Mobile proxy apparatus and mobile communication method

• US 20030225900A1
• Filed: 01/06/2003
• Published: 12/04/2003
• Est. Priority Date: 05/30/2002
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Morishige, Takehiro, Takeda, Yukiko, Tanaka, Koji, Inouchi, Hidenori
• Granted Patent: US 7,162,529 B2
• Time in Patent Office: Days
• US Class Current: 709/230
• CPC Class Codes: H04L 61/251 between different IP versions
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2585 through application level gateway [ALG]
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/045 involving different protocol versions, e.g. MIPv4 and MIPv6
• CPC Class Codes: H04W 88/182 Network node acting on behalf of an other network entity, e.g. proxy

Abstract

Since the Mobile IP is defined under the assumption that a mobile node roams between networks conforming to the same communications protocols, mobile communications between IPv4 and IPv6 are not possible. Further, a translation of the location registration messages also requires translating the format between different protocol layers. To solve this problem, a mobile proxy apparatus 2 is provided between a home network 1a and a foreign network 1b governed by different communications protocols. The mobile proxy apparatus 2 has a DNS-ALG function, a translator function and a Mobile IP function, and, by combining these functions, performs address translation and format translation on Mobile IP messages and user packets. The MN4 has Mobile IPv4 and Mobile IPv6 functions and executes communication suitable for the communications protocol governing the network to which it moves.

Claims

1. A mobile proxy apparatus including a protocol translator interconnecting a network A conforming to a protocol P and a network B conforming to a protocol Q, the protocol translator comprising:

an address translation function to perform a conversion between an address conforming to the communications protocol P and an address conforming to the communications protocol Q;

a detection function to detect a communication conforming to a particular protocol;

a format translation function to convert a particular protocol between a format identifiable in the network A and a format identifiable in the network B; and

a function to process a communication conforming to a mobile communications protocol;

wherein, when a terminal M belonging to the network A moves to the network B, a protocol exchanged between a server H, managing location information of the terminal M in the network A, and the terminal M is converted between a format valid in one of the networks and a format valid in the other network and relayed between the networks by using the address translation function and the format translation function.

2. A mobile proxy apparatus according to claim 1, further including:

a function to extract address information contained in the protocol exchanged between the network A and the network B by using the detection function of detecting a communication conforming to a particular protocol; and

a function to dynamically create an address V valid in the network A and an address W valid in the network B, the addresses being used by a sending terminal H and a receiving terminal M;

wherein an association between the extracted address information and the dynamically created addresses has address translation information containing lifetime information and, in subsequent communications, the address conversion is executed according to the address translation information and the converted addresses are relayed.

3. A mobile proxy apparatus according to claim 1, wherein after the terminal M has moved to the network B from the network A conforming to the protocol P, when an address acquisition protocol for the terminal M is dispatched from a terminal C present in the network B conforming to the protocol Q, an address conforming to the protocol Q which corresponds to an address of the terminal M valid in the network A conforming to the protocol P is informed to the terminal C so that a communication from the terminal C can directly be routed to the terminal M in the network B conforming to the protocol Q.

4. A mobile proxy apparatus according to claim 1, further including:

a function to encapsulate communication data; and

a function to decapsulate the encapsulated data;

wherein the mobile proxy apparatus decapsulates encapsulated communication data sent from the network A and conforming to the protocol P, converts both inner and outer communication data into addresses valid in the network B conforming to the protocol Q, and encapsulates again the converted communication data for relaying.

5. A mobile proxy apparatus according to claim 1, wherein the terminal M belonging to the network A, when moving to the network B, creates address information valid in the network B and containing an address of the terminal M valid in the network A, extracts the address of the terminal M valid in the network A from the address information and relays it to the server H managing the location information in the network.

6. A mobile proxy apparatus according to claim 1, further including:

a particular protocol information creation function to create format information on a particular protocol provided by an external device; and

an external device setting function to inform a connected external device of the created information;

wherein, upon receiving a mobile communications protocol communicated between the terminal M that has moved from the network A to the network B and the server H present in the network A and managing the location information, the mobile proxy apparatus creates, from information included in the mobile communications protocol, format information on a particular protocol provided by an external device and informs it to the external device.

7. A mobile proxy apparatus according to claim 1, wherein the mobile communications protocol is a Mobile IP.

8. A mobile proxy apparatus according to claim 1, wherein the network A to which the terminal M belongs is a network conforming to an IPv4 protocol and the network B to which the terminal M moves is a network conforming to an IPv6 protocol.

9. A mobile proxy apparatus according to claim 1, wherein the network A to which the terminal M belongs is a network conforming to an IPv6 protocol and the network B to which the terminal M moves is a network conforming to an IPv4 protocol.

10. A mobile proxy apparatus according to claim 1, wherein the terminal M includes

a function to perform processing according to a Mobile IPv4 and a Mobile IPv6 and

a function to identify a protocol governing the network to which a mobile terminal has moved, and

wherein the terminal M identifies a protocol of the network to which it has moved from a protocol of a router advertisement which it receives in the visited local network, and sends a location registration conforming to the visited local network.

11. A mobile proxy apparatus according to claim 2, wherein the address information includes a real home address of the terminal M used in the network A, a virtual home address of the terminal M valid in the network B and a care of address of the terminal M valid in the network B.

12. A mobile communication method for interconnecting a network A conforming to a protocol P and a network B conforming to a protocol Q, comprising the steps of:

performing a conversion between an address conforming to the communications protocol P and an address conforming to the communications protocol Q;

detecting a communication conforming to a particular protocol;

converting a particular protocol between a format identifiable in the network A and a format identifiable in the network B; and

processing a communication conforming to a mobile communications protocol;

wherein, when a terminal M belonging to the network A moves to the network B, a protocol exchanged between a server H managing location information of the terminal M in the network A and the terminal M is converted between a format valid in one of the networks and a format valid in the other network and relayed between the networks by using the address translation function and the format translation function.