Optical Transport Networks: Operator s requirements and ICT DISCUS concepts

Transcription

1 TELECOM ITALIA GROUP Torino, July 2 nd, 2013 Optical Transport Networks: Operator s requirements and ICT DISCUS concepts Marco Schiano Telecom Italia, Transport Innovation Felipe Jimenez Arribas Telefonica I+D GCTO, Core Network Evolution group

2 Summary Core and metro networks requirements from operator s perspective Core networks design and implementation examples The DISCUS flat architecture Core networks evolution and next generation technologies

3 Summary Core and metro networks requirements from operator s perspective Core networks design and implementation examples The DISCUS flat architecture Core networks evolution and next generation technologies 3

4 Business impact of network characteristics Optical transmission and switching: high capacity Wide variety of services: traffic grooming and client i/f High reliability services: protection and restoration schemes Revenues 100 G efficient transmission: few regenerators Optimized design of Photonic, OTN and IP layer Scalability and modularity: pay as you grow Low power consumption and footprint Costs Capex Reliable equipment Effective OAM: end to end manageable services Opex 4

5 Traffic and power consumption 5

6 TEF Power consumption/co2 emissions in

7 Power consumption distribution 7

8 Energy costs projection 8

9 TEF Identified measures for 2015 target (30% power reduction) 9

10 OEO conversion Current networks are based on intensive power-consuming technologies that rely on electronic switching matrices. A reduction in the no. of OEO conversions on the E2E data path is essential. Several approaches have been considered: Optical switching within the core (mesh) by routing wavelengths. Data-network simplification, fewer levels and less electronic switching. Potential IP/MPLS offloading at OTN layer (fewer OEO conversions) or even at pure channel layer (no OEO conversion at skipped nodes). 10

11 OEO conversion: core network evolution Three steps are envisaged in the core network evolution: Assume two connections: A B and A C A Currently OTN offloading IP offloading B B B C A C A C IP/MPLS IP/MPLS IP/MPLS SDH SDH SDH OTN (sub- ) WDM mesh OTN (sub- ) WDM mesh OTN (sub- ) WDM mesh IP hops at intermediate nodes OEO conversion + packet processing. High IP-router port count. EOE conversion at intermediate nodes. Transponders at each node. All-optical, elastic (sub- ) routing from source to destination nodes in a transparent way. 11

12 OEO conversion: metro network evolution IP MPL S ETH SDH OTN WDM WDM ring WDM photonic mesh OEO conversion + transponders at each node photonic switching OTN/SDH processing at each transport node saving by removing the SDH layer IP-router high port count + packet processing at each IP node less proc. w/ OTN offloading 12

13 OEO conversion: metro network evolution IP MPL S ETH OTN WDM WDM ring WDM photonic mesh OEO conversion + transponders at each node photonic less OEO switching conv. w/ IP offloading OTN/SDH processing at each transport node saving by leaving out the SDH layer IP-router high port count + packet processing at each IP node less proc. OEO conv. w/ OTN w/ offloading IP offload. 13

14 OEO conversion: metro network evolution IP MPL S ETH OTN OTN WDM Sub- WDM Sub- WDM tech ring ring WDM photonic mesh OEO conversion + transponders at each node less WDM OEO ring conv. Sub- w/ IP tech offloading ring OTN/SDH processing at each transport node saving by leaving out the SDH layer IP-router high port count + packet processing at each IP node less OEO conv. w/ IP offload. 14

15 OEO conversion: metro network evolution IP MPL S ETH OTN Sub- Sub- WDM Sub- tech ring OBS, WDM OPST, photonic TSON... mesh New approaches OEO conversion like optical + transponders packet/burst at each switching node WDM where ring a (virtual) Sub- tech distributed ring Ethernet switch spans OTN/SDH a network processing region, no at OEO each is transport performed node saving at intermediate by leaving (real) out the switches SDH layer and every optical IP-router transponder high port can count be shared + packet to processing reach every at possible each IP destination. node less OEO conv. w/ IP offload. 15

16 Summary Core and metro networks requirements from operator s perspective Core networks design and implementation examples The DISCUS flat architecture Core networks evolution and next generation technologies 16

17 Telecom Italia new Photonic Backbone motivations To cope with a remarkable traffic increase from the domestic networks (especially the IP backbone) from International networks from the emerging wholesale market To decrease costs (both CAPEX and OPEX) To enhance reliability for critical services To reorganize the transport backbone into a single easily manageable platform, switching over multiple legacy DWDM systems 17

