From: Simon Barber <simon-vp0mx6+5gkqFX2APIN6yfw@public.gmane.org>
To: "radiotap-sUITvd46vNxg9hUCZPvPmw@public.gmane.org"
<radiotap-sUITvd46vNxg9hUCZPvPmw@public.gmane.org>
Cc: thomas-W/OLz77bvjtBDgjK7y7TUQ@public.gmane.org
Subject: TSFT
Date: Fri, 16 Nov 2012 22:26:31 -0800 [thread overview]
Message-ID: <50A72E17.6070207@superduper.net> (raw)
This is the current definition of TSFT:
"Value in microseconds of the MAC's 64-bit 802.11 Time Synchronization
Function timer when the first bit of the MPDU arrived at the MAC. For
received frames only."
My experience with TSFT is with Atheros cards, which record the
timestamp at the end of the frame, not the start.
Do you know the behaivour of any particular capture systems re: TSFT -
where do they timestamp the frame?
Furthermore for DSSS/CCK the definition above is reasonable, but for
OFDM and HT (802.11n) the SIGNAL field (part of the PLCP header, not
part of the MPDU) is part of the first data symbol. It would be much
clearer to change the definition to state that the timestamp is at the
start of this first SIGNAL/data symbol. Any objections to doing this, or
preference to change the reference point to a different part of the frame?
In my wireshark patch I've added options to interpret TSFT as the start
of end of the frame.
Simon
next reply other threads:[~2012-11-17 6:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-17 6:26 Simon Barber [this message]
[not found] ` <50A72E17.6070207-vp0mx6+5gkqFX2APIN6yfw@public.gmane.org>
2012-11-17 6:48 ` TSFT David Young
[not found] ` <20121117064848.GO21779-Gq8g4XVd89tWk0Htik3J/w@public.gmane.org>
2012-11-17 8:45 ` TSFT Johannes Berg
[not found] ` <1353141950.9543.3.camel-8Nb76shvtaUJvtFkdXX2HixXY32XiHfO@public.gmane.org>
2012-11-17 17:46 ` TSFT David Young
[not found] ` <20121117174600.GQ21779-Gq8g4XVd89tWk0Htik3J/w@public.gmane.org>
2012-11-17 18:43 ` TSFT Johannes Berg
2012-11-17 18:56 ` TSFT Guy Harris
2012-11-17 23:26 ` TSFT Thomas Pedersen
2012-11-18 7:20 ` TSFT Simon Barber
[not found] ` <50A88C3D.5030809-vp0mx6+5gkqFX2APIN6yfw@public.gmane.org>
2012-11-18 11:07 ` TSFT Johannes Berg
[not found] ` <1353236845.9649.6.camel-8Nb76shvtaUJvtFkdXX2HixXY32XiHfO@public.gmane.org>
2012-11-20 22:43 ` TSFT Simon Barber
[not found] ` <50AC0791.3040005-vp0mx6+5gkqFX2APIN6yfw@public.gmane.org>
2012-11-21 10:42 ` TSFT Johannes Berg
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