MEMS and its ApplicationsOptical Routing, an example

Shashi MysoreComputer ScienceUCSB

Outline• MEMS

– Introduction, application, fabrication

• Generic router– Features and drawbacks

• Optical Solution• Optical Router Projects

– Stanford 100Tbps

• Lucent LambdaRouter• GMPLS light path setup

What is MEMS?

• Micro-Electro-Mechanical Systems

• integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate

Generic System abstraction

ProcessInput Output

What’s challenging? The input, output, processing elementsare almost so varied that they are manufactured differently

Interfacing problem – speed mismatch, transferring signal is difficult

MEMS Applications

Medical Applications

Micro-fabrication

• Micromechanical components – micromachining• IC process

MEMS Manufacturing

Micromotor Fabrication exampleMicromotor Fabrication Example

MEMS devices

Scale comparisonCisco GSR 12416

Juniper M160

6ft

19”

2ft

Capacity: 160Gb/sPower: 4.2kW

3ft

2.5ft

19”

Capacity: 80Gb/sPower: 2.6kW

Whirlwind (1940)

Technology Trend and RoadmapTechnology Trend and Roadmap

Mems patents issued per year

MEMS in today’s Networks

Outline• MEMS

– Introduction, application, fabrication

• Generic router– Features and drawbacks

• Optical Solution• Optical Router Projects

– Stanford 100Tbps

• Lucent LambdaRouter• GMPLS light path setup

Generic Router Architecture

LookupIP Address

UpdateHeader

Header Processing

AddressTable

AddressTable

LookupIP Address

UpdateHeader

Header Processing

AddressTable

AddressTable

LookupIP Address

UpdateHeader

Header Processing

AddressTable

AddressTable

BufferManager

BufferMemory

BufferMemory

BufferManager

BufferMemory

BufferMemory

BufferManager

BufferMemory

BufferMemory

Switch Fabric

LinecardsLinecards

Performance trendsRelative performance increase

1

10

100

1000

1990 1992 1994 1996 1998 2000 2002

Router capacityx2.2/18 months

DRAM access rate x1.1/18 m

Moore’s lawx2/18 m

Relative performance increase

0

200

400

600

800

1000

1200

2002 2004 2006 2008 2010 2012

Internettraffic x2/yr

Router capacityx2.2/18 months

5x

Relative Performance Increase

All-optical networks•An all-optical network is one in which information is carried via light particles – or photons - from PC to PC, without ever having to be converted to electrical signals

OEO conversions are costly

• Electronic switches have managed to keep up with increasing bandwidths;

• Data sent increasing twice as fast as the routing capacity

• However, Optical-Electrical-Optical conversions are costly!

Data storage in optics

• Data storage is a critical problem for an optical router.

• Optical solution - Bell Laboratories’ photonic IC keeps optical signals circulating around within the chip

Optical Router projects

• Stanford 100Tbps Optical Router – Optical switching and Communications System

Laboratory

• UCDavis, UCSC, Colorado University, etc, • $12.5 million grant from DARPA for Lucent Bell

Labs

• "The result of this work will be a scalable prototype system that will digitally manipulate optical beams, like radio beams are manipulated

today, enabling better communications over farther distances," -Mike Geller, vice president of Lucent's Government Communications Lab.

Arbitration

160Gb/s

160Gb/s

SwitchFabric

• Line termination

• IP packet processing

• Packet buffering

• Line termination

• IP packet processing

• Packet buffering

160-320Gb/s

160-320Gb/s

Electronic

Linecard #1ElectronicLinecard #625

Request

Grant

(100Tb/s = 625 * 160Gb/s)

Stanford 100Tb/s router project

Racks with 160Gb/s linecards

DRAM DRAM DRAM

Queue ManagerSRAM

Lookup

DRAM DRAM DRAM

Queue ManagerSRAM

Lookup

100Tb/s Router

Optical SwitchFabric

Racks of 160Gb/sLinecards

Optical links

Passive Optical Switching

1, , n

1, , n

1, , n

1 1

2 2

n n

1, , n

1, , n

1, , n

1

2

n

MidstageLinecard 1

MidstageLinecard 2

MidstageLinecard n

IngressLinecard 1

IngressLinecard 2

IngressLinecard n

1, , n

1, , n

1, , n

1, , n

1, , n

1, , n

1

2

n

EgressLinecard 1

EgressLinecard 2

EgressLinecard n

1 1

2 2

n n

Integrated AWGR ordiffraction grating based wavelength router

Outline• MEMS

– Introduction, application, fabrication

• Generic router– Features and drawbacks

• Optical Solution• Optical Router Projects

– Stanford 100Tbps

• Lucent LambdaRouter• GMPLS light path setup

Lucent LambdaRouter

• Density - 250 micro mirrors fit on a one-square-inch chip

• Compact switching fabric - 32 times greater switching density

• Tilting mirrors - individual wavelength can be passed to any of 256 input and output fibers.

• Power reduction – upto 100-fold over electronic fabric solutions.

• “Instant Internet" and other high-speed data and video services

• "As communications networks evolve, optical technology will be at the core of these networks and make its way out toward the edges -- bringing unlimited capacity and speed to the desktop and someday, even the home,"

Micro mirrors

Routing light throughMicro mirrors

LambdaRouter

LambdaRouter with a shared pool of wavelength converters

Multiple bi-directional fibresInterconnect LambdaRoutersIncoming signals demultiplexedOptical Switching Outputs are wavelength multiplexed

Beware of wavelenght collisions!

GMPLS Lightpath setup

• Data plane – all optical

• Optical layer control plane – required to provision lightpaths

• Use GMPLS to solve the problem?– Call blocking probability metric

RSVP-TE Lightpath Setup

GMPLS - Wavelength converters

GMPLS – Crankback feature

Challenges in MEMS technology

• Advanced Simulation and modeling tools

• Packaging needs improvement

• Though started in 1960s, the amount of R&D investment has begun only in the past 10 years

• Multidisciplinary study

Thanks

• Some slides/figures borrowed from Stanford 100Tbps project, Colorado University presentation, Bell Labs, and news articles