The Australian government said it's creating a working group, made up of Telstra, Optus, TPG, and the Australian Mobile Telecommunications Association (AMTA), to manage the 3G to 4G switchover "in a safer way."

The announcement of the working group comes after it was revealed an estimated 740,000 Australians with 4G handsets could be impacted by the shutdown of 3G.

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In a statement, the government said on Sunday (March 17), that the Working Group will focus on a subset of 4G handsets configured by the manufacturer to use 3G for calling 000 (aka Triple Zero, Australia's main emergency service number), despite otherwise working over 4G to make voice calls.

First announced in 2019, the 3G network switchover will provide a more efficient use of spectrum by mobile network operators to boost capacity and data speeds.

“The government is concerned customers in possession of particular 4G handsets may mistakenly believe their mobile device is unaffected post-switchover, as the handset could continue to operate normally for voice and data, except when trying to call Triple Zero,” Communications Minister Michelle Rowland said in a statement.

"The Government strongly advises consumers against placing test calls to Triple Zero, given impacted devices will still work over existing 3G services until the 3G switchovers occur later this year. This will not provide an answer on whether your phone is affected, and could prevent others from accessing life-saving support."

The formation of the working group could, however, delay the shutdown of Optus' and Telstra's 3G networks.

Telstra is planning to retire its 3G network on June 30, while Optus is due to call time on its 3G network in September. Vodafone Australia, which is a subsidiary of TPG Telecom, closed its 3G network at the end of January.