Xiaomi’s modern smartphones offer users a wide range of communication capabilities, including wireless calling technology. If you’re in a low-reception zone but have access to a stable Internet, Wi-Fi Calling is a lifeline, and allows you to make and receive high-quality voice calls using your home or office Wi-Fi network instead of your traditional towers.
Many owners of Redmi and Poco devices have difficulty trying to activate this option, because it depends on many factors: it is not just a switch on the menu, but a complex setup that requires support from the operator, the right firmware and the right network settings. In this article, we will discuss in detail all the nuances that will help you enjoy quality communication even in underground parking lots or buildings with thick walls.
Before you get into technical manipulation, it is worthwhile to understand that VoWiFi (Voice over Wi-Fi) is not an analogue of messengers like WhatsApp or Telegram. The call goes through a standard phone number, is charged according to your main tariff plan and does not require the installation of additional applications by the interlocutor. This is a native feature of the Android system, integrated into the shell of MIUI or HyperOS.
Verification of support function operator and tariff
The first and most critical step is to verify that your mobile operator supports the service. Even if your Xiaomi smartphone is technically capable of Wi-Fi Calling, without the appropriate setting on the provider’s side, activation is impossible. Major carriers are gradually adopting this technology, but it may not be available for old plans or certain regions.
Users often forget that SIM-The card also needs to meet modern security standards and formats, and if you use a very old plastic card that is cut off by hand under a nano-SIM, it can cause unstable operation or a complete lack of option on the menu. It is recommended to contact the communication salon to replace the card with a new one, if you have not done this for several years.
⚠️ Warning: Make sure your number does not activate blocking services or specific “anti-tip” settings that may conflict with voice traffic over Internet protocols.
To activate the service, it is often necessary to send a special USSD-The process can take anywhere from a few minutes to 24 hours, after receiving a confirmation. SMS-You can start setting up the Xiaomi device itself.
Technical requirements for smartphone and firmware
Not all Xiaomi smartphones are equally well supported by the Wi-Fi call function. This feature is usually present in mid-range and flagship devices released no earlier than 2018-2019. It is important to consider that global firmware versions (Global) may have different settings in comparison with the Chinese (China) or European (EEA) versions.
Special attention should be paid to the versions of the Android operating system and the MIUI shell. Developers are constantly improving the communication module by adding support for new codecs and encryption protocols. If you have an outdated version of the software, the option may simply be missing in the interface or work incorrectly.
Hidden Requirements for VoWiFi
The region chosen in the phone settings also matters, with some users recommending that you switch to countries where the technology is more advanced (such as India or EU countries) to unlock hidden menus, although this dependence is less pronounced in the latest versions of HyperOS.
- 📱 Device model: Check the specifications of your model on the official website, the availability of VoWiFi support is often indicated in the section "Connection".
- 🌍 Settings Region: Try changing the region in the menu"More" →"Region to India or Singapore to check for new options.
- 🔄 Base Station Version: Make sure the modem version is updated, sometimes this happens separately from the main system update.
Step-by-step activation instruction in the settings menu
If all the preconditions are met, you can move to directly activate the function in the smartphone interface. The path to settings may vary slightly depending on the version of the MIUI shell or HyperOS, but the general logic remains the same for all Xiaomi devices.
First, you have to open the main settings menu and find the connection section"SIM-maps and mobile networks. "" This is where the major switches that control voice and data are hidden.
☑️ Algorithm for enabling Wi-Fi Calling
After entering the menu of a specific SIM-If you have two cards, choose the one you want to turn on, scroll down the list. Look for Wi-Fi Calls or Wi-Fi Calling. If the switch is active, just turn it on. If it's gray or not, then one of the conditions described in the previous sections is not met.
In some cases, the system may request confirmation of your data for emergency services (E911), which is standard procedure, especially for devices destined for the US or European markets, and you will need to enter an address that will be transmitted to the operator in the event of an emergency call over Wi-Fi, even if the geolocation is disabled.
