photonics21 – next-generation optical internet access: roadmap for broadband optical internet...

Photonics21 Next Generation

Optical Internet Access:Roadmap for Broadband Optical Access towards 10Gb/s

Everywhere

Dr Kyeong Soo (Joseph) Kim (k.s.kim@swansea.ac.uk)

Institute of Advanced Telecommunications

Outline

• Swansea & Swansea University

• TSB Photonics21–NGOIA Project

– Business & Architectural Issues

– Paradigm Shift in Optical Networking

– Ultimate Optical Network Architecture

– Toward Next-Generation Optical Access

• Summary

SWANSEA & SWANSEA

UNIVERSITY

Where is Swansea?

WalesSwansea Cardiff - Welsh Capital

Less than an hour away

by car or train

London – UK Capital

Less than three hours

by car or train

(192 miles)

Swansea University

•29th university

established in the UK

•King George V laid the

foundation stone in July

1920

•Now over 12,000

students

–1,800 international

Swansea University

The University stands in parkland overlooking Swansea Bay on the edge of

the Gower Peninsula, Britain's first “Area of Outstanding Natural Beauty”.

Beach

World-Class Research

• Why should you be interested in research?

• 4 world-class research centres

• 5* research ratings – one of only 3 in the UK

• Strong links with industry E.g. Rolls Royce,

Siemens, IBM, Esso, BP Chemicals, Ford,

BT, Procter and Gamble

• Many of our industrial partners offer

sponsorship and prizes

• Recent research projects have included:

Millennium Stadium, Supersonic Thrust Car

• 3 world-class research centres

• Civil and Computational Research Centre

• Materials Research Centre

• Multidisciplinary Nanotechnology Centre

• Within top 8 Eng. Dept. in the UK

• Strong links with industry

• NASA, Rolls Royce, Airbus, European Space

Agency, BAE systems, Siemens, IBM, Motorola,

BT, Ericsson, Esso, BP Chemicals, Texaco, Ford,

Procter and Gamble, Corus, …

• Recent research projects including

• Millennium Stadium, Supersonic Thrust Car,

Airbus A380, NASA space shuttle, …

World-Class Research

Scholarships

• Zienkiewicz Scholarships (MRes, PhD)

– Full fees plus generous stipend

• Erasmus Mundus MSc in Computational Mechanics

– Worldwide cooperation and mobility programme

– €42,000

• School of Engineering Scholarships

– For both undergraduate and postgraduate

TSB PHOTONICS21–NGOIA PROJECT

Aim

• To identify promising routes forward in achieving the

goal of “10 Gb/s everywhere”, while making best use of

the existing knowledge that has been gained in earlier

projects.

– The solutions will show most promise of cost

effectiveness, be future proof (i.e., allowing

bandwidth evolution and infrastructure reuse) and

allow simple interfaces which can be standardized.

Partners

• 5 Industrial Partners

– Oclaro (Bookham)

– BT

– Ericsson

– CIP

– Gooch & Housego

• 4 Academic Partners

– Cambridge

– Essex

– Swansea

– UCL

Target FP7* ICT Work Programme 2009-10

• Objective ICT-2009 3.7: Photonics: €60M

– Photonics21** ERA-NET*** Plus: €10M

• On the FTTH broadband infrastructure providing

1 Gb/s data rates for every household, scalable

to 10 Gb/s.

* FP7: the Seventh Framework Programme for Research and Technological Development

** Photonics21: A European Technology Platform

*** ERA-NET: European Research Area-Network

BUSINESS & ARCHITECTURAL

ISSUES

FTTH* vs. Cloud Computing**

SaaS*** User

SaaS Provider/

Cloud User

Cloud Provider

Web Apps

Utility computing

vs.

* NGOA Workshop, Mar. 2008.

** “Above the clouds”, UC Berkeley.

*** SaaS: Software as a Service

FTTH Business Perspective*

Layer Economic

Character

Life Cycle Cost per

Subscriber

Service Layer Low CapEx,

average to high

OpEx

1 to x years ?

