Mesh Routing

Mesh routing is the set of techniques by which a network of peer radios relays each other's messages, so data can travel far beyond the range of any single transmitter and around obstacles no direct path could clear. Unlike a star network that depends on a central tower or gateway, a mesh has no single point of failure: nodes join and leave freely, and the network reorganises itself around whatever links currently exist.

Managed flooding in practice

Meshtastic, the most popular sovereign LoRa mesh firmware, deliberately avoids complex routing tables in favour of managed flood routing. Every node that receives a packet rebroadcasts it once, decrementing a hop-limit counter until it reaches zero. To prevent a storm of duplicate transmissions, a node first listens briefly; if it hears a neighbour already relaying that packet, it stays silent. The contention delay is weighted by signal strength so that distant nodes — which extend coverage most — tend to rebroadcast first, while close-in nodes that add little reach defer.

Strengths and limits

This approach needs no route discovery and adapts instantly to a changing topology, which is ideal for mobile or intermittently powered nodes. The cost is efficiency: flooding consumes airtime that grows with node density, so large meshes keep hop limits modest and payloads small. Newer firmware adds next-hop routing hints to curb unnecessary rebroadcasts without sacrificing the self-healing character.

Mesh routing is what turns individual LoRa nodes into a resilient fabric; pair it with store and forward to reach peers that were offline when a message was sent.

See presets in the Meshtastic/LoRa regions dataset.