This is why departments concerned with the security of their radio systems need to go proprietary digital and/or encrypted.
On our digital TRS, radios cannot join the system or even receive traffic without being logged in and authenticated to the radio system. Each radio has its own IP address and 10- digit ID. Legit subscriber radios can be shut down OTA as well as GPS tracked if stolen. A log in password can also be required when powering the radio on and a password is required to enter encrypted TGs.
For a lower budget department, they should consider MotoTRBO or NXDN with enhanced 40 bit encryption.
Dispatch can be digital in the clear with all TAC/ops channels encrypted.
Yes, of course, because we all know that an encrypted digital system no longer follows the laws of physics. It will work no matter what, just because. That's what the OpenSky salesman told you so it has to be truth, right?
Honestly I don't necessarily have an issue with OpenSky itself, just the whole firestorm that usually surrounds it. The system itself is very good at showing just how egotistical, ignorant, and downright stupid many people are that have control over public safety agencies. As for the system itself, it may work or it may not. Nobody actually knows. There is absolutely zero factual information available to the public from inside an OpenSky system that an informed individual could use to understand the issue. It's all just political crap.
Back on topic, as I've mentioned before, anyone can interfere with and cause disruption of on scene radio traffic no matter what kind of system. Conventional, trunking, analog, digital, encrypted, they are all vulnerable. All it takes is a few skills and some brain power. Although a little more difficult, wide area communications can also be hindered in a lot of cases. It's actually a plus when digital is being used because it's less obvious that interference is even occuring.
Spread spectrum is one way effectively eliminate this ability, but how many public safety agencies use such things?