150-231-185-05, Revision 05
Provisioning
HLU-231 List 8E
September 13, 1999
23
Equalization Option
Equalization is the configuration of system transmission characteristics within specified limits. An adaptive
equalizer inserts a frequency-shaped loss that corresponds to an equivalent addition of an appropriate cable length.
By simulating the additional cable loss necessary for correct operation, the equalizer compensates for a range of
variation in transmission path characteristics.
BPVT Option
The HLU-231 List 8E improves HiGain’s compatibility with Digital Loop Carrier (DLC) feeder applications
because of its ability to transmit T1 BPV occurrences between its T1 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
T1 payload and then switch to the protected line when the integrity of the path drops below specific user-selected
limits. An essential requirement of this feature is the need for each DLC terminal to detect BPVs in its T1 input.
Standard HDSL systems correct T1 BPVs at the input and therefore prevent them from being detected by the DLC
terminals to which they are connected. The HLU-231 and its associated remote units remove this limitation and
become BPV transparent by detecting and counting input BPVs at each end and then replicating them at the T1
output port of the distant end.
This BPVT option is controlled by the BPVT user option, which allows it to be Enabled (ENA) or Disabled (DIS).
In addition, the CRCs in each direction of every HDSL loop of each span are also counted and added in with the
BPV count to produce a Total Error Count (TEC) that indicates the integrity of both the T1 and HDSL paths. A
TEC in each direction is calculated each second by adding the number of BPVs to the number of HDSL CRCs in
Alarm Pattern
ALMP
AIS
Enables HiGain to output an AIS payload at its DS1 ports for LOSW, T1 LOS
and Margin alarms.
LOS
Enables HiGain to output an LOS condition at its DS1 ports for LOSW, T1 LOS
and Margin alarms.
Remote Provision
RTPV
DIS
Prevents options from being changed at the remote when remotely logged on.
ENA
Allows options to be changed at the remote when remotely logged on.
Bipolar Violation
Transparency
(See
below.)
BPVT
ENA
Enables input DS1 BPVs and HDSL CRC errors to be converted into DS1 BPVs
at the distant end’s DS1 output port. This makes HiGain transparent to BPVs
and enables fast LOSW.
DIS
Disables input DS1 BPVs and HDSLCRC errors from being converted into DS1
BPVs at the distant end’s DS1 output port.
Customer
Disconnect Indicator
CDI
ENA
Enables the HLU to output the special payload patterns that indicate a RLOS
condition.
DIS
Disables the CDI output patterns.
Confirm Settings
CONF
YES
Confirms that all operating modes are to be updated to their current
selections.
NO
Prevents the most recently selected operating mode selections from being
updated. They remain as they were before the system option settings mode
was entered.
When BPVT is enabled in systems with four or less doublers, the response time to an HDSL
LOSW is approximately 70 ms, which gives DLC terminals time to react and avoid dropped calls.
Table 8.
HLU-231 List 8E System Settings (Cont.)
System Settings
Screen Options
Front-panel
Display
Code
Parameter
Description
