Smart Light for Ubiquitous Communications Thomas Little Associate - - PowerPoint PPT Presentation

Smart Light for Ubiquitous Communications

Thomas Little Associate Director NSF Smart Lighting Engineering Research Center 05-21-2009

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The Smart Lighting ERC

• Fundamental advancements in solid-state devices – LEDs – that

enable a wide range of new applications in

• Bio-imaging
• Indoor communications
• Outdoor communications / transportation
• Display technologies
• The plan: exploit the strength of the team
• Novel materials
• Devices
• Downstream systems
• Strong commitment to education, supporting underrepresented

groups, facilitating technology transfer

• 10 years > $18M from National Science Foundation
• > $50M via supplementary university, state, industry

Boston University role - applications in communications and networking “Visual Light Communications”

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Why did we get funded #1?

To develop ‘controllable’ light and its down-stream applications Controllability is an enabler Downstream apps define the ‘systems pull’

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Controllability is important for

Dynamic and adaptive lighting

For architectural use For improving visibility For imaging For health benefits

Modulation – for communications Power control

For energy management

Why relevant

Control over the end consumer: lighting Lights that are individually addressable and controllable Environments that are adaptive to occupants And networked enabled

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So why did we get funded? #2

Huge potential savings by the adoption of LED lighting

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Comparison

Incandescent

$0.65/bulb 15 years of electricity: $72.55 1000-2000 hours of life

LED

$120/bulb 15 years of electricity: $9.67 20,000-50,000 hours of life

CFL

$4/bulb 15 years of electricity: $18.14 6,000-12,000 hours of life

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Clearly we need to reduce the device cost of LED lighting

Nat Geo March 2009

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Quantification of solid-state lighting benefits

Energy benefits

• 22% of electricity used for lighting
• LED lighting can be 20× and 5× more efficient than incandescent and

fluorescent lighting, respectively

• Reduction in energy consumption > 1020J (*)
• Barrels of crude oil not needed: 0.96 ×109 (*)
• Power plants not needed: 280 (*)

Environmental benefits

• Global warming: Reduction of CO2 emissions > 10 Gt (*)
• Acid rain: Reduction of SO2 emissions
• Mercury, Hg: Reduction of toxic Hg emissions / Hg in homes

Financial and economic benefits

• Reduction in electrical energy cost > 1012 $ (*)

(*) over 10 years, worldwide, see Schubert et al. Reports on Progress in Physics 69, 3069 (2006) Switzerland

CO2 ,SO2 , NOx , Hg, U Cause: CO2

Czech Republic

Cause: SO2

Antarctica United States

Cause: Waste heat and acid rain

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The Story…

We plan to replace all lighting with LED lighting LED lighting is driven by on-off cycling on the input We will modulate data in addition to controlling intensity levels (we’ll improve color and add color control) We expect data rates competitive with wifi for indoor use, and better for some applications (video streaming) We’ll make the lighting load controllable, adaptable, and far more efficient We’ll enable other devices in the “container” to exploit network access and controllability

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VLC: what it is

Synopsis

Modulated light Visible spectrum (you can see it) A la ship to ship Morse code Point to point in simplest form Illumination + communication in the dominant scenarios

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Time Intensity Observer Source

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Office Scenario

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BAN Loop Internet Physician Analysis Local control

< 100ms <10s <100s Time scale: Scope:

RFID Zigbee WPAN Localization GPS Epidemiology Privacy Aggregation Sensor Modalities Resource Allocation

Person Population Organ Group

Three Control Loops Computational Performance

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Home Scenario

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Auto replenishment with tagged items Internet access ble/DSL/Fiber Networked boiler/HVAC Wireless thermostat

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Home Gateway Opportunity

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Home Gateway

Home network

How:

• Optical
• RF
• PL
• CAT5
• Future

Access for

• Appliances
• Smart Lighting
• HVAC
• Computers
• Entertainment
• Personal Health care

Interface for

• Monitoring
• Control

Home Gateway is key component to accessing status and control of network-enabled devices Gaps?

