Given that some DMR radios have GPS, can DMR users get into using APRS text messaging? For UHF as well? How would I get started with this? My current DMR radio (PD362) does not have GPS.
DMR has built in text messaging. The interlinking network operators such as DMR-MARCS require that GPS be turned off in user radios because the data overload the network. The ham implentation of DMR is somewhat limiting compared to commercial use. I don't think any external mode of sending data (such as APRS) will be welcome in the ham DMR networks.