Build Your Own Cell tower

BlakeCaldwell writes "If you're the type who dreads being dragged kicking and screaming into the use of a cell phone, Samsung sells their Long Range Cordless Phone. With an incredible (for landlines) 30-mile range, the set includes a caller ID-capable LCD and is able to communicate with the base-station, acting as an intercom."

Comments

legal issue in the US

[Flying Purple Wombat]

Most of these things are illegal in the US. They use frequecies assigned to other services, and power that far exceeds limits in FCC part 15.

I don't know about other places, but using that in the US risks huge fines ($10,000).

Don't do it in the U.S.

[Bruce Perens]

Here's what FCC did to someone who had one of these devices that operated in the ham bands.

Bruce

Re:Sweet!

[Subgenius]

Think twice folks, these devices are illegal to use in the US (lets not get into the 'rights of the airspace within a Farrady cage in a private club' stuff, ok?). Look for fines ranging from $7,500 to over $10k for 'wilfull and repeated violations' of FCC regulations if you fire one of these up (and your local hams or ANYONE ELSE reports you).

Most of these types radios use frequencies right in the midle of the the 2 meter band (140Mhz), allocated to gov't/amateur radio.

Just wait and see what happens when you fire up one of these and step all over coordinated 2m repeater....

Fake !

[MaxOliver]

This is not a Samsung model. In fact it is made by several Chinese factories as fakes of Samsung, SENAO, etc. They normally use HAM radio frequencies or comercial VHF/UHF. Due to the fact that they are only certified in China it is illegal to use in most countries.

Not a good idea if unlicensed...

[jim_deane]

If you operate one of these devices in the U.S., and it operates on ANY frequency used by the military, government, business, or amateur radio, you will be hunted down and taken out--by the FCC.

The price of the unit may be cheaper than cell phone bills, but add on that $10,000 fine and seizure of the equipment and it gets real expensive real quick.

And in case you think you're safe because it's in an amateur band, you should note that amateur radio operators practice RDF (Radio Direction Finding) or "Foxhunting" for fun. They will hunt you down, and the FCC accepts evidence from licensed operators in cases against violators.

Jim

FCC Fine Letters

[Subgenius]

Please read these before buying/using these phones...

http://www.fcc.gov/eb/Orders/2002/DA-02-453A1.html
http://www.fcc.gov/eb/Orders/2002/DA-02-2474A1.htm l

4. On July 27, 2001, agents from the Miami Office visited Lightning's retail store located at 231 E. Flagler Street, Unit #1, Miami, Florida. The agents saw several long-range, cordless telephones on display at the store, including a Super Phone CT-9000, a Prolink CT-6000CID, and an Optima OP8810. A salesperson
offered to sell one of the units to the agents. The long-range cordless telephones displayed at the store were capable of causing serious interference to aviation communications and were
not approved6 by the Commission for use in the United States.

Re:Sweet!

[VAXcat]

I concur...and there is no such thing as a frequency where no one will notice you...there is always an amateur radio op or scanner fan checking the spectrum for interesting signals.

Can be converted

[elgatozorbas]

No doubt this could be converted. HAM radio amateurs use something comparable which is called 'packet radio'. The most common rate (afaik) is 9k6, which is referred to as 'fast packet'. Probably you can do better (using your own modulation scheme), but not very much (assuming the link quality is comparable to normal telephone).

Something that I find surprising in some slashdotters is the fascination for wireless technology. Charming as it is, wireless is just another type of technology having its own benefits and hurdles. In general it is not the 'being wireless' part that is difficult: transmitters have existed for over 100 years.
I understand other people's fascination, but anyone can have his own transmitter, given that you can pass the HAM exam (if not you shouldn't be fooling around with wireless equipment anyway). Wireless links can be bought almost off-the-shelf.

IMHO the communication scheme itself is a lot more difficult. This can be understood easily by looking at the evolution of wireline modems: they started at 150 (or so) bps and worked their way up to 33kbps (higher rates use special tricks). All the time the medium remained the same, only progress was in the digital layers. For the same reason, I don't think it is fair to say 'wireless problem solved, halfway there'.
Just my 2ct...

Re:Sweet!

[deacon]

If you had bothered to read the linked articles you would have seen:

"Now for the long awaited question. I took the whole setup over to a friends place who is a ham radio operator. He immediately chastised me for importing such contraband into the country and continually tsked tsked me while he checked the frequency on the equipment and salivated over it all wishing he had a set of his own. Well, here's the bad news....the frequency range is indeed 450 transmit from the base and 230 from the handset, reverse for the receive frequencies. This of course puts this outside the GMRS band and in the case of the 230 mhz band into some part of the aircraft communication band of frequencies. I do not have the exact frequencies in front of me at this moment but I have been for warned that by using these new toys of mine I would be infringing upon part of the Private Radio Service in the 450mhz range and, as mentioned, part of the aircraft comm band in the 230mhz range. So things look a little bleak as far as using this stuff in the US is concerned."

Are you and the mods new here or something?

Don't even go there.

Re:Sweet!

[budgenator]

It operates in a licensed part of the RF spectrum; if operate this in that portion of the spectrum without a license, the FCC can and has fined people $10,000.00.

Released: February 26, 2004
By the District Director, Philadelphia Office, Enforcement Bureau:

I. INTRODUCTION
1. In this Notice of Apparent Liability for Forfeiture ("NAL"), we find that Best Wok has apparently violated Section 301 of the Communications Act of 1934, as amended (the "Act").[1] The violation occurred because Best Wok operated radio transmitting equipment on the frequency 145.8376 MHz without a license issued by the FCC. We conclude that Best Wok is apparently liable for a forfeiture in the amount of ten thousand dollars ($10,000). ...

At 11:30 a.m. on February 28, 2003, the agent entered Best Wok and inspected the radio transmitting equipment in the presence of the restaurant manager, Sae C. Hauwo. The agent found that Best Wok was operating a long-distance cordless telephone system. The system was comprised of a base unit that was located under the counter of the restaurant and a mobile unit that was in Hauwo's vehicle. There were no identifying markings on the mobile unit, but the base unit was marked with the Model Number GSM WLT-988. The FCC agent used frequency-measuring equipment to determine that the base unit actually operated on the frequency 145.8376 MHz and not the frequency 145.835 MHz as specified in the complaints. Hauwo stated that he installed the long-range cordless telephone system so that his employees could answer customers' telephone calls while making deliveries in their vehicles. Hauwo stated that he purchased the long-range cordless telephone system in another country and brought it into the United States to operate at the restaurant.

You need to be very careful when purchasing RF equipment outside the US; that it's legal inside the US. A mistake can be expensive!