PURPOSE: To suppress the reduction of communication quality and system throughput.

CONSTITUTION: When the running speed information of an MBL 11 detected by an SDT 13 is transmitted through an MSI 14 to a CTL 7 as electric signals, an INF 10 receives this information, and an SPP 9 processes the running speed information to be changed with the passage of time and calculates the average moving speed of the MBL 11. A PWC 8 generates data for selecting the class of cells according to whether this average moving speed is higher or lower than a certain threshold value, and these data are transmitted from a TRX 3. Corresponding to the selected cell class, the PWC 8 controls the output power of a TX 5 within a specified range. Therefore, since service is executed while selecting macro-cells or micro-cells corresponding to the moving speed of a moving body, hand-over is not frequently generated in a short time and as the result, the reduction of communication quality and system throughput can be suppressed.