LoRa/Meshtastic

[Cuda416]

If you aren't familiar LoRa is a long range low bandwidth radio communication protocol which is leveraged by Meshtastic which is a firmware that you load into various iot devices that have a lots chip and antenna. Meshtastic creates a mesh network by communicating with other Meshtastic devices and establishes a communication network that doesn't require any other infrastructure.

I've been meaning to venture into this realm for a while and finally got device to try it out. So far it's interesting and I'm finding local nodes around me pretty easily.

Just wondering if anyone else is using or messing with these? There's also a plug-in for ATAK.

 

[67Dart273]

LoRa - Wikipedia

en.wikipedia.org

"LoRa uses license-free sub-gigahertz radio frequency bands EU433 (LPD433) or EU868 (863–870/873 MHz) in Europe; AU915/AS923-1 (915–928 MHz) in South America; US915 (902–928 MHz) in North America; IN865 (865–867 MHz) in India; and AS923 (915–928 MHz) in Asia;<a href="LoRa - Wikipedia"><span>[</span>8<span>]</span></a> LoRa enables long-range transmissions with low power consumption"

======================================================

I don't know why they keep calling this "long range." This is up well into UHF. The higher the frequency, the more path loss you have, caused by, weather, foliage, and general terrain, and of course hills. These frequencies are VERY much more "line of site" than the lower VHF frequencies, say, 30--100mhz. Even signals into the 2 meter amateur radio band (144-148) can and do bounce and skip here and there. At 800-900? Uh, no. STRICTLY line of sight

Path loss is a big thing, and what that means is, if you take a transmitter, with say, a unity gain antenna system, and leaving the power at a fixed level, you start raising the frequency. At some point early on, you will be able to MEASURE a signal loss. Same power, same antenna height, same antenna gain.

"Everybody" used to think that "all" the digital TV signals were going to be UHF instead of VHF. This ain't so, and IN FACT the TV broadcasters would pretty much LOVE to be on VHF. First, the transmitters are more efficient at lower freqs, meaning, the power wattage total that you are paying at the meter nets you less useable power coming out of the feedline at higher and higher freqs. And as I just said, the path loss is greatly increased, meaning you need higher gain, taller antennas and or more transmitter output power to obtain the same geographical coverage on UHF, as you had on VHF

 

[Cuda416]

Yeah these rely heavily on line of sight but they can reach out for a couple of miles each. People are putting them on the tops of mountainsz large hills, buildings and towers. Not perfect but good to have in an emergency situation.