Abstract
The technology demands the higher speed and low latency network Datacom copper cables which requires compliance of the Alien cross talk. The Power Sum Alien Cross Talk has been introduced to international standards ISO/IEC 11801 Ed. 2.2, ANSI/TIA 568C.2 and it is mandatory parameter for Category 6A and above copper LAN Cables. Alien Crosstalk is the interference caused by a pair of insulated copper conductors in one cable inducing noise into other pairs of insulated conductors in adjacent cables. Power Sum Alien Cross Talk (PSANEXT) is an unwanted disturbing signal transferred from one balanced twisted pair of cable to twisted pair of another cable.
The Alien Cross Talk measurement is time consuming and usually takes 4 hours to prepare testing set up and test. It was demand on us to reduce the time of the measurement and find a correlation between Near End Cross Talk and Alien Cross Talk. In our situation the same cable construction of Cat6a U/UTP was desired and our expectation was to reduce the time to 10 minutes. By reducing the time to 10 minutes we have saved significant amount of financial part for another development. The second factor behind carrying out this correlation study was to avoid the repeated Alien cross talk testing which is a destructive testing in nature. And without more destructive testing we needed to ensure the Alien cross talk compliance in all produced cables.
This study was carried out based on several production trials of cables and tested in 7 cables bunched together where one cable in middle of the bunch was disturbed cable and the remaining surrounding cables were disturbing cables. Detailed test results were recorded and summary of the results prepared. Recorded results were analysed with statistical method. And the co-relation found. Our calculations are showing that we shall achieve Near Cross Talk worst case margins in the range of 2.6 dB to 8.9 dB or higher to get passing Alien Cross Talk ( PSANEXT). It is showing us as the summary that in order to pass Alien Cross Talk we need to have minimum cross talk margin of 2.6 dB.
Keywords: LAN Cable; Alien Crosstalk; Data Copper Cable; Margin; Performance; Correlation; Cat6A; Near End Cross Talk; Power Sum Near End Cross Talk, Power Sum Allen Near End Cross Talk, Attenuation, Power Sum Attenuation to Alien Crosstalk Ratio – Far End.
