Fragmenting Large Packets in the Presence of High Priority Packets

• US 20080170553A1
• Filed: 01/14/2008
• Published: 07/17/2008
• Est. Priority Date: 01/15/2007
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Durand, Roger, Montemurro, Michael
• Granted Patent: US 8,619,731 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/24 Traffic characterised by specific attributes, e.g. priority or QoS
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 28/065 using assembly or disassembly of packets
• CPC Class Codes: H04W 72/569 of the traffic information
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

In the presence of high priority traffic received at a mobile station over a wireless medium or to be transmitted by the mobile station over the wireless medium, a fragmentation threshold in a wireless local area network (WLAN) medium access control (MAC) layer of the mobile station is adjusted according to a highest priority of the traffic. Packets received by the WLAN MAC layer are fragmented into packets each of which is no larger than the fragmentation threshold.

Claims

1. A method for controlling transmission of traffic from a mobile station over a wireless medium, the method comprising:

in the presence of high priority traffic received at the mobile station over the wireless medium or to be transmitted by the mobile station over the wireless medium, adjusting a fragmentation threshold in a wireless local area network (WLAN) medium access control (MAC) layer of the mobile station according to a highest priority of the traffic; and

fragmenting packets received by the WLAN MAC layer that are larger than the fragmentation threshold into packets each of which is no larger than the fragmentation threshold.

2. The method of claim 1, further comprising:

monitoring a stream control application in the mobile station to determine whether the high priority traffic is present.

3. The method of claim 2, wherein monitoring the stream control application comprises:

identifying that an admission control request for the high priority traffic is to be transmitted by the mobile station over the wireless medium to an access point.

4. The method of claim 2, wherein monitoring the stream control application comprises:

identifying that a traffic specification for the high priority traffic has either expired or been explicitly terminated by an access point.

5. The method of claim 2, wherein monitoring the stream control application comprises:

identifying that for at least a certain period of time, the packets lack an indication of a type of service corresponding to the high priority traffic.

6. The method of claim 2, further comprising:

monitoring the stream control application to determine an expected packet size of the high priority traffic having the highest priority.

7. The method of claim 6, wherein monitoring the stream control application to determine the expected packet size comprises:

extracting the expected packet size from a traffic specification in an admission control request for the high priority traffic that is to be transmitted by the mobile station over the wireless medium to an access point.

8. The method of claim 1, wherein the fragmentation threshold is slightly larger than the expected packet size.

9. The method of claim 1, wherein the high priority traffic comprises voice traffic.

10. The method of claim 1, wherein the high priority traffic comprises real-time video traffic.

11. The method of claim 1, wherein the high priority traffic having the highest priority is video traffic.

12. The method of claim 1, wherein the packets received by the MAC layer comprise best effort traffic.

13. The method of claim 1, wherein the packets received by the MAC layer comprise background traffic.

14. A method for controlling transmission of traffic from a mobile station over a wireless medium, the method comprising:

defining one or more fragmentation thresholds corresponding to different types of media streams;

detecting the type of media stream of the highest priority media stream session involving the mobile station and currently established over the wireless medium;

setting a fragmentation threshold in a wireless local area network (WLAN) medium access control (MAC) layer of the mobile station to the fragmentation threshold corresponding to the detected type; and

fragmenting packets received by the MAC layer that are larger than the fragmentation threshold into packets each of which is no larger than the fragmentation threshold.

15. The method of claim 14, further comprising:

in the absence of any media stream sessions involving the mobile station and currently established over the wireless medium, setting the fragmentation threshold in the WLAN MAC layer to a fragmentation threshold that is higher than any of the fragmentation thresholds corresponding to different types of media streams.

16. The method of claim 14, wherein different fragmentation thresholds are defined for different types of video media streams having different maximum packet sizes.

17. A method for controlling transmission of traffic from a mobile station over a wireless medium, the method comprising:

defining one or more fragmentation thresholds corresponding to different priorities of media streams;

detecting the setup and priority of the highest priority media stream session involving the mobile station and currently established over the wireless medium;

setting a fragmentation threshold in a wireless local area network (WLAN) medium access control (MAC) layer of the mobile station to the fragmentation threshold corresponding to the detected priority; and

fragmenting packets received by the MAC layer that are larger than the fragmentation threshold into packets each of which is no larger than the fragmentation threshold.

18. The method of claim 17, further comprising:

in the absence of any media stream sessions involving the mobile station and currently established over the wireless medium, setting the fragmentation threshold in the WLAN MAC layer to a fragmentation threshold that is higher than any of the fragmentation thresholds corresponding to different priorities of media streams.

19. A mobile station comprising:

a wireless local area network (WLAN) interface comprising a medium access control (MAC) layer and a physical (PHY) layer, through which the mobile station is able to receive and transmit over a wireless medium;

a processor coupled to the WLAN interface; and

a memory coupled to the processor, the memory able to store a stream control application and a stream control monitor which, when executed by the processor, adjusts, in the presence of high priority traffic received at the mobile station over the wireless medium or to be transmitted by the mobile station over the wireless medium, a fragmentation threshold in the WLAN MAC layer according to a highest priority of the traffic,

wherein the WLAN MAC layer is able to fragment packets received thereby that are larger than the fragmentation threshold into packets each of which is no larger than the fragmentation threshold.

20. A computer-readable medium having stored thereon instructions which, when executed by a processor of a mobile station, result in:

defining one or more fragmentation thresholds corresponding to different priorities of media streams;

detecting the setup and priority of the highest priority media stream session involving the mobile station and currently established over a wireless medium;

setting a fragmentation threshold in a wireless local area network (WLAN) medium access control (MAC) layer of the mobile station to the fragmentation threshold corresponding to the detected priority; and

fragmenting packets received by the MAC layer that are larger than the fragmentation threshold into packets each of which is no larger than the fragmentation threshold.