The 3G coverage is expected to be restored on Thursday, May 26, while 4G is expected to be back by the morning of Friday, May 27.
New 5G coverage is expected to be available within days of the upgrade works being completed.
Landline services, NBN internet services and mobiles not using the Telstra network will not be impacted.
Any 000 calls while the site is not working will divert automatically to any working mobile network.
Telstra regional general manager Steve Tinker said mobile base stations in Barooga, Tocumwal and Strathmerton could help provide coverage on Cobram’s outskirts, but most of the impact would be in the town itself.
“There’s never a good time to undertake this sort of work but, once its completed, it will mean better mobile services for local residents,” he said, adding they would try to just switch off parts of the tower they would be working on.
“While coverage and capacity will decline during this time, we want to keep total blackouts to an absolute minimum,” he said.
Residents can avoid disruptions by activating wifi calling on their mobiles, which will them to use the internet to make and receive calls.
Retailers can connect their EFTPOS systems to landline or wifi and NBN internet connections instead of the Telstra network to avoid connectivity disruptions. They must have an EFTPOS machine that can switch between connectivity.
The new Telstra 5G network is expected to provide more capacity and network connectivity, while reducing network congestion in Cobram’s mobile networks. Users will need a 5G-capable device and a Telstra 5G plan.
It will join more than 350 cities and towns, or 77.5 per cent of Australians, connected to the 5G network nationally.