Handoff system and method for dual mode terminal

Abstract

In a handoff system and method for a dual mode terminal, the handoff system includes: a dual mode terminal which receives a message containing location information of a router of a second network while performing handoff from a first network to the second network, and which transmits a registration request message containing the location information of the router; and a home agent which transcodes data transmitted from a content providing server to be adapted for a bandwidth of the second network on the basis of information contained in the registration request message received from the dual mode terminal, and which transmits the transcoded data to the dual mode terminal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which like reference symbols indicate the same or similar components, wherein:

FIG. 1 is a diagram illustrating a handoff process of a dual mode terminal between heterogeneous networks;

FIG. 2 is a diagram illustrating a registration request message format of the dual mode terminal;

FIG. 3 is a diagram of a handoff system of a dual mode terminal according to an exemplary embodiment of the present invention;

FIG. 4 is a flowchart of a transmission process of a registration request message of the dual mode terminal according to an exemplary embodiment of the present invention; and

FIG. 5 is a diagram illustrating a handoff process of a dual mode terminal according to an exemplary embodiment of the present invention.

Claims

1. A handoff system of a dual mode terminal, comprising: a dual mode terminal which receives, from a router of a second network, a message containing location information of the router of the second network while performing handoff from a first network to the second network, and which transmits a registration request message containing the location information of the router of the second network; anda home agent which transcodes data transmitted from a content providing server to be adapted for a bandwidth of the second network on the basis of information contained in the registration request message transmitted from the dual mode terminal, and transmits the transcoded data to the dual mode terminal.

2. The handoff system according to claim 1, wherein the location information of the router of the second network comprises a care-of address of the router of the second network.

3. The handoff system according to claim 1, wherein the registration request message comprises at least one of information about each network, information about a transcoding flag which indicates whether transcoding is needed, and information about a media format decodable by the dual mode terminal.

4. The handoff system according to claim 3, wherein the dual mode terminal sets the transcoding flag to “1” when the data needs transcoding on the basis of information about a service bandwidth of the second network.

5. The handoff system according to claim 3, wherein the dual mode terminal sets the transcoding flag to “0” when the data does not need transcoding on the basis of information about a service bandwidth of the second network.

6. The handoff system according to claim 3, wherein the home agent comprises: a registration information database for storing information contained in the registration request message received from the dual mode terminal; anda transcoding module for transcoding data transmitted from the content providing server to be adapted for the bandwidth of the second network on the basis of the information about the transcoding flag contained in the registration request message.

7. The handoff system according to claim 6, wherein the registration information database comprises at least one of information about the dual mode terminal, information about an old/new network, and information about the transcoding flag which indicates whether the transcoding is needed.

8. A dual mode terminal comprising a controller which receives, from a router of a second network, a message containing location information of the router of the second network while performing handoff from a first network to the second network, and which transmits to a home agent a registration request message containing the location information of the router of the second network.

9. The dual mode terminal according to claim 8, wherein the location information of the router of the second network comprises a care-of address of the router of the second network.

10. The dual mode terminal according to claim 8, wherein the registration request message comprises at least one of information about each network, information about a transcoding flag which indicates whether transcoding is needed, and information about a media format decodable by the terminal.

11. The dual mode terminal according to claim 10, wherein the controller sets the transcoding flag to “1” when the data needs transcoding on the basis of information about a service bandwidth of the second network.

12. The dual mode terminal according to claim 10, wherein the controller sets the transcoding flag to “0” when the data does not need transcoding on the basis of information about a service bandwidth of the second network.

13. A home agent comprising a controller which transcodes data transmitted from a content providing server to be adapted for a bandwidth of a second network on the basis of information contained in a registration request message received from a dual mode terminal performing handoff from a first network to the second network, and which transmits the transcoded data to the dual mode terminal.

14. The home agent according to claim 13, wherein the registration request message comprises at least one of location information about a router of the second network, information about each of the first network and the second network, information about a transcoding flag which indicates whether transcoding is needed, and information about a media format decodable by the terminal.

15. The home agent according to claim 14, wherein the location information of the router of the second network comprises a care-of address of the router of the second network.

16. The home agent according to claim 14, further comprising: a registration information database for storing information contained in the registration request message received from the dual mode terminal; anda transcoding module for transcoding data transmitted from the content providing server to be adapted for the bandwidth of the second network on the basis of the information about the transcoding flag contained in the registration request message.

17. The home agent according to claim 16, wherein the registration information database comprises at least one of information about the dual mode terminal, information about one of an old network and a new network, and information about the transcoding flag which indicates whether the transcoding is needed.

18. A handoff method of a dual mode terminal, comprising the steps of: receiving, from a router of a second network, a message containing location information of the router of the second network while performing handoff from a first network to the second network;transmitting a registration request message containing the location information of the router of the second network; andtranscoding data transmitted from a content providing server to be adapted for a bandwidth of the second network on the basis of information contained in the registration request message, and transmitting the transcoded data to a relevant terminal.

19. The method according to claim 18, wherein the location information of the router of the second network comprises a care-of address of the router of the second network.

20. The method according to claim 18, wherein the registration request message comprises at least one of information about each network, information about a transcoding flag which indicates whether transcoding is needed, and information about a media format decodable by the terminal.

21. The method according to claim 20, wherein the registration request message containing the location information of the router of the second network is transmitted after setting the transcoding flag to “1” when the data needs transcoding on the basis of information about a service bandwidth of the second network.

22. The method according to claim 20, wherein the registration request message containing the location information of the router of the second network is transmitted after setting the transcoding flag to “0” when the data does not need transcoding on the basis of information about a service bandwidth of the second network.