Longitudinal Balance; Crosstalk - Meridian Nortel 1 Option 11C Technical Reference Manual

Page 174 of 544

Longitudinal balance

Crosstalk

553-3011-100 Standard 14.00
Transmission parameters
Longitudinal balance defines the amount of impedance balance that exists
between the tip and ring conductor with respect to ground. Longitudinal
balance is measured by injecting a longitudinal signal on the tip and ring
conductors with respect to ground and measuring the amount of signal (noise)
that is introduced between the tip and ring. The equation for calculating
longitudinal balance is:
Longitudinal Balance = 20 Log Vs/Vm
Vs is the disturbing longitudinal voltage and Vm is the tip to ring metallic
noise voltage. Ideally the metallic noise voltage would be negligible and the
longitudinal balance would approach infinity.
Table 54
Longitudinal balance for loop start interfaces
Frequency
Hz
200
500
1000
3000
Crosstalk is speech signal (signalling) energy transferred from one voice
channel to another. The crosstalk coupling loss for every possible type of
connections over the frequency range of 200 to 3200 Hz is shown in Table 55.
January 2002
Minimum balance
dB
58
58
58
53
Average balance
dB
63
63
63
58