Paul Lagasse

Dept. of Information TechnologyGhent University

OPTICAL NETWORK EVOLUTION

IST May 2001

MJO’Mahony, Univ. of Essex

Technology DriversGlobal Area Network

Wide Area Network

Metropolitan/Regional Area Optical Network

Corporate/Enterprise Clients

GAN• Capacity 10 Tb/s/fibre (2015)• Max transmission speed 100 Gb/s• Unregenerated distance > 10,000 km

WAN• Capacity 2.5-40 Tb/s/fibre• Max transmission speed, 40 Gb/s• Unregenerated distance 3000 km• OXC: >5000 x 5000

MA(O)N• Capacity: ?• Distance: 20-200 km• OADM Dimensions:?

Client/Access

• Integrating IP&Backbone (control)• Gigabit Ethernet:

• low cost WDMServices• Fast provisioning

Cable modemNetworks

Client/Access Networks

FTTH

Mobile

SDH/SONET

ATM

PSTN/IP

ISPGigabit Ethernet

Cable

FTTB

ATM

WDM / OTN

SDH

ATM

IP

Pt to Pt WDM

FRAMING

IPMPLS

-networking

Network Evolution

Telscom Consulting, Switzerland

IP over Intelligent Optical Networks

Establish high-speed optical layer connections (lightpaths)

IP routers connected through lightpaths rather than fiber

Switching (WDM crossconnects) add flexibility to the optical layer

Flexible, potentially rich, topology at IP layer

A

B C

D

E W a v e le n g thc ro s s co n n e c t

L ig h tp a th s

IP ro u te r

MJO’Mahony, Univ. of Essex

Global Area Network

• Capacity 10 Tb/s/fibre (2015)• Max transmission speed 100 Gb/s• Unregenerated distance > 10,000 km

Technology Issues:

Transmission options: OTDM+WDM100 nm amplification band Raman +C (1540 nm) +L (1580) bands

128 channels (100 Ghz spacing)100 Gb/s per channel

Key Component & Subsystems: Optical amplifiersDispersion compensation (over 100 nm)

Other issues: Trade off between channel speed and wavelength numberLinear/Non-linear transmission

MJO’Mahony, Univ. of Essex

WAN Network

OXC• Capacity 2.5-40 Tb/s/fibre• Max transmission speed, 40 -? Gb/s• Unregenerated distance 3000 km• OXC: >5000 x 5000

Technology Issues:

Network level: Optical circuit switching (wavelength routing)Optical packet switching

Transmission options: OTDM+WDM40 Gb/s per channel1000 channels

-400 nm amplification band 1250-1650 nm 1000 channels (50 GHz spacing)

NB: for WAN more channels at lower bit rate gives greater flexibility

Key Component & Subsystems: Optical amplifier configurations for 400 nmOXC: 1000 wavelengths x 30 (?) fibres = 30000x30000

-thus new multilevel architecture necessaryMulitplexers/demultiplexers (for 1000 channels)Wavelength convertersTuneable lasers

MJO’Mahony, Univ. of Essex

Metropolitan Area Optical Network

WAN

Client/Access

Network level: wavelength division multiplexing/wavelength accessaccess protocol?

Transmission options: WDM2.5-10 Gb/s per channel1000 channels

-400 nm amplification band 1250-1650 nm 1000 channels (50 GHz spacing)

NB: for WAN more channels at lower bit rate gives greater flexibility

Key Component & Subsystems: Low cost componentsOADM

MA(O)N• Capacity: ?• Distance: 20-200 km• OADM Dimensions:?

Telscom Consulting, Switzerland

Evolution: Copper TPs

WAN

SN

SN

SNSTM-4/16 speed level

ADM Add Drop MultiplexerADSL Asymmetric digital subscriber LineISDN Integrated Services Digital NetworkOADM Optical access multiplexerOANT Optical Access Network TerminationOXC Optical Cross ConnectSN Service NodeSOHO Small Office, Home OfficeVDSL Very High Speed Digital Subscriber LineWAN Wide Area Network (all fiber)

STM-64+ speed levelDWDM

Optical AccessNetwork

OANTFTTB/H

GatewayRouter

Regional / Metro

LargeEnterprises

Service InterfacesHouse WiringLANs

Medium BusinessesSOHOResidential

OADM

OXC

OADM

OADMOANTFTTC

GatewayRouter

VDSLPOTS, ISDN

UTP-Cable

UTP-Cable

Telscom Consulting, Switzerland

Coax Cell

Evolution: Coax Cable, HFC

OpticalAccess Network

CATVBack Bone

WAN

Regional / Metro(Data Back Bone)

Digital&

AnalogHFC

Head-end

STM-4/16 speed level

CATV Cable TelevisionCGW Coax Gate WayCM Cable ModemCMT Cable Modem TerminationHFC Hybrid Fiber CoaxOADM Optical Add Drop MultiplexerOANT Optical Access Network TerminationOXC Optical Cross ConnectSN Service NodeSOHO Small Offices, Home OfficesWAN Wide Area Network (all fiber)

STM-16/64 speed levelDWDM

Coax Cell

CGW

CM

LargeEnterprises SN

SN

SN

Coax Cell

Digital&

AnalogOANT

Digital&

AnalogOANT

Digital&

AnalogOANT

CGW

CGW

CGW

CGWCGW

Coax5 to 1000MHzDownstream:FDM (AM VSB, QAM)Upstream:FDMA/TDMA (QAM)

