| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce power consumption and to secure efficient radio communication by performing control for changing a transmission power value according to a state of the radio communication. <P>SOLUTION: A wireless LAN module 20 detects C/N ratio to carrier wave received by a C/N detection circuit 21c included in an RF circuit part 21, determines the present level of wireless LAN environment based on the detected C/N ratio, simultaneously determines a transmission power value corresponding to the determined level from a power table 40. A CPU 27 controls a power control part 21a of the RF circuit part 21 so as to perform transmission by the determined power value. Thus, when a state of a wireless LAN is satisfactory, the transmission power value is lowered to reduce the power consumption within a range that a transfer bit rate is not reduced and when the state of the wireless LAN is not satisfactory, the transmission power value is enhanced to maintain predetermined communication efficiency. <P>COPYRIGHT: (C)2008,JPO&INPIT |
