| 摘要 |
PROBLEM TO BE SOLVED: To respond quickly by keeping a call state at an emergency. SOLUTION: When a master handset, for example, falls off or is disconnected during establishment of a handset call using the master handset 202 of a living room master unit 2, a changeover is made to at least one of hands-free calls from among hands-free calls by a master microphone 200 and a master speaker 201, and hands-free calls using external call equipment 3, 4, 5, 6 connected to a dwelling unit adaptor 7 while continuing a clocking operation of prescribed call time from the start of a handset call of a mater timer 207. A changeover to at least one of hands-free calls is also made from among hands-free calls using the external communication equipment connected to the dwelling unit adaptor 7 while an adaptor timer 703 continues the clocking operation of the master time 207 when a disconnection or the like occurs in a transmission line L10 for connecting the living room master unit 2 to the dwelling unit adaptor 7 during the establishment of the handset call. COPYRIGHT: (C)2011,JPO&INPIT |
