| The optical fiber transmission techniques have been applied to a wired television transmission network, and replacing the long—distance cable backbone, and application of the co-axial cable advantages as of the transmission medium has formed a concept of Hybrid Fiber Coax(HFC)of the branch and going to-some place by distribution.Frequency band of the wired—television net widths is about 5 to 860MHz, but the wired television network , in a traditional sense , is a unidirectional broadcasting network , but now reforming it into a bi-directional mutual broadcasting network whether in technique or in amount of work, is formidable and difficulty of which lies in the bi-directional mutual reverse transmission.In this paper, about how to realize the wired television bi-directional HFC network technical problems of " the collecting disturbance" and "collecting equalization" were presented because of using the co-axial cable as transmission medium of the branch and going-to-some place by distribution have been solved, and beginning with the noise disturbance analysis, some methods and countermeasures of reforming and settling the problem have been put forward using part of experimental data and theoretic calculation . Utilization of high separation TAP shaving the back-transmission path equalization, and increasing the reversal blocking, adoption of star-connection networkstructure, and improvement of the construction technology and method ofselection of materials cause the back-transmission noise tO be decreasedmagnificently and guarantee there liability of up-going signal.This paper has introduced tile bi—directional HFC network design andarrangement as well as testing and adjusting procedures in detail. At thesametime, this paper has summarized the most important difference between thepositive-direction and back-transmission designs & arrangements forinformation of persons of the same occupation.
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