T-BERD/MTS-4000 COPPER SERVICES MODULE
3
Overview of Copper Tests
Today’s copper network requires rigorous testing. The T-BERD/MTS-4000
equipped with Copper Services Modules performs these essential tests and more:
Copper Test
DVOM
Opens
Load Coil
POTS
Balance
Noise
Impulse Noise
Test Function
DSL service qualification and
troubleshooting
DSL service qualification and
troubleshooting
DSL service qualification and
troubleshooting
DSL with POTS service installation
and troubleshooting
DSL service qualification and
troubleshooting
DSL service qualification and
troubleshooting
DSL troubleshooting
What it Tests
DC/AC voltage, loop current, loop
resistance, distance-to-short, leakage
Capacitance, loop length
Presence of load coils and location
Placing a POTS call
Longitudinal balance, Resistive
balance, Capacitive balance
Noise with specific band filters
Voltage spikes above specific thresholds
Why it is Needed
Overall copper health
Cable damage, loop length acceptable
for DSL
Load coils act as low-pass filters and
must be removed
Connectivity to exchange
Robustness against noise
External noise corrupts good data
Intermittent effects that cannot be
corrected by forward error correction
(FEC)
Attenuation of copper cable
Enough margin to sustain data rate in
changing conditions
Impedance mismatch—using multiple
cable types, causes energy to reflect
Impact of multiple broadband services
in the cable
Identify the characteristics of a noise
source to fix the problem
Detect and locate faults such as opens,
shorts, bridged taps, and wet sections
Resistive fault detection and location
Fault Impact
No DSL synchronization or low data rate
The longer the cable, the higher the
attenuation, and the lower the data rate
Load coils prevent DSL service
No POTS
Noise decreases the bits-per-tone
load/data rate
Noise decreases the bits-per-tone
load/data rate
Impulse noise may lead to continuity
errors including IPTV pixilation and data
retransmission
Reduced DSL data rate
Temporary loss of signal or reduced data
rate possible
Reduced data rate
Reduced data rate
Reduced data rate
No sync or reduced data rate
Reduced data rate
Loss
SNR
Return Loss
Near-End Crosstalk (NEXT)
Spectral Analysis
TDR
RFL
DSL service qualification and
troubleshooting
DSL service qualification and
troubleshooting
DSL service qualification and
troubleshooting
DSL troubleshooting
DSL troubleshooting
DSL troubleshooting
DSL troubleshooting
Rx/Tx Tones
Signal compared to noise level
Impedance mismatch
Noise from near-end
Spectral noise per frequency
Impedance anomaly and location
Pair under test against a reference
using ohmmeter
JDSU [ JDS UNIPHASE CORPORATION ]
