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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 1
May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 2
Optically Amplified Multigigabit Links in CESNET2 network - - PowerPoint PPT Presentation
Optically Amplified Multigigabit Links in CESNET2 network - - PowerPoint PPT Presentation
Optically Amplified Multigigabit Links in CESNET2 network www.cesnet.c z Jan Radil Leo Boh Miroslav Karsek TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 1 Optically Amplified Multigigabit Links in CESNET2 network
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 3
Experimental and theoretical results on extending the span length Repeaters for 1 GE, 10 GE or 10 G POS ? Repeater-less or nothing-in-line transmissions at 1 Gbit/s, 2.5 Gbit/s and 10 Gbit/s over standard G.652 SMF Fibre on the top of high-voltage poles, coast- island links, power supplies, maintenance ? Using optical amplifiers (EDFA, Raman)
Optically Amplified Multigigabit Links in CESNET2 network
Motivations
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 4
To estimate the maximum span length @10Gb/s for single channel transmissions Compensation of chromatic dispersion - DCF Post- and pre-compensation schemes Effect of self-phase modulation (SPM) For 1 G and 2.5 G - these effects negligible To keep the BER better than 10-12 (or Q > 7)
Optically Amplified Multigigabit Links in CESNET2 network
Numerical simulations
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 5
Different wavelengths propagate at different speeds Increases as the square of the bit rate
Optically Amplified Multigigabit Links in CESNET2 network
Chromatic dispersion
100 km of SMF G.652, without compensation 100 km of SMF G.652, with compensation
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 6
Optically Amplified Multigigabit Links in CESNET2 network
Self-phase modulation Signal modulates its own phase (Kerr effect) The effect increases with spectral density and the bit rate
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 7
Optically Amplified Multigigabit Links in CESNET2 network
Post and pre-compensation schemes, SMF 0,22 dB/km, DCF 0,55 dB/km
Post-compensation scheme Pre-compensation scheme
High quality parameters for fibres and lasers Possible problems with „real“ components Better - post-compensation
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 8
Optically Amplified Multigigabit Links in CESNET2 network
Post-compensation, optimalization of the degree of compensation
0.6 0.7 0.8 0.9 1.0 4 5 6 7 8 9 LSMF= 270 km, PDCF= 0 dBm Q, dB DCR
PSMF= 16 dBm 17dBm 18dBm 19dBm 20dBm 21dBm
DCR = |LDCF*DDCF|/(LSMF*DSMF), LSMF = 270 km, PDCF = 0 dBm
5.8 5.8 3.8 3.8 1.7 7.9
0.6 0.7 0.8 0.9 1.0 16 17 18 19 20 21 SMF input power, dBm DCR LSMF= 270 km, PDCF= 0 dBm
Q
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 9
Optically Amplified Multigigabit Links in CESNET2 network
Post-compensation, optimalization of input powers PSMF and PDCF
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- 10
- 5
5 10
- 25
- 20
- 15
- 10
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log BER DCF input power, dBm
PSMF=16 dBm 17 dBm 18 dBm 19 dBm 20 dBm 21 dBm
LSMF= 270 km, LDCF= 45 km
DCR = 0.83, LSMF= 270 km, LDCF= 45 km
- 6.3
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- 6.3
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16 17 18 19 20 21
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5 10 DCF input power, dBm SMF input power, dBm LSMF= 270 km, LDCF= 45 km
BER
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 10
Optically Amplified Multigigabit Links in CESNET2 network
Post-compensation, 270 km SMF +45 km DCF, PSMF=19 dBm, PDCF=0 dBm
17 18 19 1 2 3 4 after SMF
power, µW time, ns
17 18 19 5 10 15 20 25 after DCF
- ptical power, µW
time, ns
17 18 19 5 10 15 20 25 after OBPF
- ptical power, µW
time, ns
17 18 19 0.0 0.2 0.4 0.6 0.8 1.0 after ELP
PD voltage, a.u. time, ns
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 11
BER as a function of input power: post-compensation scheme
Eye diagram post-compensation 270 km SMF + 45 km DCF PSMF= 19 dBm, PDCF = 0dBm
Optically Amplified Multigigabit Links in CESNET2 network
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 12
1 GE, 2.5 G POS and 10 GE with NIL Three different configurations Booster, + preamp, + Raman Fiber field test-beds 25, 50, 100, 200 km Two GE backbone lines (189 km and 170 km) are currently in use in CESNET2 network [1]
