Communication system and communication method

• US 20060117111A1
• Filed: 11/24/2004
• Published: 06/01/2006
• Est. Priority Date: 11/28/2003
• Status: Active Grant

• Current Assignee: Godo Kaisha IP Bridge 1 (IP Bridge, Inc.)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Sudo, Hiroaki
• Granted Patent: US 8,051,198 B2
• Time in Patent Office: Days
• US Class Current: 709/238
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• CPC Class Codes: H04W 8/085 involving hierarchical organized mobility servers, e.g. hierarchical mobile IP [HMIP]
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/005 Data network PoA devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A communication system enabling significant reduction in delay in handover between MAPs without increasing the number of MAPs to install. In the communication system, MAP(101) issues a Router Advertisement to AR(111) to AR(118). Particularly, MAP(101) assigns a plurality of Router Advertisements of a source of care-of address (RCOA) to register with HA to AR(118) of a cell on either side of a boundary of areas for each MAP. MN(107) receives a Router Advertisement transmitted from AR that is a communicating party among AR(119) to AR(126), and using the Router Advertisement, generates care-of addresses, RCOA and LCOA. AR(111) to AR(118) transmit the Router Advertisement RA generated by MAP(101) to MN in communication. Further, AR(111) to AR(118) transmit the care-or-addresses, RCOA and LCOA, issued from MN(107) to MAP(101).

Claims

1. A communication system comprising:

a mobility anchor point which is connected to a plurality of access routers and which issues a care-of address to a communication terminal apparatus communicating with said access routers;

the access routers which communicate with the communication terminal apparatus and transmit the care-of address to the communication terminal apparatus;

a network which connects the mobility anchor point and the access routers, and transmits the care-of address to a home agent to which the communication terminal apparatus belongs; and

the home agent which stores the care-of address and a home address in association with each other for each communication terminal apparatus, and transmits data that is transmitted to the home address of the communication terminal apparatus to a destination indicated by the care-of address,

wherein the mobility anchor point issues to a communication terminal apparatus communicating with an access router of an adjacent cell to a cell of a mobility anchor point to which said communication terminal apparatus does not belong, another care-of address that is effective in the cell of said access router and said adjacent cell.

2. The communication system according to claim 1, wherein the mobility anchor point issues a care-of address which is variable in a plurality of cells and effective in the cell of the access router and the another cell adjacent to the cell.

3. The communication system according to claim 1, wherein the mobility anchor point makes the number of cells variable, the cells effective in another care-of address to assign to the cells on a boundary of the mobility anchor point.

4. The communication system according to claim 3, wherein the mobility anchor point detects moving speed of a communication terminal apparatus, and when communicating with a communication terminal apparatus moving at high speed, issues the another care-of address to a larger number of cells than in a case of communicating with a communication terminal apparatus moving at low speed.

5. A communication method, in a communication system comprising:

a mobility anchor point which is connected to a plurality of access routers and which issues a care-of address to a communication terminal apparatus communicating with said access routers;

the access routers which communicate with the communication terminal apparatus, and transmit the care-of address to the communication terminal apparatus;

a network which connects the mobility anchor point and the access routers, and transmits the care-of address to a home agent to which the communication terminal apparatus belongs; and

the home agent which stores the care-of address and a home address in association with each other for each communication terminal apparatus, and transmits data that is transmitted to the home address of the communication terminal apparatus to a destination indicated by the care-of address,

wherein another care-of address is issued, to a communication terminal apparatus communicating with an access router of an adjacent cell to a cell of a mobility anchor point to which said communication terminal apparatus does not belong, that is effective in the cell of said access router and said adjacent cell.

6. The communication method according to claim 5, wherein issued is a care-of address which is variable in a plurality of cells and effective in the cell of the access router and the another cell adjacent to the cell.

7. The communication method according to claim 5, wherein the number of cells is made variable, the cells effective in another care-of address to assign to the cells on a boundary of the mobility anchor point.

8. The communication method according to claim 7, wherein moving speed of a communication terminal apparatus is detected, and when communicating with a communication terminal apparatus moving at high speed, the another care-of address is issued to a larger number of cells than in a case of communicating with a communication terminal apparatus moving at low speed.