Litespan; Applications; Figure 2. Htu-C Span Powering Diagram; Figure 3. Deployments From A Litespan Channel Bank Assembly - ADTRAN AHT1U Installation & Maintenance

2. APPLICATIONS

The ADTRAN HDSL system provides a cost-effective
alternative for deploying T1 service over metallic
cable pairs. In contrast with traditional T1 service
equipment, ADTRAN HDSL can be successfully
deployed over two unconditioned, non-loaded,
bridged-tapped copper pair CSA loops (see subsection
6 of this practice).
Litespan HDSL deployment is typically made from a
Litespan 2000, Litespan 2012, or Litespan ONU
channel bank assembly. Figure 3 shows possible
ADTRAN HDSL deployments from a Litespan
channel bank assembly.
ADTRAN HDSL systems can be deployed quickly
without the use of expensive T1 repeater equipment
on standard CSA loops while using the existing
massive copper-fed twisted line pairs in use by the
industry.
Litespan 2000 or 2012 System with Litespan HTU-C deployment
Common
Control
Channel Bank
Assembly with
a Litespan
HTU-C
Installed
Typical Starspan System
Common
Control
High-Density
Fiber Bank

Figure 3. Deployments from a Litespan Channel Bank Assembly

61245002L6-5C
2B1Q
HDSL

Figure 2. HTU-C Span Powering Diagram

HDSL Loop Pairs
HDT
OLNK
Litespan HTU-C
Section 61245002L6-5, Issue 3
ADTRAN uses negative ground-referenced span
powering voltage (-135 VDC) on HDSL loop 2 while
loop 1 remains at ground. This prevents corrosion
associated with positive ground reference voltage
while providing power for the HTU-R. HTU-R span
powering can be disabled to allow locally-powered
HTU-R applications, if desired.
If normal CSA loops need expanding beyond the
maximum range of an HTU-C/HTU-R HDSL system,
a span-powered HRE can be added to effectively
double the HDSL serving area. Addition of a
span-powered HRE still allows span powering to be
passed through to a span-powered HTU-R, providing
a totally span-powered HDSL system. However,
addition of an HRE adds to the total power
consumption from the Litespan channel bank
assembly and requires recalculation of the power
budget deployment guidelines (see subsection 6).
HRE deployment may limit total Litespan linecard
deployment.
LOOP 1
SPAN POWER
REGULATOR SPAN CURRENT
LOOP 2
HDSL Unit
Remote End
HDSL Loop Pairs
ONU-96 with
an installed
T (3, 71)
R (4, 72)
T1 (5, 73)
R1 (6, 74)
HDSL Unit
Remote End
3