A portable communication device is provided. A communication connection is established with a first external device. A telephone call function using is deactivated, based at least in part on a determination that the portable communication device is communicatively coupled with the first external device and that a cellular communication circuitry of the first external device is available. While the telephone call function is deactivated, a telephone call is performed with respect to a second external device using the communication connection and a cellular communication between the first external device and the second external device. The cellular communication is established via the cellular communication circuitry of the first external device.