I am writing to bring to your attention an issue I have observed on Samsung dual SIM smartphones regarding mobile data behavior during incoming voice calls on the secondary SIM.
When mobile data is set to SIM 1 and I am actively using an internet-based application, if a regular voice call is received on SIM 2, the data connection on SIM 1 gets interrupted immediately — till the call on SIM 2 is answered. The data session resumes only after the call on SIM 2 is received or is rejected.
This behavior causes noticeable inconvenience, especially when using real-time apps such as online banking, video calls, or navigation.
I have noticed that other Android smartphone brands (such as Motorola, Oppo, Vivo, and Xiaomi) do not exhibit this issue — their mobile data connection remains stable and continuous and immediately switches to SIM 2 the moment the phone on SIM 2 starts ringing. Kindly investigate this matter and provide a software update or configuration fix to ensure uninterrupted mobile data connectivity.
As per your query, we want to inform you that this is the concept with dual SIM phones, where you can see the data on both SIM cards, but you can only use the internet on one SIM at a time on which you are using for calls. Moreover, we have noted down your valuable feedback. will help us to make our services better in future.
I am following up on my previous feedback regarding mobile data behavior on Dual SIM Dual Standby (DSDS) devices, specifically the Samsung Galaxy A54 running the latest One UI version.
While I understand the hardware limitations of a single radio architecture, my observation confirms that the issue stems from a software logic choice regarding when the data handover occurs.
The Specific Technical Issue:
Currently, Samsung’s "Auto Data Switching" feature appears to trigger the data handover only after the call enters the "Off-Hook" (Answered) state. This creates a data blackout during the entire "Alerting" (Ringing) phase.
Comparison with Competitor Implementation:
I have verified that devices from Apple (iPhone 16 Pro/iOS 18) and Google (Pixel series) handle this differently. These devices initiate the data handover immediately upon the "paging" signal (the moment the phone starts ringing). They do not wait for the user to answer the call to switch the data path to the secondary SIM. This ensures the internet connection remains alive for background tasks even while the phone is ringing.
