CopperOptics PairGain HiGain HLU-388 User manual

PAIRGAIN TECHNOLOGIES Section 150-388-124
Technical Practice Revision 01
Engineering - PLANT Series June 21, 1996
Page 1
HIGAINTM LINE UNIT
MODEL HLU-388
List # Part Number CLEI Code
2D 150-1141-24 T1L2BBBAAA
CONTENTS PAGE
A. PRODUCT OVERVIEW
1. DESCRIPTION AND FEATURES 2
2. HIGAIN SYSTEM APPLICATIONS 2
3. FUNCTIONAL OPERATION 3
4. ALARMS 4
5. SYSTEM OPTIONS 6
6. HDSL LINE VOLTAGE OPTION 10
7. INSTALLATION 10
8. SPECIFICATIONS 11
9. CERTIFICATION 11
10. WARRANTY 12
11. TECHNICAL ASSISTANCE 12
B. APPLICATIONS WITHOUT HIGAIN
DOUBLERS (HDU-451)
12. SECTION INTRODUCTION 13
13. POWER CONSUMPTION 13
14. LOOPBACK OPERATION 14
15. TESTING 15
16. SYSTEM MAINTENANCE MENU
SCREENS 28
C. APPLICATIONS USING HIGAIN DOUBLERS
(HDU-451)
17. DOUBLER DEPLOYMENT RULES 36
18. POWER CONSUMPTION 36
19. LOOPBACK OPERATION 37
20. TESTING 39
21. SYSTEM MAINTENANCE MENU
SCREENS 50
Figure 1. HLU-388, List 2D Front Panel. The PairGain
HLU-388 is the local unit used in conjunction with the HRU-412
remote unit to provide a complete HiGain HDSL system.
CAUTION
This product incorporates static sensitive
components. Proper electrostatic discharge
procedures must be followed.

Section 150-388-124
Revision 01
Page 2
A. PRODUCT OVERVIEW
1. DESCRIPTION AND FEATURES
1.01 PairGain’s HiGain Line Unit Model HLU-388,
List 2D (see Figure 1) is the Central Office side of
a repeaterless T1 transmission system. When used in
conjunction with an HRU-412 HiGain Remote Unit, the
system provides 1.544 Mbps transmission on two
unconditioned copper pairs over the full Carrier Serving
Area (CSA) range. The use of doublers extends the range
up to 36,000 feet of AWG 24. The CSA includes loops
which are up to 12,000 feet of AWG 24 or 9,000 feet of
AWG 26 wire, including bridged taps. The HiGain system
uses HDSL (High bit rate Digital Subscriber Line)
transmission technology as recommended by Bellcore TA-
TSY-001210. HiGain complies with TR-TSY-000063
(Network Equipment Building System (NEBS) Generic
Equipment requirements) and TR-TSY-000499 (Transport
System Generic Requirements—TSGR) common
requirements.
1.02 The HLU-388 is compatible with the
following T1 repeater shelves:
23” Shelf
a) Larus FT2 1188 (28 slot connectorized).
b) AT&T DS1 Ext. (28 slot connectorized).
19” Shelf
a) Larus FT2 1187 (20 slot connectorized).
23” Cabinet Distant Terminal
a) Larus FT2 1190 (12 slots) for 51A cabinet
mount.
1.03 Revision History of this practice.
Revision 01—June 21, 1996
a) Initial release.
1.04 HLU-388, List 2D features:
•Selectable DS-1 pre-equalizer
•130 to 200 Vdc HDSL line power for doubler
and HRU-412
•Optional bipolar (±65 or ±100 Vdc) or unipolar
(-130 or -200 Vdc) HDSL line power voltage
via switch S2
•Front panel HDSL S/N margin display
•Compatible with Span Terminating Shelf (STS)
high density shelves
•Selectable loopback activation codes
•RS-232 maintenance port
•Compatible with PairGain Management System
•Non-volatile front panel operator setup
•Lightning and power cross protection on HDSL
interfaces
•784 kbps full duplex 2B1Q HDSL transmission
on two pairs
•Front panel status indicating LED
•On / Off front panel display power cycling
•DS1 LOS detector (125 consecutive zeros)
•Margin threshold alarm
•HDSL AIS and Smart-Jack AIS options
•Easy return to factory default user settings
•Circuit ID option
•30% less power consumption than List 1
2. HIGAIN SYSTEM APPLICATIONS
2.01 The HiGain system provides a cost-effective, easy-
to-deploy method for delivering T1 High Capacity
Digital Service (HCDS) over metallic pairs. The fiber-like
quality service is deployed over two unconditioned, non-
loaded copper pairs. Conventional in-line T1 repeaters are
not required. Cable pair conditioning, pair separation and
bridged tap removal are not required.
2.02 The general guidelines require that each loop have
less than 35 dB of loss at 196 kHz, with 135 ohms
driving and terminating impedances. The HiGain system
operates with any number of other T1, POTS, Digital Data
Service (DDS), or other HiGain systems sharing the same
cable binder group. HiGain systems can be used with
customers requiring DS1 service on a temporary or
permanent basis. The HiGain system also provides a means
of quickly deploying service in advance of fiber-optic
transmission systems. With the HiGain system, service can
be provided within hours. Fiber optic systems can be
installed at a leisurely pace and cut over from the installed
HiGain system when convenient to do so. The installed
HiGain system can then be easily removed and utilized
elsewhere.

