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<div class="moz-cite-prefix">On 12/20/2013 04:15 PM, J.C. wrote:<br>
</div>
<blockquote
cite="mid:CAHxkbY1idpJ_fq8PVonjB8jPOuNstCdk0Biiw81k1vTc4o-gEg@mail.gmail.com"
type="cite">
<div>So what if you combined that with a "mesh" aspect, and you
could create pocket stations around the city</div>
<div><br>
</div>
<div>Seems like it would make for a fun kit as well, building mini
fm transmitters & receivers.</div>
</blockquote>
<br>
I've been thinking about this as well. Folks have been working on
WiFi based mesh networks for over a decade, and while the technology
is cheap and you can use off-the-shelf components, range is limited
unless you use external antennas, maybe directional ones. But the
main showstopper is the line-of-sight requirement for larger
distances.<br>
<br>
I see Norman's point that you shouldn't upset the FCC, so maybe some
proactive screening of relevant regulations and maybe even getting
in touch with them before deployment couldn't harm.<br>
<br>
Sparkfun has some ideas for transceivers in the ISM bands around
434, 868 and 915 MHz:<br>
<br>
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<a href="https://www.sparkfun.com/categories/16">https://www.sparkfun.com/categories/16</a><br>
<br>
in particular this one looks interesting:<br>
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<br>
<a href="https://www.sparkfun.com/products/11664">https://www.sparkfun.com/products/11664</a><br>
<br>
You don't want to stream stuff in HD, do you? ;)<br>
<br>
I would be interested in a low-cost module that works down on HF
frequencies, and even though projects like the HackRF [1] reach down
to that range, they're still too expensive for mass deployment.<br>
<br>
These modules here are not open hardware, but they come closer to
the price range I have in mind:<br>
<br>
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<a
href="http://www.radiometrix.com/our-products/latest+products/Transceivers">http://www.radiometrix.com/our-products/latest+products/Transceivers</a><br>
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<a
href="http://www.kiatronics.com/rf-27mhz-fm-series-transmitters-and-receivers/fmt-2712-1-watt-27mhz-radio-data-module.html">http://www.kiatronics.com/rf-27mhz-fm-series-transmitters-and-receivers/fmt-2712-1-watt-27mhz-radio-data-module.html</a><br>
<br>
It cannot be *that* hard to develop a transceiver for 27 MHz ... but
piggybacking digital data on FM sound like a silly idea. I would
have to read up on the regulations if anything else is allowed tho
...
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<a href="http://dronepedia.com/index.php?title=Radio_bands">http://dronepedia.com/index.php?title=Radio_bands</a>
has a nice overview of ISM bands.<br>
<br>
<br>
<br>
Cheers<br>
<br>
Alex<br>
<br>
[1]
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<a
href="http://www.kickstarter.com/projects/mossmann/hackrf-an-open-source-sdr-platform">http://www.kickstarter.com/projects/mossmann/hackrf-an-open-source-sdr-platform</a><br>
<br>
<pre class="moz-signature" cols="72">--
"Those who surrender freedom for security will not have, nor do they deserve, either one."
-- Benjamin Franklin</pre>
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