Modern smartphones, including the popular Xiaomi Redmi 9C, are equipped with a variety of communication-enhancing technologies that ordinary users often don’t know about. One of these features is VoLTE, an acronym that increasingly flashes in the status bar of the device next to the network indicator. Many owners of budget and mid-budget devices notice this icon and wonder if I need it, if it traffic and how to manage this option if it interferes or, on the contrary, is necessary.
In this article, we will explain in detail what is behind this term, why operators are actively implementing this technology and how it affects the autonomy of your Redmi 9C. You will get comprehensive information on how to activate hidden features or, conversely, completely deactivate the function if your operator does not already support it fully or you prefer a classic mode of operation.
So, as you go into the technical details, it's important to understand that Long Term Evolution was originally designed as a data technology, and voice was a secondary challenge, but with the development of fourth-generation networks, it's possible to transmit voice traffic directly through LTE channels, which has come to be called Voice over LTE. It's not just a marketing ploy, it's a real step forward as a communication.
What is VoLTE Technology and How Does It Work?
Voice over LTE is a high-speed wireless standard for mobile phones and data terminals. Unlike traditional calls that use 2G or 3G networks, VoLTE transmits voice calls as a data stream over a 4G network. This allows you to simultaneously talk and use high-speed Internet without switching network modes, which is especially true for owners of Xiaomi Redmi 9C, who actively use navigators or messengers during a conversation.
The main advantage is the speed of the connection: when dialing via VoLTE, the connection is almost instantaneous, whereas in older networks it took several seconds to switch channels, and the sound quality is much higher thanks to the use of wide-range codecs, which makes the voice of the interlocutor more natural and clean, removing the characteristic “metal” echo.
But the adoption of the technology requires support from several parties: first, your carrier must provide this service in your area; second, the SIM card must be of the appropriate standard (usually USIM); and third, the smartphone itself, in this case the Redmi 9C, must have the appropriate software and settings in the firmware.
⚠️ Warning: Using VoLTE can consume slightly more battery power in areas of uncertain signal reception 4G, Because the communications module is in constant data transmission mode, if you're in a low-cost area, the battery can run out faster than usual.
It is important to note that the voice transmission is through IP-It's a protocol, but it's not usually charged as Internet traffic, and operators set up a QoS channel that takes precedence over the normal Internet. Therefore, worrying about the fact that the minutes of conversation will eat up your package of gigabytes is usually not worth it, but the terms of a specific tariff plan are always better to check with the provider.
For Xiaomi users, this technology is often enabled by default in modern MIUI firmware if the device is certified to work with local operators. However, in some cases, especially when using imported versions of smartphones or custom firmware, the feature may be hidden or unstable.
Advantages and Disadvantages of Using VoLTE on Redmi 9C
The transition to the new communication standard has both obvious advantages and certain nuances that Redmi 9C owners should consider. Understanding these aspects will help you make an informed decision about using the feature.
Among the key advantages are:
- 🚀 Instant connection: dialing and horns start almost immediately after pressing the call button, delay is minimal.
- 🎧 HD-sound quality: voice is transmitted over a wide frequency range, which improves speech intelligibility, especially in noisy places.
- 🌐 Simultaneous operation: you can stay online 4G while talking, download files or play online games without dropping the speed to 3G.
- 📶 Improved coverage: In some cases, signaling 4G breaks through better than 2G/3G, This allows you to make calls from basements or remote locations where old networks no longer work.
Despite the obvious advantages, there are also disadvantages that can be decisive for some users: the main disadvantage is the dependence on 4G coverage. If you are in an area where only 2G or 3G catches, VoLTE will not work, and the phone will automatically switch to standard calls, and there may be compatibility issues when roaming in other countries where your carrier does not have VoLTE agreements with local networks.
Another nuance concerns device compatibility: While the Xiaomi Redmi 9C technically supports the standard, not all operators are added to the firmware whitelist.This can lead to situations where the VoLTE icon burns, but calls are disrupted or go through 3G. In such cases, manual settings or modem flashing are required.
| Parameter | Regular call (2G/3G) | VoLTE call (4G) |
|---|---|---|
| Connection speed | 3-7 seconds | 1-2 seconds |
| Sound quality | Narrowband (telephone) | Broadband (HD) |
| Internet during a call | Reduced to 2G/3G or shut down | It works at full speed 4G. |
| Battery consumption | Standard. | A little higher in the weak signal areas |
So if you value connectivity and speed, VoLTE is the preferred option, but if you travel frequently to remote areas with unstable 4G, it may be wiser to switch to classic mode for battery savings and a more stable, albeit slower, connection.
Verification of support function by operator and device
Before trying to turn on or disable VoLTE on Xiaomi Redmi 9C, You need to make sure that your SIM card and plan support this service, and not all operators provide this feature for free or automatically. USSD-Requests or activate the service in the personal account.
You can do a visual check of the device's support. Look at the top status bar of the screen. If you see a VoLTE or HD icon next to the network designation (4G or LTE), then the function is active and working. If the icon is not there, it does not mean that the phone does not support the technology, it may be hidden in the settings or not activated by the provider.
For a deeper check, you can use the engineering menu that is available on all Xiaomi smartphones, which is a hidden part of the system designed to test the hardware. To get there, open the Phone app and type in the combination:
##4636##Once you enter the last star, the Testing menu automatically opens. Select Phone Information. Here you will see a lot of technical options. Find the VoLTE Provisioned or Enable VoLTE switch. If the switch is there and it is active (or can be activated), your Redmi 9C hardware and software are ready to go.
