How to improve signal quality on Xiaomi smartphones: from firmware to antennas

Have you noticed that your Xiaomi has become worse at catching the network? Call from the basement and the person hears you like a barrel? 4G-Is the Internet disappearing or returning at the speed of dial-up? The problem of weak signal is familiar to many owners of Redmi smartphones, POCO And Mi, especially in urban areas or suburban areas, but don't blame the operator, because 70 percent of the time, the device settings, the software that's out of date, or the hardware constraints are to blame.

In this article, we’ll look at 10 proven ways to improve the signal on Xiaomi, from basic (reboot and change the SIM) to advanced (configure modems through the engineering menu), you’ll learn how to make your smartphone work consistently with the LTE Band 20 (800 MHz), why the Mi 11 catches 5G worse than the Redmi Note 12, and what to do if the network disappears after the MIUI update. All methods are tested on models from 2020-2026 and do not require root rights.

Warning: on smartphones with a Snapdragon 8 Gen 1/2 processor (for example, Xiaomi 12 Pro, 13 Ultra), signal problems are often associated with a hardware defect of the antenna module - they can only be solved in the service center.

1. Check the basic network settings

Start with the obvious: maybe the smartphone just "forgot" how to connect to the network. → SIM-maps and mobile networks → [yours SIM] → Network type and select:

• 📶 4G (preferably, if you are interested in the stability of the connection;
• 🚀 5G/4G/3G/2G (Auto: if you want maximum speed (but be prepared for frequent switching between standards);
• 🔄 Only 3G — temporary solution for places with poor coverage 4G (like the subway).

If 4G Only is not available, your carrier does not support VoLTE (voice calls over 4G).In this case, the smartphone will be forced to switch to 3G during calls, which can cause communication interruptions.

⚠️ Attention: POCO F3 Redmi Note 10 Pro with firmware MIUI 14+ sometimes get tweaked APN. If after changing the type of network the Internet does not appear, go to Settings → Mobile network → Access points (APN) and click "Reset to default values».

2. Update firmware and modem

Manufacturers regularly release updates to improve the operation of modems, for example, MIUI 14.0.5 for Xiaomi 13T fixed a bug with a loss of signal when switching between 5G and 4G. To check the relevance of the software:

1. Open Settings → About the phone → System update.
2. If you have a new version, install it (preferably via Wi-Fi).
3. After the update, restart the smartphone.

If there are no updates, but the problem remains, try updating only the modem (without full firmware).

Download the latest version of MIUI Fastboot ROM for your model |

Unpack the archive and find the NON-HLOS.bin file in the image | folder.

Connect your phone to your PC in Fastboot mode (Plug Volume Down + Power)|

Follow the command:

fastboot flash modem NON-HLOS.bin

Reboot the device with the command fastboot reboot-->

⚠️ Warning: Don't try to flash a modem from another model - it will lead to total loss of network! NON-HLOS.bin It must strictly conform to your device.

For models on MediaTek (e.g. Redmi 10C, POCO M5), instead of NON-HLOS.bin, look for the md1img file and flash it with the command:

fastboot flash md1img md1img

3. Activate VoLTE and VoWiFi

VoLTE (voice calls over 4G) and VoWiFi (wi-fi calls) are significantly improving communication quality in low signal areas. On Xiaomi, they are often disabled by default.

1. Go to Settings. → SIM-maps and mobile networks → [yours SIM].
2. Activate the VoLTE and VoWiFi switches.
3. If there are no options, install the latest firmware (see Section 2).

For models with Snapdragon 865/870/888 (e.g. Mi 11, POCO F3 GT) manual activation may be required via the engineering menu:

1. Please type in the phone keyboard ##4636##.
2. Select Phone Information.
3. In the Set preferred network type, select LTE/UMTS auto (PRL).
4. Return and activate VoLTE provisioned.

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If VoLTE activated, you stop calling, try turning off Voice Improvement in Call Settings, a feature that sometimes conflicts with the technology.

4. Optimize antenna settings through the engineering menu

The engineering menu contains parameters that allow you to manually configure the antennas. Be careful - incorrect changes can lead to loss of the network.

1. Open the Phone app and dial ##4636##.
2. Select Phone Information.
3. Scroll down to the Network block.
4. Note the parameters: Signal strength is the current signal level (in dBm). Optimal: from -85 to -65. Network type is the standard used (LTE, UMTS, etc.). Service state is the connection status (should be In service).

If the signal is weak (e.g. -110 dBm), try to force the frequency to be blocked.

