JP2003037560A - Household lan system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically compose a high security household LAN system. SOLUTION: The household LAN system is composed of plural systems of LAN including an optical LAN. Devices using data necessary to provide secrecy such as PIN(personal identification number) are connected to the optical LAN keeping reliability high and other devices are connected to an economical LAN such as a power-line carrier, etc. For data transmission and reception with the outside when outside communication uses transmission medium other than optical transmission and data transmission and reception of the devices connected to the LAN other than the optical LAN, a control equipment 1 determines necessity of secrecy of the data, uses cryptograph, or issues an alarm to the users.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a home LAN system, and more particularly to a home LAN system capable of preventing information leakage as much as possible.

[0002]

2. Description of the Related Art As a transmission line used in a home LAN system, various types such as optical, wireless, metal cable, and power line carrier can be used. If a home LAN system is configured using multiple types of these transmission lines, for example, only devices that require large-capacity communication are connected by optical transmission lines, and the amount of data such as ON / OFF control data for air conditioners is small. It is possible to reduce the cost of the home LAN system as a whole by differentiating the transmission path to be used according to the communication capacity, such as connecting by the power line carrier system which has a low communication cost but low system cost.

In order to cope with the change or expansion of the equipment connected to the home LAN system, it is essential to change the configuration of the home LAN system. A technology that places importance on such a capability is disclosed in "Optical Composite Home Network System" of Japanese Patent Laid-Open No. 9-16498. In this system, the information distribution board is provided with a photoelectric composite outlet for connecting a power line cable and two optical fiber cables between each device connected to the LAN and the information distribution board,
The power line cable is used to supply power to the equipment, and the two optical fiber cables are used as upstream / downstream signal lines.
The optical fiber cable can be used as a transmission line for any device. A device-compatible interface, such as C
An ATV tuner, a telephone modem, etc. should be inserted and set as a plug-in unit in the information distribution board, and the plug-in unit and each optoelectronic composite outlet can be arbitrarily connected by optical connection switching means. The connection control is controlled by the control means in the information distribution board, so that it is easy to deal with the increase / decrease of equipment and the like.

[0004]

In recent years, as the number of financial transactions in the network environment such as home banking and credit card settlement using the Internet has increased, a credit card number, a cash card personal identification number, an Internet ID, a password, etc. are kept secret. The transmission and reception of highly necessary data is increasing. On the other hand, the progress of wiretapping technology is remarkable, and in addition to wiretapping of wireless LAN, when data is sent by LAN of metal cable, it is also possible to intercept weak electromagnetic waves generated from the cable in accordance with electric signals and intercept transmission data. It is possible. Home LA
In order to maintain the security of the N system, it is conceivable to use encryption technology or use an optical fiber transmission line that hardly leaks information. It is desired to configure a home LAN system by selecting the security technology.

An object of the present invention is to provide a home LAN system in which the transmission path is constructed in consideration of the amount of information to be transmitted, security and economy.

[0006]

According to the present invention, data transmission and reception between a plurality of systems of LANs configured by using different transmission media and devices connected to each LAN via these LANs, and control thereof. A home LAN system including a control device for performing at least one of the plurality of systems, wherein at least one system of the plurality of systems of LANs is an optical LAN using an optical fiber as a medium, and performs transmission / reception of highly confidential data. Disclosed is a home LAN system in which the device is configured to be connected to the optical LAN.

Further, the present invention discloses the domestic LAN system, wherein in the above-mentioned domestic LAN system, the control device includes an external connection transmitting / receiving means for connecting to an optical fiber transmission line. To do.

Further, in the home LAN system according to the present invention, the control device includes an external connection transmitting / receiving means for connecting to a transmission line other than an optical fiber, and the external connection transmitting / receiving means comprises: Disclosed is a home LAN system having an encryption means for encrypting / decrypting data.

Further, in the home LAN system described above, the present invention inserts a low-pass filter for cutting off a frequency component higher than the AC frequency of electric power into the power line drawn into the house from the outside, and then connecting the power to each device. Home LA characterized by being configured to supply electric power
An N system is disclosed.

