Hi,
On Wed, 17 Mar 2010, Bruno Randolf wrote:
> hey!
>
> Here is a preliminary Ambient Noise Imunity (ANI) implementation for ath5k. it
> works only for newer chips (MAC > 0x59) and i still have some little things to
> fix, but it works well for my test cases here, giving me around 24Mbps
> (compared to 15Mbps in my worst case without ANI) on my 5414 chipset (i only
> tested it on this chipset). I will continue to work on it, but i send this for
> other people to test and review.
>
Fantastic to see this.. Good job.
Some issues come to mind:
> + else if (strncmp(buf, "ofdm-off", 8) == 0) {
> + ath5k_ani_set_cck_weak_signal_detection(sc->ah, 0);
> + }
> + else if (strncmp(buf, "ofdm-on", 7) == 0) {
> + ath5k_ani_set_cck_weak_signal_detection(sc->ah, 1);
> + }
> + else if (strncmp(buf, "cck-off", 7) == 0) {
> + ath5k_ani_set_cck_weak_signal_detection(sc->ah, 0);
> + }
> + else if (strncmp(buf, "cck-on", 6) == 0) {
> + ath5k_ani_set_cck_weak_signal_detection(sc->ah, 1);
When selecting ofdm on or off, the code should call ofdm on/off - surely?
For IBSS mode, things are quite different to access point/station mode.
In IBSS mode, a node will attempt to communicate with any other node in
the network, at any time.
You see, a new node could be turned on, or brought into vague proximity of
the network at any time. Consequently, the sensitivity level required by
the current nodes in the network is unknown.
it is conceivable in IBSS that one node is carrying out two simultaneous
"conversations", where one node is close by, and one node is far away. In
this case, what should the sensitivity be adjusted to?
Something like::
A---B-------------------C
A is close to B, B is far from C. What sensitivity level should B use?
The sensitivity adjustment code does not know who is being communicated
with.
the sensitivity adjustment code could use the data in the minstrel table.
Suppose all nodes are close by. The minstrel table says all links are
good, so the driver winds the sensitivity down. But this would mean that
when a far away node is turned on communication is not possible. However,
that far away node should be able to communicate - the slot times etc are
all long enough.
With madwifi, outdoors, 2 km links, I found the best thing to do was wind
the sensitity up to near maximum, and leave it there, fixed. (ani
disabled, sensitivity would up by using the relevant code from the open
sourced hal ((thanks Atheros))).
Derek.
--
Derek Smithies Ph.D.
IndraNet Technologies Ltd.
ph +64 3 365 6485
Web: http://www.indranet-technologies.com/
"How did you make it work??"
"Oh, the usual, get everything right".
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