Dc fire/ems station notifications

I am not seeing any vhf or uhf frequencies listed for dc fire/ems to dispatch simulcast out tones to notify stations on. So that leads me to believe that they are using an ip based system for every station to notify them of calls. Is that right? Can somebody confirm that? If so, how does that work?


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BlueMoon2 said:

I am not seeing any vhf or uhf frequencies listed for dc fire/ems to dispatch simulcast out tones to notify stations on. So that leads me to believe that they are using an ip based system for every station to notify them of calls. Is that right? Can somebody confirm that? If so, how does that work?


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Many all-career departments using trunked radio systems use digital station control and alerting that is silent to the user. It uses a digital stream on a dedicated talk group, or, in 96bps systems, can actually use the TRS's control channel. It's called SCADA (or MOSCAD on a Motorola system), and it allows many benefits over traditional two-tone paging. It is bidirectional (confirmations of alarms, and frequent silent confirmations that the station and the dispatch system are connected. It can also handle numerous pieces of data, such as for multiple units stationed, garage doors, lighting circuits, traffic signals, stove disconnects, etc.

In Baltimore City, our station alerting is performed via the TRS control channel, with IP/internet fallback.

The only downside is that scanner enthusiast can't easily decode these signals to hear calls for select stations.

DC Fire/EMS Notification

Thanks Matt, for clearing that up. Our system (Charlottesville/Albemarle/UVA) is a combination department so we don't have that. I always wondered how that worked!

DC uses IP primarily.

http://purvispublicsafety.com/wp-content/uploads/2014/01/PURVIS-dc-case-study-final.pdf

FSAs

Thanks Rescue,

That's pretty cool! Now I'm just wondering, DCFD is out doing pubed, etc, how are they notified of an incident? I'm guessing over the radio and maybe a text to the truck? I'm curious as to if there radio system is Motorola, Harris, Kenwood, etc.

Charlottesville will be upgrading its radio system in the not too distant future (right now they're still dealing with the new CAD system from New World). I know that right now Charlottesville has Motorola APX 4500 mobiles and APX portables. I'm wondering if that means that the new system will be Phase 1 or Phase 2 FDMA or TDMA. I would imagine Phase 2 TDMA, but I don't know.

Any insight?

Units on the air are alerted over the dispatch talkgroup and their MDTs.

DC's system is Motorola-constructed. You can easily tell this by the fact that there are only four channels that are control-channel-capable (red/blue in the RRDB), and they are dedicated to this function. Harris systems have a more... robust architecture that can use any base radio as a control channel transmitter, so you'll see them all marked red/blue in the RRDB.

RE Charlottesville... all new systems being shipped by Motorola are TDMA and Dynamic Dual Mode (TDMA talkgroups revert to FDMA when an FDMA-only radio affiliates) capable. With APX radios being fielded and the XTS series going out, they will likely use at least some TDMA talkgroups, but deployment of TDMA talkgroups as/when/where needed is up to the city and the system engineers.