Decoding Data-Only Transmissions?

[Gilligan]

I've been running Unitrunker on my local P25 system for a year and a half. There are two talkgroups that I thought were unused because there was no voice activity on them. Both talkgroups have about 25-40 radios continuously affiliated with them, and after watching Unitrunker activity, I realized that the radios were using these talkgroups to send data packets. My first thought was that each one may have been located at a first station and being used for some kind of alerting or something. However, our county uses two-tone paging for much of that. The talkgroups are within the range of what is normally fire department talkgroups, so I'm wondering if it could be some kind of MDT signals? I also notice some of the police and sheriff vehicle radios are sending out data packets here and there. Is there any way to decode the textual data that they are sending, like the raw control data is currently decoded?

 

[cpetraglia]

If they are MDT/CAD comms, there is no way to decode. They are encrypted or otherwise protected. I have noticed Data on my P25 system going back and forth with radios I have already IDed.
If you do figure it out, I think you'll be the first.

Chuck