363-206-295
Circuit Pack Descriptions
Issue 1
December 1997
7-53
Transmission Circuitry
7
Transmit Direction.
7
The 21D/21D-U OLIU circuitry selects the three STS-1
signals from the TSI, adds SONET transport overhead, then byte-interleaves and
scrambles the signal in a frame synchronous scrambler. The output from the
multiplexer is an STS-3 signal that is used to amplitude modulate the LED
transmitter, converting the electrical signal to an NRZ-encoded IS-3 optical signal.
Receive Direction.
7
In the receive direction, the optical receiver converts the light
pulses from an IS-3 optical signal to equivalent electrical pulses. The received
signal may be either NRZ- or RZ-encoded. The output from the optical receiver
goes into a timing recovery device. The device recovers received clock (155.520
MHz) and uses it to retime the received data, providing a retimed STS-3 signal.
The demultiplexer circuit accepts the STS-3 bit stream, frames on the incoming
signal, descrambles it, demultiplexes it into three STS-1 signals, and processes
IS-3 transport overhead. The overhead information is sent to the OHCTL circuit
pack via the intra-shelf control bus and the transport overhead channel interface.
The STS-1 outputs from the demultiplexer are sent to the pointer processor that
performs pointer interpretation and generation on each received STS-1, using the
local timing signals. The output of the pointer processor is three STS-1 signals,
frame synchronous to each other.
Control Circuitry
7
The 21D/21D-U OLIU circuit pack interfaces with the SYSCTL and OHCTL circuit
packs.
The 21D/21D-U OLIU provides maintenance elements for reporting the status of
the circuit pack, status of the incoming STS-1 and IS-3 signals, as well as
inventory information (
CLEI code, date of manufacture, etc.). These maintenance
elements are used by the SYSCTL for fault detection and isolation. Conversely,
the 21D/21D-U OLIU responds to control signals from the SYSCTL, such as LED
operation and protection switching.
The 21D/21D-U OLIU accesses the IS-3 transport overhead and routes it via the
transport overhead channel interface to the OHCTL.
Timing Circuitry
7
Each TSI circuit pack sends timing signals to each 21D/21D-U OLIU circuit pack.
The 21D/21D-U OLIU monitors activity on both timing inputs. It normally selects
the signals from the active TSI as requested by the SYSCTL. If there is a failure of
the active input, the SYSCTL may command the 21D/21D-U OLIU to select the
OLIU input.
Содержание DDM-2000 OC-12
Страница 1: ...363 206 295 Issue 1 December 1997 DDM 2000 OC 12 Multiplexer Release 7 0 User Service Manual Volume I ...
Страница 37: ...Tables xxxviii Issue 1 December 1997 A A SONET Overview A 1 SONET Payloads A 18 A 2 SONET Transport Rates A 19 ...
Страница 506: ...INS PROG 8 of 8 Page INS PROG COMMANDS RELATED rtrv eqpt rtrv ne OC 12 DDM 2000 1997 December 1 Issue 11 89 ...
Страница 528: ...RTRV ATTR ALM 2 of 2 Page RTRV ATTR ALM COMMANDS RELATED set attr alm OC 12 DDM 2000 1997 December 1 Issue 11 111 ...
Страница 565: ...RTRV OC3 3 of 3 Page RTRV OC3 COMMANDS RELATED rtrv sync 11 148 1997 December 1 Issue OC 12 DDM 2000 ...
Страница 664: ...SET FEAT 3 of 3 Page SET FEAT COMMANDS RELATED rtrv feat OC 12 DDM 2000 1997 December 1 Issue 11 247 ...
Страница 766: ... Ctl T TOGGLE 2 of 2 Page Ctl T TOGGLE COMMANDS RELATED logout rlgn OC 12 DDM 2000 1997 December 1 Issue 11 349 ...
Страница 847: ...Multiplexer OC 12 DDM 2000 7 Release TARP TOP Manual User Service II Volume 363 206 295 1 Issue 1997 December ...
Страница 867: ...363 206 295 TOP Maintenance and Operation BLANK LEFT INTENTIONALLY PAGE THIS 12 1997 December 1 Issue ...
Страница 1145: ...Order Circuit 363 206 295 NTP 029 1 of 1 Page 1997 December 1 Issue Unused LISTED ORDER IN BELOW ITEMS DO TO GO DETAILS FOR ...
Страница 1146: ...Order Circuit 363 206 295 NTP 030 1 of 1 Page 1997 December 1 Issue Unused LISTED ORDER IN BELOW ITEMS DO TO GO DETAILS FOR ...
Страница 1182: ...Turnup System 363 206 295 NTP 033 1 of 1 Page 1997 December 1 Issue Unused LISTED ORDER IN BELOW ITEMS DO TO GO DETAILS FOR ...
Страница 1243: ...Clearing Trouble 363 206 295 TAP 107 1 of 1 Page 1997 December 1 Issue Unused ...
Страница 1393: ...363 206 295 DLP 513 1 of 1 Page 1997 December 1 Issue Unused ...
Страница 1394: ...363 206 295 DLP 514 1 of 1 Page 1997 December 1 Issue Unused ...
Страница 1456: ...363 206 295 DLP 523 7 of 7 Page 1997 December 1 Issue OC 12 via Access Broadcast Video for Cross connections of Example 4 Figure ...
Страница 1465: ...DLP 525 363 206 295 1997 December 1 Issue 6 of 2 Page Schematic Ring Virtual ATM Sample 1 Figure ...
Страница 1469: ...DLP 525 363 206 295 1997 December 1 Issue 6 of 6 Page Ring Virtual ATM OC 12 DDM 2000 for Cross connections of Example 4 Figure ...
Страница 1565: ...363 206 295 DLP 543 6 of 5 Page 1997 December 1 Issue Network Broadcast Video of Test Transmission 2 Figure ...
Страница 1566: ...DLP 543 363 206 295 1997 December 1 Issue 6 of 6 Page Network Ring Virtual ATM of Test Transmission 3 Figure ...