Phoenix Network Forums

I dont know about you but I would be very interested in building my own cell phone. It seems now that someone has taken this idea to heart and created a homebrew cell phone club much akin to the Chaos Computer Club.

http://telefono.revejo.org/article/10/s ... phone-club

http://news.com.com/Build-it-yourself+c ... 53682.html

http://www.seattlewireless.net/~casey/i ... i/2005/05/

so here is my question. What applications can you see comming out of the woodwork as this becomes a bigger and more viable movement?

i predict :
using your cellphone as a garage door opener.
using your phone as a TV-B-Gone

FYI this is illegal. Building an electronic device that transmits a radio signal (an "intentional radiator") without a license violates federal law and FCC regulations (in Europe there are similar CE regulations).

Maximum penalties are $400,000 fine, plus $25,000/day fine, plus forfeiture of all equipment, plus (if you sold any) forfeiture of double your revenue. Although, typically people are fined ~$10,000.

In Europe you can face six months in jail.

that is true...but at the same time not. What the fcc is talking about in that rule is radio signals ( ie pirate radio, radio telescopes, et al.) . If you so decide to build a cellphone and connect it to a network that has the fcc's approval you are not in violation of the law =)

The only way you have permission to operate an intentional radiator without an FCC licesnes is in accordance with 47 CFR §15. (so called part 15 devices). There are restrictions on the frequencies that can be used in these devices. For reference the GSM bands are as follows:

Code: Select all

    *  850 MHz   (824.2 - 848.8 MHz Tx;  869.2 - 893.8 MHz Rx)
    *  900 MHz   (880-2 - 914.8 MHz Tx;  925.2 - 959.8 MHz Rx)
    *  1800 MHz  (1710.2 - 1784.8 MHz Tx; 1805.2 - 1879.8 MHz Rx)
    *  1900 MHz  (1850.2 - 1909.8 MHz Tx; 1930.2 - 1989.8 MHz Rx)


Now from 47 CFR §15.243

Operation in the band 890–940 MHz.

(a) Operation under the provisions of this section is restricted to devices that use radio frequency energy to measure the characteristics of a material. Devices operated pursuant to the provisions of this section shall not be used for voice communications or the transmission of any other type of message.

The, 1800MHz band is hard to use also becuase § 15.205 prohibits any operation in the 1718.8-1722.2MHz range. But, you are right, I cannot find anything prohibiting you from building something to work in the 850 or 1900 MHz bands.

Note however that that does not mean a reg. doesn't exist. I just can't find it.