Columbia Gas of Virginia quit using their UHF P25 system a few years ago. They use nothing except cellular phones and their MDT devices also connect via cellular (I think). I am not sure about the other Columbia Gas Companies, Mass, MD, Ohio, PA and I am probably missing a few other states they operate in. Their original system did voice and data on the UHF P25 system with voice having priority over the data. The original system had a cable from the Astro Spectra mobile radio with a DB-9 connector to plug into the computer's comm port. They eventually updated to a usb connection.