 102. When a user selects communication device 102 as the connection destination using a user interface (UI) and initiates a connection, or when communication device 103 scans, finds communication device 102 as the connection destination, and automatically initiates a connection, communication device 103 acquires identification information about communication device 102. In step S602, communication device 103 performs processing to transmit the authentication request frame set in step S601 and receives an authentication response frame from communication device 102. After completing the authentication processing, in step S603, communication device 102 performs processing to transmit an association request frame and receives an association response frame from communication device 102. After completing the association processing, in step S604, communication device 103 and communication device 102 perform 4WHS processing to generate a PTK used as an encryption key. In step S605, the communication device 103 determines whether the communication device that established the connection via link 1 is the same as the communication device that established the connection via link 2. Since there is no communication device that previously established a connection, in step S606, the communication device 103 sets the PTK obtained in link 1 as the PTK of link 1 to the wireless chip. This completes the connection process of link 1.

[0061] Then, in step S601, communication device 103 stores identification information about communication device 102 in an authentication request frame on link 2. This information is used to determine whether the link has been connected to communication device 102. In step S602, communication device 103 performs processing for transmitting the authentication request frame set in step S601 and receiving an authentication response frame from communication device 102. After completing the authentication processing, in step S603, communication device 103 performs processing for transmitting an association request frame and receiving an association response frame from communication device 102. After completing the association processing, in step S604, communication device 103 and communication device 102 perform 4WHS processing to generate PTK as an encryption key. In step S605, communication device 103 determines whether the communication device connected via link 1 is the same as the communication device connected via link 2. More specifically, communication device 103 determines whether the identification information about communication device 102 set in the authentication request frame in step S601 is consistent with the identification information about communication device 102 that has been connected via link 2. If it is determined that the communication devices are the same communication devices ("Yes" in step S605), in step S607, communication device 103 sets the PTK set in link 1 as the PTK of link 2. On the other hand, if it is determined that the communication devices are not the same communication devices ("No" in step S605), in step S606, communication device 103 sets the PTK generated for link 2 in the 4WHS process as the PTK of link 2 to the wireless chip. In step S606, communication device 102 sets the PTK generated for link 2 in the 4WHS process as the PTK of link 2 to the encryption key management unit 302.

[0062] Although identification information about the communication device is stored in the authentication request frame in this exemplary embodiment, the identification information may also be stored, for example, in the association request frame.

[0063] According to this exemplary embodiment, when it is determined that the same communication device has established a connection via link 1 and a connection via link 2, the PTK can be shared between the links by setting the encryption key set in link 1 as the encryption key of link 2. Using the PTK shared between link 1 and link 2 enables communication without dropping normal data frames.

[0064] [Second Exemplary Embodiment]

[0065] Figure 7This is a sequence diagram of the processing in the case where communication devices 102 and 103 perform multi-link connection processing. The second exemplary embodiment will now be described with reference to the case using two links. For example, in link 1, communication devices 102 and 103 communicate via channel 1 in the 2.4 GHz band in a first channel. In link 2, communication devices 102 and 103 communicate via channel 36 in the 5 GHz band in a second channel.

[0066] The exemplary embodiment will now be described in relation to a method of sharing a PTK between links by resetting the PTK of link 1 using a PTK set in link 2.

[0067] The connection processing for link 1 in steps S701 to S713 is respectively related to... Figure 4 The processes in steps S401 to S413 are similar, so redundant descriptions will be omitted. As a result of the process in step S713, even if a different PTK is obtained than the PTK obtained in step S703, communication device 102 still sets the PTK of link 2 as the PTK of link 2 in step S714, and resets the PTK of link 1 using the PTK of link 2 in step S716. Similarly, communication device 103 sets the PTK of link 2 as the PTK of link 2 in step S715, and resets the PTK of link 1 using the PTK of link 2 in step S717. As described above, when performing multi-link connections, PTKs can be shared between links. Shared encryption keys include copied encryption keys.

[0068] Figure 8 This is a flowchart illustrating the process by which the control unit 202 executes a program stored in the storage unit 201 of the communication device 102 to determine the PTK to be set to the link. The processes in steps S801 to S804 are respectively related to... Figure 5 The processing in steps S501 to S504 is similar, so redundant descriptions will be omitted.

[0069] In step S801, communication device 102 receives an authentication request frame from communication device 103 via link 1 and obtains information for identifying the communication device. This identification information is used to determine whether a link has been established with communication device 103. Examples of identification information include a multi-link device ID (MLD ID), but the invention is not limited thereto. In step S802, in response to the authentication request frame received in step S801, communication device 102 transmits an authentication response frame to communication device 103 for authentication processing. After completing the authentication processing, in step S803, communication device 102 performs processing to receive an association request frame from communication device 103 and transmit an association response frame to communication device 103. After completing the association processing, in step S804, communication device 102 and communication device 103 perform 4WHS processing to generate a PTK used as an encryption key. In step S805, communication device 102 determines whether the communication device established via link 1 is the same as the communication device established via link 2. Since there is no communication device that previously established a connection, in step S809, communication device 102 sets the PTK set in link 1 as the PTK of link 1 to the wireless chip. This completes the connection processing for link 1.

