154 NT1R20 Off-Premise Station Analog Line card
15.0dB (loss corresponding to the maximum signaling range)
–4.5 dB (OPSservice loss objective)
=10.5dB (required gain treatment)
The use of dial long line units to extend signaling range of OPS analog line
cards beyond 15 dB is not recommended.
Loss is inserted between OPS analog line card ports and other Meridian
1 ports in accordance with the Meridian 1 loss plan. This plan determines
the port-to-port loss for each call.
When a port is configured for CLS OPS, loss is programmed into the OPS
analog line card on a call-by-call basis. When configured for CLS ONS, an
OPS analog line card port is programmed to a value that is fixed for all calls.
The loss in the other port involved in the call can vary on a call-by-call basis
to achieve the total loss scheduled bythe plan. Transmission Parameters
Reference (NN43001-282) shows the specific loss for each possible
port-to-port combination.
For satisfactory transmission performance, particularly on connections
between the public network and an OPS termination, it is recommended
that facilities conform to the following:
•Total1 kHz loss from the local ser ving CO to the OPS terminal should
not exceed 7.0 dB.Of that total, the loss in the facility between the PBX
and the terminal should not exceed 4.5 dB. See Figure 25 "Traditional
OPS application configuration" (page 149).
The following requirements are based on historic Inserted Connection
Loss (ICL) objectives:
— PBX – CO trunk: 5 dB with gain; 0–4.0 dB without gain
— OPS line: 4.0 dB with gain; 0–4.5 dB without gain
In recent times economic and technological considerations led to
modifications of these historic objectives. However, the loss provisions
in the PBX for OPS are constrained by regulatory requirements as well
as industry standards; they are not designed to compensate for modified
ICL designs in the connecting facilities.
•Nortel Networks recommends that the attenuation distortion (frequency
response) of the OPS facility be within ±3.0 dB over the frequency
range from 300 to 3000 Hz. It is desirable that this bandwidth extend
from 200 to 3200 Hz.
•The terminating impedance of the facility at the OPS port should
approximate that of 600 ohms cable.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright© 2003-2008, Nor tel Networks
.