Optus is planning to reallocate 2100 MHz spectrum currently used for 3G services to its 4G and 5G networks in April next year.
It means the telco will no longer offer a dual-band 3G network after April 2022, with 3G services to be offered through its 900 MHz spectrum only.
Optus said some of the 2100 MHz assets would be reallocated as part of a network technology refresh to provide better 4G network coverage and support the growth of 5G.
It has urged customers with a 2100 MHz-only 3G device to upgrade to a 4G or 5G capable device to continue to access its network.
Optus Wholesale service provider customers using the 2100 MHz network will also be affected, the telco said.
Telstra switched off its 2100 MHz spectrum in March 2019, while Vodafone has phased 3G connectivity on its 2100 MHz spectrum.
Optus networks managing director Lambo Kanagaratnam said the planned refresh comes as customers increasingly adopt 5G devices.
“In the last 12 months we have really seen our customers embrace 5G technology with take up of 5G enabled devices growing significantly,” he said in a statement.
Kanagaratnam said that with data usage continuing to increase, the reallocation would ensure “spectrum assets are working well for customers”.
“We know that our customers are using more data than ever. They’re downloading, sharing and streaming content, using apps and connecting with friends and colleagues virtually,” he said.
“In order to support this thirst for connectivity it’s vital that we evolve our network and redeploying our 2100MHz spectrum assets to better accommodate next generation technologies is an important step in achieving this.”
Optus is planning to contact customers impacted by the planned shutdown of its 3G network on the 2100 MHz spectrum over the coming months.
“Importantly we are providing 12 months’ notice to ensure affected customers are aware of our plans and have sufficient time to upgrade to newer devices that can support 4G or 5G,” Kanagaratnam added.