[0070] Then, in step S801, communication device 102 receives an authentication request frame from communication device 103 in link 2 and obtains information for identifying the communication device. Steps S801 to S804 in link 2 are as described above. In step S805, communication device 102 determines whether the communication device established via link 1 is the same as communication device 2 established via link 2. More specifically, communication device 102 determines whether the identification information about the communication device set in the authentication request frame in step S801 is consistent with the identification information about the communication device that has already established a connection via link 1. If it is determined that the communication devices are the same communication device ("yes" in step S805), in step S806, communication device 103 determines whether data communication is currently being conducted via link 1. If communication device 102 determines that data communication is currently being conducted via link 1 ("yes" in step S806), in step S807, communication device 103 sets the PTK of link 1 as the PTK of link 2 to the wireless chip without updating the PTK of the link currently conducting data communication. This is because updating the PTK of the currently communicating link would interrupt data communication. If communication device 102 determines that no data communication is currently occurring via link 1 ("No" in step S806), in step S808, communication device 102 sets the PTK generated for link 2 in the 4WHS process as the PTK of link 1 to the wireless chip. In step S809, communication device 102 further sets the PTK generated for link 2 in the 4WHS process as the PTK of link 2 to the wireless chip. If it is determined that the communication devices are not the same communication device ("No" in step S805), in step S809, communication device 102 sets the PTK generated for link 2 in the 4WHS process as the PTK of link 2 to the wireless chip.

[0071] Although identification information about the communication device is stored in the authentication request frame in this exemplary embodiment, the information may also be stored in a different frame, for example, in the association request frame.

[0072] Figure 9 This is a flowchart illustrating the process by which the control unit 202 executes a program stored in the storage unit 201 of the communication device 103 to determine the PTK to be set to the link.

[0073] The processing of link 1 in steps S901 to S904 is respectively related to Figure 6 The processing in steps S601 to S604 is similar, so redundant descriptions will be omitted.

[0074] In step S901, communication device 103 stores identification information about communication device 102 in an authentication request frame in link 1. This information is used to determine whether a link with communication device 102 has been established. When a user selects communication device 102 as the connection destination using a user interface (UI) and initiates a connection, or when communication device 103 scans, finds communication device 102 as the connection destination, and automatically initiates a connection, communication device 103 acquires identification information about communication device 102. In step S902, communication device 103 performs processing to transmit the authentication request frame set in step S901 and receive an authentication response frame from communication device 102. After completing the authentication processing, in step S903, communication device 103 performs processing to transmit an association request frame and receive an association response frame from communication device 102. After completing the association processing, in step S904, communication device 103 and communication device 102 perform 4WHS processing to generate PTK, which is used as an encryption key. In step S905, the communication device 103 determines whether the communication device that established the connection via link 1 is the same as the communication device that established the connection via link 2. Since there is no communication device that previously established a connection, in step S909, the communication device 103 sets the PTK obtained in link 1 as the PTK of link 1 to the wireless chip. This completes the connection process of link 1.

[0075] Then, in step S901, the communication device 103 stores the identification information of the communication device 102 in the authentication request frame of link 2. According to this exemplary embodiment, the processing for link 2 in steps S902 to S904 is similar to the processing for link 1 in steps S902 to S904, therefore redundant descriptions will be omitted.

[0076] In step S905, communication device 103 determines whether the communication device that established a connection via link 1 is the same as the communication device that established a connection via link 2. More specifically, communication device 103 determines whether the identification information about communication device 102 set in the authentication request frame in step S901 is consistent with the identification information about the communication device that has already established a connection via link 2. If it is determined that the communication devices are the same communication device ("Yes" in step S905), in step S906, communication device 103 determines whether data communication is currently taking place on link 1. If communication device 103 determines that data communication is currently taking place on link 1 ("Yes" in step S906), in step S907, communication device 103 sets the PTK of link 2 (link 2) to the wireless chip without updating the PTK of the link currently conducting data communication. This is because updating the PTK of the link currently conducting data communication would interrupt data communication. If communication device 103 determines that no data communication is currently occurring on link 1 ("No" in step S906), in step S908, communication device 103 sets the PTK generated in the 4WHS processing for link 2 as the PTK for link 1 to the wireless chip. In step S909, communication device 102 sets the PTK generated in the 4WHS processing for link 2 as the PTK for link 2 to the wireless chip. If it is determined that the communication devices are not the same communication device ("No" in step S905), in step S909, communication device 103 sets the PTK generated in the 4WHS processing for link 2 as the PTK for link 2 to the wireless chip.

[0077] Although in this exemplary embodiment, the identification information of the communication device is stored in the authentication request frame, the information may be stored in a different frame, for example, in the association request frame.

