JP2003169081A - Server-side data repeating device, base-station data repeating device, mobile data repeating device, mobile terminal, and address information center - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a mobile terminal to securely communicate data in an efficient route. <P>SOLUTION: For data communication, the mobile terminal 1 stores a terminal VIP address unique to itself in a transmission source address part of a sent packet and sends the packet out, a base-station router BR1 which relays it stores the terminal VIP address in a VIP part, stores its own IP address as a return-destination address in the transmission source address part, and sends the packet out, and a server-side router SR1 which relays it stores the terminal VIP address in the transmission source address part and sends the packet out to a server 3, stores the return destination address in a destination address part of a return packet that the server 3 sends out in response, and stores the terminal VIP address in the VIP part and sends the packet out. The base- station router BR1 having received it sends the return packet out to the mobile terminal 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile terminal for data communication with a server via a wide area network, a data relay device for relaying this data communication, and an address information center for managing address information for data communication. It is suitable for use in data communication between a mobile body and a server on the Internet.

[0002]

2. Description of the Related Art In recent years, mobile data communication has come into wide use, in which mobile terminals such as mobile phones are used to perform data communication with a wide area network such as the Internet. This is realized by the mobile terminal wirelessly connecting to the base station and performing data communication with the wide area network via the segment to which the base station belongs.

[0003]

In this case, since the mobile terminal performs data communication with the wide area network, it uses one address from the address space allocated to the segment to which the base station belongs as its own address. This address space is assigned differently for each segment, so when a mobile terminal moves and the base station with which it communicates changes, if the new base station belongs to a segment different from the previous base station, , The address used until then cannot be used as its own, and one of the address spaces allocated to the segment of the new base station is used.

When the address of the mobile terminal changes due to such movement, the server communicating with the mobile terminal on the wide area network cannot confirm the identity of the mobile terminal, and communication is interrupted as it is. Will end up.

Mobile IP is known as a conventional technique for avoiding this communication interruption. This has the home address in the segment to which the mobile terminal normally belongs, and even when the mobile terminal moves from this segment to another segment, the downlink data to the mobile terminal in data communication is addressed to the home address. It is a communication technology in which a host called a home agent transfers the data to the mobile terminal to avoid communication interruption.

However, with this technique, when the mobile terminal leaves the network to which it normally belongs, the delivery route of the downlink data becomes a detour, and the communication efficiency is not good.

[0007] As another conventional technique, VIP (Vi
There is a communication protocol called "rural Internet Protocol". In the VIP, in addition to the IP address depending on the segment to which the connecting base station belongs, a VIP address that does not change even if the segment is moved is assigned as an identifier of the mobile terminal. A VIP packet, which is a basic unit of communication data in VIP, is an IP included in an IP packet which is a basic unit of normal communication data.
In addition to the header portion, it has a VIP header portion, and the VIP address described above is stored in this portion. If the mobile terminal moves the partner of wireless connection from one base station to another, the IP
The address changes, but the VIP address does not change.
Therefore, if there is a correspondence between the VIP address and the IP address, that is, the VIP address → IP address can be always resolved, the server refers to the VIP address in the communication between the mobile terminal and the server on the Internet. As a result, the identity of the mobile terminal is not lost, and the interruption of communication can be prevented.

[0008] A VIP-compatible router located at a relay point between the segments in the Internet plays a role of performing this address resolution. When the VIP-compatible router relays or receives the VIP packet transmitted by the mobile terminal, the router stores the relationship between the IP address and the VIP address included in the VIP packet. After that VI
When a packet destined for the P address passes through this router, the router will deliver the packet to the IP address corresponding to the VIP address so that the packet will be sent to the correct mobile terminal.

In this packet delivery technology by VIP, it is necessary for any of the routers on the network to support the VIP, but there is no stipulation as to which router corresponds to the VIP, and it depends on the arrangement of the routers to support the VIP. There is a problem similar to mobileIP that it becomes a detour communication path, resulting in inefficient communication.

In view of this problem, it is a first object of the present invention to realize data communication by a mobile terminal capable of surely communicating on an efficient route.

Further, when a mobile terminal belongs to a mobile network installed on a bus or train, the base station which is the connection destination of the router of the mobile network may change due to the movement of the bus or train. However, since there is no change in both the VIP address and the IP address of the terminal, the mobile agent home agent and the VIP compatible router cannot support the movement of the terminal, which causes a problem of communication interruption. is there.

In view of this problem, a second object of the present invention is to realize data communication which enables reliable communication even when a mobile terminal belongs to a mobile network.

[0013]

In order to achieve the above object, the server-side data relay apparatus according to claim 1 connects to a base station segment to which the base station belongs by wirelessly communicating with the base station, and connects to the base station segment. In a data communication performed via a wide area network composed of a plurality of segments, a server belongs to a server, which has a virtual terminal address that does not change even if the base station segment is changed, as one of its own addresses, and the server. A data relay device that relays data communication between a server-side segment, which is a segment, and a wide area network, and is base station data that is sent from a mobile terminal for data communication and is between the base station segment and the wide area network. The transmission data is relayed by the relay device and has a virtual terminal address and a return address that specifies the return destination. When the server receives the reply data, it rewrites the send data information so that the server receives it and sends the reply data to the virtual terminal address. When the reply data is received, the reply data is finally sent to the mobile terminal. The information is rewritten and sent to the return address.

As a result, the server-side data relay device rewrites the transmission data transmitted from the mobile terminal and relayed by the base station data relay device, and the server always transmits the reply data with the virtual terminal address as the mobile terminal address. The server side data relay device further rewrites it,
Since it finally reaches the mobile terminal, even if the mobile terminal changes the connection destination base station, since the server uses the unchanged virtual terminal address for communication, the communication will not be interrupted. Data communication can be reliably performed.

Further, the server side data relay device for rewriting the transmission data and the reply data in this way is between the server side segment and the wide area network, and the base station data relay device is between the base station segment and the wide area network. As a result, the mobile terminal and the server can perform data communication through an efficient route.

Further, as an example for storing the correspondence between the virtual terminal address and the return destination address, in the invention described in claim 2, in the server side data relay device according to claim 1, the virtual terminal address and the return address are returned. It has a server side virtual address correspondence table for storing the correspondence with the destination address,
It is characterized in that the virtual terminal address of the transmission data relayed by the base station data relay device and the return destination address are associated and recorded in the server side virtual address correspondence table.

By doing so, if the correspondence between the virtual terminal address and the return destination address is saved when the transmission data is sent from the mobile terminal, this correspondence is relayed when the reply data is relayed. You can know the return address from the table. In this way, the server side data relay device does not need to separately perform special data communication with the mobile terminal or the base station data relay device to store the corresponding data.

Further, as an example of how to rewrite the transmission data and the reply data, in the invention described in claim 3,
Alternatively, in the server-side data relay device described in 2, a base station data relay device relays a source address part for storing information of a sender and a virtual address part, and the sender address part includes a return destination. When the transmission data addressed to the server whose address is stored and the virtual terminal address is stored in the virtual address part is received, the virtual terminal address is stored in the transmission source address part of this transmission data and sent to the server, When the reply data sent from the server that receives the transmission data and addressed to the virtual terminal address having the destination address part for storing the destination information and the virtual address part is received, the virtual terminal address is set in the virtual address part of the reply data. It is characterized in that it is stored and the return destination address is stored in the destination address part and transmitted.

Further, as a base station data relay device for relaying data in cooperation with the server side data relay device, in the invention according to claim 4, the base station segment to which the base station belongs by wirelessly communicating with the base station. Data transmitted via a wide area network consisting of a plurality of segments between a mobile terminal and a server that are connected to each other and that do not change even if the connection destination base station segment changes In communication, a data relay device that relays data communication between a base station segment and a wide area network, and when the transmission data sent by a mobile terminal for data communication is received, this transmission data is a virtual terminal address. And send it back to the server by rewriting it so that it has a return address that specifies the return destination. The server-side data relay device according to any one of items 1 to 3 relays and reaches the server, and based on this, the server sends the virtual data to the virtual terminal address and the reply data relayed by the server-side data relay device is final. It is characterized in that it reaches the mobile terminal.

As a specific example of the return destination address when the base station data relay device rewrites the transmission data, in the invention described in claim 5, in the base station data relay device according to claim 4, the return address is returned. When the return data relayed by the server-side data relay device according to any one of claims 1 to 3 is received and the return address is used as its own address, the return data is transmitted to the mobile terminal. There is. When the return destination address is its own address and the return data relayed by the server-side data relay device according to any one of claims 1 to 3 is received, the return data is transmitted to the mobile terminal.

As a result, the reply data sent from the server to the virtual terminal address and relayed by the server-side data relay device surely reaches the base station data relay device, and the base station data relay device moves the reply data. Can be sent to the terminal.

Further, as an example for the base station data relay device to store the correspondence between the virtual terminal address of the mobile terminal and the temporary terminal address, in the invention according to claim 6,
In the base station data relay device according to claim 4 or 5, a virtual terminal address of a mobile terminal, which uses one of its own addresses as a temporary terminal address that is an address that can be used while wirelessly communicating with the same base station. It is characterized by having a base station virtual address correspondence table for storing the correspondence with the temporary terminal address.

Such a correspondence table is one of the methods for knowing the temporary terminal address to be delivered from the virtual terminal address which should receive this reply data when this base station data relay device relays the reply data. .

Further, as an example of rewriting the transmission data and the reply data, in the invention described in claim 7, in the base station data relay device according to any one of claims 4 to 6, the mobile station is used for data communication. When receiving the transmission data having the transmission source address portion that stores the transmission source information transmitted from the terminal and the virtual address portion, the return destination address is stored in the transmission source address portion of this transmission data,
It is characterized in that the virtual terminal address is stored in the virtual address portion and is sent to the server.

As a mobile terminal that communicates with a server by relaying the server side data relay device and the base station data relay device, the mobile terminal according to claim 8 is a mobile terminal that communicates with the base station by wireless communication. Even if you connect to the base station segment to which it belongs, perform data communication with the server via the wide area network, and change the temporary terminal address that can be used while wirelessly communicating with the same base station, and the base station segment to connect to A virtual terminal address that does not change is used as its own address, and transmission data for data communication is created so as to have a virtual terminal address and sent out.
Transmission data relayed by the base station data relay device according to any one of claims 4 to 7 and the server-side data relay device according to any one of claims 1 to 3 and reaching the server. Based on the above, the server sends the virtual terminal to the virtual terminal and receives the reply data relayed by the server side data relay apparatus and the base station data relay apparatus.

In such a mobile terminal, a virtual terminal address that does not change even if the base station segment to which it belongs is changed is used as its own address, and the transmission data to be sent to the server has the virtual terminal address. so,
The base station data relay device and the server-side data relay device are relayed to enable uninterrupted communication with the server.

