JP2005341094A - Data transmission system, data transmission device, distribution device, and data transmission method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data transmission system for achieving safe radio data communication, and to provide a data transmission device in the data transmission system, a distribution device, and a data transmission method. <P>SOLUTION: An electric light line communication section 106 in the data transmission device 100 acquires an equipment ID of other data transmission devices 100 in a closed network utilizing an electric light line. An authentication section 114 identifies other data transmission devices 100 for allowing for radio data communication, based on the equipment ID of other data transmission devices 100 acquired by the electric light line communication section 106. A radio section 104 performs the radio data communication with other data transmission devices 100 allowed by the electric light line communication section 106. The highly confidential closed network is utilized to perform radio data communication with the permitted data transmission device 100, thus increasing safety in the radio data communication. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a data transmission system that performs wireless data communication in a limited environment such as a home or office, a data transmission device and a power distribution device in the data transmission system, and a data transmission method.

  2. Description of the Related Art In recent years, home networks that allow data transmission and reception by connecting a plurality of home appliances and household equipment in a home have become widespread. As an example of a home network, a personal computer or a printer is connected to each other without using a wired cable, and wireless communication (hereinafter simply referred to as “wireless data communication”) such as radio waves or light is performed. Network). According to this wireless LAN, a cableless and smart communication environment can be realized.

When wireless data communication is performed, the system side needs to accurately manage what devices are connected. For example, Patent Document 1 discloses a technique in which a system side of a home network uniquely determines a device identification code and assigns the device identification code to each device via wireless communication.
JP 2003-8576 A

  Certainly, according to Patent Document 1, the system side can recognize each device by assigning a unique identification code to each device via wireless, but is aware of the safety of wireless data communication. It is not a thing, but a new consideration about it is necessary.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a data transmission system that realizes highly secure wireless data communication, a data transmission device and a power distribution device in the data transmission system, and a data transmission method. On offer.

  One embodiment of the present invention relates to a data transmission apparatus. This device uses a power line communication unit for acquiring device information of another data transmission device in a closed network using a power line, and wireless data communication based on the acquired device information of the other data transmission device. An authentication unit that specifies another data transmission device that permits the wireless communication, and a wireless unit that performs wireless data communication with the other data transmission device specified by the authentication unit. According to this aspect, since the wireless data communication is performed with the data transmission apparatus permitted based on the device information in the closed network with high confidentiality, the safety of the wireless data communication can be improved.

  The apparatus further includes a holding unit that holds device information of another data transmission device, and the authentication unit permits wireless data communication based on the device information of the other data transmission device held by the holding unit. The data transmission device may be specified.

  Another aspect of the present invention relates to a data transmission system. This system includes a plurality of data transmission devices and a power distribution device that collects a plurality of power lines from the plurality of data transmission devices, and a data transmission system that forms a closed network with the power distribution devices and the plurality of power lines. The power distribution device is electrically connected to an external power line, and includes a filter that blocks leakage of device information of the data transmission device to the external power line. According to this aspect, since leakage of device information to the outside can be suppressed, the confidentiality of the closed network can be improved.

  Yet another embodiment of the present invention relates to a power distribution device. This device is a power distribution device that collects a plurality of power lines to form a closed network and electrically connects the closed network and an external power line, and is a device of equipment connected to the closed network A filter is provided to block leakage of information to the outside. According to this aspect, since leakage of device information to the outside can be suppressed, the confidentiality of the closed network can be improved.

  Yet another embodiment of the present invention relates to a data transmission method. In this method, wireless data communication is permitted based on a step of acquiring device information of another data transmission device in a closed network using a power line, and the acquired device information of the other data transmission device. A step of identifying another data transmission device and a step of performing wireless data communication with the identified other data transmission device.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, highly secure wireless data communication can be realized.

