Communication system and method for using any communication network therewith

A communication system is provided that allows the same mobile terminal to be used to perform communication even if a network other than a mobile communication network is used and allows to the communication to be maintained across networks, and is capable of collectively managing charges for the networks.An information service network comprises a Mobile IP HA device, an AAAH device for managing and authenticating a mobile terminal and receiving accounting information, a VOIP device for converting voice data transferred to and from the Internet into real voice, and a service device, which may be any application server. Various networks, such as a public telephone network, mobile communication network, private IP network, and supermarket/convenience store network, have an FA device for registering the position of the mobile terminal with the HA device and an AAAL device for exchanging authentication and accounting information with the AAAH device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a communication system and a method for using a communication network therewith, and in particular, to a method for using any of communication systems, such as a mobile communication network, public telephone network, and private network, that use different communication technologies.

2. Description of the Related Art

Today communication networks, such as a mobile communication network, public telephone network, and private network, can be connected to the Internet by using the IP (Internet Protocol) and allows data to be sent and received to and from each other over the Internet.

A public telephone network is a telephone network that uses cables and has switches connected to telephones at individual homes and companies. A mobile terminal can be connected to the telephone by using wireless communications, such as Bluetooth and IrDA (Infrared Data Association), or cable communications.

The public telephone network is called PSTN (Public Switched Telephone Network). ISDNs (Integrated Services Digital Networks) also fall into this category. The telephone may be a public telephone.

A mobile communication network is a network that uses base stations to wirelessly accommodate mobile terminals. PDC (Personal Digital Cellular), CDMA (Code Division Multiple Access), PHS (Personal Handyphone System) fall into this category.

A private IP network is a network constructed by using the IP, called intranet, and used as LANs (Local Area Networks) in companies and SOHOs (Small Office Home Offices). Mobile terminals can be connected to an adapter in the private IP network by wireless or using cables to perform the same operations as those of a host terminal residing in the private IP network.

However, in the mobile communication system using the conventional mobile communication network, a mobile terminal can move only within the mobile communication network. Therefore another terminal must be used when a public telephone network or other networks are used.

If a network other than the mobile communication network is used through the mobile terminal, charges for both networks must be paid separately because each of the networks uses an independent charge accounting system.

SUMMARY OF THE INVENTION

It is an object of the present invention to solve the above-mentioned problem by providing a communication system and a method for using a communication network therewith that allow the same mobile terminal to be used to perform communication even if a network other than a mobile communication network is used and allows to the communication to be maintained across networks.

It is another object of the present invention to provide a communication system and a method used therewith that are capable of collectively managing charges for individual networks.

A communication system according to the present invention is a communication system to which a mobile terminal can be connected and comprises a plurality of communication networks using different communication technologies, each of the plurality of communication networks uses the Internet Protocol to connect to the Internet, the communication system comprising: an information service network for managing accounting information about the mobile terminal and providing services; a Mobile IP (Internet Protocol) HA (Home Agent) device provided in the information service network for constantly managing which network the mobile terminal exists in and delivering received data to an appropriate network over the Internet; and an FA (Foreign Agent) device provided in each of the plurality of communication networks for sending a position registration request from the mobile terminal to the HA device and transferring data delivered from the HA device over the Internet to the mobile terminal when the mobile terminal is under the coverage of the FA device; wherein the position registration request and a reply corresponding to the position registration request communicated between the HA device and FA device are used to flexibly enable communications between the plurality of communication networks and the continuation of the communications across the plurality of communication networks.

Another communication system according to the present invention comprises, in addition to the above-mentioned components, an AAAL (Authentication, Authorization and Accounting Local) device provided in each of the plurality of communication networks for sending charge information about the network in which the AAAL device is provided over the Internet; and an AAAH (Authentication, Authorization and Accounting Home) device provided in the information service network for managing accounting information about the mobile terminal according to the charge information sent from the AAAL device over the Internet.

According to the present invention, there is provided a method for using a communication network in a communication system which a mobile terminal can be connected to and comprises a plurality of communication networks using different communication technologies, each of the plurality of communication networks use the Internet Protocol to connect to the Internet, the method comprising: providing in an information service network for managing accounting information about the mobile terminal and providing services a Mobile IP (Internet Protocol) HA (Home Agent) device for constantly managing which network the mobile terminal exist in and delivering received data to an appropriate network over the Internet; and providing in each of the plurality of communication networks an FA (Foreign Agent) device the Mobile IP, for sending a position registration request from the mobile terminal to the HA device and transferring data delivered from the HA device over the Internet to the mobile terminal when the mobile terminal is under the coverage of the device; wherein the position registration request and a reply corresponding to the position registration request communicated between the HA device and FA device are used to flexibly enable communications between the plurality of communication networks and the continuation of the communications across the plurality of communication networks.

