13
Section 61245207L2-5, Issue 2
61245207L2-5C
6. DSL DEPLOYMENT GUIDELINES
The ADTRAN FT1 DSL system is designed to
provide Fractional 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)
This deployment criteria is summarized in the chart
shown in
Figure 14
.
Recommended maximum local loop loss information
for PIC cable at 70
°
F, 135
Ω
resistive termination, is
provided in
Table 6
.
An approximation for the maximum amount of
wideband noise on a DSL 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 a DSL
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 14. DSL 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)
INVALID DSL CABLE LENGTHS
VALID DSL CABLE LENGTHS
Table 6. Loop Insertion Loss Data
Frequency (Hz)
Maximum Loss (dB)
3000 .................................... 12.0
10,000 .................................... 15.0
50,000 .................................... 25.5
100,000 .................................... 30.0
150,000 .................................... 32.75
200,000 .................................... 35.25
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