Electronic device and base station for maintaining a network connection

• US 7,720,989 B2
• Filed: 08/08/2008
• Issued: 05/18/2010
• Est. Priority Date: 02/25/2004
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Dunk, Craig Allan
• Primary Examiner(s): Duong; Oanh
• Application Number:
  US12/188,570
• Publication Number:
  US 20090210485A1
• Time in Patent Office: 648 Days
• Field of Search: 709/223, 709/224, 709/227, 709/232, 709/250, 714/55
• US Class Current: 709/232
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066

Abstract

An electronic device and wireless base station for maintaining a persistent connection is provided. In an embodiment, a system includes an electronic device that connects to a web-server via a physical link that is bandwidth-constrained. The physical link also includes a wireless base station and at least one network address translation (“NAT”) router that is configured to terminate idle connections between the client and the web-server. One of the electronic device and the wireless base station is configured to send keep-alive packets to the web-server in order to reduce the likelihood of the NAT router terminating the connection. The keep-alive packets are sent on a variable basis that is intended to reduce bandwidth consumption while ensuring that the NAT router does not deem the connection idle and terminate the connection.

Claims

1. An electronic device for maintaining a persistent connection, the electronic device comprising:

a network interface for communicating with another device via a network connection carried over a physical link that includes an equipment for terminating said network connection if said network connection remains idle for a predetermined time-out criterion of said equipment; and

a processor configured to;

send keep-alive signals on said network connection at a plurality of different time intervals; and

determine said predetermined time-out criterion of said equipment by;

loading an initial default time period;

sending at least one of said keep-alive signals to said another device at said initial default time period;

increasing said initial default time period if said initial default time period does not cause said network connection to be dropped by said equipment;

repeating said sending step and increasing step until said increased initial default time period causes said network connection to be dropped;

maintaining a last-known good time period when said increased initial default time period causes said network connection to be dropped, wherein said last-known good time period is less than and closest to said increased initial default time period that causes said network connection to be dropped;

reestablishing said network connection; and

thereafter,

sending subsequent keep-alive signals to said another electronic device at said last-known good time period.

2. The electronic device of claim 1, further configured to determine when one of said time intervals results in said equipment terminating said connection thereby determining said predetermined time-out criterion of said equipment.

3. The electronic device of claim 2, further configured to request an HTTP (Hyper Text Transfer Protocol) webpage via said connection of said another device and said keep-alive signal is a no-op signal.

4. The electronic device of claim 1, wherein said equipment is a NAT (Network Address Translator) router.

5. The electronic device of claim 1, wherein said predetermined time-out criterion is a predetermined time period.

6. The electronic device of claim 1, further comprising a client, said another device is a web-server and at least a portion of said link includes the Internet.

7. The electronic device of claim 6, wherein said client is battery operated and said initial default time period are increased more quickly as said battery life is depleted to thereby reduce battery consumption while determining said predetermined time-out criterion.

8. The electronic device of claim 7, wherein said client is a wireless device and at least a portion of said link includes a wireless connection from said wireless device to the Internet.

9. The base station of claim 1, wherein at least a portion of said link includes the Internet.

10. The bases station of claim 9, wherein at least a portion of said link includes a wireless connection from said electronic device to the Internet.

11. A system for maintaining a persistent connection between a electronic device and another device, the electronic device including a network interface for communicating with the another device via a network connection carried over a physical link between a base station and equipment for terminating said network connection if said network connection remains idle for a predetermined time-out criterion of said equipment, the system comprising:

the base station configured to;

send keep-alive signals on said network connection at a plurality of different time intervals; and

determine said predetermined time-out criterion of said equipment by;

loading an initial default time period;

sending at least one of said keep-alive signals to said another device at said initial default time period;

increasing said initial default time period if said initial default time period does not cause said network connection to be dropped by said equipment;

repeating said sending step and increasing step until said increased initial default time period causes said network connection to be dropped;

maintaining a last-known good time period when said increased initial default time period causes said network connection to be dropped, wherein said last-known good time period is less than and closest to said increased initial default time period that causes said network connection to be dropped;

reestablishing said network connection; and

thereafter,

sending subsequent keep-alive signals to the another electronic device at said last-known good time period.

12. The base station of claim 11, further configured to determine when one of said time intervals results in said equipment terminating said connection thereby determining said predetermined time-out criterion of said equipment.

13. The base station of claim 12, wherein said keep-alive signal is a no-op signal.

14. The base station of claim 11, wherein said equipment is a NAT (Network Address Translator) router.

15. The base station of claim 11, wherein said predetermined time-out criterion is a predetermined time period.