Embodiment 1
FIG. 1 shows a configuration of a data transmission apparatus 100 according to the present embodiment. This apparatus performs wireless transmission / reception processing of information signals such as AV (Audio Visual) data and text data, that is, wireless data communication, with other data transmission apparatuses 100. AV data is data including image data and audio data. The data transmission apparatus 100 includes an AV input / output unit 102, a wireless unit 104, a power line communication unit 106, a device ID holding unit 108, an infrared light receiving unit 110, an infrared transmission unit 112, an authentication unit 114, an encryption unit, Unit 116, decoding unit 118, and control unit 150.

  The AV input / output unit 102 exchanges AV data with the AV device 200 outside the data transmission apparatus 100. The AV device 200 is provided for each data transmission device 100. The AV device 200 refers to, for example, a television receiver, a video tape recorder, or a laser disc player. The target of AV data exchange is not limited to the AV device 200 described above, but may be any device that can recognize AV data, such as a personal computer or a game device.

  The wireless unit 104 searches for another data transmission apparatus 100 capable of wireless data communication by transmitting a search signal wirelessly. The first search process is performed when the power plug 12 of the data transmission apparatus 100 is inserted into an outlet (not shown), that is, when power is first supplied to the data transmission apparatus 100. The subsequent search processing is repeatedly executed at predetermined intervals while power is supplied to the data transmission apparatus 100. By repeatedly performing the search process, it is possible to confirm whether or not the other data transmission apparatus 100 is still in a state where wireless data communication is possible. After the search process, the wireless unit 104 performs wireless data communication with another data transmission apparatus that is permitted wireless data communication by the authentication unit 114 described later, using the antenna 10 that the wireless unit 104 has.

  The power line communication unit 106 performs data communication (hereinafter referred to simply as “power line network”) in a closed network (hereinafter simply referred to as “power line network”) using the power line while the power plug 12 of the data transmission apparatus 100 is plugged into the outlet. Simply referred to as “power line data communication”). During the power line data communication, the power line communication unit 106 sends a device ID, which is device information unique to the data transmission device 100, to the other data transmission device 100, and sends the device ID of the other data transmission device 100 to the other. From the data transmission apparatus 100. The power line communication unit 106 may exchange device information unique to the AV device 200 corresponding to the data transmission device 100, such as a model number or a serial number. In any case, the device information is not duplicated between other devices and devices. The power line communication unit 106 holds the device ID of the other data transmission apparatus 100 acquired in the power line network in the device ID holding unit 108.

  The infrared light receiving unit 110 receives an instruction regarding the operation of the AV data from the user by the remote controller 16 and transmits the instruction to the control unit 150 described later. The infrared transmission unit 112 transmits an instruction from the user received by the infrared light receiving unit 110 to the AV device 200 by infrared rays via the infrared light emitting module 18. If the instruction is related to the operation of the AV data of the other AV device 200, the data transmission device 100 instructs the wireless unit 104 of the other data transmission device 100 corresponding to the other AV device 200 via the wireless unit 104. Forward.

  The authentication unit 114 identifies another data transmission device that permits wireless data communication based on the device ID of the other data transmission device acquired by the power line communication unit 106 in the power line network. Specifically, the authentication unit 114 includes, in the device ID group of the other data transmission device 100 held in the device ID holding unit 108, the other data transmission device 100 acquired at the time of power line data communication. Depending on whether or not the same device ID as the device ID exists, another data transmission device 100 that permits wireless data communication is specified. The authentication unit 114 may operate as a specifying unit that specifies another data transmission device 100 that permits wireless data communication.

  Due to the nature of wireless data communication, there is a possibility that radio waves may be transmitted to the data transmission device 100 that does not exist in the same power line network, for example, the data transmission device 100 of a neighbor, and there is a high risk of impersonation by a third party. However, the safety of wireless data communication may not be high. Therefore, it is meaningful to specify a partner who permits wireless data communication by using a closed power line network with high confidentiality and perform wireless data communication with the specified partner.

