ADTRAN 3192 H2TU-C, Руководство по установке и обслуживанию

Страница: 17 / 24

61222004L2-5A Section 61222004L2-5, Issue 1 17
6. HDSL2 DEPLOYMENT GUIDELINES
The ADTRAN HDSL2 system provides DS1-based
services over loops designed to comply with the
Carrier Service Area (CSA) guidelines 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 the following:
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)
This deployment criteria is summarized in
Figure 22
.
Table 6. HDSL2 Loss Values
(200 kHz cable loss in dB/kft at 135
Ω
)
Cable Cable Temperature
Gauge Type 68
°
90
°
120
°
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
Table 7. Loop Insertion Loss Data
Frequency (Hz) Maximum Loss (dB)
3,000 ....................................... 12.0
10,000 ....................................... 15.0
50,000 ....................................... 25.5
100,000 ....................................... 30.0
150,000 ....................................... 32.75
200,000 ....................................... 35.25
250,000 ....................................... 37.50
325,000 ....................................... 42.00
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 kbps filter is
≤
31 dBrn.
An approximation for the maximum level of impulse
noise as measured using a 50 kbps 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.
Figure 22. HDSL2 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
INVALID HDSL2 CABLE LENGTHS
1.5
1.0
0.5
TOTAL
BRIDGED
TAP
LENGTH
(KFT)
VALID HDSL2 CABLE LENGTHS
2.0
0.0
For more information regarding deployment
guidelines and applications, reference ADTRAN’s
Supplemental Deployment Information for HDSL/
HDSL2
, P/N 61221HDSLL1-10.