Mobile phone companies in Australia use ordinary GSM networks, which are exactly the same as those in China, so domestic mobile phones can be used when they are brought to Australia. There are also companies in Australia that use 3G networks, which is the WCDMA standard.

The largest mobile phone company in Australia is yes optus. GSM supports 900/ 1800 frequency band, and 3G also supports it.

In other words, it is ok for domestic G-network mobile phones to go to Australia, but if you want to use Australia's 3G network, you may have to buy 3G mobile phones in Australia. Australia's 3G mobile phones can still use the domestic GSM network when they return to China.

Extended data

There are two mobile phone operators in Australia, optus and vodaphone. Optus and vodaphone have similar services, similar signal quality and similar charges. The choice depends on which isp most people know, because all plans have free time in the isp, so if you use vadaphone or telstra, using optus will obviously cost more.

Frequency bands supported by Australian mobile phone network:

2G network: mobile, Unicom GSM-850/900/1800/1900 (band 2/3/8) and telecom CDMA 1x (band 5).

3G network: Unicom WCDMA-2100 MHz/1900 MHz/850 MHz (frequency band 1/2/5/8) and mobile TD-SCDMA-1880-1920 MHz/. Telecom cdma2000-1920-1935mhz/212125mhz (frequency band BC0/BC 1).

4G network: China Unicom FDD-LTE: 1800 MHz/2600 MHz (frequency band 1/3/7).