“Wires-only” VDSL2 Modem Test Plan - NICC

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NICC ND 1436 V1.1.2 (2013-09)
Annex A (normative):
Generic Test Methods
NOTE : Where the test methods refer to a DSLAM, the DSLAM should be of a type specified by
the relevant ANO for which compliance is intended to be demonstrated.
A.1 Bit swap
Compliance shall be determined by the following test :
Noise Generator/
Injector
Function
Generator
DSLAM
Line Simulator
CPE
PC
PC
Figure A.1 : Test Configuration for Checking Bit Swap
1) Configure the DSLAM to implement an ESEL value of 30dB and the operator-specific band
profile.
1) Connect the CPE modem to the DSLAM using the Test Configuration shown in Figure A.1.
2) Set the line simulator to a loop length of 500m of TP-100 cable with ANO-specific crosstalk
injected at each end of the system.
3) Ensure that the CPE modem has attained synchronisation.
4) Capture bit allocation tables (both upstream and downstream) from the DSLAM element
manager.
5) Inject a narrow band RFI source using the function generator – this simulates a broadcast
AM transmission. Set the frequency to 3MHz and set the power at -50dBm and increase over 1
minute to -20dBm in 2dB steps.
6) Recapture the bit allocation table (both upstream and downstream) from the element
manager.
7) Compare both bit allocation tables.
8) Repeat for a 10MHz tone.
9) If bit swap is implemented then there should be differences between the two sets of bit
allocation table captured from steps 5 and 7, especially around the frequencies used for the RF
tones.
10) The system should not retrain during this test.
NICC Standards Limited