JP2004007375A - Communication repeater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication repeater which realizes prevention of taking a plurality of assignment signals by a terminal, and privacy protection and security improvement for a terminal user simply and at low costs in the communication repeater which repeats the interval between a trunk communication line such as CATV and FTTH and a terminal connected thereto by radio. <P>SOLUTION: The communication repeater is provided with a master station modem 11b which mutually converts a trunk side PPP (Point to Point Protocol) used in a trunk communication line ML, and a TCP/IP which enables a one-to-many communication with a plurality of terminals TEs by using a communication signal assigned by the trunk side PPP, and a PPPoE server 14b which mutually converts the TCP/IP and a terminal side communication protocol in which PPPoE is added to the lower layer of the TCP/IP. The PPPoE server 14b has an authentication function for authenticating whether or not the connection to the trunk communication line ML is permitted to each of the terminals TEs, and a function of dynamically assigning an IP address to each of the terminals TEs. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wireless relay device that relays wireless communication between a backbone communication line such as CATV or FTTH and a terminal installed in each house.
[0002]
[Prior art]
2. Description of the Related Art In recent years, with the rapid spread of data communication, a demand for a high-speed network has been increasing. However, core communication lines provided by wire, such as CATV (cable TV) and FTTH (Fiber To The Home), require introductory wiring work for each house, and indoor wiring work is required even when changing the indoor layout. In many cases, it takes time and money for the user. Particularly, in an apartment house or the like, since a large number of wirings are concentrated in a narrow space, it is desired to spread a wireless communication network which does not require complicated wiring work for each house.
As a system that meets such needs, for example, Japanese Patent Application Laid-Open No. 2000-299848 (Publication 1) proposes a two-way wireless CATV system that uses an existing CATV network and replaces the end of the network with wireless. Have been. This is a wireless communication between a communication relay device (base station) connected to a CATV network (backbone communication line) and a plurality of slave station devices (subscriber stations) by using a radio signal of a communication band of several GHz or more. It is a one-to-many (PMP) two-way wireless communication system for transmitting and receiving data. In this system, the communication relay device relays communication between the slave station device and a predetermined server connected to an upper side of a CATV network, thereby providing not only a connection service to the Internet but also on-demand video data such as a movie. It can be used for communication services that require broadband, such as those provided by.
[0003]
FIG. 3 is a schematic configuration diagram of a conventional PMP two-way wireless communication system.
The conventional PMP two-way wireless communication system is installed in each house, is connected to a plurality of slave station devices 10a connected to a terminal TE such as a personal computer, and a backbone communication line ML (CATV network), and is installed on a telephone pole or the like. And a communication relay device 10b.
Further, the communication relay device 10b includes a master station modem 11b (so-called cable modem), a master station wireless modem 12b, and a master station antenna 13b, and the slave station device 10a includes a slave station wireless modem 11a, and a slave station antenna 12a. Respectively.
The master station modem 11b performs mutual conversion between a communication protocol used in the trunk communication line ML and a communication protocol used for communication with the terminal TE. The master station wireless modem 12b performs mutual conversion between a wired communication band (frequency band) on the backbone communication line ML side and a wireless communication band on the slave station device 10a side. A communication signal with the terminal TE is wirelessly transmitted and received by the wireless modem 12b via the master station antenna 13b.
On the other hand, the slave station device 10a transmits and receives wireless signals to and from the communication relay device 10b via the slave station antenna 12a. Further, the signal transmitted and received by the slave station antenna 12a is mutually converted by the slave station wireless modem 11a into wireless and wired communication bands, and the communication medium is converted. As a communication medium between the slave station device 10a and the terminal TE, for example, a communication medium standardized by IEEE802.3 is used.