Section 150-388-124
Revision 01
Page 3
3. FUNCTIONAL OPERATION
3.01 The HiGain system utilizes PairGain 2-Bit
1-Quartenary (2B1Q) HDSL transceiver systems to
establish two full duplex 784 kbps data channels between
the HLU-388, List 2D and a remotely mounted HRU-412
HiGain Remote Unit. This provides a total capacity of
1.568 Mbps between the two units.
3.02 A block diagram of the HLU-388, List 2D is
shown in Figure 2. The HiGain HLU-388, List 2D
receives a 1.544 Mbps DS1 data stream from the DSX-1
digital cross connect interface. The HLU-388, List 2D
contains a DSX-1 frame synchronizer controlled by an 8-bit
microprocessor that determines the type of framing on the
DS1 stream and synchronizes to it. The HLU-388, List 2D
recognizes Super Frame (SF) (including D4) or Extended
Super Frame (ESF) framing. When the data is unframed,
the HLU-388, List 2D arbitrarily defines a frame bit.
3.03 The HLU-388, List 2D contains a multiplexer that
generates two parallel 784 kbps data streams. The
data streams contain HDSL frames that are nominally 4704
bits (6 milliseconds) in length. The HDSL frames contain a
14-bit Frame Sync Word (FSW), 6-bit Cyclic Redundancy
Check (CRC), 21-bit operations channel and DSX-1
payload. The DSX-1 stream is separated into two parallel
streams that comprise the payloads of the HDSL channels.
The HLU-388, List 2D allocates the DS0 time slots
according to the version of HRU-412 to which it is
connected. Older version HRUs require the odd DS0 time
slots allocated to loop 1 and the even DS0 time slots to loop
2. Newer versions allocated DS0 time slots 1 through 12 to
loop 1, and time slots 13 through 24 to loop 2. The 8 kbps
frame bits of the DSX-1 stream are included on both HDSL
channels. The two formatted HDSL channels are passed to
the HDSL transceivers which convert them to the 2B1Q
format on the HDSL lines. The 2B1Q line code is designed
to operate in a full-duplex mode on unconditioned pairs.
The transceiver echo canceler and adaptive equalizer
receive the signal from the remote end in the presence of
impairments and noise on the copper pairs.
Figure 2. HLU-388, List 2D Block Diagram. PairGain’s HDSL technology provides full duplex services at standard T-1 rates over
copper wires between an HLU and an HRU, which comprise one HiGain system.

