Radio configuration of the MeshCore repeater (the fox)
Avoid using your local MeshCore frequency, so as not to disturb the local mesh.
For exemple, in France the local Mesh is configured on
EU/UK (Narrow) 869.618 MHz / SF8 / BW62.5 / CR8
A node on this mesh transmits at 869.618 MHz with a bandwidth of 62.5 kHz. The LoRa signal therefore occupies approximately 869.587 – 869.649 MHz (±31.25 kHz around the center frequency).
We stay within the high-power SRD band 869.400 – 869.650 MHz, which allows up to 500 mW (27 dBm) ERP with a 10% duty cycle. This 250 kHz band provides exactly four non-overlapping 62.5 kHz channels:
| Channel | Frequency range | Usage |
|---|---|---|
| 1 | 869.400-869.462 | Free |
| 2 | 869.462-869.525 | MeshCaching |
| 3 | 869.525-869.587 | Free (guard channel) |
| 4 | 869.587-869.650 | Local MeshCore mesh |
We select a center frequency of 869.493 MHz with a bandwidth of 62.5 kHz. This keeps our signal two channels away from the local MeshCore channel, with one empty channel acting as a guard band, so there is no spectral overlap and minimal adjacent-channel interference.
Since MeshCaching does not require long-distance message reliability, we use SF7. It ensures faster message transmission, reduces airtime, and limits duty-cycle usage.
Using CR5 makes it possible to reduce airtime without significantly impacting reliability, since MeshCaching has a limited geographical range.
Resulting MeshCaching configuration:
869.493 MHz / SF7 / BW62.5 / CR5