How to enable frequency aggregation on Xiaomi: full instructions with nuances

Frequency aggregation (or) CA — Carrier Aggregation is a technology that allows a smartphone to use multiple devices at the same time. LTE/5G-ranges from operator to increase mobile internet speeds on Xiaomi devices (including Redmi, POCO And Mi line, it's often turned off by default, even though there's hardware support even in budget models, and you can turn it on through both hidden settings and the engineering menu, but there are pitfalls here.

Many users find that after manual activation, the aggregation is unstable or resets after rebooting. The reason lies in the features of the MIUI firmware: the manufacturer limits the functionality to “optimize power consumption.” However, if set up correctly, the speed gain can reach 30-70% — especially in low signal conditions. In this article, we will discuss all working methods, including methods for devices with a blocked engineering menu.

Important: Frequency aggregation is only effective if your operator supports this technology. In Russia, it is actively used by MTS, Beeline and Tele2 (mainly in large cities), and MegaFon limits CA for subscribers with rates below All Inclusive. Before setting up, check the coverage on the operator's website or using the NetMonster application.

Why Frequency Aggregation Is Disabled by Default on Xiaomi

The manufacturer deactivates CA for three key reasons:

1. Power consumption: Multi-frequency work at the same time increases the load on the modem, which reduces battery life by 5-15%. For low-end models (for example, the Redmi Note 12 or the POCO M5) this is critical.
2. Instable communications: In areas with poor coverage, aggregation can lead to frequent reconnections, which impairs the user experience. MIUI prioritizes stability over speed.
3. Operator certification: Not all mobile networks work correctly with CA on Xiaomi devices due to protocol implementations. For example, in Redmi 10C, aggregation may conflict with VoLTE on some base stations.

However, for users who care about top speed (like streaming 4K or online gaming), CA is justified.The main thing is to understand that in some scenarios, this can lead to an increase in ping or faster battery discharge.

Method 1: Enable through the engineering menu (#4636##)

This is the most reliable method, but it requires unlocked access to engineering settings, and newer versions of MIUI 14/15 may have different paths.

1. Open the Phone app and type in the combination: ##4636## If the code doesn't work, try ##36446337## (for models on Qualcomm Snapdragon).
2. In the menu that opens, select Phone Information (or Phone Information).
3. Scroll down to the Set preferred network type section: 📶 LTE only - for compulsory inclusion 4G (recommended). 🔄 LTE/NR auto - for aggregation 4G+5G (if the smartphone supports 5G).

Enable Carrier Aggregation

Redmi 9A

Save the settings and restart the device.

Important! Some firmware resets when you reboot, and to record changes, use the MTK Engineering Mode app (for MediaTek devices) or Qualcomm Service Mode (for Snapdragon).

Check your aggregation support by your operator|Make sure that SIM-The card is inserted into slot 1 (main card)|Charge your phone at least 50 times%|Download the application for the speed test (Speedtest, Ookla)

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Method 2: Using applications for forced inclusion

If the engineering menu is not available, you can use third-party utilities.

• 🔧 Network Signal Guru – shows the current frequencies used and allows you to manually block unstable ranges, supports forced aggregation for selected frequency combinations (for example, for example, for the use of the network signal signal, B3+B7+B20).
• 📡 4G LTE Switch is a simple tool for enabling CA on Qualcomm devices. Requires rights ADB (guideline).
• 🛠️ MTK Tweaks – for smartphones on MediaTek (for example, Redmi Note 11 or POCO X5). Allows you to edit modem configuration files.

Example of ADB configuration (works on MIUI 14+):

1. Activate Developer Mode (7 times click on the MIUI version in your phone settings).
2. Enable USB debugging in Settings → Additional → For developers.
3. Connect your phone to your PC and execute the command: adb shell settings put global carrier_aggregation_enabled 1
4. Reset the device.

⚠️ Note: Some applications (such as Network Signal Guru) require root rights to work properly, and without them, they can only display information, but not change the modem settings. On devices with a blocked bootloader, it is difficult to get root – you will need to unlock through the Mi Unlock Tool, which resets all data.

Method 3: Editing Configuration Files (for Advanced)

This method is suitable for users with root rights or custom firmware (such as LineageOS or Pixel Experience), and allows you to manually prescribe supported frequency combinations.

1. Using a root-access file manager (such as Root Explorer) go to /system/etc/firmware/mbn.
2. Find the file. carrier_policy.xml (or modem_config MediaTek).
3. Open the file in the text editor and find lines from <CarrierAggregation>.
4. Add or comment on supported combinations, for example, for aggregation of B3+B7+B20, the line would look like this: <BandCombination>3-7-20</BandCombination>
5. Save the file, set the rights to 644 (rw-r--r---) and restart the phone.

For devices on Qualcomm Snapdragon can use the utility QXDM for deep modem customization, but it requires a PC connection and knowledge of specific AT-team.

How to check if frequency aggregation works

Once you activate CA, you need to make sure that it's actually being used.

1. Install the NetMonster or CellMapper app.
2. Run a speed test (for example, in Speedtest).
3. In NetMonster, go to the tab CA Info. If aggregation works, you'll see: 📊 Primary Cell is the primary frequency (for example, the primary frequency, B3 1800 MHz). 🔗 Secondary Cell – Additional frequencies (e.g, B7 2600 MHz + B20 800 MHz). ⚡ Throughput – total speed (should exceed 100 Mbps in good conditions).

If NetMonster only displays one frequency (Primary Cell), then the aggregation is not working.

• 🚫 Operator does not support CA in your region.
• 🔄 Settings reset after rebooting.
• 📵 SIM-The card is inserted into an unsupported slot (e.g., slot 2).
• 🔋 Power saving mode is enabled (disables additional frequencies).

💡

If aggregation is not stable, try manually blocking unstable frequencies in Network Signal Guru.For example, the B28 (700 MHz) band often conflicts with the B20 (800 MHz) in urban settings.

Frequent problems and their solutions

Even after you set it up properly, users are faced with common errors, and we'll look at the most common ones.

1. the aggregation is switched on, but after 5-10 minutes it is turned off

This is related to MIUI's energy saving policy.

• 🔋 Turn off the Adaptive Battery in the settings (Settings) → Battery → Battery mode).
• 📵 Add a network management application (like NetMonster) to optimisation exceptions.
• 🔄 Use it. ADB-Command to disable restrictions: adb shell dumpsys deviceidle force-idle

2.The speed does not increase despite active aggregation

Possible causes:

• 📡 Operator base station is overloaded (often during rush hour).
• 🔌 Non-optimal frequency combinations are used (e.g, B3+B20 instead B3+B7).
• 📱 The modem of the phone is limited in power (relevant for budget models).

⚠️ Note: On some devices (e.g. Redmi Note 10 Pro with Snapdragon) 732G) aggregation works only when connected to a Wi-Fi network with active mobile Internet (LTE function)+Wi-Fi Aggregation. To check this, turn off Wi-Fi and repeat the speed test.

3.After the MIUI update, the aggregation is gone

Xiaomi often resets the modem settings after updates.

• 🔄 Repeat the settings through the engineering menu or ADB.
• 📥 Install an older firmware version (if the new version blocks the new version) CA).
• 🛠️ Use the Magisk module CarrierAggregation Enabler (requires root).

💡

If none of the methods worked, check if your model supports hardware-level aggregation. For example, the Redmi 9T (Helio G35) is physically incapable of CA, despite having an option on the menu.

FAQ: Answers to popular questions