3G network shutdown - Telstra, page-3

PAGE 12.
M2M Connectivity estimates that there are more than 1m devices/units in total that will be affected nationally.

Only changing the SIM will not work as the device will need the 3G chipset replaced with a 4G chipset in order to work.

According to NBN data, it is estimated there are 286,000 IoT monitoring devices that will require replacement over the three-year time frame from now. These devices include alarms, safety pendants and alert systems.

The cost for replacement is expected to be approximately $96m and is likely to be funded through corporates, such as Telstra, in a similar way to how the transition will occur for the mobile phone market.

https://www.hsctg.com.au/wp-content/uploads/2021/06/MST-Access-HSC-Initiation-Report-11Jun21-1.pdf