An method for using a communication network in another communication system according to the present invention provides in each of the plurality of communication networks an AAAL (Authentication, Authorization and Accounting Local) device for sending charge information about the network in which the AAAL device is provided over the Internet, and providing an AAAH (Authentication, Authorization and Accounting Home) device in the information service network for managing accounting information about the mobile terminal according to the charge information sent from the AAAL device over the Internet.

Thus, the mobile communication system according to the present invention is characterized in that a mobile phone terminal can be used in a communication system that can be connected to any of communication networks such as a mobile communication network, public telephone network, and private network without changing settings on the mobile phone terminal.

The mobile communication system according to the present invention provides the function of a Mobile IP FA (foreign agent) connected to the Internet to a network such as a mobile communication network, public telephone network, and private network so that, when a mobile terminal such as a mobile phone terminal is under the coverage of the network, a position registration request is sent to a device that has the function of Mobile IP HA (Home Agent) in an information service network and the HA function constantly manages the mobile terminal to identify an FA in a network where the mobile terminal exists, thereby allowing received data to be delivered to an appropriate network.

Thus, according to the present invention, whichever network the mobile terminal moves into, the position of the mobile terminal is registered with the HA of the information network from the FA in that network, thereby allowing the mobile terminal to use services under the coverage of the network and continue to perform communications when moving from another network without changing settings on the mobile terminal.

Also, the present invention provides the function of indicating a charge for each network from an AAAL (Authentication, Authorization and Accounting Local) of the network to an AAAH (Authentication, Authorization and Accounting Home) of the information service network, therefore the user can uses networks varying in charge without changing settings on the mobile terminal.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

An embodiment of the present invention will be described below with reference to the drawings.FIG. 1is a block diagram of a configuration of a communication system according to one embodiment of the present invention. The communication system according to the embodiment of the present invention inFIG. 1comprises an information service network1, public telephone network11, mobile communication network21, private IP (Internet Protocol) network31, and supermarket/convenience store network41, each of which is connected to the Internet51.

The information service network1is a network operated by a company managing accounting information and providing services and is connected to the Internet51by using IP. The information service network1comprises a Mobile IP HA (Home Agent) device2, an AAAH (Authentication, Authorization and Accounting Home) device3, a VOIP (Voice over IP) device4capable of identifying a network into which a mobile terminal moved, performing authentication, and receiving accounting information, and a service device5. Mobile IP herein is based on RFC2002, which is an standard of IP.

The VoIP device4uses VoIP to converts voice data transmitted over the Internet51into real voice to connect to the public telephone network11and can also directly connect to the mobile communication network21.

Any application servers such as a mail server, WWW (World Wide Web) server, WAP (Wireless Application Protocol) server dedicated to mobile terminals can be provided as the service device5. A private IP network such as an intranet may be used instead of the Internet51.

Networks, such as the public telephone network11, mobile communication network21, private IP network31, and supermarket/convenience store network41, other than the information service network1are connected to the Internet51by using IP.

The networks, including the public telephone network11, mobile communication network21, private IP network31, and supermarket/convenience store network41, have Mobile IP FA (Foreign Agent) devices12,22,32,42, which, when recognizing that mobile terminals17,25,35,45are under the coverage of their networks, register the positions of the mobile terminals with the HA device2in the information service network1that manages locations into which they are moved and AAAL (Authentication, Authorization and Accounting Local) devices13,23,33,43, capable of performing authentication in cooperation with the AAAH device3in the information service network land indicating accounting information to the AAAH device3.

The public telephone network11is a wired telephone network connected to telephones15,16in individual homes and companies through a switch14. The telephone16can be connected with a mobile terminal17by wireless communications such as Bluetooth or IrDa (Infrared Data Association),or by cables. The telephones15,16may be public telephones.

The public telephone network11is called PSTN (Public Switched Telephone network). ISDNs (Integrated Services Digital Networks) also fall into this category.

The switch14is connected to the VOIP device4in the information service network1for sending and receiving voice data without changing the data. The Internet51is used from within the public telephone network11when packet data communication is performed or when voice communication is performed by converting voice data into data packets that can be transmitted over the Internet51by the conversion function provided in the switch14or the mobile terminal17. In this case, the switch14sends and receives the packet data to and from the FA device12.

