How Push-to-Talk over Cellular Works —
and why it beats UHF for most Australian fleets
Everything you need to know about PTToC in plain English — how it works, how it compares, and what to look for in a provider.
What is push-to-talk — and what’s the difference between PTT and PTToC?
Push-to-talk (PTT) describes any communication system where you press a button and speak instantly to one person or a group — without dialling a number, waiting for someone to answer, or taking turns on a phone call. Traditional two-way radios have worked this way for decades.
The limitation of traditional PTT — UHF, VHF, analogue, DMR — is range. Your radio can only transmit so far. If you want to cover a large area, you need repeaters: expensive towers strategically placed to relay signals. More routes, more repeaters. More geography, more maintenance. More problems.
PTToC — push-to-talk over cellular — solves the range problem completely. Instead of using its own radio frequency, a PTToC device transmits your voice over the 4G/5G mobile data network, through a dedicated PTT server, and out to every device in your group — instantly. The same button. The same speed. But the range of Australia’s entire mobile network.
For most fleets, this is the difference between a system that works on your depot yard and a system that works on every route your drivers run — regardless of where those routes go.
Push-to-talk (PTT)
Press a button. Talk instantly to one person or a group. No dialling, no ringing, no waiting. Works on two-way radio frequencies — limited by range and infrastructure.
Push-to-talk over cellular (PTToC)
Same button. Same instant communication. But instead of radio frequencies, your voice travels over 4G/5G — giving you the same coverage as the mobile network, nationwide.
Also written: PoC, PoC radio, PTT over LTE, push-to-talk over LTE.
What actually happens when you press the button
No jargon. This is what happens technically from the moment your driver’s thumb hits the PTT button.
Button pressed — voice captured
The driver presses the dedicated PTT button on their radio. The device immediately captures voice audio and compresses it into a small data packet. Dedicated PTToC hardware is designed to do this faster and more reliably than a smartphone running a general-purpose app.
Data sent over 4G/5G
The compressed audio packet is transmitted over the mobile data network — the same 4G or 5G network your phone uses. The device needs a SIM card and a data connection, nothing else. No radio frequency, no line-of-sight, no repeater infrastructure.
Routed through the PTToC server
The data packet reaches a dedicated PTToC server — in Press2TALK’s case, Australian-owned server hardware physically located in Australia. This server manages call routing: it knows which group the device belongs to, who should receive the transmission, and delivers it accordingly. For any PTToC provider, ask exactly where this server lives and who owns it. Not who owns the VM, who owns the server hardware.
Delivered instantly to the whole group
Within a fraction of a second, every device in the talk group receives the audio. Whether those devices are 5 kilometres away or 500, the connection time is the same — because cellular coverage doesn’t decay with distance the way radio frequency does.
Dispatcher receives it too
Any web-based dispatcher console connected to the same network receives the transmission in real time — along with the sending device’s GPS location, which is also updated continuously. The depot can hear every transmission, respond to any radio, and see where every vehicle is, all from a browser.
48+ consecutive months
connect time
stored in Australia
retention