Modern smartphones of the series Redmi Note from the company Xiaomi have extensive functionality that is often hidden deep within system settings. One such useful, but not always obvious, feature is technology VoWiFi, which allows you to make voice calls over a wireless network. Many users notice the corresponding icon in the status bar but don't understand its purpose or know how to activate this option to improve call quality.
The technology's essence lies in transmitting voice traffic not through standard cellular operator channels, but through internet protocols. This is especially relevant for owners Redmi Note, who often experience poor signal reception in rooms with thick walls, basements, or remote areas. Instead of intermittent sound and constant disconnects, you get clear HD sound, comparable to messaging apps, but using your regular phone number.
In this article, we will take a detailed look at what lies behind the abbreviation Wi-Fi CallingHow to set up this feature correctly on devices MIUI And HyperOSWe'll also look at possible reasons why it might not be working. Understanding these nuances will help you stay connected even in areas where cellular coverage is virtually nonexistent.
How Voice over WiFi works
Technology Voice over WiFi (VoWiFi) is a standard for transmitting voice calls over wireless networks. Unlike popular apps like WhatsApp or Telegram, which use their own servers and require the recipient to install the app, VoWiFi is integrated directly into the standard phone book and dialing interface. For the owner Redmi Note The calling process looks absolutely normal, the only difference is which channel the sound goes through.
When you dial a number, your smartphone Xiaomi analyzes available networks. If the cellular signal is weaker than a certain threshold and the Wi-Fi connection is stable, the system automatically routes the call via Internet Protocol. This requires carrier support and proper equipment configuration. It's important to understand that IP telephony In this case, it works at the operator level, so billing is based on your main tariff plan, not on internet traffic.
⚠️ Attention: Call quality directly depends on the speed and stability of your wireless connection. If your router is overloaded or the signal is weak, your voice may sound robotic or intermittent, even if the Wi-Fi indicator shows full strength.
The key benefit is saving battery power in areas with poor reception. Smartphone Redmi There's no need to constantly boost the antenna's power to search for a cell tower, significantly reducing power consumption. Furthermore, the technology allows for seamless switching between Wi-Fi and mobile data during a call if you move out of the router's coverage area, although this feature is dependent on carrier support.
How to check and enable VoWiFi on Redmi Note
Activating the function on smartphones Xiaomi may differ depending on the firmware version (MIUI 12, 13, 14 or new HyperOS) and the regional version of the device. In most cases, the setting is located in the standard system settings menu. First, make sure that your Redmi Note connected to a Wi-Fi network, as without an active connection the option may not be available to switch.
Go to the main settings of your device and find the section responsible for SIM cards and mobile networks. This is where you'll find a switch that's often overlooked. The interface may offer separate settings for each SIM card if yours does. Redmi Two cards are installed, which allows for flexible management of call priorities.
The sequence of actions usually looks like this:
- 📱 Open
Settingsand select the itemSIM cards and mobile networks. - 📶 Click on the name of the desired mobile operator in the list of active SIM cards.
- 🔘 Find the switch Wi-Fi calling (or Wi-Fi calls) and activate it.
- 📞 Select your preferred network type: "Wi-Fi Preferred" or "Wi-Fi Only" if you want to block the cellular network completely.
☑️ Check before switching on
If you don't find this switch in the specified location, try searching through the settings. Enter "Wi-Fi calling" or "VoWiFi" in the search bar. MIUI This often allows you to quickly access the desired menu, bypassing complex navigation paths. It's also worth checking whether the option is hidden in the additional menu, which is accessed by clicking the three dots in the corner of the screen.
Operator requirements and tariff compatibility
Availability of this function in a smartphone Redmi Note — that's only half the battle. For this technology to work, support from your mobile operator is required. In Russia and the CIS, major market players have already implemented this service, but it may not be available on older tariff plans or may require a separate subscription.
Operators may charge an additional fee to activate the service or, conversely, offer it for free to retain customers. It's important to distinguish between technology support and subscriber-side activation. Even if the switch is present in the phone's menu, the icon won't be activated without operator permission. VoWiFi will not appear in the status bar.
Comparison of conditions of the main operators (conditional data, requires verification):
| Operator | Need for connection | Tariffs | Peculiarities |
|---|---|---|---|
| MTS | Automatic / USSD | According to the tariff | Works in roaming |
| Megaphone | Personal account | According to the tariff | VoLTE is required |
| Beeline | Automatically | According to the tariff | HD voice |
| Tele2 | Personal account | According to the tariff | Depends on the region |
Activation often requires sending a special USSD code or using the operator's mobile app. After activating the service on the server side, it is recommended to reboot Redmi Noteto re-register the device to the network and receive new settings profiles. In some cases, the carrier profile is updated automatically in the background.
What if my operator doesn't support VoWiFi?
