Revision 01
December 22, 1997
150-319-142-01
4
PairGain Engineering - Plant Series
HLU-319 List 4B
F
UNCTIONAL
D
ESCRIPTION
This section describes the functions of the HLU-319 List 4B.
Operational Capabilities
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-319 List 4B and the HRU-412 List 8B. This provides a
total capacity of 1.568 Mbps between the two units.
The HiGain HLU-319 List 4B receives a 1.544 Mbps DS1 data stream from
the DSX-1 digital cross connect interface. The HLU-319 List 4B 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-319 List 4B recognizes Super Frame (SF), including D4 or Extended
Super Frame (ESF) framing. The HLU-319 List 4B arbitrarily defines a frame
bit for unframed data.
The HLU-319 List 4B 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 separates into
two parallel streams that comprise the payloads of the HDSL channels. The
HLU-319 List 4B allocates DS0 time slots 1 through 12 to loop 1, and time
slots 13 through 24 to loop 2 when used with an HRU-412 List 8B. 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
Operating Temperature
-40
°
C to +65
°
C
Humidity
5% to 95% (non-condensing)
Mounting
STS, high-density slot
Dimensions
Height:
12.1 cm
Width:
1.78 cm
Depth:
26.7 cm
