Impulse Noise; Variation Of Gain Versus Level; Method 1 - Meridian Nortel 1 Option 11C Technical Reference Manual

Impulse Noise

Variation of gain versus level

Method 1

Impulse noise is defined as noise bursts or spikes that exceed normal peaks of
idle-channel noise. Impulse noise is measured by counting the number of
spikes exceeding a pre-set threshold; it is the number of counts above 55
dBm0 during a five minute interval, under fully loaded busy hour PBX traffic
conditions.
Table 46
Impulse Noise
Time
5 Minutes
The variation of gain verses level (tracking error) measures how closely
changes in input levels causes corresponding changes in output levels.
The tracking error is measured in decibels and is defined as the deviation in
gain or loss through a range of input level relative to the gain or loss at the
reference frequency and level of 0 dBmO.
The two methods of measuring the tracking error are listed below.
When a noise signal as defined in CCITT, recommendation 0.131 is applied
at the input of any interface, the gain versus level deviation at the output
meets the limits set out in Table 47.
Table 47
Variation of gain versus level method 1
Input Level dBm0
-55 to -10
Alternatively, when a sine wave input in the frequency range 700 - 1100 Hz
is applied at the input of any interface, the gain vs level deviation at the output
meets the limits given in Table 48.
Transmission parameters
Level
>55 dBmO
Option 11C and 11C Mini
Page 169 of 544
Counts
0
Gain Variation dB
+/-0.5
Technical Reference Guide