Further, in the invention described in claim 9, the mobile terminal according to claim 8 has a plurality of wireless interfaces for simultaneously connecting to a plurality of base stations by wireless communication, and each wireless interface is different. As the feature of using temporary terminal address,
The mobile terminal may be capable of wireless communication with a plurality of base stations at the same time.

In this case, when the mobile terminal moves to change the base station of the communication destination, it is possible to prevent the interruption of the communication by preparing the connection in advance by using one of the wireless interfaces before the change. You can

The term "interface" used in this specification means a network interface.

Further, as an example for allowing transmission data to include a virtual terminal address in the mobile terminal, in the invention described in claim 10, the mobile terminal described in claim 8 or 9 is used for data communication. It is characterized in that the virtual terminal address is stored in the transmission source address portion of the transmission data to be created, which has the transmission source address portion for storing the transmission source information, and is transmitted.

The address information center according to claim 11, for ensuring data communication when the server first sends a packet to the wireless terminal, that is, when the packet is sent in a form pushed from the server. Is a virtual terminal address that does not change even if the base station segment to which the mobile terminal is connected changes in data communication between the server and the mobile terminal according to any one of claims 8 to 10, and from the server to the virtual terminal. The center virtual address for storing the correspondence between the push destination address, which is the destination to which the server side data relay device sends the communication data, according to any one of claims 1 to 3 which receives the communication data addressed to the address. It has a correspondence table, and when the mobile terminal newly starts wireless communication with the base station, the virtual terminal address of the mobile terminal and the return destination address are Receiving a corresponding notification and less, the correspondence recorded in the center virtual address correspondence table on the basis thereof, is characterized by notifying the corresponding server-side data relay apparatus when needed.

If there is such an address information center, for example, when a packet is sent from a server to a virtual terminal address, the server side data relay device does not have a correspondence between this virtual terminal address and the return destination address. In such a case, by receiving the notification from the address information center, it is possible to obtain this correspondence and enable communication from the server side to the terminal.

In addition, as for data communication when the mobile terminal belongs to the mobile network,
In the invention described in 2, wireless communication with a base station is performed, and the base station of the other party that performs wireless communication based on movement is changed, and a mobile segment that is a segment within itself and the same base station that performs wireless communication with the base station Belongs to and belongs to a mobile network having a mobile radio interface having a self-address as a temporary relay address that can be used during wireless communication, and a mobile data relay device between the mobile radio interface and a mobile segment. In a data communication performed via a wide area network composed of a plurality of segments between a mobile terminal that has one of its addresses as a virtual terminal address that does not change even if the mobile network is changed, and a server, a segment belonging to the server Data that relays data communication between a server-side segment and a wide area network The transmission data, which is a relay device and is transmitted from the mobile terminal for data communication and relayed by the mobile data relay device, has a virtual terminal address and a temporary relay address. Is received and the reply data is sent to the virtual terminal address, the send data information is rewritten and sent, and when the reply data is received, the reply data information is rewritten so that it finally reaches the mobile terminal, and the temporary relay address is sent. The feature is that it is sent to.

As a result, the server side data relay device rewrites the transmission data sent from the mobile terminal and relayed by the mobile data relay device, and the server always sends reply data with the virtual terminal address as the mobile terminal address. Is further rewritten by the server side data relay device,
Since it finally reaches the mobile terminal, even if the mobile terminal changes the connection destination base station, since the server uses the unchanged virtual terminal address for communication, the communication will not be interrupted. Data communication can be reliably performed.

Further, the server side data relay device for rewriting the transmission data and the reply data in this way is between the server side segment and the wide area network, and the mobile data relay device is between the mobile segment and the wide area network. The mobile terminal and the server can perform data communication through an efficient route.

Furthermore, since the server side data relay device records the correspondence between the virtual terminal address of the mobile terminal and the temporary relay address that changes according to the movement of the mobile network in the server side virtual address correspondence table, the movement of the base station network Even if the address of the mobile terminal does not change due to
Since it is possible to follow the change of the connected base station, the communication can be performed without interruption.

As an example for storing the correspondence between the virtual terminal address and the temporary relay address, in the invention described in claim 13, in the server side data device according to claim 12, the virtual terminal address and the temporary relay address are stored. It has a server side virtual address correspondence table for storing the correspondence with addresses, and records in the server side virtual address correspondence table by associating the virtual terminal address of the transmission data relayed by the mobile data relay device with the temporary relay address. It is characterized by doing.

By doing so, if the correspondence between the virtual terminal address and the return destination address is saved when the transmission data is sent from the mobile terminal, this correspondence is relayed when the reply data is relayed. The temporary relay address can be known from the table. In this way, the server side data relay device does not need to separately perform special data communication with the mobile terminal or the base station data relay device to store the corresponding data.

Further, as an example of how to rewrite the transmission data and the reply data, in the invention described in claim 14, in the server side data relay device according to claim 12 or 13, the data is relayed by the mobile data relay device and transmitted. The temporary address is stored in the source address part of the transmission data having the source address part in which the original information is stored and the virtual address part, and the virtual terminal address is stored in the virtual address part. When receiving the send data, the virtual address is stored in the source address part of this send data and sent to the server, and the destination address part that stores the destination information from the server that received the send data,
When the reply data addressed to the virtual terminal address having the virtual address part is received, the virtual terminal address is stored in the virtual address part of the reply data, and the temporary relay address is stored in the destination address part and sent out. .

Further, as a mobile data relay device for relaying data in cooperation with the server side data relay device, in the invention according to the fifteenth aspect, a mobile data relay device is wirelessly communicated with a base station, and a mobile communication partner device performs wireless communication with the base station. A base station is changed to a mobile segment which is a segment within itself, and a mobile radio interface whose own address is a temporary relay address which can be used during radio communication with the base station and radio communication with the same base station. Via a wide area network consisting of a plurality of segments between a mobile terminal that has a virtual terminal address that does not change even if the mobile network to which it belongs changes as one of its own addresses, and a server. In data communication, data that relays data communication between the mobile segment and mobile radio interface The relay device receives the transmission data sent by the mobile terminal for data communication,
The transmission data is rewritten so as to have a virtual terminal address and a temporary relay address and sent to the server, and the transmission data is relayed by the server-side data relay device according to any one of claims 12 to 14. It is characterized in that the reply data relayed by the server-side data relay device and finally sent to the virtual terminal address by this server reaches the mobile terminal.

As a result, the reply data sent from the server to the virtual terminal address and relayed by the server side data relay device surely reaches the mobile data relay device, and the mobile data relay device sends this reply data to the mobile terminal. Can be sent.

Further, as an example for the mobile data relay device to store the correspondence between the virtual terminal address of the mobile terminal and the temporary terminal address, in the invention according to claim 16,
The mobile data relay device according to claim 15, wherein a virtual terminal address and a temporary terminal address of the mobile terminal whose temporary terminal address, which is an address that can be used while belonging to the same mobile network, is one of its own addresses. It is characterized by having a moving virtual address correspondence table for storing correspondence.

Such a correspondence table is one of the methods for knowing the temporary terminal address to be delivered from the virtual terminal address which should receive this reply data when this base station data relay device relays the reply data. .

Further, as an example of how to rewrite the transmission data and the reply data, in the invention described in claim 17, in the mobile data relay device according to claim 15 or 16,
When receiving the transmission data sent from the mobile terminal in the data communication, which has the transmission source address part for storing the transmission source information and the virtual address part, the temporary relay address is stored in the transmission source address part of this transmission data. However, the virtual terminal address is stored in the virtual address portion and sent to the server.

As a mobile terminal that communicates with a server by relaying the server side data relay device and the mobile data relay device, the mobile terminal according to claim 18 wirelessly communicates with a base station and wirelessly communicates based on movement. It is a part that changes the base station of the other party to communicate, and wirelessly communicates with the mobile segment, which is a segment within itself, with the base station, and can be used while wirelessly communicating with the same base station. When belonging to a mobile network having a mobile wireless interface having a relay address as its own address and the mobile data relay device according to any one of claims 15 to 17, data communication is performed with a server via a wide area network, and the same. The temporary terminal address that can be used while belonging to the mobile network and the mobile 18. The base station data relay device according to claim 15, wherein the virtual terminal address is a self-address, and the transmission data for data communication is created and transmitted so as to have the virtual terminal address. And the server-side data relay device according to any one of claims 12 to 14, and the server-side data relay device transmits the data based on the transmission data that reaches the server, and the server-side data relay device and the mobile data relay device It is characterized in that it receives the relayed reply data.

In such a mobile terminal, a virtual terminal address that does not change even if the base station segment connected to the mobile network is changed is used as its own address, and the transmission data to be sent to the server has the virtual terminal address. By doing so, it becomes possible to perform uninterrupted communication with the server by being relayed by the base station data relay device and the server-side data relay device described above.

Further, in the invention described in claim 19, the mobile terminal according to claim 18 has a plurality of wireless interfaces for simultaneously connecting to a plurality of base stations by wireless communication, and each wireless interface is The mobile terminal may be capable of wireless communication with multiple base stations at the same time, as characterized by the use of different temporary terminal addresses.

Further, as an example for allowing transmission data to include a virtual terminal address in the mobile terminal, in the invention described in claim 20, in the mobile terminal described in claim 18 or 19, data transmission is performed. It is characterized in that the virtual terminal address is stored in the transmission source address portion of the transmission data to be created, which has the transmission source address portion for storing the transmission source information, and is transmitted.

The address information center according to claim 21, for ensuring data communication when the server first sends a packet to a wireless terminal, that is, when the packet is sent by being pushed from the server. Is a virtual terminal address that does not change even if the base station segment to which the mobile terminal is connected changes in data communication between the server and the mobile terminal according to any one of claims 18 to 20, and from the server to the virtual terminal. The center virtual address for storing the correspondence between the push-side address, which is the destination to which the server-side data relay device sends the communication data, according to any one of claims 12 to 14, which receives the communication data addressed to the address. It has a correspondence table, the mobile terminal belongs to, wirelessly communicates with the base station, and changes the base station of the other party that wirelessly communicates based on movement. , When a mobile network having a mobile segment, which is its own segment, newly starts wireless communication with a base station, it receives a notification of correspondence between a virtual terminal address of a mobile terminal and a return destination address, and responds based on the notification. The feature is that the correspondence is recorded in the virtual address correspondence table and the correspondence is notified to the server side data relay device when necessary.

With such an address information center, for example, when a packet is sent from a server to a virtual terminal address, the server side data relay device does not have a correspondence between this virtual terminal address and the return destination address. In such a case, by receiving the notification from the address information center, it is possible to obtain this correspondence and enable communication from the server side to the terminal.

