Have you heard of M17 Protocol ?

M17 is a new digital radio protocol in development as an alternative to those currently available, with freedom in mind. Freedom in the code, protocol, voice codecs, and hardware. The goal is to provide a better option for digital radios in the future.

The M17 Working Group is a team of several people from around the world. Headed up by Wojciech (SP5WWP) in Poland, there are several other Amateur Radio operators involved - putting their skills to work with the desire for a more free and open digital radio protocol that can be used world wide!

“The goal here should be to kick the proprietary protocols off the airwaves, replace DMR, Fusion, D-Star, etc. To do that, it’s not just good enough to be open, it has to be legitimately competitive.”

M17 is an RF protocol that is:

• Completely open: open specification, open source code, open source hardware, open algorithms. Anyone must be able to build an M17 radio and interoperate with other M17 radios without having to pay anyone else for the right to do so.
• Optimized for amateur radio use.
• Simple to understand and implement.
• Capable of doing the things hams expect their digital protocols to do:
  • Voice (eg: DMR, D-Star, etc)
  • Point to point data (eg: Packet, D-Star, etc)
  • Broadcast telemetry (eg: APRS, etc)
  • Extensible, so more capabilities can be added over time.
• M17 standard uses 4FSK modulation running at 4800 symbols/s (9600 bits/s) with a deviation index h=0.33 for transmission in 9 kHz channel bandwidth. Channel spacing is 12.5 kHz.
• M17 adopts Frequency Division Multiple Access (FDMA) instead of Time Division Multiple Access (TDMA), so M17 is not compatible with DMR. 

and their OpenRTX is a free and open source firmware for digital ham radios, top-down designed with modularity, flexibility and performance in mind. 

Currently OpenRTX is being actively developed support our Retevis RT3S. If you want to learn more, please check this link: https://openrtx.org/#/mduv380_mods