Modern smartphones Xiaomi have a wide range of functionality, often hidden deep within system settings. One of the most useful, but not always obvious, features is the ability to make voice calls over a wireless network, known as VoWiFiThis technology allows you to maintain a connection even in areas with extremely weak cell tower signal, as long as there is an internet access point nearby.
Many users face the problem of standard cellular service not penetrating the thick walls of a basement or remote office. In such situations Wi-Fi Calling It becomes a real lifesaver, providing crystal-clear sound and a stable connection. However, despite hardware support in most current models, software activation often requires intervention.
In this article, we will take a detailed look at how to enable this feature on devices with the shell. MIUI And HyperOSYou'll learn not only about standard activation methods but also about hidden engineering menus that allow you to bypass restrictions imposed by some carriers. Understanding how this technology works will help you stay connected under any circumstances.
⚠️ Note: The menu interface may vary slightly depending on the firmware version and regional version of your smartphone. If you don't find the item you're looking for, check your carrier's official help documentation.
What is VoWiFi and why is it needed?
Technology Voice over Wi-Fi VoWiFi (Voice over WiFi) transmits voice traffic over an internet protocol, similar to how instant messaging apps work, but at the system level. This means the standard dialer is used to make calls, rather than a separate app. The quality of the connection in this case directly depends on the speed and stability of your wireless connection.
The main advantage is the ability to make calls from places where the regular cellular network signal is absent or extremely weak. Xiaomi We're actively implementing support for this feature in our devices, as it reduces the load on operator base stations and improves the user experience. This is especially relevant for large metal-frame buildings or homes with thick walls.
It's important to understand that this feature requires support from your mobile operator. Even if your phone is technically ready, you won't be able to activate it without the appropriate service on your SIM card. Modern data plans often include this feature by default.
Checking operator support for the feature
Before you go into your smartphone settings, you need to make sure that your mobile operator provides the service. VoWiFiMajor companies are gradually implementing this technology, but the list of supported devices and plans may change. Often, it's necessary to replace the SIM card with a new one that supports 4G/LTE standards.
Verification is performed through the subscriber's personal account or by contacting customer support. Some operators require filling out an application or activating a paid service, although most have already switched to a free service. Without confirmation from the network, all activation attempts on your phone will be unsuccessful.
- 📞 Log in to your personal account on the operator's website and find the section with additional services.
- 💬 Write a support question in the support chat VoWiFi for your phone model.
- 📱 Make sure that 4G/LTE service and LTE voice calls are enabled on your SIM card.
It's also worth keeping in mind that roaming may affect the functionality of this feature. Wi-Fi calls abroad may be charged as local calls if you're in your carrier's home region, but rules vary. Always check the terms before traveling to avoid unexpected charges.
Basic activation via the standard menu
In most cases, if your carrier and phone support the technology, the toggle appears automatically. You don't need to do anything other than find the desired slider in the settings. Here's the shell's workflow: MIUI or HyperOS usually unified and logical.
To get started, open the main settings menu and find the section for SIM cards and mobile networks. This is where all voice-related settings are located. The path may vary slightly, but the keywords remain the same.
Go to Settings → SIM cards and mobile networksSelect the desired SIM card if you have two. In the list that opens, look for "Wi-Fi Calling" or Wi-Fi CallingIf the switch is grayed out or missing, proceed to the next sections of the article.
☑️ Enablement algorithm
Activation via the engineering menu (Secret code)
Sometimes, the operator and phone support a feature, but the manufacturer "forgot" to add a switch to the menu for a specific region. In this case, the engineering menu comes to the rescue. XiaomiThis is a hidden section designed for hardware testing, but is also accessible to regular users.
To enter the testing menu, you need to use a special code in the Phone app. Dial the combination ##869434##If everything went well, you'll see a message saying "Wi-Fi Calling enabled" or something similar. After that, the toggle switch should appear in the regular settings menu.
However, on new versions Android And MIUI This code is often blocked. If entering the code doesn't work, you can try an alternative method through the Activity app. You'll need a third-party utility, such as Activity Launcher, available in Play Market.