Further, according to the present invention, in the above-mentioned home LAN system, data transmitted / received to / from the outside or data transmitted / received by a device connected to a LAN other than an optical LAN is data requiring confidentiality. There is a notification that there is a code attached to the data itself, a code attached to the communication data requesting the transmission of the data, or a code provided to the communication data notifying the transmission of the data. When the control device detects the code and detects that the device trying to transmit or receive the data is connected to a LAN other than the optical LAN, the control device warns the device. Disclosed is a home LAN system having a function of sending a message to notify the user.

Further, the present invention provides a home LAN as described above.
In the system, the control device causes a device to receive data at a timing specified by a delay time measurement storage unit that measures and stores in advance the time required until the data transmitted from the device is received by each device. Alternatively, when a command is received and an operation corresponding to the command is started, the control device reads the delay time corresponding to the device stored in the delay time measurement storage means, and the delay time is earlier than the designated timing. Disclosed is a home LAN system having a synchronous control means for transmitting the data or command at a timing.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of a home LAN system according to the present invention. The control device 1 has a role of connecting a plurality of home LANs to the outside. The bus 100 via the O / E / E / O conversion unit 104 that performs optical-electrical bidirectional conversion of an optical signal via an optical fiber for bidirectional communication such as telephone and Internet data.
Further, received waves of TV satellite broadcasts and terrestrial broadcasts are digitized by tuner units 102 and 103 and input to the bus 100. Large capacity hard disk 105
The exchangeable media drive 106 for long-term storage, such as a VCR or a DVD, is used for recording data transmitted from the outside for temporary storage, reproducing recorded images, and the like. Further, image data input from the outside via the tuner units 102 and 103 or data recorded in the hard disk 105 or the like is distributed to each device via various LANs described later. The control of these operations is executed by the arithmetic control unit 101 and the memory unit 107. The housing of the control device 1 is electromagnetically shielded so that electromagnetic noise from internal electronic devices and wiring does not leak outside.

An optical fiber 120 is used as a home LAN.
There are three systems: an optical LAN using the above as a medium, a wireless LAN using the electromagnetic wave 121, and a power line LAN that carries signals as high-frequency components on general power lines 122 and 123.
In addition to this, 100BASE-T is used as the medium of LAN.
You may use

In the optical LAN, one optical fiber is allocated to each of the downstream direction from the control device 1 to each device and the upstream direction from each device to the control device 1, and full duplex communication is ensured. A digital high security telephone 3, a high security personal computer 4, a high security interactive television device 5, a digital video camera 6, a general television receiver 7 and the like are connected to the optical LAN. In this optical LAN, the amount of transmission data from the control device 1 to each device is larger than the amount of data from each device to the control device 1 and high speed is required, such as image distribution.
An LD (Laser Diode) module is more suitable than an LED for high-speed E / O conversion for converting an electrical signal into an optical signal. However, since the LD module is expensive, in this configuration example, the conversion unit is used. There is only one, and one E / O converter 108 configured by using a high-speed LD module is provided, and this output optical signal is branched using a branching device 109 for waveguide application, and each device 3 to 7 Have been delivered to. By doing so, the expensive E / O converter is reduced, and the cost of the control device 1 is reduced. In addition, in an optical LAN for home use, particularly when an LD module having a large output is used as a light source, it is desirable for safety that its emission center wavelength is in the visible light band. This is a large output L
Most D module light sources have an emission center wavelength in the infrared, but the human eye does not detect infrared, so in order to avoid laser light entering the eye during wiring work or disconnection, and avoiding damage. is there.

In the wireless LAN, since the communication medium 121 is an electromagnetic wave and it is not necessary to lay cables or fibers, it is necessary to use portable information equipment such as PHS or mobile phone 10a or mobile equipment such as mobile personal computer 10b. Suitable for communication. However, wireless L that uses the radio band
Unless a shielding facility is provided in the AN, radio waves naturally leak out of the home and there is a high possibility that they will be heard. In addition, light waves such as infrared rays can be used as a medium for a wireless LAN. In this case, since the light waves themselves have a high straight traveling property, if the directivity is increased, they will not leak to the outside, but it is difficult to secure an optical path. It will also hinder the connection of multiple devices. Therefore, the light is spread and radiated into the room, and in that case, there is a high possibility that data leaks out through a window or the like.

