By now you know how a single repeater extends a conventional channel, and Part 2 walked through how P25 stitches many sites together into one simulcast system. This time we look at trunking itself: the idea that a small pool of channels can serve many more talkgroups than there are [...]
When the internet drops, the cell towers overload, and even your regional trunked system loses its backhaul, there is a class of communication that keeps working because it was never dependent on any of that infrastructure in the first place. High frequency radio, run by licensed amateur volunteers [...]
There is a category of communications infrastructure that sits quietly in most regions, built and maintained entirely by volunteers, that can pass a voice signal across hundreds of miles from a handheld radio the size of a candy bar. Linked amateur radio networks tie many repeaters together so that [...]
Most public safety radio traffic today rides on VHF high band, UHF, 700, or 800 MHz trunked systems, so it is easy to forget that a much older stretch of spectrum is still in service under a few specific circumstances. VHF low band, the range roughly from 30 to 50 [...]
If your jurisdiction touches a big lake, you already know the water changes the job. What many land-based departments do not fully absorb until they are twenty minutes offshore in a building sea is that the radio changes too. The portable that works fine at a structure fire is not [...]
If your jurisdiction has a dam, a lock, a reservoir, or a stretch of navigable water inside your response area, you already share that geography with federal partners who may show up on your worst day. The hard part is not that they exist. The hard part is that you [...]
Radio encryption is one of those procurement decisions that looks like a checkbox on a spec sheet and turns out to be a fork in the road. Pick the wrong option and you can lock casual listeners out while leaving a determined one in, break mutual aid the first time [...]
Every responder keys a radio without thinking much about what happens between pressing the button and being heard. But underneath that simple act sit two very different designs for how radio traffic gets carried, and the one your department uses shapes your coverage, your capacity during a bad day, [...]
It happens on a mutual aid scene at least a few times every year somewhere: two radios are set to the exact same frequency, everyone is keying up, and nobody can hear anybody. The frequency is right. The power is on. The antennas are fine. And yet the two crews [...]
The first time someone hands you a portable radio and tells you to "go to the fireground channel," it can feel like being asked to fly a plane you have never seen. Buttons, a knob or two, a little screen full of shorthand, and a room full of people who [...]
