Cell Broadcast Service on Xiaomi: a hidden feature you didn’t know about

If you’ve ever looked into the list of system applications on your Xiaomi, you’ve probably noticed the mysterious Cell Broadcast Service. It doesn't have a desktop shortcut, it doesn't show up in the app menu, but it does appear regularly on the active process list, and it can even consume battery power. What is this program? Why is it installed on your Redmi, POCO Or Mi without your knowledge? And most importantly, can it be removed without the consequences for the phone?

Many users mistakenly mistake Cell Broadcast for a virus or spyware, especially when they see it on the permission list with access to the Internet. SMS It's actually a standard Android component that handles emergency alerts from carriers, but Xiaomi's implementation has its own features, from the non-standard name of the package to hidden settings that are not documented in official manuals.

Today we’ll take a look at how the service works on Xiaomi devices, why it’s needed in 2026, and what happens if it’s turned off or removed, and why some users complain that Cell Broadcast Service wakes up in the middle of the night and drains its battery.

What is Cell Broadcast Service and Why You Need It?

Cell Broadcast (CB) — It's a mass text alert technology that mobile operators use to send out emergency messages. SMS, These notifications are sent to all subscribers in a particular coverage area, regardless of their employment or phone status, a technology that has been around since the 1990s, but has only become widespread in recent decades.

On Xiaomi smartphones, the Cell Broadcast Service system application (in some firmware applications, it may be called com.android.cellbroadcastreceiver or com.miui.cellbroadcast) is responsible for processing such messages.

• 📢 Receiving emergency alerts from the Ministry of Emergency Situations, the government or the operator (for example, about natural disasters, terrorist attacks, man-made disasters).
• 🌍 Support for geolocation notifications – messages are only sent to users who are at risk.
• 🔊 Replaying the alarm sound even if the phone is silent.
• 📱 Display push notifications on the high priority lock screen.

In most countries (including Russia, the European Union, the United States, and Asia), operators are required to support the technology by law, for example, in the EU since 2018, the EU-Alert directive has been in place, requiring telecom providers to send emergency warnings. In Russia, similar requirements are prescribed in the order of the Ministry of Communications № 482 from 2014.

However, in practice, many Xiaomi users have never received such alerts, because:

1. The technology is not always used by operators (especially in the regions).
2. Some firmware MIUI have bugs that prevent messages from reaching the user.
3. In default settings, certain types of notifications may be disabled.

How Cell Broadcast works on Xiaomi: technical details

Unlike the usual ones. SMS, And when you send them to a specific number, the Cell Broadcast is broadcast over a special channel on the mobile network. ETWS (Earthquake and Tsunami Warning System CMAS (Commercial Mobile Alert System) and transmitted through the operator's base stations:

• 📡 No Internet connection is required – a mobile network is sufficient (even if you have a mobile network). 2G).
• 📱 The message arrives on all devices in the coverage area, regardless of model or firmware.
• 🔋 No traffic is consumed or SMS-balance (notifications are free for the subscriber).

On Xiaomi smartphones, the processing of such messages takes place in several stages:

1. The operator’s base station sends a data packet with an alert.
2. A phone modem (such as Qualcomm Snapdragon or MediaTek Helio) receives the signal and transmits it to the com.android.cellbroadcastreceiver system application.
3. Cell Broadcast Service decodes the message and determines its type (tsunami, hurricane, man-made accident, etc.).
4. If the message matches the user's settings, it is displayed on the screen with an audible signal.

It is important to understand that this is not a regular application, but a system component integrated into the firmware. MIUI. It works on the Android system level and has extended rights, including:

• ⚡ Access to the mobile network without requesting permission.
• 🔔 Ability to play sounds even in silent mode.
• 📱 Show notifications over all windows (including full screen games).
• 🔄 Automatic start-up when booting the system.

These are the permissions that users often suspect, but they are necessary for the service to work properly, because the emergency alert must reach you in any case, even if the phone is dead or in Do Not Disturb mode.

💡

If you want to check whether Cell Broadcast works on your Xiaomi, you can use the test service of some carriers, for example, MTS and Beeline periodically send out trial notifications as part of the system check.

