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Guides · Clubs · 9 November 2026 · Thomas Schüller

Radio at events without mobile coverage

How timing and checkpoint reports work in the terrain without a mobile network and which rules apply to licence-free radio bands.

Forest runs, hill races or orienteering events often lack mobile coverage. Small radio nodes in the licence-free band around 868 megahertz can then pass on split times and short messages over several kilometres, also via a chain of relays.

Rules of licence-free bands

The bands can be used without an individual licence but within limits: the European Commission decision on frequency use and the standard EN 300 220 set transmit power and duty cycle, one percent in many sub-bands. Sending many messages quickly hits these limits.

Plan instead of hope

How long a message is on air depends on the radio settings; the chip manufacturer's design guide gives the formulas. From this follow the number of messages, channel load and relays needed. A field test on the real course does not replace the calculation, and the calculation does not replace a field test.

With radio planning

The tool calculates airtime, channel load, range and relay chain and guides through the field test. For safety tasks at events it does not replace coordinated emergency communication.

Key point: Licence-free bands limit power and airtime: calculate first, then test on the course.

Open the tool

References

  1. ETSI (2018): EN 300 220-2 V3.2.1: Funkanlagen geringer Reichweite im Frequenzbereich 25 MHz bis 1 000 MHz, Teil 2: harmonisierte Norm für nicht spezifische Funkanlagen. European Telecommunications Standards Institute, Sophia Antipolis.
  2. Europäische Kommission (2006): Entscheidung 2006/771/EG zur Harmonisierung der Frequenznutzung durch Geräte mit geringer Reichweite. Amtsblatt der Europäischen Union L 312, in der geltenden Fassung.
  3. Semtech Corporation (2013): SX1272/3/6/7/8: LoRa Modem Designer's Guide, AN1200.13. Semtech, Camarillo.
  4. Meshtastic-Projekt (2026): Meshtastic Documentation: Radio Settings; LoRa Configuration; Quelltext der Firmware (RadioInterface.h). meshtastic.org und github.com/meshtastic/firmware, abgerufen 23.09.2026.