Re: IBSS issues

["Alina Friedrichsen" <x-alina@gmx.net>]

Hello!

> Yes, the TBTT is calculated only once after joining the BSS network.

What about the following, which is called after scanning?
ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED);

This calls indirectly the function which looks in the template for the =
TSF.

> Am not sure I understand the proposal. What would the tsf value in
> set_tsf() be ?
> 11.1.4 (IEEE802.11-2007) says that the TSF has to be reset to zero on
> joining
> an IBSS network. We do that correctly.

In the praxis setting the TSF should not a problem as log the value is =
not higher then the original TSF from the other node. As long the clock=
s are working correct and the other node is not moved with nearly light=
-speed this shouldn't happen. ;)

> To calculate the next TBTT, we
> can't use the
> HW TSF, since it has just been reset. And the Beacon's timestamp + in=
tval
> + FUDGE
> is what we do in ath9k to get the TBTT for this peer, which I think i=
s
> correct.
> A sniffer shows the beacon generation being evenly distributed.

I think the TSF timer keep this value more up-to-date than a static var=
iable in RAM, so that e.g. the speed of the CPU has a lower effect on t=
he de-sync of this value.

Regards
Alina

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