Packet transmission time in 802.11: Difference between revisions

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(added tables for 802.11g and fixed some small errors)
(added link to the transmission time EXCEL file for personalized calculation)
 
(2 intermediate revisions by the same user not shown)
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== Frame exchange duration for a unicast data frame and the acknowledgement frame ==
== Frame exchange duration for a unicast data frame and the acknowledgement frame ==


To download an editable EXCEL sheet, where you can enter your personal values, click on the following link:
⚫
==== For 802.11b bitrates (valid in 802.11b and g; short headers used) ====
[[Image:80211_TransmissionTime.xls]].

There you can enter the length of the data packet as well as a few other options to calculate the expected transmission time. Also see the comments in the file. The MAKRO inside the file allows to create wiki output; just deactivate it in case you don't need it.


⚫
=== For 802.11b bitrates (valid in 802.11a*,b and g; short headers used) ===


{| {{prettytable}} <hiddentext>generated with [[:de:Wikipedia:Textverarbeitung/EXCEL-Tabellenumwandlung]] V14<\hiddentext>
{| {{prettytable}} <hiddentext>generated with [[:de:Wikipedia:Textverarbeitung/EXCEL-Tabellenumwandlung]] V14<\hiddentext>
|- valign="bottom"
|- valign="bottom"
| width="15,75" Height="12,75" | o
| width="15,75" Height="12,75" |
| width="244,5" | Payload in bytes:
| width="244,5" | Payload in bytes:
|style="background-color:#99CC00" width="30" align="center" | 1500
|style="background-color:#99CC00" width="30" align="center" | 1500
Line 49: Line 55:
|
|
|style="background-color:#CCFFCC" |
|style="background-color:#CCFFCC" |
|style="background-color:#CCFFCC" align="center" | 1<BR>Mbps
|style="background-color:#CCFFCC" align="center" | 1 <BR>Mbps
|style="background-color:#CCFFCC" |
|style="background-color:#CCFFCC" |
|
|
|style="background-color:#CCFFCC;font-weight:bold" align="center" |
|style="background-color:#CCFFCC;font-weight:bold" align="center" |
|style="background-color:#CCFFCC" align="center" | 2<BR>Mbps
|style="background-color:#CCFFCC" align="center" | 2 <BR>Mbps
|style="background-color:#CCFFCC" align="center" |
|style="background-color:#CCFFCC" align="center" |
|
|
Line 327: Line 333:
| Height="12,75" |
| Height="12,75" |
| Basic rate set minimal (6, 12, 24 Mbps):
| Basic rate set minimal (6, 12, 24 Mbps):
| align="center" | no
| align="center" | yes
|
|
| align="center" |
| align="center" |
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|
|
|style="background-color:#CCFFCC" align="right" |
|style="background-color:#CCFFCC" align="right" |
|style="background-color:#CCFFCC" align="center" | 6<BR>Mbps
|style="background-color:#CCFFCC" align="center" | 6 <BR>Mbps
|style="background-color:#CCFFCC" |
|style="background-color:#CCFFCC" |
|
|
|style="background-color:#CCFFCC;font-weight:bold" align="center" |
|style="background-color:#CCFFCC;font-weight:bold" align="center" |
|style="background-color:#CCFFCC" align="center" | 9<BR>Mbps
|style="background-color:#CCFFCC" align="center" | 9 <BR>Mbps
|style="background-color:#CCFFCC" align="center" |
|style="background-color:#CCFFCC" align="center" |
|
|
Line 572: Line 578:
| align="right" | 24
| align="right" | 24
|
|
| align="center" | 9
| align="center" | 6
| align="center" | 134
| align="center" | 134
| align="right" | 16
| align="right" | 24
|
|
| align="center" | 12
| align="center" | 12
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| align="right" | 12
| align="right" | 12
|
|
| align="center" | 18
| align="center" | 12
| align="center" | 134
| align="center" | 134
| align="right" | 8
| align="right" | 12