Further, in the upper and lower base station data relay apparatus according to the twenty-second aspect, the base station segment to which the base station belongs is connected by wireless communication with the base station, and does not change even if the base station segment of the connection destination is changed. A virtual terminal address is one of its own addresses, and in order to connect to a plurality of base stations, a temporary interface address that can be used while wirelessly communicating with each one base station is used as its own upper and lower wireless interface. In a data communication performed between a mobile terminal having a downlink wireless interface and a server via a wide area network composed of a plurality of segments, a data relay device for relaying the data communication between the upper and lower wireless interfaces and the wide area network. Which is a path for data communication from the mobile terminal to the server When the transmission data sent by the mobile terminal for data communication that makes the line and the downlink, which is the path of data communication from the server to the mobile terminal, different is received, this transmission data is the virtual terminal address and the transmission data. And a sending destination address that specifies a sending destination to the server, and sends the sending data to the server, and the sent sending data is a server side that relays data communication between the server side segment to which the server belongs and the wide area network. Data returned to the server after being relayed by the data relay device and sent to the server based on the transmitted data is the server-side data relay device and the downlink data which is the base station data relay device belonging to the same segment as the downlink wireless interface. The feature is that the base station data relay device relays data to reach the mobile terminal. It is set to.

As described above, the mobile terminal has the two radio interfaces of the upper and lower radio interfaces and the downlink radio interface, and the base station relay device determines the return destination address in the transmission data, so that the uplink and the downlink are surely obtained. Can be performed as different items, and the communication efficiency is improved.

As an example of the return destination address, in the upper and lower base station data relay device according to claim 23, the return destination address is the address of the downlink base station data relay device.

As a result, the reply data sent from the server to the virtual terminal address and relayed by the server side data relay device surely reaches the downlink base station data relay device, and the base station data relay device sends this reply data. It can be sent to mobile terminals.

Further, as an example for the upper and lower base station data relay devices to store the correspondence between the virtual terminal address of the mobile terminal and the temporary terminal address, in the invention of claim 24, in the invention of claim 24, The upper and lower base station data relay devices are characterized by having a base station virtual address correspondence table for storing the correspondence between virtual terminal addresses of mobile terminals and addresses of downlink base station data relay devices.

Further, as an example of rewriting the transmission data and the reply data, in the invention of claim 25,
In the upper and lower base station data relay device according to any one of 2 to 24, transmission data having a transmission source address part for storing information of a transmission source, which is transmitted from a mobile terminal in data communication, and a virtual address part. Is received, the return destination address is stored in the transmission source address part of the transmission data, the virtual terminal address is stored in the virtual address part, and the data is sent to the server.

Further, as a server side data relay device for relaying data in cooperation with the upper and lower base station data relay devices, in the invention of claim 26, the base station to which the base station belongs by wirelessly communicating with the base station. It is performed via a wide area network consisting of a plurality of segments between a mobile terminal that is connected to a segment and has a virtual terminal address that does not change even if the connected base station segment changes and one of its addresses is a server, and a server. In data communication, a data relay device that relays data communication between a server-side segment, which is a segment to which the server belongs, and a wide area network, and an uplink that is a data communication path from a mobile terminal to the server and a server. A mobile terminal for data communication in which the downlink, which is a data communication path to the mobile terminal, is different It is al sent claims 22 25
When the transmission data relayed by the upper and lower base station data relay devices described in any one of 1 to 3 above is received, the server receives the transmission data and rewrites the information of the transmission data so as to transmit the reply data to the virtual terminal address and transmits the data. However, when the reply data is received, the reply data is rewritten and transmitted so that the reply data is relayed by the downlink base station data relay device and reaches the mobile terminal.

The mobile terminal according to claim 27 is a mobile terminal that communicates with a server by relaying the server side data relay apparatus and the upper and lower base station data relay apparatuses.
It connects to a base station by wireless communication and performs data communication with a server via a wide area network, and its own address is a virtual address that does not change even if the connected base station changes, and it is used to connect to multiple base stations. It has a wireless interface and a downlink wireless interface, and these upper and lower wireless interfaces and the downstream wireless interface each have a temporary interface address that can be used during wireless communication with one base station as their own address, and the Created so that the transmission data for data communication that makes the uplink, which is the path of data communication, and the downlink, which is the path of data communication from the server to the mobile terminal, have a virtual terminal address,
The transmission data transmitted from the upper and lower interfaces is relayed by the upper and lower base station data relay device according to any one of claims 22 to 25 and the server side data relay device according to claim 26 and reaches the server. The server is characterized in that the server sends the reply data based on the transmission data and the reply data relayed by the server-side data relay device and the base station data relay device is received from the downlink wireless interface.

As described above, by using a wireless terminal which has an upstream radio interface and a downstream radio interface, and can use the upstream radio interface as an upstream line and the downstream radio interface as a downstream line, the upper and lower lines are different. Communication can be surely performed, which leads to improvement in communication efficiency.

Further, as an example for allowing the transmission data to include the virtual terminal address in the mobile terminal, in the invention described in claim 28, in the mobile terminal in claim 27, it is created and transmitted for data communication. The virtual terminal address is stored in the transmission source address portion of the transmission data having the transmission source address portion having the transmission source information and transmitted.

[0061]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) FIG. 1 shows the overall configuration of a route in data communication performed in the first embodiment of the present invention. Base stations AP1, AP2, ..., APn (hereinafter referred to as APx) to which the mobile terminal 1 connects by wireless communication belong to respective base station segments. The mobile terminal 1 belongs to a base station segment by connecting to the base station APx, and performs data communication with the Internet 2 via this base station segment. This data communication belongs to the same base station segment as the mobile terminal 1 and is located between the base station segment and the Internet.
, BR2, ..., BRn (hereinafter referred to as BRx) are relayed. The server-side segment to which the server 3 belongs is connected to the Internet 2 via the server-side router SR1.

Although IP (Internet Protocol) is used in the Internet 2 and each segment, the mobile terminal 1, the base station BRx, and the server-side router SR1 have VIP (Virtual Inter
Net Protocol) is also supported.

In the VIP, apart from the IP address depending on the base station segment to be connected, a VIP address that does not change after the base station segment to be connected is assigned as an identifier of the mobile terminal 1. The VIP packet, which is the basic unit of communication data in the VIP, has a VIP header part in addition to the IP header part of the IP packet, which is the basic unit of normal communication data, and the VIP address described above is stored in this part. . When the mobile terminal 1 moves the wireless connection partner from one base station segment to another base station segment, its IP address changes, but the VIP address does not change. Therefore, if there is a correspondence between the VIP address and the IP address, that is, the VIP address → IP address can be always resolved, the server 3 can be used in the communication between the mobile terminal 1 and the server 3 on the Internet 2.
Does not lose the identity of the mobile terminal 1 by referring to the VIP address, and can prevent communication interruption.

The VIP-corresponding router located at the relay point between the segments in the Internet 2 plays the role of address resolution. Every time the VIP-compatible router relays or receives the VIP packet transmitted by the mobile terminal 1, it stores the relationship between the IP address and the VIP address included in the VIP packet. After that, when the packet addressed to the VIP address passes through this router, the router delivers the packet addressed to the IP address corresponding to the VIP address, whereby the packet is sent to the correct mobile terminal 1.

However, in the conventional packet delivery technology using VIP, it is necessary for any of the routers on the network to support the VIP.
There is no stipulation as to whether or not P is supported, and depending on the arrangement of the routers that support P, there is the problem that a very detour communication path results, resulting in inefficient communication. Is configured to solve.

Although there are actually a plurality of sets of the server 3, the server-side segment, and the server-side router, it is sufficient to explain the communication between one of them and the mobile terminal 1. Describes only one set of the server 3, the server side segment, and the server side router SR1. Strictly speaking, the base station router BRx and the server-side router SR1 should be expressed as relaying data communication with a segment as a component of the Internet 2, but for simplicity, in this specification, Will be referred to as being relayed to the Internet 2 or connected to the Internet unless otherwise specified.

The mobile terminal 1, as shown by the chain double-dashed line in FIG. 1, performs a connection procedure and the like by radio communication with the base station, and processes and transmits / receives communication data via the terminal radio 11. It comprises a processing unit 12 for performing. The mobile terminal 1 wirelessly connects to a base station APx that is also an access point for data communication, and connects to the Internet 2 via a base station segment that is a segment to which the base station APx belongs. At this time, the mobile terminal 1 is given an IP address by an address allocation procedure generally called DHCP. The IP address is assigned by a host computer called a DHCP server. Here, the base station router BRx also serves as the DHCP server. This IP address is one selected from the IP address space previously assigned to the base station segment,
Since it cannot be used in other segments, if the base station segment to which the mobile terminal 1 wirelessly communicates is changed and the belonging base station segment changes, the IP address assigned also changes.

In addition to the assigned IP address, the mobile terminal 1 has a VIP address unique to the terminal that does not change even if the base station segment to be connected is changed.
The address format of this VIP address is the same as the IP address, and a partial space of the IP address space is used as the VIP address space. The mobile terminal 1 performs data communication by using this VIP address and the above-mentioned IP address as its own address. Here, the VIP of the mobile terminal 1
The address is called a terminal VIP address, and the IP address assigned to the mobile terminal 1 is called a terminal IP address.

When carrying out data communication via the Internet 2, the mobile terminal 1 sends a VIP packet, which is a basic unit of data communication, to the Internet 2. FIG. 2 shows an outline of the structure of this VIP packet and the storage location of the VIP address. The VIP packet has an IP header part having information related to delivery on the network and a data part for storing data to be actually passed, and the IP header part has a sender address for storing the IP address of the sender of the packet. Part, a destination address part that stores the IP address of the destination of the packet, and an option part. Up to this point, the structure is the same as that of an IP packet used in a normal IP, but a VIP part is provided in the option part, which is peculiar to the VIP packet.

A packet having such a structure is recognized as a VIP packet by a network device such as a router supporting VIP, but is recognized as an IP packet by a normal network device supporting only IP. .

In a normal IP, the IP address of the transmission source is stored in the transmission source address section, but here, the mobile terminal 1 is configured to store the terminal VIP address in the transmission source address section and send it out. .

The base station router BRx is located between the base station segment and the Internet 2 and has an interface connected to the base station segment and an interface connected to the Internet 2, whereby the packet relay and the relay are performed between the two. The delivery route can be controlled. The base station router BRx also receives the terminal VIP of the mobile terminal 1 belonging to its own base station segment.
It has a base station VIP correspondence table capable of recording a plurality of correspondences between addresses and terminal IP addresses, and when the mobile terminal 1 connects to this base station router BRx, the terminal VIP address of the mobile terminal 1 And the terminal IP address are recorded and stored in the base station VIP correspondence table, and the correspondence is deleted when the mobile terminal 1 disconnects from the base station router BRx.

The base station router BRx stores the terminal VIP address in the source address part of the packet transmitted from the base station segment to the Internet 2 if
This terminal VIP address is moved to and stored in the VIP portion of the packet, the own IP address is stored in the source address portion, and then the packet is transmitted.

If the terminal VIP address is stored in the VIP portion of the packet addressed to itself from the Internet 2, the IP address corresponding to the terminal VIP address is read from the base station VIP correspondence table, and the IP address is read. The packet is stored in the destination address part and the packet is transmitted to the base station segment.

