Modern smartphones Samsung Galaxy have powerful capabilities for high-speed data transfer, but sometimes by default they connect to third generation networks (3G) or even second generation (2G/E). This may occur due to operator settings, a weak signal in a particular location, or accidental changes in parameters by the user. LTE technology (Long Term Evolution) provides significantly higher page loading speeds, stable operation of streaming services and fast sending of multimedia in instant messengers.
Device owners often encounter a situation where the “4G” or “LTE” indicator disappears from the status bar, being replaced by “H+” or “3G”. In this article, we will analyze in detail how to forcefully enable the fourth generation mode on devices of the South Korean brand. We will look at standard methods through the settings menu, as well as more advanced methods using hidden engineering codes that allow you to access advanced functions of the radio module.
Before you start changing the configuration, make sure that your SIM card supports fourth generation networks and that the tariff plan does not limit access to them. It is also important to check that your phone is in an area with good signal reception, as in basements or remote areas the device may automatically switch to older communication standards to maintain a stable connection.
Checking network and SIM card support
The first step before any setup is to verify the hardware ability of your device to work in LTE networks. Not all models, especially the budget segment or older versions, are equipped with the necessary radio modules. Check the official specifications of your model on the manufacturer's website or documentation to make sure that the supported frequencies (for example, Band 3, Band 7, Band 20) match the bands of your mobile operator.
The condition of the SIM card itself is also critical. If you are using a hand-cut card from an older Mini-SIM format, or a card that is many years old, contact with the chip may be compromised, resulting in unstable operation. In some cases, telecom operators require replacing outdated cards with new ones USIM to access high-speed Internet.
⚠️ Attention: If after replacing the SIM card the phone still does not see the 4G network, the number may need to be re-registered in the operator’s database. Contact your provider's call center or support service to clarify the service status.
To quickly check the current connection status, you can use a key combination or the phone information menu. This will allow you to understand whether the device sees LTE towers in principle, even if there is no connection to them. Often the problem lies not in the settings of the device itself, but in the lack of coverage in a particular area.
Insert the SIM card into slot No. 1 if you have a dual-SIM device. On many Samsung models, priority for high-speed Internet is given to the first card, while the second can only work in 2G/3G mode for calls.
Activation of LTE through the standard settings menu
The easiest and safest way to switch the network mode is to use the built-in Android interface with the One UI shell. The path to the settings may differ slightly depending on the version of the operating system, but the general logic remains the same for all modern smartphones of the brand.
Open the application Settings and find the section Connections. Inside this menu, select Mobile networks. Here you will see an option Network mode (or “Network type”). Clicking on it will give you a list of available options. You need to select the item marked LTE/3G/2G (auto-connect) or similar wording containing the word LTE or 4G.
- 📱 Auto-connect: The phone itself selects the best available network, switching between standards without losing the connection.
- 🚀 LTE only: Forced work only in 4G networks (may lead to the inability to make calls if the technology is not turned on VoLTE).
- 📉 3G/2G: Limiting operation to old standards only (used to save battery in areas of poor reception).
After selecting the desired item, the phone may lose the network for a few seconds and then register with it again with the new standard. If the “LTE” item is not in the list or is inactive (gray), this may indicate that the SIM card is not recognized correctly or there is no fourth generation coverage in this location.
Using the engineering menu to force it on
If the standard menu does not give the desired result or the desired item is hidden by the operator, you can use the hidden service menu. This method requires caution, as changing incorrect settings may result in temporary loss of communication. To enter the menu, enter a special code in the “Phone” application ##4636##.
After entering the code, the “Testing” menu will automatically open. Select section Phone information. Scroll down to Set Preferred Network Type. In the drop-down list, select the option LTE Only for forced mode or LTE/TD-SCDMA/WCDMA for automatic switching.
##4636##
Be careful: selecting a mode LTE Only may block incoming and outgoing calls if your operator does not support voice calling technology over 4G (VoLTE). In this case, you will only be able to use the Internet. To make calls, you will have to temporarily switch back to mixed mode.
What to do if the code does not work?
On some new versions of Android, access to the engineering menu through this code is closed. In this case, you can try installing a third-party application like "Force LTE Only (4G/5G)" from the Google Play store, which creates a shortcut to this hidden menu.
⚠️ Attention: Do not change the parameters in other sections of the engineering menu if you are not sure of their purpose. Resetting the radio module settings may require a visit to a service center for flashing.