18 The domestic client networks TO MI 2 MI 1 SS X AL PC VR VE BO A PI FI P N G P RM 2 E RM R 1 M 1 BA TA TO AL GE SV CA IP backbone architecture OPB: Optical Packet Backbone CO BG BS M I MO PI FI BZ VR PD BO RI RM TS VE AN PG PE NA NL BA TA CA PA CT 2.5 Gbit/s SDH ring architecture Today used for structured VC4 services Excellent reliability (MS-SPRing) ASON meshed network SDH cross-connects and DWDM links Control Plane, centralized routing PA 18 CT CZ CRS 1 Tera-routers in the core 10 Gbit/s POS interfaces for all links 40 Gbit/s POS interfaces in the core

19 Carrying international traffic through Italy Telecom Italia Sparkle Pan-European Backbone Traffic originated in far and middle east is conveyed to Sicily by submarine systems It has to be delivered to northern Italy where the Telecom Italia Sparkle Pan European Backbone PoPs are located MedNautilus 19

20 Opportunities of new photonic technologies Ultra Long-Haul DWDM Multi-degree ROADM Fewer regenerators CAPEX savings End-to end provisioning Enhanced GMPLS Control Plane CP OCh protection and restoration OPEX savings Transparent Optical Tunnel CP CP Protected/ Restored Path CP CP CP CP CP 20

21 The Photonic Backbone structure 500 km 1000 km Tentative scheme of the new Backbone Network diameter: km (working-protection paths) Maximum number of hops: 11 Nodal degree: 2 5 (av. 3.1) Technology: 44 switching nodes based on ROADMs 71 ULH DWDM systems with 80 lambdas G.655 and G.652 fibers 10 and 40 Gbit/s OCh Ready for 100 G transmission 21

22 Preliminary network dimensioning Traffic load rough forecast in 2013: 542 OCh (mixed 10 and 40 Gbit/s) 100 OCh are used for traffic protection Maximum number of hops: 9 Maximum OCh length: 1600 km 6 Tbit/s total capacity No serious issues of lambda congestion at least with 2013 traffic estimates A double fully disjoint protection path is not available for all OCh due to cable topology limitations 22

23 Energy savings and other operational benefits Compared to transport on point-to-point DWDM systems, energy savings range between 20 and 30% Energy saving is mainly due to the regenerator number reduction, while ROADMs power consumption is very low Other important benefits are: Remarkable spare parts reduction (due to fewer regenerators); ~40% circuit creation cost reduction; Opportunity of relocating the circuits of legacy networks on the new backbone simplifying the transport in the backbone 23

24 Summary Core and metro networks requirements from operator s perspective Core networks design and implementation examples The DISCUS flat architecture Core networks evolution and next generation technologies 24

25 Today s networks vs. DISCUS architecture DISCUS is an end to end network architecture design for the next generation super fast broadband networks It is the sum of the parts; access/metro network, switching/routing nodes and core network that make it a winning solution - not simply the individual parts. Today s Electronics Centric Architecture DISCUS Optical Network Architecture Electronic conversion when crossing layer Inner Core PoPs All nodes both access and core Outer Core PoPs Metro PoPs Access PoPs with WDM Access PoPs ~100 node all-optical core Long reach WDM/TDM PON access Inner / outer core hierarchy scrapped No backhaul / metro network One electronic layer at Access core boundary Access nodes replaced by passive optics + optical amplifiers Multiple hierarchical layers + Large number of opto-electronic conversions + Large routing/ switching nodes + High customer port count = High cost and high power consumption = Limited scalability One hierarchical layer + Flat core + LR-PON = Minimum opto-electronic conversions = Minimum router/switch size & customer port count = Low cost and low power consumption = Scalable network 25

26 Access and core architecture 26

27 Access nodes (Local Exchange) evolution Small Local Exchange with Copper MSAN ( customers only (no fibre Medium Local Exchange with Copper MSAN & Fibre MSAN Large Local Exchange with Copper MSAN, Fibre MSAN & WDM MSAN Cu M SA N Cu M SA N F MS A N Cu M SA N F MS A N W MS W A N E O D F O D F O D F MDF MDF MDF Cable Chamber Cable Chamber Cable Chamber Access nodes in LR-PON optical network architecture Cable Chamber Cable Chamber Cable Chamber LR-PON optical card 1 st Generation LR-PON optical card 2 nd Generation DWDM 4x4 ONT Management Power 4x4 Spare fibre ports for future upgrade ONT Management Power 27

