Lora-based device-to-device smartphone communication for crisis scenarios [pdf]
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Re: Lora-based device-to-device smartphone communication for crisis scenarios [pdf]
#2[deleted]
Re: Lora-based device-to-device smartphone communication for crisis scenarios [pdf]
#3Instead 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 & layer-2 is crucial to maintain a working network. It doesn'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.
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's/100's/1000'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?
Re: Lora-based device-to-device smartphone communication for crisis scenarios [pdf]
#4Instead 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 effectiv…
> 10's/100's/1000's of nodes all hitting refresh on twitter
That's not going to happen with Lora. This it completely different scale of messaging. Your message is limited in bytes and takes multiple seconds to transmit. You can assume the messages will be significantly delayed if 100 people around are actively using it.
But it's designed for a specific purpose and there's no active refreshing/polling that's going to happen.
Re: Lora-based device-to-device smartphone communication for crisis scenarios [pdf]
#5Instead 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 effectiv…
> 10's/100's/1000's of nodes all hitting refresh on twitter That's not going to happen with Lora. This it completely different scale of messaging. Your message is limited in bytes and takes multiple seconds to transmit. You can assume the messages will be significantly delayed if 100 people around are actively using it. But it's designed for a specific purpose and there's no active refreshing/polling that's going to…
Exactly. How many people could this support? My guess it would be a small proportion of an urban population.
> no active refreshing/polling
Maybe not twitter specifically, but the paper mentions a centralised message board like twitter, so we can assume some sort of interactive service would be suggested.
My main point is this that for such a specific bearer (bandwidth, channel plan, duty cycle, range etc) it is important to model the capabilities. I’m not sure how well this would support a crisis (notably free of central management) when there is the potential for large numbers of nodes.
Re: Lora-based device-to-device smartphone communication for crisis scenarios [pdf]
#6This sounds quite similar to GoTenna, which was founded back in 2013 and has had multiple successful kickstarters.
Re: Lora-based device-to-device smartphone communication for crisis scenarios [pdf]
#7I wonder when smartphones will start to support LoRa without external hardware.
Re: Lora-based device-to-device smartphone communication for crisis scenarios [pdf]
#8Sudomesh has been working on one of these devices, disaster radio: https://disaster.radio
Re: Lora-based device-to-device smartphone communication for crisis scenarios [pdf]
#9Mostly 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.
As it is, we've been left with scraps; and this article describes an amazing tool which shouldn't have to exist.
Re: Lora-based device-to-device smartphone communication for crisis scenarios [pdf]
#10Sudomesh has been working on one of these devices, disaster radio: https://disaster.radio
I like the solar integration. My ideal product would be a programmable LoRa transceiver integrates into a waterproof battery bank with solar, gps and a small touch screen. Should be about the size of a large handheld which could mounted on a house, tree, mast or carry it in a pocket/bag. Apps could be, SOS messages, chat and weather information. If it’s extensible (e.g. something like an app store or package manager), I’m sure folks will dream up additional uses.
Sort of like a more hackable/accessible phone and long range radio.