ServiceInterfacesHouse WiringLANsB

road

cast

Ser

vice

s

CGW

Residential

Medium BusinessesSOHO

Residential

Data Modems (CMTs) moving to the OANTsFrequency Reuse in the Coax Distribution Cells

OXCRouter

OADMRouter

OADMRouter

OADMRouter

Telscom Consulting, Switzerland

Passive Optical Network PON

ODNd1, d2,... dNd1, d2,... dN

u1, u2,... uMu1, u2,... uM

di, uk fixed/config.

dq, ur fixed/configurable

d, u variableRegional

Metro

OLTRXRXRXRXRX

TXTXTX 4

TXTX

RX1

TX1

Demux

Mux

TX

RX OANTMux

Router

TX

RX OANTMux

RouterTP-Cable

VDSLPOTS, ISDN

FTTBuildingIn_House Network / LAN• Medium Businesses• SOHO• Residential

FTTCurb• SOHO• Residential

FTTBuilding/DesqueIn-House Network / LAN• Enterprises• Big Businesses

ADM Add Drop MultiplexerADSL Asymmetric digital subscriber LineISDN Integrated Services Digital NetworkNTU Network Termination UnitOANT Optical Access Network TerminationODN Optical Distribution NetworkOLT Optical Line TerminationSOHO Small Offices, Home Offices

OANTMux

RouterTX

RX

Downstream: TDM / (D)WDM

Upstream: TDMA / (D)WDM

In-HouseNetwork

NTU

Layer 1, 2 and 3

Telscom Consulting, Switzerland

ActiveStar Coupler

Passive Optical Star Network (LAN)

TXsd

RXsu

ControlNode

OpticalTerminal

1

OpticalTerminal

2

OpticalTerminal

n

RX

(i=1,...n)

su + 2

passive optical Combiner

passive optical Splitter

optical amplifier3R-Regeneration

RX

TX1

TX2

TXn

RX

su + 1

su + n

1000BaseLX/SX/CX10’000BaseLXIPLayer 1, 2 and 3

ControlChannels

su

sd

sd + i

sd + i

sd + iRegional / Metro

OSI Model Layers:1 Physical2 Data Link (Including Medium Access Control) 3 Network (e.g. IP Address Resolution Protocol

ARP, Routing, “Distributed Ultra High Speed Router”)

Telscom Consulting, Switzerland

Optical Ring / Star Network

I/O1

Mutliplexer

RX

TX RX

TX

I/O2

I/ON

AccessInterfaces

1

2

3 45 6

7 8

1, 2 Transfer3, 4 Drop5, 6 Add7, 8 Loop Back (Restoration)

AN

AN AN

AN

AN

AN

Access Network

Regional / Metro

UT

P-C

ableAN to the Building

• Enterprises• Big Businesses

FTTBuilding / Active Star:

FTTCurb / DSL• SOHO• Residential

UT

P-C

able

• Medium Businesses• SOHO• Residential

Fiber or Copper

Ultra high bit rate transmission experiments

1010

20

20

50

50

100

100

Single Channel B it Rate (Gbit/s)

200

200

500

500

1000

1000 2000

2000

5000

10000

20000

Tota

l Bit

Rat

e (G

bit

/s)

TDM

W DM

20G x 5

10G x 25

11G x 1610G x 16

10G x 8410G x 50

10G x 73

10G x 100

20G x 32 100G x 10

80G x 13200G x 7

640G

1280G

32G40G

80G100G

200G

160G

400G

160G x 1940G x 82

40G x 160

20G x 132

20G x 16011.6G x300

42 .7G x25640G x273

20G x 55

100G x 4

40G x 30

20G x 50

20G x 17

40G x 4

20G x 11

1 Tbit/s

Up to 199 9O FC ’ 200 0EC O C ’20 00O FC ’2001

Source: LEOS Newsletter 10/99, OFC‘2000, ECOC‘2000, OFC‘2001

Component technologies and trends

Emerging componenttechnologies

Packet switched optical networks

Point-to-point systems

Wavelength converters

Routers

Switches

3R repeaters

Dispersion compensators

Receivers

Light sources

Fibers

Amplifiers

Optical buffers

Circuit switched optical networks

Wavelength conversion and regeneration - example

Input signal

SOA

SOA

CW

Output signal

Regeneration and wavelength conversion obtained - conversion over 80 nm possible

Regeneration and wavelength conversion @ 40 Gbit/s

Emerging component technologies

Emerging component technologies

Microoptics andNanoelectronics• MOEMS• Photonic bandgap devices• Quantum dot devices• Carbon nanotubes

Polymeroptoelectronics

Quantum Communication• Cryptography• Computing• Teleportation

MicroOptoElectroMechanical Systems (MOEMS)

Characteristics of MOEMS

Size: microns to mm scale

Speed: 100 ’s of nanoseconds to 1s

Scalability: 1 to 106 components

What is the MOEMS ?

Cost: cost of chip + assembly/package

Optical

Electrical Mechanical

Electro-Optical

Opto-Mechanical

Electro-Mechanical

MOEMS

Actuation energy: CV2/2(electrostatic)

k

Normalised wavevector k/20.5

Bandgap

Nor

mal

ised

fre

quen

cy

c1-D periodic structure

Band diagram

Waves in periodic structures

Photonic bandgap structuresfor compact photonic ICs

Schematic diagram of a photonic bandgapwaveguide

SEM picture of a PBG waveguide in silicon-on-isolator

From IST project PICCO

PBG-waveguides

Numerical calculation of anelectromagnetic field propagating in a T-shaped PBG waveguide

T. Sondergaard and K. Dridi, Phys. Rev. B, Vol. 61, p. 15688, 2000