Many owners of Xiaomi smartphones face a situation when in the upper corner of the screen instead of the usual and desirable letter 4G or LTE appears mysterious letter H or H+. This phenomenon is often bewilderment and concern, especially if you are used to high speed loading pages and streaming video. Understanding the difference between these designations is critical for comfortable use of mobile Internet in modern conditions.
Owners of Redmi and Poco devices often notice that switching between modes is automatic and not always predictable. The letter H stands for HSPA+, which is a transitional stage between 3G and full 4G, providing speeds of up to 42 Mbps, which is well below the capabilities of LTE. At the same time, 4G mode (Long Term Evolution) offers a completely different level of performance, allowing you to watch high-resolution video without buffering and quickly download heavy files.
In this article, we will take a closer look at the technical differences, the reasons for the forced switch to a lower speed, and learn how to manually manage these settings. You will learn why your Xiaomi can get stuck on H, even if the operator tower supports 4G, and what hidden system parameters can affect signal quality.
Technical differences between H and 4G communication standards
To understand which mode is better, we need to look at the facts and specifications of wireless networks. HSPA+ (designated H or H+), often referred to as 3.5G, is an evolutionary development of third-generation networks. It uses modulation technologies that allow theoretical speeds of up to 42 Mbps, but in practice these figures are often lower due to the load on the base station.
On the other hand, LTE (Long Term Evolution), known to users as 4G, is a full-fledged fourth-generation standard that uses a fundamentally different packet-based network architecture that provides minimal latency (ping) and high bandwidth. For Xiaomi owners, this means stable video calls and fast real-time navigator operation.
The difference in data speeds between the two standards can be huge. While H+ allows you to comfortably browse social networks and listen to music, 4G is necessary for streaming 4K video, online gaming and fast downloading of large amounts of data. Modern applications are becoming more “heavy”, requiring high-speed connection for full-time work.
- 🚀 Speed: 4G provides speed 100 Mbps to 1 Gbps, whereas H+ rarely exceed 20-30 Mbps in real-world conditions.
- ⏱️ Latency (Ping): On the networks LTE ping 10-20 MS, which is critical for online gaming, while H+ giveaway 50-100 ms and above.
- 📡 Technology: LTE fully IP-oriented architecture, enabling more efficient use of the spectrum.
Why Xiaomi is switching from 4G to H
Automatic switching of a smartphone to a lower communication standard is a routine behavior of the system, designed to keep the connection where the 4G signal is unstable. MIUI or HyperOS algorithms constantly analyze the signal level and, if it falls below a certain threshold, reset the connection to H or 3G so that the call does not interrupt and the data does not stop transmitting at all.
A common cause is physical obstruction or distance from the operator's tower. Building walls, basements, dense development, or simply being on the boundary of the cell coverage can cause a loss of high-frequency LTE signal. In such cases, the Xiaomi phone prioritizes connection stability over its speed, choosing a longer-range but slower H standard.
Network congestion also has an impact: during peak hours, when a single base station has a huge number of subscribers, an operator can redistribute traffic, disconnecting some users from 4G or reducing their priority, as a result, the indicator on the screen changes, and Internet speeds decrease, this is especially true at mass events or in the city center in the evening.
⚠️ If your phone is constantly "jumping" between 4G and H even in the confident reception zone, this may indicate a software failure in the communication module or a problem with the SIM-Try to remove and wipe the SIMKI contacts.
How to Force Only Enable 4G on Xiaomi
If you're in a confident reception zone, but the phone is stubbornly holding the H, you can try to get the device to use only fourth-generation networks, this is done through a hidden engineering menu that is available on most Xiaomi smartphones, a method that is useful when automatic network selection is not working properly.
To enter the radio interface settings menu, open the Phone app and dial ##4636#. Once you enter the last star, the hidden testing menu will open. You will select Phone Information. In the list that opens, find Set preferred network type.
