| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a head end for a CATV for sending out a high-quality digital broadcast to the CATV to be able to supply stable signals that makes no digital tuner freeze depending on states of radio waves at the time of receiving a broadcast. <P>SOLUTION: The head end is equipped with a switching means capable of performing selectively switching control of whether received signals from an antenna are allowed to pass or not, a reception monitoring means for monitoring a state of received signals from the antenna and besides producing state monitoring signals corresponding to the sate of the received signals, and a controlling means for receiving the state monitoring signals output from the reception monitoring means to produce control signals for performing the switching control of the switching means. The controlling means compares a predetermined reference value of the state monitoring signals preset in the controlling means with the state monitoring signals output from the reception monitoring means and judges the result compared. The controlling means produces the control signals for controlling the switching means on the basis of the result to perform the switching control by the control signals. <P>COPYRIGHT: (C)2007,JPO&INPIT |
