Jan Radil www.ces.net Optical networks and equipment czechlight.cesnet.cz March 1 , 2006 Masarykova Univerzita, Brno 2 Optical networks and equipment CESNET z.s.p.o. CESNET (Czech Educational and Scientific NETwork) - NREN in the Czech Republic Established as a legal entity ­ not for profit Association of Legal Entities (z.s.p.o.) in 1996 27 Universities Czech Academy of Sciences 52 staff members in Praha More than 150 part-time universities and Academy of Sciences staff working on projects March 1 , 2006 Masarykova Univerzita, Brno 3 Optical networks and equipment Participation on International Projects (GÉANT), GN2 6NET EGEE (SCAMPI), LOBSTER SEEFIRE PORTA OPTICA LUCIFER March 1 , 2006 Masarykova Univerzita, Brno 4 Optical networks and equipment CESNET z.s.p.o. - Funding Research plan: ,,Optical High Speed National Research Network and its New Applications" 2004 ­ 2010 Funded by Ministry of Education, Youth and Sports of the Czech republic and Association Members - budged approx. 12 MEuro/year Research activity annual report is available www.ces.net/doc/2005/ March 1 , 2006 Masarykova Univerzita, Brno 5 Optical networks and equipment CzechLight An experimental and breakable optical network For disruptive tests, not 24/7 NOC (Network Operation Centre) CzechLight optical equipment Parallel infrastructure together with a production network CESNET2 March 1 , 2006 Masarykova Univerzita, Brno 6 Utilization of dark fibres ­ Customer Empowered Fibre networks (the first DF line lighted in 1999, 2.5 Gb/s PoS, 327 km with 3 OEO regenerators) Now CESNET has 4200 km of leased dark fibres Cost effective deployment of multigigabit DF lines (N x 1 GE, N x 10 GE) with pluggable DWDM transceivers ­ GBIC, SFP, XENPAK, XFP Lack of optical equipment suitable for NRENs Development of our own optical amplifiers (and other equipment) Repeaterless or Nothing-in-line (NIL) approach, where possible and practicable Optical networks and equipment Motivations March 1 , 2006 Masarykova Univerzita, Brno 7 Back to Antiquity (mirrors, fire beacons, smoke signals) [Agr] The end 18th century with lamps, flags 1792, Claude Chappe with mechanical ,,optical" telegraph 1830 ­ the advent of telegraphy 1866 ­ the first transatlantic cable went into operation 1876 ­ the invention of telephone (A.G.Bell, U.S. Patent No. 174 465) 1940 ­ 3 MHz coax-cable system (repeater spacing 1 km) 1948 ­ 4 GHz microwave system 1960 ­ the invention of laser (suitable transmission medium?) 1960s ­ optical fibre (1000 dB/km) Optical networks and equipment A little bit of History (1) March 1 , 2006 Masarykova Univerzita, Brno 8 1970 ­ fibres with losses 20 dB/km Evolution of optical communication systems 850 nm, 1310 nm, 1550 nm, TDM, WDM, CWDM, DWDM 1980 ­ 45 Mb/s (1st generation) 1980s ­ 1310 nm, 1 dB/km, 100 Mb/s, multi-mode fibres Late 1980s ­ 2 Gb/s, single mode fibres, repeater spacing 50 km (2nd generation) 1990s ­ 1550 nm (problem with lasers, dispersion of fibres), 2.5 Gb/s or 10 Gb/s (3rd generation) 1990s - DWDM, optical amplification (4th generation) Today ­ 10 and 40 G waves, 160 channels ie x Tb/s, thousands of kilometers Optical networks and equipment A little bit of History (2) March 1 , 2006 Masarykova Univerzita, Brno 9 All electromagnetic phenomena are described by Maxwell`s equations An optical fibre (silica or non-silica) is a nonconducting medium without free charges Optical networks and equipment A little bit of Theory (1) t -=× B E t =× D H 0= D 0= B PED += 0 HB 0= E, H: electric/magnetic fields vectors D, B: electric/magnetic flux densities P: induced electric polarization M: induced magnetic polarization = 0 0: the vacuum permittivity 0: the vacuum permeability March 1 , 2006 Masarykova Univerzita, Brno 10 Div, grad, rot, Nabla, Laplace Optical networks and equipment A little bit of Theory (2) = zyx ,, f z f y f x f f grad,, = = FF div,, 321 = = z f y f x f FF rot=× = 2 2 2 2 2 2 2 zyx + + == March 1 , 2006 Masarykova Univerzita, Brno 11 Total internal reflection (discovered 1854) 1970: 20 dB/km (Kapron, Keck, Maurer), silica fibres Multimode (MM) and singlemode (SM) fibres Multimode: