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Comment by erichocean | Hacker News Reader

You can do the same thing with Bluetooth LE, which everyone already has.

Low-bandwidth, but doesn't require any "human in the loop" to establish the mesh.

Bluetooth LE is aiming at something slightly different. When people say several kilometres with LoRa, they do mean in actual real-world applications.

Two LoRa transceivers with dinky antennas indoors will do > 1 km in a suburban environment. With a well-sited outdoor antenna for one of the transceivers that will increase to 5+ km. Two well-sited outdoor antennas can do 20+ km if they have line-of-sight.

There's nothing else quite like it at the moment. Cellular networks are close, but higher bandwidth, power, and of course, licensed spectrum. One could cover an entire large city with a LoRa network with a dozen well-placed nodes. Its most common application to date is along those lines, with utility meters and such.

I thought this thread was about trying mesh networking at a festival. Hence my suggestion to give Bluetooth LE a try.

LoRa can get you tens of kilometers line of sight, and sometimes over a hundred. What kind of reasonable distances can one get with BLE?

BLE Long Range mode can get somewhat over a kilometer line-of-sight, open-field range.

Is that something a typical phone can do though? Is it just a bluetooth config thing that a phone typically has access to modify, or is BLE Long Range a specific set of electronics/antennas that you won't find in your spare Samsung device?

I'm not a cell phone expert. Some, maybe most, recent cell phones should be able to do BLE LR with their bluetooth radio. It is a specific modulation scheme and it does require the BLE transmitter to be capable of particular power levels. It does not require a special antenna.

“My car can go 450 miles per hour 0-60 in 1.7 seconds”

Well cool story bro but the speed limit is still 65. LoRa is an amazing technology for exactly what you describe but festivals are basically “I have very little line of sight but a fuckton of devices.”

This leads to two different solutions, high bandwidth short wave communication bouncing between everyone, and putting towers above everyone which is what cell companies do. Ground to ground LoRa is neat but not necessarily better.

I've used Meshtastic as small (5000-ish person) festivals, and even with higher bandwidth settings and stock rubber ducky antennas, ground to ground ranges through trees and people of around 1km worked just fine (with the expected shadows behind hills). This was only a small number of devices, I have no idea how badly performance would drop off if 10% or 50% of the attendees were trying to tx/rx Meshtastic or LoRaWAN signals.

LoRa is designed to handle hundreds of devices in the same area since the commercial use case is densely deployed nodes. The spreading factor is orthogonal so it is able to multiplex in the same frequency assuming your data rate is constrained enough for the largest spread factor.

There's a bit more on involved with gateways and coordination that you don't get in P2P mode but the PHY has the pieces you need I'd you wanted to do something similar.

I wonder how hard it would ve to extend the Meshtastic code to send data via BLE phone to phone as well as LoRa.

It's usually done on an ESP32, so fixed repeaters can already handle it, and it would let you try it out without actually having the hardware.

100m vs up to 8km...

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