Radio communication control station, radio communication terminal, home agent, and radio communication method

• US 20020064141A1
• Filed: 10/09/2001
• Published: 05/30/2002
• Est. Priority Date: 11/24/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Sakakura, Takashi
• Granted Patent: US 7,103,023 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation

Abstract

A radio communication control station including a packet receiver, a paging controller, a location information receiver, and a retriever. The packet receiver receives an IP packet destined for a radio communication terminal subscribing to one of sub-networks constituting a composite radio communication network. The paging controller causes one of the sub-networks to page the radio communication terminal. The location information receiver receives location information on a current location of the radio communication terminal from the radio communication terminal. The retriever retrieves candidates of sub-networks that can be employed by the radio communication terminal on the basis of the location information on the radio communication terminal. The radio communication terminal selects a sub-network for its use among from the candidates and establishes an environment for communication with the sub-network.

Claims

1. A radio communication control station comprising:

a packet receiver for receiving an IP packet destined for a radio communication terminal subscribing to one of sub-networks constituting a composite radio communication network;

a paging controller for causing one of the sub-networks to page the radio communication terminal;

a location information receiver for receiving location information on a current location of the radio communication terminal from the radio communication terminal; and

a retriever for retrieving candidates of sub-networks that can be employed by the radio communication terminal on the basis of the location information on the radio communication terminal.

2. A radio communication control station according to claim 1, wherein the paging controller causes a sub-network having a maximum service area among the sub-networks to page the radio communication terminal.

3. A radio communication control station according to claim 1, wherein the paging controller transmits information on the candidates of sub-networks, which can be employed by the radio communication terminal, to the radio communication terminal.

4. A radio communication control station according to claim 3, further comprising a packet transmitter for modifying the IP packet, which has been already received by the packet receiver, to be matched with the selected sub-network when an connection environment is established between the sub-network selected by the radio communication terminal for its use and the radio communication terminal, the packet transmitter transmitting the modified IP packet to the radio communication terminal.

5. A radio communication control station according to claim 1, further comprising an authenticator for verifying authentication information of the radio communication terminal received from the radio communication terminal.

6. A radio communication control station according to claim 5, further comprising a transmitter for transmitting information to a home network to which the radio communication terminal originally subscribes, the authenticator executing an authentication for the radio communication when the radio communication control station detects that communication between the sub-network and the radio communication terminal has ceased after an connection environment has been established between the sub-network selected by the radio communication terminal for its use and the radio communication terminal, the transmitter informing the home network of a transfer-destination address of the radio communication terminal assigned before the communication has ceased when the radio communication control station detects that the communication has ceased.

7. A radio communication control station according to claim 1, further comprising a location information database storing location information on all base stations belonging to the composite radio communication network, the retriever retrieving from the location information database the candidates of sub-networks that can be employed by the radio communication terminal on the basis of the location information on the radio communication terminal.

8. A radio communication control station according to claim 1, further comprising a storage at which the location information received from the radio communication terminal is registered as a latest location information of the radio communication terminal, the paging controller selecting at least one base station, which is suitable for the latest location information of the radio communication terminal registered at the storage, from among the sub-network used for paging and causing the selected base station to page the radio communication terminal.

9. A radio communication control station according to claim 3, wherein the paging controller transmits a message designating attributes of quality of service to the radio communication terminal when the attributes of quality of service are designated in the IP packet received by the packet receiver.

10. A radio communication control station according to claim 3, wherein the paging controller transmits information on a sub-network that should be employed to the radio communication terminal when the IP packet received by the packet receiver is effectual only in the specific sub-network.

11. A radio communication control station according to claim 1, further comprising an IP management module for allocating a temporary IP address to the radio communication terminal when the radio communication terminal selects a sub-network that does not comprises an IP address allocating mechanism for allocating IP addresses to terminals.

13. A radio communication terminal according to claim 12, wherein the location information transmitter acquires the location information of the radio communication terminal and transmits the location information to the radio communication control station when change of sub-network used by the radio communication terminal becomes necessary, the selector obtaining information on candidates of sub-networks available for the radio communication terminal and selecting a sub-network, which the radio communication terminal utilizes, from the candidates of sub-networks, the setter resetting up the communication mechanism to be matched with the selected sub-network.

14. A radio communication terminal according to claim 13, wherein the location information transmitter acquires the location information of the radio communication terminal and transmits the location information to the radio communication control station when the radio communication terminal receives an IP packet requiring attributes of quality of service that are different from the attributes of quality of service currently used, the selector obtaining information on candidates of sub-networks available for the radio communication terminal and selecting a sub-network, which the radio communication terminal utilizes, from the candidates of sub-networks, the setter resetting up the communication mechanism to be matched with the selected sub-network.

15. A radio communication terminal according to claim 12, wherein the selector separately selects a sub-network for transmission by the terminal and a sub-network for reception by the terminal, the negotiator negotiates with both of the selected sub-networks for establishing environments for communication between respective sub-networks and the terminal.

17. A home agent according to claim 16, wherein when communication between the visited sub-network and the radio communication terminal has ceased after the destination terminal obtains the temporary IP address effective in the visited sub-network, the home agent is notified of a temporary IP address of the radio communication terminal that was effective before the communication has ceased and registers the temporary IP address of the radio communication terminal at the home agent.

19. A radio communication method according to claim 18, further comprising transmitting information on the candidates of sub-networks, which can be employed by the radio communication terminal, to the radio communication terminal.

20. A radio communication method according to claim 19, further comprising sending the radio communication terminal the IP packet, which has been received by the packet receiver, to be matched with the selected sub-network after an connection environment has been established between the sub-network selected by the radio communication terminal for its use and the radio communication terminal.

12. A radio communication terminal comprising:

a location information transmitter for acquiring location information on a current location of the radio communication terminal and transmitting the location information to a radio communication control station when the radio communication terminal has been paged by the radio communication control station in one of sub-networks constituting a composite radio communication network;

a selector for selecting a sub-network, which the radio communication terminal utilizes, from candidates of sub-networks available for the radio communication terminal once receiving information on the candidates of sub-networks;

a setter for setting up a communication mechanism to be matched with the selected sub-network; and

a negotiator for negotiating with the selected sub-network for establishing an environment of communication between the selected sub-network and the radio communication terminal.

16. A home agent provided in a sub-network of a composite radio communication network, and supervising, receiving, and transferring IP packets destined for radio communication terminals subscribing to the sub-network, the home agent comprising a transferrer that transfers an IP packet to a destination terminal using an IP address inherent in the destination terminal without transferring the IP packet to another sub-network when the destination terminal exists effectively in the sub-network where the home agent is provided and the inherent IP address can be used in the sub-network, the transferrer transferring an IP packet to a radio communication control station provided in the composite radio communication network when the destination terminal does not effectively exist in any sub-networks constituting the composite radio communication network, the transferrer using a temporary IP address to transfer IP packets received after the destination terminal obtains the temporary IP address that is effective in a visited sub-network different from the network at which the home agent is provided.

18. A radio communication method comprising:

receiving an IP packet destined for a radio communication terminal subscribing to one of sub-networks constituting a composite radio communication network;

causing one of the sub-networks to page the radio communication terminal;

receiving location information on a current location of the radio communication terminal from the radio communication terminal; and

retrieving candidates of sub-networks that can be employed by the radio communication terminal on the basis of the location information on the radio communication terminal.