Modern smartphones of the brand Redmi And Xiaomi provide users with a wide range of functionality that often goes underappreciated. One of these hidden features is technology VoWiFi, which allows voice calls to be made over a wireless network rather than through standard cell towers. This solution is ideal for areas with poor signal but stable internet.
Enabling this feature can significantly improve connection quality in offices, basements, or country houses where GSM signal strength is minimal. However, the process isn't always straightforward and depends on the firmware, device model, and carrier support. In this article, we'll detail how to make Wi-Fi calls on Redmi and address potential obstacles.
Before you begin setup, make sure your device is connected to the network. Wi-FiThe technology won't work without an active internet connection, as voice traffic is transmitted over digital channels. It's also worth checking whether your tariff plan supports this feature, as some carriers require a separate connection.
What is VoWiFi technology and how does it work?
Technology Voice over Wi-Fi (VoWiFi) is a method of transmitting voice calls over IP, similar to how instant messaging apps work, but with integration into the standard phone book. Unlike calls via Viber or WhatsApp, here your regular phone number is used, and the other person does not see any difference in the connection method.
The main advantage is that the call is not interrupted when moving from a Wi-Fi coverage area to a strong cellular network coverage area, if the operator supports the technology VoLTEThe smartphone automatically switches data channels, ensuring uninterrupted conversations. This is especially important for users who frequently move between indoors and outdoors.
The technology requires support from three components: the smartphone itself, the SIM card, and the carrier. If even one component doesn't meet the requirements, the feature won't activate. Modern Redmi models, such as Redmi Note 12 or Redmi 13C, usually have built-in support at the hardware level.
⚠️ Please note: Call quality directly depends on the stability and speed of your internet connection. If your home network is overloaded, your voice may be interrupted or cut out.
It's important to understand that traffic in this case is consumed from your internet package, not from your call minutes, although many operators charge for such calls as regular on-net minutes. Check your plan's terms to avoid unexpected charges when calling internationally or to mobile numbers.
Checking device and operator compatibility
The first step before setting up should be verifying your hardware's capabilities. Not all Redmi models, regardless of model year, have the same set of software modules for working with IMS (IP Multimedia Subsystem). Most often, the problem lies not in the hardware, but in software limitations of the regional firmware.
You need to make sure your SIM card supports 4G/LTE, as VoWiFi is tightly coupled with the 4G infrastructure. If you have an old SIM card that you've been using for years, it's best to replace it at your carrier's store. It's free and takes minimal time.
It's also worth checking the list of operators that officially support VoWiFi in your region. Major national providers have already implemented this service, but in some remote areas or with virtual mobile operators (MVNOs), the functionality may be unavailable or unreliable.
- 📱 Make sure your Redmi model is not outdated (those released earlier than 2018 may not support IMS standards).
- 📡 Check if 4G/LTE is activated in your tariff plan settings.
- 🌍 Check with your operator to see if VoWiFi works in your current location and abroad (roaming).
- 💳 Replace your SIM card with a new one if it has been used for more than 5 years.
If you have a dual-SIM smartphone, please note that this feature can only be available on one SIM card at a time. Typically, this is the card selected as the default data or voice card.
⚠️ Note: Menu interfaces and item names may differ depending on the MIUI or HyperOS version. If you can't find an exact match, look for synonyms or similar icons.
Step-by-step instructions: activating Wi-Fi calling
Enabling this feature on Redmi smartphones typically takes no more than a minute if all prerequisites are met. The process is standard for most current firmware versions, but the path to the settings may vary slightly.
To get started, open the default "Phone" app, the one you use to make calls. In the upper-right corner of the screen, find the menu icon (three dots or a gear) and tap it. Select "Settings" from the drop-down list.
In the menu that opens, look for a section related to accounts or SIM cards. It may be called Accounts and sync or simply SIM card settingsNext, select the desired SIM card (if you have two) and find the "Wi-Fi Calling" switch.
☑️ Check before switching on
An alternative way is through the general system settings. Go to Settings → SIM cards and mobile networksSelect your SIM card and activate the toggle switch. Use Wi-Fi for callsAfter turning on, a phone icon with a Wi-Fi symbol may appear next to the network indicator.
If the toggle switch is missing or inactive (grayed out), this means the operator hasn't detected service support or the network profiles need to be updated. In some cases, rebooting the device after turning the toggle switch on helps.
| Step | Action | Expected result |
|---|---|---|
| 1 | Opening phone settings | Accessing the call control menu |
| 2 | Selecting a SIM card | Opening the parameters of a specific SIM card |
| 3 | VoWiFi activation | The Wi-Fi Calling icon appears in the status bar. |
| 4 | Checking the connection | Successful test call |
After activation, we recommend making a test call. For greater reliability, you can temporarily enable airplane mode, leaving only Wi-Fi enabled, and check whether the call is connected. This will confirm that the call is indeed being made over the internet.
