CopperOptics PairGain PG-Flex FCS-718, Руководство пользователя

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Revision 01 May 30, 1997 Section 363-718-104
PG-Flex FCS-718 PairGain Engineering - Plant Series Page 19
6. Pre-Provisioning—HDSL Lines
6.1 The HDSL transmission scheme uses two pairs between the COT and the Remote Terminal (RT).
The wire pairs should have identical electrical make-ups. Keep exposure to crosstalk and the
differences in total wire length, wire gauge, bridge taps to a minimum. Pair isolation (Tip-Ring,
Tip-Ground, and Ring-Ground) must be
≥
100 k
Ω
.
6.2 The wire pairs from the COT to the RT must meet the following design guidelines:
•
nonloaded cable only
•
multi-gauge restricted to two gauge changes, except for stubbing or fusing
•
total bridge taps can not exceed 2.5 kft. No single bridge tap may exceed 2.0 kft
6.3 The distance limitation for HDSL transmission is based on a maximum signal attenuation of 35 dB.
Since signal attenuation decreases as cable size increases, the larger the gauge (i.e., 19 AWG vs.
26 AWG), the greater the distance between the COT and the RT. Tables 17 and 18 identify these
distances (at a cable temperature of 68°F).
Table 17. 12/24 Channel HDSL Transmission Distance
Gauge Loop Length Resistance
19 AWG
0.9 mm
22.8 kft
7.0 km
367
Ω
22 AWG
0.6 mm
16.1 kft
4.9 km
521
Ω
24 AWG
0.5 mm
12.3 kft
3.7 km
638
Ω
26 AWG
0.4 mm
9.0 kft
2.7 km 750
Ω
Table 18. 16/32 Channel HDSL Transmission Distance
Gauge Loop Length Resistance
19 AWG
0.9 mm
19.4 kft
5.9 km
312
Ω
22 AWG
0.6 mm
13.7 kft
4.2 km
444
Ω
24 AWG
0.5 mm
10.7 kft
3.3 km
554
Ω
26 AWG
0.4 mm
8.1 kft
2.5 km 672
Ω