step-index (SI) or graded index (GI) MM SI: modal dispersion: different rays disperse in time because of the shortest (L) and longest (L/sinC) paths MM SI: 10 Mb/s, up to 10 km MM GI: parabolic index, lower modal dispersion, higher bit rates MM GI: 100 Mb/s, up to 100 km Plastic MM GI, for 1 GE (or even 10 Gb/s) Attenuation: 1 ­ 4 dB/km, <10 dB/km for plastic Optical networks and equipment Optical fibres March 1 , 2006 Masarykova Univerzita, Brno 12 Optical networks and equipment Optical fibres core: n1 cladding: n2 jacket: n0 n1 > n2 > n0 i r 1 2 csin n n = Numerical aperture NA, the maximum angle of the incident ray to remain inside the core Core: MM: 50 m/62,5 m, SM: 8,6 m ­ 9,5 m Cladding: 125 m NAcossin ci 10 =-== 2 2 2 1 nnnn March 1 , 2006 Masarykova Univerzita, Brno 13 Single mode (SM, Standard SMF, G.652) fibres Supports only one so called ,,the fundamental mode of the fibre" HE11 (TE11), all higher modes are cut off @ the operating wavelength An optical mode refers to a specific solution of the wave equation (satisfies boundary conditions, spatial distribution is constant as light travels along a fibre) TEMN or TMMN , magnitude of the transverse electric field or the transverse magnetic field at the surface of the fibre core The cutoff wavelength is specified in ITU G.650, the V parameter (or normalized frequency), V < 2,405 SM@1310 nm and 1550 nm, cutoff approx. 1200 nm 0,2 dB/km@1550 nm, 0,4 dB/km@1310 nm Optical networks and equipment Optical fibres March 1 , 2006 Masarykova Univerzita, Brno 14 MM: Intermodal dispersion (pulse broadening, the most important limiting factor) SM: Intermodal dispersion is absent, pulse broadening is present still because of Intramodal dispersion (or Group- velocity dispersion GVD), even laser pulses have finite spectral width and pulses are modulated GVD: different spectral components of the pulse travel at different speeds Increases as the square of the bit rate vg = (d()/d)-1 , ­ the propagation constant Intramodal dispersion has two components: Material dispersion Waveguide (or wavelength) dispersion Optical networks and equipment Optical fibres ­ Dispersion (1) March 1 , 2006 Masarykova Univerzita, Brno 15 D ­ the dispersion parameter [ps/(nm*km)] 2 - the GVD parameter D = DM + DW Material dispersion: dependence of the refractive index n on frequency , positive D Waveguide dispersion: nonlinear dependence of the propagation constant on frequency , negative D Optical networks and equipment Optical fibres ­ Dispersion (2) 22 21 c vd d D g -= = 2 2 2 d d = March 1 , 2006 Masarykova Univerzita, Brno 16 ITU ­ Limits of Chromatic dispersion Maximum CDC and D(), specified in G.652, G.653, G.655 G.652 (SSMF): Zero dispersion at 1310 nm G.653 (DSF): Zero dispersion at 1550 nm G.655 (NZDSF): Small dispersion at 1550 nm, positive/negative Dispersion-flattened fibre (DFF), positive/negative Dispersion Compensating fibres (DCF) Optical networks and equipment Optical fibres ­ Dispersion (3) March 1 , 2006 Masarykova Univerzita, Brno 17 Higher-Order Dispersion(s) Governed by the dispersion slope S = dD/d 3 - the third order dispersion parameter Optical networks and equipment Optical fibres ­ Dispersion (4) March 1 , 2006 Masarykova Univerzita, Brno 18 Optical networks and equipment Optical fibres ­ Cromatic Dispersion (1) 100 km of SMF G.652, without compensation March 1 , 2006 Masarykova Univerzita, Brno 19 Optical networks and equipment Optical fibres ­ Cromatic Dispersion (2) 100 km of SMF G.652, with compensation March 1 , 2006 Masarykova Univerzita, Brno 20 Optical networks and equipment Cromatic Dispersion Compensation Dispersion compensating fibres (DCF) A special kind of fibre, compensates all wavelengths (the only solution for ,,grey" transmitters) Adds link loss (and money), especially for long-haul applications Stronger non-linear effects (due to a smaller core diameter) Fibre Bragg gratings (FBG) Narrow-band elements ­ a stabilized DWDM laser is a must ,,Wide-band" FBGs available today (for 50 ITU DWDM channels) Signal filtering, spectrum shaping, tuneable compensators Cost effective solution March 1 , 2006 