Jailbreaking DMR

One of the discussions that came out of class after the antenna building and demonstration was a quick rundown on some of the digital options available. DMR and some of its lesser-known offshoots can be very interesting, offering a big step up in privacy and security over your average Bubba. While it won’t mask your signal from interception and most newer and higher-end scanners can easily decode the audio, when used in conjunction with some of the methods taught in the RTO course it becomes another layer of capability.

Many look down on the lower-end DMR radios especially in areas with heavy repeater traffic. This is largely because the radios themselves have had issues in the past with the way in which data is sent between the two generations of DMR technology. Mike Bishop wrote a great rundown of how it works. For simplex operations this is irrelevant. But the neat thing about inexpensive kit is that it gives a testbed for experiments, especially when working with open source and modifiable firmwares.

The hack itself of these radios has been around for a while now but it’s an important one to note for anyone who’s considering these or is currently running them. The original mod allows monitoring of all talk groups and color codes, which has great utility in and of itself, and the ability to configure your own firmware as documented on Github. With a little work and some field time, it might be a good option for inter-squad communications.