Additionally, can you really rely on them when the building is on fire and melts the coax, etc? Then what? 2 cans and a string?
I won't touch on the annoyance with the NFPA, other than I agree with some of what you are saying. I'll also add that most of us don't have the authority to overrule the local fire inspector. So, like most things, we have to play nice.
As for fire melting the coax, the rules are the coax is required to be in conduit. Equipment rooms must be fire rated. 24 hour battery backup is required. Alarming must be included to alert of failures, malfunctions, etc. Usually there is also a requirement for a master "kill switch" on them so the fire department can take them out of service if they start causing issues.
As for self oscillation, many of the systems I've looked at monitor for that and will shut down on their own.
Of course protecting coax in conduit doesn't do anything for the antennas. Most of the indoor antennas I've seen sold for this purpose wouldn't last more than a few minutes if exposed to a fire.
Add in that any fire ground radio is usually simplex, it certainly does leave you scratching your head over this.
We're approaching this as a head end type system at work. We enjoy a robust fiber plant, so hauling the signals around to individual buildings isn't an issue. We're already running our fire alarm system over fiber.
We're also looking at this as a way to improve coverage for law enforcement. Of course they don't need the fire rating, but we'll put it in as one complete system.
Instead of these insane requirements, each structure should be handled on a case by case basis and instead of having the building owner pay 50-100K dollars on a BDA, money should go to the city for communications upgrades. The reason being, that 100K if spent correctly may cover 20 buildings or more with decent RF coverage if the system keeps getting enhanced, and it'll all be city owned.
It is done on a case by case basis. The systems only need to be installed if they don't have sufficient radio coverage inside the building. Yeah, the radio system should have enough design in it that this isn't an issue, but that doesn't take into account new energy efficiency rules regarding "Low-E" glass, steel reinforced concrete, all those other things that block RF so well.
BDA's are generally frowned upon by those in the know, but for some cheap installers, they are the solution that gets chosen. Most building owners/architects, etc. don't know the difference. All they know is that the fire marshal says they gotta do it.
The fire code thing aside….
I've talked with a few industry leaders and one area that is being looked at is how to better approach this. Most radio guys know that in-building coverage systems are expensive, fragile, are sources of noise, etc.
One idea that is getting tossed about (again, NOT fire service related necessarily) is to develop an add on to the 802.11 standard for WiFi systems that requires (or strongly encourages) a specific public safety SSID that would allow the new crop of WiFi/LTE capable public safety radios to authenticate with the system automatically and access their radio system that way. It would be a much lower cost solution, serve more people (potentially).
Of course there would be a lot of challenges with that. People would abuse it. People would hack it. I'm sure the amateur radio "emcomm" guys will demand ham radio access, etc.
But I digress.
Yeah, it's an expensive solution. They are risky if not done right. The real challenge is the energy efficient building materials that are causing this.
