Communication terminal device applicable to aerial vehicle and mobile communication method using the same

A communication terminal device applicable to an aerial vehicle and configured to perform wireless communication with a terrestrial mobile communication network, the communication terminal device comprises:

• an antenna configured to provide a transceiving range of electromagnetic waves;
• an altimeter configured to obtain an altitude measurement value adapted to specify a flying height of the aerial vehicle;
• a processing circuit coupled to the antenna and the altimeter and configured to:
• determine whether the altitude measurement value exceeds a height threshold value;
• set the transceiving range of electromagnetic waves of the antenna to be omni-directional in response to determining that the altitude measurement value does not exceed the height threshold value, such that the transceiving range of electromagnetic waves comprises directions above and under a horizontal plane parallel to the Earth's surface;
• and
• execute an antenna beam width adjusting mechanism to shape the transceiving range of electromagnetic waves of the antenna into a beam which is directional in response to determining that the altitude measurement value exceeds the height threshold value, such that the transceiving range of electromagnetic waves only comprises directions under the horizontal plane parallel to the Earth's surface.