From static WDM transport to software-defined optics Jörg-Peter Elbers, ADVA Optical Networking ECOC Market Focus - Sept 21 st, 2010 - Torino
Outline Introduction Technologies Benefits Applications Summary 2
Transport network evolution From static WDM to software-defined optics Fixed optical layer Rigid channel grid Programmable optical layer Gridless channel allocation Blocking add/drop Contentionless add/drop Variety of configurations Fixed interfaces ch. #1 #2 #3 #4 One universal node architecture Software-defined transceivers Fixed data rate Variable data rate Fixed modulation & FEC Fixed bandwidth Static connectivity Permanent connections (Semi-)manual set-up Adaptive mod./fec/equalization Variable bandwidth GMPLS bandwidth control SLA-based dynamic connections Full network automation 3
Comparison of SDR and SDO Radio spectrum (wireless channel) Optical spectrum (fiber-optic channel) [Source: http://www.draka.com] [Source: www.telecomcircle.com/2009/12/spectrum-refarming/] Software-defined radio (SDR) Software-defined optics (SDO) Coherent Optical RX Local osc. (laser) Universal Optical TX I Q I Q ADC ADC DAC DAC Baseband processor: Modem, Equalizer, FEC (DSP based) Amplifiers, ROADMs and fibers determine the usable optical spectrum 4
Technologies ROADMs MUX/ DEMUX Line WSS A/D MUX/ DEMUX Line WSS A/D WSS Line WSS A/D Switch FOADM ROADM Gen #1 ROADM Gen #2 ROADM Gen #3 Fixed add/drop Colorless/directionless Contentionless Fixed express path Configurable express path Simplified operations: More flexibility & automation, less blocking & card types Better spectrum exploitation: Programmable channel bandwidth (data rate, reach) l-grid 100 GHz 50 GHz Gridless channel allocation 100GHz 100GHz 50GHz 50GHz 25GHz 50GHz 75GHz [For details on ROADM technologies see eg. tutorial by S. Tibuleac, OFC/NFOEC 2009] 150GHz 5
Technologies Transceivers (long-haul) Increasing speeds drive programmability. Im 10G OOK Re intensity mod. Im 40G DPSK Re bipolar mod. Im 100G DP- QPSK Re multi-level mod. dual polarisation or 400G dual carrier mod.? OFDM, Superchannel, 1000G multi-carrier mod single polarisation direct detection optical dispersion compensation self-homodyne detection SFI5.1 (16x2.5G) intradyne detection ADC & RX-DSP 28GBd, 40nm CAUI/OTL4.10 (10x10G) ADC & RX-DSP, DAC, 56GBd, 28nm CDAUI/OTL5.16 (16x25G) integrated photonics TX-DSP multi-level electronics? LSI photonics 6
Technologies Control plane Packet services Private, TDM and wavelength services MPLS switching ODU switching Optical switching and transport Topology discovery Physical-constraints Service-assurance E2E path provisioning Optical restoration Multi-layer integration Bandwidth management Service-brokering Network defragmentation 7
Benefits of software-defined optics Muti-level modulation Multi-carrier modulation Client signal Symbol mapping Client signal Sub- Carrier Mapping Optical OFDM f Client signal Symbol mapping Client signal Sub- Carrier Mapping Optical OFDM f Signal adaptation to QoS, application & channel requirements Bandwidth, spectrum allocation, modulation format, coding, payload rate Better network utilization Exploitation of excess system margin, dynamic bandwith sharing Less optical interface variants 8
Applications & variations DWDM core networks ROADM-based switch/router interconnects Dual-polarisation multi-level/-carrier modulation Intradyne detection Variable channel bandwidth DWDM interconnects Short point-to-point links between data centers m-ary ASK, PSK, Direct/self-homodyne detection, Fixed channel bandwidth Network & switching nodes need to support software-defined optics. 9
Optical + electrical layer integration Traditional core networks Operational separation Rigid layer interconnects Operational simplification Integrated management & control Improved layer interworking Network & equipment optimization Reduced interface count Improved network utilization Increased network flexibility 10
Summary Evolution from static WDM transport to softwaredefined optics Constituting elements: Programmable optical layer Software-defined transceivers Powerful control plane Prospects: A simplified, scalable and automated bandwidth delivery for packet and circuit services. 11
Thank you jelbers@advaoptical.com IMPORTANT NOTICE The content of this presentation is strictly confidential. ADVA Optical Networking is the exclusive owner or licensee of the content, material, and information in this presentation. Any reproduction, publication or reprint, in whole or in part, is strictly prohibited. The information in this presentation may not be accurate, complete or up to date, and is provided without warranties or representations of any kind, either express or implied. ADVA Optical Networking shall not be responsible for and disclaims any liability for any loss or damages, including without limitation, direct, indirect, incidental, consequential and special damages, alleged to have been caused by or in connection with using and/or relying on the information contained in this presentation. Copyright for the entire content of this presentation: ADVA Optical Networking.
Quadrature modulation formats Change of constellation points increases bit rate Denser constellation packing reduces OSNR tolerance 13
Data Rate [Gigabits/second] Coherent Square-QAM 350 300 250 200 150 64-QAM 32-QAM 49-QAM 16-QAM 25-QAM 8-QAM 9-QAM Constant symbol rate Encoding integer bits per symbol Additive White Gaussian Noise (AWGN) channel No transceiver penalties taken into account 100 50 0 4-QAM DPSK -5 0 5 10 15 Format DP- QPSK DC-DP- QPSK Baud rate Bit rate BW_opt Penalty 25GBd 100Gb/s <50GHz 0dB 50GBd 400Gb/s <150GHz 6dB OSNR Margin [db] DP- 16QAM 50GBd 400Gb/s <75GHz 9.9dB 14