“Wires-only” VDSL2 Modem Test Plan - NICC

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NICC ND 1436 V1.1.2 (2013-09)
3) Set the line simulator to a loop length of 100m of TP-100 cable with noise injection disabled
(i.e. noise free).
4) Ensure that the CPE has attained synchronisation.
5) Capture the upstream PSD and wideband power and compare against Part C of the BT
ANFP [6].
6) Repeat for 500m and 1300m loop lengths.
Note : the KL0 value of each loop length (required to establish the appropriate mask in Part C of
the ANFP) shall be established by measuring the insertion loss of each loop at 1MHz.
Expected Outcome – If the upstream transmit spectrum complies with the spectrum limits defined
in Part C of the BT ANFP [6] over the various loop lengths tested and the upstream transmit power
does not exceed 14.5dBm then this will be deemed a “Pass”, else the result will be a “Fail”.
C.1.3 AELEM
Description – The CPE modem shall support the alternate electrical length estimation methodology
(AELEM) for estimating the electrical length of the connection between the CPE modem and the
DSLAM (mode ELE-M1) as defined in G.993.2 [3].
Test Procedure – AELEM is not currently supported on the BT NGA platform therefore it not
possible to perform this testing on Live build level network elements. However, an indication of
how well a CPE modem estimates loop length in the presence of bridged taps caused by internal
wiring in a self-install scenario can be obtained using the following test procedure.
Test Description –
1) Configure the DSLAM to implement a CAL value of 30dB and the default band profile.
2) Connect the CPE modem to the DSLAM using the test setup shown in Figure C.3
3) Set the line simulator to a loop length of 500m of TP-100 cable with the appropriate crosstalk
injected at each end of the system. This equates to a kl0 value of ~10dB measured at 1MHz.
4) Ensure that the CPE has attained synchronisation.
7) Wait 2 minutes for the system to stabilise and then record reported kl0 values for each band
(DS1, DS2, DS3, U1, U2 etc.) from EMS.
8) Capture the upstream transmit PSD spectrum.
9) Compare the PSD against the BT ANFP [6] Part C PSD mask for the kl0 value of 10dB.
10) Compare the reported kl0 values for each band with the ranges defined in Table C.2.
11) Repeat this for a 100m loop (kl0 ~ 2dB @ 1MHz).
NICC Standards Limited