Patent Application
20050239400
1. Field of the Invention
The present invention relates to a radio access line extending device, and more particularly to a radio access line extending device for extending a subscriber radio access line by using as a communication line an indoor electric power line arranged within a subscriber's home.
2. Description of the Related Art
In a conventional communication network system, individual dedicated lines are wired for respective terminal devices as transmission media (transmission line). Under the circumstances, a large amount of labor is given for engineering works such as the new wiring, addition, or transfer of dedicated lines, and there incurs a large amount of waste such that the dedicated lines that become unnecessary after modifications are left over.
Under the above circumstances, a communication network system using as a communication line an indoor electric power line has been proposed (for example, refer to JP 2001-094482 A).
However, in the case where an indoor electric power line is used for a communication line, it is impossible to satisfactorily take advantage of the functions of the network without providing means for managing the respective terminal devices connected to the indoor electric power line and monitoring a state of a network structured by the indoor electric power line. For that reason, in the conventional communication network system disclosed in JP 2001-094482 A, a communication control unit is provided, which is connected to the indoor electric power lines of respective systems in the vicinity of a distribution switchboard and is in turn connected to an external communication network, and the communication control unit conducts communication control of the communication network using the indoor electric power lines and communication control in association with the external communication network.
In recent years, attention has been rapidly paid to a radio communication technology. When the radio communication technology is going to be applied to the conventional system disclosed in the above-mentioned JP 2001-094482 A, because a radio base station is generally placed on an outdoor electric pole. Therefore, it is necessary to locate a subscriber outdoor device outside a room, for example, at a veranda and to connect an indoor electric power line to the subscriber outdoor device for the purpose of conducting radio communication with the radio base station within the room. To achieve this, engineering works for piercing a wall are required in the aim of drawing a power cable for connecting the subscriber outdoor device and the indoor electric power lines into the room. The engineering works cause a problem in that installation costs are high.
In addition, in the case where the above-mentioned power cable is used for power supply and an Ethernet (trade name) cable (hereinafter refer to as “LAN cable”) is employed as the communication line, engineering works for piercing a wall are required in the aim of drawing the LAN cable and the power cable into the room. The engineering works lead to the higher installation costs. Moreover, it is necessary to extend the LAN cable up to the vicinity of a personal computer equipped within the home. This causes a problem in that the installation costs are high.
The present invention has been made to solve the above problems, and therefore an object of the present invention is to provide a radio access line extending device, which does not require such specific engineering works as to pierce an outer wall of a subscriber's home at all, and which lessens the installation costs.
According to the present invention, a radio access line extending device for connecting a radio base station and a subscriber terminal device includes: a subscriber outdoor device for communicating with the radio base station by radio; and a subscriber media converter connected to the subscriber outdoor device for converting communication data which has been received from the radio base station by the subscriber outdoor device in media to output the converted media to a subscriber indoor electric lamp wire. The radio access line extending device also includes a subscriber router that is connected to the subscriber indoor electric lamp wire, receives the communication data which is transmitted through the subscriber indoor electric lamp wire, and outputs the communication data to the subscriber terminal device. In the radio access line extending device, it is desirable that the subscriber outdoor device and the subscriber media converter be connected to each other through a cable, and the cable be drawn into a subscriber's home through a duct hole for an air conditioner.
According to the present invention, there is provided a radio access line extending device, which does not require such specific engineering works as to pierce an outer wall of a subscriber's home at all, and which lessens the installation costs.
In the accompanying drawings:
Subsequently, the operation of the subscriber radio access line extending device according to the first embodiment will be described with reference to
As described above, according to the first embodiment, the indoor personal computer 14 can be connected to the external network through the indoor router 13, the indoor electric lamp wire 12, the subscriber media converter 11, the feeder LAN cable 7, the subscriber outdoor device 6, the radio base station 1, and the communication line 3. In addition, the feeder LAN cable 7 that is to be drawn into the room from the external is drawn into the room through the existing hole 15 for the drain pipe 9 of the air conditioner. As a result, since the feeder LAN cable 7 can be readily drawn into the room without requiring such specific engineering works as to pierce the wall at all, the radio access line extending device with lessening the installation costs can be realized. Also, since the subscriber radio access line can be extended without laying the dedicated communication line within the room, the installation costs can be further reduced.
