Method of arranging data transfer in a wireless telecommunication system

• US 20030185202A1
• Filed: 02/25/2003
• Published: 10/02/2003
• Est. Priority Date: 08/25/2000
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Maenpaa, Henri
• Granted Patent: US 7,539,138 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 61/5084 Providing for device mobility network addressing or numbering for mobility support in wireless networks H04W8/26; mobile IP H04W80/04
• CPC Class Codes: H04W 36/0005 Control or signalling for completing the hand-off
• CPC Class Codes: H04W 36/026 Multicasting of data during hand-off
• CPC Class Codes: H04W 36/10 Reselecting an access point controller
• 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 92/02 Inter-networking arrangements

Abstract

A method of arranging data transfer in a wireless telecommunication system comprising at least one wireless terminal, a first radio access gateway and a first base station connected thereto, a second radio access gateway and a second base station connected thereto. The first base station and the first radio access gateway are arranged to transmit data between the terminal and an end point in an IP-based network. Address information on the second radio access gateway is specified to the first radio access gateway when it is detected that handover from the first base station to the second base station is needed for the terminal. Data directed to the terminal is transmitted through the first radio access gateway and the second radio access gateway to a wireless network after the terminal has been handed over to the second base station. The address information on the second radio access gateway is transmitted to the end point in the IP network and the data directed to the terminal is transmitted from the end point to the second radio access gateway.

Claims

1. A method of arranging data transfer in a wireless telecommunication system comprising at least one wireless terminal, a first radio access gateway and a first base station connected thereto, a second radio access gateway and a second base station connected thereto, in which system said first radio access gateway is arranged to perform a protocol conversion on the data between the terminal and an end point in an IP-based network, the method comprising:

specifying to said first radio access gateway address information on said second radio access gateway in response to the fact that it is detected that handover from the first base station to the second base station is needed for the terminal,

transmitting the data directed to the terminal through said first radio access gateway and said second radio access gateway to the terminal in response to the fact that the terminal has been handed over to the second base station,

transmitting the address information on said second radio access gateway to the end point in the IP network, and

transmitting the data directed to the terminal from the end point to said second radio access gateway on the basis of the address information.

2. A method as claimed in claim 1, further comprising:

transmitting address information on the end point to said second radio access gateway, and

transmitting the data received from the terminal on said second radio access gateway to the end point on the basis of the address information on the end point.

3. A method as claimed in claim 1, wherein said first radio access gateway, said second radio access gateway and the end point are controlled by one or more call control entities.

4. A method as claimed in claim 3, wherein said first radio access gateway is controlled by a first call control entity, said second radio access gateway is controlled by a second call control entity and the end point is controlled by a third call control entity,

the first and the second call control entities comprise configuration information on the radio access gateways, the base stations connected to the radio access gateways and the call control entities controlling the radio access gateways,

information about a need to change the radio access gateway is transmitted from the first call control entity to the second call control entity in response to the fact that on the basis of the information received from the first radio access gateway, it has been detected that handover to the second base station is necessary,

the address information on the second radio access gateway is transmitted to said first radio access gateway from the first call control entity,

a handover command to establish a connection to the second base station is transmitted from said first radio access gateway to the terminal,

a connection between the terminal and said second radio access gateway is established,

the settings of said first radio access gateway are changed on the basis of the address information on the second radio access gateway,

the data directed to the terminal is transmitted from said first radio access gateway to said second radio access gateway,

a data redirection request comprising the address information on the second radio access gateway is transmitted from the first call control entity to the third call control entity, and

a command to transmit the data to said second radio access gateway instead of the first radio access gateway is transmitted from the third call control entity to the end point.

5. A method as claimed in claim 1, wherein

the data transmitted between the terminal and the IP-based network comprises voice information.

6. A method as claimed in claim 1, wherein

the address information on said second radio access gateway is transmitted to the end point in response to the fact that a predetermined period of time has elapsed since the handover.

7. A method as claimed in claim 1, wherein

the data transfer has been arranged in the IP-based network by one of the following protocols:

H.323, SIP (Session Initiation Protocol) or H.248.

8. A method as claimed in claim 1, wherein said terminal, said first and said second base stations support the GSM standard, and

said radio access gateways comprise means for carrying out the protocol conversion between the wireless network according to the GSM system and the IP-based network.

9. A wireless telecommunication system comprising at least one wireless terminal, a first radio access gateway and a first base station connected thereto, a second radio access gateway and a second base station connected thereto, in which system said first radio access gateway is arranged to perform a protocol conversion on the data between the terminal and an end point in an IP-based network, specification of address information on said second radio access gateway to said first radio access gateway is arranged in response to the fact that it is detected that handover from the first base station to the second base station is needed for the terminal,

said first radio access gateway is arranged to transmit the data directed to the terminal to said second radio access gateway on the basis of the address information in response to the fact that the terminal has been handed over to the second base station,

transmission of the address information on the second radio access gateway to the end point in the IP network is arranged, and

said end point is arranged to transmit the data directed to the terminal to said second radio access gateway on the basis of the address information.

10. A telecommunication system as claimed in claim 9, wherein said first radio access gateway and said second radio access gateway are controlled by at least one call control entity arranged to detect a need for handover on the basis of the information received from said first radio access gateway and transmit the address information on said second radio access gateway to said first radio access gateway and the end point.

11. A telecommunication system as claimed in claim 10, wherein the call control entity controlling said first radio access gateway is arranged to transmit address information on the end point to said second radio access gateway or the call control entity controlling the same, and

said second radio access gateway is arranged to transmit the data received from the terminal to the end point on the basis of the address information on the end point.

12. A network part of a wireless telecommunication system, the network part being connected to a first base station, wherein said network part is arranged to perform a protocol conversion on the data between at least one wireless terminal served by the first base station and an end point in an IP-based network, said network part is arranged to specify address information on a radio access gateway of a second network part in response to the fact that it has been detected that handover is needed from the first base station to a base station connected to said second network part,

said network part is arranged to transmit the data directed to the terminal to said second network part on the basis of the address information, and

said network part is arranged to transmit the address information on said second network part to the end point.

13. A network part as claimed in claim 12, wherein said network part comprises programmable means for

specifying the address information on the radio access gateway of said second network part,

routing the data directed to the terminal on the basis of the specified address information, and

transmitting the address information on said second network part to the end point.

14. A network part as claimed in claim 12 or 13, wherein said network part comprises a gateway functionality described in the H.323 standard and an H.323 gatekeeper controlling the same.