“Wires-only” VDSL2 Modem Test Plan - NICC

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NICC ND 1436 V1.1.2 (2013-09)
Test
case
Loop Length
/m (0.5mm)
Loss at
1 MHz / dB
Loss at
6 MHz / dB
AWGN PSD
/ dBm/Hz
1 200 N/A 9.36 -100
2 500 N/A 23.41 -110
3 1000 N/A 46.81 -120
4 2000 36.07 N/A -130
Table B.13 : AWGN Settings for Hlog/QLN Verification (SSFP with no home wiring)
Expected Outcome – This test will be deemed a “Pass” if all of the following conditions are
satisfied:
The Hlog data is recorded over all of the available upstream and downstream bands (ie no
gaps appear in the reported data).
The Hlog data recorded for both upstream and downstream is within 1.5 dB of the model for
a loop of the stated loss, for all frequencies where the received PSD is at least 10 dB above
the noise PSD injected.
The QLN data is within 2dB of the AWGN PSD specified in the test, in the downstream
bands only.
Accompanying template spreadsheets [21], [22] are provided to assist with this evaluation.
Microfilter With Home Wiring – Qualitative Test of Hlog/QLN reporting
Description – This test is defined to test whether a CPE modem interworks with the DSLAMs
sufficiently well to report Hlog and QLN back to the DSLAM in a deployment scenario using microfilters
and home wiring. This data is used for test and diagnostic purposes to reduce time to repair.
The presence of the extension wiring in this case should cause deep nulls to appear in the Hlog
data.
Test Procedure – Configure the noise generator to add AWGN at -110 dBm/Hz at the CPE end of
the simulated loop. Connect the CPE modem to a port on the DSLAM via a 500m length of
simulated 0.5mm gauge cable and a home network as shown in the diagram below. Ensure that
the CPE trains up and reaches synchronisation. Allow one minute to pass for Hlog/QLN data to be
transferred from CPE to DSLAM. Record Hlog/QLN data from the DSLAM element manager.
NICC Standards Limited