ADC H2TU-C-202 User Manual page 27

LTPH-UM-1072-03
Front-Panel
ADC Config
Display
Menu Options
Code
H2TU-R DS1 Frame CONV
Conversion
See "H2TU-R DS1
Frame Conversion
(CONV) Option" on
page 21.
DS1 Line Coding (DS1) Option. The DS1 line code option should always be set to conform to the type of
DS1 service (AMI or B8ZS) being provided by the HiGain system.
H2TU-C Equalization (EQL) Option. The equalizer shapes the DS1 output signal of the H2TU-C to conform
to a very specific pulse template when it arrives at the DSX-1 cross-connect point. The degree of pulse-shaping
required is a function of the distance between the H2TU-C's equipment bay and the DSX-1 panel. Thus, the
equalizer has six discrete settings, in increments of 133 feet to cause the maximized separation of 655 feet.
Alarm Pattern (ALMP) Option. To improve HiGain HDSL2 compatibility with the switch-to-protect features
used in Digital Loop Carrier (DLC) feeder applications, the H2TU-C-202 List 2F has an ALMP option that allows
you to select either an AIS or LOS DS1 output payload for the following alarms:
• LOSW on any loop
• LOS DS1
Power Back Off (PBON and PBOC) Options. Power Back Off Network (PBON) and Power Back Off
Customer (PBOC) allow the HDSL2 circuit to support two transmit power templates: default (DEF), higher level,
and enhanced (ENH), lower level. These are defined in Section 6.1.4.2 of the ANSI T1E1.4 HDSL2 standard.
Each HDSL2 receiver detects the level it is receiving during the start-up, pre-activation sequence. It then compares
this level to the level it should be receiving according to the PBON and PBOC option settings (DEF or ENH). If
the received level is outside the template limits, the receiver sends a message to the upstream HDSL2 transmitter
requesting the proper level. These levels are adjusted only during the start-up routine or if the PBON or PBOC
option settings are changed during normal operation. Since the ENH template levels are up to 15 dBm below those
of the DEF template, the ENH setting can be used to reduce crosstalk levels into adjacent circuits. (For example,
if crosstalk noise is being induced by the H2TU-R, set the PBOC option to its lower (ENH) level setting.
Conversely, if the HDSL2 signal at the H2TU-R is being affected by crosstalk noise induced from adjacent pairs,
set the PBOC option to its higher (DEF) level setting.
Changing these Power Back Off option settings on a live circuit causes the HDSL2 loop to
momentarily drop and then reacquire synchronization. This setting can also affect the operating
margins.
Bipolar Violation Transparency (BPVT) Option. The H2TU-C-202 List 2F improves compatibility with
the DLC feeder applications because of its ability to transmit DS1 BPV occurrences between its DS1 interfaces.
This feature is required to support protection switching in DLC applications. Each DLC terminal must be able to
monitor the integrity of its Receive DS1 payload and then switch to the protect line when the integrity of the path
drops below specific user selected limits.
An essential requirement is for each DLC terminal to detect BPVs in its DS1 input. Standard HDSL systems
correct DS1 BPVs at the input and, therefore, prevent them from being detected by the DLC terminals to which
they are connected. The H2TU-C-202 List 2F and its associated remote units remove this limitation and become
H2TU-C-202 List 2F
Table 6. H2TU-C-202 ADC Config Menu Options (Continued)
Selection Description
OFF Framing functionally determined by the framing option. Frame format
conversion is inhibited at the H2TU-R.
ACON Auto (ACON) detection of framing and potential frame conversion at the remote.
FCON Auto detection of framing and forced frame format conversion (FCON) at the
H2TU-R.
October 25, 2002
Provisioning
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