Center communications control device of frequency Agile device and CATV communication system, frequency Agile control manner, and CATV communication system

摘要

PROBLEM TO BE SOLVED: To provide a frequency agile device, a center communication controller of a CATV communication system, and a frequency agile control method which actualize the speedy start of operation after frequency variation at low cost. ;SOLUTION: When an up signal reception part of a center communication device of a CATV communication system monitors noise level in an up frequency band in operation and decides that the noise level disables the operation, the frequency agile device varies the frequency to a previously specified frequency, and the device is equipped with a means, which investigate the noise state for a certain time after the frequency of the up signal reception part, is varied and a means which prepares plural agile variation-destination frequencies, scans the frequencies in the order, if it is found that the operation is impossible by investigating the noise state, and returns to the original frequency, after certain time of operation or scanning with the agile destination frequencies.;COPYRIGHT: (C)2001,JPO