I am considering submitting a paper on this topic to the <a href="http://2013.wirelesssummit.org/content/deadline-extended%E2%80%9430-days-left-submit-proposals" target="_blank">Int'l Summit for Community Wireless Networks</a> conference, being held this October in Berlin. Feel free to respond with comments, criticisms, and witticisms!<br>
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<br>Short TL;DR version: low-cost solar/battery powered wifi mesh to let folks with smartphones and laptops map out / organize / access resources in their neighborhood, for semi-casual use during disaster recovery.<br><br>
Longer version ...<br>
<br><div class="gmail_quote">Recent discussion with another St. Louisian pointed toward using the <a href="http://tidepools.co/" target="_blank">Tidepools</a> application to enable users (accessing Tidepools via smartphone wifi) to announce and locate resources and exchange messaging within a neighborhood-wide wifi mesh, say something on the order of 5 square miles for an initial deployment.<br>
<br>In particular, we were curious whether a <b>10 or 20-node rooftop mesh powered entirely by solar/battery</b>, and with a local Tidepools server running in that mesh, might make itself handy to folks recently deprived of electrical power, phone, and other utilities. Using the mesh could be further incentivized by also providing limited (~1Mbit/s) Internet access, to the extent feasible, such that disaster victims could keep up correspondence via email, Facebook, Twitter, etc. Furthermore, some of the roof nodes could have additional hardware to provide <b>5Volt cell phone charging ports</b> at ground level, powered by excess capacity in the node's solar/battery package. Also, we assume this mesh would operate 24/7 anyway, i.e. also during non-emergenies, to better familiarize neighborhood residents with its presence and let them pre-populate the Tidepools map, if desired.<br clear="all">
<br>What I'm curious about is the feasibility of constructing combined antenna mast + solar panel assemblies that rest on rooftops, anchored by cinderblocks, with sufficient rigidity/balast to withstand ~60mph wind w/o damage or significant misalignment. And for less than 500$US in materials per rooftop node. The wifi hotspots themselves create very little wind loading, so I think a key detail is doing cheap/secure mounting of the solar panel. Likewise, I would expect to site rooftop nodes such that a 20-node mesh could continue to operate if even 30% to 40% of the nodes were knocked offline (e.g. from localized tornado/microburst damage).<br>
<br>This proposal would leverage heavily off the development recently put into the <a href="https://commotionwireless.net/" target="_blank">Commotion Wireless</a> firmware and <a href="http://tidepools.co/" target="_blank">Tidepools</a> software developed by the conference organizer <a href="http://oti.newamerica.net/" target="_blank">Open Technology Institute</a>, along with the extreme low-cost outdoor mounting techniques I've been developing via <a href="http://gowasabi.net/content/your-rooftop">WasabiNet</a>.<br>
<br>Your thoughts?<br><br>Finally, below is a quick breakdown I made for building a solar/battery-powered roof node with less than 500$US of materials. Considering that the wifi hotspot itself draws less than 20W, further costing-down is possible. Specifically, a smaller solar panel and smaller 12VDC/24VDC converter should be doable.<br>
<ul><li>Ubiquiti Nanostation Loco M2 (runs on 24VDC) - $50<br><a href="http://shop.bizsyscon.com/ubiquiti-nanostation-loco-m2-outdoor-mimo-2x2-802-11g-n/" target="_blank">http://shop.bizsyscon.com/ubiquiti-nanostation-loco-m2-outdoor-mimo-2x2-802-11g-n/</a><br>
<br></li><li>60W 12V Solar Panel - $120<br><a href="http://www.amazon.com/Solar-Panel-Crystalline-Energy-Controller/dp/B005HXFWM6" target="_blank">http://www.amazon.com/Solar-Panel-Crystalline-Energy-Controller/dp/B005HXFWM6</a><br>
<br></li>
<li>12VDC/6Amp solar charge controller - $50<br><a href="http://www.amazon.com/SunSaver-Charge-Controller-12V-6A/dp/B002MQL6L2/ref=sr_1_11" target="_blank">http://www.amazon.com/SunSaver-Charge-Controller-12V-6A/dp/B002MQL6L2/ref=sr_1_11</a><br>
<br></li><li>OR Cheaper 12VDC/7Amp solar change controller - $20<br><a href="http://www.amazon.com/Sunforce-7-Amp-Charge-Controller/dp/B0006JO0XI/ref=pd_sim_sbs_hi_5" target="_blank">http://www.amazon.com/Sunforce-7-Amp-Charge-Controller/dp/B0006JO0XI/ref=pd_sim_sbs_hi_5</a><br>
<br></li><li>9-12VDC to 24VDC step-up converter - $120<br><a href="http://www.dxengineering.com/parts/sxa-06760" target="_blank">http://www.dxengineering.com/parts/sxa-06760</a><br><br></li><li>12V Golf Cart battery - $20<br>
<a href="http://www.ecomelectronics.com/prodinfo.phtml?id=2102397" target="_blank">http://www.ecomelectronics.com/prodinfo.phtml?id=2102397</a><br>
<br></li><li>DIY mounts made from cinderblocks, treated lumber, conduit, misc parts - $30<br><a href="http://goo.gl/62jYJ" target="_blank">http://goo.gl/62jYJ</a><br><a href="http://goo.gl/eU53G" target="_blank">http://goo.gl/eU53G</a><br>
<br></li><li>~50ft of shielded cat5 cable (from $150 spool of 1000ft) and ~100ft of ground wire - $20<br>
</li></ul>Total materials: $410 per rooftop node (or $380 with cheaper charge controller)<span class="HOEnZb"><font color="#888888"><span><font color="#888888"><br></font></span><br clear="all"></font></span></div><span class="HOEnZb"></span><br clear="all">
</div>-- <br>Ben West<div><a href="http://gowasabi.net" target="_blank">http://gowasabi.net</a><br><a href="mailto:ben@gowasabi.net" target="_blank">ben@gowasabi.net</a><br>314-246-9434<br></div>