Section 150-388-124
Revision 01
Page 4
3.04 The received HDSL channels are processed
by the transceiver and then passed on to the HLU-
388, List 2D demultiplexer module. The demultiplexer
provides frame synchronization for each of the two HDSL
loops. The demultiplexer and HDSL transceivers work
under control of the HLU-388, List 2D microprocessor and
compensate for data inversions caused by tip-ring reversals
and loop swaps caused by pair reversals. The HiGain
system allows for tip-ring or pair reversals, but does not
tolerate split pairs. By synchronizing to the Frame Sync
Word (FSW) of each loop, the demultiplexer can
reconstruct the original 1.544 Mbps DS1 stream from the
payloads of the two HDSL loops. The CRC fields on the
HDSL streams allow the HLU-388, List 2D to determine if
errors are present on the channel due to excessive
impairments on the HDSL pairs or excessive impulse or
crosstalk noise.
3.05 The demultiplexer removes data link messages
from the HDSL loops and passes them to the
microprocessor. This mechanism allows operations
messages and status to be exchanged between the HLU-388,
List 2D and the HRU-412 remote unit.
3.06 The reconstructed HDSL data is buffered in a first-
in-first-out (FIFO) buffer within the demultiplexer.
A frequency synthesizer, in conjunction with the FIFO,
regulates the output bit rate and reconstructs the DSX-1
clock at the exact rate received from the remote end. The
HiGain system operates at T1 rates of 1.544 Mbps with up
to ±200 bps of offset.
3.07 A DSX-1 interface driver converts the input data
to an Alternate Mark Inversion (AMI) or Binary
Eight Zero Substitution (B8ZS) format. The DSX-1
equalizer is programmable to five different lengths, as
determined by the distance between the HLU-388, List 2D
and the DSX-1 interface. This provides CB-119
specification compliant pulses at the DSX-1 interface over a
range of 0 to 655 feet of ABAM-specification cable.
3.08.The HLU-388, List 2D contains two separate
power converters. The main power supply
converts -48 Vdc local battery to logic power for the HLU-
388, List 2D circuits. The line power supply converts the
-48 Vdc battery to either 130 Vdc (for non-doubler
applications) or 200 Vdc (for doubler applications), then
provides simplex power feed on the two HDSL line
interfaces. Switch S2 allows the user to configure the
HDSL line powering voltage to be unipolar (0 to -130 V
and 0 to -200 V) or bipolar (±65 V and ±100 V) (see
Figure 5.) The line power supply can be turned on or off by
the microprocessor and is automatically shut down in the
presence of line short circuits or microprocessor failure.
3.09 A 3-pin miniature 210 Bantam type connector jack
(Figure 3), is provided on the front panel of the
HLU-388. This connector provides access to HiGain’s
maintenance, provisioning and performance monitoring
interface via a RS-232 interface configured as Data
Communications Equipment (DCE). A 210 to DB-9 female
adapter is provided with every unit to facilitate the use of
standard RS-232, DB-9 cables. This connector provides
asynchronous access to the HiGain system maintenance
provisioning and performance monitoring firmware. The
port is configured as DCE with 8 data bits, 1 stop bit and no
parity. Operator interaction with the firmware is via an
ASCII terminal or a Personal Computer with asynchronous
communication software. Striking the Space bar several
times enables the HLU-388, List 2D to automatically match
the terminal line baud rate, from 1200 to 9600 baud. Figure
7 through Figure 14 show the menu selections available
from the terminal for non-doubler applications. Figure 16
through Figure 34 show the menu selections available from
the terminal for doubler applications. Table 8 defines the
terms used in the non-doubler System Status screen. Table
18 defines the terms for the doubler System Status screens.
4. ALARMS
4.01 The HLU-388 generates an Alarm message on its
front panel display for any of the alarm conditions
listed below. The front panel message which accompanies
each alarm condition is listed in bold letters. Since more
than one alarm condition can exist at any given time but
only one message can be displayed, the alarms are listed in
order of priority. Only the highest priority alarm is
displayed if more than one alarm condition exists. The
ALRM message precedes every specific alarm condition
display.
1. ALRM LOSW: Either HDSL loop lost sync
2. ALRM LLOS: Loss of HLU DSX-1 input
signal
3. ALRM RLOS: Loss of HRU DSX-1 input
signal
4. ALRM TLOS: A user option that causes the
loss of the HRU DS1 input from the CI to
initiate a logic loopback in the HRU.
5. ALRM H1ES: HDSL loop 1 has exceeded the
24-hour user-selected Errored Seconds CRC
threshold. If both H1ES and H2ES occur, only
H1ES is displayed on the front panel.
6. ALRM H2ES: HDSL loop 2 has exceeded the
24-hour user-selected Errored Seconds CRC
threshold. If both H1ES and H2ES occur, only
H1ES is displayed on the front panel.
7. ALRM DS1: The total number of bipolar
violations (BPV), at either the HLU or the

Section 150-388-124
Revision 01
Page 5
HRU DS1 inputs, have exceeded the 24-hour
user-selected threshold.
8. ALRM MAL1: The margin on HDSL loop 1
has dropped below the minimum threshold
value set by the RS-232 terminal Margin Alarm
Threshold; as described in Section 5.
9. ALRM MAL2: The margin on HDSL loop 2
has dropped below the minimum threshold
value set by the RS-232 terminal Margin Alarm
Threshold; as described in Section 5.
4.02 The HLU-388’s Status LED flashes red for the
duration of a minor alarm condition. Alarms 4 and
5 can be inhibited by selecting “None” for the ESAL system
option (see Section 5 for System Settings information). The
MAL(X) alarm can be DISabled by setting the margin alarm
threshold to 0. The minor alarm can be retired by executing
the Alarm CutOff (ACO) option. This is accomplished by
pressing the SEL button on the front panel. This turns the
alarm off and replaces the ALRM message with the ACO
message. However, the second part of the ALRM message,
which defines the cause of the alarm, remains. Both
messages remain until the alarm condition clears or another
alarm occurs. Disabling the ALM also retires an ACO
condition.
4.03 Pin 117, MJF, is driven to -48 VDC and the front
panel STATUS LED turns red whenever the on
board fuse opens. It emulates the function of the MJF
output from Pin 117 of normal high density DDM+
repeaters. Its normally floating output must never be driven
above ground or below -80 VDC. It can sink a current of
10 mA.
4.04 Pin (TBD) is the NMA serial bus. It is provided
for access to the HMU-388 shelf controller card
that will provide shelf management.
4.05 The HLU-388’s front panel tri-color Status LED
has the following states:
•GREEN - Normal Operation
•FLASHING GREEN - HDSL Acquisition
•FLASHING RED - Minor Alarm
(for conditions, see paragraph 4.02 above.)
•RED - Fuse Alarm
•YELLOW - Self-test in process or an HLU
Loopback in effect (CREM or NLOC)
•FLASHING YELLOW - HLU in Armed state
Figure 3. RS-232 I/O Pin-Outs. A 210 Bantam connector
jack on the front panel provides access to the menu interface of the
HLU-388.
Figure 4. HLU-388, List 2D Card-Edge Connectors. The
active pins are highlighted in black in the above illustration.