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Radio Settings

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Meshtastic is not LoRaWAN, Helium or TTN (TheThingsNetwork). Meshtastic uses the full spectrum frequency range designated to LoRa technology per region. This allows for several hundred possible frequency channels in the US region alone.

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Power limits will generally be lifted in the software if is_licensed is set to true. See HAM Mode for more information.

Frequency Slot Calculator

Europe Frequency Bands

433 MHz

The maximum power allowed for Europe is +10 dBm ERP (Effective Radiated Power).

The band range is from 433 to 434 MHz.

There are four channels defined with the standard radio preset LongFast. After factory reset the radio will be set to channel 4 with a center frequency of 433.875 MHz.

868 MHz

The maximum power allowed for Europe is +27 dBm ERP (Effective Radiated Power).

The band range is from 869.40 to 869.65 MHz. This is less than the 863–870 MHz range defined as SRD Band, but allows for a higher ERP and a duty cycle of 10%.

There is one channel defined with the standard radio preset LongFast. After factory reset the radio will be set to channel 1 with a center frequency of 869.525 MHz.

North America Frequency Bands

915 MHz (ISM Band)

The maximum output power for North America is +30 dBm ERP (Effective Radiated Power).

The band range is from 902 to 928 MHz.

There are 104 channels defined with the standard radio preset LongFast. After factory reset the radio will be set to channel 20 with a center frequency of 906.875 MHz.

Data Rates

Considerations

Various data-rate options are available when configuring a channel and are inversely proportional to the theoretical range of the devices.

  • Spreading Factor (SF) - How much we "spread" our data over time.
    • Each step up in Spreading Factor doubles the airtime to transmit.
    • Each step up in Spreading Factor adds about 2.5db extra link budget.
  • Bandwidth - How big of a slice of the spectrum we use.
    • Each doubling of the bandwidth is almost 3db less link budget.
    • Bandwidths less than 31 may be unstable unless you have a high quality Crystal Oscillator.
  • Coding Rate - How much redundancy we encode to resist noise.
    • Increasing coding rate increases reliability while decreasing data-rate.
    • 4/5 - 1.25x overhead
    • 4/6 - 1.5x overhead
    • 4/7 - 1.75x overhead
    • 4/8 - 2x overhead

Presets

We have eight LoRa radio presets. These are the most common settings and have been proven to work well:

Channel settingAlt Channel NameData-RateSF / SymbolsCoding RateBandwidthLink Budget
Short Range / FastShort Fast10.94 kbps7 / 1284/5250143dB
Short Range / SlowShort Slow6.25 kbps8 / 2564/5250145.5dB
Medium Range / FastMedium Fast3.52 kbps9 / 5124/5250148dB
Medium Range / SlowMedium Slow1.95 kbps10 / 10244/5250150.5dB
Long Range / FastLong Fast1.07 kbps11 / 20484/5250153dB
Long Range / ModerateLong Moderate0.34 kbps11 / 20484/8125156dB
Long Range / SlowLong Slow0.18 kbps12 / 40964/8125158.5dB
Very Long Range / SlowVery Long Slow0.09 kbps12 / 40964/862.5161.5dB
note

The link budget used by these calculations assumes a transmit power of 22dBm and an antenna with 0dB gain. Adjust your link budget assumptions based on your actual devices. Data-rate in this table is the theoretical max but doesn't account for packet headers, hops and re-transmissions. Calculations based on data from the official Semtech LoRa calculator.

Custom Settings

Custom settings can be applied by using supported software.

After applying the settings, you will need to restart the device. After your device is restarted, it will generate a new crypto key and you will need to share the newly generated QR Code or URL to all your other devices.

Some example settings:

Data-rateSF / SymbolsCoding RateBandwidthLink BudgetNote
37.50 kbps6 / 644/5500129dBFastest possible speed
3.125 kbps8 / 2564/5125143dB
1.953 kbps8 / 2564/8125143dB
1.343 kbps11 / 20484/8500145dB
1.099 kbps9 / 5124/8125146dB
0.814 kbps10 / 10244/6125149dB
0.610 kbps10 / 10244/8125149dB
0.488 kbps11 / 20484/6125152dB
0.073 kbps12 / 40964/531160dBTwice the range and/or coverage of "Long Slow", low resilience to noise
0.046 kbps12 / 40964/831160dBTwice the range and/or coverage of "Long Slow", high resilience to noise

The link budget used by these calculations assumes a transmit power of 17dBm and an antenna with 0dB gain. Adjust your link budget assumptions based on your actual devices.

These channel settings may not have been tested. Use at your own discretion. Share on https://meshtastic.discourse.group with your successes or failure.

Cryptography

The pre-shared key (PSK) used by the devices can be an AES128 or AES256 sequence. Alternatively, encryption can be turned off, which may be useful if you are operating under a Ham Radio license.