| 摘要 |
PROBLEM TO BE SOLVED: To quickly recover a fault by adopting a method that simply and easily locates a noise intrusion position. SOLUTION: This system adopts a method that locates a noise intrusion position in a CATV system having an incoming channel and an outgoing channel. Channel converters (B1-Bn) that send check data from a downstream at an end of a transmission line E toward an upper-stream at which a head end is placed through a 1<st> incoming channel, receive the check data and convert the frequency and send the converted data to a 2<nd> incoming channel are placed at many positions on the transmission line. Any of the channel converters is sequentially selected by a command from a center device A and the check data received by the selected channel converter only are outputted to the 2<nd> incoming channel. The center device A locates the noise intrusion position based on the reception state of the received check data in the 2<nd> incoming channel and the position of the selected channel converter. |