That is, the base station router BRx has a base station VIP correspondence table creating function and a packet header rewriting function in addition to a normal router function.

The server-side router SR1 is located between the server-side segment and the Internet 2 and has an interface connected to the server-side segment and an interface connected to the Internet 2, whereby the packet relay and The delivery route can be controlled. Also, the server side router SR1
Is a server-side V that can record and store a plurality of sets of correspondence between the terminal VIP address and the return destination address referred to when the packet is relayed from the server 3 to the mobile terminal 1.
It has an IP correspondence table.

This server-side router SR1 sends V packets from the Internet 2 to the server-side segment.
If the VIP address is stored in the IP address section,
I stored in the VIP address and the source address part
The P address is associated with the address, and if the association is not recorded in the server side VIP correspondence table, it is newly recorded. Then, this VIP address is stored in the source address part, and the VIP
The packet is sent after clearing the copy. If the correspondence between the VIP address and another IP address is already recorded in the server side VIP correspondence table, a new correspondence is recorded after deleting the correspondence.

Further, when the same address as the VIP address recorded in the server side VIP correspondence table is stored in the destination address part of the packet transmitted from the server side segment to the Internet 2, the VIP address in the table is stored. The corresponding IP address is stored in the destination address part of the packet, the VIP address is stored in the VIP part, and then the packet is sent out.

That is, the server-side router SR1 has a server-side VIP correspondence table creating function and a packet header rewriting function in addition to a normal router function.

The server 3 is adapted to perform a normal operation in communication with a client such as the mobile terminal 1. In other words, processing is performed based on the received packet to create data to be returned, and the contents stored in the source address part of the received packet are sent to the destination address part, the IP address of the user is sent to the source address part, and then returned. A packet in which data is stored in the data section is transmitted.

Here, regarding the exchange of IP packets between the mobile terminal 1 and the server 3 when the mobile terminal 1 is connected to the base station AP1 by wireless communication, the mobile terminal 1, the base station router BR1 and the server side router will be described. This will be described with reference to FIG. 3 showing changes in the IP header portion of the packet in SR1 and server 3. In the present specification including the drawings, when a specific IP address or VIP address is indicated, its specific value is not described, but is expressed in a symbolic format such as S, TV, B1, W.

The server 3 created by the mobile terminal 1.
In the IP header part of the transmission packet addressed to, the IP address S of the server 3 is stored as the destination address, and the terminal VIP address TV is stored in the transmission source address. As described above, this is a VIP packet when seen from the network equipment that supports VIP, and is an IP packet when seen from the network equipment that only supports IP.

Since all transmission packets addressed to the server transmitted from within the base station segment are relayed by the base station router BR1, this transmission packet is first transmitted to the base station router B.
R1 receives. At this time, the base station router BR1 moves the TV stored in the source address part to the VIP address part and stores it, stores its own IP address B1 in the source address part, and then stores it in the Internet 2. Send out.

This transmission packet looks like a packet from the base station router BR1 to the server 3 when seen from an ordinary router, and is therefore delivered to the server side router SR1 as it is.

The server side router SR1 detects that this transmission packet stores the VIP address in the VIP section, and stores the stored TV and B1 of the transmission source address section.
Is associated with, and if the correspondence is not recorded in the server side VIP correspondence table, it is newly recorded. At this time, if the correspondence between the TV and the IP address other than B1 is recorded in the server side VIP correspondence table, it is deleted.
Then, the TV stored in the VIP section is moved to the transmission source address section and stored therein, and the VIP section is cleared and sent to the server side segment.

At this point, S, which is the IP address of the server 3, is stored in the destination address portion of the transmission packet, and TV, which is the terminal VIP address, is stored in the transmission source address. Therefore, this transmission packet is delivered to the server 3,
The server 3 determines that the transmission source of this transmission packet is the TV, creates a reply packet for the response, and stores TV in the destination address portion of the reply packet and S in the transmission source address portion.

Since the reply packet created in this way is destined outside the server-side segment, it is first received by the server-side router SR1 for relaying. If the TV stored in the destination address part of the reply packet matches one of the VIP addresses recorded in the server side VIP correspondence table, the server side router SR1 determines the server side VI.
IP address corresponding to TV in P correspondence table, that is, B
1 is stored in the destination address part of the reply packet, TV is stored in the VIP part, and then the reply packet is sent to the Internet 2.

Since the destination address of this reply packet is B1, an ordinary router on the Internet 2 delivers this to the base station router BR1.

When the base station router BR1 receiving this reply packet detects that a TV is stored in the VIP section, it reads the terminal IP address T corresponding to this TV from the base station VIP correspondence table, and reads it. It is stored in the destination address part and then this reply packet is sent out in the base station segment. The mobile terminal 1 receives this reply packet, and recognizes that it is from the server 3 because the address S of the server 3 is included in the source address part of the reply packet. By such a packet delivery procedure, the mobile terminal 1 and the server 3 can establish data communication.

Here, the operations of the server side router SR1 and the server 3 viewed from the base station router BR1 will be summarized. As shown in FIG. 3, the packet sent from the base station router BR1 to the server side router SR1 has a set of destination address part: source address part: VIP part of S: B1: T.
The server side router SR1 and the server 3 receiving this packet process the packet, and finally the packet returned from the server side router SR1 to the base station router BR1 is the destination address part. The set of: source address part: VIP part is B1: S: TV.

That is, from the viewpoint of the base station router BR1, the server side router SR1 and the server 3 respectively return the values stored in the destination address part and the source address part of the received packet, as the source address of the packet to be returned. And the destination address part is replaced and stored. The operations of the server-side router SR1 and the server 3 viewed from the base station router will be referred to in the second and third embodiments to be described later for simplification of description.

What is important in the data delivery as described above is that the server 3 recognizes the address of the mobile terminal 1 as the TV which is the terminal VIP address unique to the mobile terminal 1 in this data communication. . Therefore, even if the mobile terminal 1 changes the terminal IP address by changing the base station APx that wirelessly communicates, the server 3 does not need to detect and respond to the change.

In order to see this in detail, the procedure of the handover performed by each network device when the mobile terminal 1 actually connects to the base station AP1 and then moves the connection destination from the base station AP1 to the base station AP2. This will be described below.
FIG. 4 expresses this procedure with a focus on the exchange of signals between the network devices.

First, when the terminal radio 11 of the mobile terminal 1 becomes able to communicate with the base station AP1, the mobile terminal 1 will be able to communicate with the base station AP1.
1 to request the terminal IP address of the terminal to the base station router BR1 which is a DHCP server. The base station router BR1 that has received the request allocates an unused terminal IP address, and notifies the mobile terminal 1 of this together with the IP address of the base station router BR1. As a result, the mobile terminal 1 thereafter uses the assigned IP address as its own address until it moves from the base station AP1 to the base station AP2.

Then, when the mobile terminal 1 notifies the base station router BR1 of its own terminal VIP address, the base station router BR1 which received it notifies the correspondence between the terminal VIP address and the terminal IP address in the base station VIP correspondence table held by the mobile terminal 1. To record. This completes the preparation for starting the connection, and the data communication by VIP is started.

When the transmission packet is first transmitted from the mobile terminal 1 to the server 3, the server side router SR is used as described above.
1 the VIP of the mobile terminal 1 in the server side VIP correspondence table
The correspondence between the address and the IP address of the base station router BR1 is recorded. In this way, data communication is established, and the mobile terminal 1 exchanges data with the server 3.

Thereafter, the mobile terminal 1 moves and the base station AP
1. It is assumed that both the base station AP2 and the base station AP2 enter an available area. The terminal wireless device 11 that has detected this notifies the processing unit 12 of it.

When the processing unit 12 receives the notification, the mobile terminal 1
Requests a new terminal IP address from the DHCP server of the base station router BR2 via the base station AP1 and the base station router BR1. In response to this, the base station router BR2 notifies the mobile terminal 1 of the new terminal IP address together with the IP address of the base station router BR2 via the base station router BR1 and the base station AP1.

Receiving this, the mobile terminal 1 declares to the base station router BR1 to move the connection destination from the base station AP1 to the base station AP2, and based on this, the base station router BR1 declares the wireless connection in the base station VIP correspondence table. The correspondence between the terminal VIP address of the terminal 1 and the terminal IP address is deleted.

After that, the mobile terminal 1 disconnects the radio communication with the base station AP1 and connects with the base station AP2. At that time, the base station router BR2 records the correspondence between the terminal VIP address and the new terminal IP address in the base station VIP correspondence table. At the same time, the mobile terminal 1 is connected to the server side router SR1.
Notifies that the base station AP2 is used, and the server side V
The correspondence between the previous IP address and the VIP may be deleted from the IP correspondence table, the correspondence between the new IP address and the VIP may be recorded, or the transmission packet may be transmitted to the mobile terminal 1 later for communication with the server S. Server router S by sending
R1 may be made to rewrite the server side VIP correspondence table as described above.

By doing so, when the mobile terminal 1 changes the base station APx for wireless communication and moves the connected base station segment, the base station router BRx and the server side router SR1 rewrite their respective VIP correspondence tables. Therefore, the server 3 can always identify the mobile terminal 1 by using the VIP address unique to the mobile terminal 1, and the communication between the two is not interrupted even when the mobile terminal 1 moves.

Further, the routers corresponding to VIP and having the VIP correspondence table are the base station router BRx and the server side router SR.
Since I only need to have 1 and VI
Installation is easy because there is no need to install a P-compatible router.

Further, since the routers corresponding to the VIP and having the VIP correspondence table are always in the base station router BRx and the server side router SR1 and the packet can always pass through the efficient route, the router corresponding to the VIP. The problem that the packet is largely detoured depending on the arrangement of is solved.

(Second Embodiment) FIG. 5 shows the overall structure of a path in data communication performed in the second embodiment of the present invention. In the present embodiment, the mobile terminal 1 wirelessly communicates with the base station BRx and communicates wirelessly based on movement.
When belonging to the mobile network 4 that changes Rx,
Data communication between the mobile terminal 1 and the server 3 will be described.

Although IP is used in the Internet 2 and each segment, the mobile terminal 1, mobile router CR, and server-side router SR1 also support VIP.

A characteristic of this embodiment is that even if the mobile network 4 moves and the base station of the other party for wireless communication changes, the IP address of the device belonging to the mobile network 4 does not change. That is. Therefore, since the mobile terminal 1 always has the same IP address, the conventional agent such as VIP or mobileIP cannot confirm the delivery route even if the home agent or the router knows the IP address of the mobile terminal 1, and as a result, communication of It will cause a disruption. As described in detail below, in this embodiment, the mobile router CR included in the mobile network 4 is set to VI.
This problem is solved by supporting P.