|- valign="bottom"
|- valign="bottom"
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|style="font-weight:bold" |
|style="font-weight:bold" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="right" | 52
|style="font-weight:bold" align="right" | 60
|
|
|style="font-weight:bold" align="right" |
|style="font-weight:bold" align="right" |
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|style="font-weight:bold" |
|style="font-weight:bold" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="right" | 44
|style="font-weight:bold" align="right" | 48


|- valign="bottom"
|- valign="bottom"
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|style="font-weight:bold" |
|style="font-weight:bold" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="center" |
|style="background-color:#99CC00;font-weight:bold" align="right" | 1470
|style="background-color:#99CC00;font-weight:bold" align="right" | 1478
|
|
|style="font-weight:bold" align="right" |
|style="font-weight:bold" align="right" |
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|style="font-weight:bold" |
|style="font-weight:bold" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="center" |
|style="background-color:#99CC00;font-weight:bold" align="right" | 782
|style="background-color:#99CC00;font-weight:bold" align="right" | 786


|- valign="bottom"
|- valign="bottom"
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|- valign="bottom"
|- valign="bottom"
| Height="12,75" |
| Height="12,75" |
| Data transmission bitrate (802.11g):
| Data transmission bitrate (802.11g / a*):
|
|
|style="background-color:#CCFFCC" align="right" |
|style="background-color:#CCFFCC" align="right" |
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| align="right" | 8
| align="right" | 8
|
|
| align="center" | 36
| align="center" | 24
| align="center" | 134
| align="center" | 134
| align="right" | 4
| align="right" | 8
|
|
| align="center" | 48
| align="center" | 24
| align="center" | 134
| align="center" | 134
| align="right" | 4
| align="right" | 8
|
|
| align="center" | 54
| align="center" | 24
| align="center" | 134
| align="center" | 134
| align="right" | 4
| align="right" | 8


|- valign="bottom"
|- valign="bottom"
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|style="font-weight:bold" |
|style="font-weight:bold" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="right" | 40
|style="font-weight:bold" align="right" | 44
|
|
|style="font-weight:bold" align="right" |
|style="font-weight:bold" align="right" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="right" | 40
|style="font-weight:bold" align="right" | 44
|
|
|style="font-weight:bold" |
|style="font-weight:bold" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="right" | 40
|style="font-weight:bold" align="right" | 44


|- valign="bottom"
|- valign="bottom"
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|style="font-weight:bold" |
|style="font-weight:bold" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="center" |
|style="background-color:#99CC00;font-weight:bold" align="right" | 438
|style="background-color:#99CC00;font-weight:bold" align="right" | 442
|
|
|style="font-weight:bold" align="right" |
|style="font-weight:bold" align="right" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="center" |
|style="background-color:#99CC00;font-weight:bold" align="right" | 350
|style="background-color:#99CC00;font-weight:bold" align="right" | 354
|
|
|style="font-weight:bold" |
|style="font-weight:bold" |
|style="font-weight:bold" align="center" |
|style="font-weight:bold" align="center" |
|style="background-color:#99CC00;font-weight:bold" align="right" | 322
|style="background-color:#99CC00;font-weight:bold" align="right" | 326


|}
|}


.*) valid for 802.11a with the following change: No signal extension time, SIFS is 16μs instead of 10μs and DIFS should be 34μs instead of 28μs. The overall transmission time stays the same.

Latest revision as of 11:12, 8 March 2007

Frame exchange duration for a unicast data frame and the acknowledgement frame

To download an editable EXCEL sheet, where you can enter your personal values, click on the following link: File:80211 TransmissionTime.xls.

There you can enter the length of the data packet as well as a few other options to calculate the expected transmission time. Also see the comments in the file. The MAKRO inside the file allows to create wiki output; just deactivate it in case you don't need it.


