fast & selective & active scanning
Thu Feb 10 12:12:30 PST 2005
Hello people, i have a Senao 2511 Plus card (firmware 1.3.6) and i'm using
HostAP drivers to implement experimental algorithms in scanning/handoff
I measured that an association to an access point, from the
HFA384X_RID_JOINREQUEST command, to notification handled by
hostap_info_process(), is about 14 ms long.... this is the good thing.
The bad one is that to do handoff, i have to scan for other access points,
then i measured that to scan a single channel with a fixed essid using
HFA384X_RID_HOSTSCAN command, card needs further on 80 ms!! this is too much
considering that channels are 11 and that i have to periodically (1-2
seconds) scan all of them.
Analyzing kismet and ethereal results, i see that probe request/response
happen in less than 1 ms. when card is scanning, it sends a broadcast probe
request and evidently waits for responses with a fixed timeout. i would be
able to modify dinamically this timeout or to interrupt scanning a channel,
i.e. when a probe request is received, but i fear that this code can be
handled only by the firmware...
is it possible to forge probe requests in a channel, and handle responses,
without loosing actual ap association in another channel?
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