The MobileSTICK USB device can be plugged into a desktop or laptop computer with an internet connection. It then launches the softphone, with the user’s regular SIM card user to authenticate it on his or her mobile network, whereupon the software enables phone calls, SMS, and MMS messages from the PC, while the user’s existing mobile phone remains active on the same SIM.

The offering uses the AngelIC USB memory stick from Oberthur with an embedded USIM release 6 SIM card, the SIP softphone from CounterPath and, on the back end, the NomadicONE Network Convergence Gateway software from Chicago, Illinois-based BridgePort, which is located in the carrier’s network and sits on an IBM BladeCenter T server.

The three companies said the device allows mobile operators to offer flat rate voice and messaging services to PC users. They said it will underscore services aimed at home office workers, frequent international travelers, and other mobile professionals.

The USB stick will be showcased at this week’s 3GSM World Congress in Barcelona.