LTPH-UM-1109-01, Issue 1

Appendix B - Functional Operation

 

 

APPENDIX B - FUNCTIONAL OPERATION

ADC HDSL2 technology provides full-duplex services at standard DS1 rates over copper wires between an H2TU-C and an H2TU-R, which comprise one HiGain HDSL2 system. HiGain HDSL2 systems use Overlapped Pulse Amplitude Modulation Transmission with Interlocking Spectra (OPTIS) transceiver systems to establish full-duplex, 1.552 kbps data channels between the H2TU-C-231 and a remotely located H2TU-R.

Ablock diagram of the H2TU-C-231 is shown in Figure 33. The H2TU-C-231 receives a 1.544 Mbps DSX-1 data stream from the DSX-1 digital cross-connect interface. The H2TU-C-231 contains a DS1 frame synchronizer controlled by an 8-bit microprocessor that determines the type of framing on the DS1 stream and synchronizes to it. The H2TU-C-231 recognizes SuperFrame (SF) or Extended SuperFrame (ESF) framing. When the data is unframed, the H2TU-C-231 arbitrarily defines a frame bit.

D Tip 42

SIN

XRing 43

1

 

 

 

 

 

 

HDSL 2

 

BRG

 

 

 

 

 

 

 

 

 

 

 

XCVR

 

 

 

 

 

 

 

 

 

LINE

 

 

 

 

 

 

 

Fuse alarm 32

 

A

 

 

A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-48Vdc

39

 

 

 

HDSL2

 

-180 Vdc

+

 

 

T1

B

Power

 

 

 

 

 

Framer

Framer

Supply

 

 

 

B

Power Supply

 

 

 

 

 

 

 

 

(Ground isolated

 

 

15

 

 

 

 

 

_

 

 

 

 

 

 

and ground fault detect)

 

 

 

 

 

 

 

 

 

16

 

 

 

 

 

 

 

 

19

Ground

 

 

 

 

 

 

 

 

MODE SEL

 

 

 

 

 

 

 

 

 

 

 

44

 

Management bus

 

 

 

 

 

 

46

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LINE

 

Pre-equalizer

 

 

 

 

 

 

Select

 

Microprocessor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BRG

 

 

 

 

 

 

 

D

Tip 1

 

 

 

LEDs

RS-232 (front panel)

 

 

S

49

 

 

 

 

 

XOUT

150 Ring 1

20 Alarms

21

Tip

34

HDSL 2 SPAN

35 Ring

Figure 33. H2TU-C-231 List 2 Block Diagram

TIMING

The low-loop wander (0.5 UI max) of an H2TU-C-231, when used with remote units, allows the circuit to be used in all critical timing applications, including those used to transport Stratum 1 timing.

GROUND FAULT DETECT

The H2TU-C-231 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.

H2TU-C-231 List 2

January 9, 2002

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