The power line LAN uses the power line 123 in the home as a medium, and can be connected to the LAN simply by inserting it into an electric outlet in the home. The electric power taken in via the main breaker 124 and the noise cut filter 12f is transmitted via the distribution board 126 to the control device 1, the electric light 9a, and the air conditioner 9.
b, cooking equipment 9c, laundry-related equipment 9d, bath or water boiling equipment 9e, storage equipment 9f such as a refrigerator, and the like. Electric power to the control device 1 is supplied to the power line 122 and the low-pass filter 12.
The power is supplied to the power supply unit 128 of the control device 1 via 7. The power line modem 130 converts the data signal from the arithmetic and control unit 101 into a power line carrier signal, and the signal is a high pass filter 129, a power line 122, a distribution board 126, and a power line 12.
It is transmitted as ON / OFF control or reservation data to each device via 3. These data do not require large capacity communication and are suitable for the power line LAN including the general telephone 8. In recent years, the electromagnetic waves of individual electric appliances have been shielded, but electromagnetic waves are always generated around the power line when an electric signal flows through the power line as a flow of electrons. Although this electromagnetic wave is weaker than that of a wireless LAN, it can be intercepted from outside the home because it has a strength that can be received by an appropriate antenna. This situation is the same when a metal cable connection such as 100BASE-T is used. Including the case of a wireless LAN, it is not cost effective to shield the entire house from electromagnetic waves in order to prevent electromagnetic wave leakage. Also, if it is not treated properly, it will reflect in the room,
There is a possibility that the electromagnetic waves contained inside may cause high frequency heating or adversely affect electromagnetic noise as internal electromagnetic noise to people and objects inside. On the contrary, at home, wireless devices such as mobile phones and radios that are not connected to the LAN cannot be used. Therefore, the shielding of the whole house is not adopted.

According to the configuration shown in FIG. 1 described above, devices such as a personal computer 4, an interactive television 5, a video camera 6 and a general television 7 are incorporated in an optical LAN in order to transmit and receive a large amount of data at high speed. There is. Further, since the optical signal does not leak from the optical fiber and no electromagnetic wave is generated around the fiber, the possibility that the communication data will be intercepted from the outside is extremely low. Therefore, not only devices that require large-capacity communication, but also Internet connection, Internet shopping, home banking, etc.
A highly secure telephone 3 for sending and receiving important data requiring confidentiality such as an ID number, a personal computer 4, a two-way T
By transmitting and receiving with the optical LAN via V5, it is possible to prevent interception of important data. Regarding the general television 7, the control signal such as the channel switching signal is routed through the power line LAN to simplify the configuration and to make the economy more economical.

In addition to suppressing the data leakage due to the optical LAN connection at home, an optical fiber directly connected to the control device 1 is used as a medium for transmitting / receiving data to / from the outside so that it can be used outdoors. It is possible to reduce the possibility that the important data will be leaked due to the electromagnetic waves being intercepted on the communication path. Furthermore, if the internal power line modem communication data leaks to the outside through the power line, it will lead to data leakage even if it is not important data, and it will also become a noise source to the outside, so between the external power line and the household power line. Is a noise cut filter 125 that cuts off frequency components above the power frequency.
By providing the, the security of data can be further enhanced.

As described above, the structure of FIG. 1 is devised to enhance security in terms of hardware, but a software-like mechanism for further improving security is also incorporated. This is because the control device 1 monitors whether or not the data transmitted on the LAN is important data that needs to be kept secret, and the user or the device that is trying to send or receive the important data passes through a LAN other than the optical LAN. If the control device 1 is attempting to transmit the above, the control device 1 issues a warning to the user or the used device or stops the transmission. This avoids the risk of inadvertently transmitting and receiving important data without considering the possibility that the user or the device will be intercepted. Here, as a method of monitoring whether or not the control device 1 is the important data, the header part or the data part of the packet normally used in the transmission on the LAN is provided with a code indicating the important data, and this can be monitored. Good. More specifically, notice that important data itself or a code attached to the header part of the data, data requesting the transmission of data, a code attached to the header, or data with high confidentiality need to be transmitted. This is done by identifying the data or the code provided in the header thereof.

