How to prevent the Internet from disconnecting when calling on Android

The situation when during an important conversation the screen goes dark and the navigator or messenger stops transmitting data is familiar to many smartphone owners. This is due to the nature of cellular networks, where voice traffic has historically been transmitted over separate channels that are incompatible with high-speed Internet. Modern technologies make it possible to combine these streams, but often require manual activation of settings or checking equipment compatibility.

The solution to the problem lies in the transition to a standard Voice over LTE, which allows voice to be transmitted as packet data. If your operator and phone support this feature, the connection to the 4G network will not drop. However, even with support, system priorities may reset the connection to an older 3G or 2G standard for the sake of stable voice communication, which leads to temporary loss of access to the network.

In this article, we will analyze in detail the technical reasons for the connection loss and offer step-by-step guide for setting up various smartphone models. You will learn how to force activate the desired mode, check the SIM card settings and use the engineering menu for diagnostics. Sometimes one switch in the hidden menu is enough to forget about Internet interruptions forever.

Technological reasons for Internet interruptions

The main reason for the loss of network access lies in the architecture of cellular communications. In networks of the second (2G) and third (3G) generations, channels for voice and data transmission were physically separated. When an incoming call came in, the smartphone model switched from a data channel (GPRS/EDGE or HSPA) to a dedicated voice channel (CSD). Android at this moment it recorded a loss of connection to the packet network, which led to page loading stopping.

With the advent of the fourth generation standard (LTE), the situation has changed since this network was originally created for data transmission. Voice communication is just another data stream. Technology Voice over LTE (VoLTE) allows you to transmit voice within an LTE package without requiring switching to other frequencies. If this function is not activated, the phone is forced to “fall” into 3G when making a call, where simultaneous operation of voice and data is not always possible.

⚠️ Attention: Even if 4G is enabled in the phone settings, the telecom operator may not support voice over LTE in your region. In this case, the phone will automatically switch to 3G when there is an incoming call, interrupting the Internet session.

It is also worth considering the operation of two SIM cards. If one card is busy talking in 2G/3G mode, the second card often completely loses signal or access to data, since one radio module cannot simultaneously support two different communication standards at different frequencies. This is a limitation of the hardware of many budget and mid-range smartphone models.

Activating the VoLTE function in standard settings

The first step to solving the problem is to check the native settings of the operating system. Manufacturers Android smartphones such as Samsung, Xiaomi, Realme and others usually provide a convenient interface for managing network preferences. The presence of the VoLTE item in the menu means that your device is technically ready to work in the new standard.

To activate, you need to go to the settings section related to SIM cards or mobile network. The path may differ depending on the shell, but the logic remains the same: find the item responsible for voice calls via LTE and set the toggle switch to the active state. After switching on, an icon may appear next to the signal strength indicator VoLTE or HD.

• 📱 Open Settings section data-i="51">Connections and go to the Connections or Mobile network.
• 📡 Select the active SIM card, if there are several of them, and find the item Calls via LTE.
• ✅ Activate the switch and make sure that the network type is set to mode 5G/4G/3G/2G (auto).

⚠️ Attention: The settings interface may change after updating the firmware. If you do not find the described items, check the official user manual for your specific model on the manufacturer's website.

It is important to understand that activating the function on the phone side is only half the battle. The service must also be activated on the operator’s side. This is often enabled by default for new plans, but for older SIM cards you may need to send a USSD command or contact support. Without confirmation from the base station, the phone will not be able to initiate VoLTE sessions.

Settings for different smartphone manufacturers

The shells installed by manufacturers on Androidoften hide important network settings in different places in the menu. Owners of devices Xiaomi (MIUI/HyperOS) or Samsung (One UI) should be careful when searching for the necessary parameters, as the names of the items may vary.

On devices Xiaomi i Redmi there is often a situation where the VoLTE item is hidden. To display it, sometimes you need to activate a hidden menu through engineering code or an application. On smartphones Samsung the setting is usually located in the "Mobile networks" menu, but may not be available if a SIM card is inserted from an operator that is not supported by this model in a particular region.

##86583##

Entering this code in the dialer on devices Xiaomi may force you to enable or disable operator verification to activate VoLTE. A pop-up message will appear indicating that the feature is enabled or disabled. This allows you to bypass software restrictions if you are sure that your operator supports the standard.

• 🔍 For Honor i Huawei: look for the "LTE Calls" item in the mobile network settings.
• ⚙️ For Sony and Motorola: settings are often found in the "More" menu inside the wireless networks section.
• 🛠 For Realme and Oppo: use the settings search by entering the query "VoLTE" or "LTE".

What to do if the VoLTE item is not available anywhere?