In the drop-down list, select the option containing LTE Only. Be careful: after turning on this mode, your smartphone will stop receiving and making normal voice calls if the operator does not support VoLTE (Voice over LTE) technology. The Internet will only work through 4G, and in its absence, communication will disappear completely.
☑️ Pre-insertion check LTE Only
How do you get back to normal?
The impact of setting SIM-mapping the speed of the Internet
In smartphones Xiaomi with two SIM-There's a lot of priority conflict, and it allows you to choose which card you want to use to transfer mobile data, and it's important to understand that the speed of the Internet depends not only on the SIM that you choose, but also on which slot you're using, especially on older devices.
On some Redmi budget models, the first slot can support 4G, while the second is limited to 3G/H. If your main SIM with an Internet tariff is inserted into the second slot, you will not physically be able to get 4G speeds, no matter how much you configure the software part.
It's also worth checking the APN settings. Sometimes operators change access settings, and the old settings on the phone may not correctly route traffic, causing a drop in speed. You can reset the APN settings to factory ones on the mobile network menu by selecting the appropriate SIM card.
- 📱 Slot SIM: Make sure that the SIM card for the Internet is installed in a slot with support 4G (usually Slot 1).
- ⚙️ Access Point: Check to make sure that the settings are in place APN the correct profile of your operator has been selected (for example, Internet.mts.ru).
- 🔄 Switching: When using two sims, make sure that the map with traffic is selected in the "Mobile Network" settings.
Comparative table of network characteristics
For clarity, here are the main parameters that distinguish the H+ standard from LTE. These data will help you to objectively assess why the transition to 4G is so important for the modern smartphone user.
| Parameter | H+ (3.5G) standard | 4G (LTE) standard |
|---|---|---|
| Maximum speed | up to 42 Mbps | up to 1000 Mbit/s (theorem) |
| Average real speed | 5 - 15 Mbps | 20 - 100 Mbps |
| Delay (Ping) | 50 - 100 ms. | 10 - 30 ms. |
| Transmission technology | Channel/packet switching | Package only (IP) |
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Even the minimum 4G speed (10-15 Mbps) is often more stable and responsive than the top H+ speed, thanks to the low latency.
Problems with the operator’s coating and equipment
Remember that a smartphone is a receiver and is limited by the carrier’s infrastructure. If your area has not had an operator tower upgrade in years and does not support LTE frequencies, no Xiaomi can magically turn H into 4G. In such cases, the letter H on the screen is the ceiling available in this location.
There are also blind spots and interference zones, and metal framed buildings, thick concrete walls, or terrain can shield high-frequency 4G signals, which are worse at penetrating obstacles than low-frequency 2G/3G. In the back of the room, a phone can catch 4G, and when it goes out around the corner, it loses it.
Sometimes the problem lies in the very SIM-If you use a SIM card issued by a card. 5-7 years ago, it may not support new encryption protocols or (frequency bands) used to 4G. In this case, replacing the SIM card with a new one from the operator can solve the problem of switching to H.
⚠️ Attention: Forced incorporation of the regime"LTE Only" in the engineering menu can lead to complete loss of communication in areas where the coverage is 4G Use this method only for testing or in safe areas.
Optimizing MIUI settings for stable 4G
The MIUI operating shell has its own energy-saving features that can aggressively limit modem operation. The Power Saving function can reduce transmitter power or more often put the communication module into sleep mode, which is perceived by the user as a speed drop or switch to H.
It is recommended to check the battery settings for system processes responsible for communication, and it is also worth turning off the Wi-Fi Assistant function if it is turned on. This tool tries to switch you to mobile Internet if Wi-Fi is weak, but sometimes does this incorrectly, causing constant reconnection and changing network standards.
In some cases, network resets help, and this action will return all mobile Internet, Bluetooth and Wi-Fi settings to factory values by removing possible configuration software errors. You can find this option along the way: Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth.
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Periodic flight mode switching on for 10-15 seconds helps the phone reconnect to the nearest and less busy base station, which often returns the 4G icon.