What is a PTT talk group?
A PTT talk group is a set of radios and consoles that hear each other when anyone in the group presses the push-to-talk button. A guard talks to the group, not to one phone number.
The talk group plan decides who hears what. Too few groups and guards drown in traffic that is not theirs. Too many and the control room cannot keep track. With GSM PTT radios and talk groups managed from the cloud, the plan can change without reprogramming each radio by hand. If you are still choosing between PoC and two-way radio, read our PoC vs two-way radio guide first.
Which terms should you know before planning talk groups?
The 3GPP standard for mission-critical push-to-talk, TS 22.179, defines the terms most PTT systems use. It is written for emergency services, but its definitions are a useful checklist for any control room.
- Group member and affiliation. A member is authorised to use a group. An affiliated member has also shown interest and is ready to send and receive on it.
- Dispatcher. A user who joins calls for command and control.
- Floor control. The system that decides who may talk at a given moment. Only one person holds the floor.
- Private call. A call between two users, outside the group.
- Broadcast group call. A one-way call where no reply is expected, such as an all-call announcement.
- Group regroup. Temporarily combining several groups into one, for example during a major incident.
Commercial PoC services do not necessarily implement this standard in full. Ask your supplier which of these functions its radios and dispatcher support.
How should a security company organise its talk groups?
Build groups around sites and roles, not around individual people. People change; sites and roles stay. The table shows a pattern that suits most guarding companies.
| Talk group | Who is in it | What it is for |
|---|---|---|
| Site group (one per site or cluster) | Guards on that site, the area supervisor, the control room | Routine traffic: patrol reports, gate queries, handovers |
| Supervisors | Area supervisors, the shift commander, the control room | Staffing, late guards, escalations, site visits |
| Response | Response vehicles and the control room | Dispatch to alarms and incidents, arrival and clear reports |
| Emergency | The control room, supervisors and response, monitored at all times | SOS calls and incidents where someone is in danger |
| All-call (control room only) | Every radio | Short announcements to everyone, such as a weather warning or a road closure |
Should groups follow shifts? Usually not. A shift change swaps who carries the radio, not who needs to hear whom. Hand the radio over with the post and keep the group the same.
Illustrative example: a company guards 12 sites in two suburbs, with two response vehicles and three supervisors. It runs 6 site groups (nearby sites share one), a supervisor group, a response group, an emergency group and an all-call. That is 10 groups, and each guard normally listens to one.
Where does the control room fit in the talk group plan?
The control room should be able to hear and reach every group. Guards should normally hear only their own.
- One console for every group. A browser-based dispatcher lets a controller talk to one guard, a group or everyone. A desktop base station, such as Zamatrack's TM7, adds a fixed radio.
- A named controller per shift. Someone must own the emergency group at every moment, including during breaks and handovers.
- A fallback. Decide how controllers reach guards if the control room loses power or its internet link, for example from a radio or phone on mobile data.
- A handover log. At shift change, the outgoing controller lists open calls and emergencies for the incoming one.
How should the control room dispatch over PTT?
By the same steps every time, so any controller can pick up where another left off. A written procedure also makes recordings easier to review.
- Receive and acknowledge. Answer every call with the caller's call sign, so the caller knows they were heard.
- Get the essentials. Who, where, what happened and whether anyone is hurt. Repeat them back.
- Check the map. Find the nearest supervisor or response vehicle on the live map before you choose who to send.
- Dispatch on the right group. Send response on the response group, not on the site group where guards are working.
- Log the time. Record the call, the dispatch, the arrival and the all-clear, with times.
- Close the call. Confirm the outcome with the site and tell the caller the matter is closed.
Keep the control room's own traffic short. A controller who talks for a minute holds the floor for a minute, and nobody else on that group can call in.
How should SOS and emergency calls be handled?
An SOS alert must reach a person who owns it within seconds, and stay open until that person closes it. The rest is procedure.
TS 22.179 describes the model well. An emergency alert carries the user's identity and their most current location. The user stays in an emergency state until it is cancelled. If a dedicated emergency group is used, users who support emergencies must monitor it. The standard also separates an emergency call, where the caller is in danger, from an imminent peril call, where the caller reports danger to someone else.
Turn that model into a written procedure for the control room:
- See it. The SOS alert should show the guard's identity and last known location on the dispatcher screen.
- Acknowledge it. One named controller takes ownership, so two people do not each assume the other is dealing with it.
