Hi all, Thanks all of you for a great discussion. I got a lot of useful inputs in a very short amount of time. So thanks so much for that.
Ashish On Mon, Jul 27, 2009 at 2:06 PM, Robert Sombrutzki < [email protected]> wrote: > Even if you don't want to change the channel per packet basis, it makes > sence > to use annotation instead of using syscalls. I implement a access point > using > click include parts of DFS (802.11h). There, the access point (ap) uses the > beacon to announce a channel switch. The ap has to switch the channel after > the beacon is send, where the time to switch is zero > (channelswicthannouncement). So you need exact channelswitch. > For the client, i use the same mechanism. Since the client has to send all > packet on the new channel after receiving the beacon from the ap (time to > switch=0), i use the annotation. A click-element analyse the received > beacon > and annotates the channel to the outgoing packets. If there is no outgoing > packet in the queue, the element generates a dummy-packet with the new > channel, which will be discard by the driver after setting the annotated > packet, to set the channel, which is also necessary to receive packets. > I think using annotations is a more accurate approach, then using syscalls. > > Best regards, > Robert > > On Montag, 27. Juli 2009, you wrote: > > Javier Sánchez wrote: > > > ok change the channel at ieee80211_hardstart() when the TX queues > > > initialize no problem. > > > > > > But u can change the channel per packet basis? i think this is not > > > possible, to change the channel the drivers needs to reset the chip > > > and restart the tx queues. It is not like change the rate , or the > > > retries.. which can be made per packet basis. > > > > > > But certainly i not tried or worked at it, may be i am wrong. > > > > This is the least of your problems, since tuning the analogue frontend > > of a wireless card can take looooong time, I would expect it somewhere > > in the order of of several milliseconds > > > > certainly something you don't want to do on a per-packet-basis.... > > > > but since the original question was: how to do that on reception of a > > dedicated control-packet: that can make perfect sense (given that these > > control packets don't happen too often...) > > > > _______________________________________________ > click mailing list > [email protected] > https://amsterdam.lcs.mit.edu/mailman/listinfo/click > _______________________________________________ click mailing list [email protected] https://amsterdam.lcs.mit.edu/mailman/listinfo/click
