How does 2 work? SIM-Maps in Xiaomi Redmi smartphones: full instructions for setting up and using

Xiaomi Redmi smartphones have long been the standard for users who need flexibility in communication management. SIM-While cards are one of the key advantages of the lineup, not everyone knows how to set up the functionality correctly, problems with switching between operators, incorrect network priorities or a sudden disconnection of one of the cards are typical complaints faced by owners.

In this article, we will explore the unique features of implementing Dual SIM in MIUI firmware that distinguish Redmi from other brands, learn how to avoid card conflicts, set priorities for calls and mobile Internet, and which models support simultaneous 5G operation on both SIMs (spoiler: there are fewer than you think), separately discuss common errors that cause the second SIM to stop catching the network, and give a checklist to diagnose problems.

How to support Dual SIM in Xiaomi Redmi: technical details

All modern Xiaomi Redmi smartphones (starting with the 2019 Redmi Note 8) feature a Dual SIM + microSD hybrid slot.

• 📱 Use two nano-SIMs at the same time (without microSD)
• 📱 Install one nano-SIM + microSD (second microSD) SIM won't work)
• 📱 In some models (for example, Redmi Note 12 Pro)+) — two nano-SIMs + microSD (by means of a separate slot)

It’s important to understand that Redmi has Dual SIM Dual Standby (DSDS), a technology where both cards are active but only one can use mobile internet at the moment, a key difference from the flagship Dual SIM Dual Active (DSDA) smartphones, where both SIMs can be on a 4G/5G network at the same time.

In the MIUI firmware, the com.android.phone module is responsible for working with SIM, and the settings are stored in the file /data/data/com.android.providers.telephony/databases/telephony.db. When you reset or update the firmware, these parameters can get lost - so always fix the current settings before service operations.

Step-by-step setting up two SIM-card MIUI

To activate both SIM-maps, perform the following actions:

1. Insert the cards into the tray (note the position of the chip – on Redmi it should be on top).
2. Go to Settings. → SIM-maps and mobile networks.
3. Tap each SIM by name (e.g. SIM 1 or MTS) and give it a unique name (e.g., "Worker" and "Personal").
4. Turn on the switch Enable for both cards.
5. In the priority section SIM-Call cards select which card to use by default.

To set up mobile internet:

• 🌐 Go to the Mobile Network → Access point (APN).
• 🌐 Choose. SIM-map and add APN your operator (settings can be found on the operator's website or request SMS coded *99#).
• 🌐 Enable data transfer for only one SIM (The second will be disconnected from the Internet).

⚠️ Note: If, after setting up one of the SIM Not catching the network, check if the mode is activated 2G in the network settings. MIUI 14+ This parameter can be reset after the update.

Network priorities: how to make the smartphone to switch correctly

One of Redmi’s most annoying dual-SIM behaviors is the unpredictable switching between cards during calls, or SMS, which is due to a priority conflict that is set up in three places:

1. Settings → SIM-cards → SIM-card priority for calls (main parameter).
2. Settings → Annexes → Phone. → SIM-Default card (redefines the first point for calls).
3. Settings → Communications → SIM-map SMS (liaison SMS).

To avoid chaos:

• 📞 Ask one. SIM as a primary caller (e.g., work-related).
• 💬 For SMS Choose the same card or leave to ask always.
• 🌍 For mobile internet use the second one. SIM (This will reduce the burden on the main).

In the Redmi Note 11 Pro models+ and newer feature Intelligent Switching (Settings) → SIM-map → It automatically selects. SIM It's the best signal for calls, but it's often not working properly -- it's better to manually disable it.

5G and Dual SIM: Which Redmi models support the same time

Simultaneous work 5G both SIM-Maps are rare even in flagship smartphones.Redmi lineup full support for Dual 5G DSDS only:

In all other models (for example, Redmi 10 5G or Redmi Note 10T) 5G works on only one SIM, and the second automatically switches to 4G. This is due to the hardware limitations of the Qualcomm Snapdragon 480/695 modems and MediaTek Dimensity 700/810, which are used in the budget Redmi.

⚠️ Note: If you use Redmi with MediaTek (e.g. Redmi Note) 11 Helio G88), then upon activation 5G one-on-one SIM The second one may lose contact completely. 10-15 This is a well-known chipset bug that's not even fixed in the MIUI 14.

Common Problems and Their Solutions

Even with the right setup, Redmi users face typical Dual SIM issues, and here are the most common ways to fix them:

• 🔄 Second second SIM Not catching the net: Check if the Flight Mode is on for this one SIM Reset your smartphone, in the settings. MIUI Sometimes the modem initialization gets lost. MIUI 13.0.4+ Corrected the network missing error on the second SIM.
• 📵 The smartphone doesn't see one of them. SIM: Try to move the cards in places (possibly damaged contact in the slot). SIM Check the card on another phone, it can be blocked by the operator.
• 🔋 Fast battery drain: Turn off Network Search for second SIM In Settings → SIM-map → Set it for the second one. SIM regimen 2G (if not 4G).

If the problem persists, reset your network settings:

Settings → About phone → Resetting settings → Resetting network settings

This will remove all stored Wi-Fi networks and mobile settings, but often helps in Dual SIM conflicts.

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If the second SIM is constantly losing the network in the subway or elevator, turn on 2G mode for it. This will reduce power consumption and increase the stability of communication in low signal conditions.

Hidden Dual SIM features in MIUI you didn’t know about

Firmware MIUI There are several undocumented options for working with two SIM-Maps that can be activated through Developer Mode or third-party apps:

• 🔄 Forced modem switching: Enter ##4636##, select Phone Information and tap on Select preferred network type. SIM (for example, LTE only one and 3G only for another).
• 📡 Displaying Signal Strength in dBm: Activate Developer Mode (7 taps according to Version) MIUI In About Phone, then in Settings → Additionally. → For developers, turn on the Display Signal Strength. Now in the status bar, you'll see the exact signal values for each of them. SIM.
• 🔒 Lockdown SIM-Scheduled maps: Install Dual app SIM Scheduler from Google Play, which allows you to automatically disable one of the SIM At a given time (useful to save battery at night).

In models on Qualcomm Snapdragon (for example, Redmi K50) a command is available to reset the modem settings:

adb shell am broadcast -a android.intent.action.MODEM_RESET

This command helps if one of the SIMs stopped working after the firmware update.

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Starting with MIUI 14, Redmi introduced the “Separate Notifications for SIM” feature, which allows you to assign different sounds and vibrations to calls from each card. The settings are hidden in the Settings menu → Sounds and Vibrations → Call Notifications.

How to Choose the Best Combination SIM-maps for your Redmi

Not all operators work equally well in Dual SIM mode. Here are the optimal combinations for Russia and the CIS, tested on the Redmi Note 12/11/10:

If you travel a lot, look at virtual carriers like Tinkoff Mobile or SberMobile, which are based on the Big Four, but allow you to use one SIM for calls and another for cheap Internet.

⚠️ Note: Do not use two. SIM One operator (for example, two MTS) will lead to a conflict. IMSI and constant communications interruptions. MIUI There is no protection against this configuration, unlike Samsung or iPhone.

FAQ: Answers to Frequent Questions about the Dual SIM in Xiaomi Redmi