The prototype handset looks like a regular mobile phone, but has a Compact Flash card slot on the back into which the user can plug a networking card for either a WLan or PHS (Personal Handyphone System).
"This is the first in a new style of mobile telephone," said developer Kazuyoshi Kojima of Mitsubishi's silicon devices technology department. "If you want to change the network, you just pull out one card and plug in another," he said.
Coupled with an IP telephony service provider, the phone could, in theory, be used anywhere in the world in which a WLan connection to the Internet is available. Mitsubishi hopes to launch the phone in 2004.