Configuring APN access points to speed up the Internet
Sometimes LTE mode is turned on, but the connection speed remains low. In this case, the problem may lie in incorrect access point (APN) settings. These parameters tell the phone through which gateway to connect to the operator's Internet. Incorrect settings can limit speed or redirect traffic through slow servers.
To check or change the APN, go to Settings → Connections → Mobile networks → Access points (APN). Select your active carrier. If the settings are lost, click on the menu (three dots in the corner) and select Reset to default. This will restore the factory settings recommended by the manufacturer and operator.
| Parameter | Value for most operators | Note |
|---|---|---|
| Name | Custom (for example, Internet) | You can set any |
| APN | internet (or operator-specific) | Key parameter |
| Authentication type | PAP or CHAP | Normally no need to change |
| APN type | default,supl | Provides Internet and GPS |
| Protocol APN | IPv4/IPv6 | Recommended modern standard |
After changing the settings, be sure to restart the device. This will allow the radio module to re-initiate the data transmission session with updated parameters. In most cases, resetting the APN to factory settings solves problems with unstable ping and low download speed.
☑️ Diagnosing slow Internet
Solving problems with displaying the 4G/LTE icon
Even if the icon is configured correctly 4G or LTE may not be displayed in the status bar, although the Internet is running at high speed. This is often a feature of the firmware or interface settings. In some regions, operators have agreed with manufacturers to display the icon H+ instead of 4G, even if the connection is established using LTE technology.
To change the display of the icon, you can try changing the region of the phone or using special applications that change system flags, but this requires root access, which is not recommended for ordinary users for security reasons. A simpler solution is to check for software updates.
The company Samsung regularly releases updates that correct errors in displaying network indicators. Go to Settings → Software update → Download and installation. If a new version of the system is available, install it. Often this solves the problem of the icon not matching the actual connection speed.
It is also worth considering that during an active voice call, the phone may temporarily switch to 3G or 2G if the technology VoLTE (Voice over LTE) is not activated or supported by the operator in your region. In this case, the 4G icon disappears for the duration of the call and returns after it ends.
The absence of the 4G icon does not always mean low speed. Conduct a speed test through a specialized application (for example, Speedtest) to really assess the quality of the connection, and do not rely only on the icon.
The impact of power saving mode on network speed
Aggressive power saving settings can negatively affect the operation of the communication module. When the battery charge drops below a certain level or Power Saver mode is turned on, the system can limit background activity and reduce transmitter power to extend the device's battery life.
This can cause the phone to search for LTE towers less often or drop the connection more quickly when the signal is weak, switching to more energy-efficient but slower 3G. For maximum network performance, it is recommended to disable hard power saving modes when stable Internet is important to you.
Check the battery settings in the section Device Maintenance → Battery. Make sure that applications that use the Internet do not have background activity restrictions set. Also, in the advanced energy saving settings, sometimes there is an option “Always turn off the mobile network in sleep mode”, which should be deactivated.
⚠️ Attention: The menu interface and item names may differ depending on the version of the One UI shell and the model of your smartphone. If you do not find the specified option, use the search in the settings (magnifying glass icon at the top of the screen).
Frequently asked questions (FAQ)
Why does the phone switch to 3G during a call?
This is the default behavior if VoLTE is not enabled or supported. To transmit voice, the phone uses 2G/3G channels, interrupting the LTE session. To avoid this, activate VoLTE in the mobile network settings if your operator provides this service.
Is it safe to use the "LTE Only" mode in the engineering menu?
You can use it, but with caution. In this mode, you may lose the ability to make and receive regular voice calls and SMS unless VoLTE is configured. You will only be left with mobile data. To return calls, you need to select a mode that supports WCDMA/GSM.
Does the case affect the quality of the LTE signal?
Yes, some cases, especially metal ones or containing magnetic elements, can shield the antenna and degrade signal reception. If you have problems connecting to LTE, try removing the case and checking the quality of the connection.
What to do if the Internet is lost after resetting the settings?
Most likely, the APN access point settings have gone wrong. Go to the mobile network settings, find the APN section and click “Reset to default”. After this, reboot your device. If this doesn’t help, request the settings from your operator via support.
Can a virus disable LTE on a phone?
Theoretically, malware can change system settings, including network settings. If you notice strange behavior of your phone, check it with an antivirus and remove recently installed applications from untrusted sources.