In this embodiment, the mobile terminal 1, the base station APx, the Internet 2, the server side router SR1 and the server 3 are the same in configuration and operation as in the first embodiment. Here, detailed description regarding them is omitted. Further, the base station router BRx does not need to support VIP as in the first embodiment, and the base station router BRx is an ordinary router and DHC.
Act as a P server.

The mobile network 4 shown by the chain double-dashed line in FIG. 5 is connected to the base station APx by wireless communication, and a mobile network radio WD to which an IP address is given from the base station router BRx at each connection. A mobile segment 42 which is a segment in the mobile network, a mobile terminal 1 which belongs to this mobile segment 42, a mobile router CR which relays data communication between the mobile network radio WD and the mobile segment 42. Consists of. The mobile router CR also serves as a DHCP server for the mobile terminal 1.

An example of the mobile network 4 is a train,
A network laid in a transportation means such as an airplane, a bus, and a ship can be considered. A person boarding these means connects the mobile terminal 1 or a fixed terminal such as a computer or an electronic device to the mobile segment 42, and the mobile network radio WD
By changing the base station that wirelessly communicates each time it moves, it can continue to be connected to a wide area network such as the Internet 2. It should be noted that the present embodiment describes the case where the mobile terminal 1 having the VIP address connects to the mobile network 4, and therefore the fixed terminal connected to the mobile segment 42 will not be mentioned.

Further, the mobile segment 42 is assigned a unique IP address space which is not dependent on the base station APx with which the mobile network radio WD communicates wirelessly, and serves as an interface connecting the mobile router CR and the mobile segment 42. Is allocated from this IP address space.

Mobile terminal 1 belonging to this mobile segment
Is assigned one from this address space by DHCP.

Further, the mobile router CR uses the mobile segment 4
2 has a mobile VIP correspondence table capable of recording a plurality of correspondences between the terminal VIP address and the terminal IP address of the mobile terminal 1 belonging to No. 2, and when the mobile terminal 1 belongs to the mobile segment 42, the mobile VIP 1 The correspondence between the terminal VIP address of the terminal 1 and the terminal IP address is recorded in the mobile VIP correspondence table, and the correspondence is deleted when the mobile terminal 1 leaves the moving segment 42.

Also, if the VIP address is stored in the source address part of the packet to be transmitted from the mobile network 4 to the Internet 2 via the base station segment, the mobile router CR uses this VIP address as the VIP part of the packet. The wireless network IP address, which is the IP address of the mobile network wireless system WD, is stored in the transmission source address section, and then the packet is transmitted.

[0114] In addition, V packets are sent to the VIP part of the packet addressed to itself from the Internet 2 via the base station segment.
If the IP address is stored, the VIP address is stored in the destination address part and the packet is sent to the moving segment.

Here, the mobile network 4 to which the mobile terminal 1 belongs is connected to the base station AP1 by the mobile network radio WD.
6 shows a change in the IP header portion of the packet in the mobile terminal 1, the mobile router CR, the server-side router SR1, and the server 3 regarding the exchange of IP packets between the mobile terminal 1 and the server 3 when connected to the mobile terminal 1. Explained by. However, the operations and IP addresses and VIP addresses of the mobile terminal 1, the server 3 and the server-side router SR1 are equivalent to those in the above-described first embodiment, and detailed description thereof will be omitted.

S is stored in the destination address portion of the transmission packet sent from the mobile terminal 1 to the server 3, and TV is stored in the transmission source address portion. The mobile router CR receives this, stores the TV in the VIP part, stores the wireless device IP address W of the mobile network wireless device WD in the source address part, and sends it to the connected base station segment. In this embodiment, since the base station router BR1 does not support VIP, it may be regarded as the same as a normal router on the Internet 2.

This transmission packet is sent to the server side router SR1.
Is sent to the server 3 through the server 3, a reply packet is created by the server 3, and the mobile router CR is sent via the server side router SR1.
Will be returned to. At this time, as described in the first embodiment, the destination address part and the source address part of the returned packet are obtained by exchanging the destination address part and the source address part of the sent packet. That is, the destination address part: source address part: VIP part of the packet returned to the mobile router CR is W: S: TV, respectively.

Upon receipt of this, the mobile router CR receives the VI
Detecting that the TV is stored in the P section, read T, which is the IP address corresponding to this TV, from the own mobile VIP correspondence table, store this in the destination address section, and then move this packet. Send to segment 42. The mobile terminal 1 receives this packet and recognizes that this packet is from the server 3 because the address S of the server 3 is included in the source address part of the packet. By such a packet delivery procedure, the mobile terminal 1 and the server 3 can establish data communication.

In the data delivery as described above, in addition to the fact that the server 3 recognizes the address of the mobile terminal 1 as TV which is the terminal VIP address unique to the mobile terminal 1 in this data communication, It is important that the reply packet returned from the server-side router SR1 is addressed to the wireless device IP address W. This W
Changes according to the change of the base station segment to which the mobile network 4 is connected. Therefore, by sending a packet to this W, the server side router SR1 follows the movement of the mobile network and avoids communication interruption. Is possible.

To see this in detail, the mobile network 4 connects to the base station AP1 and then to the base station AP1.
The procedure of the handover performed in each network device when moving from the base station to the base station AP2 will be described below. FIG. 7 shows this procedure with a focus on the exchange of signals between the network devices.

First, when the mobile network radio WD of the mobile network 4 becomes able to communicate with the base station AP1, the mobile network radio WD notifies the mobile router CR of this, and the mobile router CR which receives it notifies the base station AP1. To the base station router BR1 which is a DHCP server via the mobile network radio WD
Request the wireless device IP address. The base station router BR1 that has received the request allocates an unused IP address and notifies the mobile router CR of this together with the IP address of the base station router BR1. Accordingly, the mobile network radio WD thereafter uses the assigned IP address as its own address until the mobile network 4 moves from the base station AP1 to the base station AP2.

Then, when the mobile terminal 1 notifies its own VIP address to the mobile router CR, the mobile router CR which has received the notification records the correspondence between T and TV in the mobile VIP correspondence table held therein. This completes the preparation for connection start,
Data communication by VIP is started.

When a packet is first sent from the mobile terminal 1 to the server 3, the server side router SR1 shows the correspondence between the VIP address of the mobile terminal 1 and the IP address of the mobile network radio WD in the server side VIP correspondence table. Record.
In this way, data communication is established, and the mobile terminal 1 exchanges data with the server 3.

After that, the mobile network radio WD, which has detected that the mobile network 4 has moved and entered the area where both the base stations AP1 and AP2 can be used, notifies the mobile router CR of it.

The mobile router CR that has received the notification is
P1, base station router BR1 through base station router BR1
Request the new radio IP address of the mobile network radio WD. In response, the base station router BR2 notifies the mobile router CR of the new radio IP address together with the IP address of the base station router BR2 via the base station router BR1 and the base station AP1.

After this, the mobile network radio WD determines that the base station A
The wireless communication with P1 is disconnected and the base station AP2 is connected.
At this time, the mobile terminal 1 is connected to the server side router SR1 by the base station A.
Notifying that P2 is used, deleting the correspondence between the previous radio IP address of the mobile network radio WD and the terminal VIP address of the mobile terminal 1 from the server-side VIP correspondence table, new radio IP address and terminal VIP The correspondence with the address may be recorded, or the mobile terminal 1 may later send a packet for communicating with the server S to cause the server-side router SR1 to rewrite the correspondence table as described above. Good.

By doing so, the server side router SR1 rewrites the server side VIP correspondence table when the mobile network 4 changes the base station APx for wireless communication, so that the server 3 has a terminal VIP address unique to the mobile terminal 1. The mobile terminal 1 can always be identified by using.

Further, since it is sufficient for the mobile router CR and the server-side router SR1 to have routers corresponding to VIP and having a VIP correspondence table, it is not necessary to install VIP-compatible routers at various points of the relay point. Easy to introduce.

Further, the router corresponding to VIP and having the VIP correspondence table is always mobile router CR and server side router SR.
1 and the packet can always pass through an efficient route, the problem that the packet is largely detoured depending on the arrangement of the router corresponding to VIP is solved. Furthermore, the server-side router SR1 is a mobile terminal. V of 1
Since the correspondence between the IP address and the radio IP address of the mobile network radio WD that changes depending on the movement of the mobile network 4 is recorded in the server side VIP correspondence table, connection is possible even if the IP address of the mobile terminal 1 does not change. Since the movement of the place can be followed, the communication is not interrupted.

(Third Embodiment) FIG. 8 shows the overall structure of a route in data communication performed in the third embodiment of the present invention. In the present embodiment, a case will be described in which the mobile terminal 1 has two wireless interfaces to which different IP addresses are assigned, and these two wireless interfaces can be used for the uplink and the downlink, respectively. However, the description of the portions equivalent to those of the above-described first embodiment will be omitted or will be simplified.

The base stations of the present embodiment are capable of performing high-speed data communication covering a relatively narrow area and are capable of high-speed data communication APN11, APN12, ..., APN1n, APN2.
, APN22, ..., APN2n, ... (hereinafter referred to as APNx), and base stations APW1, APW2 ,.
Wx). A plurality of base stations APNx in the proximity area belong to the same segment and have the same base station routers BRN1, BRN2, ..., BRNn (hereinafter, BRNn).
connected to the Internet 2 via (x).
In addition, the base station APWx is a base station router BRW.
, BRW2, ..., BRWn (hereinafter referred to as BRWx) are connected to the Internet 2. in this way,
The base station APNx and the base station APWx do not belong to the same segment.

The mobile terminal 1 has a downlink radio set TDN that can be used only for downlinks and an uplink radio set TDW that can be used for uplinks and downlinks. Downlink radio TDN is a base station AP
Only the Nx can be communicated with, and the upstream radio T
The DW can communicate only with the base station APWx.

The down radio TDN and the up radio TD
W is a base station APNx and a base station APW by wireless communication.
When connected to x, the respective IP addresses are given from the base station router BRNx and the base station router BRWx. The mobile terminal 1 has one terminal VIP address as its own address, which does not change even when the base station segment to be connected is moved.

The base station router BRNx is the VI of the mobile terminal 1.
There is a base station VIP correspondence table capable of recording a plurality of sets of correspondence between the terminal VIP address which is the P address and the IP address of the connected downlink radio device TDN, and the downlink radio device TDN has this correspondence table. When connecting to the router BRNx, the correspondence between the above-mentioned terminal VIP address and IP address is recorded in the base station VIP correspondence table, and this correspondence is deleted when the mobile terminal 1 disconnects from this base station router BRNx. It is like this. Further, the base station router BRNx has a packet header replacement function similar to that of the base station router BRx of the first embodiment described above, and D
Also serves as an HCP server.

On the other hand, the base station router BRWx has a plurality of correspondences between the IP address of the base station router BRNx to which the downlink radio device TDN is connected, the IP address of the uplink radio device TDW to which it is connected, and the terminal VIP address. It has a base station VIP correspondence table that can record pairs, and when the upstream radio TDW connects to this base station router BRWx,
The correspondence between the above VIP address and two IP addresses is recorded in the base station VIP correspondence table, and when the mobile terminal 1 disconnects from this base station router BRWx, this correspondence is deleted.

