Maintaining an IP connection in a mobile network

• US 20070019610A1
• Filed: 06/21/2006
• Published: 01/25/2007
• Est. Priority Date: 06/21/2005
• Status: Active Grant

• Current Assignee: Seven Networks LLC (SoftBank Group Corp.)
• Original Assignee: Seven Networks International Oy (SoftBank Group Corp.)
• Inventors: Daavittila, Mikko, Everitt, Andrew, Ahonen, Jukka, Salorinne, Seppo, Vuornos, Lauri, Backholm, Ari
• Granted Patent: US 7,774,007 B2
• Time in Patent Office: Days
• US Class Current: 370/349
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04W 76/25 Maintenance of established connections
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A method for IP [=Internet Protocol] communication between a mobile terminal and its correspondent node in a mobile radio network. The method comprises establishing (2-2) an IP connection between the mobile terminal and its correspondent node. After detecting a period of inactivity in the IP connection, (2-4) keep-alive messages are sent via the IP connection at predetermined intervals, which are varied. The method comprises monitoring (2-6) the lengths of several periods of inactivity at which the mobile radio network disconnects the IP connection. Based on the monitored lengths of periods of inactivity, a maximum interval (T_INT) between keep-alive messages is determined (2-8) such that the maximum interval meets a predetermined criterion of statistical confidence, and the interval between keep-alive messages is set (2-10) to the maximum interval (T_INT).

Claims

1. A method for IP [=Internet Protocol] communication between a mobile terminal and its correspondent node in a mobile radio network, the method comprising:

establishing an IP connection between the mobile terminal and its correspondent node;

in response to detecting a period of inactivity in the IP connection, sending keep-alive messages via the IP connection at predetermined intervals;

varying the predetermined intervals and monitoring the lengths of several periods of inactivity at which the mobile radio network disconnects the IP connection;

based on the several monitored lengths of periods of inactivity, determining a maximum interval between keep-alive messages such that the maximum interval meets a predetermined criterion of statistical confidence; and

setting the interval between keep-alive messages to the maximum interval.

2. A method according to claim 1, further comprising sending the keep-alive messages from the mobile terminal.

3. A method according to claim 1, further comprising sending the keep-alive messages from the correspondent node.

4. A method according to claim 1, further comprising determining the maximum interval in the mobile terminal.

5. A method according to claim 1, further comprising determining the maximum interval in the correspondent node.

6. A method according to claim 1, further comprising storing the maximum interval in the mobile terminal, in association with an identifier of the mobile radio network.

7. A method according to claim 1, further comprising sending the maximum interval in association with the identifier of the mobile radio network to the mobile terminal'"'"'s home network for storage and future inquiry.

9. A computer program product for a mobile terminal, the computer program product comprising program code instructions for causing the mobile terminal to carry out the steps of claim 1 when the computer program product is executed in the mobile terminal.

8. A mobile terminal for a mobile network, the mobile terminal comprising:

means for establishing an IP connection between the mobile terminal and its correspondent node;

means, responsive to detecting a period of inactivity in the IP connection, for sending keep-alive messages via the IP connection at predetermined intervals;

means for varying the predetermined intervals and monitoring the lengths of several periods of inactivity at which the mobile radio network disconnects the IP connection;

means for determining a maximum interval between keep-alive messages such that the maximum interval meets a predetermined criterion of statistical confidence, based on the several monitored lengths of periods of inactivity; and

means for setting the interval between keep-alive messages to the maximum interval.