ADC HiGain H2TU-C-388 List 7F Manual page 29

LTPH-UM-1214-02
HDSL2 Block Error Rate Threshold (HBER) Option. The HBER option permits the monitoring of loop
integrity and reporting of alarms when excessive errors are detected. The PM primitive used for this purpose is
the CRC checksum performed on the HDSL2 frame for both directions of transmission. It is, therefore, called a
block error rate rather than the bit error rate associated with the DS1 interface. The CRC errors and counts are
displayed on the Monitor screen for both the H2TU-C and H2TU-R. The HBER option allows an alarm to be
generated if the total number of CRC errors at either the H2TU-C or H2TU-R exceeds the selected HBER
threshold during the last 1-minute interval.
•
HBER option = 1E-6. Alarm is generated if CRC errors > 93
•
HBER option = 1E-7. Alarm is generated if CRC errors > 9
Once initiated, the HBER count clears when the CRC error count drops below the selected threshold. Selecting
NONE inhibits this alarm.
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.
Equalization (EQL) Option. The equalizer option causes the DS1 output signal of the H2TU-C to conform to
a 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 HDSL2 compatibility with the switch-to-protect features used in
Digital Loop Carrier (DLC) feeder applications, the H2TU-C has an Alarm Pattern (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
Bipolar Violation Transparency (BPVT) Option. The H2TU-C improves compatibility with Digital Loop
Carrier (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 of this feature is the need 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 and its associated remote units remove this limitation
and become BPV transparent by detecting and counting input BPVs at each end and then by replicating them at
the DS1 output port of the distant end.
The BPV count is converted into BPVs at the distant end during the following second at a rate of 1 BPV every
128 DS1 bits up to a maximum of 12000 (BER = 7.7 x 10
exceeds the maximum 10
DS1 Bit Error Rate (DBER) Option. The DS1 BER alarm occurs when any of the DS1 or DSX-1
performance monitoring parameters listed in
12:00:00 AM and 11:59:59 PM. These thresholds correspond to a 10
12:00:00 AM or when Master Clear is selected.
H2TU-C-388 List 7F
-3
BER required by most DLC systems.
Table 7
July 21, 2003
-3
). This maximum rate is more than adequate since it
exceed the counts shown for the 24-hour period between
-6
BER. All PM counters clear to zero at
Provisioning
19