Further, although not security, the configuration of FIG. 1 also has a time adjustment function in the home LAN system. Currently, many clocks such as televisions and videos have a function of automatically correcting the time according to the time signal of terrestrial TV waves distributed to each device. But,
In the home LAN as shown in the figure, the terrestrial wave is not directly delivered to each device, so that there is a possibility that a time shift may occur. Therefore, the transmission delay time to each device is stored in the control device in advance, and the control device 1 issues an instruction for time adjustment to each device at an appropriate time based on the data, so that the clock of each device is controlled by the control device. To match the clock of. By this method, if the time can be corrected precisely and the clocks of the control device and each device can accurately time the time, not only asynchronous packet communication in the home LAN but also, for example, It is possible to operate even devices connected to LANs having different speeds, such as an optical LAN and a power line LAN, in synchronization. On the contrary, for example, two devices to be synchronized are both connected to the optical LAN and the delay time is almost the same. Therefore, if they cannot be synchronized as they are, a specific time interval is specified.
By transmitting the transmission data to one device to start the operation after the lapse of the specified time interval at the timing considering the delay time and the specified time interval, and transmitting the data to the other device considering only the delay time. It is possible to synchronize two devices. L of 3 or more devices or multiple systems
Even when the devices are synchronized over the AN, the synchronization can be performed by the same method.

FIG. 2 is a block diagram showing another example of the configuration of the home LAN system according to the present invention. The configuration of the optical LAN is different from that of FIG. Is different. For the optical LAN, E for each device that performs bidirectional transmission connected by the optical LAN
The / O / O / E converters 201 to 204 are provided, and only the one-way transmission general televisions are connected via the E / O converter 205. In this way, if the E / O conversion unit is independently provided for each optical connection, the speed required for E / O conversion only needs to satisfy the connected devices, so that low-speed devices can be used. Can use a low speed but relatively inexpensive light source such as an LED. Moreover, since the optical branching device as shown in FIG. 1 is not necessary, there is an advantage that even if the optical connection is expanded, it is only necessary to expand the E / O / O / E converter and the optical transmission / reception controller. . Further, in the configuration of FIG. 2, each E / O / O / E
The conversion unit is connected to the optical transmission / reception unit control unit, but if the arithmetic control unit 101 is sufficiently high speed, the optical transmission / reception unit control unit is eliminated and the arithmetic control unit directly outputs each E / O / O / E conversion unit. It is also possible to make it the structure which controls.

An optical fiber is not used for data communication with the outside, a power line modem 210 for external connection and a high-pass filter 211 are provided between the bus 100 and the power line, and a high-frequency component is superimposed on the power waveform for communication. Utilizes transportation. In this case, the power line modem 13 for home LAN
It is necessary to prevent the data signal between 0 and the power line modem 210 for external connection from interfering with each other. This is ensured by the noise cut filter 125 cutting off components above the power frequency.

When power line carrier is used for data transmission / reception to / from the outside, electromagnetic waves leak from the power line so that it can be easily intercepted. As a countermeasure against this, an encryption circuit is provided in the power line modem 210, and when important data is transmitted and received, data encryption and restoration processing is performed by this circuit. As in the case of FIG. 1, it is determined whether the important data for this purpose is the code attached to the data itself, the code attached to the communication data requesting the transmission of the data, or the data highly confidential. This is performed by the control device 1 identifying the code provided to the communication data that gives advance notice of transmission. Note that the encryption and decryption work can be performed by software processing not by the encryption circuit but by the calculation control unit if the calculation control unit 10 is sufficiently fast and has a sufficient processing capacity. Further, as a measure for preventing data leakage from an external connection line, it is effective to use encryption by frequency hopping.

FIG. 3 is a block diagram showing still another configuration example of the home LAN system according to the present invention.
Differs from the configuration of the optical LAN, and data transmission / reception with the outside is configured by a line using a metal cable such as a telephone line. Regarding an optical LAN in a home, all the optical fibers connecting the respective devices have a single-core connection structure, and each E / O conversion unit and O / E conversion unit are also configured. The optical fiber 302f that passes the optical signal from the E / O converter 302 and the optical fiber 301f that guides the optical signal from each device to the O / E converter 301 are combined into a single-core fiber 303f by the Y branch device 303. After that, it is divided by a one-to-many branching device 304 and connected to each device by an optical fiber 305. According to this configuration, in this embodiment, the optical signal is branched through the branching device 304,
The optical signal is likely to be weak and an optical signal having a higher intensity than that of the configuration example of FIG. 2 is required. An optical filter that reflects or transmits only a specific wavelength body is used as 303, and the upstream optical signal to the O / E conversion unit 302 is prevented from leaking to the E / O conversion unit 301, thereby at least the upstream optical signal. The decrease in strength due to the Y-branch can be reduced.

