India tests new emergency messaging system for citizens: How cell broadcast works, why it matters

It mirrors the technologies used in countries such as Japan (which issued tsunami alerts).

While tests have been on for some time now in India, this was the first time this took place on such a scale.

Here’s what cell broadcast technology is, how it works, and why it’s crucial for a country to have such an alert system.

What is Cell Broadcast technology?

Cell Broadcast is a method of simultaneously sending short messages to multiple mobile phones within a defined geographic area.

It can reach a very large number of devices at once, or, in case of hazards that affect only a small area, be sent to just a limited number of handsets, according to the International Telecommunication Union (ITU), a UN agency. The system overrides any network congestion, allowing messages to be delivered instantaneously.

It was developed in the early 1990s by the European Telecommunications Standards Institute, with inputs from telecom operators and equipment makers across Europe.

First demonstrated in 1997 in Paris, it was later adopted by several countries to simultaneously warn people within a certain area about natural disasters (tsunamis, earthquakes and lightning strikes) or human-made ones (such as gas leaks or chemical hazards).

The technology is considered an international best practice and is now used by more than 30 countries for emergency warning communications. The alerts are also adaptable to specific requirements, such as a user’s language.

How does cell broadcast work?

As part of day-to-day network functionality, cell towers communicate with phones within their reach, providing information such as the network it is connected to, according to the GSM Association, a global body that represents network operators.

This information is usually invisible to the user. Its only purpose is to help the network function as it should.

The communication of information from cell towers to handsets, and the technology that enables it, are known broadly as cell broadcast, says the industry body.

So, government authorities can harness this system of one-way communication between cell towers and phones to issue emergency alerts.

The system essentially works by sending a single message from a mobile network tower to all phones connected to that tower at the same time, instead of sending individual SMS messages.

How does it differ from an SMS?

Unlike SMS, which is a one-to-one channel, cell broadcast is a one-to-many technology. This means that one message can be sent to millions of devices within a few seconds.

CB works by distributing content through specific cell tower sites based on a subscriber’s location. Unlike SMS, CB does not require a phone number to send a message, says the GSM Association.

It therefore enables location-specific emergency alerts to be sent without the need to register or track devices.

“As well as being more private than SMS, visitors to the target area, including from abroad, will also receive alerts, and even in their own language if the system is multi-language enabled,” it says.

Also, it is much more conspicuous than an SMS.

Which countries have deployed this system?

Many countries across the world now use cell broadcast–based emergency alert systems to warn citizens about disasters and security threats.

Among the first to adopt it was Japan in 2007. Its J-Alert system transmits instant emergency information about threats such as earthquakes, tsunamis, volcanic eruptions and ballistic missiles via sirens. It was trialled in the western city of Kobe, which suffered a devastating earthquake in 1995 that killed nearly 6,500 people, according to the BCG-backed non-profit Centre for Public Impact.

Several other countries followed. The US rolled out its Wireless Emergency Alerts (WEA) system in 2012. Across Europe, countries have adopted similar systems under the EU-Alert framework, especially after an EU directive in 2018 mandated member states to implement public warning systems using cell broadcast by 2022.

In Asia, besides Japan, countries such as South Korea and Singapore have also deployed nationwide alert systems over the past decade. Other countries, including Canada, New Zealand and Chile, have introduced similar broadcast-based alerts tailored to risks like wildfires, earthquakes and floods.

What are the advantages of this system?

According to the ITU, the cell broadcast technology uses no personal data. Mobile phones can receive messages without the need for users to share phone numbers or location data.

It needs no app or subscription. The only requirement is that the phone is switched on and configured to accept such messages (Settings → Safety and emergency →Wireless emergency alerts →Test alerts).

Unlike an SMS, it is much more conspicuous thanks to its distinct alert tones and vibration cadence. This can draw people’s attention even in noisy environments.

And the accompanying pop-up message stays on the screen until the user sees it and presses the ‘OK’ button.

It will override all ongoing tasks on a mobile phone, including calls, and would be delivered even when the device is on silent or Do-Not-Disturb mode.

For this reason, this is to be used extremely sparingly, mainly when human lives are at stake. Specific triggers have been defined for sending out these alerts. And it will be delivered only to people whose lives or property is at risk due to a disaster. It will not be used to deliver a general advisory or warning. The situations that could require an alert to be sent would include major earthquakes, glacial lake outbursts, landslide, flash floods, or dam breaks.

Where does India stand?

Currently, India is using an SMS-based alert system which is operational across all 36 states and Union Territories.

According to the Indian government, the system has been extensively utilised by disaster management authorities, enabling the dissemination of over 134 billion SMS alerts in more than 19 Indian languages during natural disasters, weather warnings, and cyclonic events.

Additionally, the cell broadcast mechanism has been under development for the last few years. It is being seen as a useful tool to protect lives and property in emergency and disaster situations. While limited trials have been carried out before, this was the first major one.

The Centre for Development of Telematics (C-DOT), the Department of Telecommunications’ (DoT) research and development centre, has developed this mass broadcast technology in India.

It is not clear when the full rollout will take place.

If you receive an Alert Message on your phone, do not panic. The DoT posted on Saturday after the test: “This is part of the testing of the Emergency Alert System, so that accurate information can be received on time during disasters. During testing, this message may appear repeatedly. Ignore it; you do not need to do anything.”

Why is it important?

As climate-related disasters become more frequent and severe, technologies such as cell broadcast become extremely important for survival.

India, especially, has seen an increasing frequency of natural disasters such as flash floods, extreme temperatures and cyclones.

According to the ITU, such systems can play a large role in helping societies adapt to the impacts of climate change. It says technologies like cell broadcast are “critical elements for delivering early-warning alerts to populations at risk”.

Under the UN’s “Early Warnings for All” initiative, which ITU helps implement, cell broadcast is seen as a key tool to ensure people receive timely, accurate alerts during hazards such as floods, cyclones or heatwaves, making it an important part of climate adaptation.

The ITU says it encourages countries to consider a regulatory approach to make the use of mobile networks mandatory for public warnings.