Nokia has started its first tests of a technology that allows users to roam seamlessly between phone networks and local wireless hotspots such as Wi-Fi. Fifty families in Oulu near the polar circle in northern Finland will test the technology over the next two months. Mobile subscribers with handsets enabled for so-called unlicensed mobile access, or UMA, can make calls over the Internet when they are in range of an unlicensed wireless network such as Bluetooth or Wi-Fi.