Fire standards associations have recommended fireground/"tactical" channels be clear analog simplex as a safety measure. This stems from, among other incidents and possibilities, a situation in NYC (or surrounding area, I forget which) a number of years ago where a FF in distress on a digital and/or trunk system could not be heard by people directly outside the fire structure but was picked up by scanner enthusiasts and/or dispatch miles away.
Interoperability (interagency communication) channels in the 700 MHz chunk of spectrum allocated for public safety have been mandated to clear APCO Project 25 conventional, either simplex or repeated. This is for purposes of spectrum efficiency and choosing a common standard which it is likely most agencies will support.
In this region, we have some agencies on 800 MHz trunked (with some simplex fireground channels); some VHF conventional analog repeater/simplex; some UHF conventional analog repeater/simplex; some VHF NXDN repeater; some VHF TRBO repeater (two separate systems of that, to boot). In order to communicate on a joint incident, users have to swap radios (or make a policy of carrying each others' radios on a regular basis). This is far from ideal and goes against the recommendations of CITIG and NPSTC.
Yes, analog simplex is interoperable. But doesn't that negate the whole point of switching out your entire radio system for whatever the salesman said is the latest and greatest?
As for "going MotoTRBO is cheaper than going P25", that may be true, but I view that kind of thinking as being identical to the guy who asks "what's the cheapest oil I can get for my car?". If you get the cheapest thing available, you will suffer for it down the road.
Put it this way. If it was such a great deal to get a DMR system, and yet in order to talk to anyone else in the region, you have to switch off of that DMR system to analog, where is the benefit?
I can concede for some agencies that realize some benefit by using a TDMA DMR system to allow fire, bylaw, and public works to share the same frequencies simultaneously - something that has happened with both the TRBO systems in my area, far as I know. They can maximize their system by repurposing the tower sites that used to be for each of the three separate agencies, as nodes in the DMR "trunk" system, for all three to use together.
DMR, in my opinion, is fine for an agency that does not do any communication beyond its own realm. That is, the power company that only talks to "itself"; the public works department that never needs to talk to anyone else; and so on. But for public safety agencies, which by their nature have to interoperate on a daily basis, IMO buying DMR paints them into a corner in which there are only two ways out - forcing the neighbors they need to interoperate with into spending money buying equipment to work on the agency's preferred flavor of DMR, or switching to analog to talk to one another, thus forsaking all the features that supposedly make DMR better than everything else on the market.