Why Cell Broadcast Service is draining the battery and how to fix it

One of the most common complaints of Xiaomi users is that Cell Broadcast Service appears in the list of active processes and consumes battery power. 5-10% The cost of the day is particularly noticeable on budget models like Redmi. 9A or POCO M3.

The reasons for this behaviour are:

To diagnose the problem, follow the following steps:

Check the "Battery" section in the settings → Find Cell Broadcast in the Energy List|

Open the Settings. → Annexes → Application management → Cell Broadcast Service → Check out the usage statistics|

Install the BetterBatteryStats app (root required) for detailed awakening analysis|

Try to temporarily disconnect. SIM-Map and observe the behavior of the service-->

If the problem is confirmed, there are several ways to solve it:

1. Disabling unnecessary notification channels (see the next section).
2. Limit background activity through battery settings (but this can block important notifications!).
3. Update of the firmware - in new versions MIUI 14/15 Optimized energy consumption of system services.
4. Resetting network settings (Settings) → SIM-maps and mobile networks → Resetting network settings).

⚠️ Note: If you notice that Cell Broadcast Service consumes more than 15% of its charge per day or is actively using mobile traffic (more than 10 MB / day), this may be a sign of a virus. → The phone. → Reset settings) or flash the device through the Mi Flash Tool.

How to Configure or Disable Cell Broadcast on Xiaomi

By default, setting up emergency alerts is hidden in the depths of the menu MIUI. To get to them, follow the following steps:

1. Open the Settings.
2. Go to the Appendix section.
3. Select Application Management.
4. In the search bar, type Cell Broadcast and select the appropriate app.
5. Press Notifications.

Here you will see a list of the types of alerts your carrier can send, depending on the country and firmware, they may include:

• 🚨 Emergency warnings (fires, floods, earthquakes).
• ⚠️ Warnings about man-made accidents (gas leakage, accidents at nuclear power plants).
• 🚓 Reports from law enforcement agencies (search for criminals, terrorist threat).
• 📢 Test mailings (checking the system by the operator).
• 💰 Advertising (in some countries operators use the CB marketing).

You can disable unnecessary categories by moving the sliders to the off position. However, keep in mind:

• Disabling emergency alerts can be dangerous to life in at-risk areas.
• Some operators (e.g. MegaFon) link important notifications to test channels.
• In EU countries, disabling emergency alerts may be prohibited at the firmware level.

If you want to disable Cell Broadcast Service completely, you have two options:

1. Through ADB (rootless: adb shell pm disable-user --user 0 com.android.cellbroadcastreceiver Note: After a reboot, the service may be activated again.
2. Removal of the system APK (root and magisk required: su rm /system/priv-app/CellBroadcastReceiver/CellBroadcastReceiver.apk Warning: This may disrupt other system components!

⚠️ Note: Some Xiaomi models (e.g. Mi 11 Ultra or Redmi Note 12 Pro)+) Disabling Cell Broadcast Service can cause a communication module to malfunction, if your mobile Internet is lost or you stop coming after deactivation. SMS, Return the settings to the original state by the command: adb shell pm enable com.android.cellbroadcastreceiver

Cell Broadcast vs. Regular SMS: What's the difference and what's more reliable

Many users confuse Cell Broadcast with the usual SMS-But there are fundamental differences between these technologies:

The main advantage of Cell Broadcast is guaranteed delivery in emergency situations, for example, during the earthquake in Turkey in 2023, the usual delivery is not possible. SMS Mobile Internet stopped working due to network congestion, but emergency alerts CB reached out to subscribers.

However, the technology has disadvantages:

• ❌ Limited length of message (usually up to) 1395 Symbols, but operators often use only 80-90).
• ❌ There is no confirmation of delivery (you will not know if the message will be received by the addressee).
• ❌ Not all phones handle messages correctly (especially older Android 8 and lower models).

On Xiaomi smartphones, the implementation of Cell Broadcast has its own features:

• 🔹 In the firmware MIUI 12 and newer format supported ETWS (for tsunami and earthquake warnings).
• 🔹 In some models (for example, POCO F3) The alerts are displayed as a banner over all windows.
• 🔹 V MIUI 14 added support CMAS (American Standard for Emergency Alerts).