28 LR-PON = LE/CO & metro network bypass Working Metro-node ONTs fitted with DWDM bandpass blocking filter from day one Old Local Exchange Site Optical Amplifiers T x R x OLT ONT NTE DP Cabinet 4x4 ONT NTE Stand-by Metro-node T x R x OLT Initial LR-PON assumed to use a single wavelength and two fibre working in the long reach section from exchange site to metro-node 28

29 Evolution of LR-PON - by WDM upgrade Working Metro-node Exchange Site T x R x ONT ONT NTE NTE DP Cabinet 4x4 T x R x OLT Spare fibres for future technology upgrade e.g. coherent LR-PON Stand-by Metro-node T x R x Bandwidth upgrade is simple addition of OLT cards at the metro-node and ONU equipped to receive the new wavelengths. When tuneable receivers are installed at the ONU full wavelength flexibility is enabled. Other wavelengths can carry high bandwidth point to point links direct to the core at 10 to 100+ Gb/s. T x R x OLT 29

30 Fully flexible optical core node structure 30

31 Simplification of country network (UK example) Source BT UK With All Exchanges UK with~100 nodes 31

32 Simplification of country network (Ireland example) Ireland with all 1100 exchange buildings Ireland with 18 nodes 32

33 Power per user (Watts) Torino, July 2 nd, 2013 Power consumption benefits User power BAU v LR-PON + flat core Power per user: BAU v LR-PON + flat core BAU Watts per B'band fixed network user LR-PON + flat optical core Comparison of relative power consumption against user sustained bandwidth. BAU case versus LR-PON plus flat optical core LR-PON case power consumption is dominated by access power (ONU) consumption. BAU quickly becomes dominated by core network power consumption as user bandwidth rise Sustained user bandwidth (Mb/s) 33

34 DISCUS evolvable & sustainable network Remains economically viable as demand and services evolve and supports a range of business and ownership models Low power consumption Green network solutions Can scale to meet service growth requirements particularly those enabled by FTTP Access bandwidth scales indefinitely up to limits of fibre technology Can adopt new technologies while co-existing with previous generations re-use installed physical infrastructure Efficiently use network resources e.g. spectrum, bandwidth, infrastructure (cables & fibre), equipment and components, manpower, processing power, space, storage etc. Major reduction in electronic equipment per unit of user bandwidth Reduced number of nodes, interface ports, OEO conversions, and line cards Cost per unit bandwidth needs to fall almost inline with bandwidth growth 34

35 Summary Core and metro networks requirements from operator s perspective Core networks design and implementation examples The DISCUS flat architecture Core networks evolution and next generation technologies 35

36 Optical networks at a turning point More efficient use of optical bandwidth ESSIAMBRE et al., JLT, 2010 Mid term Today s Photonics with enhanced capacity Optical bandwidth broadening 2012 ~2020 ~2030 Recent record experiments New disruptive Photonics MIMO on multimode fibers Multicore fibers Photon s Orbital Angular Momentum Long term 36

37 Next generation photonic backbones Torino, July 2 nd, 2013 Towards more efficient wideband optical networks Enabling Technologies More efficient use of optical bandwidth Optical superchannels Configurable transponders Flexible optical grid Optical bandwidth broadening Raman amplification 37

38 Power Spectrum Torino, July 2 nd, 2013 Nyquist DWDM and superchannels Superchannel OCh can be closely spaced and managed as superchannels Nyquist DWDM channel spacing limit is the baud rate Channel spacing Df Optical Frequency Paper OTh3A.3, Poggiolini et al., "Ultra- Long-Haul Transmission of 16x112 Gb/s Spectrally-Engineered DAC-Generated Nyquist-WDM PM-16QAM Channels with 1.05x(Symbol-Rate) Frequency Spacing" BOSCO et al., JLT 2011 System reach is limited by non linear crosstalk (FWM-like impairment model) 50 G The narrower the channel spacing the 100 G higher the spectral efficiency and the shorter the system reach 150 G G.652 G G 38

39 Spectral Efficiency versus Reach tradeoff 200 G G.655 Span loss 25 db EDFA NF 5 db Gsymbol/s For a given modulation format Reach can vary by 70% for Df in the range GHz 150 G G About the same variation is observed for Spectral Efficiency BOSCO et al., JLT Channel spacing (GHz) 50 G Spectral Efficiency by Reach product (EDFA, G.652) 33.3 GHz provides the highest SE R product for almost all considered modulation formats 39

