They're often licensed even if they use a frequency in the ISM Band range so if you live in the USA you can search these ranges in the FCC ULS and limit it to your city to find if there are any. My local department has one in the 2.4 GHz, I got to see it demonstrated at a public event once.
It's often proprietary digital these days to help deal with in-band interference better and sometimes encrypted as well. When I looked up the system on the manufacturer website that was indeed the case here.