The soon-to-be-shut down 3G network has been a critical service for 20 years, especially in regional areas, but the government wants to use the bandwidth to improve new 4G and 5G systems.

Over time, better services will be provided to people, especially in regional areas.

But in the short term, thousands of devices may stop working because they only work with 3G or need changes to their settings or hardware.

This includes some phones, watches, iPads, medical devices, cell phone boosters, agricultural equipment, and even geolocation devices in machinery, trucks, and cars.

So what can stop working from Monday?

Affected places

The people most affected by this will be those living in remote areas outside existing 3G coverage and those with what Telstra and Optus describe as “incidental” coverage.

Farmer Richard Wright is one of them.

He’s been using 3G for years, but that could change on Monday, just as he’s harvesting his crops.

“Coming to harvest is incredibly frustrating, especially when trying to coordinate trucks, headers and staff,” he said.

He spent tens of thousands of dollars to boost his cell phone signal and install irrigation sensors and soil moisture probes to run his farm.

However, since the local cell phone tower was upgraded, his equipment no longer receives a reliable 4G signal.

“Sometimes they work, sometimes they don’t, and I was told by the manufacturer that it’s all about coverage,” he said.

Telstra has committed to matching existing 3G coverage, but that’s not the case for people like Mr Wright who fall outside the coverage map.

He is turning back to shortwave radio systems to keep in touch with many of the staff on his property.

“I have two-way radios, but not everyone is around a radio.

“They all have phones in their pockets

“This is a security issue.”

education campaign

In a rare example of collaboration, Telstra and its biggest rival Optus have run a joint campaign over the past two months to prepare people for lockdown.

This is the final stage of a process that began five years ago when the federal government decided to shut down 3G.

Channa Seneviratne, who is in charge of Telstra’s technical advancement, said the company was doing its best to alert people to the change.

“In 2024 alone, we sent more than 4 million communications via email, SMS or direct mail,” he said.

Some phones will stop working

Older phones that only use 3G or phones that require changes to their settings to connect to 4/5G will stop working from Monday.

Although neither telco could provide figures on how many were still in use, Optus’s head of new products, Harvey Wright, presented some figures to a senate committee in July.

“In total, 266,000 mobile phones were at risk of disconnection (but) the figure has fallen to 176,000, representing a 34 per cent drop since May,” he said.

Arguably of greater concern were the thousands of phones Australians bought from overseas websites.

Known as “gray phones”, most of these phones will still be able to make calls when 3G is turned off, but some will not work on triple zero emergency calling.

Mr Seneviratne said phones from online retailers purchased overseas or shipped from warehouses overseas could be configured for different countries or regions, as far as Australia.

Mr Wright said there could be 25,000 Optus customers with such phones.

Mr Seneviratne said Telstra had created a tool that sent warning messages to customers whose phones might not work when 3G was turned off.

“As of last week, we had about three-quarters of a million interactions with this tool, and 35 percent of them responded, so about 250,000 people (people received a message) said, ‘You need to take action.'” he said.

Phone users can text “3” to 3498 to check if their phone needs to be upgraded to 4/5G.

Cell phone boosters are at risk

Tens of thousands of cell phone boosters used to improve signal reception in cars, RVs and homes across the country may also be affected.

Robert Landsdown, commercial manager of a rural technology business in Wagga Wagga, said around 300,000 boosters were in use.

About a third of those are older models that may need to be upgraded, he said.

“These are Cel Fi devices or Telstra Go repeaters and a lot of people have set them up for 3G and locked them to the 3G band,” he said.

Mr Landsdown said customers should check model numbers, look at the spec sheet and adjust settings.

“They need to go into the wave app on their device and update the settings to work on 4G,” he said.

“If people have been using these devices for a long time, they may have been sold with an antenna optimized to connect only to 3G frequencies.”

Check your medical devices

The National Rural Health Alliance is concerned about the hundreds of thousands of medical devices powered by 3G.

These include fall alarms, cardio monitors, oxygen systems and pacemakers.

Telcos are working with the aged care industry and companies selling medical devices, but the alliance’s chief executive, Susi Tegan, said there was still a risk of someone dying if 3G was switched off.

“Even one life has been changed or (too many) lost their lives or worse because they couldn’t change the situation or missed communication on the issue,” he said.

He said that people who have devices such as a pacemaker implanted in their bodies should consult the company that provided the device in case precautions are taken.

He worries about people with dead phones or falling devices in case of an emergency.

“If you are a family member of people who have these devices, please help them because we don’t want them to be left without a triple 0 option,” she said.

Graham Russell, chief executive of technology company Talius, which supports the aged care sector, said the sector was ready to shut down.

However, it was concerned about the unknown number of devices being purchased online from overseas, as customers were having difficulty figuring out whether they would continue to work or what action they should take.

“It will be difficult to determine how many there are as they are not actively served by anyone,” Mr. Russell said.

Free phones offered

Optus is providing 20,000 free phones to people it classifies as vulnerable.

Harvey Wright said the company hired extra staff during the change period.

He said that they will provide extra support to people who are elderly, have financial difficulties or have low technical literacy.

“In many cases, because security is our priority, we offer heavily discounted or even zero-cost phones so our customers can stay connected,” he said.

When will I notice a change?

Telstra has completed upgrades to all mobile phone base stations.

It is stated that it will take approximately a week to complete the closure, starting from October 28.

Optus still has some mobile phone towers that need to be upgraded to 4G and 5G, so they will keep 3G on in some areas and it may take a few months to shut down.