compex WLM200NX (ath9k) dual band issue

Walter Robert Ditzler ditwal001
Tue Nov 20 17:23:27 PST 2012


chris, that happens when brain's turned off - of course only one band at the
same time - related to the available mac address!

sorry for my stupid question but i didnt see it at the end - i got confused
by some weired infos found on the net :(

thanks a lot fort he hint!


-----Original Message-----
From: Christian Lamparter [mailto:chunkeey at] 
Sent: Mittwoch, 21. November 2012 01:22
To: Walter Robert Ditzler
Cc: hostap at
Subject: Re: compex WLM200NX (ath9k) dual band issue

Hello Walter,

On Wednesday, November 21, 2012 12:22:20 AM Walter Robert Ditzler wrote:
> sorry form y weak description. i saw some examples running a hostapd 
> setup with one card simultaniously on both freq (2.4 and 5).
Ah, can you tell me where you saw this example? 

> in my case i just doesnt work. from your comment bellow, is it true 
> that this is not possible? if it is possible can you help me with a 
> hint how to proceed?
No, unfortunately it's not possible with any "run-off-the-mill" hardware I
known. In your case, the chip on the WLM200NX seems to be a AR9220, which is
part of the AR9280 series. the public specs can be found at:

Of course the textblob there isn't particular helpful (in fact it's
confusing), but there's a "key" sentence in there:

"Single-chip, 802.11n compliant wireless LAN client solution with integrated
MAC, baseband and dual 2.4/5 GHz radios"

What this means is: The solution has dual 2.4/5GHz radios, it only has one
media access controller (MAC) to drive either one of them.
[The MAC deals with CSMA/CA, hw de-/encryption, bits of aggregation, ... 
so you can't live without one]. And because there's only one MAC, the other
radio is simply switched off and can't be used.  [Is this useful? Or do you
need more technical details?]

Note: dual-band routers usually have two independent wifi chips!
So, if you have an empty minipci-slot you could add another AR9220 (or go
for a cheaper 2.4GHz-only AR9223). This way you can make your own
"simultaneous dual-band" platform.
If this is not an option, then you could add an additional ath9k_htc
<> usb adapter to your
system and run the 5GHz AP from the WLM200NX. [your call]


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