Teensy 3.6 + LoRa 868MHz
The Adafruit LoRa Transceiver working on the 868MHz frequency. Bandwidth 125kHz and Spread Factor 7. 2 to the power of 7 = 128
Not using a wireless access network.
868MHz radio frequency is license exempt in the UK, but not without rules.
The script works in raw transparent mode with no addressing where bytes are transmitted as is with no checking. All receivers will pick up the message.
Please remember this is a public wavelength and we should aim to use less than 1% of the airspace. Airtime calculator