If you are wondering which technology is more reliable, remember:

• 📌 For personal notices (banking) SMS, Confirmation codes are better to use the usual SMS.
• 📌 For mass emergency alerts (natural disasters, evacuation) more reliable Cell Broadcast.

Cell Broadcast problems on Xiaomi: common mistakes and their solutions

Despite the simplicity of the technology, Xiaomi users often face problems with Cell Broadcast Service, and here are the most common ones and ways to fix them:

1. messages don't come (though they should)

Possible causes:

• 🔕 Service disabled in settings.
• 📵 Problems with SIM-card.
• 🔄 An outdated firmware version MIUI.

Decision:

1. Check if emergency alerts are enabled in the Cell Broadcast Service settings.
2. Restart the phone or remove/paste SIM-map.
3. Update the firmware to the latest version.
4. Contact the operator and see if he supports the newsletter. CB in your region.

2. Permanent “empty” notifications

Some users complain that notifications from Cell Broadcast appear on the screen, but without text.

• 🧪 Test mailings of the operator (for example, Tele2 regularly checks the system).
• 🐛 A firmware bug when the service incorrectly decodes the message.

Solution: Turn off receiving test alerts in the service settings or contact the operator for clarification.

3. High battery consumption

As mentioned earlier, sometimes Cell Broadcast Service starts to consume a lot of charge. If standard methods didn't work, try:

• 🔋 Disable battery optimization for service (Settings) → Battery → Optimizing the battery → All applications → Cell Broadcast).
• 📱 Perform reset network settings (Settings) → SIM-maps and mobile networks → Resetting network settings).
• 🔄 Reverse to an older version MIUI, If the problem occurs after the update.

4.The service does not start after the update

After major updates (e.g., with the MIUI 13 on MIUI 14) Cell Broadcast Service may stop working:

• 🔧 Conflict of System Application Versions.
• 📂 Damage to Service Files during Update.

Decision:

1. Make a factory reset (don’t forget to make a backup!).
2. Fly your phone through the Mi Flash Tool with a clean firmware installation.
3. Install root rights and manually update APK Service (for experienced users only!).

⚠️ Warning: If your phone calls or mobile internet stopped working after you manipulated Cell Broadcast Service, this may be a sign of damage to system files. MIUI. In this case, the only reliable way to restore is a complete flashing through Fastboot with an official image from Xiaomi.

Security and privacy: Myths about Cell Broadcast

Because of its hidden nature, Cell Broadcast Service is often the subject of rumors and myths, and we will see which ones are true and which ones are not.

Myth 1: “It’s a spyware from Xiaomi”

❌ It's not true. It's standard Android, and it's used by carriers around the world, and it doesn't transfer your data to Xiaomi or third parties, and its only function is to receive emergency alerts.

🔍 How do you check? Install a traffic monitoring app (like NetGuard) and see what data com.android.cellbroadcastreceiver sends. You'll see that the service only receives data, but it doesn't transmit anything.

Myth 2: “Cell Broadcast can send a message.” SMS from my phone"

❌ The service has permission to receive. SMS (He can't send them, but he can't send them, and that's confirmed by his manifesto analysis:

<uses-permission android:name="android.permission.RECEIVE_SMS"/>


<uses-permission android:name="android.permission.RECEIVE_MMS"/>




<!-- No permission to send SMS -->

Myth 3: If you turn off the service, the usual ones will stop coming. SMS"

⚠️ Partly true, but only on some firmware.

On most devices, Xiaomi Cell Broadcast Service does not affect the work SMS. However, on some custom firmware (e.g. xiaomi.eu), the service may be disrupted by the communication module, which is because informal assemblies sometimes combine system components.

Myth 4: “The service is tracking my location.”

❌ Cell Broadcast can actually show alerts based on your geolocation, but:

• 📍 Location is determined by the carrier’s base station, not your phone.
• 🔒 The service does not have access to GPS or other location sensors.
• 📡 Notifications come to all subscribers in the coverage area, not personally to you.

If you are concerned about privacy, you can:

• 🔍 View the service permissions in Settings → Annexes → Cell Broadcast Service → Permits.
• 🛡️ Install a firewall (e.g. AFWall)+) Blocking the service from the network (root required).

FAQ: Answers to Frequent Questions about Cell Broadcast on Xiaomi