ADTRAN 1247026L1, Installation And Maintenance Manual

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Menu Descriptions
61247026L1-5A 19
A measure of signal quality for each HDSL loop appears on the bottom right and left of the
screen. Guidelines for interpreting the measure indicators are given in
Table 12 .
Predicting performance based upon signal quality varies with each loop. Generally, a noise
margin of 0 or higher supports a bit error rate of 10
-7 or better. ADTRAN defined guidelines that
correspond to the operation of the T200 HTU-R, SP/60 mA front panel LEDs labeled
DSL1
and
DSL2
are illustrated in Table 13 .
Table 12. HDSL Loop Signal Quality
Measure Signal Quality Noise Margin
0 Poor
≤
0 dB (
≈
10 –7 BER)
1-3 Marginal
above 10 –7 BER in dB
≥
4 Excellent ≥
4 dB above 10 –7 BER
Table 13. ADTRAN Noise Margin Guidelines
Margin LP1/LP2 LED Loop Quality
Margin = 0
z
Red Poor Loop Quality
0 < Margin < 4
z
Yellow Marginal Loop Quality
Margin > 4
z
Green Good Loop Quality