Switching band of a dual-band WiFi device

Switching band of a dual-band WiFi device

[Christian Gagneraud]

Hi there,

I am using a TP-Link TL-WDN3200 on a ubuntu 13.04 (kernel 
3.8.0-27-generic), and I have install relevant modules with 
backports-3.11-rc3-1.

I would like to switch my WiFi stick to 5GHz, I tried iwconfig wlan0 
freq 5G, but I get ENOTSUPP.
Is the freq settings suppose to handle this 2.4 vs 5GHz band or is it 
only for selecting channel frequency within a given band?

Does linux-wireless provides a way for selecting 2.4 or 5GHz band?

"iw phy phy11 info" tells me that in band 2, all the frequencies are 
disabled except:
                         * 5745 MHz [149] (30.0 dBm)
                         * 5755 MHz [151] (30.0 dBm)
                         * 5765 MHz [153] (30.0 dBm)
                         * 5775 MHz [155] (30.0 dBm)
                         * 5785 MHz [157] (30.0 dBm)
                         * 5795 MHz [159] (30.0 dBm)
                         * 5805 MHz [161] (30.0 dBm)
                         * 5825 MHz [165] (30.0 dBm)

As well, my understanding of WiFi might be a bit limited but, does a 
dual-band WiFi device provides 2.4 and 5GHz services at the same time or 
do I need to select one or the other myself? Or maybe I can just 
enable/disable them manually (and separately)?

Hope someone can shed some light at this.

Regards,
Chris

Re: Switching band of a dual-band WiFi device

[Christian Gagneraud]

On 15/08/13 17:30, Siyu Qiu wrote:
> hi, do you mean that you take the wireless card from tplink and embed it
> into your pc ? Does it work ? Coz i want to put qca 9889 into pc but the
> info about network controller is :!!! unknown type 7f

Hi Siyu Qio,

I'm not sure to understand your question, but this is what I did
- went to the shop to buy this USB stick
- plugged it in a USB slot of my PC

And now I'm trying to understand if I can switch/enable/disable these 2 
bands, and more importantly, do I really need to?
Right now, my feeling is that "it just works out of the box", I 
shouldn't try to do this kind of things. I just try to understand this 
dual-band thing.

Chris

PS: Can you reply on the mailing list instead of sending private email 
please?


>
> On Aug 14, 2013 10:12 PM, "Christian Gagneraud" <chgans@gna.org
> <mailto:chgans@gna.org>> wrote:
>
>     Hi there,
>
>     I am using a TP-Link TL-WDN3200 on a ubuntu 13.04 (kernel
>     3.8.0-27-generic), and I have install relevant modules with
>     backports-3.11-rc3-1.
>
>     I would like to switch my WiFi stick to 5GHz, I tried iwconfig wlan0
>     freq 5G, but I get ENOTSUPP.
>     Is the freq settings suppose to handle this 2.4 vs 5GHz band or is
>     it only for selecting channel frequency within a given band?
>
>     Does linux-wireless provides a way for selecting 2.4 or 5GHz band?
>
>     "iw phy phy11 info" tells me that in band 2, all the frequencies are
>     disabled except:
>                              * 5745 MHz [149] (30.0 dBm)
>                              * 5755 MHz [151] (30.0 dBm)
>                              * 5765 MHz [153] (30.0 dBm)
>                              * 5775 MHz [155] (30.0 dBm)
>                              * 5785 MHz [157] (30.0 dBm)
>                              * 5795 MHz [159] (30.0 dBm)
>                              * 5805 MHz [161] (30.0 dBm)
>                              * 5825 MHz [165] (30.0 dBm)
>
>     As well, my understanding of WiFi might be a bit limited but, does a
>     dual-band WiFi device provides 2.4 and 5GHz services at the same
>     time or do I need to select one or the other myself? Or maybe I can
>     just enable/disable them manually (and separately)?
>
>     Hope someone can shed some light at this.
>
>     Regards,
>     Chris
>     --
>     To unsubscribe from this list: send the line "unsubscribe
>     linux-wireless" in
>     the body of a message to majordomo@vger.kernel.org
>     <mailto:majordomo@vger.kernel.org>
>     More majordomo info at http://vger.kernel.org/__majordomo-info.html
>     <http://vger.kernel.org/majordomo-info.html>
>

Re: Switching band of a dual-band WiFi device

[Simon Farnsworth]

[-- Attachment #1: Type: text/plain, Size: 2136 bytes --]

On Thursday 15 August 2013 17:11:59 Christian Gagneraud wrote:
> Hi there,
> 
> I am using a TP-Link TL-WDN3200 on a ubuntu 13.04 (kernel 
> 3.8.0-27-generic), and I have install relevant modules with 
> backports-3.11-rc3-1.
> 
> I would like to switch my WiFi stick to 5GHz, I tried iwconfig wlan0 
> freq 5G, but I get ENOTSUPP.
> Is the freq settings suppose to handle this 2.4 vs 5GHz band or is it 
> only for selecting channel frequency within a given band?
> 
> Does linux-wireless provides a way for selecting 2.4 or 5GHz band?