This base station router BRWx moves the terminal VIP address to the VIP part of the packet and stores it if the terminal VIP address is stored in the source address part of the packet sent from the base station segment to the Internet 2. In the source address section, the IP address of the base station router BRNx to which the downlink radio device TDN is connected is stored, and then the packet is transmitted.

If the VIP address of the packet addressed to itself from the Internet 2 is stored, the IP address of the upstream radio TDW of the mobile terminal 1 having the VIP address is stored in the destination address part. To send packets. The base station router BRWx also serves as a DHCP server.

The server 3 and the server-side router SR
Since No. 1 has the same configuration and operation as those of the first embodiment, a description thereof will be omitted here.

Here, the downlink radio unit TDN is the base station APN.
11. When the up radio TDW is connected to the base station APW1, the radio terminal 1 goes down to the down radio TD.
N, regarding packet exchange when communicating with the server 3 using the uplink radio TDW for the uplink, the mobile terminal 1, the base station router BRW1, the base station router BRN1, the server side router SR1, the packet IP in the server 3
This will be described with reference to FIG. 9 showing changes in the header section.

First, the mobile terminal 1 sends a transmission packet, which is a packet addressed to the server 3, to the base station router BRW1 through the upstream radio TDW. S, which is the IP address of the server 3, is stored in the destination address portion of this transmission packet, and TV, which is the terminal VIP address of the mobile terminal 1, is stored in the transmission source address portion.

The base station router BRW1 receiving this transmission packet stores the TV in the VIP section, and the transmission source address section stores BN1 which is the IP address of the base station router BRN1 connected to the base station APN11. To do. As described above, the source address part of the packet sent from the base station router BRW1 is not the IP address BW1 of the base station router BRW1 but the IP address BN1 of the base station router BRN1 to which the downlink radio device TDN is connected. This is a characteristic part.

The transmission packet thus transmitted to the Internet 2 reaches the server 3 via the server side router SR1, and the reply packet created and transmitted by the server 3 based on this packet is transmitted via the server side router SR1. Although transmitted to the Internet 2, the values stored in the destination address part and the source address part are exchanged in the header part of the reply packet returned as shown in the first embodiment. Therefore, the BN1 stored in the source address part of the transmitted transmission packet is stored in the destination part of the returned reply packet. Therefore, this reply packet is delivered to the base station router BRN1.

Base station router B receiving this reply packet
When the RN1 detects that the TV is stored in the VIP section, it reads the TN that is the IP address corresponding to this TV from the base station VIP correspondence table that it has, stores it in the destination address section, and then returns this reply. Send the packet into the base station segment. The mobile terminal 1 receives this reply packet and recognizes that this reply packet is from the server 3 because the address S of the server 3 is included in the source address part. By such a packet delivery procedure, the mobile terminal 1 and the server 3 can establish data communication in different uplinks and downlinks.

Even in the data delivery as described above,
In this data communication, the server 3 recognizes the address of the mobile terminal 1 as TV which is a VIP address unique to the mobile terminal 1. Therefore, by changing the base stations APNx and APWx with which the mobile terminal 1 wirelessly communicates, the IP
Even if the address is changed, the server 3 does not have to detect and respond to that.

In order to see these things in detail, the mobile terminal 1 is actually connected to the base stations APW1 and APN1, and then the downlink radio unit TDN is connected to the base station APN11.
The procedure of the handover performed in each network device when moving from the base station to the base station APN21 will be described below. FIG. 10 shows this procedure with a focus on the exchange of signals between the network devices.

First, when the upstream radio TDW of the mobile terminal 1 becomes communicable with the base station APW1, the mobile terminal 1 via the base station APW1 is a base station router B which is a DHCP server.
Request the IP address of the upstream radio TDW from RW1.
The base station router BRW1 that received the request allocates an unused IP address and assigns it to the base station router BRW1.
The mobile terminal 1 is notified together with the IP address. As a result, the upstream radio TDW thereafter uses the assigned IP address as its own address.

Next, the downlink radio unit TDN is connected to the base station APN1.
1, the mobile terminal 1 requests the IP address of the downlink radio device TDN from the base station router BRN1 which is a DHCP server via the base station router BRW1 already connected. The base station router BRN1 that has received the request allocates an unused IP address and assigns it to the base station router BRW together with the IP address of the base station router BRN1.
1 to the mobile terminal 1. As a result, the downstream radio apparatus TDN thereafter uses the assigned IP address as its own address until it moves from the base station APN11 to the base station APN21.

Then, when the IP address is given to the downlink radio device TDN, the mobile terminal 1 notifies the base station router BRW1 via the uplink radio device TDW, and the base station VIP
To the correspondence table, the terminal VIP address of the mobile terminal 1, the IP address of the base station router BRN1, and the I of the upstream radio TDW.
The correspondence between the P address and is recorded. Further, the base station router BRN1 is notified via the base station router BRW1 to record the correspondence between the terminal VIP address of the mobile terminal 1 and the IP address of the downlink radio TDN in the base station VIP correspondence table. After that, the downlink radio TDN is connected to the base station APN11.
It becomes possible to perform data communication by connecting to and using this for the downlink.

When the packet is first sent from the mobile terminal 1 to the server 3, the server VIP correspondence table in the server side router SR1 indicates the terminal VIP address of the mobile terminal 1 and the IP address of the base station router BRN1 as described above. Record the correspondence. In this way, data communication is established, and the mobile terminal 1 exchanges data with the server 3 by using the base station APW1 for the uplink and the base station APN11 for the downlink.

Thereafter, the mobile terminal 1 moves and the base station AP
It is assumed that W1 has entered the area where both the base station APN11 and the base station APN21 can be used while continuing to be used. The downlink wireless device TDN which has detected this notifies the processing unit 12 of it.

When the processing unit 12 receives the notification, the mobile terminal 1
Requests the IP address of the new downlink radio TDN from the DHCP server of the base station router BRN2 via the base station APW1 and the base station router BRW1. In response to this, the base station router BRN2 is connected to the base station router BRN1 and the base station APN.
11 to the mobile terminal 1 via the new downlink radio TDN I
The mobile terminal 1 which notifies the P address together with the IP address of the base station router BRN2
The connection destination from the base station APN11 to the base station A via the RW1
Declaring to move to PN21, the base station router BRW1 is made to record the correspondence between the VIP address of the mobile terminal 1 and the IP address of the base station router BRN2 in the base station VIP correspondence table, and the base station router BRN2 is made to correspond to the base station VIP. The correspondence between the VIP address of the mobile terminal 1 and the IP address of the downlink wireless device TDN is recorded in the correspondence table, and the VIP address of the mobile terminal 1 and the IP address of the downlink wireless device TDN in the base station VIP correspondence table are recorded in the base station router BRN1. Delete the correspondence with.

After that, the downlink radio unit TDN receives the base station APN.
The wireless communication with 11 is disconnected, and the base station APN21 is connected. In this way, the mobile terminal 1 is connected to the base station A on the uplink.
It becomes possible to exchange data with the server 3 by newly using the base station APN21 for the downlink of the PW1.

At this time, the mobile terminal 1 sends a packet to communicate with the server S, so that the server side router SR
1 is the deletion of the correspondence between the previous terminal VIP address of the mobile terminal 1 and the IP address of the base station router BRN1 from the server side VIP correspondence table, and the correspondence between the terminal VIP address of the mobile terminal 1 and the IP address of the base station router BRN2. Make a record.

Therefore, even when the uplink and the downlink are separated as described above, the base station router BR
There is no need for Wx and the server-side router SR1 to perform special negotiation for that purpose.

As described above, in the case where the wireless terminal has two wireless devices and the base stations wirelessly communicating with each other are different types of base stations capable of performing data communication at different speeds, etc. Hybrid communication is the use of different lines for these radios.

In such hybrid communication, assigning a relatively high-speed communication line to the downlink as in the present embodiment is generally performed in the mobile terminal 1 where the downlink has a larger data transfer amount than the uplink. , Helps to improve the efficiency of data delivery. Further, by specializing the downlink radio device TDN used for the high speed line only for the downlink line, it is possible to suppress the power consumption for the output of the antenna.

As a similar hybrid communication system, for example, as a prior art, Japanese Patent Laid-Open No. 12-31617 is used.
Although there is JP-A-8, this requires that the lines to which the two radios are connected be connected to one gateway, but this is not necessary in the configuration of the present embodiment.

In the present embodiment, the downlink has been described mainly using the downlink radio TDN, but the uplink and downlink may also use the uplink radio TDW. For example, when the downlink radio device TDN cannot be used, the radio terminal 1 has the downlink radio device TDN as the only mobile radio device 11, that is, the same operation as that of the above-described first embodiment is performed. Uplink radio TD
W is shared by the upper and lower lines.

Further, as the same effect as that of the first embodiment,
Base station APNx or base station AP with which the mobile terminal 1 wirelessly communicates
When Wx is changed, the base station router BRNx, the base station router BRWx, and the server side router SR1 have their respective VIs changed.
Since the P correspondence table is rewritten, the server 3 can always identify the mobile terminal 1 by using the terminal VIP address unique to the mobile terminal 1, and the communication between the two is not interrupted even when the mobile terminal 1 moves.

Further, routers corresponding to VIP and having a VIP correspondence table are base station router BRNx and base station router B.
Since only the RWx and the server-side router SR1 are required, it is not necessary to install the VIP-compatible router at various places of the relay point, which facilitates the introduction.

Further, the routers corresponding to the VIP and having the VIP correspondence table are always in the base station router BRNx, the base station router BRWx, and the server side router SR1, and the packet can always pass through the efficient route. So VI
A router corresponding to P is installed in a location where the route is inefficient, and problems such as large detours of packets and undeliverable packets are solved. (Fourth Embodiment) In the above-described first to third embodiments, the case where there is a transmission packet from the wireless terminal 1 to the server 3 first and then the server 3 returns a reply packet to the wireless terminal 1 has been described. It was In the present embodiment, a configuration based on the first embodiment is used not in such a case but in the case where the server 3 first sends the packet to the wireless terminal 1, that is, the case where the server 3 sends the packet in a push mode. This will be explained as an example.

A schematic diagram of the network used in this case is shown in FIG. The difference between FIG. 1 shown in the first embodiment and FIG. 11 is that the VIP center 5 is connected to the Internet 2. This VIP center 5 has a center VIP correspondence table, and describes the correspondence between the VIP address of the mobile terminal 1 and the base station router BRx to which the mobile terminal 1 is connected as the push destination IP address.

