Control Building Fiber Preliminary Design Review December 5, 2001
ArrayTermination
Panel
I FPatch Panel
12 WDM per FIber
LOPatch Panel
M&CPatch Panel(TX & RX)
EmergencyCommunication
Patch Panel
TelephonePatch Panel
73 Fibers 73 Fibers 146 Fibers 73 Fibers 146 Fibers
Array FO TerminationRoom
North Arm FiberEntrance
(288 Fibersincl. spares)
East Arm FiberEntrance
(288 Fibersincl. spares)
West Arm FiberEntrance
(300 Fibersincl. spares)
E Array Option(180 Fibersincl. spares)
CB Main Distribution Frame
Cable Type Required
• Plenum Cable is required in the building
• 30-Fiber tight buffer cables will be used
Bit Error Rates
• Continuous On-Line Monitoring– Hardware and software – Part of Receiver– MCB access
• Error Flag Sent to the Correlator – Single threshold error flag
Transmitter Power
• Automated Test– Measured at Each Laser
• Manual Test– Can be measured at the Mux output– Can be measured at the output of the De-Mux
Optical Power
• Continuous Optical Power will be measured– 1% tap – The EDFA will measure the Optical Power– MCB access
• Total optical power is not a good indicator of BER
Eye Pattern
• Patch Panel– Manual measurements during reconfiguration
• Complete Diagnostic– Jitter– Q Factor– Noise Margin– Rise / Fall times
Test Patterns
• Generated at each Transmitter
• Nine Test Patterns– No Sync, alternating 1/0, all Ones, all Zeros
• MCB controlled
Frame Implementation
selector
32 bits
@
250 MHz
64 bitlatch
64 bitlatch
16 bit partioningand re-ordering
multiplexby 5
multiplexby 5
selector
multiplexby 16
16 Format bits@ 62.5 MHz
16 Format bits@ 62.5 MHz
64 bits@ 62.5 MHz
64 bits@ 62.5 MHz
80 bits@ 62.5 MHz
80 bits@ 62.5 MHz
16 bits@ 312.5 MHz
16 bits@ 312.5 MHz
16 bits@ 625 MHz
1 bit@ 10 GHz
160 bit Frames @10 GHz
Divided Sync Word
• Required to Identify Correct 1/2 Sequence
• 10 Bits long, – 6 bit identify Start-of-Frame– Barker Sequence - equal Ones versus Zeros
• Three Stage Synchronization Process
Three Stage Synchronization
• Stage 1 - Search bits for frame pattern
• Stage 2 – Monitor for “Correct” sync
• Stage 3 – If two “Bad” frames in a row
or 2-out-of-8 fames are “Bad”
Then Start Search Again
Scrambling
• Frame Synchronous Scrambling– Entire frame – except sync bits– Select pattern is modulo 2 added
• Pattern results in– Equal number of Ones/Zeros providing
• Balance ac content, sufficient transitions• Minimize low frequency content
Check Sum - BER
• Each 19 bits Generate a check Sum
• Only odd # of errors per 19 bits Detected
One error per frame is an
Error Rate of about 10-3