JP6597976B2 - Peripheral device relay device and image display system - Google Patents

Description

  The present invention relates to a technique for directly wirelessly connecting to a specific peripheral device relay apparatus in a network constructed using a plurality of relay apparatuses (peripheral device relay apparatuses).

  There is a description of a peripheral device server device that uses USBoverIP technology to control peripheral devices and exchange data from a PC at a remote location via a wired or wireless network (Non-Patent Document 1). When there are a plurality of such peripheral device servers on the network, the PC user can use the connection tool to select a peripheral device to be used and a relay device corresponding to the peripheral device.

  On the other hand, in recent years, in the field of education, with the spread of portable communication terminals such as tablet PCs (Personal Computers), a plurality of communication given to the instructor (teacher) communication terminal and each learner (student) Increasingly, a network is constructed by wireless communication (wireless LAN or the like) using a terminal. In such a system, the USB over IP technology in the above-described peripheral device server apparatus is applied, and a large display (also referred to as a large display apparatus) is connected to the large-sized display (also referred to as a large display apparatus) on the screen of the instructor's communication terminal. The instructor and the learner can share information, such as projecting the screen content displayed on the screen and displaying the list of the screen content of the learner's communication terminal participating in the class on the instructor's communication terminal. ing. Such an apparatus is called an image transfer apparatus.

  In addition, each classroom has an image transfer device and a large display device connected by wire, and the image transfer devices in each classroom can be connected from a remote location (for example, a staff room) by building a wired network with each other. When a tool is used to connect to an image transfer device in an arbitrary classroom, information on the leader's communication terminal can be displayed on a large display device connected to the image transfer device.

  In the above system, the image transfer apparatus has a wireless relay function (wireless access point function) (hereinafter, the image transfer apparatus having the wireless relay function is referred to as “image relay apparatus”), and a wireless access point is installed in the facility. When properly installed, the instructor can connect to the image relay apparatus from anywhere in the school using wireless communication. The image relay device can also display the image data transmitted from the communication terminal via another relay device on a large display device connected to the image relay device. To repeat, if there are multiple such image relay devices on the network (for example, each classroom is equipped), the instructor uses the connection tool to select the image relay device he wants to use and the corresponding large display device. You can choose.

  Here, in the above system, multiple image relay devices and wireless access points are installed in each classroom, so it is necessary for wireless connection processing to reduce the labor for system construction and roaming when using wireless communication. Often, the same service set identifier (SSID) is used. Hereinafter, the SSID shared in the network is also referred to as a general-purpose SSID.

  However, in the above system, when the same general-purpose SSID is set and operated for each relay device, there are a plurality of wireless communication connection destination candidates, and the user's communication terminal selects the image relay device selected from the connection tool. Problems may arise when wirelessly connected to a different image relay apparatus. For example, consider a case where there are a first image relay device (device that a user wants to connect to) and a second image relay device (device other than the device that the user wants to connect to). There may be a case where the communication terminal is unintentionally wirelessly connected to the second image relay device and controls the large display device connected to the first image relay device via this. In addition, when a device connected to the second image relay device is also controlled from another communication terminal, a load is applied to the network communication band, so that the user can comfortably use the large display device from the communication terminal through the network. There is a problem that cannot be done.

  In addition, when the second image relay device has a higher received signal strength (hereinafter referred to as RSSI (Received Signal Strength Indication)) at the communication terminal than the first image relay device to which the communication terminal wants to connect, communication is performed. The terminal attempts to connect to the second image relay device. The connection process (association process) succeeds because the SSID is the same, but if the authentication key is different for each device, the authentication process subsequently fails. As described above, it may happen that the wireless connection process is not performed between the first image relay device and the communication terminal that is desired to be connected. To solve this problem, if the authentication process fails after the connection process of a device other than the device that you want to connect succeeds, exclude the device other than the device that you want to connect from the connection attempt target, It is disclosed that it is excluded from trial. (See Patent Document 1.)

JP 2011-049701 A

Silex Technology Co., Ltd. website <http://www.silex.jp/products/usbdeviceserver/sxds3000wan.html>

  However, in the above-described network construction, when PSK is unified so that the authentication process is successful, in Patent Document 1, when a communication terminal is connected to an image relay device that is not intended by the user, In other words, the operability at the communication terminal is reduced due to a decrease in radio wave reception signal strength, and the network communication band is overloaded when another user controls the device connected to the second image relay device. Therefore, the problem that the large display device cannot be comfortably used has not been solved.

  The present invention has been made in view of the above-described problems. In a wireless network in which a plurality of wireless relay devices are configured with the same SSID, only the specific image relay device desired by the user is wirelessly connected and communicated. The purpose is to do. More generally, in a wireless network in which a plurality of wireless relay devices are configured with the same SSID, the purpose is to perform direct wireless connection and communication only with a specific relay device (peripheral device relay device) desired by the user. To do.

In order to solve the above-described problem, a peripheral device relay apparatus according to one aspect of the present invention is connected to a communication terminal and a network connected to the communication terminal, and relays communication between the peripheral device connected to the communication terminal and the communication terminal. It is a peripheral device relay device in an image display system in which a plurality of peripheral device relay devices are connected via a wired network, and determines whether or not a direct wireless connection request from a communication terminal has been received via the wired network. Based on a wired communication unit, a receiving unit that obtains the time when a direct wireless connection request is received , a storage unit that stores a unique identifier and a seed value for identifying itself, and a unique identifier extracted from the direct wireless connection request networks based on a determination unit that determines whether the requested or not addressed to the own apparatus, a unique identifier, a time of receiving the seed value and direct wireless connection request to Comprising a generator for generating a click identifier, and a transmission unit for transmitting a network identifier and a seed value as response data direct wireless connection request.

