LTE – or 4G, as it is more commonly known – is crucial when it comes to reliable PTT (or PoC) communications. Before the rollout of 4G, PTT communications were often unreliable, broken, and even delayed or completely lost.


When it comes to specialised PTT devices, there are a number of choices. Many of the less experienced providers offer 3G-only devices. Make sure when you choose a device it uses the 4G network (and supports all Australian frequencies including Band 28), and here are some reasons why.


(1) 3G networks are rapidly approaching end-of-life

(2) 4G rarely suffers from congestion like 3G does

(3) 4G works with low signal strength when 3G becomes unreliable

(4) 4G gives better performance than 3G


How to spot a 3G-only device:

  • Your provider can’t (or won’t) tell you if it’s 4G capable
  • It is marked “band 5”, “B5”, “850MHz”, “WCDMA” or 3G.


(1) 3G networks are approaching end-of-life


Telcos are already talking about the shutdown of their 3G networks. Telstra has announced their 3G network will be switched off in 2024. 3G frequencies are already being re-farmed for 4G use, which means capacity on 3G networks is reducing (making congestion more of a problem).


Why invest in obsolete equipment ?


(2) 4G rarely suffers from congestion like 3G does


At incidents and major events, 3G networks become congested and data transfer becomes unreliable and sometimes stops. Because PTT exclusively uses mobile data, this results in unreliable PTT communications, or no PTT communications at all.


4G networks rarely suffer from congestion. As well as basing this on technical data and customer feedback, we regularly perform trials on Telstra 4G at busy times and major events including shopping centres on boxing day; events such as NYE, the Easter Show and other busy periods. At these times we do a comparison with a device running on 3G only. The 3G device usually locks up completely, and occasionally might get through for a broken conversation. This also occurs during every-day events such as traffic incidents and peak hour.


(3) 4G works with low signal strength when 3G becomes unreliable


On 3G networks, when signal strengths drop, the data connection on 3G becomes unreliable, even when phone calls and SMS are still OK. Since PTT uses data, this is a problem for 3G-only PTT devices, and effectively reduces the coverage area.


It is crucial that you have a device which includes 4G Band 28. Band 28 is the lower (700MHz) frequency used by Telstra and Optus for extended rural and regional 4G coverage. Without Band 28 you will often default back to 3G when out of metro areas (and as higher frequencies are re-farmed for 5G, as we are seeing right now with 3G). When 3G disappears, there will be nothing to fall back to.


4G networks are designed for data from the ground up. The data connection is reliable right to the edge of the coverage area on a 4G network. This results in much better reliability and performance across the entire coverage area.


(4) 4G gives better performance than 3G


4G gives lower latency, which means faster key-up times, negligible delay, and better communications. Along with the other advantages above, this makes 4G an absolute necessity when choosing a device for your PTT or PoC communications.


See also:

IMPULSE Wireless live testing gives positive results with Telstra Mobile

Reliable two-way communications for retail and shopping centres