  The device ID is uniquely present in the power line network and rarely leaks outside the closed power line network with high confidentiality. The data transmission apparatus 100 can suppress wireless data communication with a data transmission apparatus that does not exist in the same power line network by specifying a partner to which wireless data communication is permitted using such an apparatus ID. The safety of wireless data communication can be improved.

  As described above, when the data transmission apparatus 100 exchanges the device ID, since the closed power line network with high confidentiality is used, the device ID rarely leaks outside the power line network. Therefore, the trouble of encrypting the device ID itself can be saved, and the hardware scale and software scale for the encryption processing can be reduced.

  When identifying a partner to whom wireless data communication is permitted, the data transmission device 100 only needs to compare the acquired device ID of the other data transmission device 100 with the device ID group stored in the device ID holding unit 108. is there. Thereby, the safety | security of wireless data communication can be improved with a comparatively simple method.

  The encryption unit 116 generates one common key for the device ID of its own data transmission apparatus 100 using a predetermined algorithm, for example, a hash function. After generating the common key, the encryption unit 116 encrypts the AV data using the common key. The encryption unit 116 may generate one common key for a device ID of a distribution board (not shown in FIG. 1) in the power line network. The encryption unit 116 may include a random number generation unit (not shown) in the inside thereof, connect the random number generated by the random number generation unit to the device ID, and apply a predetermined algorithm to generate one common key. The random number may be generated by a distribution board. The random number may be the current date. By encrypting AV data, eavesdropping from a third party can be suppressed, and the safety of wireless data communication can be improved.

  The decrypting unit 118 decrypts the AV data encrypted with the common key, using the common key generated based on the device ID of the own data transmission apparatus 100 used at the time of encryption.

  The control unit 150 controls various functions of the AV input / output unit 102, the wireless unit 104, the power line communication unit 106, the infrared light receiving unit 110, the infrared transmission unit 112, the authentication unit 114, the encryption unit 116, and the decryption unit 118. The control unit 150 transfers AV data acquired by the AV input / output unit 102 to the wireless unit 104, and transfers AV data received by the wireless unit 104 to the AV input / output unit 102. Further, the control unit 150 controls the encryption unit 116 to encrypt the AV data acquired by the AV input / output unit 102 or decrypts the encrypted AV data received by the wireless unit 104. The unit 118 is controlled.

  FIG. 2 shows a configuration of the control unit 150 according to the present embodiment. The control unit 150 includes an input / output control unit 152, a central control unit 154, a wireless control unit 156, a switching unit 158, and a power line communication control unit 160.

  The input / output control unit 152 acquires the AV data of the AV device 200 corresponding to its own data transmission device 100 when there is an instruction to transmit the AV data to the other data transmission device 100 from the central control unit 154 described later. Thus, the AV input / output unit 102 is controlled.

  The wireless control unit 156 receives the AV data of its own data transmission device 100 acquired by the AV input / output unit 102 when an instruction to transmit AV data to another data transmission device 100 is received from the central control unit 154 described later. The wireless unit 104 is controlled so as to be transmitted to the other data transmission apparatus 100 wirelessly. Further, when there is an instruction from the user regarding the operation of AV data of another AV device 200 via the remote controller 16, the wireless control unit 156 wirelessly transmits the instruction from the user received by the infrared light receiving unit 110. The wireless unit 104 is controlled to transfer to another data transmission apparatus 100.

  The power line communication control unit 160 controls the power line communication unit 106 to transmit the device ID of its own data transmission device 100 to other data transmission devices 100 in the power line network during power line data communication. .

  The switching unit 158 switches the output destination of the control signal to one of the wireless control unit 156 and the power line communication control unit 160 based on an instruction from the central control unit 154 described later. That is, when the AV data is exchanged by wireless data communication, the output destination of the control signal is switched to the wireless control unit 156, and when the device ID is exchanged by power line data communication, the output destination of the control signal is the power line. The communication control unit 160 is switched. The central control unit 154 controls various functions of the input / output control unit 152, the wireless control unit 156, the switching unit 158, and the power line communication control unit 160.

