Radio Communications and Dispatch Procedures
What you must understand
Dispatch radio work rests on a few system concepts. Simplex means transmitting and receiving on the same frequency, one party at a time; half-duplex uses two frequencies so a unit can hear while not transmitting; a repeater receives a weak portable signal and rebroadcasts it at higher power. Trunking pools channels and assigns them per transmission, and talkgroups let agencies share or separate traffic. P25 is the digital interoperability standard that lets different manufacturers' systems talk to one another.
Protocol and discipline
Transmissions follow a pattern: identify who you are calling, identify yourself, then state the message. Keep them short, speak across the microphone rather than into it, and listen before keying up so you do not step on another unit. Readability and signal-strength reports tell you whether the message actually arrived; if it did not, repeat it. Plain language is the NIMS expectation - codes differ between agencies and between regions, so "10-4" and "10-50" can mean different things down the road.
Traps candidates fall for
- Assuming every agency in a mutual-aid response shares your 10-codes.
- Broadcasting sensitive information, such as a patient's name or a juvenile's identity, over an open channel.
- Escalating traffic without the accepted prowords: "emergency traffic," "priority traffic," or "Mayday" clears the channel for life safety.
- Failing to repeat back addresses, unit numbers, and times, or to confirm acknowledgement.
- Long, conversational transmissions that block the channel during a critical incident.
- Promising a unit "they're almost there" when you have no arrival information.
Rule of thumb
Acknowledge, clarify, confirm. Repeat back any address, unit identifier, or time-critical instruction, and remember that the telecommunicator should be the party talking less.
Worked example
Unit 12 keys up: "Dispatch, Unit 12, emergency traffic." You immediately clear the channel - "All units hold traffic, Unit 12 emergency traffic" - and only then take the message. Announcing the emergency status protects the unit; skipping it leaves other units transmitting over an officer in trouble.