[0004]
Generally, PPP (Point to Point Protocol) is adopted as the communication protocol in the trunk communication line ML, and the communication relay device 10b connected to the trunk communication line ML is assigned to each of the communication relay devices 10b (each point). With the signal, a predetermined server connected to the upper side of the trunk communication line ML and each of the communication relay devices 10b can communicate individually (point to point). As the PPP in the backbone communication line ML, a communication protocol adopted in DOCSIS (Data Over Cable Service Interface Specification) which is a standard of a communication device in CATV is known. Hereinafter, the communication protocol in the backbone communication line ML is referred to as backbone PPP.
In addition, between the communication relay device 10b and the terminal TE, a communication protocol capable of performing one-to-many communication between them (hereinafter, referred to as a one-to-many communication protocol) is employed. As this one-to-many communication protocol, TCP / IP which is generally used in personal computers and the like is adopted. Therefore, the master station modem 11b performs mutual conversion between the trunk PPP and TCP / IP (the trunk communication line ML adopts a communication protocol in which the trunk PPP is added below TCP / IP). In this case, the basic PPP is added and removed). In TCP / IP, in order to establish communication, it is necessary to assign an IP address, which is address information, to each of the terminals TE. By including the IP address in the communication signal assigned to each of the terminals TE, the terminal TE can identify the signal assigned to itself from the communication signals. Here, so-called DHCP (Dynamic Host Configuration Protocol) is adopted for the assignment of the IP address, and the IP address is often dynamically assigned by the master station modem 11b every time there is a connection request from the terminal TE. (The IP address assigned in this way is not a so-called global IP address, but a local IP address). This eliminates the need for complicated work such as setting an IP address on the terminal TE side, and eliminates the need for the system administrator to individually manage the IP address of each of the terminal TEs. It will be easier.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional configuration, a limited number of IP addresses (local IP addresses) managed by the master station modem 11b are allocated by DHCP on a first-come-first-served basis (in the order of connection request). When a user connects a plurality of the terminals TE to the slave station device 10a by providing a HUB between the slave station wireless modem 11a and the terminal TE, the IP addresses (ie, A communication signal) is assigned, that is, a plurality of I / P addresses are assigned to one user (a plurality of IP addresses are assigned), and assigned to the terminal TE of another user. There is a problem in that there are not enough IP addresses.
Further, in the above-described conventional configuration, since each of the master station modem 11b and the terminal TE is in an open connection state similar to that of a LAN connection, the user of the user connected to the trunk communication line ML is in the open connection state. In the case where resources such as storage devices are set to be shared in the terminal TE, the existence of the terminal TE of another user (another person) can be known, and in some cases, illegal communication between the terminals TE may occur. There is a problem in privacy and security that an unauthorized access is made. It is also conceivable to add a function of authenticating each of the terminals TE (user) to a predetermined server connected to the upper side of the trunk communication line ML. In this case, the existing server of the trunk communication line ML may be provided. It is necessary to change the communication protocol and the existing communication equipment such as the master station modem 11b, and there is a problem that enormous time and cost are required for constructing the system.
Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a communication relay device for relaying between a backbone communication line and a terminal wirelessly connected to the backbone communication line, by using an address (assignment signal) by the terminal. It is an object of the present invention to provide a communication relay device capable of easily and at a low cost realizing prevention of multiple taking, protection of terminal user privacy and improvement of security.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a method for converting a communication signal into a wireless signal and a wired signal, whereby a predetermined trunk communication line and a plurality of terminals connected to the trunk communication line via wireless communication. A communication relay device that relays communication between the communication device and a communication protocol assigned to the communication relay device by using a basic PPP (Point to Point Protocol) which is a communication protocol used in the main communication line. A mutual conversion between a terminal-side communication protocol, which is a protocol in which PPP is added to a lower layer of a predetermined one-to-many communication protocol that enables one-to-many communication between the communication relay device and the plurality of terminals, is performed. Protocol conversion means for performing, and wireless communication means for mutually converting communication signals according to the terminal-side communication protocol into wireless and wired signals, By comprising comprises a communication relay apparatus according to claim.