  3A shows the switching state of the switch SW in the switching unit 158 at the first timing, and FIG. 3B shows the switching state of the switch SW in the switching unit 158 at the second timing. Show. The first timing indicates a case where AV data is exchanged by wireless data communication, and the second timing indicates a case where a device ID is exchanged by power line data communication. As illustrated, at the first timing, the output destination of the control signal from the central control unit 154 is switched to the radio control unit 156 by the switch SW, so that the radio control unit 156 can be controlled. Similarly, at the second timing, the power line communication control unit 160 can be controlled.

  FIG. 4 schematically shows an example of the data transmission system 40. The data transmission system 40 includes a first power line 22a to a third power line 22c, a first data transmission apparatus 100a to a third data transmission apparatus 100c, and a distribution board 20. In the first floor portion of the house 30, the distribution board 20, the first data transmission device 100a, and the first AV device 200a, for example, a video tape recorder, and on the second floor portion, the second data transmission device 100b, and the second AV device. 200b, for example a television receiver, is provided on the third floor with a third data transmission device 100c and a third AV device 200c, for example a television receiver. The first power plug 12a to the third power plug 12c of the first data transmission device 100a to the third data transmission device 100c are respectively inserted into the first outlet 14a to the third outlet 14c.

  The distribution board 20 collects the first power line 22a to the third power line 22c from the first data transmission apparatus 100a to the third data transmission apparatus 100c, respectively, and electrically connects them to the external power line 24. Connecting. The distribution board 20 constitutes a closed power line network by assembling the first power line 22a to the third power line 22c. Here, the first data transmission device 100a to the third data transmission device 100c and the first AV equipment 200a to the third AV equipment 200c may be referred to as a closed power line network. The distribution board 20 includes a filter that blocks leakage of the device ID of each of the first data transmission device 100a to the third data transmission device 100c to the external power line 24. As a result, a closed power line network with high confidentiality can be realized, and highly secure wireless data communication can be realized.

  FIG. 5 shows an example of wireless data communication between the first data transmission device 100a and the second data transmission device 100b in FIG. As described above, the first data transmission device 100a and the first AV device 200a are provided in the first floor portion, and the second data transmission device 100b and the second AV device 200b are provided in the second floor portion. In the following, the same components as those in FIG.

  In response to an instruction from the user by the remote controller 16, an instruction regarding the operation of AV data is transferred from the second wireless unit 104b in the second data transmission apparatus 100b to the first wireless unit 104a in the first data transmission apparatus 100a. Based on the instruction, the first control unit 150a performs an AV data reproduction operation on the first AV device 200a connected to the outside of the first data transmission device 100a. The first AV input / output unit 102a acquires AV data reproduced by the first AV device 200a. The first control unit 150a sends AV data to the second radio unit 104b via the first radio unit 104a. The second AV input / output unit 102b outputs the acquired AV data to the second AV device 200b. As a result, AV data reproduced by the first AV device 200a on the first floor can be output to the screen of the second AV device 200b on the second floor.

  FIG. 6 shows a flow of AV data transmission processing according to the present embodiment. The second radio unit 104b of the second data transmission device 100b sends a search signal into the power line network (S10). If the wireless data communication is possible, the first wireless unit 104a of the first data transmission device 100a sends a response signal to the second wireless unit 104b (S12).

  The second power line communication unit 106b of the second data transmission device 100b transmits its own device ID to the first power line communication unit 106a of the first data transmission device 100a in the closed power line network (S14). . When the device ID transmitted from the second power line communication unit 106b is not a new device ID (N in S16), the first authentication unit 114a compares the device ID group stored in the first device ID storage unit 108a with the device ID group. To do. If the same device ID exists, wireless data communication from the second data transmission device 100b is permitted (S20). If the device ID sent from the second power line communication unit 106b is a new ID (Y in S16), the first power line communication unit 106a sets the device ID sent from the second power line communication unit 106b to the first ID. The first authentication unit 114a permits the wireless data communication from the second data transmission device 100b (S20).

