To clarify, Dallas Police primary patrol and some other front line units use the 12 UHF frequency pairs. To say the system is 50 years old simply because some of the frequencies have been in use that long is not really accurate. Using the criteria that the age of the frequencies in use determines the age of the system means many recent system upgrades, including P25 upgrades, simply wouldn't count if the same freqs were used.
The current UHF system has been upgraded many times most recently the narrow-band mandate. Dallas Police are actually spread across three systems:the UHF conventional, an 800 MHz type II and a 700 MHz P25. Four systems if you count the MDT channels. All mobile and portable radios were recently replaced with dual band units and programmed on all three systems, as well as, regional systems. I believe they are also programmed with interop and 700 MHz itinerant channels.
The RFP is to finish out the 700 MHz P25 system then migrate the 800 MHz system into it. One option would be migrate the UHF portion and built out as a UHF trunked layer. But, I also have no real problem with using as it is for other reasons, Perhaps adding additional UHF pairs. I would also say put two radios in each mobile.
They really could have used an Ops 1, Ops 2, and Ops 3, etc. last night. It was harrowing listening.
Russell