• Multiple providers (utilities,

telecoms)

• Design for robustness
• Privacy

Utility side Customer side Load

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Prototypes

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Summary Points

Smart Lighting: An opportunity to embed networking

Low energy use Networking where there is illumination

Ubiquitous communication is an enabler

Mobile wireless devices, embedded networked sensors, RFID, WiFi hotspots, transportation Better data and control from/to the physical world

LED-based communication and networking has important advantages:

Bandwidth, bandwidth density Privacy--security, bypassing RF Ubiquity if piggybacked on lighting Unregulated spectrum Control

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ADDITIONAL SLIDES

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VLC: Where it Matters

• Deliver HD video to individual seats
• Airbus holds > 500 people; HD requires 13 Mb/s; short range

personal lighting/communication for channel isolation; copper is

• heavy. High bandwidth density (>10 Mb/m3)
• Localized communication between vehicles
• Emerging safety-oriented technology: active braking, traffic

monitoring; warning message propagation.

• Directional transmission, PRF < 1%, < 100ms latency
• Indoor localization
• Finding roaming patients and doctors in a hospital; RF techniques

can be problematic; lights can be uniquely modulated with ID; tagging bats; security in downlink channel. Data trickle.

• Providing opportunistic mobile access
• Hotspots wherever there is illumination. Ubiquity.
• Moving vehicles. Internet access
• Mesh networks

From Airbus (www.airbus.com)

Courtesy of Thomas Kunz

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Do We Need This?

• There is little demand for VLC today
• VLC is a technology looking for a problem
• VLC has potential primarily as an opportunistic medium
• Energy Neutral
• Challenge: can we provide a useful communications physical

layer

• That does not add significantly to cost of lighting?
• That is energy efficient?
• That supports a broad enough range of applications (low and high data

rates)?

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Bridging to LAN Access Point

Modified Linksys Router

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National Science Foundation Engineering Research Centers Program The ERC Challenge:

Create and sustain an integrated, cross-disciplinary research environment to advance fundamental engineering knowledge and engineered systems Educate a globally competitive and diverse engineering workforce from K-12, and higher education Join academia and industry in partnership to achieve these goals 20 year history of success New in ’08: strong emphasis on the initiation and development of new technology-related small businesses -- startups

Initiated proposal development in the spring of 2006…

36 direct participants 22 committed member companies 20+ indirect academic participants

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VLC transformational Impact

Human created lighting sources will be dual use for illumination and…

• communication
• control
• automation
• safety
• information access

enabled by ubiquitous smart lighting systems

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Energy and Intensity Today

Light Sources Typical Power Luminous Efficiency3 Luminous Output Incandescent 60W1 15lm/W 900lm Fluorescent 32W1 80lm/W 2560lm High-intensity discharge 400W1 100lm/W 40000lm LED 10W2 150lm/W4 1500lm

• 1. US Department of Energy (DOE) 2006 Solid-State Lighting Research and Development Portfolio; Multi-year program plan

(http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/ssl_multiyear_plan.pdf)

• 2. Let There Be Light (http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=1030972&isnumber=22144)
• 3. Solid-state lighting—a benevolent technology (Fred doc)
• 4. Assume 50% of theoretical maximum is achievable

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Deans Council: Deans of Engineering (RPI, BU, UNM) + VP Research (RPI)

Executive Leadership Group All Directors + ILO Education Advisory Board Diversity Committee Student Leadership Council Academic Policy Board EDUCATION, OUTREACH & DIVERSITY Director: Ken Connor Outreach Coordinator Pre-College Liaison Technical Leadership Team Testbed Leaders Thrust Leader Systems Integration Committee Academic Co-Chair: TBD Industry Co-Chair: TBD CORE RESEARCH Systems Thrust: Michael Shur Materials Thrust: Steve Hersee

Device Thrust: Partha Dutta

THRUSTS Smart Displays & Lighting Michael Shur

Bio-Imaging Testbed: Richard Cole, John Wen

Indoor Comm & Outdoor Transportation Testbed: Jeff Carruthers,Tom Little SYSTEMS TESTBEDS Innovation Partners Industry Advisory Board INDUSTRY LIAISON & INNOVATION ILO: TBD Industry Partners Central Lab Support Staff Scientific Advisory Board

FACULTY & STUDENT INVESTIGATORS AT CORE PARTNERS INSTITUTIONS, OUTREACH PARTNER INSTITUTIONS, INTERNATIONAL PARTNER INSTITUTIONS

K-12 Partners ADMINISTRATION Director: Diane Veros Financial Officer

• Admin. Specialist

ERC Organization Chart

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Use Cases Drive the “Systems Pull”

• 1. Increasing safety in

transportation with active braking

• 1. Reducing total cost of
• wnership in indoor

illumination and industrial automation by wire elimination

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Use Cases Cont.