Optically Amplified Multigigabit Links in CESNET2 network
Practical results
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 13
Cisco Catalyst 6503 with 1 port 10 GE 1550 nm linecards, GSR 12008 for POS Keopsys High power booster 30 dBm, low noise preamplifier 13 dBm Raman pump 24 dBm, provided by IREE Santec & JDS optical filters OFS DCF
Optically Amplified Multigigabit Links in CESNET2 network
Practical results – equipment used
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 14
Scenario 1 – booster only Scenario 2 – booster and preamplifier
Optically Amplified Multigigabit Links in CESNET2 network
Practical results – tested scenarios
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 15
Scenario 3 – booster, preamplifier and Raman pump Scenario 1 – booster only for POS
Optically Amplified Multigigabit Links in CESNET2 network
Practical results – tested scenarios
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 16
Not DWDM lasers (chirp, linewidth, modulators) Fibre field test-beds – cables with patchcords A lot of patchcords between lab and ODF Recalculating of length to more realistic figures…with attenuation 0,27 dB/km
Optically Amplified Multigigabit Links in CESNET2 network
Practical results – problems pt.1
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 17
Optically Amplified Multigigabit Links in CESNET2 network
Practical results – 1 GE and 2.5 G POS
Failed 270 km Yes No Booster Preamp 200 km + 25 km 2.5 G OK! 220 km No No Booster Preamp 200 km 2.5 G Short packets 270 km Yes No Booster Preamp 200 km + 25 km GE OK! 220 km No No Booster Preamp 200 km GE Results Estimated Length OF DC F Scenario Loops Length Spee d
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 18
Optically Amplified Multigigabit Links in CESNET2 network
Practical results – 10 GE
200 km 100 km + 50 km 100 km Loops Length Failed 220 km Yes Yes Booster Preamp Raman OK! 180 km Yes Yes Booster Preamp OK! 125 km No No Booster Results Estimated Length OF DCF Scenario
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 19
BER measurement ? No BERT equipment – we rely on PING POS line cards with BIP counters For 1 GE even better situation Difficult for 10 GE, we still believe in our simulations and PING testing Billions of long packets with 0% drop-outs
Optically Amplified Multigigabit Links in CESNET2 network
Practical results – problems pt.2
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 20
Verify the possibility to use single channel EDFA with DWDM system (up to 8 lambdas) Three DWDM platforms: Cisco 15540, Cisco 15200 (together with Cisco EDFA 15501) and Pandatel Fomux 3000 Keopsys optical amplifiers
Optically Amplified Multigigabit Links in CESNET2 network
DWDM systems testing
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 21 Spectral diagram for 30 dBm input power, after EDFA. Spectral diagram for 30 dBm input power, before receiver.
Optically Amplified Multigigabit Links in CESNET2 network
DWDM systems testing
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 22
Strong effects of SPM, CPM and FWM OSC mostly affected Single-channel EDFAs are OK for 5 channels For 16/32 channels you need really powerful booster (17 dBm for 1 channel corresponds to 2 dBm for 32 channels)
Optically Amplified Multigigabit Links in CESNET2 network
DWDM systems testing
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 23
We presented NIL solutions for multigigabit links „Better“ fibers Better equipment (low noise amps, DWDM lasers) More precise compensation: DCF and/or FBG BER measurement, eye-mask testing
Optically Amplified Multigigabit Links in CESNET2 network
Conclusions
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May 19-22, 2003 TERENA Networking Conference Zagreb, Croatia 24
Thanks to Lada Altmanová, Stanislav Šíma and Martin Míchal from CESNET
Optically Amplified Multigigabit Links in CESNET2 network
Acknowledgements
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[1] Šíma S., Altmanová L., „Development of the CESNET2 Optical Network“, TNC 2002 [2] Agrawal G.P., „Fiber-optic Communication systems“, J.Wiley, 2002 [3] Agrawal G.P., „Nonlinear Fiber Optics“, Academic Press, 2001 [4] Kartalopoulos S.V., „DWDM Networks, Devices and Technology“, J.Wiley, 2003
Optically Amplified Multigigabit Links in CESNET2 network
References
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