Appendix B - Functional Operation
152-319-100-02, Revision 02
54
April 21, 2000
H2TU-C-319 List 1 and List 1C
A
PPENDIX
B - F
UNCTIONAL
O
PERATION
PairGain HDSL2 technology provides full-duplex services at standard T1 rates over copper wires between an
H2TU-C and an H2TU-R, which comprise one HiGain Solitaire system. HiGain Solitaire systems use PairGain
Overlapped Pulse Amplitude Modulation (PAM) Transmission with Interlocking Spectra (OPTIS) transceiver
systems to establish full-duplex, 1.552 kbps data channels between the H2TU-C-319 and a remotely located
H2TU-R.
shows a block diagram of the H2TU-C-319. The H2TU-C-319 receives a 1.544 Mbps DSX-1 data
stream from the DSX-1 digital cross-connect interface. The H2TU-C contains a DS1 frame synchronizer
controlled by an 8-bit microprocessor that determines the type of framing on the DS1 stream and synchronizes
with it. The H2TU-C recognizes Superframe (SF), including D4, or Extended Superframe (ESF) framing.
Figure 29.
H2TU-C-319 Block Diagram
T
IMING
The low loop wander (0.3 UI max) of an H2TU-C, when used with compatible regenerators and remote units,
allows the circuit to be used in all critical timing applications, including those that are used to transport Stratum 1
timing.
G
ROUND
F
AULT
D
ETECT
The H2TU-C has a Ground Fault Detect (GFD) circuit which detects a ground or a resistive path to ground on any
wire of the HDSL2 loop. This makes the product compliant with the Class A2 requirements of GR-1089.
