• Ricardo Guzmán Christie, CD2RXU, for developing terminal and i‑gate firmware employing the compression algorithms presented in this white paper.

  • Bernd Gasser, OE1ACM, for the earliest LoRa APRS experiments and code

  • Christian Johann Bauer, OE3CJB, for the Base91 geolocation compression algorithm

  • Peter Buchegger, OE5BPA, for providing a tracker and i‑gate firmware as open source code, in a handy PlatformIO environment, with over-the-air (OTA) i‑gate updates. This was the ideal starting point for running LoRa frame compression experiments.


  • Serge Y. Stroobandt, ON4AA, for devising the protocol and Python codec algorithms, as well as initiating this project by writing the protocol white paper.

  • Folkert Tijdens, PA0FOT, for contributing codec.cpp and asking the right questions, rendering this document more scholarly

  • Matthias Brändli, HB9EGM, for contributing the Arduino C implementation of the tttt codec algorithm.

  • Pascal Schiks, PA3FKM, for providing insights about microcontroller stacks

Spectrum Selection

  • Wolfgang Hallmann, DF7PN, for informing that, in a number of European countries, the ISM‑band extends from 433.05 to 434.79 MHz.

  • Gerhard Hickl, OE3GHB, for pointing out that, in Austria, the spectrum above 439.1 MHz is receive only.


  • Erwin Fiten, ON8AR, for testing firmware and reporting on long distance car approaches to the LoRa i‑gate

  • Jan Engelen, DL6ZG, for testing firmware and providing feedback

  • Greg Stroobandt, ON3GR, for cycling around the city with a privacy invading tracker