

Ask HN: A free "cell phone" for use within a few miles of home? - staunch

It seems to me that I should be able to buy a two-way radio that reaches a base station at home from at least a few miles away. I should be able to hook this radio up to my internet connection and do VoIP over my existing Skype/Gtalk account.<p>a) Cell phone-like mobile (battery operated) radio (encrypted ;-D ?)<p>b) Base station at home hooked up to broadband router.<p>c) One time cost of less than $300.<p>So:<p>1) Does it exist? (I'm guessing no, so why not?)<p>2) Would it be possible to do myself without spending $1k on hardware, hacking a bunch of custom hardware/software, and getting a ham radio license?<p><i>Update:</i><p>Long range cordless phones do seem to exist, but they're not cheap.<p>Voyager SS 2600 ($1500)<p>SN 258 ($300)<p>I'm also not sure they're allowed to be used in the US unlicensed.
======
ab9rf
Assuming the US, you'll run into legal problems. None of the Part 15 (low-
power unlicensed) bands would have the range you're looking for; the power
levels are too low to give that much range. Part 97 (ham radio) wouldn't help;
there are too many restrictions on content (no encryption, no profanity, no
pecuniary interest, limits on "third party" traffic, etc.) to use ham radio
for the purpose desired. And you can't send data (other than selective calling
codes, and geolocation bursts only in the FRS) on the various licensed-by-rule
"citizen" services in Part 95.

That pretty much leaves you with having to get a business radio license ($260
per ten years minimum, plus possible additional fees), and on top of that
you'll need a someone with a GROL ($60 fee plus testing fees) to maintain and
operate it.

The only other option would be unlicensed VLF. This you could do, but there's
two problems: the antennas for VLF are huge, and the available bandwidth is
tiny. Ever used a 300 baud modem? Well, that screams compared to what you can
get out of a VLF connection: 5 baud is a fast data rate in this band.

Those Voyager units use frequencies reserved for military use the United
States. Using them in the US would be a good way to get yourself in a heap-o-
trouble.

The problem you have is that for the range you want you need to be able to
operate over the horizon. That means your receiver is going to be in one of
the transmitter's diffraction zones, which means only a fraction of the
transmitter's signal will get through. We do this all the time in radio, and
we accomplish by throwing enough power at the problem to have a received
signal strong enough to be demodulated even with diffraction losses. For the
distance your looking for, you'll need about 25 watts minimum, way more than
you can get away with in Part 15.

------
mvalente
Hack a walkie talkie ( <http://en.wikipedia.org/wiki/Walkie-talkie> ) ?

Use one as the base and get the audio in/out connected to your home PC audio
in/out.

Hacking in a tone dialer ( <http://is.gd/5EjWA> ) might also be necessary.

\-- MV

------
jarsj
I have seen geek radio pairs. The quality wasn't great and they came with many
ifs and else. Then there are legal restrictions, atleast here in India.
Checkout ThinkGeek.

As for the successful commercialization, I think it involves too many
components for ordinary people to be able to use it and customer support would
be a nightmare.

------
wglb
A ham radio license won't help, as ham radio transmissions are forbidden to be
encrypted, and there are limitations on speech, e.g., profanity, commercial
transactions.

There are unlicensed bands that are available, but again there may be
restrictions similar to ham radio, and cost might also be a factor.

------
bemmu
More than why not, I'd like to know why?

~~~
staunch
I'm almost always within a few miles of my home or office. Both locations have
high speed internet connections. Skype offers great rates on international
calls.

Just an idea, I'm not saying it's definitely a good one.

~~~
lhuang
Do you make many international calls when on the go?

I can see this being useful if you don't currently have a cell phone. If you
did, outside of cheaper international calls, it seems really redundant.

Plus if you ever traveled outside the signal radius you'll effectively have a
big lump of plastic wasting space in your pockets (on top of everything else
you carry).

All that said I think this would be a fun side-project and really with the
rise of municipal broadband and services like Fon, I can see this being
somewhat viable in the long-term.

------
jgrahamc
Does anyone else remember Rabbit?

[http://en.m.wikipedia.org/wiki/Rabbit_(telecommunications)?w...](http://en.m.wikipedia.org/wiki/Rabbit_\(telecommunications\)?wasRedirected=true)