If your current carrier doesn't offer this service, you can use third-party calling apps, but they won't integrate with the standard dialer. The alternative is to change your plan or switch to a different provider that supports the technology in your region.
Setting priorities and operating modes
After activating the function in the menu Redmi Note The system offers the ability to fine-tune smartphone behavior. It offers several usage scenarios that optimize data usage and connection quality. Choosing the right mode is especially important if you have a limited home internet connection or an unstable signal.
"Mobile Network Preferred" mode means the phone will use Wi-Fi for calls only when there's no cellular signal or it's extremely weak. This is the safest option for those concerned about unexpected data usage, although this is less relevant with today's unlimited data plans. Network priority Determines which channel will be selected first when an incoming call arrives.
The "Wi-Fi Preferred" mode forces the smartphone to prioritize the wireless network for voice calls. This is ideal for offices, shopping malls, and apartments with poor cell tower coverage. If the Wi-Fi network loses connection during a call, the phone will attempt to switch to the mobile network, subject to roaming settings and coverage.
There's also a "Wi-Fi Only" option, which completely disables cellular network use for voice calls. In this mode, if you leave the router's range, incoming calls will be blocked and outgoing calls will fail. This is useful as a "digital detox" or in situations where you need to ensure that calls are made over a secure corporate channel and not over a public cellular network.
Possible problems and solutions
Despite the well-established technology, users Redmi Note Users may encounter various errors. Often, the problem lies not with the phone itself, but with the router configuration or temporary glitches on the carrier's end. Understanding the nature of the error will help quickly resolve the issue and restore a good connection.
One of the common problems is the absence of the icon HD or a handset with a Wi-Fi symbol after enabling the feature. This may mean the phone is connected to the network, but has failed to register with the IMS (Internet Media Services Subsystem). In this case, switching to airplane mode or completely rebooting the device can help. It's also worth checking whether data usage for background system processes is blocked.
Another common scenario is dropped calls or interrupted voices. This indicates bandwidth issues. If many devices are connected to the router, downloading heavy content (4K video, games), there may not be enough resources for voice traffic. In such cases, adjusting the settings can help. QoS (Quality of Service) on the router, giving priority to voice packets.
- 🔄 Reset network settings: Go to
Settings → Connection and sharing → Reset Wi-Fi, mobile networks, and BluetoothThis will delete saved passwords, but often solves registration problems. - 📡 Checking frequencies: Make sure you are connected to a 5GHz network if your router is close by, as it is less crowded than 2.4GHz.
- 🛡️ Antiviruses: Third-party memory cleaning applications or antivirus programs may block VoWiFi system processes. Try disabling them temporarily.
⚠️ Attention: When resetting your network settings, you will lose your saved Wi-Fi passwords. Make sure you remember your router access details before performing this operation.
The Impact of VoWiFi on Battery Life and Security
Using VoWiFi technology on Redmi Note has its own specific energy consumption characteristics. On the one hand, not constantly searching for a cellular signal saves battery life. On the other hand, the active Wi-Fi module, which must constantly maintain a connection to instantly receive a call, also consumes power. The balance depends on the specific processor model and system optimization. HyperOS.
In very weak cellular signal conditions (1 bar or "no service"), using VoWiFi significantly extends battery life. The smartphone doesn't need to waste power boosting the antenna signal. However, if you're in a strong 4G/5G area, switching to Wi-Fi for calls may provide a minimal boost in battery life or even slightly increase battery consumption if the Wi-Fi module is underperforming.
From a security standpoint, VoWiFi calls are encrypted by the operator in the same way as regular voice calls on LTE networks. However, if you use public Wi-Fi hotspots in cafes or airports, there is a theoretical risk of data interception (man-in-the-middle), even though voice traffic is protected by encryption protocols. For maximum security, it is recommended to use personal networks or a VPN, although the latter may interfere with VoWiFi.
It's also important to note that Wi-Fi calls may provide less accurate geolocation than cell tower calls. This can be critical when calling emergency services (112, 102, 103), as the operator may not receive your exact location coordinates. In such situations, the system may automatically switch to the cellular network for location determination.
Why does the VoWiFi icon disappear during a call?
This could be due to temporary packet loss on the Wi-Fi network or the phone switching to another access point (roaming between routers). It could also be caused by the operator updating the network configuration in real time.
Does making calls over Wi-Fi use up internet traffic?
Technically, data usage is used, but operators typically don't charge separately for calls to home network numbers. International roaming rules may vary, so it's best to check with your provider.
Is it possible to use VoWiFi without VoLTE support?
In most cases, VoWiFi requires VoLTE to be enabled, as they use similar IMS architecture. However, on some models Redmi and some operators only allow you to use Wi-Fi Calling.
Does this feature work if the router distributes internet via a 4G modem?
Yes, the technology doesn't differentiate between internet sources. The main thing is that the channel is stable and has sufficient bandwidth to transmit voice packets in real time.