If the item does not appear in the standard menu and after entering codes, your smartphone model may not physically support Voice over LTE for your operator’s frequencies. In this case, it will not be possible to solve the problem programmatically; you will need to replace the device with a more modern one.

Using the Android engineering menu

For advanced users who did not find the necessary options in the standard interface, there is access to the engineering menu. This is a hidden section of the system intended for testing equipment by developers. Here you can force set the preferred network type, which often helps to fix the smartphone in LTE mode even when a call arrives.

The menu is entered through a special code in the "Phone" application. The most common code for processors MediaTek — ##3646633##. For processors Qualcomm the code may differ, often it is ##4636##. Once in the menu, you must be extremely careful, since changing incorrect parameters can lead to loss of connection.

Parameter	Default value	Recommended value	Description
Network Mode	GSM/WCDMA/LTE	LTE Only / GSM	Operating mode radio module
VoLTE	Disabled	Enabled	Allowing voice calls via LTE
Set Preferred Network	Auto	4G/3G/2G	Network priority
DCS Mode	Normal	Normal	Antenna operation mode

In the section Telephony or Phone Information find drop-down list "Set preferred network type". Select the option containing LTE. If you select "LTE Only", the phone will stop receiving normal voice calls unless VoLTE is enabled, so it is better to choose combined modes, for example, "LTE/WCDMA/GSM".

⚠️ Attention: Changes in the engineering menu are applied instantly and may lead to temporary signal loss. If the connection is lost, simply reboot the device or select the "WCDMA/GSM" mode to return the basic connection.

Features of working with two SIM cards

Using two SIM cards makes adjustments to the work Internet connections. Most smartphones in the mid-range and budget segment have one radio module installed, which physically cannot simultaneously support high-speed Internet on one card and a voice channel on another if they operate in different standards.

When you talk on the first SIM card, the second one often goes into standby mode or is completely turned off. If the Internet is configured on the second card, it will inevitably turn off. The solution is to activate the function DSDS (Dual SIM Dual Standby) with VoLTE support on both cards, which allows you to keep both lines active in the 4G network.

• 📶 Make sure that the mobile network settings allow data transfer for both SIM cards (the function may be called "Data switching").
• 🔄 Try it swap SIM cards in the slots, since the first slot often has priority in 4G support.
• 📵 Disable the second SIM card during an important call if the first one does not provide stable Internet.

It is also worth checking whether there is a traffic limit or data saving mode, which can block background activity of applications during a call. The system may assume that the Internet is not needed during a call and aggressively save battery power by turning off the data module.

Actions if all else fails

In cases where software settings and the engineering menu did not produce results, the problem may lie deeper. It is possible that the old-style SIM card used (large plastic, cut to fit nano-SIM) does not contact the reader correctly or does not support new protocols.

Replacing the SIM card with a new one at the operator's store often solves the problem, since new chips work better with 4G/5G networks and have updated security profiles. It is also worth checking for operating system updates Androidas manufacturers often release patches that improve compatibility with local operator networks.

If this does not help, there is still the option of resetting the network settings to factory settings. This action will delete saved Wi-Fi passwords and Bluetooth settings, but will return network settings to their original state, which may resolve a software conflict.

⚠️ Note: Resetting network settings does not delete your personal files, photos, or contacts. However, you will have to re-enter passwords for Wi-Fi networks and again for Bluetooth devices.

The last argument is to contact the service center. The problem may be hardware: the antenna module or radio frequency path may have failed or require resoldering. Diagnostics by specialists will help to accurately determine whether the problem is a software or physical failure.

Frequently asked questions (FAQ)

Why does the Internet disappear, even if 4G is turned on?

Most likely, your phone does not support VoLTE technology or it is not activated. When making a call, the device switches to 3G for voice communication, and since simultaneous transmission of voice and data in 3G is not supported everywhere and not by all operators, the Internet is turned off.

Does the operator's tariff affect the operation of the Internet during a call?

Yes, some operators provide VoLTE service only on certain tariff plans. Also, the service may be paid or require a separate connection through your personal account, even if the phone supports it.

Is it possible to force the phone not to switch to 3G?

You can try using the engineering menu to set the "LTE Only" mode, but then you may stop receiving regular voice calls if the operator does not support VoWiFi or VoLTE. This is a risky method that is best used with caution.

Does the Internet work during a call via Wi-Fi?

Yes, if you are connected to Wi-Fi, the Internet will work, but only for those applications that use this connection. mobile data (LTE/3G) may still turn off if VoLTE is not configured.

Will changing your phone to a more expensive one will help?

Most likely, yes. Flagship models usually have more advanced modems and support for a greater number of frequencies and technologies (VoLTE, VoWiFi) out of the box, while state-priced models may have reduced communication functionality.