The description in the center VIP correspondence table is performed when the correspondence between the VIP address and the IP address changes when the mobile terminal 1 newly starts data communication or moves the base station APx. Be seen. The request for rewriting the center VIP correspondence table to the VIP center 5 is made by the mobile terminal 1 or the base station router BRx, and accordingly, the VIP center 5 rewrites the center VIP correspondence table.

When the server 3 tries to send a packet to the VIP address of the mobile terminal 1, the server side router S
R1 has this VIP in its own center VIP correspondence table
If there is no entry corresponding to the address, the VIP center 5 is inquired to know the corresponding IP address. This inquiry may be made only once, and thereafter, the known correspondence may be recorded in the own VIP correspondence table on the server side and referred to, or when the packet is pushed from the server 3, the server side router SR1. May periodically make inquiries to the VIP center 5.

Further, before the server 3 pushes a packet, every time the center VIP correspondence table of the VIP center 5 is rewritten, the VIP center 5 sends a packet to the server side router S.
The VIP rewriting request may be transmitted to R1, and the server side router SR1 may rewrite the center VIP correspondence table owned by the server router SR1 in response to the request.

[0166] The VIP address and I
According to the correspondence with the P address, the server side router SR1 stores the VIP address in the VIP part of the packet and the IP address corresponding to the destination address part and sends the packet to the Internet 2.

V connecting to the Internet 2 in this way
The IP center 5 has a center VIP correspondence table, and each time the mobile terminal 1 connects to a new base station, this center VIP correspondence table is displayed.
By rewriting the correspondence table so that the server side router SR1 knows the information as necessary, it becomes possible to transmit the packet from the server 3 to the mobile terminal 1 first.

The center V of the VIP center
The IP address of the mobile terminal 1 may be associated with the VIP address of the mobile terminal 1 in the IP correspondence table.

Further, although the case where the VIP center 5 is provided in the configuration of the first embodiment has been described in the present embodiment, the case where the VIP center 5 connected to the Internet is provided in the configurations of the second and third embodiments is also described. , You can get exactly the same effect. However, V
In the center VIP correspondence table of the IP center, the correspondence with the VIP address of the mobile terminal 1 is the IP address of the mobile network radio WD of the mobile network 4 in the second embodiment, and the downlink in the third embodiment. Base station router BRNx connected to the radio TDN
IP address of the base station router BRWx connected to the upstream radio TDW, the IP of the downstream radio TDN
It is either the address or the IP address of the upstream radio TDW.

In these first to fourth embodiments, the Internet 2 is a wide area network, the server side router SR1 is a server side data relay device, and I
The P address is an address, the VIP address is a virtual address, the terminal VIP address is a virtual terminal address, the terminal IP address is a temporary terminal address,
The VIP part is a virtual address part, the base station VIP correspondence table is a base station virtual address correspondence table, the server side VIP correspondence table is a server side virtual address correspondence table, a transmission packet is transmission data, and a reply packet is It is reply data, and the terminal wireless device 11 is a wireless interface.

Also, in the first embodiment, the base station router BRx is a base station data relay device.

In the second embodiment, the mobile router CRx is the mobile data relay device, the mobile network radio WD is the mobile radio interface, and the radio IP.
The address is a temporary relay address, the mobile VIP correspondence table is the base station virtual address correspondence table, and the base station router BR
x is a data relay device.

In the third embodiment, the base station router BRWx is the upper / lower base station data relay device, and the base station router BRNx is the downstream base station data relay device.
The IP address of the downlink radio device TDN and the IP address of the uplink radio device TDW are temporary interface addresses, the uplink radio device TDW is a vertical radio interface, and the downlink radio device TDN is a downlink radio interface.

Also, in the fourth embodiment, the base station router BRx is a base station data relay device, the push destination IP address is the push destination address, and the center V
The IP correspondence table is a center virtual address correspondence table. (Other Embodiments) In the first to fourth embodiments, a router is used as the data relay device, but any device having a router function may be used, for example, a gateway.

The terminal VIP address of the mobile terminal 1 is assumed to be unique to the terminal, but it is sufficient if the base station segment to which the mobile terminal 1 belongs while data communication is unchanged. For example, it may be an IP address given by DHCP when starting data communication and invalidated when terminating the connection after ending data communication. In this way, the number of VIP addresses required is the number of mobile terminals that perform data communication at the same time, which leads to saving of VIP addresses as compared with the case where VIP addresses are given to all mobile terminals that perform data communication. . This is particularly useful when there is a concern that the address space will be exhausted, such as when using IPv4.

Further, the base station router, the server side router, and the mobile router are supposed to have a virtual address correspondence table.
It is also possible to store the virtual address correspondence table in another host and refer to it when necessary. Also, although these routers also serve as DHCP servers, D
An HCP server may be provided.

Although the wide area network is the Internet 2, this is not necessarily the Internet 2 and may be any data communication network as a group of segments.

The base station router BRx in the first embodiment is the mobile router CR in the second embodiment.
However, in the third embodiment, the base station router BRNx is
Although the destination address of the reply packet is the IP address, it does not necessarily have to be the IP address.
It may be the terminal VIP address of the mobile terminal 1. That is, the segment to which the mobile terminal 1 belongs is configured so that the mobile terminal 1 can receive the reply packet based on the identifier that identifies the mobile terminal 1 to which the reply packet should finally return. It is all right.

Further, in the first embodiment, the server side V
The return address recorded in the IP correspondence table in correspondence with the terminal VIP was the IP address of the base station router BRx.
This may be the terminal IP address of the mobile terminal 1. Further, in the third embodiment, the IP address of the base station router BNx is recorded in the server-side VIP correspondence table, but this may be the IP address of the downlink wireless device TDN of the mobile terminal 1. By doing so, it becomes unnecessary to change the contents of the header of the reply packet at the base station BRx and the base station BRNx, respectively.

Further, in the first, second and fourth embodiments, the mobile terminal has one wireless interface, but it may have a plurality of wireless interfaces. In that case, an IP address is given to each interface, that is, the mobile terminal 1 has a plurality of terminal IP addresses. By doing so, when the base station segment to which it belongs is moved, the handover can be smoothly performed by connecting to the new base station segment by another radio interface before disconnecting the connection of one radio interface. You can

Further, in the third embodiment, the mobile terminal 1
Has two interfaces, but it has three or more interfaces, and packets may be allocated to each to communicate.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a network according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a structure of a VIP packet.

FIG. 3 is a diagram illustrating a mobile terminal 1 and a server SR according to the first embodiment.
It is a figure of the flow of the communication packet of 1.

FIG. 4 is a diagram showing exchange of signals when the mobile terminal 1 moves through a base station APx.

FIG. 5 is a diagram showing an overall configuration of a network according to a second embodiment.

FIG. 6 is a diagram showing a mobile terminal 1 and a server SR according to the second embodiment.
It is a figure of the flow of the communication packet of 1.

FIG. 7 is a diagram showing exchange of signals when the mobile network 4 moves a base station APx.

FIG. 8 is a diagram showing an overall configuration of a network according to a third embodiment.

FIG. 9 is a mobile terminal 1 and a server SR according to the third embodiment.
It is a figure of the flow of the communication packet of 1.

FIG. 10 is a diagram showing exchange of signals when the downlink radio device TDN moves through a base station APNx.

FIG. 11 is a diagram showing an overall configuration of a network according to a fourth embodiment.

[Explanation of symbols]

1 ... Mobile terminal, 2 ... Internet, 3 ... Server, 4 ...
Mobile network, 5 ... VIP center, 11 ... Terminal radio, 12 ... Processing unit, 42 ... Mobile segment.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5K030 GA12 HA11 HC01 HD03 HD09                       JA05 JL01 JT09 KA15 LB05                 5K033 AA05 CB09 CC01 DA06 EC03

Claims (28)

