Flow control buffering

• US 20060114821A1
• Filed: 12/01/2004
• Published: 06/01/2006
• Est. Priority Date: 12/01/2004
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Plestid, Thomas Leonard Trevor, Willey, William Daniel, Islam, Muhammad Khaledul
• Granted Patent: US 7,529,184 B2
• Time in Patent Office: Days
• US Class Current: 370/229
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/266 Stopping or restarting the source, e.g. X-on or X-off
• CPC Class Codes: H04L 47/28 in relation to timing considerations
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints

Abstract

A method and system for improved buffering during a flow control event, the system comprising: a mobile station having a mobile timer; a radio network communicating wirelessly with the mobile station and including: a base station; and a packet control function (PCF) capable of interrupting the flow of data to the wireless device during the flow control event; a packet data serving node (PDSN) communicating with the PCF and having a buffer to store data received for the mobile station during the flow control event, the buffer having a buffer timer; and a push function communicating with the PDSN and having a retry timer to indicate when to resend an unacknowledged packet; wherein the system coordinates the buffer timer with either the mobile timer or the retry timer to eliminate redundant messages.

Claims

1. A method of improved buffering during a flow control event in a network having a push function, a packet data serving node (PDSN) having a buffer, a packet control function (PCF) and a mobile device, comprising the steps of:

coordinating a buffer timer for the buffer in the PDSN with a retry timer value from the push function.

sending a control message from the push function to the PDSN, the control message having the retry timer value; and

setting the buffer timer in the PDSN to discard packets older than the retry timer value during a flow control event.

2. The method of claim 1, wherein the coordinating step occurs at the establishment of a point to point protocol session or at a change in a point to point protocol session.

3. The method of claim 1, wherein the control message further includes a value for a maximum number of packets that can be transmitted before an acknowledgement is received.

4. The method of claim 1, wherein the control message includes information about an air interface used by the device.

5. The method of any of claims 1, wherein the control message includes an indication of the mobile device type.

6. The method of any of claims 1, wherein the PDSN ignores a flow control timer value received from the PCF.

7. The method of claim 1, further comprising the steps of:

receiving a buffer indicator from the PCF; and

overriding buffing if the buffer indicator tells the PDSN not to buffer.

8. The method of claim 1, wherein the setting step further comprises utilizing a source IP address to adjust the buffer timer.

9. The method of claim 1, wherein the setting step further comprises utilizing a protocol of a packet to adjust the buffer timer.

29. The system of claim 5 wherein coordinating occurs at establishment of a point to point protocol session.

10. A method of improved buffering during a flow control event in a network having a push function, a packet data serving node (PDSN) having a buffer, a packet control function (PCF) and a mobile device, comprising the steps of:

coordinating a buffer timer for the buffer in the PDSN with a mobile timer value from the mobile station, the coordinating step including;

sending a control message from the mobile station to the PDSN, the control message having the mobile timer value; and

setting the buffer timer in the PDSN to discard packets older than the mobile timer value during a flow control event.

11. The method of claim 10, wherein the mobile timer value is provisioned on the mobile station.

12. The method of claim 10, wherein the mobile timer value is received from the PDSN.

13. The method of claim 10, wherein the mobile timer value is received from the push function.

14. The method of claim 10, further comprising the steps of:

receiving a buffer indicator from the PCF; and

overriding buffing if the buffer indicator tells the PDSN not to buffer.

15. The method of claim 10, wherein the setting step further comprises utilizing a source IP address to adjust the buffer timer.

16. The method of any of claims 10, wherein the setting step further comprises utilizing a protocol of a packet to adjust the buffer timer.

17. The method of claim 10, wherein the buffer in the PDSN is a rolling buffer.

18. A method of improved buffering during a flow control event in a network having a push function, a packet data serving node (PDSN) having a buffer, a packet control function (PCF) and a mobile device, comprising the steps of:

coordinating a buffer timer for the buffer in the PDSN with a stored timer value from a database, the coordinating step including;

querying the database from the PDSN for the stored timer value; and

setting the buffer timer in the PDSN to discard packets older than the stored value during a flow control event.

19. The method of claim 18, wherein the database is part of the authorization and accounting (AAA) database.

20. The method of claim 18, wherein the database receives the stored timer values from the push function.

21. The method of any of claim 18, wherein the buffer in the PDSN is a rolling buffer.

22. A method of improved buffering during a flow control event in a network having a push function, a packet data serving node (PDSN), a packet control function (PCF) and a mobile device, comprising the steps of:

sending a control message from either the mobile station or the push function to the PDSN;

receiving a flow control event message from the PCF at the PDSN;

forwarding the buffer timer value from the PDSN to the push function; and

setting a retry timer at the push function to a value greater than the buffer timer value.

23. The method of claim 22, wherein the setting step delays the retry timer value based on a type of service for the mobile device.

24. The method of claim 22, wherein the setting step delays the retry timer value based on a processing delay of the mobile device.

25. A system for improved buffering during a flow control event, the system comprising:

a mobile station having a mobile timer;

a radio network communicating wirelessly with the mobile station and including;

a base station; and

a packet control function (PCF) capable of interrupting the flow of data to the wireless device during the flow control event;

a packet data serving node (PDSN) communicating with the PCF and having a buffer to store data received for the mobile station during the flow control event, the buffer having a buffer timer; and

a push function communicating with the PDSN and having a retry timer to indicate when to resend an unacknowledged packet;

wherein the system coordinates the buffer timer with either the mobile timer or the retry timer to eliminate redundant messages.

26. The system of claim 25, wherein the coordination includes a control message being sent to the PDSN including a value for the mobile timer or the retry timer, and wherein the buffer timer in the PDSN is set to discard packets older than the retry timer value during a flow control event.

27. The system of claim 25, wherein the control message is sent from the push function.

28. The system of claim 25, wherein the control message is sent from the mobile device.

30. The system of claim 25, wherein the coordination of the buffer timer includes adjusting the buffer timer based on an IP source address of a packet from the push function.

31. The system of claim 25, wherein the coordination of the buffer timer includes adjusting the buffer timer based on a protocol of a packet from the push function.

32. The system of claim 25, wherein coordinating includes:

sending a control message to the PDSN;

receiving a flow control event message from the PCF at the PDSN;

forwarding a buffer timer value at the PDSN to the push function; and

setting the retry timer to a value greater than the buffer timer value.

33. The system of claim 32, wherein the control message is sent from the push function.

34. The system of claim 32, wherein the control message is sent from the mobile device.

35. The system of claim 25, further comprising:

a database, the database having retry timer values for a mobile device, wherein the PDSN queries the database for the retry timer value and sets the buffer timer to discard data older than the retry timer value from the buffer during a flow control event.