For 802.11b bitrates (valid in 802.11a*,b and g; short headers used)

Payload in bytes: 1500
Short preamble and headers (DSSS): yes
Data transmission bitrate (802.11b/g): 1
Mbps 		2
Mbps 		5,5 Mbps 11 Mbps
Bitrate (Mbit/s) Length (bits) Time (μs) Bitrate (Mbit/s) Length (bits) Time (μs) Bitrate (Mbit/s) Length (bits) Time (μs) Bitrate (Mbit/s) Length (bits) Time (μs)
DIFS 50 50 50 50
D PHY header: PLCP preamble 1 144 144 1 72 72 1 72 72 1 72 72
A PHY header: PLCP header 1 48 48 2 48 24 2 48 24 2 48 24
T MAC headers (28 bytes) + MAC body 1 12224 12224 2 12224 6112 5,5 12224 2223 11 12224 1111
A tx time data: 12466 6258 2369 1257
SIFS 10 10 10 10
A PHY header: PLCP preamble 1 144 144 1 72 72 1 72 72 1 72 72
C PHY header: PLCP header 1 48 48 2 48 24 2 48 24 2 48 24
K MAC headers (28 bytes), no MAC body 1 112 112 2 112 56 5,5 112 21 11 112 11
tx time ack: 314 162 127 117
tx time data + ack: 12780 6420 2496 1374
Basic rate set minimal (6, 12, 24 Mbps): yes
Data transmission bitrate (802.11g / a*): 6
Mbps 		9
Mbps 		12 Mbps 18 Mbps
Bitrate (Mbit/s) Length (bits) Time (μs) Bitrate (Mbit/s) Length (bits) Time (μs) Bitrate (Mbit/s) Length (bits) Time (μs) Bitrate (Mbit/s) Length (bits) Time (μs)
DIFS 28 28 28 28
D PHY header: PLCP preamble - - 16 - - 16 - - 16 - - 16
A PHY header: PLCP header 6 24 4 6 24 4 6 24 4 6 24 4
T MAC headers + MAC body + PHY pad 6 12246 2044 9 12246 1364 12 12246 1024 18 12246 684
A signal extension time 6 6 6 6
tx time data: 2098 1418 1078 738
SIFS 10 10 10 10
A PHY header: PLCP preamble - - 16 - - 16 - - 16 - - 16
C PHY header: PLCP header 6 24 4 6 24 4 6 24 4 6 24 4
K MAC headers 6 134 24 6 134 24 12 134 12 12 134 12
signal extension time 6 6 6 6
tx time ack: 60 60 48 48
tx time data + ack: 2158 1478 1126 786
Data transmission bitrate (802.11g / a*): 24 Mbps 36 Mbps 48 Mbps 54 Mbps
Bitrate (Mbit/s) Length (bits) Time (μs) Bitrate (Mbit/s) Length (bits) Time (μs) Bitrate (Mbit/s) Length (bits) Time (μs) Bitrate (Mbit/s) Length (bits) Time (μs)
DIFS 28 28 28 28
D PHY header: PLCP preamble - - 16 - - 16 - - 16 - - 16
A PHY header: PLCP header 6 24 4 6 24 4 6 24 4 6 24 4
T MAC headers (28 bytes) + MAC body 24 12246 512 36 12246 344 48 12246 256 54 12246 228
A signal extension time 6 6 6 6
tx time data: 566 398 310 282
SIFS 10 10 10 10
A PHY header: PLCP preamble - - 16 - - 16 - - 16 - - 16
C PHY header: PLCP header 6 24 4 6 24 4 6 24 4 6 24 4
K MAC headers + PHY pad 24 134 8 24 134 8 24 134 8 24 134 8
signal extension time 6 6 6 6
tx time ack: 44 44 44 44
tx time data + ack: 610 442 354 326


.*) valid for 802.11a with the following change: No signal extension time, SIFS is 16μs instead of 10μs and DIFS should be 34μs instead of 28μs. The overall transmission time stays the same.

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