As a result, the communication relay device and each of the plurality of terminals can perform individual communication based on PPP, so that a terminal of a certain user connected to the backbone communication line, such as an open LAN connection, The presence of the terminal of another user (other person) cannot be recognized, and unauthorized access between the terminals does not occur. Further, since the existing communication protocol of the trunk communication line (the trunk PPP) is used, existing communication equipment such as a modem can be effectively used.
When a PPPoE function for identifying each of the terminals (users) is added to a predetermined server connected to the upper side of the trunk communication line, a router (IP) is provided between the trunk communication line and the server. Router) cannot be interposed, but according to the present invention, such a restriction does not occur.
That is, PPPoE operates on layer 2 in the OSI reference model, but since the IP router operates on layer 3 which is an upper layer thereof, if a router intervenes during communication, packets based on PPPoE are not relayed. However, by providing the communication relay device at the terminal side of the trunk communication line, that is, at a position where a router does not need to be interposed, a router can be interposed at a higher level than the trunk communication line. Generally, various server computers are often connected via a router on the upper side of the trunk communication line, but according to the present invention, such a connection form can be applied without any trouble.
[0007]
It is also conceivable to provide an authentication means for authenticating whether or not each terminal is permitted to connect to the backbone communication line.
As a result, only terminals (users) registered in advance cannot connect to the backbone communication line, so that one user can simultaneously connect a plurality of terminals to transmit communication signals (addresses) to be assigned to other users. ) Does not run out.
[0008]
It is also conceivable that the terminal is configured to perform authentication as to whether or not each terminal is permitted to connect to the trunk communication line by inquiring a predetermined authentication server connected through the trunk communication line. Can be
This allows the authentication server to collectively manage authentication information (personal information regarding authentication) relating to permission to connect to the trunk communication line, information relating to the connection performance of the respective terminals to the trunk communication line, and the like. Management becomes easier than recording such information in each of the communication relay devices.
[0009]
It is also conceivable to provide address information allocating means for dynamically allocating predetermined address information corresponding to each of the terminals used in the one-to-many communication protocol.
This eliminates the need for complicated work such as setting the address information on the terminal side, and eliminates the need for the system administrator to individually manage the address information for each terminal, thereby facilitating system management. .
Further, for example, the one-to-many communication protocol may be TCP / IP, or the PPP in the terminal-side communication protocol may be PPPoE (Point to Point Protocol over Ethernet) (refer to “the description in this specification”). "Ethernet" is a registered trademark of Fuji Xerox Co., Ltd.). In addition, the PPP in the terminal-side communication protocol may be PPPoA (Point to Point Protocol over ATM). Here, the ATM (Asynchronous Transfer Mode) is a transmission system in an asynchronous transfer mode, and is mainly used for a broadband ISDN (B-ISDN).
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments and examples of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. The following embodiments and examples are mere examples embodying the present invention, and do not limit the technical scope of the present invention.
FIG. 1 is a diagram showing a schematic configuration of a communication relay device X according to an embodiment of the present invention and a one-to-many two-way wireless communication system using the same as a component, and FIG. 2 is a diagram showing an embodiment of the present invention. FIG. 3 is a block diagram showing a configuration of a PPPoE server constituting the communication relay device X, FIG. 3 is a diagram showing a schematic configuration of a conventional communication relay device and a one-to-many two-way wireless communication system including the same, and FIG. FIG. 1 is a diagram illustrating a schematic configuration of a communication relay device X1 according to an embodiment of the present invention and a one-to-many two-way wireless communication system including the same as a component.
[0011]
As shown in FIG. 1, a communication relay device X according to an embodiment of the present invention is connected to a backbone communication line ML (CATV network, FTTH network, or the like) and communicates with a plurality of slave station devices 10a (subscriber stations). By transmitting and receiving data wirelessly between the terminals, the communication between the terminal TE connected to the slave station device 10a and a predetermined server connected to the upper side of the trunk communication line ML is relayed.
