Problems with RaLink rt61pci/rt2561 wifi card

[Jakob Pedersen]

Hi Adrian,

Thank you for the tips for diagnosing my WiFi issue. It seems to be the
gain settings on the wifi card somehow (I am in not much of a technical
person, but at least that's what it seems to me). For PC-BSD the signal
strength is measured to -54 dB just next to the router and when stepping
away like 5 - 6 metres the signal is lost at -95 dB (Same level as noise dB
level). The decrease in not sudden but drops gradually when distance to
router is being increased. I am dual booting Arch linux on the same laptop,
where WiFi works fine and it measures - 20 dBm next to the router and - 70
dBm where PC-BSD looses connection. Not really sure, what to do from here
though..

But thanks, anyway!

Jakob
On Wed, Feb 15, 2012 at 8:09 AM, Adrian Chadd <adrian at freebsd.org> wrote:

> Hi,
>
> It sounds like it could be:
>
> * low TX power from your device;
> * Really bad RX gain settings somehow;
> * other fruity radio related stuff.
>
> The trouble is going to be diagnosing it. What I do in these instances
> is use a known-good setup (i have a bunch of laptops with AR9280's in
> them for this reason) to use in monitor mode - I can then get a rough
> estimate of TX power by just sniffing the frames your device is
> sending.
>
> That'd hopefully identify whether it's a TX or an RX problem.
>
> If the device works in monitor mode, you could try that:
>
> tcpdump -ni wlan0 -y IEEE802_11_RADIO
>
> Connect, then walk away from the AP. See if the RX RSSI fields in the
> tcpdump drop suddenly. If you get a few metres away and you're still
> receiving things strong, it may be a TX issue. If you suddenly stop
> hearing anything, it's likely an RX issue.
>
> Good luck!
>
>
> Adrian
>