Method and apparatus for segmenting a data packet

• US 20030110286A1
• Filed: 12/12/2001
• Published: 06/12/2003
• Est. Priority Date: 12/12/2001
• Status: Active Grant

• Current Assignee: Optis Cellular Technology LLC (Brevet Capital)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Toth, Gabor, Henriques, Bengt, Antal, Csaba
• Granted Patent: US 7,224,703 B2
• Time in Patent Office: Days
• US Class Current: 709/236
• CPC Class Codes: H04L 12/6418 Hybrid transport
• CPC Class Codes: H04L 2012/6459 Multiplexing, e.g. TDMA, CDMA
• CPC Class Codes: H04L 47/2408 for supporting different services, e.g. a differentiated services [DiffServ] type of service
• CPC Class Codes: H04L 47/36 by determining packet size, e.g. maximum transfer unit [MTU]
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/6215 Individual queue per QOS, rate or priority

Abstract

The efficiency of transmitting lower priority data traffic along with higher priority traffic is improved by segmenting a data packet in such a way so as to reduce transmission delay of the higher priority traffic. The data packet is segmented so that all its segments, including the last segment, are approximately the same size. The segment size is set smaller than a maximum permitted segment size. Indeed, it is desirable (though not necessary) to set the segment size as small as design parameters, (e.g., minimize segment header overhead), allow in order to reduce transmission delay of the higher priority traffic. Because the last segment is set at the same size or a larger size than the other segments, delay in transmitting the data packet is also reduced. The last segment may be sized as large as practical to minimize the transmission delay of the data packet. Once segmented, the data packet segments are transmitted along with the higher priority traffic.

Claims

8. A method for segmenting a data packet, where the data packet segments are transmitted along with higher priority traffic, comprising:

segmenting the data packet so that all the packet'"'"'s segments, including the last segment, have approximately the same size.

9. The method in claim 8, wherein the last segment is the same size as or the largest of all the segments.

10. The method in claim 8, wherein the segment size is smaller than a maximum size permitted in order to reduce transmission delay of the higher priority traffic.

11. The method in claim 8, wherein the segment size is reduced without increasing a number of data packet segments.

12. The method in claim 8, wherein the last segment is as large as possible given other design constraints.

13. The method in claim 8, further comprising:

transmitting the data packet segments along with the higher priority traffic.

14. A method for use in transmitting a data packet at a first priority level along with traffic from a second, higher priority level, comprising:

determining a size of the data packet;

determining a first segment size for the data packet and a second segment size for the data packet, where the first and second segment sizes are determined to reduce a delay either in transmitting the higher priority traffic or in transmitting the data packet;

segmenting the data packet into plural segments at the first segment size and a last segment of the data packet at the second segment size; and

transmitting the higher priority traffic along with the data packet segments.

15. The method in claim 14, wherein the first segment size is smaller than a maximum allowed segment size.

16. The method in claim 14, wherein the higher priority traffic is multiplexed with the segments over communications channel.

17. The method in claim 14, wherein the higher priority traffic and the segments are transmitted over a multilink channel.

18. The method in claim 14, wherein all of the data packet segments except the last segment are the first segment size.

19. The method in claim 18, wherein the last segment is the same size as or larger than the first segment size.

20. The method in claim 14, wherein the first segment size is less than the second segment size.

21. The method in claim 14, wherein there are three or more traffic priority levels, and for each at least two of the traffic priority levels the method comprises:

determining a maximum segment size for a data packet at the traffic priority level;

determining a size of the data packet;

determining a first segment size for the data packet and a second segment size for the data packet using the determined maximum segment size;

segmenting the data packet into plural segments at the first segment size and a last segment of the data packet at the second segment size, where the first and second segment sizes are determined to reduce a delay either in transmitting the higher priority traffic or in transmitting the data packet; and

transmitting the higher priority traffic along with the data packet segments.

22. The method in claim 14, further comprising:

determining a number of segments “

n”

for the data packet based on the packet size “

P” and

a predetermined segment size “

MSS”

.

23. The method in claim 22, wherein the first segment size equals P/n, and wherein if P/n equals a first integer and a remainder, the segment size equals a second integer rounded up from the first integer.

