[Madwifi-devel] Beacon Timestamps

[Dattatraya <dgo...@gm...>]

Hi...

I was trying to figure out the time synchronisation mechanism using beacons
and the standard seems to indicate that one needs to maintain a time
synchronisation of about 4 micro-secs with respect to the beacon.

I thought that such kind of accuracy was achievable only at the hardware
layer however while I was looking through the madwifi code and it seems to
me that this is being done by the driver in net80211/ieee80211_input.

I have a couple of questions and would be very obliged if someone could
point me in the rigth direction / point out that my assumptions may are
wrong...

1. How is one able to chieve such fine time synchronisation at the driver
level?

2. If I insert printk statements before and after the time stamp is being
copied from a received beacon, will I be able to work out for a pair of node
by how much the clocks are going out of sync?

3.  If I can repeat this process over more than one hop is it technically
possible to  synchrnise a  node  two hops down with a node  upstream by
minor changes to the madwif code?

Thanks and Regards

-- 
Dattatraya

-------------------------------------------------
"When we long for life without difficulties, remind us that oaks grow strong
in contrary winds and diamonds are made under pressure"
-- -- -- Peter Marshall