<p style="MARGIN: 0in 0in 0pt"><span style="FONT-FAMILY: Arial">hi,<br><br>I am working in a R&D project, time driven switiching network, goal is to forward IP packet with respect to time (UTC) along with destination IP address [1].
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<p style="MARGIN: 0in 0in 0pt"><span style="FONT-FAMILY: Arial">Its wireless extension, I was interested, objective is to control over sending beacon frame from AP.</span></p>
<p style="MARGIN: 0in 0in 0pt"><span style="FONT-FAMILY: Arial">I know, this work is much more hardware depended and lower MAC layer of 802.11, time synchronization functionality (TSF). Without much knowledge, I started work with madwifi and I implemented (customized) the idea but because of close code of HAL (hardware abstraction layer) from atheros, I could not do following stuff.
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<p style="MARGIN: 0in 0in 0pt"><span style="FONT-FAMILY: Arial">Idea is simple: beacon frame is sending according to TSF chipset timer, host linux kernel is getting another timer, through time-driven network, <span> </span>
there may be some drift between two timer. <span> </span>if the drift cross some threshold (say 1 msec), adjust beacon sending time. </span></p>
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<p style="MARGIN: 0in 0in 0pt"><span style="FONT-FAMILY: Arial">In my implementation, I was able to restart beacon sending but I got a problem, Probably because of close routine :</span></p>
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<p style="MARGIN: 0in 0in 0pt"><span style="FONT-FAMILY: Arial"> 1.<span> </span>it was reseting TSF timer, means it starts with zero again.</span></p>
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<li style="MARGIN: 0in 0in 0pt"><span style="FONT-FAMILY: Arial">to initialize hardware beacon state, I had to give beacon interval in TU unit, but in my research, I needed to send beacon millisecond (ms) unit interval <span>
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<p style="MARGIN: 0in 0in 0pt 0.25in"><span style="FONT-FAMILY: Arial">( 1 TU = 1.024 ms<span> </span>~ 100 ms = 97.65625 TU ) <span> </span><span> </span></span></p>
<p style="MARGIN: 0in 0in 0pt 0.25in"><span style="FONT-FAMILY: Arial">I cannot put non-integer value as beacon interval</span></p>
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<p style="MARGIN: 0in 0in 0pt 0.25in"><span style="FONT-FAMILY: Arial">I want to try with HostAP driver and ultimately port to some embedded box</span></p>
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<p style="MARGIN: 0in 0in 0pt 0.25in"><span style="FONT-FAMILY: Arial">My question, is it possible to overcome above two problems without having any code (or microcontroller) from vendor?</span></p>
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<p style="MARGIN: 0in 0in 0pt 0.25in"><span style="FONT-FAMILY: Arial"> -</span></p>
<p style="MARGIN: 0in 0in 0pt 0.25in"><span style="FONT-FAMILY: Arial">/dipankar</span></p>
<p style="MARGIN: 0in 0in 0pt 0.25in"><span style="FONT-FAMILY: Arial"></span> </p>
<p style="MARGIN: 0in 0in 0pt 0.25in"><span style="FONT-FAMILY: Arial">[1] <a onclick="return top.js.OpenExtLink(window,event,this)" href="http://ip-flow.dit.unitn.it/" target="_blank">http://ip-flow.dit.unitn.it/</a>
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