Masarykova Univerzita, Brno 21 Optical networks and equipment Cromatic Dispersion Compensation Optical Phase Conjugation (OPC) A nonlinear optical technique (midspan spectral inversion) The complex conjugate of a pulse-propagation equation Four-wave mixing in a nonlinear medium (phase conjugators) Electronic pre-compensation A relatively new technique An electrical signal is pre-distorted before converting into an optical domain Dispersion can be tuned for up to thousands kilometers of G.652 fibre March 1 , 2006 Masarykova Univerzita, Brno 22 Optical networks and equipment Cromatic Dispersion Compensation (FBG) March 1 , 2006 Masarykova Univerzita, Brno 23 Optical networks and equipment Cromatic Dispersion Compensation (FBG) March 1 , 2006 Masarykova Univerzita, Brno 24 Optical networks and equipment Cromatic Dispersion Compensation Typical values (receivers can have different tolerance to CD!) Bit rate (Gbit/s) Maximum length of G.652 link (km) 2,5 1000 10 80 40 4 March 1 , 2006 Masarykova Univerzita, Brno 25 Optical networks and equipment Cromatic Dispersion Measurements Modulated Phase-Shift Method (FOTP 169) Differential Phase-Shift Method (FOTP 175) Both phase-shift methods are accurate, measurement throught optical amplifiers, expensive Spectral Group Delay Measurement in the Time Domain (FOTP 168) Still accurate enough, no measurement through optical amplifiers Relative group delay is measured and the dispersion coefficient D is calculated TIA/EIA March 1 , 2006 Masarykova Univerzita, Brno 26 Polarization Mode Dispersion (PMD) Fibre birefringence (stress, temperature, imperfections) The stochastic phenomenon The fundamental mode HE11 (TE11) has two orthogonally polarized modes The two components with different propagating speeds disperse along the fiber The difference between the two propagation times is known as the Differential Group Delay (DGD) PMD is a wavelength averaged value of DGD Optical networks and equipment Optical fibres ­ PMD (1) March 1 , 2006 Masarykova Univerzita, Brno 27 PMD is measured and quoted in ps for a particular span and discrete components but its coefficient is in ps/(km)1/2 PMD accumulates as the square root of distance of a link A single span with high PMD dominates the total PMD for the whole network A big issue for older fibres (late 1980s, 80 000 000 km) and higher bit rates (10 Gb/s) Moder fibres have PMD of less than 0,5 ps/(km)1/2 Difficult to compensate (electronic) Optical networks and equipment Optical fibres ­ PMD (2) March 1 , 2006 Masarykova Univerzita, Brno 28 Optical networks and equipment Optical fibres ­ PMD (3) Second-order PMD For long-haul links, together with CD and laser chirping Bit rate (Gb/s) Maximum PMD (ps) PMD coefficient for 400 km fibre (ps/(km)1/2) 2,5 40 2,0 10 10 0,5 20 5 0,25 40 2,5 0,125 ITU proposed PMD values March 1 , 2006 Masarykova Univerzita, Brno 29 Optical networks and equipment PMD Measurements The Fixed Analyzer Method (FOTP 113) Well known, low price, problem with accuracy The Interferometric Method (FOTP 124) Well known, average PMD The Jones Matrix Method (FOTP 122) ,,Golden Standard" Measures DGD per wavelength TIA/EIA March 1 , 2006 Masarykova Univerzita, Brno 30 Optical networks and equipment Nonlinear Optical Effects When an intesity of elektromagnetic fields becomes too high, the response of materials becomes nonlinear For optical systems, nonlinear effects can be both advantageous (Raman amplification) and degrading (Four Wave Mixing, Self Phase Modulation) March 1 , 2006 Masarykova Univerzita, Brno 31 Optical networks and equipment Nonlinear Optical Effects Stimulated Raman Scattering (SRS) A signal is scattered by molecular vibrations of fibre ­ optical phonons Can occur both in forward and backward directions Shifted to longer wavelengths (lower energy) by 10 to 15 THz in the 1550 nm window Wide bandwidth of about 7 THz (55 nm) Maybe used for amplification (Raman fibre lasers), so called counter directionally pumping schemes In DWDM systems: transfer of power from shorter wavelengths to longer ones March 1 , 2006 Masarykova Univerzita, Brno 32 Optical networks and