Explainer: why smartphones auto-switch between Wi-Fi and mobile data
Smartphones continuously monitor signal strength, speed, latency and packet delivery to decide in real time whether to use Wi-Fi or mobile data. This automatic switching is designed to prevent dropped calls and buffering, but it can also trigger disruptive mid-session handoffs, such as during a FaceTime call. Common triggers include weak Wi-Fi signals, Wi-Fi networks with no real internet access, and certain device settings.