  Accordingly, the peripheral device relay apparatus that has received a request from a specific communication terminal can generate a dedicated network identifier and perform direct wireless connection with the communication terminal. The peripheral device relay device means a wireless relay device (wireless access point) having a USB over IP function. The direct wireless connection request literally means a request for wireless connection without going through another wireless relay device or a wired network.

  Also, the uniquely determined information used for the network identifier is preferably an encrypted code. This makes it difficult for other communication terminals or the like to divert the network identifier.

  Furthermore, it is more desirable that the uniquely determined information includes the time at which the peripheral device relay apparatus receives the direct wireless connection request. Thus, duplication of network identifiers can be avoided, and time management (connection time and the like) related to wireless communication with the communication terminal can be performed.

An image display system according to an aspect of the present invention includes a communication terminal and a plurality of image relay apparatuses that are network-connected to the communication terminal and display image data transmitted from the communication terminal on the display apparatus connected to the communication terminal. Are image display systems connected to each other via a wired network, and when a communication terminal specifies an image relay device that controls a desired display device among a plurality of image relay devices, the communication terminal directly connects to the image relay device wirelessly. The image relay device periodically transmits a request, and the image relay apparatus determines whether the direct wireless connection request from the communication terminal is received via the wired network, and the time when the direct wireless connection request is received. a receiving unit that acquires a storage unit for storing a unique identifier and a seed value that identifies itself, its own device a unique identifier extracted from the direct wireless connection request based on A request determines whether the determination of a unique identifier, based on the time of receiving the seed value and direct wireless connection request, and transmits a generating unit for generating a network identifier, a network identifier and a seed value A transmission unit, and when receiving a wireless connection request directly from the wireless terminal, it responds to the wireless terminal with a network identifier and a seed value.

  Thus, when the user of the communication terminal specifies an arbitrary image relay device for image display, the communication terminal immediately transmits a direct wireless connection request periodically. The image relay apparatus that has received this request from a specific communication terminal generates a dedicated network identifier for performing direct wireless communication with the communication terminal, and automatically establishes a direct connection when an environment capable of direct wireless communication is established. Can do.

  The image relay device means a peripheral device relay device having a function of connecting a display device and displaying an image on a communication terminal via a network.

  In the present invention, even when a network is constructed by a plurality of peripheral device relay devices and operated with the same general-purpose SSID, the peripheral device relay device to which the user wants to connect dynamically generates a dedicated SSID, thereby enabling the user to Can directly communicate between the terminal used by the device and its peripheral device relay apparatus.

FIG. 1 is an overall system diagram according to an embodiment of the present invention. FIG. 2 is a hardware configuration of the image relay apparatus according to the embodiment of the present invention. FIG. 3 is a functional block diagram of the image relay apparatus according to the embodiment of the present invention. FIG. 4 is a functional block diagram of the communication terminal according to the embodiment of the present invention. FIG. 5 is an operation flow diagram of the image relay apparatus according to the embodiment of the present invention. FIG. 6 is an operation flowchart of the communication terminal according to the embodiment of the present invention. FIG. 7 is an operation sequence diagram of the system according to the embodiment of the present invention. FIG. 8 is an overall system diagram according to another embodiment of the present invention.

  Hereinafter, embodiments will be specifically described with reference to the drawings.

  Numerical values, constituent elements, arrangement positions of constituent elements, and the like shown in the following embodiments are merely examples, and various modifications and changes can be made within the scope of the invention. In particular, an image relay device will be described as an example, that is, an example in which an image in a communication terminal is displayed on a display device connected to a peripheral device relay device, but the present invention is limited to image display as will be described later. It is not a thing.

(Embodiment)
FIG. 1 is an overall view of a relay system according to an embodiment of the present invention.

  As shown in FIG. 1, the relay system 100 according to the embodiment of the present invention includes devices such as an image relay device N1, a communication terminal T1, a relay device A1, and a large display device D1.

  As shown in FIG. 1, the relay system 100 according to the embodiment of the present invention includes an image relay device N1, a communication terminal T1, and a large display device D1 installed in a classroom A and an image relay in a classroom B in a school. A system in which the device N2, the communication terminal T2, and the large display device D2 are installed and the relay device A1 is installed in the hallway will be described as an example. The image relay apparatuses N1 and N2 here are required to have a USB over IP function, but the relay apparatus A1 has a wireless access point function as a main function, and the USB over IP function is not essential.

  The image relay apparatus N1 includes a USB (Universal Serial Bus, registered trademark) interface and an HDMI (High-Definition Multimedia Interface, registered trademark) interface, and both a wired communication interface and a wireless communication interface as a network (LAN) interface. I have. The image relay device N1 is connected to the image relay device N2 and the relay device A1 by a wired network L1. Further, the image relay device N1 is locally connected to the large display device D1 by a wired cable C1. The wired cable C1 is, for example, a USB cable or an HDMI cable. A user of the communication terminal T1 instructs the image relay apparatus N1 using an application (not shown, hereinafter also referred to as an image display connection tool) provided in the communication terminal T1, thereby locally connecting to the image relay apparatus N1. The display device D1 can be controlled over the network.

