Mobile communication terminal and transmission power controlling method

The present invention aims to make a disconnection of communications less likely to occur even in a rapidly changing wireless communication environment. To this end, a mobile communication terminal is provided. The provided terminal includes a transmission power controller configured to measure a reception SIR, and to control a transmission power of a base station in accordance with a result of comparison between the reception SIR and a target SIR. The terminal also includes a target value updater configured to measure a reception BLER, and to update a target SIR in accordance with a measurement result. In addition, the terminal includes a measurement controller configured to acquire a moving state of the terminal to which the measurement controller belongs, and to control a period of measuring the reception BLER and control a cycle of updating the target SIR.