equipment Nonlinear Optical Effects Stimulated Brillouin Scattering (SBS) A signal is scattered by sound waves ­ acoustic phonons Shifted to longer wavelengths (lower energy) by 11 GHz in the 1550 nm window Narrow bandwidth of about 30 MHz A problem for monochromatic unmodulated signals March 1 , 2006 Masarykova Univerzita, Brno 33 Optical networks and equipment Nonlinear Optical Effects Self-Phase Modulation (SPM) When the intensity of the signal becomes too high, the signal can modulate its own phase The refractive index is no longer a constant Spectral broadening (positive chromatic dispersion) or spectral compression (negative CD) Significant for fibres with small effective areas (G.655, DCF) Higher bit rates (10 Gb/s) March 1 , 2006 Masarykova Univerzita, Brno 34 Optical networks and equipment Nonlinear Optical Effects (SPM1) Pin = 16,5 dBm March 1 , 2006 Masarykova Univerzita, Brno 35 Optical networks and equipment Nonlinear Optical Effects (SPM2) Pin = 20,0 dBm March 1 , 2006 Masarykova Univerzita, Brno 36 Optical networks and equipment Nonlinear Optical Effects (SPM3) Pin = 22,7 dBm March 1 , 2006 Masarykova Univerzita, Brno 37 Optical networks and equipment Nonlinear Optical Effects (SPM4) Pin = 24,0 dBm March 1 , 2006 Masarykova Univerzita, Brno 38 Optical networks and equipment Nonlinear Optical Effects (SPM5) Pin = 24,1 dBm March 1 , 2006 Masarykova Univerzita, Brno 39 Optical networks and equipment Nonlinear Optical Effects (SPM6) Pin = 25,8 dBm March 1 , 2006 Masarykova Univerzita, Brno 40 Optical networks and equipment Nonlinear Optical Effects (SPM7) Pin = 28,4 dBm March 1 , 2006 Masarykova Univerzita, Brno 41 Optical networks and equipment Nonlinear Optical Effects (SPM8) Pin = 30,1 dBm March 1 , 2006 Masarykova Univerzita, Brno 42 Optical networks and equipment Nonlinear Optical Effects Cross-Phase Modulation (CPM) A signal modulates the phases of adjacent channels March 1 , 2006 Masarykova Univerzita, Brno 43 Optical networks and equipment Nonlinear Optical Effects Four Wave Mixing (FWM) New ,,ghost" signals appear in the transmission spectral range Depends on several factors like launched powers, the CD, the refractive index, the fibre length Severe limitations for G.653 fibres and DWDM transmissions in the 1550 nm window (C band) Solution to this problem is to deploy L band DWDM systems (1565 nm ­ 1625 nm), where CD is high enough March 1 , 2006 Masarykova Univerzita, Brno 44 Optical networks and equipment Nonlinear Optical Effects (FWM1) Pin = 20 dBm 83 km, G.652 March 1 , 2006 Masarykova Univerzita, Brno 45 Optical networks and equipment Nonlinear Optical Effects (FWM2) Pin = 25 dBm 83 km, G.652 March 1 , 2006 Masarykova Univerzita, Brno 46 Optical networks and equipment Nonlinear Optical Effects (FWM3) Pin = 27 dBm 83 km, G.652 March 1 , 2006 Masarykova Univerzita, Brno 47 Optical networks and equipment Nonlinear Optical Effects (FWM4) Pin = 30 dBm 83 km, G.652 March 1 , 2006 Masarykova Univerzita, Brno 48 Optical networks and equipment Nonlinear Optical Effects (FWM5), TNC03 Att = 31 dB 124 km, G.652 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) March 1 , 2006 Masarykova Univerzita, Brno 49 Optical networks and equipment Nonlinear Optical Effects (FWM6) Spectral diagram for 30 dBm input power, after EDFA. March 1 , 2006 Masarykova Univerzita, Brno 50 Optical networks and equipment Nonlinear Optical Effects (FWM7) Spectral diagram for 30 dBm input power, before reciever. March 1 , 2006 Masarykova Univerzita, Brno 51 Optical networks and equipment Transmitters Laser and modulator Conversion of electrical signals into optical streams Laser: LED, Fabry-Perot (FP), Distributed Feedback (DFB) Direct or external (10 Gb/s) modulation Output powers: 0 dBm ­ 5 dBm Pluggable, DWDM ITU wavelengths (193,1 THz) GBIC (1 Gb/s), SFP (1 Gb/s ­ 2,5 Gb/s) Xenpak, XFP, Xpak, X2 (10 Gb/s) March 1 , 2006 Masarykova Univerzita, Brno 52 Optical networks and equipment Transmitters Price comparison GBIC 1550 nm: USD 6 000 (2002) from big vendors SFP DWDM: USD 2 000 (2005) Xenpak 1550 nm: USD 12 000 (2005) Xenpak DWDM: USD 31 000 (2005) from big vendors