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Maintenance Architecture
555-233-123 1-22 Issue 4 May 2002
Table 1-14 lists the quantization distortion loss in the system for analog port to
digital port and digital port to analog port.
Terminating Impedance: 600 Ohms nominal
Trunk balance impedance (selectable): 600 Ohms nominal or complex Z [350 Ohms + (1 k
Ohms in parallel with 0.215uF)]
Impulse Noise
On 95% or more of all connections, the impulse noise is 0 (hits) in five minutes at
+55 dBrnC (decibels above reference noise with C-filter) during the busy hour.
ERL and SFRL Talking State
Echo-Return Loss (ERL) and Single-Frequency Return Loss (SFRL) performance
is usually dominated by termination and/or loop input impedances. The system
provides an acceptable level of echo performance if the ERL and SFRL are met.
Table 1-14. Quantization Distortion Loss
Analog Port-to-Digital Port or Digital Port-to-Analog Port
Signal Level Distortion Loss
0 to -30 dBm0 >35 dB
-40 dBm0 >29 dB
-45 dBm0 >25 dB
Station-to-station ERL should meet or exceed 18 dB
SFRL should meet or exceed 12 dB
Station to 4-wire trunk connection ERL should meet or exceed 24 dB
SFRL should meet or exceed 14 dB
Station to 2-wire trunk connection ERL should meet or exceed 18 dB
SFRL should meet or exceed 12 dB
4-wire to 4-wire trunk connection ERL should meet or exceed 27 dB
SFRL should meet or exceed 20 dB