  The image relay apparatus N1 can operate a plurality of SSIDs (multi-SSID function). In addition, the image relay apparatus N1 is configured so that the user cannot operate at least one SSID. This is because it is a specification for ensuring that at least one dedicated SSID, which will be described in detail later, can be used.

  Further, the image relay apparatus N1 includes a USB connector, and can connect a USB device (for example, a USB printer) and use the printer from the communication terminal T1.

  The communication terminal T1 includes a wireless interface, and is, for example, a notebook PC, a tablet, or a smartphone. The communication terminal T1 has a USB over IP function for displaying an image via a network, and also includes a connection tool. In addition, the communication terminal T1 may include various interfaces such as a wired LAN connector, which is not essential in the present invention.

  The communication terminal T1 can wirelessly communicate with the image relay device N1 through the wireless network from the wireless interface, and can control the large display device D1. Further, the communication terminal T1 can communicate with the image relay devices N1 and N2 via the wired network L1 directly or via the relay device A1, and can control the large display devices D1 and D2 that are locally connected to each other. The wireless network is realized by a wireless LAN conforming to, for example, the IEEE 802.11 standard.

  The relay device A1 includes a wired interface and a wireless interface, performs wired communication with the image relay devices N1 and N2 through the wired network L1, and performs wireless communication with the communication terminal T1 through the wireless communication path W1. The relay device A1 can wirelessly connect between the communication terminal and the image relay device, or can be connected to another network (such as a wired network). Note that the wireless communication is realized by a wireless LAN that conforms to, for example, the IEEE 802.11 standard, and the wired communication is realized by, for example, one that conforms to the IEEE 802.3 standard.

  The large display device D1 is locally connected to the image relay device N1 by a wired cable C1 (USB cable, HDMI cable, etc.), and is, for example, a large projector, a large monitor device, or the like. Since the wired cable C2 is equivalent to the wired cable C1, detailed description is omitted.

  FIG. 2 is a hardware configuration diagram of the image relay device N1 and the communication terminal T1 according to the embodiment of the present invention. The image relay apparatus N2 has the same hardware configuration as the image relay apparatus N1, and detailed description thereof is omitted.

  As shown in FIG. 2, these devices include a CPU (Central Processing Unit) 20, a ROM (Read Only Memory) 21, a RAM (Random Access Memory) 22, a storage device 23, an external output I / F 24, a WNIC (Wireless Network Interface). Card) 25, NIC (Network Interface Card) 26, and an internal bus 27 for connecting the components. Note that the communication terminal T1 does not necessarily include the external output I / F 24 and the NIC 26.

  The CPU 20 is a processor that executes a control program stored in the ROM 21.

  The ROM 21 is a read-only storage area that holds a control program and the like.

  The RAM 22 is a storage area used as a work area used when the CPU 20 executes a control program.

  The storage device 23 is a storage area for storing a control program, control information, device information, authentication information, or the like.

  The external output I / F 24 includes an interface that can output an image and / or a moving image. For example, the external output I / F 24 has a connector conforming to the USB standard, and performs communication control with a USB device connected to the connector, or has a connector conforming to the HDMI standard, and is connected through the connector. Control communication with the HDMI device. Further, the external output I / F 24 may have both of the connectors and perform communication control with each device.

  The WNIC 25 includes a wireless communication interface that performs wireless communication. For example, a wireless LAN communication interface conforming to the IEEE802.11a, b, g, n, and ac standards.

  The NIC 26 includes a wired communication interface that performs wired communication. For example, a wired LAN communication interface conforming to the IEEE 802.3 standard or the like.

  The internal bus 27 is a bus that electrically connects the CPU 20, ROM 21, RAM 22, storage device 23, external output I / F 24, WNIC 25, and NIC 26 to exchange signals.

  FIG. 3 is a functional block diagram of the image relay apparatus N1 according to the embodiment of the present invention.

  The image relay apparatus N1 illustrated in FIG. 3 includes a wireless communication unit 30, a wired communication unit 31, a communication control unit 32, a storage unit 33, a determination unit 34, a generation unit 35, an encryption key generation unit 36, and the like.

  The wireless communication unit 30 performs wireless communication with a device including each wireless device in the system using a general-purpose SSID. In addition, the wireless communication unit 30 directly performs wireless communication with the communication terminal T1 using a dedicated SSID generated using a request for direct wireless connection from the communication terminal T1 as a trigger. The wireless communication unit 30 is realized by the CPU 20, the ROM 21, the RAM 22, the WNIC 25, and the like.

  The wired communication unit 31 determines whether or not a direct wireless connection request has been received from the communication terminal T1, and notifies the communication control unit 32 of the result. Here, the direct wireless connection request is a request transmitted by broadcast communication from the communication terminal T1 to each image relay device in the wired network L1 via the relay device A1. Further, the wired communication unit 31 determines whether a request for a dedicated SSID for connection with itself is received from the communication terminal T1, and notifies the communication control unit 32 of the result. In many cases, a direct wireless connection request or a dedicated SSID request is received via a wire via the relay device A1, but may be received via wireless, and in that case, it is received by a wireless communication unit. The wired communication unit 31 is realized by the CPU 20, the ROM 21, the RAM 22, the NIC 26, and the like.