Xenpak DWDM: USD 5 500 (2005) from manufacturers XFP 1550 nm: USD 2 500 (2005) XFP DWDM: USD 4500 (2006) March 1 , 2006 Masarykova Univerzita, Brno 53 Optical networks and equipment Transmitters March 1 , 2006 Masarykova Univerzita, Brno 54 Optical networks and equipment Transmitters ­ Modulations 1 Different modulation formats, signal formats How to convert an electrical signal into an optical stream? On-Off Keying (OOK) A simple digital modulation scheme, easy to implement Intensity modulation with direct detection (IM/DD) Incoherent (the intensity only, no phase coherence) Two basic choices for the signal formats ­ return-to- zero (RZ) and nonreturn-to-zero (NRZ) Carrier suppressed (CS), Single side band (SSB), Vestigial sideband (VSB), Chirped (C) both for RZ and NRZ (CS-RZ, C-RZ,...) March 1 , 2006 Masarykova Univerzita, Brno 55 Optical networks and equipment Transmitters ­ Modulations 2 Coherent - well known from radio and microwave systems and literature Improvement of receiver sensitivity (up to 20 dB) when compared to IM/DD systems [Agrawal] More efficient use of bandwidth by increasing the spectral efficiency (higher tolerance to nonlinear effects, chromatic dispersion CD, polarization mode dispersion PMD) More complicated and more expensive March 1 , 2006 Masarykova Univerzita, Brno 56 Optical networks and equipment Advanced Modulation Formats Amplitude-shift keying (ASK) Phase-shift keying (PSK) Frequency-shift keying (FSK) Differential phase-shift keying (DPSK) Differential quadrature phase-shift keying (DQPSK) ­ Wi-Fi Optical Duo Binary ODB (also known as phase shaped binary modulation) March 1 , 2006 Masarykova Univerzita, Brno 57 Optical networks and equipment Advanced Modulation Formats Signal formats can be RZ, NRZ, CS-, etc. again DQPSK, ODB are multilevel modulations Multilevel ­ more amplitude levels (to achieve spectral efficiency better than 1 bit/s/Hz), 40 Gb/s is 10 Gbaud for a 16 level modulation DQPSK (information is encoded in the 4 differential optical phase between successive bits) ODB (in simplest scheme - two consecutive bits are summed -> a three level code is created, AM-PSK) RZ-DPSK, NRZ-DPSK, CS-RZ OOK, RZ-ODB have been studied extensively (better tolerance to different impairments) March 1 , 2006 Masarykova Univerzita, Brno 58 Optical networks and equipment Receivers Photodetector and demodulator PIN APD (better performance) Receiver sensitivity for certain BER 1 GE: - 34 dBm 10 GE: - 15 dBm/- 24 dBm BER: 10-9, 10-12 ,10-15 Coherent (transmitted signal plus local oscillator) and incoherent (OOK) receivers March 1 , 2006 Masarykova Univerzita, Brno 59 Optical networks and equipment Optical Amplifiers Fibre, Semiconductor (SOA), Raman Erbium Doped Fibre Amplifiers (EDFA) Really began a revolution in the telecommunications industry Late 1980s, Payne and Kaming (University of Southampton) OAs can directly amplify many optical signals Protocol, bit-rate transparent EDFAs working in the 1550 nm window (C band and later L band) March 1 , 2006 Masarykova Univerzita, Brno 60 Optical networks and equipment Optical Amplifiers EDFA High energy level, 1 s Low energy level Metastable energy level, 10ms 980 nm 1480 nm Er atoms Amplified signal Light Amplification by Stimulated Emission March 1 , 2006 Masarykova Univerzita, Brno 61 Optical networks and equipment Optical Amplifiers EDFA WDM WDM PUMP PUMP SIGNAL SIGNAL Forward, backward pumping Forward: lowest noise Backward: highest output power 980 nm: low noise 1480 nm: stronger pump sources (req. longer Er fibres) 1480 nm & backward; 980 nm & forward Single or dual stage (for DCF) Er doped fibre, 10 m ­ 100 m March 1 , 2006 Masarykova Univerzita, Brno 62 Optical networks and equipment Optical Amplifiers EDFA Output powers (5 Watts or more) Gain (30 dB), is not uniform across C (L) band Input power (- 35 dBm) Noise Figure (NF): theoretical minimum 3 dB ASE For L band: long Er fibres (> 100 m) Booster, in-line, preamplifiers March 1 , 2006 Masarykova Univerzita, Brno 63 Optical networks and equipment Optical Amplifiers March 1 , 2006 Masarykova Univerzita, Brno 64 Optical networks