Lora-based device-to-device smartphone communication for crisis scenarios [pdf]

Instead of a trivial use-case of existing technology it would be far more beneficial to model (1) RF subscriber characteristics and how an unmanaged network of point-to-point devices can support crisis communications when a potentially (very) large number of devices can flip over to long-range point to point. How is congestion managed and mitigated? how is available spectrum, channel space and bandwidth most effectively used? And (2) The paper mentions an upstream message board and the underlying networking features provided by DTN7 describe a range of routing protocols. If nodes are taking part in a self-organising mesh network that can route in and out to central services then the management of layer-1 &amp; layer-2 is crucial to maintain a working network. It doesn&#x27;t model any of the characteristics of the medium and any strategies for how the underlying physical characteristics can be leveraged to support a mesh.<p>LoRa is excellent at long range, but with Long Range transmission comes a greater opportunity to interfere with other transmissions. Sure you can reach a long way so a low number of rural casualties can be serviced effectively, but what happens when you have a dense urban scenario and there are 10&#x27;s&#x2F;100&#x27;s&#x2F;1000&#x27;s of nodes all hitting refresh on twitter and they are all interfering with each other and the few low-bandwidth gateway nodes are attempting to carry the traffic?

Mostly what we need is fewer restrictions on some better radio frequencies. Legalizing encrypted Ham radio would be a good start. If there was an ecosystem of infrastructure around those frequencies, we would have no problem whatsoever building robust mesh networks with higher bandwidth that could operate uninterrupted through crisis scenarios.<p>As it is, we&#x27;ve been left with scraps; and this article describes an amazing tool which shouldn&#x27;t have to exist.

This sounds similar to this project: <a href="https:&#x2F;&#x2F;www.meshtastic.org&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.meshtastic.org&#x2F;</a> which was featured on HN a few weeks ago.<p><a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=22540066" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=22540066</a><p>I think selling it as a communicator for skiing&#x2F;hiking is maybe a better idea than as a disaster radio, solely because a disaster radio is never really going to be used. If it&#x27;s a useful, well used system that happens to be highly resiliant, that makes it much more likely to be available when a disaster hits.

This sounds quite similar to GoTenna, which was founded back in 2013 and has had multiple successful kickstarters.<p><a href="https:&#x2F;&#x2F;gotenna.com&#x2F;" rel="nofollow">https:&#x2F;&#x2F;gotenna.com&#x2F;</a>

Sudomesh has been working on one of these devices, disaster radio: <a href="https:&#x2F;&#x2F;disaster.radio" rel="nofollow">https:&#x2F;&#x2F;disaster.radio</a>

So... what exactly is the crisis scenario this is modeled for?<p>I can&#x27;t come up with a reasonable situation where mobile networks are completely f*cked, yet my smartphone is still running medium- to long-term. Maybe I&#x27;m not creative enough.<p>(The only thing that comes close is a large-scale power outage, but then after a day or two my smartphone battery is dead too. Also, the same measures to revive the smartphone [solar backup, generators, etc.] can also be used to revive the mobile network...)<p>[Add.: what definitely makes sense is a _dedicated_ LoRa-based emergency network, which uses dedicated user agents with low power draw and long-term batteries. Just ditch the smartphone?]

&quot;LoRa+WiFi ClusterDuck Protocol by Project OWL for Disaster Relief&quot; <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=22707267" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=22707267</a><p>&gt; <i>An opkg (for e.g. OpenWRT) with this mesh software would make it possible to use WiFi&#x2F;LTE routers with a LoRa transmitter&#x2F;receiver connected over e.g. USB or Mini-PCIe.</i>

I don&#x27;t understand what the contribution of this paper is. The most important thing, a scability test, is missing. You don&#x27;t need 16 pages to describe a LoRa-based device-to-device messaging application.

I wonder when smartphones will start to support LoRa without external hardware.

happy to see this. as a rf tech, lora was promising when i first ran into it cira 2014&#x2F;15