⚠️ Warning: Be careful with the engineering menu, changing the parameters you don't know can cause the communication module to malfunction or the network to disappear completely.
It is also worth checking the list of supported operators in the settings. MIUI. Go to Settings. → SIM-maps and mobile networks → Select a SIM card. → Use VoLTE. If you see a list of carriers or a switch that you can activate, it means that the system has recognized the SIM card as compatible.
How to enable VoLTE through standard MIUI settings
In most cases, activating the feature on the Xiaomi Redmi 9C does not require complex manipulations. The MIUI shell interface allows you to manage this option through the standard settings menu. This is the most secure and recommended way for ordinary users.
To enable, follow the following steps:
- 📱 Open the main menu and go to the Settings section.
- 📡 Select a point. SIM-maps and mobile networks.
- 🔢 Click on your operator name or Settings under the desired SIM-card.
- 🔘 Find the Use VoLTE switch and activate it.
If the status bar icon doesn't appear after the switch is turned on, try restarting the device. Sometimes the system takes time to register with a new type of network. Also make sure that the network type settings have a preference for Preferably 4G (LTE). If you select 3G Only or 2G Only mode, VoLTE will not work physically.
☑️ Checklist of VoLTE activation
In some versions of MIUI firmware, the path may be slightly different. For example, the option may be directly in the notification curtain. Pull down from the top to open the control center, and look for the VoLTE icon. If it's not in the visible part, click on the pencil or edit button to add this toggle to the quick access panel.
It is worth remembering that even with the setup enabled, the phone may not display the icon if it is in the coverage area only. 3G. The icon only appears when the device is connected to the tower. 4G and ready to be called through IP-protocol.
Activation through the Engineering Menu and Hidden Commands
If the VoLTE option is missing or inactive (blacked out) in the standard settings menu of the Xiaomi Redmi 9C, you can try activating it via the engineering menu, a method often required for devices purchased in China (Global Version), or for operators that are not on the standard MIUI list.
As mentioned, log in is via code ##4636##. Once you enter the Phone Information menu, scroll down the list. You are interested in VoLTE Provisioned. If the switch is off, turn it on. Immediately after that, the status bar should display the corresponding icon.
However, on the new versions of Android and MIUI Access to this menu through USSD-You can block the code, and you can use Activity Launcher or similar tools to run hidden activity, and you can find a line in the activity list that contains com.android.phone and the word VoLTE, and you can run it.
What if the VoLTE switch does not appear in the engineering menu?
There is another method that is more complex and requires the presence of a computer - the use of the computer. ADB-By connecting the phone to a PC with debugging. USB, You can send a command to change the global parameter:
adb shell settings put global volte_enabled 1This command is forced to enable the technology at the system level, but its effectiveness depends on whether the support of the operators is embedded in the modem's firmware itself, and if the software phone can't work with your operator's VoLTE, the command will not work.
How to turn off VoLTE on Xiaomi Redmi 9C
There are times when you need to turn off the feature, such as if you notice that the Redmi 9C battery is running too fast, or calls are often broken, or if you are roaming and want to avoid unnecessary expense, you may also need to turn off if you use old SIM cards that do not work properly with the new standard.
The easiest way is to go back to the Settings menu. → SIM-maps and mobile networks and switch the switch to "Off" and use VoLTE to "Off" after that the phone will stop initiating calls through the phone. 4G It will use standard channels. 2G/3G voice-over.
If the switch is not in the settings, but the function is active (the icon is on), you can turn it off via the same engineering menu ##4636##. Find the VoLTE Provisioned item and uncheck the tick. The icon should disappear instantly.
In extreme cases, you can change the type of network, and in the Network Selection menu (also available through the engineering menu or the developer settings), you can select WCDMA/GSM (3G/2G) mode, which completely prohibits connection to 4G, and therefore VoLTE will not work, but this will deprive you of high-speed Internet.
⚠️ Warning: When you turn off VoLTE, make sure you have backup data enabled if you want to continue using the internet while you're talking. 2G/3G Simultaneous voice and data transmission (technology) HSPA+) Not all operators and not all tariffs are supported.
Once the function is disabled, the phone may need to reboot to apply the changes. Check the quality of the connection by calling someone. If the sound gets worse or the connection is established longer, this is a normal consequence of switching to the old communication standards.
Problem Solving and Frequently Asked Questions
Xiaomi Redmi 9C users often face a number of typical problems when setting up VoLTE.For example, the icon may disappear on its own.This is usually due to the fact that the phone lost its 4G signal and moved to the 3G zone. Once the 4G coverage is restored, the icon should return.
Another common problem is that there is an icon, but calls don't pass or are reset, which may indicate a conflict of APN settings or an incompatible operator profile, in which case it is recommended to reset the factory access point settings in the mobile menu.
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Main idea: The stable operation of VoLTE depends on the three: a proper SIM card, 4G coverage and the correct settings of the smartphone. If one of the elements falls out, the function will not work.
Also worth mentioning is the impact of flashing. If you have installed Custom ROM, VoLTE support may be compromised, as proprietary modem files may be lost or replaced, and in such cases, returning to stock MIUI often resolves the problem.
Below are answers to the most popular questions that Redmi 9C owners have about this technology.