40 90 Hybrid DSP 90 Hybrid Power Spectrum DSP Torino, July 2 nd, 2013 Next generation transponders No dramatic change in symbol rate Configurable modulation format: DP-BPSK, DP-QPSK, DAC DAC DAC DAC Laser Optical modulator Optical modulator PC DP-8QAM, DP-16QAM Spectral shaping Electrical spectral shaping: DSP and DAC in the transmitter Optical carrier tunability on a flexible grid scheme Baud Rate Optical Frequency ADC ADC Soft Decision FEC: > 10 db coding gain PS Laser ADC ADC 40

41 Per Polarization Spectral Efficiency Torino, July 2 nd, 2013 Raman amplification Wideband 100 nm Raman systems already demonstrated 3 6 db OSNR reduction compared to EDFA Approximately reach doubling compared to EDFA 1518 nm 1620 nm ESSIAMBRE et al., JLT 2010 Puc et al., ECOC 2005 Systems with Raman approach Shannon limit Spectral Efficiency Optimized constellation and coding Sir Chandrasekhara Raman 1930 Nobel Prize 16 bit/s/hz spectral efficiency with 1000 km reach (dual polarization) 41

42 Network evolution scenarios Channel spacing [GHz] Today s WSON Scenario 1 Scenario 2 Scenario 3 (SE limit) Amplification EDFA EDFA RAMAN RAMAN Optical Bandwidth [nm] N. of DWDM channels Transponders bit rate [Gbit/s] Transponder s reach [km] Modulation format (dual pol.) <1000 BPSK QPSK QPSK 8QAM QPSK 16QAM Optimized constellation and coding 42

43 Kaleidon backbone as a benchmark k a e i d o n 44 ROADM nodes 71 DWDM ULH links (80 ) Network diameter: km (working-protection) Max. n. of hops: 11 Nodal degree: 2 5 (average 3.1) G.655 and G.652 fibers 40 and 100 Gbit/s OCh 43

44 Traffic composition and growth estimate Traffic baseline: 10 Tbit/s IP: 4.7 Tbit/s OTN: 5.1 Tbit/s wholesale: 0.2 Tbit/s IP is assumed to grow faster than other traffic Percentage over total traffic ranges from 48 to 80% 50% of IP traffic is protected 44

45 A/D A/D A/D A/D A/D A/D A/D Torino, July 2 nd, 2013 Traffic routing and network dimensioning Two options in network dimensioning: Maximum node degree 8 (1x9 WSS, 8 line ports, 2 add-drop ports) Maximum node degree 16 (1x20 WSS, 16 line ports, 5 add-drop ports) (1x9 WSS) 7 (1x20 WSS) 15 Minimum distance routing metric Traffic demand provisioning in order of decreasing length to minimize blocking Regenerators reduction by modulation formats fitting demand length 45

46 Kaleidon scalability analysis Raman Df=33 GHz 100/200 Gbit/s EDFA Df=33 GHz 150 Gbit/s Raman Df=33 GHz 400 Gbit/s EDFA Df=50 GHz 40/100 Gbit/s Total Photonic Layer traffic including IP protection 46

47 Conclusions A fourfold traffic increase can be supported by next generation photonic backbones if 100 nm Raman amplification is used together with 33 GHz grid and Gbit/s configurable transponders The scalability bound set by Shannon limit is still 4 times higher than the capacity of these advanced backbones For the Kaleidon photonic backbone there is a limited waste of optical bandwidth when a fixed 33 GHz spacing is used instead of a flexible grid 47

48 References R-J. Essiambre et al., Capacity Limits of Optical Fiber Networks, JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 28, NO. 4, FEBRUARY 15, 2010, pp G. Bosco et al., On the Performance of Nyquist-WDM Terabit Superchannels Based on PM-BPSK, PM-QPSK, PM-8QAM or PM-16QAM Subcarriers, JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 29, NO. 1, JANUARY 1, 2011, pp G. Bosco et al., Performance Limits of Nyquist-WDM and CO-OFDM in High Speed PM-QPSK Systems, IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 22, NO. 15, AUGUST 1, 2010, pp A. Puc, et al., Ultra-wideband 10.7 Gb/s NRZ terrestrial transmission beyond 3000 km using all-raman amplifiers, proceedings ECOC 2005, pp