Active Layer Average CapEx,

low OpEx

5 to 10 years €300~500

Passive Layer High CapEx, very

(very) low OpEx

25 to 50 years €500~700

•NGOA Workshop, Mar. 2008.

Cloud Computing: New Aspects in Hardware*

• The illusion of infinite computing resources available on

demand

– Through the construction of large-scale, commodity-computer

datacenters at low cost locations, and virtualization technique

• The elimination of an up-front commitment by Cloud users

– Companies can start small and increase gradually

• The ability to pay for use of computing resources on a

short-term basis as needed* “Above the clouds”, UC Berkeley.

Cloud Computing: Economic Benefits*

• Elasticity

– Ability to add or remove

resources at a fine grain

and with a small lead time

• Transference of risks of

– Overprovisioning

(underutilization)

– Underprovisioning

(saturation)

* “Above the clouds”, UC Berkeley.

Max. (=peak)

Min.

Avg.

Time

Demand

Cloud Computing: A New Killer Application for

Next Generation Optical Internet Access?

• Data transfer bottlenecks (to and from Clouds)

– Example: Move 10 TB from UC Berkeley to Amazon in

Seattle*

• WAN link of 20 Mb/s: 4 Msec ≈ 46 days

• Overnight shipping (FedEx): 1 day (i.e., 1.5 Gb/s)

• 10 Gb/s link: ≈ 2 hours

» Even better if we could use more than 10

Gb/s for a short period!

* “Above the clouds”, UC Berkeley.

ULTIMATE OPTICAL NETWORK

ARCHITECTURE

Current Network Limitations

• Bandwidth-hungry services (e.g., VOD, IPTV):

– Increase the amount of network infrastructure

– Increase the network energy consumption

– Increase the data-driven network crashes

• Due to:

– Unbalance in capacity between core and access

– Mismatch between service/usage models and network

infrastructure

– Large number of power-hungry and error-prone electrical

components/systems

Paradigm Shift in Optical Networking

• Changes in network architectures

– Performance Energy efficiency driven

– Static Dynamically reconfigurable network

– Dedicated Shared resources

– Separate & complicated Integrated & simplified management layers/interfaces

– Unbalanced Balanced bandwidth link utilization

Traditional Way of Using Wavelengths

TX

TX

TX

TX

RX

RX

RX

RX

SW SW

Optical Network with

Passive/Semi-passive Nodes

New Way of Using Wavelengths

Tunable

TXSW

Tunable

TXSW

Tunable

TXSW

Fixed

RXSW

Fixed

RXSW

Fixed

RXSW

Continuous vs. Burst-Mode Communications

TX RXSW SW...010110100101110100101001001010101111101001010101…

SONET/SDH

Packet Packet Packet

RX SW10011…0110

Packet Packet Packet

011…010 011…010

Enabling Technologies

• Common denominator in technologies enabling

flexible, dynamically-reconfigurable optical networks

– CWDM

– Tunable filters

– Tunable lasers

– Burst-mode communications

• The paradigm shift pushes these technologies

towards the edge of the networks!

Ultimate Optical Network Architecture - 1

• A common network architecture/infrastructure for access/metro/backbone

• To enjoy the benefits of Economy of Scale* by maximizing statistical MUXing gain over

– Traffic burstiness

– Different usage patterns

• Challenge: How to integrate them all?