  The communication control unit 32 controls communication with the communication terminal T1 through wired communication or wireless communication performed through the wired network L1. The communication control unit 32 includes a reception unit 321 and a transmission unit 322. The communication control unit 32 is realized by the CPU 20, the ROM 21, the RAM 22, the storage device 23, and the like.

  The reception unit 321 receives the direct wireless connection request and transmits it to the determination unit 34. In addition, the receiving unit 321 acquires a time (hereinafter also referred to as a connection request reception time) at which a direct wireless connection request is received from the communication terminal T1 from a timer (not shown) provided in the image relay device, and stores it in the storage unit 33. The receiving unit 321 is realized by the CPU 20, the ROM 21, the RAM 22, the storage device 23, and the like.

  Based on the notification from the determination unit 34, the transmission unit 322 responds directly to the communication terminal T1 with a wireless connection request. Specifically, its own status is returned to the communication terminal T1. In addition, the transmission unit 322 collects the dedicated SSID generated by the generation unit 35 and the encryption key (hereinafter also referred to as a seed value) necessary for generating the encryption key stored in the storage unit 33, to the communication terminal T1. Send. The transmission unit 322 is realized by the CPU 20, the ROM 21, the RAM 22, the storage device 23, and the like.

  The storage unit 33 is a general-purpose SSID used in the relay system, a dedicated SSID generated by the generation unit 35, a seed value necessary for generating an encryption key, a program for generating PSK, device information (for example, MAC address, usable Channel) and other information related to control. The seed value necessary for generating the encryption key may be a unique value (for example, a MAC address) that is different for each image relay device, or may be a dynamic value such as the current time. In particular, if the seed value is a dynamic value, a pre-shared key PSK (Pre-shared key) generated by an encryption key generation unit 36, which will be described in detail later, is different for each image relay device. This contributes to further security improvement of wireless communication performed between the communication terminal and the image relay device. The storage unit 33 is realized by the ROM 21, the RAM 22, the storage device 23, and the like.

  The determination unit 34 determines whether the direct wireless connection request received by the wired communication unit 31 is a request addressed to itself. Specifically, the MAC address of the image relay device requested for connection by the communication terminal T1 included in the direct wireless connection request is extracted and compared with the MAC address of itself (image relay device N1) acquired from the storage unit 33. Then, the communication control unit 32 is notified of the result. The determination unit 34 is realized by the CPU 20, the ROM 21, the RAM 22, and the like.

  The generation unit 35 receives the MAC address of the image relay apparatus itself stored in the storage unit 33, the seed value necessary for generating the encryption key, and the time when the direct wireless connection request is received from the communication terminal T1 (hereinafter, connection request reception). A dedicated SSID is generated based on the time). The generation unit 35 includes an information acquisition unit 351, a random number generation unit 352, and an identifier information generation unit 353. The generation unit 35 is realized by the CPU 20, the ROM 21, the RAM 22, and the like.

  The information acquisition unit 351 acquires the MAC address of the image relay apparatus itself stored in the storage unit 33, the seed value necessary for generating the encryption key, and the connection request reception time. The information acquisition unit 351 is realized by the CPU 20, the ROM 21, the RAM 22, and the like.

  The random number generation unit 352 generates a pseudo-random value based on the seed value, and encrypts the connection request reception time using the pseudo-random value and the connection request reception time using a specific function. Further, the MAC address may be further encrypted with a specific function using a pseudo random number value. The specific function is, for example, a hash function with high irreversibility. The random number generation unit 352 notifies the identifier generation unit 353 of the reception time and MAC address of the encrypted direct wireless connection request or the encrypted MAC address. The random number generation unit 352 is realized by the CPU 20, the ROM 21, the RAM 22, and the like.

  The identifier information generating unit 353 generates a dedicated SSID by associating the MAC address or the encrypted MAC address with the reception time of the encrypted direct wireless connection request. For example, it may be generated by connecting the MAC address and the encrypted connection request reception time with a specific symbol (such as a hyphen). Specifically, the dedicated SSID is represented by “MAC address” − “reception time of encrypted direct wireless connection request” = 84253F012345−C98FF68B135E.

  The identifier information generation unit 353 notifies the transmission unit 322 that the dedicated SSID and the seed value are to be transmitted to the communication terminal T1 via the wired communication unit 31. The identifier information generation unit 353 is realized by the CPU 20, the ROM 21, the RAM 22, and the like.

  The encryption key generation unit 36 generates a pre-common key PSK that is necessary for authentication processing between devices that is performed to enable wireless communication. The PSK is generated based on the dedicated SSID and seed value generated by the generation unit 35 by a program stored in the storage unit 33 in advance. When encrypting wireless communication, it is necessary to exchange and share the encryption key by another means in advance, and PSK is necessary for authentication processing as the first common key of the communication terminal and the image relay device It will be. The encryption key generation unit 36 is realized by the CPU 20, the ROM 21, the RAM 22, and the like.

  FIG. 4 is a functional block diagram of the communication terminal T1 according to the embodiment of the present invention.

  The communication terminal T1 illustrated in FIG. 4 includes a wireless communication unit 30, an instruction unit 40, a communication control unit 41, a storage unit 42, an encryption key generation unit 36, and the like. Note that the wireless communication unit 30 and the encryption key generation unit 36 have the same functions as those provided in the image relay apparatus already described in detail with reference to FIG.

