DD-WRT extra wireless channels

After installing DD-WRT on my WRT54G i noticed that it unlocked 3 extra wireless channels, I now have channels 1 - 14 instead of 1 - 11. Are 12, 13, and 14 even FCC legal? Do wireless adaptor cards even support these channels?

i think if im not mistaken thoes are channels that are activated in europe... i dunno about compatibility with wireless cards bought here in the USA... give it a try, mabey some google searchin.

This is what I found out.


I had no luck on finding out what the FCC has the small bit of the spectrum containing the last three channels allocated for. I did find out that operating in this area in unlicensed areas can result in a $5k fine.

CFR 47, Part 2 covers frequency allocations. Here's an excerpt of the 2400-2500MHz region:

Federal
2400-2417: (nothing listed)
2417-2450: Radiolocation
2450-2483.5: (nothing listed)
2483.5-2500: MOBILE-SATELLITE (space-to-Earth), RADIODETERMINATION-SATELLITE (space-to-Earth)

Non-Federal
2400-2417: AMATEUR
2417-2450: Amateur
2450-2483.5: FIXED, MOBILE, Radiolocation
2483.5-2495: MOBILE-SATELLITE (space-to-Earth), RADIODETERMINATION-SATELLITE (space-to-Earth)
2495-2500: FIXED, MOBILE (except aeronautical mobile), MOBILE-SATELLITE (space-to-Earth), RADIODETERMINATION-SATELLITE (space-to-Earth)

As you can see, the spectrum there isn't exactly "reserved" for WiFi Where WiFi gets to play is determined by Part 15, which allows for unlicensed operation in the 2400-2483.5MHz band (among numerous others). Unlicensed operation under Part 15 comes with lots of "gotchas" that limit what you can do (for example, it's responsible for the 1 watt transmission limit). Part 18, which deals with ISM (Industrial, Scientific, and Medical) equipment has been mentioned by a number of websites as possibly also applying to WiFi operation, though I haven't read any of it to determine how.

Each WiFi channel's center is seperated by 5MHz, but are 22MHz wide. The highest frequency WiFi could operate at should be 2472.5MHz, corresponding to Channel 13. That explains why Channel 14 isn't allowed, and I imagine that some further restriction in Part 18, a different definition of channel bandwidth in Part 15, or just a "safety margin" when designing the protocol could explain the lack of Channel 12 and 13 in the US.

JigPu

There also used to be something saying that you can operate any ground based transmitter on any frequency so long as its not more than 100mw and is not interfering with anyone. I dont know if they revised it. I talk with alot of amateur radio hobbiests and as far as they know it hasnt been lifted,.. yet. My WIFI is at 28mw right now. Enough to cover my house, and thats about it. past my driveway you cant get the signal anymore.

intresting... i think ill stick with my channel 9... no one ever uses it and theres ppl only using ch 1 and 6 where i live so i chose channel 9, got way better quality and strength by doing so

only 1-11 can be used in the US with 12-13 beings usable in europe and 14 in japan IIRC.