While the M17 may sound like a new type of automatic rifle (as it actually is), we were thinking of an open source project to create ham radio. Instead of paraphrasing the goals of the project, we will simply quote them:
The goal here should be to launch our own protocols from the air, replace DMR, Fusion, D-Star, etc. To do this, it is not just good enough to be open, but must be legally competitive.
Like some other commercial protocols, the M17 uses 4FSK along with error correction. The protocol allows encryption, streaming and encryption of call signs in messages. There are also provisions for framing IP packets for data transmission. The protocol can process voice and data in a point-to-point topology or broadcast.
On the hardware side, TR-9 is a UHF laptop that can use FM voice or M17 with up to 3 watts. The RF part uses the ADF7021 chip, which is specially designed to make 4FSK. There is also an Arm CPU to handle digital work.
We were struck by the similarity of the TR-9 with a mobile phone, as it has an LCD display, SD card slot and 9DOF sensor. Maybe some open hardware cell phones and open hardware ham radios might find common ground.
It’s pretty ambitious, but overall, small ham platforms are revived. Availability of high quality RF components available as chips makes a big difference.