Characteristic Analysis On The Cross Talk Of Multiple Pairs Telecommunication Cable

When telecommunication cable is used for the purpose of digital signal transmission, the maximized application of the system very much depends on the cross talk characteristics of the cable. Therefore, it is very important to understand the cross talk characteristics of multiple pairs cable. This paper analyzes the cable cross talk characteristics in terms of inter-pairs cross talk and the importance of statistic of multiple pairs cable cross talk. In one way, respecting the fact of the inter-pairs cross talk of cable, the cross talk is divided into systematic cross talk and random cross talk. The relation formula between the structured sizes of inter-pairs and the coupling vector of systematic cross talk is deduced. By calculating of inter-pairs function, the influence of twist lay of a pair on the systematic cross talk is clearly defined. Secondly, this paper analyzes the major factors which influence on random cross talk, and the way to reduce random cross talk is discussed. In another way, this paper discusses cable multiple pair in respect to statistics. Analysis is made on the average value of the defense power of far-end cross talk and near-end cross talk attenuation value(M-S). By combining YD322, GBT13849 standards and the stipulation of cross talk performance in the network access requirement of YD/T630, this paper discusses in details defense power of far-end cross talk and the calculation between near-end cross talk attenuation and length. Problems which need attention to the calculation of the average value of the defense power far-end cross talk is specially pointed out.