Page 168 of 544 Transmission parameters
553-3011-100 Standard 14.00 January 2002
Idle Channel Noise
Idle channel noise is noise in the absence of a signal. It is the short-term
average absolute noise power, measured with either C-message weighting for
µ−Law or Psophometric weighting for a A-Law. The 3 k Hz flat measurement
uses equal weighting for all frequencies in the 20-3000 Hz range. The values
are shown in Table 45.
Table 44
Transhybrid loss
Input Frequency (Hz) Transhybrid Return Loss (dB)
300 16
500 20
2500 20
3400 16
Table 45
Idle Channel Noise
Connection
µ-Law C Message
Noise dBrnC0
A-Law Psophometric
dBmP0
3 kHz
dBm0
Line — Line <20 >65 <29
Line — Trunk <20 >65 <29
Trunk — Trunk <20 >65 <29