Intersystem handover with modified parameters

• US 20030157935A1
• Filed: 03/11/2003
• Published: 08/21/2003
• Est. Priority Date: 02/28/2000
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Kauhanen, Timo
• Granted Patent: US 7,254,392 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 36/0083 Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems

Abstract

A method for a communication system that includes a first node, a second node and a third node. In the method a connection is established between the first node and the second node based on predefined parameters. Handover of the connection is initiated so that the connection may continue between the first node and the third node. A default value is used for at least one connection parameter required for said connection between the first node and the third node. If it is determined as necessary, the value of said at least one parameter is then modified after the connection has been established.

Claims

1. A method in a cellular communication system wherein a mobile station is arranged to be served by a second node and a third node, said first and second nodes belonging to a first and second communication system that are based on different rules of communication, comprising the steps of:

establishing a connection between the mobile station and the second node based on predefined parameters;

initiating handover procedure of the connection from the first communication system to the second communication system so that the connection may continue between the mobile station and the third node;

using a default value for at least one connection parameter required to establish the connection between the mobile station and the third node during the handover procedures, the default value being based on a quality of service parameter of the connection between the mobile station and the second node; and

modifying, if determined necessary, the value of said at least one parameter.

2. A method as claimed in claim 1, wherein the connection to be handed over is a data connection.

3. A method as claimed in claim 2, wherein the data connection is a high speed data connection.

4. A method as claimed in any preceding claim, wherein the second node is a controller of a packet switched communication network.

5. A method as claimed in claim 4, wherein the controller is a radio access network controller.

6. A method as claimed in any preceding claim, wherein the third node is a controller of a circuit switched communication network.

7. A method as claimed in claim 8, wherein the controller of the circuit switched communication network is a mobile switching centre.

8. A method as claimed in any preceding claim, wherein said default value of the parameter comprises a parameter indicating the number of traffic channels for a circuit switched connection.

9. A method as claimed in claim 8, wherein said default value for the parameter indicating the number of traffic channels is determined based on the bitrate of a packet switched connection between the mobile station and the second node.

10. A method as claimed in any preceding claim, wherein the default value of the parameter is determined by mapping at least one of the bearer characteristics of the connection between the mobile station and the second node in characteristic of the connection between the mobile station and the third node.

11. A method as claimed in any of the preceding claims, wherein the step of modifying comprises:

transmitting modify request from the third node to the mobile station, the request containing bearer capability information and said at least one default parameter;

determining whether the proposed default parameters are acceptable by the mobile station; and

transmitting a response from the mobile station to the third node indicating the result of the determination.

12. A method as claimed in claim 11, wherein the response comprises one of the following information:

modification completed acknowledgement together with said at least one default parameter;

modification completed acknowledgement together with at least one parameter that is modified from the default parameter;

or

modification rejected announcement.

13. A cellular communication system comprising:

a mobile station, a second node and a third node, the second and third nodes being arranged to operate based on different rules of communication, wherein the mobile station may communicate with the second node and the third node and a connection between the mobile station and the second node can be handed over to a connection between the mobile station and the third node, the set-up of a connection between the mobile station and the third node being based on at least one parameter that is different from the parameters required for the set-up of the connection between the mobile station and the second node;

a controller for determining a default value for said at least one different parameter based on a quality of service parameter of the connection between the mobile station and the second node to be used for setting up the connection between the mobile station and the third node during the handover procedures; and

means for modifying the value of said at least one parameter.

14. A communication system as claimed in claim 13, wherein the connection to be handed over is a data connection.

15. A communication system as claimed in claim 14, wherein the data connection is a high speed data connection.

16. A communication system as claimed in any of claims 13 to 15, wherein the second node is a controller of a packet switched communication network.

17. A communication system as claimed in claim 16, wherein the controller is a radio access network controller.

18. A communication system as claimed in any of claims 13 to 17, wherein the third node is a controller of a circuit switched communication network.

19. A communication system as claimed in claim 18, wherein the controller of the circuit switched communication network is a mobile switching centre.

20. A communication system as claimed in any of claims 13 to 19, wherein said parameter comprises a parameter indicating the number of traffic channels for a circuit switched connection.

21. A communication system as claimed in claim 20, wherein the controller is adapted to determine said parameter indicating the number of traffic channels based on the bitrate of a packet switched connection between the mobile station and the second node.

22. A communication system as claimed in any of claims 13 to 21, wherein the default parameter is determined by mapping at least one of bearer characteristics of the connection between the mobile station and the second node in characteristic of the connection between the mobile station and the third node.

23. A communication system as claimed in any of claims 13 to 22, wherein the third node is adapted to generate and transmit a modify request to the mobile station, the request containing bearer capability information and said at least one default parameter, and the mobile station is adapted to determine whether the proposed default parameters are acceptable and to generate and transmit a response to the third node indicating the result of the determination.

24. A communication system as claimed in claim 23, wherein the response comprises one of the following information:

modification completed acknowledgement together with said at least one default parameter;

modification completed acknowledgement together with at least one parameter that is modified from the default parameter;

or

modification rejected announcement.