  The first power line communication unit 106a of the first data transmission device 100a transmits its device ID to the second power line communication unit 106b of the second data transmission device 100b through the power line network (S22). If the device ID sent from the first power line communication unit 106a is not a new ID (N in S24), the second authentication unit 114b compares it with the device ID group held in the second device ID holding unit 108b. To do. If the same device ID exists in the group, wireless data communication from the first data transmission device 100a is permitted (S28). If the device ID sent from the first power line communication unit 106a is a new ID (Y in S24), the second power line communication unit 106b sets the device ID sent from the first power line communication unit 106a to the first ID. 2 is held in the device ID holding unit 108b (S26), and wireless data communication from the first data transmission device 100a is permitted (S28).

  The second infrared light receiving unit 110b of the second data transmission device 100b receives an AV data transmission instruction from the user via the remote controller 16 (S30). The second wireless unit 104b of the second data transmission device 100b transmits the AV data transmission instruction from the user received by the second infrared light receiving unit 110b to the first wireless unit 104a of the first data transmission device 100a (S32). ). Prior to transmission, the second wireless unit 104b of the second data transmission device 100b may check whether the first data transmission device 100a is still in a state where wireless data communication is possible by a search process.

  The first encryption unit 116a of the first data transmission device 100a encrypts AV data with a common key generated based on its own device ID (S34). The first wireless unit 104a of the first data transmission device 100a transmits the AV data encrypted by the first encryption unit 116a to the second wireless unit 104b of the second data transmission device 100b (S36).

  The second decryption unit 118b of the second data transmission device 100b decrypts the encrypted AV data using the common key generated based on the device ID of the first data transmission device 100a that is the transmission partner ( S38). The second AV input / output unit 102b of the second data transmission device 100b outputs the AV data decoded by the second decoding unit 118b to the second AV device 200b (S40).

Embodiment 2
The second embodiment is different from the first embodiment in that the search process is not performed wirelessly but the search process is performed in the power line network. At this time, the power line communication unit 106 has a search processing function of the wireless unit 104 in FIG.

  The power line communication unit 106 transmits a search signal including the device ID of its own data transmission device 100 during the search process in the power line network. If there is a response signal from another data transmission device 100 within a predetermined time, the power line communication unit 106 holds the device ID of the other data transmission device 100 included in the response signal in the device ID holding unit 108. When there is no response signal from another data transmission device 100 within a certain time, the power line communication unit 106 determines the device ID of the data transmission device 100 having no response from the device ID group held in the device ID holding unit 108. delete. In this way, the security of the search process can be enhanced by performing the search process in the closed power line network with high confidentiality.

  FIG. 7 shows a flow of AV data transmission processing according to the present embodiment. The second power line communication unit 106b of the second data transmission device 100b sends a search signal including the device ID of its own second data transmission device 100b in the power line network (S52).

  When the device ID transmitted from the second power line communication unit 106b is not a new device ID (N in S54), the first authentication unit 114a compares the device ID group stored in the first device ID storage unit 108a with the device ID group. To do. If the same device ID exists in the group, wireless data communication from the second data transmission device 100b is permitted (S58). If the device ID sent from the second power line communication unit 106b is a new ID (Y in S54), the first power line communication unit 106a sets the device ID sent from the second power line communication unit 106b to the first ID. The first authentication unit 114a permits the wireless data communication from the second data transmission device 100b (S58).

  The first power line communication unit 106a of the first data transmission device 100a sends its device ID to the second power line communication unit 106b of the second data transmission device 100b within the power line network (S60). When the second power line communication unit 106b of the second data transmission device 100b does not acquire the device ID within a certain time (N in S62), the second power line communication unit 106b is in the device ID group held in the second device ID holding unit 108b. Is deleted (S64). When the device ID is acquired within a certain time (Y in S62), the above deletion is not performed.