27

Backbone/CoreBackbone/CoreMAN

Access

Access

Residential

Users

Business

Users

Access/MAN/Backbone

Residential

Users

Business

Users

* Factors of 5 to 7 decrease in cost (“Above the clouds”, UC Berkeley)

Ultimate Optical Network Architecture - 2

• Network resource as utility

• Cut the (static) link between fibre infrastructure and pool of transceivers

• Challenge: Everything (both up- and downstream) in burst-mode communications

28

Fibre Infrastructure

(Access/MAN) …

Transceivers

X

Ultimate Optical Network Architecture - 3

…

…

…

…

… …

…

P-T-P & WDM-PONTDM-PON

Hybrid PON(with advanced architecture)

Ultimate Optical Network Architecture:

Example

SUCCESS-HPON – Hybrid TDM/WDM-PONs

(2003-2005)

Central

OfficeRN

RN

RN

RN

’1, 2

1

2

21

22 23

’1

’3, 4, …

1, 2

3, 4, …

3

’3

3

31

32

33

TDM-PON ONU

RN TDM-PON RN

WDM-PON ONU

RN WDM-PON RN

Central

OfficeRN

RN

RN

RN

’1, 2

1

2

21

22 23

’1

’3, 4, …

1, 2

3, 4, …

3

’3

3

31

32

33

TDM-PON ONU

RN TDM-PON RN

WDM-PON ONU

RN WDM-PON RN

Protection & restoration is

possible by using different s

on east- and west- bound.

Benefits of Flexible Architecture

R

Tunable

TX 1

Power

SplitterWDM

DEMUX

ONU 1

ONU 16

. .

.

Start small and grow gradually

Benefits of Flexible Architecture

R

R

Tunable

TX 1

Tunable

TX 2

Power

SplitterWDM

DEMUX

ONU 1

ONU 32

. .

.

Start small and grow gradually

Benefits of Flexible Architecture

R

R

Tunable

TX 1

Tunable

TX 2

Power

SplitterWDM

DEMUX

ONU 1

ONU 48

. .

.

R

Tunable

TX 3

Start small and grow gradually

Benefits of Flexible Architecture

R

R

Tunable

TX 1

Tunable

TX 2

Power

SplitterWDM

DEMUX

ONU 1

ONU 64

. .

.

R

Tunable

TX 3

R

Tunable

TX 4

Start small and grow gradually

Benefits of Flexible Architecture

R

R

Tunable

TX 1

Tunable

TX 2

Power

SplitterWDM

DEMUX

ONU 1

ONU 64

. .

.

R

Tunable

TX 3

R

Tunable

TX 4

Flexibility and power efficiency

Usage = 50%

(Compared to Peak)Turn off TX3 & TX4 to save energy

Benefits of Flexible Architecture

R

R

Tunable

TX 1

Tunable

TX 2

Power

SplitterWDM

DEMUX

ONU 1

ONU 64

. .

.

R

Tunable

TX 3

R

Tunable

TX 4

Redundancy and hot-swap capability

TX4 failedThe system is still running (with

slightly degraded performance)

TOWARD NEXT-GENERATION OPTICAL

ACCESS

Evolution of Optical Access

OLT

ONU

ONU

ONU

OLT

ONU

ONU

TDM-PON

OLT

ONU

ONU

ONU

ONU

OLT

ONU

ONU

ONU

? LR-PON

WDM-PON

Hybrid PON

Geneva, 19-20 June 2008

Evolution scenario

Now ~2010 ~2015

Power splitter deployed for Giga PON(no replacement / no addition)

Splitter for NGA2(power splitter or something new)

G-PON

GE-PON

WDM option to

enable to overlay multiple G/XGPONs

Co-existence

“Co-existence”arrows mean to allow gradual migration in the same ODN.

NG-PON2E.g. Higher-rate TDM

DWDMElect. CDMOFDM,Etc.

Equipment

be common

as much as

possible

NG-PON1 incl. long-reach optionC

apacity

XG-PON(Up: 2.5G to 10G,

Down: 10G)

Co-existence

Component R&D to enable NG-PON2

A Suggested Time Line from ITU-T/IEEE*

* J. Kani and R. Davey , “Requirements for Next Generation PON,”

Joint ITU-T/IEEE Workshop on NGOA, Jun. 2008.