• 3. Enabling densely-packed

indoor wireless video streaming (e.g., in airplane)

• 4. Providing ubiquitous

network access where there is human-created light (light=smarts [network/control/communicat ions])

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Why did we get funded #3?

Strength of the team – integration of materials, devices, systems as a whole.

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The Opportunity: Lighting Replacement

• Estimate based on 2000 Census (USA)
• 106M housholds/128M housing units
• 60 bulbs in my house
• Assume 50 on average
• 640M bulbs out there
• 7.6M private nonfarm establishments
• Assume 1000 bulbs each
• 7,600M bulbs
• 20.8M Nonemployer establishments
• Assume 50 each (small businesses)
• 104M bulbs
• Back of the envelope: 10 billion ‘bulbs’ in residential and

commercial dwellings/establishments suitable for upgrade

• Depending on type, 500M to 5B replaced each year due to failure

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The Opportunity: New Applications

• Vehicles: > 72M vehicles produced in 2007 worldwide
• 40% of 2008 models use LED in center brake lights (CHMSL)
• 10% for side brake lights
• LED headlamps in some models (Lexus LS 600h)
• Expected to be approx 200 (Ultra-bright) LEDs per automobile by

2020

• Benefits: faster rise and fall times (reaction times)
• Reduced power budget during braking, aesthetics…

www.lexus.com

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High Brightness LED Market Forecast

OIDA Global Optoelectronics Industry Market Report and Forecast: High Brightness LEDs, Jan 2009

Revenue and Forecast

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Many Scenarios

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Uni LOS Bi LOS Uni Diffuse Lighting Mobile units Hybrid Symmetric— Asymmetric

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But What about RF?

Attribute RF@2.4GHz LED Optical Advantage Security/Privacy Penetrates walls Does not penetrate walls, prevents snooping LED optical Available Bandwidth Capacity

Signals sent at same frequency can interfere with one another and thus, limited by contention; signals degrade from peak BW. Light can be directed – smart light sources can be tuned to adapt to different environments and narrow footprints LED optical

Cost of Additional Bandwidth Spectrum

Very high when available None (yet) LED optical

Interference

Self, other users on same frequency slows transmission speed, ISM sources Visible natural (sun) and man made light (non-LED lamps) slow transmission speeds

Varies Multipath fading

Destructive interference: RF waves bounce off conductive surfaces and arrive at different times and/or are out of phase Interference appears as noise. No signal cancelling. LED optical

Path Redundancy

Achieved with multiple access points Achieved with multiple LEDs LED optical

Transmission Speed

100 megabits per second deployed Comparable, but with reuse of volume for higher aggregate speed. LED optical

Estimated Comparative Cost <$20 <$2 (Based on IrDA)

LED optical

31 FSO communication can have significant benefits over RF

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LED Lighting Characteristics

Illumination – need ‘White’ light

• 1. Combine RGB LEDs

Combine three peaks, need to control More electronics but control 3 ways Green LED not bright nor efficient Need to balance intensities

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From Dutta, 2009

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LED Lighting Characteristics

• 1. UV LED plus RGB phosphors: UV stimulates RGB

peaks

• Slower response times
• 2. Blue LED plus yellow phosphor: blue and phosphor

spectrum Types

• High current (350mA)
• 50—140 lm/W
• Low current (20mA)
• Excess of 150lm/W

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From Dutta 2009

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White Light for from LEDs

The blue peak

• f

the spectrum can be used for free space optical communication, making the white LED serve dual purposes, illumination and communication.

