The second call feature is one of the most sought-after features in the modern smartphone’s arsenal, allowing you to keep important calls out of the way. Owners of Xiaomi, Redmi and Poco devices often face a situation where when a call is incoming, the caller hears the beeps, and nothing appears on the screen, or the call is simply reset. This can occur due to a network reset, firmware update or operator features. The second call is not just an option on the menu, but a network service that requires the correct configuration on the phone side and on the cellular operator’s side.
Shell interface MIUI or the new HyperOS can hide the necessary switches in the depths of the system menus, making their search not obvious to the average user. USSD-codes that allow you to control this function directly through the command, which is especially important if the standard menu does not respond. In this article, we will discuss in detail all the ways to activate, configure and troubleshoot the problems associated with waiting for a call on Xiaomi smartphones.
Understanding how subscriber switching works will help you manage communication effectively without losing any important contact. SIM-And the network's availability is a key success factor that many people forget about.
Principle of operation and types of switching
Before we go into technical manipulation, we need to understand exactly what the second call function is: it's a network service provided by a carrier that allows you to hold a current conversation and take an incoming call. Without an active service on the operator's side, no settings in the phone will work, because the switch simply will not send a signal about the incoming connection to your device during a busy line.
Xiaomi smartphones have a number of scenarios for how a second call will be made. You can choose how the device will respond: automatically make the first hold call, send a busy call, or ignore the second call. Android call management is based on GSM and 3GPP standards, but manufacturers add their interface solutions for convenience.
- 📞 Waiting for a call: You hear a signal, see a notification, and can switch to a new person by putting the first person on hold.
- 📵 Deviation: The second caller hears a “busy” signal or hits the answering machine immediately without interrupting your current conversation.
- 🔄 Switching: the ability to complete one conversation and instantly respond to another, or to combine them into a conference call.
Importantly, the function depends on the type of network. In 2G and 3G networks, the waiting mechanism for a call has been worked out for decades and works steadily. However, when you switch to VoLTE (Voice over LTE), the mechanism of voice data transfer changes, which sometimes leads to conflicts or delays in displaying the notification of a second call.
Activation through the standard settings menu
The easiest and safest way to enable the feature is to use the phone's built-in menu. The path to settings may vary slightly depending on the version of MIUI or HyperOS, but the logic remains the same: You need to open the Phone app (green handset), which is the standard dialer on the system.
Once you open the app, click on the three dots in the top right corner of the screen to call the context menu, and select Settings. In the list that opens, look for the section associated with accounts or SIM cards. It's usually called "Calling Accounts," or it just lists yours. SIM-map (SIM 1, SIM 2).
☑️ Checking call settings
Select the SIM card you want to activate the service on. In the menu that opens, look for "Additional Settings" or "Other Settings." That's where the "Incoming Calls During Conversation" or "Waiting for a Call" switch is hidden. Activate the slider, and the phone will send a request to the operator's server to enable the service.
If the switch is active but the function is not working, try turning it off and turning it on again.The system should show a message "Settings done" or "Service activated." In some versions of the firmware, it takes a few seconds to get a response from the base station.
Use of the USSD-service-management codes
If the phone menu does not give a result or the activation point is missing, help come to the rescue. USSD-These are commands that are sent directly to the operator's server in real time, bypassing the interface constraints of the Android shell. GSM-code#.
To check the status of the service, dial *43# and press the call button. In a few seconds you will receive a pop-up message or SMS from the operator with information about whether the call waiting service is enabled. The same code is used to force activation, but sometimes you need confirmation through the menu that will appear on the screen.
List of basic codes for call management
There are also codes to disable the feature if it interferes with you. Code #43# deactivates the wait for a call.
⚠️ Attention: When in use USSD-If the request does not pass, you may be in a bad reception zone or there are not enough funds on the balance to charge service requests (although more often they are free).
Setting up for two SIM-map
Xiaomi smartphones are famous for their support of two SIM-This creates additional nuances in the setting of the second call, each SIM card has its own independent settings in the system, which means that activating the service on Sim 1 will not affect the work of Sim 2».
You need to repeat the activation procedure for each card separately. Go to the call settings, select the first SIM card and turn on the call waiting. Then go back, select the second SIM card and do the same. Remember that the tariff plans may differ: on one card the service may be free, and on the other it may be paid.
When you call a second SIM card incoming, while you talk on the first, the phone can behave differently depending on the settings. If the second SIM card has call waiting on, you will see a notification. If not, the call can be reset or forwarded. The switching logic in dual-symbol devices is more complicated, since the radio module is often one, and it cannot physically support two active voice channels simultaneously in 2G/3G networks without DSDA (Dual SIM Dual Active) technology, which is rare.
Most modern Xiaomi models use DSDS (Dual SIM Dual Standby) technology, which means that both cards are waiting, but only one is active. When a second call is made to the same SIM card (which is being talked about), waiting will work, and if the call goes to the second SIM card, the behavior depends on the “if not available” redirection settings.
Table: Comparison of activation methods
For ease of perception, we have systematized the main ways to include a function in a comparison table, which will help you choose the most suitable option depending on your situation.
| Method | Difficulty | Dependence on the interface | Reliability |
|---|---|---|---|
| Settings menu | Low. | High (depending on the version of MIUI) | Medium |
| USSD-code# | Low. | Absent. | Tall. |
| Personal account of the operator | Medium | Absent. | Tall. |
| Engineering menu | Tall. | Medium | Low (risky) |
As can be seen from the table, the use of USSD-The operator’s codes or personal account are often a more reliable way than finding a switch in the phone’s menu, which may contain bugs after an update.
Problem Solving: The function does not work
There are times when all the settings are correct, but the second call does not come. The subscriber hears the beeps, and you have silence on the screen. The first reason is always to check the status of the service with the operator. Sometimes on the network side there are failures, or the service was forced to turn off when the tariff changes.
The second common cause is a conflict with the Security app or Xiaomi's built-in number detector. Aggressive spam filters can block a second call, deeming it suspicious. Try temporarily disabling unknown number locks or updating the detector databases.
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Reboot in flight mode: If the second call stopped working suddenly, turn on In-Flight mode for 10 seconds, and then turn it off. This will force the phone to re-register in the network and update the service profile on the Internet. SIM-map.
It's also worth checking if the "if busy" redirect is enabled. If it's active and leads to voicemail or another number, the second call will go there before it rings on your screen. Check the redirect settings in the same menu where you turned on the call wait.
⚠️ Note: If you use third-party calling apps (e.g. Truecaller, Google Phone instead of system), the second call settings may not apply globally. MIUI Dialer to check.
The Impact of VoLTE and Wi-Fi Calls
Modern networks 4G and 5G They use VoLTE technology to transmit voice, which improves the quality of the communication, but changes the way the second call works, and in VoLTE networks, the second call is treated as a separate data stream. If your carrier or plan does not support VoLTE, or if this feature is turned off in the settings (Settings) → SIM-maps and mobile networks → Use VoLTE, when talking, the phone may fall into the 3G/2G, where the waiting mechanism works differently.
It's a similar situation with Wi-Fi Calling, where if you're talking over Wi-Fi, the second call also has to be supported by your carrier in this technology, and in some cases, if you have a poor Wi-Fi signal, the second call may not reach the device.
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The stability of the second call depends on your carrier’s support for VoLTE and your current location.
To diagnose problems with VoLTE, you can temporarily disable this feature in the mobile network settings and check whether a second call will appear in 3G mode. If everything works in 3G, and in 4G it does not, the problem is on the operator side or in network settings.