| 摘要 |
PROBLEM TO BE SOLVED: To detect presence of connection to an SLT or a connection state of a telephone line such as a broken telephone line and to inform a network manager of the detected result without changing a circuit configuration of a conventional radio fixed terminal. SOLUTION: The terminal is provided with a radio section 19 that sends/ receives a radio wave to/from a radio base station, a ringer drive circuit 15 that outputs a ringer signal to an SLT, a hooking detection circuit 17 that detects hooking of the SLT, a constant current circuit 14 that supplies a constant current to the SLT, and a speech circuit 13 that converts a telephone line of the SLT into a transmission reception line of the radio section, the ringer drive circuit outputs the ringer signal with a frequency band at which the SLT cannot ring a ringer to the SLT, the hooking detection circuit detects a reflected ringer signal from the SLT and when the reflected ringer signal is detected for an optional threshold number of times or more, the connection state in response to the SLT and the threshold number of times of the telephone line is discriminated. |