In the subscriber radio access line extending device according to the second embodiment, as shown in
The air conditioner 30 generates noises, and the noises are conducted by the power cable 29. However, because the noises are cut off by the noise filter 28, the supply of the noises to the power line communication through the indoor electric lamp wire 25 which is attributable to the subscriber media converter 26 can be reduced.
As described above, according to the second embodiment, the same advantages as those in the above-mentioned first embodiment are obtained. At the same time, the supply of the noises to the power line communication which is attributable to the subscriber media converter 26 can be reduced because the noises that are generated in the air conditioner 30 are cut off by the noise filter 28 with the provision of the mains connector 27 having the noise filter 28 between the air conditioner 30 and the indoor electric lamp wire 25.
Subsequently, a description will be given of a subscriber radio access line extending device according to a third embodiment of the present invention.
In recent years, there arises a problem of the security of radio communication. For example, in a radio LAN of 2.4 GHz, a communication data encrypting system that is called “WAP (wire equivalent privacy)” is normally employed. The power line communication in turn raises a problem of security since a plurality of users conduct communication by means of a common electric lamp wire. A method that solves the above problem and allows a subscriber to readily conduct the setting of security on a device will be described with reference to the third embodiment. The structure of the subscriber radio access line extending device according to the third embodiment will be omitted from description because of the same structure as that of the above-mentioned first or second embodiment. Also, in the following description, an example in which the third embodiment is applied to the structure of the first embodiment will be described.
According to the third embodiment, in the structure of the above-mentioned first or second embodiment, the external communication line 3 is connected to the Internet, and an ISP (Internet service provider) that serves an Internet access attributable to the subscriber radio access line distributes keys of cryptography (cryptographic keys) which vary from one subscriber to another.
The subscriber registers the subscriber outdoor device 6, the subscriber media converter 11, and the cryptographic key that has been distributed to the indoor router 13 by means of the personal computer 14.
The radio base station 1 is structured so as to accept only data that has been encrypted by the distributed key and not to accept other data. Also, data that has been encrypted by a certain key can be decrypted by only that key. This makes it possible to prevent the subscriber from another subscriber's data snooping.
Usually, a cryptographic key for the indoor network and a cryptographic key for the access network are separated. On the other hand, in the third embodiment, since those cryptographic keys are standardized, the subscriber is capable of simply conducting setting of the keys.
As described above, according to this embodiment, the same advantages as those in the above-mentioned first and second embodiments are obtainable. In addition, the security of communication is ensured since the radio base station 1 is structured so as to accept only data that has been encrypted by the key distributed by the ISP and not to accept other data, and, at the same time, the subscriber can readily set the cryptographic key of communication since the cryptographic key is registered through the personal computer 14.
Subsequently, a description will be given of a subscriber radio access line extending device according to a fourth embodiment of the present invention.
The collective housing frequently raises such a problem in that there are rooms that can enjoy an Internet access service and other rooms that cannot enjoy the Internet access service even in one collective housing in the case where there is no veranda for locating the subscriber outdoor device depending on the layout of a house, or a veranda does not face the radio base station. In this embodiment, a method for solving this problem will be described.
As shown in
Also, as shown in
As described above, in this embodiment, the same advantages as those in the above-mentioned first embodiment are obtainable. In addition, even in the subscriber's home B34 with no veranda and no location at which the subscriber outdoor device is placed, because the indoor electric lamp wires are connected to each other through the distribution switchboards, the personal computer of the subscriber's home B34 can be connected to the external network through the subscriber router 38, the distribution switchboards 37a, 37b, the subscriber media converter 35, the subscriber outdoor device 32, and the radio base station 31, to thereby enhance the convenience.
Also, since a radio channel that is employed by the subscriber radio access line can be commonly used by a plurality of subscribers, the channel can be saved.
When the indoor electric lamp wire 40 that extends over the respective floors heightwise of the collective housing 4 is in turn connected between the respective rooms through the distribution switchboards, even in the subscriber's homes at different floors or in the case where there is no veranda and there is no location at which the subscriber outdoor device is placed, the personal computer equipped indoors can be connected to the external network, to thereby further enhance the convenience. In particular, the above-mentioned structure is effective in a room at a basement floor or the like.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-125839 | Apr 2004 | JP | national |