  The instruction unit 40 receives a connection instruction from the application (image display connection tool) stored in the storage unit 42 to an image relay apparatus (hereinafter referred to as a connection request destination) that the user wants to connect. In addition, the communication control unit 41 is notified that a connection request is made toward the connection request destination on the network. The instruction unit 40 is realized by the CPU 20, the ROM 21, the RAM 22, the storage device 23, and the like.

  The communication control unit 41 notifies the wireless communication unit 30 of a search packet in order to search for an image relay device on the network. Further, the communication control unit 41 determines whether or not the response from each image relay apparatus on the network to the search packet is a response from the direct wireless connection request destination. A dedicated SSID request is transmitted to the connection request destination (that is, the image relay apparatus N1) via the wireless communication unit 30 and the relay apparatus A1. The communication control unit 41 is realized by the CPU 20, the ROM 21, the RAM 22, and the like.

  The storage unit 42 includes an SSID used in the relay system, a dedicated SSID acquired from the image relay device, a program for generating a PSK, an image display connection tool, device information (for example, a MAC address, usable channels, etc.), and other controls. Stores information about The storage unit 42 is realized by the ROM 21, the RAM 22, the storage device 23, and the like.

  FIG. 5 shows that the image relay apparatus N1 directly communicates with the communication terminal T1 from the direct wireless connection request of the communication terminal T1 in order to perform wireless communication between the image relay apparatus N1 and the communication terminal T1 according to the embodiment of the present invention. A series of operation flows up to the creation of the pre-common key PSK that is necessary in the authentication process for wireless communication will be described below in order.

  In step S501, the wired communication unit 31 of the image relay device N1 determines whether a direct wireless connection request is received from the communication terminal T1 via the relay device A1. If received, the process proceeds to step S502 (Yes in step S501). If not received, step S501 is repeated to wait for a direct wireless connection request from the communication terminal T1 (No in step S501). The direct wireless connection request is a request transmitted by broadcast communication to each image relay apparatus in the wired network through the wired network N1.

  In step S502, the determination unit 34 of the image relay apparatus N1 determines whether the direct wireless connection request received by the wired communication unit 31 is a request addressed to itself. If the request is for itself, the process proceeds to step S503 (Yes in step S502). If it is not a request addressed to itself, the direct wireless connection request is discarded and no response is made, and step S501 is repeated to wait for a direct wireless connection request from communication terminal T1 (No in step S502). In the image relay apparatus N1 according to the embodiment of the present invention, the direct wireless connection request is discarded and no response is made, but a response may be returned to the communication terminal T1 via the relay apparatus A1. In this way, the communication terminal T1 can acquire the device information of each image relay device in the wired network transmitted by broadcast communication, and the communication terminal T1 has high communication quality and efficiency based on the information. Communication can be performed with each image relay apparatus. The device information is, for example, the communication load status of the image relay device or the communication status of a locally connected device.

  In step S503, the communication control unit 32 of the image relay apparatus N1 receives a notification that the direct wireless connection request is a request addressed to itself by the determination of the determination unit 34 (Yes in step S502), and transmits the transmission unit 322. To the wireless communication terminal T1 through the relay device A1.

  In step S504, the wired communication unit 31 determines whether or not the communication terminal T1 has received a request for a dedicated SSID for connection with itself (the image relay device N1). When the request is received, the process proceeds to step S505 (Yes in step S504). If the request has not been received, step S504 is repeated, and a request for a dedicated SSID is awaited (No in step S504).

  In step S505, the generation unit 35 generates a dedicated SSID from the storage unit 33 based on the MAC address of the image relay apparatus itself, a seed value necessary for generating the encryption key, and the like. More specifically, the information acquisition unit 351 acquires the MAC address, the seed value, and the connection request reception time of the image relay apparatus N1 from the storage unit 33. Next, the random number generation unit 352 generates a pseudo random number value based on the seed value, and encrypts it with a specific function using the pseudo random number value and the reception time of the direct connection request. The identifier information generation unit 353 generates (1) a dedicated SSID by associating the MAC address with the reception time of the encrypted direct connection request. Alternatively, (2) the dedicated SSID may be generated by further encrypting the MAC address using a specific function with the pseudo-random value generated by the random number generation unit 351.

  Specifically, for example, the MAC address of the image relay apparatus N1 is “84: 25: 3F: 01: 23: 45”, and the request reception time for direct connection is “2014101010101” (January 1, 2016, 1 o'clock) 1 minute 1 second). If the reception time of the direct connection request is encrypted with a pseudo-random value (using a hash function or the like) and becomes the code “C98FF68B135E”, the dedicated SSID of (1) is “84253F012345”-“C98FF68B135E”. Further, if the dedicated SSID of (2) above further encrypts the MAC address “84253F012345” of the image relay apparatus N1 with a pseudo random number value (using a hash function or the like) and becomes “1289ABEF3456”, the above (2) The dedicated SSID is “1289ABEF3456”-“C98FF68B135E”. In this way, the dedicated SSID (2) encrypts the MAC address of the image relay apparatus to which the communication terminal is connected, so that the image relay apparatus N1 is malicious compared to the dedicated SSID (1). Since it is possible to prevent a connection destination from being specified by acquiring a MAC address from a certain terminal, it is possible to further improve security.

  In step S506, the transmission unit 322 collectively transmits the dedicated SSID and the seed value generated by the generation unit 35 to the communication terminal T1 via the wired communication unit 31 and the relay device A1 through the wired network L1.

