To effectively use an antenna radiation characteristic in both communication modes of telephone calling and data communication.
A method of selecting a transmission antenna for a portable telephone set comprises: a communication mode discrimination step for discriminating whether the communication mode is a voice call or data communication mode; a data communication command step for commanding so that a data path is to be a path for data communication when the communication mode is the data communication mode; a data communicating antenna selection step for selecting an antenna suitable for data communication between a plurality of antennas 2 and 3; a voice call command step for commanding so that the data path will to be a path for voice call when the communication mode is the voice call mode; and a voice call antenna selection step for selecting an antenna 3 suitable for voice call between the plurality of antennas 2 and 3.
Kawai Nobuaki
Yasuhisa Tanizawa