This communication relay device X is obtained by adding a PPPoE server 14b between the master station modem 11b (so-called cable modem) and the master station wireless modem 12b of the conventional communication relay device 10b shown in FIG. is there. That is, a master station modem 11b for performing mutual conversion between the main PPP and TCP / IP, and a wired communication band (frequency band) and a wireless communication for the communication signal by the TCP / IP on the main communication line ML side. A master station wireless modem 12b for performing mutual conversion with a band, a master station antenna 13b for transmitting / receiving a radio signal input / output to / from the master station wireless modem 12b to / from the slave station device 10a, and a master station modem 11b And the PPPoE server 14b provided between the master station wireless modem 12b. As the radio signal transmitted and received by the master station antenna 13b, a radio signal of the IEEE802.11b standard or the like is adopted. Here, the master station modem 11b and the PPPoE server 14b are examples of the protocol conversion unit, and the master station wireless modem 12b and the master station antenna 13b are examples of the wireless communication unit.
On the other hand, the slave station device 10a is the same as the conventional slave station device 10a shown in FIG. That is, a radio signal is transmitted / received to / from the communication repeater X via the slave station antenna 12a, and a signal transmitted / received by the slave station antenna 12a is transmitted by the slave station wireless modem 11a. In addition to being converted to a communication band of each wire and a wired communication band, it is converted to a communication medium (such as a communication medium specified by IEEE802.3) between the slave station device 10a and the terminal TE.
[0012]
As shown in FIG. 2, the PPPoE server 14b includes a communication control unit 141b that performs communication control, a CPU 142b that performs various arithmetic processes such as protocol conversion, and a data storage unit 14b that is a storage unit such as a hard disk or an SRAM. are doing. The PPPoE server 14b responds to a signal obtained by converting the core PPP into TCP / IP, which is an example of a one-to-many communication protocol, by using the TCP / IP (transport layer and network layer). The lower layer (data link layer and / or physical layer) is converted into a protocol (corresponding to the terminal-side communication protocol) in which a so-called PPPoE (Point to Point Protocol over Ethernet) is added, and the terminal TE converts the trunk communication line. The reverse conversion is performed on the communication signal flowing to the ML side. Thus, the communication relay apparatus X and each of the terminals TE can individually (point-to-point) communicate with each other using the communication signal assigned to the communication relay apparatus X in the trunk PPP. Therefore, like the open LAN connection, the presence of the terminal TE of another user (other person) from the terminal TE of one user connected to the trunk communication line ML via the communication relay device X is Recognition becomes impossible, and illegal access is not made between the terminals TE. That is, the conventional problems of privacy and security are solved. Details of PPPoE are specified in RFC2516. The details of PPP are defined in RFC1661.
[0013]
Further, the PPPoE server 14b has an authentication function for authenticating whether or not each of the terminals TE (user) is permitted to connect to the backbone communication line ML (in the function of the authentication means, Equivalent). This is because when the terminal TE requests connection to the trunk communication line ML, the data storage unit 143b of the PPPoE server 1b or the trunk communication based on the user ID and password included in the connection request. This is a function for checking a user ID and a password registered in advance in a predetermined server connected to a higher level of the line ML, and permitting connection to the trunk communication line ML only when the user ID and the password match. At this time, if the user ID and the password transmitted from the terminal TE are related to the already connected terminal TE, no new connection is permitted. In addition, PPPoE client software, which is a program for executing the input of the user ID and password and the transmission of the connection request based on PPPoE, is installed in the terminal TE. Only when the connection request to the trunk communication line ML is authenticated, an IP address is assigned by the master station modem 11b (or the PPPoE server 1b), and connection to the trunk communication line ML is made. .
As a result, only the terminal TE (user of the terminal) registered in advance can connect to the trunk communication line ML, so that it is possible to prevent a plurality of IP addresses from being obtained when an IP address is assigned on a first-come, first-served basis. The problem that the IP address to be assigned to the terminal TE of the user becomes insufficient is solved.
[0014]
In addition, so-called DHCP (Dynamic Host Configuration Protocol) in which an IP address is dynamically assigned for each connection is adopted for the assignment of the IP address. This eliminates the need for complicated work such as setting an IP address on the terminal TE side, and eliminates the need for the system administrator to individually manage the IP address of each of the terminal TEs. It will be easier.
