Nortel Networks 1000 - Manual (Page 143)

Application 143
The overall range achievable on an OPS line facility is limited by the
signaling range (2300 ohms loop including telephone resistance). The
signaling range is unaffected by gain treatment;so gain treatment can be
used to extend the voice range to the limit of the signaling range. For
example, on 26 AWG wire, the signaling range of 2300 ohms corresponds
to an untreated metallic loop loss of 15 dB. Gain treatment (such as a
VFR) with 10.5 dB of gain would maintain the OPS service loss objective
of 4.5 dB while extending the voice range to the full limit of the signaling
range.
15.0
dB
(loss corresponding to the maximum signaling range)
– 4.5 dB (OPS service loss objective)
= 10.5
dB
(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 by the 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:
•
Total 1 kHz loss from the local serving 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 24
"Traditional OPS application configuration" (page 138) .
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
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.