The mobile communication network21is a network that uses base stations26,27to accommodate the mobile terminal25by wireless and may be a PDC(Personal Digital Cellular), CDMA (Code Division Multiple Access), or PHS (Personal Handyphone System) network. A switch24and the base stations26,27in the mobile communication network21are shown by way of example only and the configuration of the network is not limited to this example.

The Internet51is used from within the public communication network21when packet data communication is performed or when voice communication is performed by converting voice data into data packets that can be transmitted over the Internet51by the conversion function provided in the switch24or the mobile terminal25. In this case, the switch24sends and receives the packet data to and from the FA device22.

The private IP network31is constructed by using IP, is called intranet, and is used as networks such as a LAN (Local Area Network) in companies and a SOHO (Small Office Home Office).

The mobile terminal35is connected to an adapter34in the private IP network31by wireless or cables and is capable of performing the same operations as those of the host terminal36in the private IP network31. If voice communication is performed, the adapter34or the mobile terminal35has the function of converting voice data into data packets that can be transmitted over the Internet51and the adapter34sends and receives packet data to and from the FA device32.

The supermarket/convenience store network41is a kind of private IP network in which POS (Point Of Sales) terminals44,46provided in each of stores are connected to the mobile terminal45by wireless or cables.

The configuration of the supermarket/convenience store network41will be the same as that of the private IP network31described above if the POS terminal44is replaced with the adapter34and the mobile terminal45is replaced with the mobile terminal35.

A host terminal52is connected to the Internet51and performs packet data communication with the mobile terminals17,25,35,45.

Communication performed when a mobile terminal is under the coverage of the mobile communications network21and exists as the mobile terminal25in the network configuration according to an embodiment of the present invention will be described below with reference toFIG. 1.

The mobile terminal25is connected to the mobile communication network21through a wireless connection and base stations26,27by the switch24. The switch24is connected to the FA device22having the function of indicating that the mobile terminal25exists within the mobile communication network21to the HA device2of the information service network1over the Internet51. The AAAL device23has the function of authenticating that the mobile terminal25can be used within the mobile communication network21and indicating accounting information in the mobile communication network21to the AAAH device3in the information service network1.

The VOIP device4in the information service network1is connected to the Internet51and the public telephone network11and has the function of converting an audio packet contained in a packet received from the Internet51into real voice data to send it to the public telephone network11, and vice versa.

FIGS. 2 to 7is sequence charts illustrating the operations of the communication system according to an embodiment of the present invention. The operations of the communication system according to the embodiment of the present invention will be described below with reference toFIGS. 1 to 8.

Referring toFIG. 2, a sequence for performing position registration is shown. First, the mobile terminal25sends a position registration request to the FA device22. The FA device22sends an authentication request to the AAAL device23in the mobile communication network21.

The AAAL device23verifies authentication information about the mobile terminal25. More specifically, it determines whether the mobile terminal25is registered in the mobile communication network21so that it can be used within the network21. If the AAAL device23determines that the mobile terminal25is registered, the AAAL device23sends a authentication request to the AAAH device3in the information service network1.

The AAAH device3verifies authentication information about the mobile terminal25. More specifically, it determines whether the mobile terminal25is registered in the information service network1. If the AAAH device3determines that the mobile terminal25is registered, the AAAH device3sends an authentication confirmation to the AAAL device23. The AAAL device23sends the authentication confirmation to the FA device22.

When the FA device22receives the authentication confirmation, it sends a position registration request to the HA device2in the information service network1. The HA device2recognizes that the mobile terminal25is under the coverage of the FA device22and sends a position registration reply to the FA device22. The FA device22sends the position registration reply to the mobile terminal25, then the position registration sequence ends.

Communication between the host terminal52and the mobile terminal25will be considered below with reference toFIG. 3. A Mobile IP procedure will be described here in accordance with RFC2002, which is a standard Internet material.

For the host terminal52to send data to the mobile terminal25, first the HA device2captures the data. The HA device2encapsulates and sends the packet to the address of the FA device22. The FA device22extracts the encapsulated data and sends it to the switch24under the control of the FA device22. Then the data reaches the mobile terminal25by using wireless communication.

On the other hand, when the mobile terminal25sends data to the host terminal52, the data is sent from the switch24to the FA device22by wireless. The FA device22sends the data to the Internet51without making any change to the data. Then the data reaches the host terminal52.

Voice communication between the mobile terminal25and a telephone15connected to the public telephone network11will considered below with reference toFIG. 4. The mobile terminal25converts voice data into packet data and sends it to the switch24in the mobile communication network21, or the mobile terminal25sends the voice data to the mobile communication network21without converting it and the voice data is converted into packet data in the switch24.

