Taiwan tests emergency communication backups amid simulated internet blackout drills

In Taipei, the streets swiftly empty as air raid sirens ring out and alerts ping on mobile phones. Police officers usher any stragglers into shelters, leaving the capital suddenly deserted.

In cities across Taiwan, these kinds of drills are a fact of life every year, amid the growing threat posed by China across the strait, but this time there is something different.

Internet speeds were drastically cut on Thursday, simulating a coordinated attack for the first time. Data-heavy services such as video calls, streaming and mobile payments became difficult or impossible to use, while videos on social media barely loaded.

However, Wang Chen-wen knows how to reach others.

When the sirens sound and her mobile internet begins to grind to a halt, Wang goes to the roof of her 25-storey apartment building, searching for a better radio signal. She connects her phone via Bluetooth to a small, flat device hanging from her bag. Within seconds, she is sending messages without relying on the internet. Minutes later, some of them succeeded in reaching a friend in a neighbouring district.

“Testing from Beitou district, Taipei.” “Xinyi district, Taipei.” Messages begin coming in as users share their locations in a group chat being tested on an open-source platform that allows people to use text messages via long-range, low-power radio signals.

“You can’t wait until something actually happens to realise you should have prepared,” says Wang, who leads a local group that provides civil defence training and started learning how to use the platform about six months ago.

Authorities said the drill was designed to encourage people to prepare alternative means of communication in an emergency – part of Taiwan’s efforts to strengthen its civil resilience in the face of growing military threats from Beijing, which claims the self-ruling democracy as its own territory and has not ruled out using force to annex it.

The internet disruption exercise took place on two separate days this week across 14 cities and counties in northern and central Taiwan, home to roughly 70% of the island’s 23 million people.

“If the idea is to recreate what it might be like during a war, it’s definitely inconvenient, but I can understand why they’re doing it,” says Jimmy Chu, a 22-year-old worker who says messages from his boss failed to come through during the drill.

Tzeng Yi-suo, an associate researcher at Taiwan’s Institute for National Defense and Security Research, says the inconvenience itself was intentional.

“It’s a starting point for raising public awareness,” Tzeng says. “Through repeated exercises, people will gradually understand that this is about experiencing that inconvenience and testing the backup systems we may need.”

For Chen Hui-xuan, an 18-year-old who tried to use her phone on the metro during the drill, the inconvenience was real. “TikTok wouldn’t open at all. Facebook worked, but it was really slow, and messages on Instagram took around 30 seconds to send,” she says.

There is growing concern about the vulnerability of Taiwan’s submarine cable network – 16 international cables and 10 domestic ones – which the government has called an “irreplaceable digital lifeline”.

Several cables have been damaged in recent years in incidents involving Chinese or China-linked vessels, which Taiwan’s coast guard has described as a “grey zone” strategy aimed at depleting the island’s resources without crossing the threshold into an act of war.

In 2025, a Chinese captain was convicted of deliberately damaging a cable linking Taiwan’s main island with the offshore Penghu archipelago, while another Chinese fishing boat captain was later convicted of negligently damaging a cable serving Matsu, another outlying archipelago administered by Taiwan.

Taiwan is seeking to build multiple layers of backup communications so that no single disruption can cut off the island. The options include low-Earth-orbit satellite services that could help people stay connected should terrestrial networks be disrupted.

The approach has drawn on lessons learned in Ukraine, where Elon Musk’s Starlink has played a role after conventional infrastructure was damaged during Russia’s invasion. Last month, Taiwan’s legislature approved amendments that could clear the way for Starlink to enter the local market, although relying on Musk’s network has raised concerns because of his extensive business interests in China.

In a crisis where internet access was limited, Tzeng says people would face “a high degree of uncertainty and fear”, which hostile forces could exploit. “The question is how you use the backup communications channels available to get reliable information to people and reassure them.”

For Wang, knowing she has another way to communicate has already made a difference. “At least I know that if something happens, I already have a basic plan and know what to do, so I won’t face whatever disaster may come with fear or panic,” she says.