Owners of smartphones Xiaomi, Redmi and POCO Often noticed in the status bar mysterious icon "VoLTE" or"HD" This symbol means that your device uses voice over technology. LTE-Fourth generation networks: VoLTE (Voice over) LTE) — This is a standard that allows voice calls to be made directly over the network. 4G, Bypassing the switch to outdated standards 2G and 3G.
Before, when you dialed, the phone forced the Internet to reset speed to the Internet. 3G or EDGE, I want to make it possible to have voice communication. LTE-The network is capable of transmitting both data and voice simultaneously, a fundamental change in the mobile communications architecture that has become the de facto standard for today’s smartphones, including popular Xiaomi models.
Activating this feature on Chinese brand devices often requires not only operator support, but also the correct configuration of the device itself. In some cases, the icon may not appear even when the function is working, which causes confusion among users. Understanding the principles of VoLTE will help you improve the quality of communication and stability of the Internet connection during a conversation.
Technological features of VoLTE on Xiaomi smartphones
VoLTE is based on IP Multimedia Subsystem (IMS) data packet, and unlike traditional calls, where voice is encoded into narrowband, it uses the AMR-WB broadband audio codec, which provides what is called HD Voice, making the voice of the interlocutor more natural and clean, removing the characteristic metallic hue.
On Xiaomi smartphones, implementation of this feature is closely related to the firmware and region of the device. Global ROMs usually have operator certificates preinstalled, which allows the function to work out of the box. However, Chinese versions (China ROM) or re-flashed devices may require manual activation through an engineering menu or special codes.
⚠️ Warning: Forced activation of VoLTE via the engineering menu at unsupported tariffs can lead to a charge-off of money on packet traffic tariffs if the operator does not recognize the type of traffic correctly.
The biggest advantage of the technology is that it can use 4G internet and voice simultaneously, and you can play online games, navigate maps, or download files without interrupting a conversation. In the past, when you call in, the network often dropped to 3G and the loading of pages was suspended, now this process is done unnoticed by the user.
💡
If the VoLTE icon is gone after the MIUI update, check if your carrier’s APN settings have reset.
Advantages of activation HD-call-up
The switch to VoLTE has tangible benefits in everyday smartphone use, primarily in terms of sound quality, and people hear each other better even when they are in noisy or poor coverage, as noise reduction algorithms work more efficiently in LTE digital stream.
The second important aspect is the connection speed. The call setting time (from the moment you press the call button to the beeps) is reduced in the 2-3 If you had to wait before 5-7 second, then with HD-The beeps start almost instantly, especially in emergency calls or business correspondence.
The third plus is energy efficiency. The smartphone does not need to constantly switch the radio module between the frequencies of 4G and 2G/3G. Working in the same LTE band reduces the power consumption of the antenna module, which has a positive effect on the battery life of the Xiaomi device.
- 📶 Stability: No communication breaks when switching between towers with different coatings.
- 🎙️ Quality: Broadband sound makes speech more legible and lively.
- 🚀 Speed: Instant connection and ability to use the Internet during a conversation.
Compatibility of operators and tariff plans
The function requires not only support from the smartphone, but also compatibility with the infrastructure of the mobile operator. In Russia and CIS countries, the main operators (the “big four”) have long implemented VoLTE, but the connection conditions may vary.
Often the service is activated automatically when connected. SIM-However, on old plans or corporate SIM cards, the function can be blocked on the network side, in which case no settings of the Xiaomi phone will not help until the operator allows access to the network. IMS-service.
It is important to consider that when roaming abroad, VoLTE may not work or operate with restrictions, even if the local networks support the technology. This depends on interoperator agreements.
| Operator. | Status of support | Connection conditions | Features |
|---|---|---|---|
| MTS | It's working. | Automatic / USSD | 4G coverage required |
| MegaFon | It's working. | Automatically. | High quality sound |
| Beeline | It's working. | Through the appendix/LC | I need a compatible phone. |
| Tele2 | It's working. | Automatically. | Depends on the region. |
What to do if the operator is VoLTE?
Step-by-step: how to enable VoLTE on Xiaomi
The activation process on the shell MIUI or HyperOS is usually simple, but the path to settings may vary depending on the Android version. SIM-support-card 4G And mobile Internet is on.
Go to the phone's settings menu. Find the section. SIM-Select an active SIM card if you have two. In the menu that opens, look for "Use VoLTE" or "Enable VoLTE." If the switch is active (not grey), just turn it on.
☑️ Pre-insertion check
If the switch is not available or blocked, try entering a special code in the call: ##86583##. This command forcibly turns on the hidden VoLTE Carrier menu. After entering, the message "VoLTE Carrier check was disabled" should appear (which paradoxically means turning on the check and displaying the item).
In some cases, especially on Chinese firmware, you may need to activate via the engineering menu. To do this, type ##4636##, select "Phone Information" and find "Turn on VoLTE Provisioned."
⚠️ Note: Signing into the engineering menu (4636) requires caution. Do not change other parameters of the radio module if you are not sure of their purpose, this may lead to loss of the network.
Solving problems: the icon is not displayed or has disappeared
The situation where the function is enabled in the settings, but the HD or VoLTE icon in the status bar does not burn, is common.This can be a software bug of the MIUI shell. Try to restart the smartphone or temporarily turn on and off flight mode.
Sometimes the problem lies in the access point. APN. Go to the mobile network settings, select "Access Points (APN)" And reset them to the default settings, and then re-select the active operator, and the system will load the correct settings to work. IMS-service.
It's also worth checking if power saving mode is turned on: The aggressive charge saving on Xiaomi can limit background network services activity, leading to VoLTE shutdown to save battery.
- 🔄 Reboot: A banal but effective method of resetting network services.
- 📡 Reset APN: Restores the correct access parameters to the operator’s network.
- 🔋 Energy saving: Turn off the savings mode to check the stability of communication.
💡
If the VoLTE icon doesn’t appear after all the manipulations, chances are that there is no LTE voice coverage from that carrier in your region, despite having 4G internet.
Impact of firmware and region on function
Global ROM firmware versions are optimized to international standards and often contain the right configuration files for operators in different countries. Chinese versions of China ROM are tailored to local operators, so European users have to manually add profiles or refashion the device.
When installing custom firmware (e.g. Xiaomi.eu), the problem is solved by adding regional configurations. However, if you upgrade from global to Chinese or vice versa, network settings may be conflicted, in which case it is recommended to perform a complete reset of network settings.
It's important to understand that modem hardware support also plays a role, and budget models of the past may not physically support simultaneous voice and data operation in certain frequency bands, regardless of the software version.
If you are planning to purchase a new Xiaomi smartphone specifically for use in roaming or specific conditions, check the list of supported frequencies (Band) and the availability of VoLTE certification from official dealers.