The destination of the packet data is the VOIP device4in the information service network1. Therefore, the packet data is sent from the switch24to the VOIP device4through the FA device22.

The VOIP device4has the function of converting packet data sent to it into voice data. The voice data is provided to the switch14in the public telephone network11over a line connected to the public telephone network11and then sent to the telephone15by following a procedure in the public telephone network11.

Inversely, voice data sent from the telephone15is sent to the VOIP device4in the information service network1through the switch14in the public telephone network11. The VoIP device4converts the voice data into packet data and directs the packet data to the mobile terminal25. The packet data directed to the mobile terminal25is captured by the HA device2according to a Mobile IP procedure and sent to the FA device22.

The FA device22extracts the packet data and sends it to the switch24. Then the data is provided to the mobile terminal25by wireless. The packet data is converted into voice data by the switch24or the mobile terminal25, enabling voice conversation. Communication with the mobile terminal25in the mobile communication network21can also be performed through a similar procedure.

Communication performed when the mobile terminal is in position of the mobile terminal17and is connected by wireless or cables to a telephone connected to the public telephone network. Referring toFIG. 5, a sequence for performing position registration is shown.

First, the mobile terminal17is connected to the telephone16by wireless or a cable and sends a position registration request to the FA device12. The FA device12sends an authentication request to AAAL device13in the public telephone network11. The AAAL device13verifies authentication information about the mobile terminal17. If it is authorized, the AAAL device13sends the authentication request to the AAAH device3in the information service network1.

The AAAH device3verifies the authentication information about the mobile terminal17. If it is authorized, the AAAH device3sends an authentication confirmation to the AAAL device13. The AAAL device13sends the authentication confirmation to the FA device12. When the FA device12receives the authentication confirmation, it sends a position registration request to the HA device2in the information service network1. The HA device2recognizes that the mobile terminal17is under the coverage of the FA device12and sends a position registration reply to the FA device12. The FA device12sends the position registration reply to the mobile terminal17. Then the position registration sequence ends.

Packet communication and voice communication can be performed also in the public telephone network11by following the same procedure as that in the mobile communication network21described above. In addition, by performing position defined by Mobile IP quickly, a mobile phone in the mobile communication network21can be connected to the telephone16connected to the public telephone network11while maintaining communication, and vice versa, and the most inexpensive network can be automatically selected from networks currently available to the mobile terminal17to connect the mobile terminal17to the selected network.

More specifically, one can use a mobile phone over the mobile communication network21on his way home, then, at the instant when the mobile phone detects the phone16connected to the public telephone network11, the connection is switched to the telephone16, thereby automatically allowing the less expensive network to be used.

This sequence will be described below with reference toFIG. 6. While packet communication with the host terminal52is used here as an example, the same sequence is the same for voice communication. The sequence for sending a position registration request to the HA device2from the mobile communication network21is the same as that inFIG. 2.

When the mobile terminal25detects the telephone16connected to the public telephone network11, the mobile terminal25is position-registered with the HA device2as the mobile terminal17through the same sequence as that shown inFIG. 5. After the completion of the position registration, the HA device2changes the destination of data that has been being sent to the FA device22to the FA device12to continue the communication.

When the switch24detects that the mobile terminal25is no longer exists within the mobile communication network21, sends a disconnection request to the FA device22. The FA device22sends the disconnection request to the AAAL device23. Then the AAAL device23sends, in addition to the disconnection information, accounting information to the AAAH device3and the mobile terminal25is released from the mobile communication network21.

A method in which connection is not changed to a newly detected network if its communication charge is higher than that for the present network is shown inFIG. 7.FIG. 7shows an operation performed when a terminal detects that it enters the coverage of the mobile communication network21while communicating over the public telephone network11and the communication charge for the mobile communication network21is higher than that for the public telephone network11. The method for performing position registration by using the public telephone network11is the same as the sequence shown inFIG. 5.

When the terminal detects that it is in the mobile communication network21, it sends a position registration request to the FA device22as a mobile terminal25. The position registration request contains the current communication charge information, for example information indicating that the charge is 10 yen per minute. This communication charge information is contained in an authentication request sent from the FA device22to the AAAL device23.

If the AAAL device23determines that the charge for the mobile communication network21is higher, it returns an authentication rejection to the FA device22without sending the authentication request to the AAAL device3. The FA device22sends position registration rejection information to the mobile terminal25to continue communicating over the public telephone network11. If the mobile terminal17leaves the public telephone network11, it immediately detects a new mobile communication network21and performs position registration regardless of its communication charge information, thereby enabling the communication over the public telephone network11to be passed over to the mobile communication network21.