  In step S507, the encryption key generation unit 36 generates a pre-common key PSK. The PSK is generated based on the dedicated SSID and seed value generated by the generation unit 35 by a program stored in the storage unit 33 in advance. The program is stored in the storage unit 33 of the image relay apparatus N1. In this way, since the seed value of the image relay apparatus N1 and the seed value of the communication terminal T1 acquired in step S405 are the same, the PSK can be created with the same generation method (program), and wireless The information necessary for the authentication process for enabling communication matches. Then, the image relay device N1 and the communication terminal T1 succeed in mutual connection processing and authentication processing based on the dedicated SSID and PSK, and wireless communication between both devices becomes possible.

  Next, FIG. 6 shows a state in which the communication terminal T1 directly requests the image relay apparatus N1 for wireless connection in order to perform direct wireless communication between the image relay apparatus N1 and the communication terminal T1 according to the embodiment of the present invention. A series of operation flows up to the creation of the pre-common key PSK that is necessary in the authentication process for directly performing wireless communication with the image relay apparatus N1 will be described below in order.

  In step S600, the instruction unit 40 determines whether or not the user has received an instruction to connect to an image relay apparatus (direct wireless connection request destination) that the user wants to connect to. This connection instruction is performed using the image display connection tool of the communication terminal. If an instruction is received, the process proceeds to step S601 (Yes in step S600). If no instruction has been received, step S600 is repeated to wait for a user instruction (No in step S600).

  In step S601, the wireless communication unit 30 of the communication terminal T1 determines whether or not wireless communication with the relay device A1 is possible. If communication is possible, the process proceeds to step S602 (Yes in step S601). If communication is not possible, step S601 is repeated until wireless communication with relay apparatus A1 becomes possible (No in step S601).

  In step S602, the instruction unit 40 notifies the communication control unit 41 that a search is performed toward a connection request destination on the network (direct wireless connection request is performed). This step is an important step for the communication terminal T1 to perform direct wireless communication with the image relay device N1. Upon receiving the notification from the instruction unit 40, the communication control unit 41 notifies the wireless communication unit 30 of a search packet for searching for the image relay device N1 on the network via the relay device A1. Specifically, the communication control unit 41 includes the MAC address or IP address of the desired image relay device in the search packet and notifies the wireless communication unit 30 and the wireless communication unit 30 enters the network via the relay device A1. Perform broadcast transmission.

  In step S603, the communication control unit 41 determines whether the response from each image relay device on the network to the search packet received via the wireless communication unit 30 via the relay device A1 is a response from the connection request destination. Judging. If it is a response from the connection request destination, the process proceeds to step S604 (Yes in step S603). If it is not a response from the connection request destination, step S603 is repeated to wait for a response from the connection request destination (No in step S603). Note that there is not always a response from each image relay apparatus on the network. The reason is that the specification is such that the image relay device does not respond to a search packet that is not a connection request addressed to itself, or the image relay device cannot respond physically (power failure, failure, network failure, etc.). .

  In step S604, the communication control unit 41 transmits a request for a dedicated SSID to the connection request destination via the wireless communication unit 30 and the relay device A1.

  In step S605, the communication control unit 41 determines whether a dedicated SSID and a seed value are received from the connection request destination via the wireless communication unit 30 via the relay device A1. If received, the dedicated SSID and seed value are stored in the storage unit 42, and the process proceeds to step S606 (Yes in step S606). If not received, step S605 is repeated to wait for reception of the dedicated SSID and seed value from the connection request destination (No in step S606).

  In step S606, the encryption key generation unit 36 generates a pre-shared key PSK (Pre-shared key) that is necessary for the authentication process between devices performed to enable wireless communication. The PSK is generated based on a dedicated SSID and a seed value by a program stored in the storage unit 42 in advance. The program is stored in the storage unit 42 of the communication terminal T1.

  Next, FIG. 7 shows the processing flow according to the embodiment of the present invention described with reference to FIGS. 5 and 6 (since the communication terminal T1 makes a direct wireless connection request to the image relay apparatus N1, the image relay apparatus N1 is directly connected. The flow until wireless communication is performed) is represented as a sequence diagram of the entire system. Below, it demonstrates in order, referring each step corresponding to FIG. 5 and FIG.

  In sequence S700, the communication terminal T1 is wirelessly connected to the relay device A1 and performs communication (step S601 in FIG. 6).

  In sequence S701, the communication terminal T1 transmits a search packet to the relay device A1 in order to directly search for a wireless connection request destination among a plurality of image relay devices existing on the network (step S602 in FIG. 6).

  In sequence S702, the relay device A1 relays a packet for searching for a connection request destination from the communication terminal 1 to a plurality of image relay devices existing in the network, and transmits the packet by broadcast communication through the wired network L1 ( Step S602 in FIG. 6).

  In sequence S703, the image relay apparatus (not subject) that has received the search packet is not a connection request addressed to itself, and therefore does not return a response to the search packet including that fact. (Or a response may be returned as described above.) (No in step S502 in FIG. 5, No in step S602 in FIG. 6).

  In sequence S704, the image relay apparatus that is the target of the connection request that has received the search packet returns a response to the search packet because it is a connection request addressed to itself (step S503 in FIG. 5, Yes in step S602 in FIG. 6). ).

