Will that frequency spectrum be isolated to be used by only public safety or will there by other users?
Isn't a responder keying his radio when he acknowledge to accept the incident, maybe miles away and then only key it again when he arrives at the scene, too late to get any kind of pre-warning?
Even expensive filters that have 80dB attenuation outside of its passband would pass a signal if a transmitter would be close enough, like a 100 meters.
Modern radios doesn't emit much stray RF. You could probably hear a local oscillator at 2 meters distance at best.
/Ubbe
1) Post rebanding, public safety is largely confined to certain frequency blocks. It is true that a lot of municipal systems do have shared service with public works and transit. If a number of receivers were networked for TDOA as in the Kiwi example, algorithms could filter out display of repeated TX uplink hits from vehicles on routes like transit or garbage trucks.
I have a bunch of 800 Mhz preselector, it would be an easy test. The only OOB trouble I can see would be low power Sprint subscribers in the adjacent bands.
2) I once solved an interference problem caused by Motorola 800 MHz Mostar Privacy Plus radios spraying 809 MHz RX LO for many blocks. Easily received line of sight. The plant argued the radios met FCC specs. I am not so sure. The product was discontinued shortly after.
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