Nokia and Motorola have unveiled phones capable of switching between cellular coverage outdoors and cheap wireless Internet calling indoors using a single number, an Associated Press report said.
Nokia unveiled the Nokia 6136, while Motorola introduced its A910 handsets at the 3GSM World Congress in Barcelona, the report said.
The report said the handsets could connect to the Internet via Wi-Fi, rather than Bluetooth, to make cut-price calls from the home, office or public hotspot.
The report added that mobile networks were keen on joining Nokia and Motorola.
BT Group had already begun shipping Motorola handsets to the first customers of its BT Fusion service, the first in the world to allow users to switch in mid-call between cellular and VoIP, delivered via a Bluetooth wireless connection at home, the report said.