[0078] According to this exemplary embodiment, when it is determined that the same communication device has established a connection via link 1 and a connection via link 2, the same PTK can be used between links by setting the encryption key generated in link 2 as the encryption key of link 1. If communication is currently in progress on link 1, setting the encryption key of link 1 as the encryption key of link 2 prevents communication interruption, thereby allowing the use of the same PTK between links. Furthermore, using a PTK shared between links enables communication without discarding normal data frames.

[0079] According to this exemplary embodiment, 4WHS processing shares not only the PTK but also the GTK. However, since a different GTK is required for each link, communication devices 102 and 103 perform 4WHS processing when establishing a new connection in each link.

[0080] A recording medium storing program code for software to implement the above-described functions can be provided to the system or apparatus, and the computer (CPU or MPU) of the system or apparatus can read and execute the program code stored in the recording medium. In this case, the program code read from the storage medium itself implements the functions of the exemplary embodiments described above, and the storage medium storing the program code is configured in the apparatus described above.

[0081] Examples of available storage media for providing program code include floppy disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, ROMs, and DVDs.

[0082] The above functions can be implemented not only when the computer executes and reads program code, but also when the operating system (OS) performs some or all of the actual processing on the computer based on the instructions of the program code. OS is an abbreviation for Operating System.

[0083] Furthermore, the program code read from the storage medium is written into the memory included in a function expansion board plugged into the computer or a function expansion unit connected to the computer. The CPU included in the function expansion board or function expansion unit can implement the above functions by executing some or all of the actual processing through instructions based on the program code.

[0084] The present invention can also be implemented when a program for implementing at least one function of the exemplary embodiments described above is provided to a system or apparatus via a network or storage medium, and at least one processor in the computer of the system or apparatus reads and executes the program. Furthermore, the present invention can also be implemented by a circuit (e.g., an application-specific integrated circuit (ASIC)) that implements at least one function.

[0085] This invention is not limited to the exemplary embodiments described above, and modifications and changes can be made in various ways without departing from the spirit and scope of the invention. Therefore, the appended claims disclose the scope of the invention.

[0086] This application claims the benefit of Japanese Patent Application Publication No. 2020-103908, filed on June 16, 2020, the entire contents of which are incorporated herein by reference.

Claims

1. A communication device capable of performing multi-link communication conforming to the IEEE 802.11 standard series, the communication device comprising: A connection unit configured to establish a first link on a first channel and a second link on a second channel; A receiving unit is configured to receive a request frame to request the establishment of a second link with another communication device when the communication device has already established a first link with a first other communication device. as well as A control unit configured to control the use of a shared pairwise temporary key in both communication on the first link and communication on the second link when the first multi-link device identification information included in the request frame is the same as the second multi-link device identification information that identifies the first other communication device, and to use different pairwise temporary keys in both communication on the first link and communication on the second link when the first multi-link device identification information is different from the second multi-link device identification information.

2. The communication apparatus according to claim 1, wherein If the first multi-link device identification information is the same as the second multi-link device identification information, the control unit will set the pairwise temporary key set in the first link as the pairwise temporary key to be used in the second link.

3. The communication apparatus according to claim 1, wherein If the first multi-link device identification information is the same as the second multi-link device identification information and communication is currently taking place via the first link, the control unit will set the pairwise temporary key set in the first link as the pairwise temporary key to be used in the second link.

4. The communication apparatus according to claim 1, wherein If the first multi-link device identification information is different from the second multi-link device identification information, the control unit will set the pairwise temporary key generated in the second link as the pairwise temporary key to be used in the second link.

5. The communication device according to claim 1, further comprising: The determining unit is configured to determine, based on the first multi-link device identification information included in the request frame and the second multi-link device identification information used to identify the first other communication device, whether the first other communication device, which is a connection partner in the first link, is the same as the communication device, which is a connection partner in the second link.

6. The communication device according to claim 1, further comprising: The sending unit is configured to send management frames used to store the identification information of the multi-link device.

7. The communication device according to claim 1, wherein the identification information is a multi-link device ID.

8. The communication apparatus according to claim 1, wherein The paired temporary keys are generated by performing a four-way handshake process.

9. A communication method for a communication device, the communication device being capable of performing multi-link communication conforming to the IEEE 802.11 standard series, the method comprising: Establish the first link on the first channel and the second link on the second channel; If the communication device has already established the first link with the first other communication device, a request frame is received to request the establishment of the second link with the other communication device. as well as Control is implemented such that, if the first multi-link device identification information included in the request frame is the same as the second multi-link device identification information that identifies the first other communication device, a shared pair of temporary keys are used in both the communication on the first link and the communication on the second link; and if the first multi-link device identification information is different from the second multi-link device identification information, different pair of temporary keys are used in both the communication on the first link and the communication on the second link.

10. A non-transitory computer-readable storage medium storing a program for enabling a computer to function as each unit of a communication apparatus according to any one of claims 1 to 8.

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