| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a narrow-band communication device capable of performing communication by taking out outside a mobile unit. <P>SOLUTION: A power supply monitoring section 104 monitors the supply of power from a vehicle-mounted battery 200, and passes the information to a control unit 110 in succession or in the change of a power supply. At the control unit 110, when it is determined that the supply of power from a vehicle 200 is stopped, it is not necessary to select a frequency at a high speed since it is considered that mostly narrow-band communication (DSRC) is utilized at the passing speed of the degree of walking, not by high-speed travelling, when the narrow-band communication is used outside the vehicle. Additionally, since it is considered that no problems are presented even if an interval in frequency scan is lengthened, for example, the interval in the frequency scan is lengthened by the degree of several tens to several hundreds times larger than the case when power is supplied to a radio communication section 105 and transmission output is decreased. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