  If the device ID transmitted from the first power line communication unit 106a is not a new ID (N in S66), the second authentication unit 114b compares it with the device ID group stored in the second device ID storage unit 108b. If the same device ID exists in the group, the wireless data communication from the first data transmission device 100a is permitted (S70). If the device ID sent from the first power line communication unit 106a is a new ID (Y in S66), the second power line communication unit 106b sets the device ID sent from the first power line communication unit 106a to the first ID. 2 is held in the device ID holding unit 108b (S68), and wireless data communication from the first data transmission device 100a is permitted (S70).

  The second infrared light receiving unit 110b of the second data transmission device 100b receives an AV data transmission instruction from the user via the remote controller 16 (S72). The second radio unit 104b of the second data transmission device 100b transmits an instruction regarding the operation of AV data from the user received by the second infrared light receiving unit 110b to the first radio unit 104a of the first data transmission device 100a ( S74). Before the transmission, the second power line communication unit 106b of the second data transmission device 100b confirms whether or not the first data transmission device 100a is still capable of wireless data communication by the search process. Good.

  The first encryption unit 116a of the first data transmission device 100a encrypts AV data with a common key generated based on its own device ID (S76). The first wireless unit 104a of the first data transmission device 100a transmits the AV data encrypted by the first encryption unit 116a to the second wireless unit 104b of the second data transmission device 100b (S78).

  The second decryption unit 118b of the second data transmission device 100b decrypts the encrypted AV data using the common key generated based on the device ID of the first data transmission device 100a that is the transmission partner ( S80). The second AV input / output unit 102b of the second data transmission apparatus 100b outputs the AV data decoded by the second decoding unit 118b to the second AV device 200b (S82).

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

1 is a diagram illustrating a configuration of a data transmission device according to a first embodiment. 3 is a diagram illustrating a configuration of a control unit according to Embodiment 1. FIG. FIG. 3A is a diagram illustrating a switching state of the switch in the switching unit at the first timing, and FIG. 3B is a diagram illustrating a switching state of the switch in the switching unit at the second timing. is there. It is a figure which shows an example of a data transmission system typically. It is a figure which shows an example of the radio | wireless data communication between a 1st data transmission apparatus and a 2nd data transmission apparatus. 6 is a diagram illustrating a flow of AV data transmission processing according to Embodiment 1. FIG. FIG. 10 is a diagram illustrating a flow of AV data transmission processing according to the second embodiment.

Explanation of symbols

  20 Power distribution board, 22a-22c 1st power line-3rd power line, 24 External power line, 40 Data transmission system, 100 Data transmission device, 104 Wireless part, 106 Power line communication part, 108 Device ID holding part, 114 Authentication department.

Claims (5)

A power line communication unit that acquires device information of other data transmission devices in a closed network using the power line; and
Based on the acquired device information of the other data transmission device, an authentication unit that identifies another data transmission device that permits wireless data communication;
A wireless unit that performs wireless data communication with another data transmission device identified by the authentication unit;
A data transmission device comprising: A holding unit for holding device information of the other data transmission device;
The said authentication part specifies the other data transmission apparatus which permits the said wireless data communication based on the apparatus information of the other data transmission apparatus hold | maintained at the said holding | maintenance part. Data transmission device. A data transmission system comprising: a plurality of data transmission devices; and a power distribution device that collects a plurality of power lines from the plurality of data transmission devices, wherein the power distribution device and the plurality of power lines form a closed network. There,
The data distribution system, wherein the power distribution device is electrically connected to an external power line, and includes a filter that blocks leakage of device information of the data transmission device to the external power line.   A power distribution device that collects a plurality of lamp lines to form a closed network, and electrically connects the closed network and an external power line, and includes a device information of a device connected to the closed network A power distribution device comprising a filter that blocks leakage to the outside. Obtaining device information of other data transmission devices in a closed network using power lines; and
Identifying another data transmission device that permits wireless data communication based on the acquired device information of the other data transmission device;
Performing wireless data communication with the identified other data transmission device;
A data transmission method characterized by comprising:

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