Linux should automatically select the right frequency band, depending on
the frequencies in use by the device you're trying to communicate with.
Connect to an AP in the 5GHz band, and Linux should just use 5GHz
automatically.
> 
> "iw phy phy11 info" tells me that in band 2, all the frequencies are 
> disabled except:
>                          * 5745 MHz [149] (30.0 dBm)
>                          * 5755 MHz [151] (30.0 dBm)
>                          * 5765 MHz [153] (30.0 dBm)
>                          * 5775 MHz [155] (30.0 dBm)
>                          * 5785 MHz [157] (30.0 dBm)
>                          * 5795 MHz [159] (30.0 dBm)
>                          * 5805 MHz [161] (30.0 dBm)
>                          * 5825 MHz [165] (30.0 dBm)
> 
That's showing you that, with Linux's understanding of the RF regulations in
your area, it can only transmit on certain frequencies.

> As well, my understanding of WiFi might be a bit limited but, does a 
> dual-band WiFi device provides 2.4 and 5GHz services at the same time or 
> do I need to select one or the other myself? Or maybe I can just 
> enable/disable them manually (and separately)?
> 
A dual-band WiFi device can only transmit and receive on one channel at a
time. The advantage of dual-band is that it can transmit and receive on either
the 5GHz band (which is less crowded), or the 2.4GHz band (which is more
commonly used). There's no need to select the band manually - it will just
use 5GHz when the other device (e.g. the AP) is using 5GHz.
-- 
Simon Farnsworth
Software Engineer
ONELAN Ltd
http://www.onelan.com

[-- Attachment #2: This is a digitally signed message part. --]
[-- Type: application/pgp-signature, Size: 490 bytes --]

Re: Switching band of a dual-band WiFi device

[Christian Gagneraud]

On 15/08/13 21:03, Simon Farnsworth wrote:
> On Thursday 15 August 2013 17:11:59 Christian Gagneraud wrote:
>> Hi there,
>>
>> I am using a TP-Link TL-WDN3200 on a ubuntu 13.04 (kernel
>> 3.8.0-27-generic), and I have install relevant modules with
>> backports-3.11-rc3-1.
>>
>> I would like to switch my WiFi stick to 5GHz, I tried iwconfig wlan0
>> freq 5G, but I get ENOTSUPP.
>> Is the freq settings suppose to handle this 2.4 vs 5GHz band or is it
>> only for selecting channel frequency within a given band?
>>
>> Does linux-wireless provides a way for selecting 2.4 or 5GHz band?
>
> Linux should automatically select the right frequency band, depending on
> the frequencies in use by the device you're trying to communicate with.
> Connect to an AP in the 5GHz band, and Linux should just use 5GHz
> automatically.
>>
>> "iw phy phy11 info" tells me that in band 2, all the frequencies are
>> disabled except:
>>                           * 5745 MHz [149] (30.0 dBm)
>>                           * 5755 MHz [151] (30.0 dBm)
>>                           * 5765 MHz [153] (30.0 dBm)
>>                           * 5775 MHz [155] (30.0 dBm)
>>                           * 5785 MHz [157] (30.0 dBm)
>>                           * 5795 MHz [159] (30.0 dBm)
>>                           * 5805 MHz [161] (30.0 dBm)
>>                           * 5825 MHz [165] (30.0 dBm)
>>
> That's showing you that, with Linux's understanding of the RF regulations in
> your area, it can only transmit on certain frequencies.

OK, that's the CRDA thing, I understand now! ;)

>
>> As well, my understanding of WiFi might be a bit limited but, does a
>> dual-band WiFi device provides 2.4 and 5GHz services at the same time or
>> do I need to select one or the other myself? Or maybe I can just
>> enable/disable them manually (and separately)?
>>
> A dual-band WiFi device can only transmit and receive on one channel at a
> time. The advantage of dual-band is that it can transmit and receive on either
> the 5GHz band (which is less crowded), or the 2.4GHz band (which is more
> commonly used). There's no need to select the band manually - it will just
> use 5GHz when the other device (e.g. the AP) is using 5GHz.
>

Thanks for your answers Simon, everything is working now.
I had to change the regulatory domain of the USB stick to NZ as it comes 
with CN (country of origin) and NZ/CN don't really overlap in the 5GHz band.

Regards,
Chris