1. In the engineering menu, select Set preferred network type → LTE only.
2. Then click Band Selection and only mark the ranges your carrier supports (check on its website). For example, for MTS in Russia, it is Band 3 (1800 MHz), Band 7 (2600 MHz) and Band 20 (800 MHz).
3. Save the settings and restart the phone.

5. check the physical condition of the antennas and SIM-map

The weak signal isn't always associated with the software settings, and it's often the fault of:

• 📱 Damaged. SIM-card: microcracks on the chip or contamination of contacts. Try to wipe the card with alcohol or replace it in the operator's cabin.
• 📡 Disconnected antenna - after falling or disassembling the phone, the antenna cable could move away from the motherboard. 9A, POCO M3).
• 🛡️ Metal case or magnetic holders -- they shield the signal. Take off the case and check the difference.
• 🔋 Bloated battery, it can push the antenna module, and if the phone is swelling, replace the battery immediately.

To check the antenna for hardware damage:

1. Call from your phone to another number and put your palm around the top of the body (where the antennas are located), and if the signal goes missing, the antenna is a problem.
2. Try using the phone without a case in different places, and if the signal improves, it's the case.
3. Put it in. SIM-If the signal is stable, the problem is your Xiaomi.

⚠️ Attention: On Xiaomi 11T Pro and 12 Pro antennas are located in the upper and lower parts of the case. If the signal disappears when holding the phone in a certain way, it can be a defect in design - contact the service under warranty.

6.Use external signal amplifiers

If all software methods have been tried and the signal is still weak, consider hardware solutions:

• 📶 Cellular repeater is suitable for home or office. Examples: Huawei B525, TP-Link 4G+ M7650. Cost: From 5,000 ₽.
• 📡 Directed antenna - mounted on the roof and connected to the repeater. Effective in rural areas. Price: from 3,000 ₽.
• 🔌 USB-modem with an external antenna, for example, ZTE MF833V. It can be used as an access point for the phone.
• 📱 Signal amplifier case, like WaveCatcher, suitable for travel, but the effectiveness is controversial, but some users have reported an improvement of 10-15%.

For models with Wi-Fi Calling (VoWiFi) support, the alternative is to connect to and call through stable Wi-Fi, which is especially true for Xiaomi 13 and newer, where VoWiFi works without additional settings.

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Before buying an amplifier, check if it supports the frequencies of your operator. For example, for Beeline in Russia you need Band 3 and Band 7, and for Tele2 - Band 20.

7. Reset the network settings

If the signal is lost after updating or changing the firmware, resetting the network settings will help, which will delete all stored Wi-Fi networks, passwords and mobile Internet settings, but return the modem parameters to the factory.

Instructions:

1. Go to Settings → About the phone → Reset settings.
2. Select Network Reset (not to be confused with a full reset!).
3. Confirm the action and wait for the reboot.
4. After turning on the phone, reconfigure the connection to the mobile network (enter PIN-code SIM, Choose the type of network, etc.).

If the reset didn't work, try to roll back to the previous version of MIUI.

1. Download the old firmware from the Xiaomi Firmware Updater website.
2. Go to Settings → About Phone → System Update → Three Dots (menu) → Select a firmware file.
3. Install the downloaded file and restart the phone.

⚠️ Attention: Firmware rollback can lead to locking the bootloader on models with a locked bootloader (for example, the official Xiaomi for Russia). Before rolling back, check the bootloader status with the fastboot oem device-info command - Device unlocked: true should be.

8. Check compatibility with the operator

Not all Xiaomi smartphones work equally well with different carriers.

• The Redmi Note 11 Pro+ does not support the Band 20 (800 MHz), which is heavily using Tele2 in the regions.
• The POCO X4 Pro has 5G issues at n78 (3500 MHz) in MTS.
• Xiaomi 12T is not certified to work with Yota in Russia.

To find out what frequencies your smartphone supports, use the service FrequencyCheck. Enter the model of the device and compare with the frequencies of your operator (you can find them on the official website).

If it turns out that the smartphone does not support key frequencies, the options are:

• Change the operator to a more compatible one (for example, from Tele2 to MTS for Redmi Note 10).
• Buy an external modem with the desired frequencies and use the phone in access point mode.
• Sell the device and choose a model with full range support (e.g. Redmi Note 12 Pro+ instead of Note 11 Pro+).

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Kimovil’s website compares the frequency support of different Xiaomi models by region, which will help avoid buying an incompatible device.

FAQ: Frequent questions about the signal on Xiaomi