Areas of Improvement

• Reach– Through amplification

• Bandwidth per subscriber– Higher transmission rate in TDM-PON

– Introduction of WDM

• User base– Serving both residential and business users

through common infrastructure• Stronger protection capability for business users

Candidates for NGOA

• LR-PON

– 10 Gb/s over 100km with up to 1000:1 split ratios*

• WDM-PON

– Use of array of transceivers

– Lack of BW sharing

– Inventory management of ONUs with different s

– Need of colorless or sourceless ONUs

• Hybrid TDM/WDM-PON

– Use of fast tuneable lasers (and receivers)

– Flexible architecture, but complex MAC/scheduling

– How-swapping capability of tuneable components

* MIT CIPS Optical Broadband Working Group

Challenges

• Power Efficiency

– Number of high-powered transceivers and optical amplifiers in use

• Maintenance

– For active components and thermal optical devices in the field

• Backward compatibility

– For current-generation TDM-PONs

• Scalability

– Start small and grow gradually

• Integration with other services

– Wireless/Video overlay

43

BT’s Current

UK Network

BT-21CN

Simplified UK

Network

Current Status of Network

Excerpts from Architecture Document

• “10 Gbit/s everywhere” is taken to mean that any customer premises can

cost-effectively access useful end-to-end symmetrical throughputs of

10Gb/s data on demand (i.e., whenever they want it but it need not

necessarily always be there).”

– Major focus on residential and SME customers.

– 10 Gb/s line rate in the access is a necessary but not sufficient condition.

– Some degree of contention assumed at various points in the network

• What is missing here?

– Description/definition which is

• Specific (e.g., What is “useful”?)

• Practical & implementable (e.g., any shared architecture can achieve this?)

• Measurable (during the operation in the field)

What Does “10 Gb/s” Means?

• We need a quantifiable &

measurable definition of “10 Gb/s” at

the user side for

– Comparative study of candidate

architectures

– Actual implementations

• One proposal is based on the

extension of the equivalent circuit

rate (ECR)*.

– For general services & applications

in addition to web-browsing and

interactive data

– Taking into account access/metro

part only* N.K. Shankaranarayanan, Z. Jiang, and P. Mishra,

“User-perceived performance of web-browsing and

interactive data in HFC cable access networks,” Proc. Of

ICC, pp. 1264-1268, Jun. 2001.

Server

User

User

Candidate architecture

Server User

User

Y

Z = α*min(X, Y) (α < 1)

The same

perceived

performance

X

Implications on Metro/Access* Architectures - 1

• If we mean by “10 Gb/s” the (extended) ECR of

the network architecture (i.e., Z), we can derive

the following conclusions:

– Point-to-point (including static WDM-PONs)

architectures with a UNI (i.e., Y) of 10 Gb/s can meet

the requirement.

• As far as the NNI (i.e., X) is not a bottleneck.

• But there is no statistical multiplexing gain (i.e., sharing of

resources) in this architecture.

* Not end-to-end.

Implications on Metro/Access Architectures - 2

– Shared architectures with a UNI of 10 Gb/s may not meet this

requirement (i.e., ECR < 10 Gb/s), irrespective of NNI.

• Need to increase either line rate (for TDM-PON & hybrid

TDM/WDM-PON) or number of WDM channels (for hybrid

TDM/WDM-PON) at the UNI.

• Note that the ECR is a function of the architecture (fixed

component), the number of users, and the nature of

services/applications (variable components).

» Possible (& even desirable?) to keep the ECR constant

(i.e., 10 Gb/s in this case) by changing the line rate

and/or the number of WDM channels?

Summary

• Changing business environment and demands are driving forces behind the paradigm shift in optical networking toward

– Flexible, dynamically-reconfigurable network to better utilize network resources

– Passive/semi-passive network to maximise energy efficiency

– A common network infrastructure for access/metro/backbone

• We plan to carry out the following tasks for realizing NGOIA solutions scalable up to 10 Gb/s:

– Investigate candidate architectures in terms of cost, power efficiency, maintenance, scalability, and extensibility.

– Provide a guideline for future NGOIA solutions and large-scale European projects on this subject.

Questions?

Thank you for your time