Green Photonics in Switching : Rod Tucker Centre for Energy-Efficient Telecommunications University of Melbourne

Transcription

1 Green Photonics in Switching : Rod Tucker Centre for Energy-Efficient Telecommunications University of Melbourne

2 Power Consumption (W) Power Consumption of the Global Internet 0 3 Global electricity supply 0 0 Power Consumption of Internet (Including servers) % p.a. Data growth Fixed access only 0% p.a. Growth in user numbers billion users Year Source: Tucker 0

3 Inside the Network Core Network Metro/Edge Network Access Network Core Router Fiber Broadband Network Gateways Ethernet Switch DSLAM Cu DSL Edge Routers OLT PON Splitter Fiber FTTP Hot spots OLT ONU Cabinet DSLAM Cu FTTN Server Storage Data Center Server Storage Content Distribution Network 3

4 Data Centers and Content Servers Load-Balancing Switches Border Routers 5% of traffic to users 5% of traffic to other data centers Aggregation Switches 80% of traffic stays in data center Racktop Switches Racks of Servers 4

5 Energy per Bit (nj) Energy Consumption of Switches Router Packet switch SDH Cross-connect OTN Cross-connect Source: O. Tamm et al Year 5

6 nano-joules per bit Equipment Energy Consumption Trends 0000 Router Energy Efficiency 000 Cisco AGS Linear fit gives ~5% improvement pa 00 Wellfleet BCN Cisco GSR 000 Actual improvement may be declining 0 Cisco GSR 000b Avici TSR Cisco CRS ALU7750 Cisco CRS Year Source: Nielsen, ECOC 0 6

7 Power Consumption (W) Power Consumption of the Global Internet 0 Global electricity supply (3% p.a.) 0 Total (00 Technology) Total 0 0 Access (PON) % p.a. technology improvement Year

8 Energy per User bit (mj) Average Access Rate (Mb/s) Network Energy per User Bit Core and Metro Switches/Routers PON Total 0 0. Optical Transport Year 8

9 Network Energy per Bit (J) Gap Between Theory and Practice 0-4 Global Network 0-5 Access Current Trends Transport Switches Lower Bounds x Transport Year Source: Tucker, JSTQE 0 9

10 Gap Between Theory and Practice Laser efficiency, interconnects, system penalties, system margins, etc E function E E Total min function E overheads E E min Total Loss, Inefficiencies E min Key Function Subsystem Overheads Management and control, interconnects, power supplies, etc. Source: Tucker, JSTQE 0 0

11 How can Photonics Green the Internet? Optical bypass in the core network /OTN/, /Ethernet, etc. GMPLS Agile optical switching in data centers and content servers Switching layer energy consumption Crosstalk and Scalability Some examples

12 GMPLS Controller Optical Bypass and GMPLS ~ 5 nj/bit < 0. nj/bit (Short Reach) TDM ~ nj/bit < nj/bit (Long Reach) Link OXC Link << nj/bit

13 Optical Bypass in the Core Core Router TDM TDM TDM Core EDFA TDM TDM Fibre TDM TDM Energy savings ~ 40-50% can be achieved by ASON-enabled network compared to legacy / network. 3

14 Power Saving (%) Control Element Control Element Optical Bypass and GMPLS Links OXC Links / (GMPLS) /SDH/ (GMPLS) TDM Links OXC Links Reference: Links Patch panel Links Legacy / Mean Utilisation Legacy /SDH/ Links TDM Patch panel Links NSFNET 4 nodes, links network, 00 wavelengths Feng et al., OFC 0 4

15 Optical Networking in Data Centers Controller Optical Switch (~000 ports) Some Options: Phased-array Fast (< 0 ns) switches SOA-based Low crosstalk gate arrays AWG-based Low power switches Micro-ring resonators Border Router Racktop Switches 0 00 Gb/s Servers 5

16 Energy Consumption in Optical Switch Switch Device supply power, P supply Key factors: Loss-compensation amps Interconnects Drivers Interface energy B data Optical Device Interface (R/C) Analog/Digital E bit P supply B data E c R B controller data N Interconnect (optical/electrical) Driver R controller Device control energy, E c N Controller

17 SOA Gate Arrays Benes SOA Gate Array Crosstalk Signal 0 ER ER > 43dB Input Output 3 SIR 30 db Driver P SOA P SOA driver Gate Control ~W x 0 4 SOA gates 3-dB Coupler 000 Broadcast and Select SOA Gate Array :000 splitter 000: combiner Crosstalk Signal 000 ER P SOA driver ER > 60 db W 000 :000 splitter : combiner splitters 0 6 SOA gates 000 combiners 7

18 > 0 6 control lines Phased-Array and AWG Switches Spanke Phased-Array Switch Crosstalk Signal 000 ER ER > 30 db ~ 000 analog control lines x 000 switch ~ 000 control lines 000 x switch Energy dominated by large numbers of analog control lines 000 x 000 switch x switch 000 T. Tanemura and Y. Nakano, IEICE, 008. (Also Workshop ) Input TWC P tune Output AWG Array 50 x 00 AWG 00 x 00 AWG Andrea Bianco Workshop 00 x 50 AWG P FWC Driver P tune driver Wavelength Control P TWC ,000 TWCs 0,000 AWGs,000 TWCs Interconnects 0 AWGs,000 TWCs,000 FWCs 8

19 Dilated Benes Ring Resonator Switch FWCs Control lines Dilated crosspoints > 40 db CMOS driver 000 Resonance thermal controllers 00 Lee et al., IEEE Photonics Society Annual meeting, 00 Andrea Bianco, Workshop Crosstalk vs. loss trade-off > 40 db loss for 000 x 000 switch 9

20 Energy per Bit (J) Optical Switch Technologies Compared 0-7 Electrical Interconnect ( MW) 600 W Phased-Array Spanke Optical Interconnect AWG (3 kw) 0 00 Bit Rate per Port (Gb/s) Total power consumption of switch 000 x 000 No controllers No buffering 0

21 Conclusions Switching and routing is becoming a major contributor to energy consumption in the network GMPLS combined with optical bypass can offer modest improvements in network energy consumption Opportunities for Green Optical Switching in data centres Control and interconnect energies may dominate System-level analysis is necessary 50 Ω