Method and apparatus for segmenting a data packet
View Patent ↗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.
1. 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.
2. The method in claim 1 , wherein the first segment size is smaller than a maximum allowed segment size.
3. The method in claim 1 , wherein the higher priority traffic is multiplexed with the segments over communications channel.
4. The method in claim 1 , wherein the higher priority traffic and the segments are transmitted over a multilink channel.
5. The method in claim 1 , wherein all of the data packet segments except the last segment are the first segment size.
6. The method in claim 5 , wherein the last segment is the same size as or larger than the first segment size.
7. The method in claim 1 , wherein the first segment size is less than the second segment size.
8. The method in claim 1 , 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.
9. The method in claim 1 , further comprising:
determining a number of segments “n” for the data packet based on the packet size “P” and a predetermined segment size “MSS”.
10. The method in claim 9 , 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.
11. The method in claim 9 , 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.
12. The method in claim 9 , wherein the size S(i) of each segment is determined as using a second approach as follows:
S
(
i
)
=
{
if
1
≤
i
≤
n
-
2
then
ceil
[
P
-
MSS
n
-
1
]
if
i
=
n
-
1
then
P
-
(
n
-
2
)
·
ceil
[
P
-
MSS
n
-
1
]
if
i
=
n
then
MSS
,
where ceil[ ] denotes rounding to a next larger integer.
13. 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,
wherein the first segment size is smaller than a maximum allowed segment size.
14. The apparatus in claim 13 , wherein the means for transmitting multiplexes the higher priority traffic with the segments over communications channel.
15. The apparatus in claim 13 , wherein the means for transmitting transmits the higher priority traffic and the segments over a multilink channel.
16. The apparatus in claim 13 , wherein all of the data packet segments except the last segment are the first segment size.
17. The apparatus in claim 16 , wherein the last segment is the same size as or larger than the first segment size.
18. The apparatus in claim 13 , wherein the first segment size is less than the second segment size.
19. The apparatus in claim 13 , 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.
20. The apparatus in claim 13 , 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”.
21. The apparatus in claim 20 , 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.
22. The apparatus in claim 20 , 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.
23. The apparatus in claim 20 , wherein the size S(i) of each segment is determined as using a second approach as follows:
S
(
i
)
=
{
if
1
≤
i
≤
n
-
2
then
ceil
[
P
-
MSS
n
-
1
]
if
i
=
n
-
1
then
P
-
(
n
-
2
)
·
ceil
[
P
-
MSS
n
-
1
]
if
i
=
n
then
MSS
,
where ceil[ ] denotes rounding to a next larger integer.
24. Apparatus for use in transmitting a data packet at a first priority level along with traffic from a second, higher priority level, comprising:
electronic circuitry configured to:
determine a size of the data packet;
determine 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; and
segment 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
a transmitter for transmitting the higher priority traffic along with the data packet segments,
wherein the first segment size is smaller than a maximum allowed segment size.
25. The apparatus in claim 24 , wherein the transmitter is configured to multiplex the higher priority traffic with the segments over communications channel.
26. The apparatus in claim 24 , wherein the transmitter is configured to transmit the higher priority traffic and the segments over a multilink channel.
27. The apparatus in claim 24 , wherein all of the data packet segments except the last segment are the first segment size.
28. The apparatus in claim 27 , wherein the last segment is the same size as or larger than the first segment size.
29. The apparatus in claim 24 , wherein the first segment size is less than the second segment size.
30. The apparatus in claim 24 , wherein there are three or more traffic priority levels, and for each at least two of the traffic priority levels the electronic circuitry is configured to:
determine a maximum segment size for a data packet at the traffic priority level;
determine a size of the data packet;
determine a first segment size for the data packet and a second segment size for the data packet using the determined maximum segment size; and
segment 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,
wherein the transmitter is configured to transmit the higher priority traffic along with the data packet segments.
31. The apparatus in claim 24 , wherein the electronic circuitry is configured to determine a number of segments “n” for the data packet based on the packet size “P” and a predetermined segment size “MSS”.
32. The apparatus in claim 31 , 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.
33. The apparatus in claim 31 , 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.
34. The apparatus in claim 31 , wherein the size S(i) of each segment is determined as using a second approach as follows:
S
(
i
)
=
{
if
1
≤
i
≤
n
-
2
then
ceil
[
P
-
MSS
n
-
1
]
if
i
=
n
-
1
then
P
-
(
n
-
2
)
·
ceil
[
P
-
MSS
n
-
1
]
if
i
=
n
then
MSS
,
where ceil[ ] denotes rounding to a next larger integer.