Owners of Xiaomi, Redmi and Poco smartphones often face a situation where after switching on a new device or replacing a SIM card, mobile Internet does not automatically start working, a common feature due to the fact that the phone’s memory may not have the current APN access point parameters for your particular operator. Without this data, the device simply does not know which gateway to transmit traffic through, even if the signal level shows 4G or LTE.
The configuration process does not require any technical knowledge, but mindfulness when entering data is critical. An error in a single symbol of the server address or the access point name will make the Internet unavailable. In this article, we will examine in detail all the steps from the physical installation of the chip to manually registering settings for any mobile operators.
In addition, we will touch on the choice of slots, as some models of smartphones of Chinese brands have restrictions on the operation of networks of the fourth generation depending on which connector the card is installed.
Physical installation and choosing the right slot
The first step is always to physically install the card correctly. Modern Xiaomi smartphones use a combined tray, where one of the slots can be combined with a microSD memory card.
When you take the tray out with a paper clip, you notice the shape of the tray, and you usually have a diagram on the inside of the tray or on the frame of your smartphone that tells you which slot is the main slot. SIM-maps, then to ensure the work 4G Both cards must be supported by the standard at the same time. USIM and were released relatively recently.
⚠️ Warning: Never try to insert SIM-Mechanical mismatch of contacts can lead to short circuit and combustion of the motherboard power controller.
Once the device is installed and turned on, the system must automatically identify a new card. If a mobile network setup notification appears on the screen, this is a good sign. However, if the network status remains “Emergency Calls Only” or “No Service”, it is worth checking whether the slot is activated in the software.
☑️ Installation verification SIM
Activation of slots and choice of map for the Internet
After successful installation of SIM card and input PIN-If you have the code (if it was installed earlier), you need to make sure that the slot is active. MIUI or HyperOS, SIM card management is placed in a separate menu. Go to Settings, then select SIM-maps and mobile networks.
Here you'll see a list of cards installed. Make sure the switch opposite the SIM card is activated. If the slider is gray and doesn't press, it may not be physically visible and you'll need to reboot or re-install. You can set a separate destination for each card, one for calls, one for data only.
Pay special attention to the item "Use for mobile Internet", in this menu you choose which SIM card will be connected to the network. If you have tariffed traffic on one card and unlimited traffic on another, the right choice here will save you money, and in this section you will configure your preferred network type.
- 📶 Preferred network type: select “Preferred” LTE», The phone is always trying to catch it. 4G, I didn't get stuck on the slow. 3G.
- 📞 Calls through SIM: Here you can choose which card will be used by default for voice communication, or leave a request for each call.
- 💬 SMS Default: Similar to calls, sets the main card for sending messages.
Manually configuring the APN access point
The most important step, if the Internet doesn't work automatically, is manually setting up an APN (Access Point Name), which is the gateway through which your phone connects to the carrier's network, and often automatic settings come with a delay or are buggy, so manually creating a profile is the most reliable method.
To access these settings, go on the Settings path → SIM-maps and mobile networks. Select the SIM card you're setting up the Internet for and find "Access Points (APN)». In the list that opens, click the “New Access Point” button or the “plus” icon in the upper right corner of the screen.
A form will open with many fields. You don't have to worry: you only need to fill in 3-4 parameters, the rest can be left blank or by default. The name can be any, for example, "My Internet", but the field "APN" requires accuracy. Here you enter the address of the operator gateway, which depends on your service provider.
| Operator. | The Name field. | APN field. | Type APN |
|---|---|---|---|
| MTS | MTS Internet | internet.mts.ru | default,supl |
| MegaFon | Megafon Internet | internet | default,supl |
| Beeline | Beeline Internet | internet.beeline.ru | default,supl |
| Tele2 | Tele2 Internet | internet.tele2.ru | default,supl |
Once you have entered, be sure to click the "More" button (three dots in the corner) and select "Save." Then go back to the access point list and activate the profile you just created by putting a marker next to it. Without saving and activating, the settings will not take effect.
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After saving the APN settings, be sure to turn on and off In-Flight mode to apply the changes without restarting the phone.
Configure MMS and additional parameters
Although most users are switching to instant messengers, MMS is still used by banks and government agencies to send notifications. Multimedia messages often need to fill in additional fields in the AP settings (the same place you prescribe an APN) to work properly.
In the advanced settings of the access point, find the fields MMSC, MMS-proxy MMS-This data is unique to each operator and is usually available on their official websites in the support section. If these fields are left blank, the Internet can work, but the pictures in the messages will not be uploaded.
There is also the option "APN Protocol." In 99% of cases, it must be set to IPv4/IPv6. If you choose only one protocol, there may be conflicts with modern carrier networks that are actively implementing the new addressing standard. Make sure that the access point type contains the default,supl,mms value if your operator requires multimedia support.
⚠️ Attention: When setting up MMS Make sure that the access point profile does not have a password or login installed unless the operator explicitly requires you to enter them.
Solving Network and 4G Definition Problems
There are times when the settings are entered correctly, but the phone stubbornly shows 3G or H+, ignoring the 4G coverage area. First of all, check if your SIM card supports the USIM standard. Older cards cut out of large format or obtained many years ago may not have a chip to work on LTE networks.
Smartphones imported from China (global or domestic) may not support certain Band frequencies used by operators in your area, for example, if the carrier uses Band 20 and the phone does not support it, 4G will not be caught in buildings or outside the city.
You can use an engineering menu or a special application to diagnose, but the easiest way is to reset your network settings. Go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. This action will return all network settings to factory values and often resolve software conflicts.
What is a network reset?
Security SIM-maps and PINs
Securing access to the SIM card is an important security aspect. PIN-The code prevents unauthorized people from using your card on another device, but there is a risk: if you enter the card three times incorrectly, the card is blocked, and you will need a code to unlock it. PUK.
Code. PUK It's usually shown on the plastic card that you give out when you buy a SIM card, and if you lose it, you can find it in the operator's office or in the communication room when you present your passport. PUK-10 times leads to the final lock of the SIM card, which can only be restored by re-releasing a new one.
In Xiaomi smartphones, the management of these codes is in the Protection menu SIM-maps (the path may differ depending on the version) MIUI, Sometimes it's in the "Passwords and Security" section. PIN-code to more convenient or disable its request when turning on the phone, although the latter reduces the level of protection.
- 🔒 PIN-code: 4-8 Numbers are requested at each turn on the phone.
- 🔑 PUK-8 digits, used only for unlocking in case of error PIN.
- ⛔ Blocking: occurs after 10 erroneous input attempts PUK, map becomes unusable.
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Save a photo of your plastic card with the code PUK In the cloud, or write the code to a secure location, loss of plastic when blocked. SIM-The map will create unnecessary difficulties with the restoration.