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Communication · Digital · LoRa mesh

Mesh radio

Meshtastic / Meshcore

LoRa mesh networks like Meshtastic or MeshCore work completely without infrastructure: every device is both transmitter and relay. Messages hop encrypted from node to node – ideal for neighbourhood networks, hiking groups or as a family fallback channel. While Meshtastic floods every message through the whole network, MeshCore takes a different path: fixed repeaters form a backbone, personal devices deliberately do not forward, and messages follow a learned path instead of flooding the radio band.

Range2–10 km / hop
LicenceFree · 868 MHz
PowerBattery, frugal

How LoRa mesh works

LoRa mesh transmits small data packets over long distances at tiny transmit power. Every device is both transmitter and relay: messages are passed from node to node via store-and-forward (hops) until they reach the destination – completely without mobile network and without internet.

On Meshtastic the number of hops is limited to 3 by default (maximum 7). More hops increase the range but put more load on the network.

  • Only text, position and telemetry data are transmitted – LoRa is narrowband, no voice, no video.
  • Encryption: AES-256 with a shared key (PSK) per channel. The public default channel is effectively unencrypted – for private use, set up your own channel with your own key.
  • The more nodes there are in the region, the more robust and far-reaching the network.

What MeshCore is

MeshCore is an open-source system (MIT licence) for secure, text-based communication via LoRa radio modules – completely without mobile network and internet. It provides both the device firmware and the underlying routing protocol. The official project site is meshcore.io.

The central difference from Meshtastic lies in the routing: Meshtastic floods every message through the network (every node forwards). MeshCore instead learns a path and then transmits in a targeted way – this keeps the radio band clear and makes larger, planned networks more stable. Both often run on the same hardware but are not compatible with each other: a device carries either one firmware or the other, and the two cannot communicate in the same network.

  • Official use cases according to the project: off-grid communication, emergency and disaster relief, outdoor activities, security applications and sensor networks.
  • Firmware and routing are open source; the exceptions are the T-Deck firmware and the native smartphone apps.
  • For beginners: MeshCore is messaging-oriented – you need no radio knowledge to start, just a flashed device and the app.

The device roles – the heart of MeshCore

MeshCore thinks in roles. Which task a device takes on in the network is decided at flashing via the chosen firmware image. This role-based model is the reason MeshCore scales more efficiently than pure flooding: only dedicated devices forward, personal devices stay out of it.

  • Companion (your personal device): connects via Bluetooth or USB to a smartphone, PC or web client and is your messenger endpoint. Important: a Companion does not forward any foreign packets. This is intentional – so that dozens of handheld devices do not simultaneously flood the radio band with repetitions.
  • Repeater (the backbone): extends the range and forwards packets towards the destination – but not blindly every packet, rather along learned paths. Repeaters belong at high, well-visible locations. By default they send an identifier every 12 hours ("Flood-Advert") so the network can find them.
  • Room Server (topic/group rooms): a simple message server (BBS principle) that stores contributions and delivers them to clients afterwards (store-and-forward). Unlike normal channels, you can log back in later and pick up missed messages (comparable to a mail server). On logging in you receive the last 32 unseen messages.
  • Why this is more scalable: with pure flooding (Meshtastic) a single message triggers many redundant repetitions network-wide. With MeshCore only repeaters/Room Servers forward, and they do so in a targeted way along a path – less radio traffic, fewer collisions, more throughput in dense networks.
  • For beginners: if you have only two devices and no MeshCore users nearby, flash both as Companion and communicate directly with each other. Only when you need range does a repeater come into play.
  • Expert tip: run Repeater and Room Server on separate devices where possible. For a neighbourhood network, place a few repeaters high up and with line of sight rather than many at street level.

Routing, encryption and technology

When you send a message for the first time to a still-unknown destination, it finds its way via flooding. The destination device sends back an acknowledgement that lists all the repeaters it passed through – from this the sender learns the path. Every further message carries this path embedded with it; a repeater only forwards it if it lies on the path itself. If a path breaks, the device tries a few times and then floods anew.

  • Group or channel messages have no fixed path and are flooded – repeater operators can however limit this flooding volume.
  • The internal hop limit is 64 – in practice barely reachable.
  • Encryption: MeshCore works end-to-end encrypted (AES); every device has its own cryptographic key pair, and the identifiers are signed to prevent forgery. Groups/channels use a shared key. Caution: the public default channel uses a generally known key and is therefore effectively not private – for confidential matters, set up your own channel with your own key.
  • Supported hardware (selection): Heltec V3, RAK WisBlock (RAK4631), LilyGo T-Beam/T-Deck/T-Pager, Heltec T114, Seeed T1000-E, Station G2. The current device list is in the web flasher.
  • Apps/clients: native Android/iOS app (Bluetooth) as well as a web client for USB connection. Devices like the T-Deck can also be operated standalone without a smartphone.

Range, frequency and law (Switzerland)

In Europe Meshtastic transmits in the 868 MHz ISM band, which in Switzerland is part of the licence-free SRD range (863–870 MHz). Important: transmit power and the permitted transmit time are regulated depending on the sub-band – in the typical range 868.0–868.6 MHz, 25 mW ERP applies at a 1 % duty cycle (transmit-time limit). The firmware automatically observes these limits for Switzerland/the EU.

  • Range (experience values): in clear line of sight several kilometres up to over 16 km; in the city without line of sight often only a few hundred metres; in dense forest around 0.4 to 2.5 km.
  • What matters is the line-of-sight connection – height and antenna position bring more than transmit power.
  • Very low power consumption – a node runs for days on battery.

MeshCore or Meshtastic?

Both use the same hardware and the same band, but are not compatible with each other – a device carries either one firmware or the other.

  • Meshtastic: true ad-hoc mesh, every node forwards (flooding). Very flexible and self-organising, but more radio traffic. The largest community.
  • MeshCore: role-based – personal devices (Companions) do not forward, fixed repeaters handle the routing. More efficient and better scalable for planned neighbourhood/regional networks.
  • For beginners: start with Meshtastic – the widest adoption, the simplest app, the most tutorials.
  • Expert tip: for a permanent neighbourhood network with fixed locations, MeshCore's repeater model is more resource-friendly.
  • Both use the same 868 MHz band and mostly the same boards, but cannot communicate in the same network – they do not understand each other.

Getting started with MeshCore – step by step

  • Get a supported board (e.g. Heltec V3, RAK WisBlock, LilyGo T-Deck).
  • Via the web flasher (flasher.meshcore.io), flash the appropriate role firmware – Companion for personal devices, Repeater for the backbone.
  • Set the region/frequency to the EU preset (868 MHz) – the parameters are then chosen automatically and correctly.
  • Pair the Companion via the app (Android/iOS) or web client; for private use, set up your own channel with your own key.
  • Test the range, place the antenna high and with clear line of sight.
  • Realistic range (experience values, not guaranteed values): in clear line of sight in rural areas around 10 km, in built-up environments rather 1–3 km, from elevated locations considerably more. What matters is the line-of-sight connection.
  • Typical use cases: neighbourhood or regional network with fixed repeaters, hiking group, family fallback channel or supplement to emergency radio.
  • Expert tip: plan the repeater backbone first (locations with line of sight/height), then the network scales cleanly.

Good to know

  • 868 MHz is licence-free in Switzerland
  • Very low power consumption – runs for days on battery
  • The more nodes there are in the region, the more robust the network

Further sources

→ View matching emergency radio frequencies