Hello there,

I'm searching about why only 13 channels available on 2.4Ghz and why we could switch to 5Ghz.

While searching, I found 2.4Ghz devices can create more channels than 13 channels. It is not something compareable with 5ghz but it's still very good while we have bunch of devices still can only operate at 2.4Ghz.

Like their name, these devices can only opreate at 2.4Ghz, between 2400Mhz and 2500Mhz. Every channel has 22Mhz bandwidth. We can choose anything in 2400 and 2500.

There are a standart about where are those channels are, it's shown below:

As you noticed, there are 13 channels, which sepearated with 5Mhz gap between them to block interference. (Igrone channel 14, it's only available to 802.11b)

But why there are no 2477, 2482 and 2487 a.k.a. 14, 15 and 16? Let's discuss about this. And if it turns good, include support for these channels on OpenWRT.

afaik mostly the problem is law.

plus, on openwrt there are problems even to use channel 13 in EU without an HACK, so you will never see "strange" channels supported imho.

you can google about dd-wrt superchannel, if you really think it's useful.

(Last edited by nebbia88 on 25 Dec 2013, 16:05)

Which EU country is this? Only US has a law about that, limits our devices to 2,400–2,483.5 MHz. Rest of the world allows this. Also even we are on US, I don't think we are going to jail for using these channels.

edit: Just saw your edit. Can we implement this function to openwrt? It's really useful.

Frequencies are regulated worldwide.

That is wrong. In Germany there is a plan ("Frequenznutzungsplan") from the BNetzA (similar to FCC).
You shouldn't violate these plans and you are disturbing other users (amateur radio ...) because you do not want to play by the rules.

Don't know about the US but there are some google results indicating possible jail time
http://www.moonblinkwifi.com/fcc_regula … g_8021.cfm

Having the possibility would be nice though, just for educational purposes Ubiquity firmwares can use much wider spectrum, when you specify country "compliance test" Everybody can use a cellular to trigger a bomb...

(Last edited by nozombian on 26 Dec 2013, 17:02)

Well let's say US + Germany. This does not change anything. Why we are moving to 5Ghz? Move amateur radios. I don't wanna waste money to switching all my devices to 5Ghz.

Uh uh. What's next? Jailing for speaking because we are using 20-20,000 Hz band without proper certification?

Agree.

The problem is, that "air" is for everybody and because frequencies are limited, some are paid (and very expensive), some are free, but in civilized world everything should have its regulations. 20Hz-20kHz spectrum is free for communication, but even that frequency you can't use it as you like,  imagine a drunk neighbour singing loud late in the night, when you want to sleep There are limits and that's how it should be

There's a big difference between having the possibility to use the frequency (even when it is forbidden in most states) and exploiting it Here in Czech Republic you can have a gun to defend yourself, but when you shoot a thief, you go for 10 years to jail. In USA, you just call cops ant they get rid of the body, however you end up in jail there when you bath naked with your wife and children by the sea. Life is not fair But that's a different topic.

(Last edited by nozombian on 28 Dec 2013, 00:03)

I agree about frequencies are limited in the air, but how many amateur radio users are there compared to people using wi-fi? Of course there are more users using wi-fi and because of that, they shoud be switch to different frequency. But, as you said, Life is not fair

Anyway, please concentrate about making this happen instead of talking regulations. We can copy channel locations (and some code if that's not violate our license terms) from DD-WRT. What about support on non-embedded systems? Can my laptop connect these "extra" channels?

Why not simply switch to a country that allows those extra channels?

and don't forget jow's reghack http://luci.subsignal.org/~jow/reghack/README.txt http://wiki.openwrt.org/doc/faq/faq.wir … .12.and.13
But that will only allow up to 13 iirc (14 is only available in Japan if you use 802.11b)

Also you could change the file https://dev.openwrt.org/browser/trunk/p … /regdb.txt
and don't forget to change CONFIG_ATH_USER_REGD=y in the .config ( Force Atheros drivers to respect the user's regdomain settings in makemenuconfig).

But then it would still be a pain to use channel 14.

(Last edited by FriedZombie on 29 Dec 2013, 01:30)

I already have 13 channels. The point is getting more than 13 channels, like DD-WRT superchannel.

edit: Like you said, Channel 14 is only supports 802.11b. Which is a standart I'm not going to use.