Bad call reception at home? A new mobile service allows you to seamlessly place calls on both your cellular network and on any open Wi-Fi hotspot

Cellphones, which are supposed to let you call from anywhere, often work worst in your own home; signals can´t penetrate walls as well as they travel urban canyons and the great outdoors. But T-Mobile is hoping to change that, rolling out a service today that allows users to hop on their home Wi-Fi network or any other hotspot to make calls when cell signals are weak.