Packet transmission time in 802.11

From
Revision as of 13:12, 8 March 2007 by Ofriedri (talk | contribs) (added link to the transmission time EXCEL file for personalized calculation)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

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.