Success story: Alien crosstalk measurement

More and more computers populate our offices nowadays and their communication speed increases steadily. This leads to a dramatic multiplication of data cables in our buildings which can disturb each other by electromagnetic coupling. Indeed for long times, the performance of the cable was related to their resilience against disturbance between the pairs of the cable. It appears that it must now be characterised with a new set of parameters, introduced in the standards as Alien Crosstalk, consisting in measuring the influence of six four pairs so called disturber cables surrounding a central victim cable. Those parameter need to be measure up to 500MHz according to the standard ANSI/TIA-568-C.2

Issue

Most of the equipment available on the market are for 25 pairs. However, measuring Alien Crosstalk requests connecting 28 pairs! The industry had to go around the problem by implementing different emergency tricks like multi-loading or merging results through Excel spreadsheet. All of them were subject to errors and very greedy of time and resources both in personnel and equipment. A full characterisation was requesting more than ten hours to complete.

AESA solution

It was decide to conceive a new test system dedicated to this Alien Crosstalk characterisation. Two different technologies were implemented, one with Radiall coaxial relays, the other with solid state switching. The Vega 1028 respectively 7528 allow now performing the full characterisation of a seven four pairs cables bundle in less than twenty minutes, cables preparation included. The effectiveness is overwhelming.

 

 

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