  In sequence S705, the communication terminal T1 requests a dedicated SSID from the image relay device N1 that is the connection request destination via the wired network L1 via the relay device A1 (step S604 in FIG. 6).

  In sequence S706, the connection request destination image relay apparatus N1 creates a dedicated SSID (step S505 in FIG. 5).

  In sequence S707, the connection request destination image relay apparatus N1 collects the created dedicated SSID and encryption key (seed value), and transmits response data to the dedicated SSID request to the communication terminal T1 via the relay apparatus A1. (Step S506 in FIG. 5).

  In sequence S708, a pre-common key PSK necessary for authentication processing between devices, which is performed to enable wireless communication, is generated in each of the connection request destination image relay device and communication terminal T1 (FIG. 5). Step S507, Step S606 of FIG. 6).

  In sequence S709, the communication terminal T1 makes a connection request to the connection request destination image relay apparatus using the dedicated SSID.

  In sequence S710, the connection request destination image relay apparatus receives and responds to the connection request from the communication terminal T1, and thereafter, after successful connection processing (association), authentication processing, and the like for wireless communication, the communication terminal Direct wireless communication is started between T1 and the connection request destination image relay apparatus.

  Here, the background of the present invention will be described again. For example, the user may want to control the large display device D1 that is wirelessly connected to the image relay device N1 in the classroom A from the communication terminal T1 to be used and is locally connected. At this time, if the image relay device N2 of the classroom B has a higher RSSI than the image relay device N1 of the classroom A, the communication terminal T1 normally connects the image relay device N2 preferentially, and as a result, the classroom B The image relay device N2 controls the large display device D1 via the image relay device N1, and the large display device D1 cannot be controlled by wireless connection to the image relay device N1 in the classroom A intended by the user.

  On the other hand, according to the embodiment of the present invention, the processing procedure of the present invention shown in FIGS. 5, 6, and 7 described above is followed. That is, the user selects a specific image relay apparatus (connection request destination) to be connected on the communication terminal to be used, and requests a dedicated SSID for direct wireless connection. Upon receiving the request, the connection request destination image relay apparatus dynamically generates a dedicated SSID, and transmits the dedicated SSID and the encryption key stored in the connection request destination image relay apparatus to the communication terminal T1. In this way, information (SSID, PSK, etc.) for enabling wireless communication is exclusively used between the communication terminal T1 and the image relay device N1, and as a result, a plurality of image relay devices. Are operated with the same SSID (general-purpose SSID), the user can directly perform wireless communication with the image relay apparatus of the connection request destination.

(Other examples)
FIG. 8 is an overall view of a relay system according to another embodiment of the present invention.

  As shown in FIG. 8, the relay system 110 according to another embodiment of the present invention further includes a staff room in the distance from the relay system shown in FIG. A relay device A2 is installed in the staff room, and a relay device A3 is installed in the hallway. The relay device A2 and the relay device A3 are connected to the image relay devices N1 and N2 through a wired network L2.

  In the example of the relay system 110 according to another embodiment of the present invention, first, a large display in which a user (teacher) is connected to the image relay device N1 using the image display connection tool of the communication terminal T1 in the staff room. When the device D1 is selected, the large-sized display device D1 that is connected to the image relay device N1 via a wired network L2 via the relay device A2 by wireless communication (wireless communication path W2) and is locally connected thereto is controlled. Next, when the user leaves the staff room and moves to a range (corridor) where wireless communication with the relay device A2 cannot be performed and moves to a range where wireless communication with the relay device A3 can be performed, the user roams to the relay device A3 (wireless communication path W3). The large-scale display device D1 is controlled by wired connection with the image relay device N1 through the wired network L2.

  Here, when the communication terminal T1 specifies the image relay device (N1) that controls the desired display device, the communication terminal T1 directly connects to the image relay device N1 and performs wireless communication via the relay device A2 and the relay device A3. In this embodiment, the communication terminal T1 periodically issues a direct wireless connection request for the image relay device N1 using the image display connection tool. The response of the image relay apparatus N1 in response to this is as described above, but waits until the wireless key can be directly communicated when the encryption key necessary for authentication is created by both (the communication terminal T1 and the image relay apparatus N1). Will be. Then, if the communication terminal T1 can directly connect to the image relay apparatus N1 and perform wireless communication, an authentication process can be performed. From the connection path to the relay apparatus A2 and the relay apparatus 3 that have been wirelessly connected, The direct image relay device N1 can smoothly switch to a route for controlling the large display device D1. That is, the user of the communication terminal T1 controls the current large display device D1 from the relay device A3 (communication using a general-purpose SSID) without being aware of the operations from step S602 to step S606 in FIG. Therefore, it is automatically switched to the image relay apparatus N1 (communication using a dedicated SSID) in use.

  As described above, by using the image relay device of the present invention, even when the image relay device to be connected to the communication terminal cannot perform wireless communication, a different route (connection via a relay device or a wired network) can be used. ) To maintain the connection and communicate. After that, if the communication terminal can directly perform wireless communication with the image relay apparatus to be connected, it is possible to directly connect to the image relay apparatus desired by the user.

  The relay device described so far as the embodiment of the present invention is an image relay device that receives display image data from a communication terminal over a network and displays it on a locally connected display device. As described at the beginning, such a device has a USB over IP function, and controls not only the display device but also a USB device over a network. Therefore, for example, when the USB printer is used from the communication terminal T1 via the device by the connection tool, the present invention is applied in order to prevent wireless connection to a different device. Are directly connected to each other with a dedicated SSID. Considering such development, the present invention can be applied not only to image relay apparatuses but also to peripheral device relay apparatuses.

