Optically Amplified Multigigabit Links in CESNET2 network www.cesnet.c z Jan Radil Leoš Bohá � Miroslav Karásek TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 1
Optically Amplified Multigigabit Links in CESNET2 network Outline Motivation for extending the span length Numerical simulations @10 G Practical results (single channel, DWDM) Conclusions TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 2
Optically Amplified Multigigabit Links in CESNET2 network Motivations 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) TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 3
Optically Amplified Multigigabit Links in CESNET2 network Numerical simulations 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) TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 4
Optically Amplified Multigigabit Links in CESNET2 network Chromatic dispersion Different wavelengths propagate at different speeds Increases as the square of the bit rate 100 km of SMF G.652, 100 km of SMF G.652, without compensation with compensation TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 5
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 TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 6
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 TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 7
Optically Amplified Multigigabit Links in CESNET2 network Post-compensation, optimalization of the degree of compensation � DCR = |L DCF *D DCF |/(L SMF *D SMF ), L SMF = 270 km, P DCF = 0 dBm L SMF = 270 km, P DCF = 0 dBm L SMF = 270 km, P DCF = 0 dBm 21 9 3.8 Q 20 1.7 7.9 5.8 8 SMF input power, dBm 3.8 19 7 Q, dB P SMF = 16 dBm 18 6 17dBm 18dBm 19dBm 5 17 5.8 20dBm 21dBm 4 16 0.6 0.7 0.8 0.9 1.0 0.6 0.7 0.8 0.9 1.0 DCR DCR TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 8
Optically Amplified Multigigabit Links in CESNET2 network Post-compensation, optimalization of input powers P SMF and P DCF � DCR = 0.83, L SMF = 270 km, L DCF = 45 km L SMF = 270 km, L DCF = 45 km L SMF = 270 km, L DCF = 45 km -5 10 -6.3 -10 5 DCF input power, dBm -20 BER -15 log BER 0 P SMF =16 dBm -5 -20 17 dBm -13 18 dBm 19 dBm -10 20 dBm -25 21 dBm -15 -6.3 -15 -10 -5 0 5 10 16 17 18 19 20 21 DCF input power, dBm SMF input power, dBm TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 9
Optically Amplified Multigigabit Links in CESNET2 network Post-compensation, 270 km SMF +45 km DCF, P SMF =19 dBm, P DCF =0 dBm after SMF after DCF 25 4 20 optical power, µ W 3 power, µ W 15 2 10 1 5 0 0 17 18 19 17 18 19 time, ns time, ns after ELP after OBPF 1.0 25 0.8 20 PD voltage, a.u. optical power, µ W 0.6 15 0.4 10 5 0.2 0 0.0 17 18 19 17 18 19 time, ns time, ns TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 10
Optically Amplified Multigigabit Links in CESNET2 network BER as a function of input power: post-compensation scheme Eye diagram post-compensation 270 km SMF + 45 km DCF P SMF = 19 dBm, P DCF = 0dBm TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 11
Optically Amplified Multigigabit Links in CESNET2 network Practical results 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] TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 12
Optically Amplified Multigigabit Links in CESNET2 network Practical results – equipment used 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 TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 13
Optically Amplified Multigigabit Links in CESNET2 network Practical results – tested scenarios Scenario 1 – booster only Scenario 2 – booster and preamplifier TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 14
Optically Amplified Multigigabit Links in CESNET2 network Practical results – tested scenarios Scenario 3 – booster, preamplifier and Raman pump Scenario 1 – booster only for POS TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 15
Optically Amplified Multigigabit Links in CESNET2 network Practical results – problems pt.1 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 TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 16
Optically Amplified Multigigabit Links in CESNET2 network Practical results – 1 GE and 2.5 G POS Spee Loops Scenario DC OF Estimated Results d F Length Length GE 200 km Booster No No 220 km OK! Preamp GE 200 km Booster No Yes 270 km Short + 25 km packets Preamp 2.5 G 200 km Booster No No 220 km OK! Preamp 2.5 G 200 km Booster No Yes 270 km Failed + 25 km Preamp TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 17
Optically Amplified Multigigabit Links in CESNET2 network Practical results – 10 GE Loops Scenario DCF OF Estimated Results Length Length 100 km Booster No No 125 km OK! 100 km Booster Yes Yes 180 km OK! + 50 km Preamp 200 km Booster Yes Yes 220 km Failed Preamp Raman TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 18
Optically Amplified Multigigabit Links in CESNET2 network Practical results – problems pt.2 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 TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 19
Optically Amplified Multigigabit Links in CESNET2 network DWDM systems testing 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 TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 20
Optically Amplified Multigigabit Links in CESNET2 network DWDM systems testing Spectral diagram for 30 dBm input power, Spectral diagram for 30 dBm input power, after EDFA. before receiver. TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 21
Optically Amplified Multigigabit Links in CESNET2 network DWDM systems testing 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) TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 22
Optically Amplified Multigigabit Links in CESNET2 network Conclusions 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 TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 23
Optically Amplified Multigigabit Links in CESNET2 network Acknowledgements Thanks to Lada Altmanová, Stanislav Šíma and Martin Míchal from CESNET TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 24
Optically Amplified Multigigabit Links in CESNET2 network References [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 TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 25
Optically Amplified Multigigabit Links in CESNET2 network Thank you for your attention! TERENA Networking Conference May 19-22, 2003 Zagreb, Croatia 26
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