The above-described procedure is followed also in a case where the mobile terminal moves into the coverage of the private IP network31. The mobile terminal35connected to the private IP network31through the adapter34uses the FA device32and AAAL device33to be authenticated in the AAAH device3and can perform packet data communication and voice communication by using the HA device2.

As described above, each of the public telephone network11, mobile communication network21, private IP network31, and supermarket/convenience store network41has the Mobile IP FA function and therefore the mobile terminals17,25,35,45can performs communication whichever network it moves into and can continue to communicate when changing from one network to another.

In addition, the public telephone network11, mobile communication network21, private IP network31, and supermarket/convenience store network41can indicate its charge to each other, therefore a user can use the networks even if there are differences in charge between them.

Furthermore, if there are difference in charge between the public telephone network11, mobile communication network21, private IP network31, and supermarket/convenience store network41, the mobile terminals17,25,35,45can automatically select a less expensive network.

FIG. 8is a sequence chart of a communication system according to another embodiment of the present invention. While the basic configuration of the communication system according to this alternative embodiment of the present invention is the same as that of the communication system according to the embodiment of the present invention shown inFIG. 1, the function of indicating accounting information is used to extend the scope of the application of the system. Operations of the communication system according to the alternative embodiment of the present invention will be described below with reference toFIG. 8.

A supermarket/convenience store network41includes an FA device42, an AAAL device43, and a plurality of POS terminals44,46. A mobile terminal45can be connected to the POS terminals44,46by wireless or cable.

The supermarket/convenience store network41of course allows for packet communication and voice communication through a position registration request sent to the HA device2as described above with respect to the other networks, and in addition, may have the function of making bank withdrawals through the operation of the POS terminals44,46.

A position registration request is sent from the mobile terminal45. The FA device42and AAAL device43are used to perform position registration in the HA device2. An information service network1is connected to the network of a bank (not shown), or the information service network1itself is the network of the bank. It is assumed in this embodiment that the information service network1itself is the bank network and account numbers and deposit information are stored in a service device5.

The mobile terminal45is operated and an account number and personal identification number are used to obtain deposit information from the service device5. Then the mobile terminal45is operated to indicate an amount to be withdrawn to the service device5. If the service device5authenticates the numbers, the service device5sends a response to the mobile terminal45and indicates the amount to be withdrawn to the POS terminals44,46.

The POS terminals44,46may be machines that can be operated by a salesclerk at a supermarket/convenience store, or may be machines that automatically operates. Money is paid in accordance with the deposit withdrawal information provided to the POS terminals44,46. Then connections from the POS terminals44,46to the FA device42and mobile terminal45are disconnected. When disconnecting from the FA device42, the amount withdrawn plus a service charge is indicated as accounting information to the FA device42. The FA device42provides the accounting information to an AAAL device43on disconnection from the AAAL device43. The AAAL device43provides the accounting information to an AAAH device3.

Thus, according to this embodiment of the present invention, the accounting information is used as the withdrawal information to enable the withdrawal through the POS terminals44,46at a supermarket or convenience store.

As described above, a communication system according to the present invention comprises a plurality of communication networks which mobile terminals can be connected to and use different communication technologies, each of the plurality of communication networks uses the Internet Protocol to connect to the Internet, wherein: a Mobile IP HA device is provided in an information service network managing accounting information about the mobile terminal and providing services, the Mobile IP HA device constantly managing which network the mobile terminal exists in and delivering received data to an appropriate network over the Internet; a Mobile IP FA device is provided in each of the plurality of the communication networks, the Mobile IP FA device sending a position registration request from the mobile terminal to the HA device and transfers data delivered from the HA device over the Internet to the mobile terminal when the mobile terminal is under the coverage of the FA device; and the position registration request and a replay to the request communicated between the HA device and the FA device flexibly enable communications between the plurality of communication networks and the continuation of the communications across the plurality of communication networks. Thus, the communication system has the advantage that the same mobile terminal can be used to perform communication even if a network other than a mobile communication network is used, and the communication can be maintained across networks.

Another communication system according to the present invention, in addition to the above-described components, an AAAL device is provided in each of a plurality of communication networks, the AAAL device sending charge information about its communication network over the Internet; and an AAAH device is provided in an information service network, the AAAH device managing accounting information about a mobile terminal based on the charge information sent from the AAAL device over the Internet. Thus,the communication system has the advantage that charges for the plurality of networks can be managed collectively.