Citel EXTender 1000 User manual

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Copyright 2007 Citel plc All Rights Reserved
EXTender 1000U Dedicated Analog Line Specifications
This document provides any customer or service provider with the
necessary specification information to provide dedicated line facilities to the
EXTender 1000U.
Recommended Line Specification:
•Two wire private circuit
•No signaling provisions
•600 Ohm interface
•Sealing current recommended
•For short haul circuits and campus cable, no conditioning
•For longer circuits (longer than 3 miles), recommend C1 or D1 conditioning
at a power level of -12 dBm
•PCM provision hould be lear channel 64 kilobit/s or robbed-bit signaling 56
kilobit/s channel
•NO ADPCM
Technical Information:
1000 Hz Loss Range (Min/Max)
3dB to 20dB loss end-to-end at 1004 Hz
Frequency Response Template
Attenuation distortion relative to 1004 Hz level:
0 to 16dB from 150 Hz thru 200 Hz
0 to 12 dB from 200 Hz thru 300 Hz
0 to 9 dB from 300 Hz thru 400 Hz
0 to 6 dB from 400 Hz thru 500 Hz
0 to 3 dB from 500 Hz thru 600 Hz
0 to 1 dB from 600 Hz thru 1200 Hz
0 to 3 dB from 1200 Hz thru 1800 Hz
0 to 6 dB from 1800 Hz thru 2100 Hz
0 to 9 dB from 2100 Hz thru 2500 Hz
0 to 12 dB from 2500 Hz thru 2800 Hz
0 to 16 dB from 2800 Hz thru 3700 Hz
When plotted on a semi-log graph, the plot should be a smooth U-Shaped curve.

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Copyright 2007 Citel plc All Rights Reserved
Maximum Attenuation Distortion (Slope)
Relative to 1004 Hz, the 404 Hz slope loss shall be no more the 6 dB
Relative to 1004 Hz, the 2804 Hz slope loss shall be no more than 12 dB
Maximum Facility Delay
Propagation delay shall not exceed 2000 milliseconds. Envelope distortion delay
shall not exceed 1.6 milliseconds at any frequency in the range 150-3700 Hz.
Loaded/Non-Loaded Facility Recommendation
Unloaded facilities are recommended. Loaded facilities can be used, but at the
risk of lower performance levels.
Bridge Taps
Bridge Taps are permitted as long as there are no half-taps (only one wire or pair
connected) and that un-terminated bridge taps do not include dual or quad
segments, either buried or in aerial configurations. Long bridge taps (in excess of
6000 cable feet) should be avoided. Multiple bridge taps in a single loop should
also be avoided. The effect of short bridge taps (1500 cable feet) is not significant.
Dry Loops or Sealing Current Recommendations
The MCKAnalog EXTender 1000U works fine with or without a sealing current
(battery).
Other Requirements
•SNR 200-3700 Hz (measured using 1004 Hz pilot tone at -10 dBm) should
be 35 dB or better.
•60 Hz power line component should be at or below 50 dBRN (decibels to
Reference Noise) or -40 dBm.
•Third-harmonic power line noise should be at or below 30 dBRN or -60
dBm.
•IMD (using 4-tone testing method in IEEE 743) should be 45 dB or better
for both second-order and third-order intermodulation distortion.
•Return loss should exceed 30 dB when the remote end of the line is
terminated with 600 ohms.

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Copyright 2007 Citel plc All Rights Reserved
When to use 2 Wire Circuits Instead of 4 Wire Circuits
There are good reasons NOT to convert to two-wire at the customer premise. The
modems you use inside the 1000U Analog EXTender are V.34 modems, and the
modems are "optimized" for use on a loop of around 2,000 feet. Having the 4-wire-
to-2-wire conversion done at the central office means that the modem's echo
cancellers will always have echo to cancel, and thus will operate in the "normal
part" of their operating curves.
With longer loops (say, six miles) it's more optimal to run four-wire to the customer
premise. This is especially true if there is going to be equalization applied to the
line, because it's much easier to equalize a four-wire loop than a two-wire loop.
There is a maintenance reason to prefer a two-wire local loop: when a loop is
broken in a four- wire circuit, it is very difficult to determine what happened. When
you eliminate the only loop, it is simpler to isolate and determine what has
happened. The use of a single loop also means that performance problems will be
seen by both ends, and not just by one end. Because the vast majority of the
problems encountered with leased lines are in the final mile and not in the trunking,
this provides a better maintenance capability.
For Further Assistance, Please Contact Citel Technical Support @ 1-877-248-3587