Despite its age, the Xiaomi Mi 9 remains a powerful device capable of delivering high performance in everyday tasks. However, users often face the problem of low connection speeds, which is especially noticeable when streaming video or downloading heavy files. In most cases, the problem lies not in hardware constraints, but in the software settings of the MIUI operating system or conflicts of network protocols.
Before embarking on radical measures such as resetting, basic diagnostics are needed to assess the current state of the network, often caused by accumulated cached application data or an incorrect communication module after a firmware update, and optimization begins with an analysis of which type of connection is unstable: mobile Internet or Wi-Fi.
In this guide, we will take a detailed look at all the ways you can improve stability and data rate. You will learn about the hidden features of the engineering menu, the right DNS settings, and the methods to get the most out of your Mi 9. Follow the instructions consistently to eliminate software errors.
Diagnostics and resets of network settings
The first and most secure step is to completely reset your network settings, which does not affect your personal files, photos or contacts, but removes stored Wi-Fi passwords, Bluetooth settings and mobile network configurations, which eliminates errors that result from a system update or a change in carrier.
To perform the procedure, go to the Settings menu → About Phone → Reset. Here you will need to select the option Reset Wi-Fi, mobile Internet and Bluetooth settings. The system will warn you of the consequences, after which you will need to confirm the action through the input of the screen unlock pin code.
⚠️ Note: After reset, you will have to re-enter passwords from all Wi-Fi networks and re-connect Bluetooth devices such as headphones or smartwatches.
Users often forget that the aggressive energy savings in MIUI can limit the background activity of network modules. If the problem persists after the reset, check the battery settings for system processes. Make sure that the "No Limits" mode is selected for the Google Play service and system components, allowing background services to update without delay.
Optimizing Wi-Fi Connection Settings
Wireless is the most common source of speed issues.The Xiaomi Mi 9 smartphone supports modern standards, but by default may not be set to maximum performance.The first thing to make sure is that the device is connected to the 5 GHz band, which provides higher bandwidth compared to the traditional 2.4 GHz.
To force switching or checking settings, go to Settings → Wi-Fi → Click on your network name. Here you can find the option "Use static IP", but for most home routers, automatic address acquisition (DHCP) works more stable. If the router supports 802.11ac or Wi-Fi 6 standards, make sure that the router settings do not include compatibility mode with older devices, which can artificially lower speeds.
- 📶 Turn off the Wi-Fi Assistant function in Wi-Fi settings so that your phone doesn’t try to switch to mobile internet at the slightest drop in signal.
- 🔒 Change the encryption method on the router WPA2-AES or WPA3, As the old encryption protocols (TKIP) Significantly reduces the speed of data transmission.
- 🔄 Reboot the router by disconnecting it from power for 30 seconds to clear its internal memory and recalculate communication channels.
Another important parameter is DNS. Standard ISP servers often respond slowly, and replacing them with fast public DNS from Google or Cloudflare can significantly speed up the opening of web pages. To do this, select "DNS Settings" in the Wi-Fi settings and type in 8.8.8.8 and 8.8.4.4 addresses.
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Use the Wi-Fi Analyzer app to find the least congested channel in your home and switch the router to it via a web interface (typically 192.168.0.1).
Setting up mobile Internet and choosing a network
When it comes to mobile data, the right APN configuration is key. Operators change their network settings periodically, and automatic settings can become outdated. For the Xiaomi Mi 9, manually creating a profile optimized for high speeds is important.
Go to Settings. → SIM-maps and mobile networks → Choose. SIM-map → Access points (APN). Create a new access point. In the "Type" field. APN" Please write default,supl and in the "Protocol" field. APN" choose IPv4/IPv6. This will allow the device to use the most modern and fast routing protocol provided by the operator.
| Parameter | Recommended value | Description of the impact |
|---|---|---|
| Name. | Fast Internet | Arbitrary name for convenience |
| APN | internet | Depends on the operator (mts, beeline, etc.) |
| Protocol | IPv4/IPv6 | Priority to the new addressing standard |
| MCC/MNC | Change | Country and Operator Codes (automatically) |
Also worth paying attention to the function "Preferred network type." From the mobile network menu, select Preferably LTE or 5G/4G/3G/2G (auto). Forced on only 4G/LTE can help in areas of unstable reception, preventing constant switching between standards, which "eats up" traffic and time.
⚠️ Note: Do not manually set the parameters MCC and MNC, If you're not sure if they're right for your region, it can completely block the ability to log in via a SIM card.
☑️ Checking the mobile network settings
Using an engineering menu to amplify the signal
Snapdragon-based smartphones, which include the Mi 9, have a hidden engineering menu that allows you to adjust antenna sensitivity and base station connection priorities, accessed through a standard call.
Dial the code ##4636##. In the menu that opens, select Phone Information. Here you can see real signal strength (RSRP) and noise level (SNR). If the signal level is very low, try changing the setting "Install preferred network type" on LTE Only (LTE only), if you are in the zone of confident reception, or return to automatic mode if the connection is lost.
How to interpret the signal values in dBm?
The same menu also has a button called "Run Ping" that allows you to check the stability of the connection to the nearest operator server in real time, and if packet loss is high, the problem is likely on the operator's side, and software will not solve it on the phone.
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The engineering menu is a powerful tool, but changing unknown parameters can cause the modem to run unstablely.
Third-party applications and traffic cleanup
Sometimes the speed drops because the background apps consume the entire channel available. MIUI has an inbuilt optimization tool, but third-party utilities can provide more detailed control. However, be careful: many Internet accelerators are just advertising spaces and do not give a real effect.
The most effective method is to use traffic monitoring apps like GlassWire or the built-in monitor in Security → Data Use. Check if the 2GB game is being updated in the background or if cloud storage is synchonized. Disabling automatic updates in the Google Play Store and App Store over Wi-Fi alone will free up the channel for your current needs.
It is also worth mentioning DNS-applications like 1.1.1.1 or Intra. They encrypt DNS-requests and often allow you to bypass the ISP locks, which indirectly affects the speed of page loading, installing such an application can be a solution if the provider throttling (artificially slows down the speed) of certain services.
- 🚫 Remove antiviruses with traffic check feature if they are not system-based, as they create additional latency.
- ⚡ Use the "Flight" mode on 10-15 Seconds for forced re-registration in the operator’s network, which often gives a temporary increase in speed.
- 🧹 Clean your browser and messenger cache regularly, as a crowded cache can slow down the processing of network requests.
Hardware limitations and the influence of covers
You can't discount the physical factors. Xiaomi Mi 9 has a glass case and a specific arrangement of antenna modules. If you use a case with metal inserts, magnetic rings for mounting in the car or too thick silicone, it can shield the signal.
Remove the case and check the speed. If the difference is noticeable, replace the accessory with a thinner or made of materials that do not interfere with the passage of radio waves. Also check the charging connector: oxidation of contacts can cause interference, especially if you try to use the Internet while charging with a cheap power supply without shielding.
⚠️ Attention: Cheap cables USB Power supplies can create strong electromagnetic tips that jam the Wi-Fi and Bluetooth signal at 2.4 GHz.
In rare cases, the problem may be the degradation of the antenna module after falls or moisture. If software methods do not help, and other devices at the same point the network works perfectly, you may need to diagnose in the service center.