and equipment Other Optical Fibre Amplifiers Praseodymium Doped Fluoride Fibre Amplifier (PDFFA) 1310 nm, not as energy efficient compared to EDFA Problems with fluoride fibres, not very widespread Thulium DFFA (TDFFA) 1460 nm, 1650 nm the lifetime problems Neodymium DFA 1310 nm, fluoride fibre March 1 , 2006 Masarykova Univerzita, Brno 65 Optical networks and equipment Semiconductor Optical Amplifiers Cost effective solutions, especially for 1310 nm window Based on conventional laser principles Active medium (waveguide) between N and P regions High gain (up to 25 dB) Low output powers (15 dBm) Wide bandwidth High noise figure (8 dBm) InGaAsP ­ small and compact components March 1 , 2006 Masarykova Univerzita, Brno 66 Optical networks and equipment Semiconductor Optical Amplifiers Can be used as wavelength convertors, regenerators, time demultiplexors (OTDM), clock recovery devices EDFAs are more powerful and less noisy (but more expensive) But PDFAs are not so widespread and common, optical parameters (output powers and noise figures are not comparable with EDFAs) ­ SOAs can present an interesting solution 10 GE line cards for PC (PCI-X, PCI-E) S2io (Neterion), Chelsio, Intel with fixed 1310 nm transceivers only The only way to extend a reach is to deploy amplifiers (10 km is not enough, even for MANs in the Czech Republic) or use wavelength convertors (OEO ­ L2 Ethernet switches) March 1 , 2006 Masarykova Univerzita, Brno 67 Optical networks and equipment Semiconductor Optical Amplifiers March 1 , 2006 Masarykova Univerzita, Brno 68 Optical networks and equipment SOAs versus FOAs March 1 , 2006 Masarykova Univerzita, Brno 69 Optical networks and equipment Raman Amplification Not a discrete amplifier Stimulated Raman scattering effect Distributed amplification, a communication fibre itself is a gain medium Can add 40 km to increase a maximum transmitter-receiver distance Upgrading of existing links to add more channels A quite weak effect in silica fibre ­ very high powers have to be used Safety problems (automatic laser shutdown - ALS) March 1 , 2006 Masarykova Univerzita, Brno 70 Optical networks and equipment Raman Amplification Double Rayleigh scattering (DRS) Fibre acts like mirrors ie limits launch powers March 1 , 2006 Masarykova Univerzita, Brno 71 Optical networks and equipment Raman Amplification Counter-directionally pumping schemes March 1 , 2006 Masarykova Univerzita, Brno 72 Optical networks and equipment OAs and Practical Deployment Praha - Pardubice Since May 17, 2002 March 1 , 2006 Masarykova Univerzita, Brno 73 Optical networks and equipment OAs and Practical Deployment Praha ­ Pardubice, 189 km, 44 dB, 1 GE Praha ­ Plzeň (One Side Amplification), 123 km, 34 dB, 1 GE TX TX RX RX OF March 1 , 2006 Masarykova Univerzita, Brno 74 Optical networks and equipment OAs and Practical Deployment Brno ­ České Budějovice, 308 km, 70 dB, 2,5 Gb/s, PoS, without optical filters TX RX TX RX JIHLAVA March 1 , 2006 Masarykova Univerzita, Brno 75 Optical networks and equipment OAs and Practical Deployment Brno ­ Ostrava, 235 km, 51 dB, 1 GE (tested for 2,5 G PoS), without optical filters TX TX RX RX March 1 , 2006 Masarykova Univerzita, Brno 76 Optical networks and equipment PDFAs/SOAs and Ramans for 1310 nm Development of high-speed customer empowered fibre networks and availability of 10 GE LAN cards with 1310 nm transceivers stimulates the need for interconnection of stand- alone or hardware accelerated PCs at 10 Gbit/s rate Advantage ­ zero chromatic dispersion of standard single mode fibres (SSMF) at 1310 nm in, the 1310 nm transceivers are much cheaper than the 1550 nm ones Disadvantage ­ loss of SSMF at 1310 nm is almost twice as high as at 1550 nm March 1 , 2006 Masarykova Univerzita, Brno 77 Optical networks and equipment PDFAs/SOAs and Ramans for 1310 nm Praseodymium-doped fluoride fibre amplifiers (limited number of manufacturers, low saturated output power in comparison with EDFA, FiberLabs, FL8610-OB, Psat=16dBm, NF=5.5dB) Distributed amplification in the transmission fibre utilizing stimulated Raman scattering (Raman fibre amplifier (RFA), no