ADTRAN T200 H2TU-R, Руководство по установке и обслуживанию

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17 61222026L1-5, Issue 1 61222026L1-5A
6. HDSL2 DEPLOYMENT GUIDELINES
The ADTRAN HDSL2 system is designed to provide
DS1-based services over loops designed to comply
with Carrier Service Area (CSA) guidelines. CSA
deployment guidelines are given below.
1. All loops are non-loaded only.
2. For loops with 26-AWG cable, the maximum
loop length including bridged tap lengths is 9
kft.
3. For loops with 24-AWG cable, the maximum
loop length including bridged tap lengths is
12 kft.
4. Any single bridged tap is limited to 2 kft.
5. Total bridged tap length is limited to 2.5 kft.
6. The total length of multi-gauge cable containing
26-AWG cable must not exceed
12 - {(3*L
26
)/(9-L
BTAP
)} (in kft)
L
26
=Total length of 26-AWG cable
excluding bridged taps (in kft)
L
BTAP
=Total length of all bridged taps (in kft)
For more information regarding deployment
guidelines and applications, reference ADTRAN’s
Supplemental Deployment Information for HDSL/
HDSL2
, P/N 61221HDSLL1-10
This deployment criteria is summarized in the chart
shown in
Figure 21 . Loop loss per kft for other wire
is summarized in Table 6 .
Recommended maximum local loop loss information
for PIC cable at 70
°
F, 135
Ω
, resistive termination is
provided in Table 7 .
An approximation for the maximum amount of
wideband noise on an HDSL2 local loop as measured
by a 50 kb filter is
≤
31 dBrn.
An approximation for the maximum level of impulse
noise as measured using a 50 kb filter on an HDSL2
loop is
≤
50 dBrn.
NOTE
These approximations are to be used as guidelines
only and may vary slightly on different loops.
Adhering to the guidelines should produce
performance in excess of 10
-7 BER.
26 .......... PIC ............ 3.902 .......... 4.051 ....... 4.253
26 .......... Pulp ........... 4.030 .......... 4.179 ....... 4.381
24 .......... PIC ............ 2.863 .......... 2.957 ....... 3.083
24 .......... Pulp ........... 3.159 .......... 3.257 ....... 3.391
22 .......... PIC ............ 2.198 .......... 2.255 ....... 2.333
22 .......... Pulp ........... 2.483 .......... 2.45 ......... 2.629
19 .......... PIC ............ 1.551 .......... 1.587 ....... 1.634
19 .......... Pulp ........... 1.817 .......... 1.856 ....... 1.909
Cable Cable Temperature
Gauge Type 68
°
90
°
120
°
Table 6. HDSL2 Loss Values
(200 kHz cable loss in dB/kft at 135
Ω
)
3,000 ............................................. 12.00
10,000 ............................................. 15.00
50,000 ............................................. 25.50
100,000 ............................................. 30.00
150,000 ............................................. 32.75
200,000 ............................................. 35.25
250,000 ............................................. 37.50
325,000 ............................................. 42.00
Frequency (Hz) Maximum Loss (dB)
Table 7. Loop Insertion Loss Data
Figure 21. Deployment Guidelines
0
12
11
10
9
8
7
6
5
4
3
2
1
0
1 2 3 4
WORKING LENGTH OF 26 GAUGE CABLE (KFT)
WORKING LENGTH OF 24 GAUGE (OR COARSER) CABLE (KFT)
5 6 7 8 9
2.5
2.0
1.5
1.0
0.5
0.0
TOTAL
BRIDGED
TAP
LENGTH
(KFT)
VALID CABLE LENGTHS
INVALID CABLE LENGTHS