Further, the PPPoE server 14b has a function of recording connection result information on the connection result of each of the terminals TE to the backbone communication line ML in the data storage unit 143b. The connection result information includes, for example, a user ID that has made a connection request, a connection date and time, an assigned IP address, a connection destination (to which server on the upper side of the trunk communication line ML has been connected), and a communication speed. , And information on the results of connection failure. The connection result information is transmitted to a predetermined server connected to the upper side of the backbone communication line ML at a predetermined timing (periodically or in response to a request from a server on the upper side of the backbone communication line ML). You. This makes it possible to provide various communication connection services such as charging a user according to a connection time, a communication speed, and the like.
[0015]
【Example】
In the communication relay device X, the PPPoE server 14b has an authentication function of authenticating whether or not each of the terminals TE (user) is permitted to connect to the trunk communication line ML. The present invention is not limited to this, and the authentication of whether or not each of the terminals TE (user) is permitted to connect to the backbone communication line ML is performed by a predetermined authentication connected via the backbone communication line ML. A communication relay device X1 which is an embodiment configured to perform the inquiry by inquiring the server is also conceivable.
FIG. 4 shows a schematic configuration of a communication relay device X1 and a one-to-many two-way wireless communication system including the same as a component.
As shown in FIG. 4, the configuration of the communication relay device X1 is not different from the configuration of the communication device X, and the configuration of the PPPoE server 14b constituting the communication relay device X1 is also the same as the configuration shown in FIG. . The communication relay device X1 is different from the communication device X only in the function of the PPPoE server 14b (the function of a predetermined program executed by the CPU 142b (see FIG. 2)) regarding the authentication of the terminal TE (user). It is.
When the PPPoE server 14b of the communication relay device X1 receives a connection request from the terminal TE to the trunk communication line ML, the PPPoE server 14b performs predetermined encryption on the user ID and the password included in the connection request, and performs encryption. By transferring the user ID and the password to the predetermined authentication server 16c connected through the trunk communication line ML, the authentication as to whether or not to permit connection to the trunk communication line ML is performed by the authentication server. Contact 16c. Although it is conceivable that this encryption is not performed, it is preferable to perform encryption for security. Here, the authentication server 16c is, for example, a computer configured to execute a program that implements a well-known authentication protocol such as RUDIUS or TACACS + and DHCP.
The authentication server 16c is connected to the trunk communication line ML via a cable modem 11c for performing mutual conversion between the trunk PPP and TCP / IP. Between them, a router 15c (IP router) is provided as needed.
[0016]
On the other hand, in the authentication server 16c, based on the received user ID and password (decryption processing is performed as necessary), the authentication server 16c is registered in advance in storage means such as a hard disk of the authentication server 16c or another file server. The user ID and the password are compared with each other, and if they match, a response indicating that connection to the trunk communication line ML is permitted and an IP address (dynamically assigned by DHCP) assigned to the terminal TE. Otherwise, a response not to permit the connection is returned to the PPPoE server 14b. At this time, if the user ID and the password transmitted from the terminal TE via the PPPoE server 14b relate to the terminal TE already connected, no new connection permission is made. Further, the point that the terminal TE is installed with the PPPoE client software which is a program for executing the input of the user ID and the password and the transmission of the connection request based on the PPPoE is the same as the above-described embodiment. . Then, the PPPoE server 14b receives the response from the authentication server 16c and the IP address (only when it exists), and responds to permit connection to the backbone communication line ML and the assigned IP address. Only when the IP address is received, the PPPoE server 1b connects to the main communication line ML using the IP address.
As a result, only the terminal TE (user of the terminal) registered in advance can connect to the trunk communication line ML, so that it is possible to prevent a plurality of IP addresses from being obtained when an IP address is assigned on a first-come, first-served basis. The problem that the IP address to be assigned to the terminal TE of the user becomes insufficient is solved.