Color Spectrum of a phosphor converted White LED

Figure : Technical Datasheet DS45, Luxeon

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No. Description Enviro Direction Data Flow Data Rate b/s Distance Intensity Channel Beam Pointing Topology Control 1 Mobile to mobile In/Out bi ~100 M 1m to 10m Single LED LOS Manual pt-to-pt Dist 2 Information Broadcast In/Out uni Asym 10M—1G 3m to 10m Strong Primarily LOS Manual/ Auto pt-to-pt Dist 3 RF Prohibited In/Out DL strong UL weak pt-multipt 4 Point to Multipoint In 5 Mobile to Fixed In bi Sym 10M--100M 1m LOS Manual pt-to-pt Dist 6 Mobile to Infrastructure In bi/uni Asym UL: 10M DL: 10M– 100M 3m to 10m LOS Manual pt-to-pt Dist 7 Fixed to Infrastructure bi/uni 10M 3m LOS Automatic WLAN Dist 8 Vehicle to Infrastructure Out bi Asym 100k 100m? Strong LOS Wide Automatic WPAN Centr 9 Vehicle to Vehicle Out bi Sym 100k 100m? Strong LOS Wide Automatic WPAN Dist 10 Mobile Display In bi Asym 100M weak LOS pt-to-pt 11 Sign ITS Out bi Asym 10M Sign: strong Mobile: weak LOS Sign: wide Mobile: narrow Manual pt-to-pt Dist 12 Illumination In bi Asym 10M 10m Lighting: Strong Mobile: weak LOS/ NLOS Light: Wide Moible: narrow Centr 13 Navigation In/Out bi/uni Uni: 10k Bi: DL: 10k—10M UL: 10M --100M pt-to-pt 14 Short Range High Speed In bi Sym 10M 3m Weak LOS Wide Manual pt-to-pt Dist 15 Long Range Low Speed Out bi Sym 1M 100m Strong LOS Wide Automatic WPAN ? 16 Aircraft Intra-Cabin Communications In bi Sym 100m Strong LOS Wide pt-to-pt Centr 17 Underwater Communications Out 18 Image Sensor with LED Tags In/Out uni 19 CE Device Control In bi/uni 10k 5m LOS Manual pt-to-pt Centr 20 E-content vending In bi Asym UL: 10k DL: 1G 0.5m Manual pt-to-pt Centr 21 E-commerce In bi Sym 10k 1m Manual pt-to-pt Centr

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Summary of 802.15 WPAN TG 7 Use Cases 802.15 TG7 VLC Participants

• Boeing
• Intel
• Samsung Electronics (Korea, San Jose, Texas)
• Nakagawa Laboratories Inc. (Japan)
• ETRI (Korea)
• Siemens AG
• Bosch (CA)
• DTC (UK)

VLCC members vlcc.net

• Sony
• Mitsubushi
• NEC
• NTT DoCoMo
• Toshiba

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Existing VLC Performance

2002 2004 2005 2007 2008 Assumptions Hong Kong 128kbps 20m Traffic light with 441 LEDs, indoor lab experiment, audio application NTT 100kbps 0.4m Desk lamp with 200 LEDs, solar board as receivers at desk level Keio 4.8kbps 2m From ceiling lamp to cell in hand, low rate based on Visible-Light Tag, location related application Nagoya 2.78k bps 4m Traffic light with 192 LEDs, indoor lab experiment, high speed camera as receiver Siemens 100Mbps 1.65m From ceiling lamp to desktop level, simulation results Samsung 100Mbps 1m Mobile to mobile, narrow FOV, lack

• f

more information Oxford 32 Mbps 2.15m 60*60 LEDs, from ceiling lamp to desk level, wide FOV Oxford 40 Mbps 2m 4*4 LEDs, 45 degree wide angle, coverage radius 0.5m

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VLC: what it isn’t

What it isn’t

IR communication (it could be, but IR is additive) Laser-based communication (e.g., rooftop FSO networks) Fiber optic communications

Considerations

Can be done with conventional lights, but LEDs are better – more controllable – smart lighting!

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Building A Building B Rooftop FSO

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Polarization

Beam forming, MIMO, safety, range

Emission Pattern

Beam width, diffusion properties, range

Internal Efficiency

Energy consumption, noise equivalent power

Modulation Speed

Luminosity/duty cycle, bandwidth, throughput

External Efficiency

Efficiency, SNR, SINR, range, modulation, safety

Spectral Control

Multichannel design, bandwidth, CDMA schemes

LED

Replication

Arrays, directionality spatial reuse

VLC and the LED Reference Model

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