Set up network priorities and regimes
Once you turn on the basic function, you'll be faced with a priority question: A smartphone needs to know which network to use for outbound calls first when both cellular and Wi-Fi are available, a critical parameter for saving battery life and ensuring seamless connectivity.
There are usually three main modes available: the first is "Mobile Network Preferably", where the phone only uses Wi-Fi at very low cellular signal; the second is "Preferred Wi-Fi", which is relevant for areas with poor coverage; the third is "Wi-Fi Only", which completely disables the cellular radio module for calls, leaving it active only for SMS and data (unless flight mode is turned on).
| Mode of work | Description of behaviour | Recommended use |
|---|---|---|
| Mobile network is preferred | Calls are made via GSM/LTE, Wi-Fi is only used when the signal is lost. | City, good coverage area, saving Wi-Fi traffic |
| Wi-Fi is preferred | If you have Wi-Fi, the call goes through it, even if you have 4G. | Office, house with thick walls, weak operator signal |
| Only Wi-Fi. | Voice cellular network ignored completely | Zones of the "dead zone" of cellular communication, roaming without tariff |
Choosing the right mode affects how your phone moves, for example, if you leave your home, your phone must quietly switch an active call to the cellular network without breaking the connection, a feature called handover, and it's not supported by all carriers or routers.
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The correct choice of network priority allows you to avoid call breaks when leaving the range of the router and ensures a smooth transition between networks without user participation.
Diagnostics and solution of common problems
Despite the correct setup, users may experience a situation where the VoWiFi icon does not appear or calls are disrupted. One common reason is the use of dual-band routers, where the phone constantly "jumps" between the frequencies of 2.4 GHz and 5 GHz, which causes the IMS session to break.
Another problem may be aggressive energy saving in the shell. MIUI. The system can take the telephony process in the background and limit its operation when the screen is turned off. SIM-maps, and set the "No Limits" mode".
If you use VPN-They can also block the passage of voice traffic, as they change the way they do. IP-address and region of connection. The operator sees the data discrepancy and blocks the ability to establish a connection via Wi-Fi Calling for security purposes.
⚠️ Attention: When in use VPN Wi-Fi Calling calls may not be allowed. It is recommended to add exceptions for the phone's system services in the settings VPN-Apply or turn off the tunnel during conversations.
It is also worth checking the settings. DNS. Sometimes ISPs block certain ports or protocols that are necessary for VoWiFi to work. DNS-Addresses (e.g., from Google 8.8.8.8 or Cloudflare 1.1.1.1) in your router or smartphone’s Wi-Fi connection settings.
The impact of technology on communication quality and battery
Many users mistakenly believe that Wi-Fi calls consume more power than a normal cellular connection. In fact, if the cellular signal is weak, the phone spends a tremendous amount of energy finding the tower and amplifying the signal. In such conditions, Wi-Fi Calling, on the contrary, prolongs the battery life, since the Wi-Fi module operates in stable mode with low power consumption.
The sound quality of this technology is usually higher than that of standard 2G/3G networks, thanks to the use of broadband codecs (HD Voice).However, if the Wi-Fi channel is overloaded (for example, someone downloads large files or watches 4K video), voice quality may deteriorate, delays or robotic sound may appear.
It is important to note that call traffic via Wi-Fi Calling is not usually charged by the operator as Internet traffic, but goes as a package of minutes. However, if you are roaming, the rules may differ. Some operators consider such calls as incoming / outgoing in the home region, which makes them free, others can charge for international roaming, even if the call is over the Internet.
- 🔋 Energy efficiency: In the weak signal zone LTE Using Wi-Fi Calling saves you up to 15-20% battery.
- 🔊 Codec of sound: Codec support AMR-WB Provides high-definition sound comparable to messengers.
- 📶 Stability: Depends on the quality of the Internet channel; ping above 150 ms may delay conversation.