pump LDs at 1250 nm, Raman fibre laser, IPG, Poutmax =2 W at 1250nm) Semiconductor optical amplifiers (InPhenix, IPSAD1301, Psat=10dBm, NF=7.5dB) Experiments with 10 GE March 1 , 2006 Masarykova Univerzita, Brno 78 Optical networks and equipment PDFAs/SOAs and Ramans for 1310 nm Similar configuration as for EDFAs plus Ramans Booster or preamplifier only Booster and preamplifier Booster and in-line amplifier Booster, preamp and Raman amplifier Dual booster (to increase the output power) and Raman Booster, inline and Raman March 1 , 2006 Masarykova Univerzita, Brno 79 Optical networks and equipment PDFAs/SOAs and Ramans for 1310 nm Eye diagram after preamp, l = 100 km March 1 , 2006 Masarykova Univerzita, Brno 80 Optical networks and equipment PDFAs/SOAs and Ramans for 1310 nm Eye diagram after preamp, l = 120 km March 1 , 2006 Masarykova Univerzita, Brno 81 Optical networks and equipment PDFAs/SOAs and Ramans for 1310 nm Eye diagram after preamp and optical filter, l = 120 km March 1 , 2006 Masarykova Univerzita, Brno 82 Optical networks and equipment PDFAs/SOAs and Ramans for 1310 nm Configuration Reach (km) Guaranteed 10 In lab, no amps 30 Booster 85 Booster and preamp 120 Dual booster and Raman 135 March 1 , 2006 Masarykova Univerzita, Brno 83 An optical kit composed from commercially available elements Cost effectivity & reliability Possibilities of future development Customer based OFA modules ­ EDFA for 1550 nm, PDFA for 1310 nm (10 GE line cards for PC ), Raman modules High power boosters, low-noise preamps, in-line amps... The result is: CzechLight amplifiers (CLAs) Why? What is CzechLight? Optical networks and equipment CzechLight Amplifiers March 1 , 2006 Masarykova Univerzita, Brno 84 An experimental and breakable optical network, testbed 10 G lambda to NetherLight (Amsterdam), a part of GLIF Started as 2,G G lambda, back in January 2003 To test new components before deployment (lab -> CzechLight -> CESNET2) Experimental traffic for Institute of Physics and other researchers Praha ­ FermiLab (1 GE) Praha ­ Taipei (1 GE) For high speed experiments like iGrid2005, SC2005 (full 10 G) http://www.ces.net/doc/press/2005/pr051219.html Optical networks and equipment CzechLight March 1 , 2006 Masarykova Univerzita, Brno 85 Optical networks and equipment CzechLight March 1 , 2006 Masarykova Univerzita, Brno 86 Optical networks and equipment CzechLight, GLIF March 1 , 2006 Masarykova Univerzita, Brno 87 Redundant PSUs from industry leading vendor DC voltages, fan speeds, temperatures are monitored Runs on flash disc (no vibration sensitive rotational parts), Linux based Interfaces: RS232, FastEthernet, USB, I2C Extensive management capabilities ­ console, LAN, GSM/GPRS, Wi-Fi, BlueTooth, SSH, SNMP Optical networks and equipment CzechLight Amplifiers Features March 1 , 2006 Masarykova Univerzita, Brno 88 Optical networks and equipment CzechLight Amplifiers CLA PB01 ­ preamplifier and booster, applicable as: DF link terminating OAs, inline OAs with CD compensation and for one side amplified (OSA) DF links OSA ­ all components are located at one place, star topologies CLA DI01 - dual inline OA, used during iGrid2005 and SC2005 experiments Now looking for manufacturers/partners March 1 , 2006 Masarykova Univerzita, Brno 89 Optical networks and equipment CzechLight Amplifiers OSA (One Side Amplification) ­ all components are located at one place, for star topologies March 1 , 2006 Masarykova Univerzita, Brno 90 Optical networks and equipment CzechLight Compensators To eliminate effects of Chromatic Dispersion A big issue for 10 G speeds (and beyond) in 1550 nm Dispersion compensation fibres ­ lossy, bulky and expensive Fibre Bragg gratings ­ a relatively new element, DWDM laser is a must (narrow band), today FBGs can compensate for 51 DWDM channels Signal filtering, spectrum shaping Cost effective solution Tuneable FBGs, not possible with DCFs (for e2e lightpaths, lambdas on demand) CLCs (an FBG plus management capabilities) March 1 , 2006 Masarykova Univerzita, Brno 91 Optical networks and equipment CzechLight OOO switches The last component for a transparent