xonito
Posts: 13
Joined: Sat Feb 16, 2013 4:02 pm

[SOLVED] Wireless not recognize channels 12 and 13

Tue Mar 12, 2013 11:22 pm

Hello:

Someone is able to use a wireless adapter on channel 13? I'm from Spain and here is allowed to use channel 12 and 13, and I have changed the region of CRDA to "ES" and I can not use my wireless adapter channel 13.

I think the problem is in the kernel, but not how to solve the problem.

Sorry my english :(

P.D. Using the distribution Raspbian
Last edited by xonito on Wed Mar 13, 2013 1:51 am, edited 1 time in total.

anto
Posts: 26
Joined: Tue Jan 01, 2013 5:20 pm
Location: Vienna, Austria

Re: Wireless not recognize channels 12 and 13

Wed Mar 13, 2013 12:10 am

Are you sure that your WLAN adapter is able to use channel above 11? Maybe you have the one that should only be used in North America.

Could you please let us know the detail of your WLAN adapter? Made, model, etc?

xonito
Posts: 13
Joined: Sat Feb 16, 2013 4:02 pm

Re: Wireless not recognize channels 12 and 13

Wed Mar 13, 2013 12:24 am

My adapter is a TP-Link TL-WN722N

I've been using it on other computers with Windows 7, Ubuntu and Debian and have always been recognized channel 13, but there is no way Raspbian: (

http://www.amazon.com/Tp-Link-Tl-Wn722N ... 78-0842936

anto
Posts: 26
Joined: Tue Jan 01, 2013 5:20 pm
Location: Vienna, Austria

Re: Wireless not recognize channels 12 and 13

Wed Mar 13, 2013 1:05 am

If that works on other OS then that is definitely driver issues.
Briefly reading the experiences of other people using the same WLAN adapter on Linux, it looks that you need the right Atheros driver. I am quite sure this is not specify problem of Raspbian. Did you try to search the internet for the solutions?
I found this blog, explaining about installing the driver for TP-LINK TL-WN722N in Linux. It looks like it is a good blog for you, as it is in Spanish! So good luck. :)

xonito
Posts: 13
Joined: Sat Feb 16, 2013 4:02 pm

Re: Wireless not recognize channels 12 and 13

Wed Mar 13, 2013 1:50 am

I've solved installing firmware-linux-nonfree

Code: Select all

apt-get install firmware-linux-nonfree
then I installed the package CRDA

Code: Select all

apt-get install crda
Then change the adapter region of "ES" of Spain

Code: Select all

iw reg set ES
Raspberry and finally restart to make the changes

Code: Select all

shutdown -r now
Once started again Raspberry, made ​​a

Code: Select all

iw list |grep Frequencies -A 13
And this come confirming that all channels are enabled 1 to 13
Frequencies:
* 2412 MHz [1] (20.0 dBm)
* 2417 MHz [2] (20.0 dBm)
* 2422 MHz [3] (20.0 dBm)
* 2427 MHz [4] (20.0 dBm)
* 2432 MHz [5] (20.0 dBm)
* 2437 MHz [6] (20.0 dBm)
* 2442 MHz [7] (20.0 dBm)
* 2447 MHz [8] (20.0 dBm)
* 2452 MHz [9] (20.0 dBm)
* 2457 MHz [10] (20.0 dBm)
* 2462 MHz [11] (20.0 dBm)
* 2467 MHz [12] (20.0 dBm)
* 2472 MHz [13] (20.0 dBm)

stevech
Posts: 144
Joined: Sun Jul 15, 2012 11:53 pm

Re: [SOLVED] Wireless not recognize channels 12 and 13

Wed Mar 13, 2013 4:37 am

Don't use those two high channels in North America. Other radio services use those frequencies.

xonito
Posts: 13
Joined: Sat Feb 16, 2013 4:02 pm

Re: [SOLVED] Wireless not recognize channels 12 and 13

Wed Mar 13, 2013 10:16 am

I'm from Spain, here are allowed channels 12 and 13

pjc123
Posts: 921
Joined: Thu Mar 29, 2012 3:37 pm
Contact: Website

Re: [SOLVED] Wireless not recognize channels 12 and 13

Wed Mar 13, 2013 1:06 pm

stevech wrote:Don't use those two high channels in North America. Other radio services use those frequencies.
I was wondering why my smartphone wifi app was recommending that I switch to the higher uncongested frequencies here in the US, which for the reasons you just explained, do not even exist on my router. Router only goes up to channel 11 while the app goes up to channel 14.
My Raspberry Pi Project Page:

https://www.flaminghellmet.com/launch/

xonito
Posts: 13
Joined: Sat Feb 16, 2013 4:02 pm

Re: [SOLVED] Wireless not recognize channels 12 and 13

Wed Mar 13, 2013 1:27 pm

If your router allows linux based firmwares, type OpenWrt, DD-WRT, Tomato ... You can change the region of your country in order to use higher channels

I use channel 13 because other channels are quite congested and so I have no interference with other wireless networks

pjc123
Posts: 921
Joined: Thu Mar 29, 2012 3:37 pm
Contact: Website

Re: [SOLVED] Wireless not recognize channels 12 and 13

Wed Mar 13, 2013 8:38 pm

xonito wrote:If your router allows linux based firmwares, type OpenWrt, DD-WRT, Tomato ... You can change the region of your country in order to use higher channels

I use channel 13 because other channels are quite congested and so I have no interference with other wireless networks
I am running Shibby Tomato, but I have no desire to break FCC rules. Creative workaround though.
My Raspberry Pi Project Page:

https://www.flaminghellmet.com/launch/

pjc123
Posts: 921
Joined: Thu Mar 29, 2012 3:37 pm
Contact: Website

Re: [SOLVED] Wireless not recognize channels 12 and 13

Thu Mar 14, 2013 1:09 pm

Curiosity got the better of me. What I discovered as far as Wifi channels 12, 13 and 14 in the US, according to the FCC, is that there are restrictions so they do not interfere with other higher assigned frequencies. Channel 14 is not permitted at all because it clearly interferes with another assigned frequency band, and channel 12 and 13 are permitted as long as special field strength limits are adhered to, taking into consideration both power level and antenna db gain. Router manufacturers just use Channels 1 -11 to avoid all of this.

Here are the assigned frequencies at and near Wifi (2.4 GHz).

2400 - 2450 MHz (ISM Equipment, Amateur Radio)

2450 - 2483.5 MHz (ISM Equipment, TV Auxiliary Broadcasting, Private Land Mobile, Fixed Microwave)

2483.5 - 2500 MHz (ISM Equipment, Satellite Communications, Wireless Communications)



Wifi Channels and Frequencies:

Channel 1: 2.412 MHz
Channel 2: 2.417 MHz
Channel 3: 2.422 MHz
Channel 4: 2.427 MHz
Channel 5: 2.432 MHz
Channel 6: 2.437 MHz
Channel 7: 2.442 MHz
Channel 8: 2.447 MHz
Channel 9: 2.452 MHz
Channel 10: 2.457 MHz
Channel 11: 2.462 MHz
Channel 12: 2.467 MHz
Channel 13: 2.472 MHz
Channel 14: 2.484 MHz
My Raspberry Pi Project Page:

https://www.flaminghellmet.com/launch/

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