Configuration depending on the MIUI and HyperOS version
Shells MIUI and new HyperOS The menu structure differs, which often confuses users. In older versions of MIUI (such as MIUI 12 or 13), the setting is often buried deep in the SIM card menu, while in newer versions it is quickly accessible or integrated into the call menu.
For owners of devices based on HyperOS It's worth paying attention to the control panel. Sometimes the VoWiFi toggle can be added to the notification shade for quick access. To do this, press and hold the Wi-Fi icon or go to the control panel editor.
Hidden codes for checking status
In some cases, the function can be activated through the engineering menu by entering the code ##869434## or ##86583##However, these codes are not guaranteed to work on all Redmi models and may be blocked by your carrier. Please enter codes with caution.
If you can't find a setting using standard methods, try using the settings search. Enter "Wi-Fi" or "VoWiFi" in the settings search bar. The system will automatically highlight the desired menu item, saving you time.
Please note that Chinese (CN) and global (Global) firmware versions may have differences in modem software. On Chinese versions, without a firmware update, this feature may not work with European or Russian carriers due to differences in IMS profiles.
- 🔍 Use the settings search by entering "Wi-Fi calling".
- 🔄 Update the Phone app and Google Play Services through the Play Market.
- 🌐 For Chinese versions, you may need to change the region in the system settings.
It's important to stay up-to-date with system updates. Xiaomi engineers regularly release patches to improve carrier compatibility. A lack of updates may be the reason this feature isn't working on newer plans.
Solution: Why VoWiFi isn't working
Even with proper setup, users may encounter issues. The most common cause is a lack of carrier support. Even if the phone indicates it can be turned on, the network may reject calls or prevent the toggle switch from being activated.
Another common problem is network conflict. If your router distributes internet on the 2.4 GHz frequency, which is subject to a lot of interference, voice quality will be poor. This technology is sensitive to latency (ping) and jitter.
⚠️ Please note: When making calls over Wi-Fi, your location may be inaccurate, as your IP address is not always tied to a specific geographic location. This is important to keep in mind when calling emergency services.
It's also worth checking whether the power saving mode is enabled in aggressive mode. The system may block background IMS services to conserve battery life, which could prevent incoming Wi-Fi calls.
If all else fails, try resetting your network settings. This won't delete your personal data, but it will return your mobile data and Bluetooth settings to factory defaults. Path: Settings → Connection and sharing → Reset Wi-Fi, mobile networks, and Bluetooth.
In rare cases, the problem lies with antivirus software or third-party firewalls that block ports used for voice traffic. Try temporarily disabling security applications and testing the connection.
Advantages and disadvantages of technology on Redmi
Using Wi-Fi Calling on Redmi smartphones has its pros and cons, which are worth weighing before committing to regular use. While it's a great solution for dead zones, there are some issues with battery life.
Benefits include high-quality audio (HD Voice), if the network allows it. It also saves battery power in weak cellular signal conditions, as the phone doesn't need to constantly boost its antenna signal to find a tower.
However, with active VoWiFi use, battery consumption may increase, as the Wi-Fi module operates in constant data transfer mode. Furthermore, switching between Wi-Fi and the mobile network may cause brief connection interruptions.
Another advantage is the ability to make calls from abroad at your home network's rates if your operator offers this service while roaming. This allows you to save significantly on communication costs while traveling.
A disadvantage is the dependence on the quality of your home internet connection. If your provider is performing maintenance or there's a power outage, you'll be without service, even if the nearby cellular network is working properly, but your phone "prefers" Wi-Fi.
| Parameter | VoWiFi | Regular connection |
|---|---|---|
| Sound quality | High (depending on the internet) | Average (depending on the tower) |
| Working in the basement | Yes (with Wi-Fi) | No |
| Consumption of minutes | At the operator's rate | At the operator's rate |
| Battery charge | Average consumption | High when signal is poor |
In conclusion, the technology is useful and useful, but it requires proper setup. Understanding how it works will help you avoid disappointment and maximize your Redmi's full potential.
Frequently Asked Questions (FAQ)
Is there an extra charge for Wi-Fi calls?
Typically, operators charge these minutes according to your basic plan, just like regular calls. However, if you're roaming, the terms may differ. Check your operator's account for details, as these rules may change.
Is it possible to make calls via Wi-Fi if the SIM card is not detected?
No, to authenticate with the operator's network and route calls, the SIM card must be active and recognized by the device. Without it, the phone will not be able to register your number in the IMS system.
Why does the VoWiFi icon disappear during a call?
This may mean the phone has automatically switched to an LTE/4G network (if VoLTE is enabled) for better quality or due to an unstable Wi-Fi connection. The icon may also disappear when the screen is locked on some models to save power.
Does this feature work if the router distributes Internet via a 3G modem?
Technically, this is possible, but the connection quality will be poor due to high latency and unstable 3G connections. The technology requires stable broadband internet access.
Do you need a special app for calls?
No, everything works through the standard "Phone" app. No additional software needs to be installed; all necessary modules are already built into the Android system and MIUI/HyperOS.