In addition, the authentication server stores authentication information (permission information relating to authentication such as the user ID and password) relating to connection permission to the main communication line and the connection result information relating to the connection result of the terminal TE to the main communication line ML. Since the information can be collectively managed on the 16c side, the management is easier than recording the information in each communication relay device. Further, as described above, the PPPoE operating on the layer 2 in the OSI reference model is completed on the lower side (the terminal TE side) from the communication relay apparatus X1, and therefore, as shown in FIG. The present invention is applicable even when interposed between the authentication server 16c.
[0017]
【The invention's effect】
As described above, according to the present invention, a plurality of terminals can be individually (point-to-point) wirelessly communicated using a communication signal allocated by the PPP on the backbone communication line. As described above, the presence of the terminal of another user (other person) cannot be recognized from the terminal of one user connected to the main communication line, and unauthorized access between the terminals does not occur. That is, the conventional problems of privacy and security are solved.
Also, by having an authentication function or an authentication inquiry function to an upper-level authentication server, only terminals (users) registered in advance cannot connect to the backbone communication line. It is possible to prevent a plurality of IP addresses (that is, communication signals) from being generated, thereby solving the problem that IP addresses to be assigned to the terminals TE of other users are insufficient.
Also, by dynamically allocating the IP address, complicated work such as setting of the IP address on the terminal side becomes unnecessary, and it becomes unnecessary for the system administrator to individually manage the IP address of each terminal. , System management becomes easy. In addition, the above can be realized simply and at low cost without changing the existing communication protocol of the backbone communication line and the equipment such as the modem corresponding thereto.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration of a communication relay device X according to an embodiment of the present invention and a one-to-many two-way wireless communication system including the same as a component.
FIG. 2 is a block diagram illustrating a configuration of a PPPoE server included in the communication relay apparatus X according to the embodiment of the present invention.
FIG. 3 is a diagram illustrating a schematic configuration of a conventional communication relay device and a one-to-many two-way wireless communication system including the same as a component.
FIG. 4 is a diagram showing a schematic configuration of a communication relay device X1 according to an embodiment of the present invention and a one-to-many two-way wireless communication system using the same as a component;
[Explanation of symbols]
10a: slave station device
10b: Conventional communication relay device
11a: slave station wireless modem
11b: Master station modem (cable modem)
12a: slave station antenna
12b: Master station wireless modem
13b: Master station antenna
14b: PPPoE server
141b: Communication control unit
142b CPU
143b Data storage unit
15c ... Cable modem
16c: Authentication server
ML: Backbone communication line
TE ... terminal

Claims (6)

A communication relay device for relaying communication between a predetermined backbone communication line and a plurality of terminals connected to the backbone communication line via wireless communication by mutually converting communication signals into wireless and wired signals. At
A point-to-point protocol (PPP), which is a communication protocol used in the backbone communication line, and a communication signal allocated to the communication relay apparatus by the backbone PPP, between the communication relay apparatus and the plurality of terminals. Protocol conversion means for performing mutual conversion between a terminal-side communication protocol which is a protocol obtained by adding PPP to a lower layer of a predetermined one-to-many communication protocol which enables one-to-many communication;
Wireless communication means for mutually converting communication signals according to the terminal-side communication protocol into wireless and wired signals;
A communication relay device comprising: 2. The communication relay device according to claim 1, further comprising an authentication unit configured to authenticate each of the terminals as to whether to permit connection to the trunk communication line. 2. The apparatus according to claim 1, wherein each terminal is configured to perform authentication as to whether or not to permit connection to the trunk communication line by inquiring a predetermined authentication server connected through the trunk communication line. The communication relay device according to the above. 4. The communication relay device according to claim 1, further comprising address information allocating means for dynamically allocating predetermined address information corresponding to each of said terminals used in said one-to-many communication protocol. The communication relay device according to claim 1, wherein the one-to-many communication protocol is TCP / IP. The communication relay device according to any one of claims 1 to 5, wherein the PPP in the terminal-side communication protocol is PPPoE (Point to Point, Protocol, over Ethernet).

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