24. The method in claim 22, wherein the second segment size is P/n, and wherein if P/n equals an integer and a remainder, the second segment size equals the integer.

25-1. The apparatus in claim 26, wherein all of the segments have approximately the same size.

26. Apparatus for use in transmitting a data packet along with higher priority traffic, comprising:

electronic circuitry configured to segment the data packet to reduce transmission delay of the higher priority traffic, and

a transmitter for transmitting the data packet segments with the higher priority traffic.

1. A method for use in transmitting a data packet along with higher priority traffic, comprising:

segmenting the data packet to reduce transmission delay of the higher priority traffic, and

transmitting the data packet segments with the higher priority traffic.

2. The method in claim 1, wherein all of the segments have approximately the same size.

3. The method of claim 1, wherein the segment size is made smaller than a maximum size permitted.

4. The method in claim 1, wherein the segment size is as small as design parameters allow without increasing a number of the data packet segments.

5. The method in claim 1, wherein the last segment is the same size or larger than of all the other segments.

6. The method in claim 1, wherein the last segment is as large as possible given other design constraints.

7. The method in claim 1, further comprising:

using a multilink or other multiplexing protocol to transmit the data packet segments along with the higher priority traffic over a channel.

25. The method in claim 22, wherein the size S(i) of each segment is determined as using a second approach as follows:

27. The apparatus in claim 26, wherein the segment size is made smaller than a maximum size permitted.

28. The apparatus in claim 26, wherein the segment size is as small as design parameters allow.

29. The apparatus in claim 26, wherein the last segment is the same size or larger than of all the other segments.

30. The apparatus in claim 26, wherein the last segment is as large as possible given the other design constraints.

31. The apparatus in claim 26, wherein the transmitter is configured to use a multilink or other multiplexing protocol to transmit the data packet segments along with the higher priority traffic over a channel.

32. Apparatus for use in transmitting a data packet at a first priority level along with traffic from a second, higher priority level, comprising:

means for determining a size of the data packet;

means for determining a first segment size for the data packet and a second segment size for the data packet, where the first and second segment sizes are determined to reduce a delay either in transmitting the higher priority traffic or in transmitting the data packet;

means for segmenting the data packet into plural segments at the first segment size and a last segment of the data packet at the second segment size; and

means for transmitting the higher priority traffic along with the data packet segments.

33. The apparatus in claim 32, wherein the first segment size is smaller than a maximum allowed segment size.

34. The apparatus in claim 32, wherein the means for transmitting multiplexes the higher priority traffic with the segments over communications channel.

35. The apparatus in claim 32, wherein the means for transmitting transmits the higher priority traffic and the segments over a multilink channel.

36. The apparatus in claim 32, wherein all of the data packet segments except the last segment are the first segment size.

37. The apparatus in claim 36, wherein the last segment is the same size as or larger than the first segment size.

38. The apparatus in claim 32, wherein the first segment size is less than the second segment size.

39. The apparatus in claim 32, wherein there are three or more traffic priority levels, and for each at least two of the traffic priority levels the apparatus comprises:

means for determining a maximum segment size for a data packet at the traffic priority level;

means for determining a size of the data packet;

means for determining a first segment size for the data packet and a second segment size for the data packet using the determined maximum segment size;

means for segmenting the data packet into plural segments at the first segment size and a last segment of the data packet at the second segment size, where the first and second segment sizes are determined to reduce a delay either in transmitting the higher priority traffic or in transmitting the data packet; and

means for transmitting the higher priority traffic along with the data packet segments.

40. The apparatus in claim 32, further comprising:

means for determining a number of segments “

n”

for the data packet based on the packet size “

P” and

a predetermined segment size “

MSS”

.

41. The apparatus in claim 40, wherein the first segment size equals P/n, and wherein if P/n equals a first integer and a remainder, the segment size equals a second integer rounded up from the first integer.

42. The apparatus in claim 40, wherein the second segment size is P/n, and wherein if P/n equals an integer and a remainder, the second segment size equals the integer.

43. The apparatus in claim 40, wherein the size S(i) of each segment is determined as using a second approach as follows: