Chat/text over LoRa always sounded intriguing! I'm merely a 1000km away from Sicily (which antirez say they wanna cover with the network at first), I wonder if it would be possible to do what AM radio does, bounce against the ionosphere and get huge ranges for transmission? Maybe it would need way too much transmission power? Maybe hopping all the way P2P style makes more sense, although surely would be slower.
Checkout MeshCore; we're doing 400 miles using 12 hops going from north Vancouver to Eugene Oregon https://analyzer.letsme.sh/map?lat=47.36113&long=-122.20419&...
> 400 miles using 12 hops
What's the E2E latency on that, for curiosities sake :)
6 seconds or so
Ah, that's not too bad honestly, nicely done.
I can't wait for us to somehow figure out how to connect all the various mesh-networks in the world. MeshCore is a whole continent and ocean(s) away from say Freifunk or Guifi, but would be incredible if we could figure out how to interconnect between them, so we could all talk via the already built alt-infra. Maybe the FossaSat mentioned in another comment (https://news.ycombinator.com/item?id=45806794) could finally be one option.
Can you recommend any outdoor node hardware that can provide services for both MeshCore and Meshtastic? Cost is not an issue, optimizing for “plug in and does All The Things.”
You'd need two radios, one antenna stacked on top of each other. Z offset of a minimum height of 1m/3'. In the X,Y offset of 0,0. You want high gain 8-10db antennas in this arrangement; you'd need more space between if you use lower gain antennas.
If you're looking for parts the Diamond BC920 is the best antenna. Station G2 with a $100 3-4mhz cavity filter for each frequency as well.
Not at 900MHz. Skywave propagation mode is only available under about 30MHz. Above that, the signal reliably continues on into space.
At frequencies this high, you’re realistically limited to near line of sight paths.
> Not at 900MHz
Shame, but at least now I understand why, thanks :)
> you’re realistically limited to near line of sight paths
Wonder exactly how far one would be able to get up to reach 1,000km line of sight, assuming you put both points equally far up. Guessing it's the curvature of the earth that gets in the way at that distance?
Yep. There are cubesats running LoRa payloads in low earth orbit[0], and between mountaintops, terrestrial paths of hundreds of km are possible[1].
[0] https://www.hackster.io/news/fossasat-1-an-open-source-satel...
[1] https://meshtastic.org/docs/overview/range-tests/
> Using metal tape measures to build simple quarter-wave monopole antennas is a hack to that’s actually pretty common in the small satellite community
This is just too crazy, thanks a lot for sharing these links! :)
Unlikely since the most ISM bands are UHF (EU is 868 MHz) and skywave propagation (what you’re referring to) is characteristic of HF radiation (3-30MHz). VHF/UHF radiation passes through the ionosphere instead of refracting.