ADTRAN 3192 H4TU-C, Установка и эксплуатация

Страница: 19 / 30

61223404L2-5A Issue 1, December 2003 19
6. HDSL4 DEPLOYMENT GUIDELINES
The different segments of an HDSL4 circuit are defined
in
Figure 27 .
Figure 27. HDSL4 Circuit Segments
The ADTRAN HDSL4 system provides DS1-based
services over loops designed to comply with the guide-
lines given below. These guidelines apply to the
following circuit configurations:
• a single segment or an HDSL4 circuit with no
H4Rs,
• a circuit having two segments (with one H4R), or
• a circuit having three segments (with two H4Rs).
The guidelines reflected herein are for worst-case
scenarios, that is, for loops that contain a maximum
amount of disturbers, noise, etc.
Actual deployment guidelines can vary based on local
policy. Refer to the guidelines to ensure optimum
performance.
Designing a circuit with loop attenuation greater than
the recommended maximum loss may result in compro-
mised reliability of that loop. Follow the guidelines in
in this section to ensure that the circuit meets basic
requirements:
1. All loops are nonloaded only.
2. Any single bridged tap is limited to 2 kft.
3. Total bridged tap length is limited to 2.5 kft.
4. Bridge tap within 1000 feet of units may affect
performance of the circuit.
5. Loop Attenuation Limits. See Table 6 .
6. DSL-Recommended Range Limits. See Table 7
and Table 8 .
NOTE
In three segment circuits (two H4Rs),
individual segment resistance values
must be
verified .
Table 6. Attenuation Limits
Recommended Maximum
Upstream Downstream
1
st
segment
30 dB 32 dB
2
nd
and 3
rd
segment
28 dB 28 dB
Table 7. Range Limits: 26 Gauge / 70°F / PIC
26 Gauge Recommended Maximum
1
st
segment
10,470 ft.
2
nd
segment
9,865 ft.
3
rd
segment
9,865 ft. (see note above)
Table 8. Range Limits: 24 Gauge / 70°F / PIC
26 Gauge Recommended Maximum
1
st
segment
14,770 ft.
2
nd
segment
14,050 ft.
3
rd
segment
14,050 ft. (see note above)