- Clear the channel. Tell the group to stop routine traffic until further notice.
- Reach the guard. Call the guard directly. If there is no answer, treat it as real.
- Send help. Dispatch the nearest response and supervisor, and call emergency services where the procedure says to.
- Close it formally. Only the controller who owns the emergency closes it, after the guard is found and safe, and logs why.
Test the SOS button on every radio on a fixed schedule, with the control room warned first. A button nobody has pressed is a button nobody knows works. For the wider supervision picture, see how to manage security guards effectively.
What call discipline should guards follow?
Short, clear calls that leave the channel free for the next person. These rules work on any push-to-talk system.
- Listen before you talk. Do not talk over a call that is in progress.
- Identify yourself. Start with who you are calling and who you are, using call signs.
- Think, then press. Know what you will say before you press the button, and keep it short.
- One message at a time. Only one person can talk at once, so long messages block everyone else.
- Confirm instructions. Repeat back locations, names and number plates.
- Plain language. Avoid codes that new guards or relief staff may not know.
- No personal chatter. Groups are for work. Calls may be recorded.
- Never ignore an emergency. Stop routine traffic when an emergency is declared.
Put the rules in the site instructions and train new guards on them on day one. Use the recordings to coach, not only to investigate.
How do you test and maintain a talk group plan?
Review it whenever a contract starts or ends, and check it on the ground before you rely on it.
- Test coverage at every post. PoC needs mobile data. Check basements, plant rooms and the far corners of each perimeter before go-live.
- Keep a group register. List each group, its members and its purpose. Remove radios that have left a site.
- Test the emergency path. Run a planned SOS test and time how long the control room takes to acknowledge it.
- Listen back. Review a sample of recorded calls each month for discipline and response times.
How Zamatrack handles talk groups and dispatch
Zamatrack supplies GSM push-to-talk (PoC) radios, the T700L and the T710A, that carry voice over mobile data anywhere with coverage across South Africa.
- Group talk can span several sites. Radios are programmed and updated through the cloud.
- Radios link with smartphones, vehicle radios and dispatcher PCs, and show live GPS locations.
- The PTT Dispatcher Platform runs in a web browser. The control room sees every radio on a live map with its route history, and talks to one guard, a group or everyone.
- The dispatcher receives SOS alerts and geofence alerts, and keeps voice recordings for investigations.
- A built-in patrol mode lets guards scan NFC tags with the radio for basic rounds, with an audible confirmation and Excel reports.
- Without mobile data coverage, a PoC radio has no voice until coverage returns.
Prices exclude VAT. The PTT Comms Radio Bundle is R140 per month and the PTT Patrol Radio Bundle is R230 per month, radio not included. A T700L rents for R295 per month over 24 months, and the PTT Dispatcher Platform is R300 per month.
Frequently asked questions
What is a PTT talk group?
A PTT talk group is a defined set of radios, phones and dispatcher consoles that hear each other when anyone in the group presses the push-to-talk button. Security companies usually build talk groups around sites and roles, so guards hear the traffic that concerns them and the control room can reach any group.
How many talk groups does a security company need?
As few as will keep traffic relevant. A common pattern is one group per site or cluster of nearby sites, plus groups for supervisors and response vehicles, and an all-call from the control room. If guards ignore their radios because most traffic is not for them, split the group.
Should talk groups be set up per shift?
Usually not. Shifts change who carries the radio, not who needs to hear whom. Keep groups per site or role, and hand the radio over at shift change. A separate group for a shift only makes sense when two shifts overlap on the same site and must not interrupt each other.
What should happen when a guard presses SOS?
The control room should see the alert, the guard's identity and last location at once, acknowledge it, try to reach the guard, and dispatch help by a written procedure. The emergency stays open until a named controller closes it, and every step is logged with the time.
Do PoC talk groups work without mobile signal?
No. A PoC radio carries voice over mobile data, so a guard without data coverage cannot talk or be heard. Test coverage at every post, including basements and far corners of the perimeter, before you rely on PoC there, and plan another way to reach guards where there is none.
Sources
- ETSI TS 122 179 V19.3.0 (3GPP TS 22.179 Release 19): Mission Critical Push to Talk, Stage 1. ETSI and 3GPP. Clause 3.1 (definitions: affiliation, dispatcher, floor control, private call, broadcast group call, group regroup) and clause 5.7.1 (emergency alerts, emergency state, emergency groups, imminent peril).