wifi bit rate

[JD]

On 05/22/2012 02:56 PM, John Horne wrote:
> On Mon, 2012-05-21 at 17:19 -0700, JD wrote:
>> When I take my laptop to starbucks or McDonalds hot spot,
>> even when sitting outside, bitrate never is below 54mbps,
>> sometime is as high as 72mb/s
>>
> Hi,
>
> Reading through your messages, you have now said two things:
>
> 1) You used an RTL card and got the same problem;
> 2) Using the laptop elsewhere (starbucks) and it works fine.
>
> To me both of those tend to indicate that the WLAN card is okay, but
> perhaps your router (or at least something else) is causing a problem.
> The RTL card would have used a different driver than the Atheros.
Of course. The external rtl usb wifi adapter uses the
rtl8187 driver. So, I really doubt the linux driver is
behind this fixation of bit rate. All I am saying is that
I did not have this problem when I was on F14.
Perhaps something above the low lever driver is at
work here, either wext driver or wpa_supplicant
application. I found no settings on the router which
would set the bitrate per wifi client. The other 3
clients are all at 54 Mb/s.

>
> You also said that the card worked fine with F14. Although the ath9k
> driver will most likely have changed between F14 and F16, that wouldn't
> explain why it works fine at starbucks or why the RTL had the same
> problem.
Right.
>
> I would say take a look at the router to see if anything unusual is
> happening there.
>
> I have heard before that sometimes dropping the router/card to 802.11b
> or g can resolve odd problems with 802.11n cards. (Something like
> 'iwconfig wlan0 rate 54M') Obviously the speed will not be the best, but
> possibly better than 18Mb/s :-)
>
> Finally, if the driver really looks like a possibility, then you could
> run 'modinfo ath9k' to see what options the driver takes. It may have a
> debug option to cause further messages to be written to dmesg. Actually,
> checking dmesg may be a good step anyway (something like 'dmesg | grep
> ath').
>
> (FYI, I have an Atheros USB card which uses the carl9170 driver. The
> card is 802.11bgn, but my router is only 'b' or 'g'. I get a fairly
> consistent maximum 54Mb/s :-) )
I will look to see if the ath9k and the rtl8187 drivers have
debug options that can be turned on. If they do, then I
will have to recompile my kernel.