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150-231-175-01, Revision 01
Appendix B - Abbreviations
HLU-231 List 7E
September 23, 1998
47
A
PPENDIX
B - A
BBREVIATIONS
2B1Q
2 Binary,1 Quaternary
AIS
Alarm Indicator Signal
AMI
Alternate Mark Inversion
B8ZS
Bipolar with 8-zero Substitution
BPV
Bipolar Violation
CI
Customer Installation
CO
Central Office
CLOC
Customer Local Loopback
CPE
Customer Premises Equipment
CRC
Cyclic Redundancy Check
CREM
Customer Remote Loopback
CSA
Carrier Service Area
CSU
Channel Service Unit
DCE
Data Circuit-Terminating Equipment
DDS
Digital Data Service
DL
Data Link
DS1
Digital Signal, Level 1
DSX-1
DS1 Cross-connect Frame
ES
Errored Seconds
ESF
Extended SuperFrame
ESF DL
Extended SuperFrame Data Link
HCDS
High Capacity Digital Service
HDSL
High-bit-rate Digital Subscriber Lines
HDU
HiGain Doubler Unit
HLU
HiGain Line Unit
HRE
HiGain Remote Enclosure
HRU
HiGain Remote Unit
I-CPE
Interface-Customer Premises Equipment
LOS
Loss of Signal