Andrew Lord. The economic benefits of all-optical core networks around Europe

Transcription

1 Andrew Lord The economic benefits of all-optical core networks around Europe

2 Outline Acknowledgements Rationale for an all optical network Designing all-optical networks Economics Conclusions

3 Acknowledgments Nobel EU collaborative project funding much of this work Economic modelling in conjunction with Polatis (Many thanks to Richard Jensen) (Booth 1940 in exhibition)

4 Bandwidth The Margin Challenge Relative growth Bandwidth Bandwidth Costs Greater bandwidths -New services - Maintain/grow revenues Relative growth Revenues Revenues Costs But costs rise faster Margins are eroded 10 0 Incremental Costs

5 How do we sustain revenue growth? As bandwidth demand increases More equipment is purchased Higher sales volumes leads to cheaper equipment How quickly does the equipment price need to fall to maintain revenue growth?

6 Price Reductions with Volume CD Players, 81% Relative unit price Optical fibre, 75% computer memory, 70% What we need to economically grow bandwidth beyond broadband, 54% Relative bandwidth volume Source: Schumate, OFC 2002

7 So how do we achieve required cost reduction? Optical components (lasers, fibre etc) follow ~75% volume price reduction We need ~54% volume price reduction to economically grow bandwidth beyond today s broadband Answer is to eliminate equipment, interfaces and nodes from the network Two Components: 1. Integrate access and metro using long reach PON 2. Optical inner core network

8 Network evolution Today Logical Nodes Today ~80,000 PCPs in the Access Network ~100,000 Remote Concs, DSLAMS & Data Muxes ~ Voice Switches and Data Cross Connects ~170 Core Switches (DMSU / NGS) Data Centre International Networks Internet Peering End Customer 21C Logical Nodes Future Begin Fibre to the PCP ~13,500 Multi- Service Access Nodes ~100 Metro Nodes ~10 Core Nodes Aggregation Service Edge Core ~ 5 inodes Intelligence Logical Nodes Long reach Vision End Customer ~30k ~100 Metro Nodes Optical core

9 Core optical layer ~100 grooming nodes (ELECTRONIC) Intelligent Photonic Inner core Network Long reach optical access 100km Optical control plane Ultimate aim: Reduce BT network to ~100 exchanges

10 BT Core network schematic

11 Traffic bypassing core nodes % Traffic 25% 20% 15% 10% Traffic Routing in Opaque Design BT Core network 79 node model Assumes minimum hop routing No optical protection paths Therefore a LOW estimate of bypass traffic 5% 0% >9 Hops Large future traffic entering core from broadband access network High % traffic will bypass core nodes en-route to destination 74% transponders used for transit traffic

12 Opaque vs transparent? Mux / demux opaque intermediate grooming using electrical cross-connect (EXC) no optical bypass transparent (hybrid) intermediate grooming in EXC optical bypass using all-optical crossconnect (OXC) or optical patch panel (OPP) EXC EXC OXC/OADM/OPP transponder/ col. line card

13 Optical node design Range of technologies, each giving different architectures 3D MEMs switches Wavelength selective switches Simplest example is degree 2 ROADM Higher degree components available this year Technologies include MEMs, piezo-mechanical, planar waveguide Alternatively reduce the cost of OEO transponder technology

14 OEO A B D EXC Client side C Large EXC very flexible Lots of transponders (OEOs) Requires cheap integrated OEOs to scale

15 ROADM A B D ROADM EXC From A From B From C Client side C Available now Provides node bypass for linear DWDM chains Reduced OEOs Works best for static / predictable traffic growth

16 Matrix OXC A B D OXC Client side C Optical equivalent of trad EXC very flexible Large OXC won t scale if 1 λ per port Wavelength banding helps Few transponders (OEOs)

17 WSS A B D WSS Client side C Less flexible but gives sufficient λ access? Scales better than previous Few transponders (OEOs) New technology Most cost effective optics solution for the future (?)

18 BT Metro Network Study Technology Loss Comparison Total Thru Path Loss Add Path Loss Drop Path Loss Loss (db) Waveblocker Passive Add & Drop 1x9 WSS Active Add & Passive Drop 1x9 WSS Active Add & Drop Matrix Switch Technology

19 Dynamic traffic If traffic static and growth predictable we can design network perfectly tailored in advance no need for flexible all-optical network How dynamic will the real network become? Traffic growth unpredictable but if we build static network infrastructure, growth will economically be driven the same way As traffic volume grows there will be large numbers of wavelengths in the core, and the need to switch them quickly and flexibly will increase Flexible network can provide wavelength services anywhere Any time instant provision allows time of day services (e.g. large back up of company data) Fast response to multiple network failures. Far less required protection bandwidth (optical mesh restoration)

20 Network Design Cost Analysis (1) BT Core Normalised Cost O-E-O (Fully Provisioned Transponders) O-E-O (Transp. Dimensioned to Static Paths) MEMS Matrix Waveblocker WSS (Active Add, Passive Drop) WSS (Active Add & Drop) Technology Transponders Utilised Network Spare Network

21 Network Design Cost Analysis (3) BT Core Normalised Cost Base 3x 5x Traffic Scenario O-E-O (Fully Provisioned Transponders) MEMS Matrix WSS (Active Add, Passive Drop) O-E-O (Transp. Dimensioned to Static Paths) Waveblocker WSS (Active Add & Drop)

22 Conclusions Two key advantages for all-optical core networks: Economic savings CAPEX and possibly OPEX Increased network flexibility But for static (or slowly growing) traffic ROADMs deliver most of the node bypass savings And we can have greater flexibility from electronics (e.g. sub rate grooming) OEO costs could potentially reduce via photonic integrated circuits And all-optical networks are all-analogue networks Problems with optical transients, optical performance monitoring, channel setup So will we need dynamic traffic at the wavelength level? If so there are a range of architectures worth considering Wavelength Selective Switches appear to be the cheapest and most easily scalable

23 Network Design Cost Analysis (2) BT Core Normalised Cost Base 3x 5x Base 3x 5x Base 3x 5x Base 3x 5x Base 3x 5x Base 3x 5x O-E-O (Fully Provisioned Transponders) O-E-O (Transp. Dimensioned to Static Paths) MEMS Matrix Waveblocker WSS (Active Add, Passive Drop) WSS (Active Add & Drop) Technology & Traffic Scenario Transponders Utilised Network Spare Network