As the communication line using the metal cable, a telephone line, an ADSL line, an ISDN line, an Ethernet (registered trademark) line, etc. can be used, and the interface is performed by the modem 310. Also in this case, as in the case of FIG. 2, in order to enhance the security of the external line, the modem 310 is provided with an encryption circuit, or the important data is protected by the encryption / decryption processing of the arithmetic control unit 100.

FIG. 4 shows a modification of the home LAN shown in FIG. 3, showing only the portion related to the optical LAN.
In this configuration, as in the case of FIG.
The conversion unit 301 and the E / O conversion unit 302 are integrated into a single-core optical fiber by the Y branch device 303, but the distribution to each device is performed by switching by the optical switch 401 regardless of the branch device. ing. In the case of such a configuration, while connected by the optical switch, the connected device is the O / E conversion unit 301 and the E / O conversion unit 302 of the control device 1.
Since it can be used exclusively, it is possible to use an inexpensive LED, LD module or the like in the visible light band, which has a relatively weak light output, as the E / O converter.

[0027]

According to the present invention, there is an effect that an economical and safe home LAN system can be constructed in consideration of both required transmission information amount and security for each device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a home LAN system according to the present invention.

FIG. 2 is a block diagram showing another configuration example of a home LAN system according to the present invention.

FIG. 3 is a block diagram showing still another configuration example of the home LAN system according to the present invention.

FIG. 4 is a diagram showing a modification of the home LAN system of FIG.

[Explanation of symbols]

1 control device 3 high security telephone 4 High security PC 5 High security TV equipment 6 digital video camera 7 General TV 8 general telephone 9a electric light 9b Air conditioning equipment 9c cooking equipment 9d Laundry related equipment 9e Bath or water heater 9f Storage equipment such as refrigerators 10a mobile phone 10b mobile computer 120 optical fiber 121 electromagnetic wave 123 power line 130, 210 Power line modem 401 optical switch

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Makoto Shimaoka             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center (72) Inventor Masaya Horino             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center F term (reference) 5K002 AA05 BA04 BA13 DA10 FA01                       GA06                 5K033 AA04 AA09 BA01 BA14 BA15                       BA16 CA11 CC01 DA01 DA06                       DA16 DA18 DB02 DB06 DB08                       DB10 DB22 DB23

Claims (6)

[Claims] 1. A plurality of systems of LAN configured by using different transmission media, and each LAN via these LANs.
A home LAN system including a control device for transmitting and receiving data to and from a device connected to the optical fiber, wherein at least one of the plurality of LANs is an optical fiber using an optical fiber as a medium. A home LAN system characterized in that the device is a LAN, and a device for transmitting and receiving data that needs to be kept secret is connected to the optical LAN. 2. The home LAN system according to claim 1, wherein the control device includes an external connection transmitting / receiving unit for connecting to an optical fiber transmission line. 3. The home LAN system according to claim 1, wherein the control device includes an external connection transmission / reception unit for connecting to a transmission line other than an optical fiber, and the external connection transmission / reception unit includes: Domestic L characterized by having an encryption means for encrypting / decrypting data
AN system. 4. The home LAN system according to claim 1, wherein a low-pass filter for cutting off a frequency component higher than an AC frequency of electric power is inserted into a power line drawn into the house from the outside, and then connected to each device. A home LAN system characterized by being configured to supply electric power. 5. The home LAN system according to any one of claims 1 to 4, wherein data transmitted / received to / from the outside or data transmitted / received by a device connected to a LAN other than an optical LAN is transmitted. The data that requires confidentiality is provided in the code attached to the data itself, the code attached to the communication data requesting the transmission of the data, or the communication data notifying the transmission of the data. When the control device detects the code and is about to transmit or receive the data, the device other than the optical LAN is
The home LAN system, wherein the control device has a function of sending a warning to the device to notify the user when it is detected that the device is connected to the AN. 6. The home LAN system according to any one of claims 1 to 4, wherein the control device measures in advance a time required until data transmitted from the control device is received by each device. The delay time measurement storage means to be stored and the control device are stored in the delay time measurement storage means when receiving data at a timing specified by a device or receiving a command and starting an operation corresponding to the command. A home LA having a synchronous control means for reading a delay time corresponding to the device and transmitting the data or command at a timing earlier than the designated timing by the delay time.
N system.