  Furthermore, although this peripheral device relay apparatus according to the embodiment of the present invention has been described as an apparatus having a function capable of controlling a locally connected apparatus over a network, a relay apparatus having no such function ( The present invention is also applicable to a so-called wireless access point such as the relay device A1 according to the embodiment of the present invention.

  For example, in an environment where a network is constructed by a plurality of relay devices using the same SSID, when a monitor device that constantly monitors the wireless environment in the network (survey) is installed, the monitor device Enable the relay device to acquire information. Here, if the present invention is applied, the communication terminal of the user has a small wireless communication load (for example, there are few devices connected to the relay device, and an empty channel that does not overlap with other relay devices can be secured). Direct communication with a specific relay device is possible.

  In other words, the user normally performs wireless communication using the SSID set at the time of network construction, but the user's usage conditions (for example, a large amount of data communication, communication in a short time, etc.) By referring to the information acquired from the monitor device by the user and selecting a wireless connection with the specific relay device, wireless communication with the specific relay device can be performed without taking the trouble of newly setting the SSID.

  This is useful in a case where a wireless network in which a plurality of wireless communication apparatuses are configured with the same SSID is used for wireless connection and communication only with a specific peripheral device relay apparatus desired by the user.

100, 110 Relay system N1, N2 Image relay device T1 Communication terminals A1, A2, A3 Relay device D1, D2 Large display device C1, C2 Wired cable L1, L2 Wired network W1, W2, W3 Wireless communication path 20 CPU
21 ROM
22 RAM
23 Storage device 24 External output_I / F
25 WNIC
26 NIC
27 Internal bus 30 Wireless communication unit 31 Wired communication unit 32, 41 Communication control unit 321 Reception unit 322 Transmission unit 33, 42 Storage unit 34 Determination unit 35 Generation unit 351 Information acquisition unit 352 Random number generation unit 353 Identifier information generation unit 36 Encryption key Generation unit 40 instruction unit

Claims (4)

A peripheral device relay device in an image display system in which a plurality of peripheral device relay devices that are network-connected to a communication terminal and relay a communication between the peripheral device connected to the communication terminal and the communication terminal are connected via a wired network. There,
A wired communication unit that determines whether a direct wireless connection request from the communication terminal is received via the wired network; and
A receiving unit for acquiring a time at which the direct wireless connection request is received;
A storage unit for storing a unique identifier for identifying itself and a seed value;
A determination unit that determines whether or not the request is for the device itself based on the unique identifier extracted from the direct wireless connection request;
Based on the unique identifier, the seed value, and the time when the direct wireless connection request is received, a generating unit that generates a network identifier;
A peripheral device relay apparatus comprising: a transmission unit that transmits the network identifier and the seed value as response data of the direct wireless connection request. The generator is
Based on the seed value, a random number generator that generates a pseudo-random number value;
Identifier information generation for generating a network identifier that associates the unique identifier or the unique identifier encrypted by the random number generator with the time when the direct wireless connection request encrypted by the random number generator is received The peripheral device relay device according to claim 1. A communication terminal;
An image relay device connected to the communication terminal via a network and displaying image data transmitted from the communication terminal on a display device connected to the communication terminal, each of which is a plurality of image relay devices connected via a wired network; An image display system including
When the communication terminal identifies an image relay device that controls a desired display device among a plurality of image relay devices, the communication terminal periodically transmits a direct wireless connection request to the image relay device,
The image relay device includes:
A wired communication unit that determines whether a direct wireless connection request from the communication terminal is received via the wired network; and
A receiving unit for acquiring a time at which the direct wireless connection request is received;
A storage unit for storing a unique identifier for identifying itself and a seed value;
A determination unit that determines whether or not the request is for the device itself based on the unique identifier extracted from the direct wireless connection request;
Based on the unique identifier, the seed value, and the time when the direct wireless connection request is received, a generating unit that generates a network identifier;
A transmission unit for transmitting the network identifier and the seed value;
Upon receiving the direct wireless connection request from the communication terminal, an image display system responsive to said seed value and said network identifier to the communication terminal. A communication terminal;
An image relay device connected to the communication terminal via a network and displaying image data transmitted from the communication terminal on a display device connected to the communication terminal, each of which is a plurality of image relay devices connected via a wired network; ,including
An image display system ,
When the communication terminal identifies an image relay device that controls a desired display device among a plurality of image relay devices, the communication terminal periodically transmits a direct wireless connection request to the image relay device,
The image relay device
A wired communication unit that determines whether a direct wireless connection request from the communication terminal is received via the wired network; and
A receiving unit for acquiring a time at which the direct wireless connection request is received;
A storage unit for storing a unique identifier for identifying itself and a seed value;
A determination unit that determines whether or not the request is for the device itself based on the unique identifier extracted from the direct wireless connection request;
Based on the seed value, a random number generator that generates a pseudo-random number value;
Identifier information generation for generating a network identifier that associates the unique identifier or the unique identifier encrypted by the random number generator with the time when the direct wireless connection request encrypted by the random number generator is received And
A transmission unit for transmitting the network identifier and the seed value;
Upon receiving the direct wireless connection request from the communication terminal, an image display system responsive to said seed value and said network identifier to the communication terminal.