[Claims] 1. A mobile device that connects to a base station segment to which the base station belongs by wirelessly communicating with the base station and uses as one of its own addresses a virtual terminal address that does not change even if the connected base station segment is changed. In data communication performed between a terminal and a server via a wide area network composed of a plurality of segments, data for relaying the data communication between a server side segment which is a segment to which the server belongs and the wide area network A relay device, which is sent from the mobile terminal for the data communication, is relayed by a base station data relay device between the base station segment and the wide area network, and has the virtual terminal address and a return destination. When the server receives the transmission data with the specified return address, the server receives it. Then, the information of the transmission data is rewritten and transmitted so that the reply data is transmitted to the virtual terminal address, and when the reply data is received, the information of the reply data is rewritten so that it finally reaches the mobile terminal. Server-side data relay device for sending to the return destination address. 2. The virtual terminal having a server side virtual address correspondence table for storing the correspondence between the virtual terminal address and the return destination address, and the virtual terminal included in the transmission data relayed by the base station data relay device. The server-side data relay device according to claim 1, wherein an address and the return destination address are associated and recorded in the server-side virtual address correspondence table. 3. A base address data relay device relays a source address part for storing information of a source and a virtual address part, and the source address part stores the return destination address. When the transmission data addressed to the server in which the virtual terminal address is stored in the virtual address portion is received, the virtual terminal address is stored in the source address portion of the transmission data and sent to the server. Sent out, sent from the server that received the transmission data,
When receiving the reply data addressed to the virtual terminal address having a destination address part storing destination information and a virtual address part, the virtual terminal address is stored in the virtual address part of the reply data, and the destination address is stored. The server-side data relay device according to claim 1 or 2, wherein the return destination address is stored in a unit and transmitted. 4. A move which connects to a base station segment to which the base station belongs by wirelessly communicating with the base station, and uses as one of its own addresses a virtual terminal address which does not change even if the connected base station segment is changed. A data relay device that relays the data communication between the base station segment and the wide area network in the data communication performed between the terminal and the server via the wide area network including a plurality of segments. Then, when the transmission data sent by the mobile terminal for the data communication is received, the transmission data is rewritten so as to have the virtual terminal address and the return destination address designating the return destination, and is transmitted to the server. The transmission data is relayed by the server-side data relay device according to any one of claims 1 to 3. The base is characterized in that the reply data relayed by the server-side data relay device, which reaches the server and is sent to the virtual terminal address by the server, finally reaches the mobile terminal. Station data relay equipment. 5. When the return destination address is used as its own address, and the return data relayed by the server-side data relay device according to any one of claims 1 to 3 is received, the return data is transferred to the mobile device. The base station data relay device according to claim 4, which transmits to a terminal. 6. Correspondence between the virtual terminal address of the mobile terminal and the temporary terminal address, whose temporary terminal address, which is an address that can be used during wireless communication with the same base station, is one of its own addresses. 6. The base station data relay device according to claim 4, further comprising a base station virtual address correspondence table for storing the. 7. In the data communication, upon receipt of transmission data having a transmission source address part for storing information on the transmission source sent from the mobile terminal, and a virtual address part, the transmission source of the transmission data is received. 7. The base station data relay device according to claim 4, wherein the return destination address is stored in an address part, the virtual terminal address is stored in the virtual address part, and the virtual terminal address is sent to the server. 8. A wireless communication with a base station connects to a base station segment to which the base station belongs, performs data communication with a server via the wide area network, and wirelessly communicates with the same base station. A temporary terminal address that can be used and a virtual terminal address that does not change even if the base station segment of the connection destination is changed are used as their own addresses, and the transmission data for the data communication has the virtual terminal address. Created and transmitted, and relayed by the base station data relay device according to any one of claims 4 to 7 and the server-side data relay device according to any one of claims 1 to 3. The server sends the data to the virtual terminal based on the transmission data that reaches the server, and the server-side data relay device and the base station data relay device A mobile terminal that receives the reply data relayed by. 9. The mobile according to claim 8, further comprising a plurality of wireless interfaces for connecting to a plurality of base stations by wireless communication at the same time, each wireless interface using different temporary terminal addresses. Terminal. 10. The virtual terminal address is stored in the transmission source address portion of the transmission data, which is created for the data communication, and has a transmission source address portion for storing information of the transmission source. Or the mobile terminal according to 9. 11. In the data communication between the server and the mobile terminal according to claim 8, it does not change even if the base station segment to which the base station to which the mobile terminal is connected changes. 4. A virtual terminal address and a push destination address, which is a destination to which the server-side data relay device sends the communication data, receiving communication data addressed to the virtual terminal address from the server. And, having a center virtual address correspondence table for storing the correspondence of, when the mobile terminal newly starts wireless communication with the base station, the virtual terminal address of the mobile terminal and the return destination address Upon receipt of a notice of correspondence, based on the notice, the correspondence is recorded in the center virtual address correspondence table, and when necessary, the server side data relay device Address information center to notify the correspondence. 12. The same base station that wirelessly communicates with a base station and changes the base station of the other party to perform wireless communication based on movement, and a mobile segment that is a segment within itself and the same base station that wirelessly communicates with the base station. Belonging to a mobile network having a mobile radio interface having a self-address as a temporary relay address that can be used during radio communication with a mobile data relay device between the mobile radio interface and a mobile segment, In data communication performed via a wide area network composed of a plurality of segments between a mobile terminal that has one of its addresses as a virtual terminal address that does not change even if the mobile network to which it belongs is changed, and the server, Between the server-side segment that is the segment to which it belongs and the wide area network, A data relay device for relaying data communication, wherein the transmission data sent from the mobile terminal for the data communication and relayed by the mobile data relay device is:
Having the virtual terminal address and the temporary relay address, when the transmission data is received, the server rewrites the information of the transmission data so that the server receives it and sends reply data to the virtual terminal address. A server-side data relay device, which sends the received reply data, rewrites the information of the reply data so as to reach the mobile terminal, and sends the rewritten data to the temporary relay address. 13. A virtual address correspondence table for storing the correspondence between the virtual terminal address and the temporary relay address, the virtual terminal address included in the transmission data relayed by the mobile data relay device. 13. The server-side data relay device according to claim 12, wherein the temporary relay address and the temporary relay address are associated with each other and recorded in the server-side virtual address correspondence table. 14. A source address section which is relayed by the mobile data relay device and stores information of a source,
When receiving the transmission data in which the temporary relay address is stored in the transmission source address portion of the transmission data having a virtual address portion and the virtual terminal address is stored in the virtual address portion, The virtual address is stored in the source address part of the transmission data and sent to the server, and a destination address part for storing destination information from the server that received the transmission data and a virtual address part are provided. Upon receiving the reply data addressed to the virtual terminal address, the virtual terminal address is stored in the virtual address part of the reply data, and the temporary relay address is stored in the destination address part and transmitted. The server-side data relay device according to claim 12 or 13. 15. The same base station that wirelessly communicates with a base station and changes the base station of the other party to perform wireless communication based on movement, and a mobile segment that is a segment within itself and the same base station that wirelessly communicates with the base station. A mobile terminal having a mobile wireless interface having a temporary relay address as its own address that can be used during wireless communication with a virtual terminal address that does not change even if the mobile network to which it belongs is changed. In data communication performed between a single mobile terminal and a server via a wide area network composed of a plurality of segments,
A data relay device for relaying the data communication between the mobile segment and the mobile radio interface, the transmission data being sent by the mobile terminal for the data communication, the transmission data being the virtual terminal. The address data and the temporary relay address are rewritten so as to be sent to the server, and the transmission data is any one of claims 12 to 14.
The server-side data relay device relays the data to the server, and the server sends the virtual data to the virtual terminal address, and the server-side data relay device relays the reply data to the mobile terminal. Mobile data relay device, characterized in that it is designed to reach 16. A correspondence between the virtual terminal address and the temporary terminal address of the mobile terminal, which has one of its own addresses, which is a temporary terminal address that can be used while belonging to the same mobile network, is stored. 16. The mobile data relay device according to claim 15, further comprising a mobile virtual address correspondence table for performing. 17. Upon receipt of transmission data sent from the mobile terminal in the data communication, the transmission data having a transmission source address part for storing information on the transmission source and a virtual address part, the transmission source of the transmission data is received. The mobile data relay device according to claim 15 or 16, wherein the temporary relay address is stored in an address portion, the virtual terminal address is stored in the virtual address portion, and the virtual terminal address is transmitted to the server. 18. A part for performing wireless communication with a base station and changing the base station of the other party to perform wireless communication based on movement, and performing wireless communication with a moving segment that is a segment within itself and with the base station as a partner. A mobile radio interface having a self-address as a temporary relay address that can be used while wirelessly communicating with the same base station as the other party; When belonging to the network, the data communication is performed with the server via the wide area network, and the temporary terminal address that can be used while belonging to the same mobile network and the mobile network to which it belongs do not change The virtual terminal address is its own address, and the transmission data for the data communication is the virtual terminal address. A base station data relay device according to any one of claims 15 to 17 and a server-side data relay device according to any one of claims 12 to 14. A mobile terminal which receives the reply data transmitted by the server based on the transmission data relayed and arrived at the server and relayed by the server-side data relay device and the mobile data relay device. 19. The mobile according to claim 18, further comprising a plurality of wireless interfaces for connecting to a plurality of base stations by wireless communication at the same time, each wireless interface using different temporary terminal addresses. Terminal. 20. The virtual terminal address is stored in the transmission source address portion of the transmission data, which is created for the data communication, and has the transmission source address portion for storing information of the transmission source. Or the mobile terminal according to 19. 21. In data communication between a server and the mobile terminal according to claim 18, no change occurs even if the base station segment to which the base station to which the mobile terminal is connected changes. 15. A virtual terminal address and a push destination address, which is a destination to which the server-side data relay device sends the communication data, receiving communication data addressed to the virtual terminal address from the server. , And a center virtual address correspondence table for storing the correspondence of, the mobile terminal belongs to, wirelessly communicates with the base station, and changes the base station of the other party to wirelessly communicate based on the movement, the segment within the self And a virtual network address of the mobile terminal when a mobile network having a mobile segment newly starts wireless communication with the base station. An address information center which receives a notification of correspondence with the return destination address, records the correspondence in the center virtual address correspondence table based on the notification, and notifies the server side data relay device of this correspondence when necessary. 22. A virtual terminal address, which is connected to a base station segment to which the base station belongs by wireless communication with the base station and does not change even if the base station segment of the connection destination is changed, is set as one of its own addresses. In order to connect to a plurality of base stations, a mobile terminal having a lower radio interface and a lower radio interface whose own addresses are temporary interface addresses that can be used during wireless communication with one base station, respectively, and a server. ,
A data relay device that relays data communication between the upper and lower wireless interfaces and the wide area network in data communication performed via a wide area network composed of a plurality of segments between the mobile terminal and the server. Receiving the transmission data sent by the mobile terminal for the data communication, in which the uplink, which is the data communication path, and the downlink, which is the data communication path from the server to the mobile terminal, are different , The transmission data is rewritten so as to have the virtual terminal address and a return destination address that specifies a return destination for the transmission data, and is transmitted to the server. The transmitted transmission data belongs to the server. A server side that relays the data communication between the server side segment and the wide area network Data is relayed by the data relay device to reach the server, and the reply data addressed to the virtual address transmitted by the server based on the transmission data belongs to the same segment as the server side data relay device and the downlink wireless interface. An upper and lower base station data relay device, wherein a downlink base station data relay device, which is a station data relay device, relays and reaches the mobile terminal. 23. The upper / lower base station data relay device according to claim 22, wherein the return destination address is an address of the downlink base station data relay device. 24. A base station virtual address correspondence table for storing the correspondence between the virtual terminal address of the mobile terminal and the address of the downlink base station data relay device, 22. Or the upper and lower base station data relay device according to 23. 25. Upon receiving the transmission data sent from the mobile terminal in the data communication, the transmission data having a transmission source address section for storing transmission source information and a virtual address section, the transmission source of the transmission data 25. The upper and lower bases according to claim 22, wherein the return destination address is stored in an address part, the virtual terminal address is stored in the virtual address part, and the virtual terminal address is sent to the server. Station data relay equipment. 26. Moving by connecting to a base station segment to which the base station belongs by wirelessly communicating with the base station and using as one of its own addresses a virtual terminal address that does not change even if the connected base station segment is changed In data communication performed between a terminal and a server via a wide area network composed of a plurality of segments, data for relaying the data communication between a server side segment which is a segment to which the server belongs and the wide area network A relay device, wherein the uplink that is a data communication path from the mobile terminal to the server and the downlink that is a data communication path from the server to the mobile terminal are different 23. Sent from the mobile terminal for
25. When receiving the transmission data relayed by the upper and lower base station data relay device according to any one of 25 to 25, the transmission data so that the server receives the transmission data and sends reply data to the virtual terminal address. Information is rewritten and sent, and when the reply data is received, the reply data information is rewritten and sent so that the reply data is relayed by the downlink base station data relay device and reaches the mobile terminal. Server side data relay device. 27. A virtual address, which is connected to the base station by the wireless communication, performs the data communication with the server via the wide area network, and which does not change even if the connected base station changes, is used as its own address. , A lower radio interface and a lower radio interface for connecting to a plurality of base stations, and the lower radio interface and the lower radio interface each have a temporary interface address that can be used during wireless communication with one base station. For the data communication, which is its own address, and the uplink which is a data communication path from the mobile terminal to the server and the downlink which is a data communication path from the server to the mobile terminal are different Created so that the transmission data of has the virtual terminal address, Serial sending from the vertical interface, the transmission data sent from the upper and lower base station data relay apparatus according to any one of claims 22 to 25 claim 2
6. The reply which is relayed by the server side data relay device according to 6, reaches the server, is sent out by the server based on the transmission data, and is relayed by the server side data relay device and the base station data relay device. A mobile terminal that receives data from the downlink wireless interface. 28. The virtual terminal address is stored in the transmission source address portion of the transmission data having a transmission source address portion having transmission source information created and transmitted for the data communication, and then transmitted. 27. The mobile terminal according to 27.