Find out how emergency alerts work by mobile

In June 2025, the federal government inaugurated the Civil Defense Alert – a national system that sends emergency messages directly to, even if they are in silent mode. And most importantly, it does not require prior registration and works via Cell Broadcast, consolidated technology worldwide.

1. What is Cell Broadcast?

It is a message transmission system to multiple cell phones simultaneously through specific cellular antennas (cells). Unlike an individual SMS, alert via Cell Broadcast instantly reaches all devices within a geographical region – for example, whole cities – without overloading the network.

Main features:

• Shipping in seconds (up to 10 s for hundreds of thousands of cells).
• Priority alert: plays an exclusive sound and vibration, even with a cell phone in the silent
• Does not require app, registration or internet connection
• Preserve Privacy: Messages are sent by cell without tracking or identifying users.

2. Who can send and when?

In Brazil, the new system is operationalized by the Civil Defense, in partnership with Anatel and the Ministry of Communications. President Lula took a national test on June 14, involving 36 municipalities in the Northeast. The schedule foresees expansion across the country by the end of 2025.

The system is used on three main occasions:

1. Emergencies of imminent risk to life (storms, floods, landslides).
2. Alerts of great national impact.
3. Routine tests to maintain the effectiveness of the system.

3. How is the shipping process?

1. Responsible authority identifies the threat – for example, state civil defense detects a risk of flood.
2. It transmits the warning to Cell Broadcast Center (CBC), the Manager Center.
3. The CBC sends the message to the cell radios (stations).
4. The stations relay the message to all cell phones connected to that radius, up to 10 s.

In short: the citizen need not do anything. If you are in the risk area, your phone will ring and display the message. It is noteworthy that if the phone is in airplane mode, it will not receive emergency alerts via Cell Broadcast. This is because airplane mode disables all connections to the cellular network, and the alert system depends precisely on communication with the operator’s antennas (base radio stations).

4. Technological and safety benefits

• High speed and precise range: Efficient geographical coverage without affecting users outside the area.
• Emergency robustness: works even with the congested network – ideal in traffic peak situations.
• Universal Compatibility: Works in almost all modern cell phones – iOS and Android already enable by default.
• Guaranteed Privacy: Do not track or identify users.

5. Global Examples

Countries with similar systems include:

• USA: Wireless Emergency Alerts (Wea), com parcel via Fema and NWS.
• Mexico: seismic system by Cell Broadcast, running from testing in 2024
• European Union: I-Alert, with variants such as the French FR-ALERT (since 2022) and British Emergency Alert (launched in March 2023) these systems reinforce the effectiveness of this model and serve as a reference for Brazil.

6. And in Brazil, how does this system impact the citizen?

• Without action: the warning comes automatically, even with a cell phone in the silent.
• Greater collective safety: Residents in risk areas can react quickly – seek shelter, stop traffic, protect loved ones.
• Transparency in the authorities: Shipping is public, direct, traceable and periodically tested.
• Digital Inclusion: Reaches tourists and people without internet or registration – as long as they have a cell phone on.

Let us together build a future in which the protection of life and privacy are walking side by side – with ethics, intelligence and innovation. Want to deepen the subject, have any questions, comment or want to share your experience on this topic? Write for me in Instagram: .

*This text does not necessarily reflect the opinion of the young Pan.