I am not local just curious on the conventional p25 FG channels. Does Philadelphia Fire use the 800 mhz conventional frequencies on all fire grounds ? What determines the difference between using the Tactical 1 or 2 ect vs a fire ground conventional channel ? My fire dept has been seeking options for fire ground communications and this looks unique and most likely works well.
If you're referring to the use of conventional channels versus trunked system talk groups, I believe that MOST of the time, PFD uses their trunked system talk groups for fireground operations. The conventional channels are used for incidents in locations where the trunked system lacks coverage, when an incident is de-esclaated but still requires on-scene communications, or when all of the tactical talk groups are being used.
If you're developing a policy for your department, the NFPA and IAFC recommend that on-scene fireground communications utilize simplex analog. This eliminates that possibility that calls will fail because a firefighter radio cannot "connect to the system" or hit the repeater, and eliminates the problem of digital voice distortion when background noise overwhelms the radio's digital vocoder.
Obviously, unless your radio system and your comm center are set up correctly, this can be challenging. A radio system has to be really well designed for a dispatcher to be able to monitor a simplex channel. Without that, that means that only on-scene units can hear the fireground traffic, which can lead to missed mayday calls, etc.
Check our Phoenix and LACo. They both have workable blends of systems/repeaters and simplex for fireground that they use everyday.
