Nortel Networks 311

156 NT1R20 Off-Premise Station Analog Line card

•The attenuation distortion (frequency response) of the OPS facility

should 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 ohm cable.

If the OPS line facility loss is greater than 4.5 dB but does not exceed 15

dB, line treatment using a switched-gain voice frequency repeater (VFR)

extends the voice range.

The overall range achievableon an OPS line facility is limited by the

signaling range (2300 ohm loop including telephone set resistance).

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 AWGwire, 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 voicerange to the full limit of the signaling range:

•15 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 por ts in

accordance with the loss plan. This plan determines the port-to-por t 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 valuethat is

ﬁxed forall calls. The loss in the other port involved in the call can vary on a

call-by-call basis to achievethe total loss scheduled by the plan.

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.The totalloss in the facilitybetween the PBX and the

terminal must not exceed 4.5 dB.See Figure91 "NTCK80AA/AB/AC/AD"

(page 338). 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 Economic and

technological changes led to modiﬁcations of these objectives. But

since the loss provisions in the PBX for OPS are constrained by

Nortel Communication Server 1000

Circuit Card Reference

NN43001-311 01.04 Standard

Release 5.0 23 May 2008