NirusLaboratories
E2Test chambers
ACTIVE 03/ 16

Radio without a network

Test chamber 03. Please wait for the radio signal.

Radio without a network

Small radios send each other text messages, without internet and without a mobile network. Every device passes on whatever it hears, and so a network forms that carries itself: a mesh. We use LoRa radio and the free software Meshtastic for it. A bridge, built here in the lab, brings this radio network into the family chat.

Internet neededno
Frequency868 MHz
ChannelLongFast
Bridgehome-made
RadioLoRa
SoftwareMeshtastic

Experimental setup

  1. 01
    The mesh. Meshtastic transmits with LoRa in the licence-free 868 MHz band. LoRa is slow but reaches far. When a device hears a message, it sends it a little further on, until it arrives.
  2. 02
    The node in the house. A radio at home listens in and reports everything it receives to the lab.
  3. 03
    The bridge. mautrix-meshtastic, written here in Python. Every radio becomes a contact of its own in the chat, with its radio name; the radio channel becomes a chat room, direct messages get rooms of their own.
  4. 04
    And back. Whatever you type into that room in Element X goes out over the node in the house and onto the air.

Evidence

On the roof: the node in a weatherproof box on the mast
On the roof: the node in a weatherproof box on the mast
A Meshtastic radio in a printed case
A Meshtastic radio in a printed case
The radio node in its weatherproof box, still open
The radio node in its weatherproof box, still open

Why?

Radio needs no network. No mobile mast, no fibre, no data centre. When everything else falls silent, the mesh keeps transmitting.

And it is simply lovely when a message wanders across the area over strangers’ radios and then turns up between the family photos in the chat.

Test result

Operational, in both directions. Text only, no pictures: radio is patient, but not fast.