| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance convenience for users by restarting a hands-free call while using the other mobile telephone set even when a mobile telephone set that performs call processing is disabled to communicate. <P>SOLUTION: When it is detected the remaining power of a battery in a mobile telephone set 20A that performs a call is lowered to a predetermined value or lower on the basis of remaining battery power information indicating the remaining power of the battery in each of at least a plurality of mobile telephone sets 20A-20N, a hands-free telephone instrument 10 switches the call into a call via the other mobile telephone set wherein the remaining power of the battery is larger than that of the mobile telephone set 20A. Thus, the hands-free telephone instrument 10 uses the new mobile telephone set to restart the hands-free call without requiring a user in driving to temporarily stop the vehicle. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