optical network ROADM vs. OOO switches 8 x 8 switching nonblocking matrix (16 x 16 in future) RS232 for configuring Management dtto CLAs March 1 , 2006 Masarykova Univerzita, Brno 92 Optical networks and equipment CLAs Deployment Both in CESNET2 (production) and CzechLight (experimental and breakable) networks Praha ­ Hradec Králové (CESNET2) 150.4 km of G.652, 35.7 dB@1550nm NIL, OSA (one side amplification) w/ CLA, 1 GE From Dec 2004 till Dec 2005, working without any problem CLA now moved to other edge link New 10 G Cross Border Fibre links to Poland and Austria are being prepared 10 G CBF to Slovakia operational (4 x 10 Gb/s) March 1 , 2006 Masarykova Univerzita, Brno 93 Optical networks and equipment CESNET2 March 1 , 2006 Masarykova Univerzita, Brno 94 Optical networks and equipment CLAs Deployment Praha ­ Brno (CzechLight) 298 km, mixture of G.652/G.655+/G.655-, 67 dB@1550nm Not NIL solution, without Ramans but with one inline CzechLight amplifier (DI01) Today 1 channel, 10 G SONET, DWDM transceivers, ready for up to 8 (16 with high power boosters and inline amps) 10 G DWDM SONET/SDH/Ethernet channels Deployment of (tuneable) FBGs and ROADMs/OOO switches is already planned March 1 , 2006 Masarykova Univerzita, Brno 95 Optical networks and equipment CLAs Deployment A bit of History :-) Started with 302 km of mixture of G.652/G.655+ fibre spools, EDFAs and Ramans, 65 dB@1550nm - working fine 297 km testing fibre loops, in the ground, mixture of G.652/G.655+/G.655-, 66 dB@1550nm - working fine The ,,true" 298 km/67 dB line Praha ­ Brno was (and still is) sort of bewitched, the BER was too high for our NIL configuration with Ramans :- ( March 1 , 2006 Masarykova Univerzita, Brno 96 Optical networks and equipment CLAs Deployment Praha ­ Hradec Králové (CESNET2) The rest of a rack is for CzechLight March 1 , 2006 Masarykova Univerzita, Brno 97 Optical networks and equipment CzechLight Equipment and NIL 302 km, 1 x 10 G DWDM channel, in lab on fibre reels With Raman amplifiers and dispersion compensating fibres 250 km, 4 x 10 G DWDM channel, in lab on fibre reels Without Ramans, with Fibre Bragg gratings 135 km, 1 x 10 GE, 1310 nm!, in lab on fibre reels No CD compensation at all, PDFA and Ramans for 1310 nm One historic footnote from February 2003 (TF - NGN, Rome) 10 Gigabit Ethernet In my opinion, we can go over 40 km :-) Again, our goal is Nothing-In-Line solution The latest result: 252 km, 2 x 10 GE grey 155O nm channels March 1 , 2006 Masarykova Univerzita, Brno 98 Optical networks and equipment Conclusions Development and deployment of new components Especially important (in our opinion) for academic and research community The results will (may) be used in a successor of SEEFIRE, GN2 (Joint Research Activities), Porta Optica Cross Border Fibre solutions Metropolitan Area Networks, Regional Optical Networks March 1 , 2006 Masarykova Univerzita, Brno 99 Optical networks and equipment Acknowledgement Lada Altmanová, Miroslav Karásek, Václav Novák, Martin Míchal, Stanislav Šíma, Karel Slavíček, Josef Vojtěch and Jan Gruntorád March 1 , 2006 Masarykova Univerzita, Brno 100 [1] Agrawal G.P., ,,Fiber-Optic Communications Systems", 2002. [2] Kartalopoulos S.V., ,,DWDM Networks, Devices and Technology", 2003. [3] Ramaswami R., Sivarijan K.N., ,,Optical Networks", 2nd edition, 2002. [4] Radil, J. - Karásek, M., ,,Experiments with 10 GE long-haul transmissions in academic and research networks.", In: I2 member meeting, Arlington, VA, 2004. [5] Vojtěch J., ,,CzechLight and CzechLight amplifiers". In: 17th TF- NGN meeting, Zurych, Switzerland, April 2005. [6] Vojtěch J., Karásek M., Radil J., ,,Extending the Reach of 10GE at 1310 nm ". In: ICTON 2005 meeting, Barcelona, Spain, 2005. Optical networks and equipment References 1 March 1 , 2006 Masarykova Univerzita, Brno 101 [7] www.seefire.org, Deliverables [8] czechlight.cesnet.cz, Publications [9] ECOC 2004 , 2005 proceedings [10] OFC 2004 , 2005 proceedings Optical networks and equipment References 2 March 1 , 2006 Masarykova Univerzita, Brno 102 Optical networks and equipment Thank you for your attention!