Once you've installed the app, search for "wifi" in the activity search. You'll need to find the component associated with com.android.phone or com.miui.simtoolkitOnce you launch the desired activity, you will be taken to a hidden menu where you can force it to turn on. VoWiFi.
⚠️ Warning: Be careful in the engineering menu. Changing unknown parameters may result in unstable operation of the communication module or a complete network failure.
What to do if the code doesn't work?
If the secret code doesn't work, it means your firmware version blocks access to this method. In this case, the only solution is to use the Activity Launcher app to search for hidden Wi-Fi Calling settings activity within the phone's system processes.
Setting up via the Mi Sim Toolkit app
On devices Xiaomi often a pre-installed system application Mi Sim ToolkitIt serves as a bridge between the operator's settings and the phone. Configuration messages that can activate hidden functions are often sent through it.
Open the app Mi Sim Toolkit From the settings menu or search for it. If your carrier has transferred the necessary profiles, you'll see an option related to VoLTE/VoWiFi settings. Tapping it will send a request to the carrier's server and retrieve the configuration file.
After receiving the settings, you may need to reboot your device. This is a standard procedure for the new network settings to apply. If the app is empty, your carrier didn't transfer the profile automatically, and you'll need to use other methods.
Comparison of activation methods
There are several ways to enable this feature, each with its own unique features. Some methods are safer, while others require more technical expertise. The method you choose depends on your phone model, firmware version, and carrier policy.
Below is a table to help you navigate the methods and choose the one that best suits your situation. It takes into account the difficulty of implementation and the likelihood of success.
| Method | Complexity | Risk of error | Efficiency |
|---|---|---|---|
| Standard menu | Low | Absent | High (if available) |
| Engineering code | Average | Short | Average (depending on version) |
| Activity Launcher | High | Average | High (for hidden menus) |
| Mi Sim Toolkit | Low | Absent | Depends on the operator |
If none of these methods help, it's possible that your specific phone model isn't certified for use with the carrier in your region. In this case, your only option is to wait for firmware updates.
Possible problems and their solutions
Even after successful activation, connection stability issues may persist. Often, the problem lies not with the phone, but with the router. Older router models may not prioritize voice traffic correctly, leading to interruptions.
Try switching to the 5 GHz frequency if your router supports dual-band mode. This will ensure lower latency and a more stable voice channel. It's also worth checking that Wi-Fi power saving mode isn't enabled on your smartphone.
- 📶 Make sure your Wi-Fi signal is strong enough (at least 2-3 bars).
- 🔋 Disable battery saving for your phone's system processes.
- 🔄 Reset network settings in the menu
Connection and sharing.
Sometimes, simply resetting your network settings can help. This will delete saved Wi-Fi passwords and Bluetooth settings, but it often resolves issues with registering on new network types. After resetting, you'll need to re-enter your wireless network passwords.
⚠️ Note: Resetting network settings will delete all saved Wi-Fi passwords and Bluetooth pairings. Make sure you remember your home network access details.
Why do calls drop when I leave the house?
This is normal behavior. The phone needs to switch from Wi-Fi to the cellular network (handover). If your carrier doesn't support eSRVCC technology, the call may be disconnected when switching between networks.
Frequently Asked Questions (FAQ)
Does using VoWiFi affect my billing?
In most cases, a minute of Wi-Fi call is charged the same as a standard minute according to your plan. However, if you're roaming internationally, the rules may differ: the call may be counted as an incoming/outgoing call in your home region, which is significantly cheaper. Check with your carrier.
Is it possible to use Wi-Fi calling without a SIM card?
No, technology VoWiFi Linked to a phone number and SIM card. Without an active SIM card, the feature won't work, as authentication occurs through the carrier's network. For calls without a SIM card, use instant messaging apps.
Why doesn't the Wi-Fi handset icon appear in the status bar?
The icon may not be displayed if the feature is enabled but there is no active call, or if the interface settings MIUI hide it. The icon also only appears after successful registration with the operator's network for VoWiFi. Check your status bar settings.
Does this feature work on custom firmware?
On custom ROMs (LineageOS, Pixel Experience), VoWiFi support is often absent or unstable due to the lack of proprietary drivers and carrier certificates. With stock ROMs, it's much more likely to work.