M17 Digital Radio Protocol — History of Development

This content was generated by ClaudeAI for KJ7T on March 21, 2026

The M17 digital radio protocol has its roots in Warsaw, Poland, at the turn of 2018–2019. The project was started by Wojciech Kaczmarski (callsign SP5WWP), who was a member of a local amateur radio club involved in digital voice communications. Having experimented with proprietary systems like TETRA and DMR, Kaczmarski decided to create a completely non-proprietary protocol and named it after the club's street address — Mokotowska 17. The frustration driving his effort was clear: existing digital modes like DMR, C4FM, and others used the proprietary AMBE codec, which contradicts the amateur radio community's values of open-access technologies that encourage experimentation and knowledge sharing.

A key technical decision was the choice of voice codec. M17 uses Codec 2, a low-bitrate voice codec developed by David Rowe (VK5DGR) and collaborators. Codec 2 was selected due to its open licensing and suitability for low-bitrate digital voice applications. Rowe's work was foundational — without a truly free and open vocoder, a fully open digital voice protocol simply wouldn't have been possible. Kaczmarski took on the mission of incorporating that vocoder into a completely non-proprietary digital radio standard, and over the course of several years, the team expanded to include hams from all over the world, primarily from the USA, Germany, Italy, and Australia.

Recognition and financial support soon followed. In 2021, the ARRL bestowed its Technical Innovation Award on Kaczmarski for developing M17, a new open-source and patent-free digital radio protocol with the goal of providing a fully sustainable option for digital radios in the future. The award plaque was accepted on Kaczmarski's behalf by Ed Wilson (N2XDD), who served as Community Manager of the M17 Project. That same year, the Amateur Radio Digital Communications (ARDC) foundation awarded the M17 Project a grant of $250,000, with the Open Research Institute serving as fiscal sponsor. A second grant followed in 2022, with $228,000 transferred to the Deutscher Amateur-Radio-Club (DARC) to continue the project, especially its EU-based endeavors.

The community around M17 continued to grow and produce tangible results. The efforts of Kaczmarski and other M17 team members led to the development of DroidStar, an Android application created by Doug McLain (AD8DP), as well as software tools like mvoice and GNU Radio integration modules. On the hardware side, the project developed the Module17 modem, the OpenHT SDR handheld transceiver, and a Remote Radio Unit repeater platform. The M17 Foundation was formally established in December 2024 to provide a solid legal entity to represent and protect the interests of M17. Today, the protocol is interlinked with virtually every major digital voice network in amateur radio, and over 130 M17 reflectors exist worldwide as of early 2026.

• M17 Project official website
• M17 Foundation Wiki
• M17 Protocol Specification on GitHub
• Amateur Radio Digital Communications (ARDC)