Alien Crosstalk (AXT) refers to electromagnetic noise generated when multiple cables are bundled together or when ports are closely stacked. In simple terms, it is the noise coupling from adjacent cables onto the cable pair being tested.

Before performing an Alien Crosstalk test, you must use a Fluke DSX Series Cable Analyzer (DSX2-8000 CH or DSX2-5000 CH) to run automatic tests on every cable in the bundle. The automatic test will determine whether each cable can support the IEEE 802.3 10GBASE-T standard. It also measures the insertion loss required by the AxTalk Analyzer to calculate the PS ANEXT and PS AACR-F pass/fail limits.

In addition, the AxTalk Analyzer allows you to select the victim links and disturber links directly from the LinkWare database. The Alien Crosstalk test focuses on two key parameters: PS ANEXT and PS AACR-F.

1. PS ANEXT (Power Sum Alien Near-End Crosstalk) Test

The PS ANEXT test measures the amount of signal that a pair in one cable receives from a near-end transmitter in another adjacent cable. The AxTalk Analyzer measures Alien Near-End Crosstalk across all 16 pair combinations between two cabling links within the 1–500 MHz frequency range.

2. PS AACR-F (Power Sum Alien Attenuation-to-Crosstalk Ratio, Far-End) Test

The PS AACR-F test measures the amount of signal received by a pair in another cable at the far end from a near-end transmitter. The AxTalk Analyzer measures the Alien Far-End Crosstalk attenuation across all 16 pair combinations between two cabling links within the 1–500 MHz frequency range.

If a separate cable for a synchronized link cannot be found, you can perform the test using a channel adapter at the near end, as shown in the diagram.

To complete the process, the AxTalk Analyzer software must be installed on your computer.

That’s the Alien Crosstalk testing procedure for the Fluke DSX2-5000 CH and DSX2-8000 CH Cable Analyzers.
Now, do you think you’ve got the hang of it?