Visible Light Communications - Boston University

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Smart Lighting Annual Industry-Academia Days, February 13-15, 2012. EXPLODING INTEREST IN VISIBLE LIGHT. COMMUNICATIONS: AN APPLICATIONS ...
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EXPLODING INTEREST IN VISIBLE LIGHT COMMUNICATIONS: AN APPLICATIONS VIEWPOINT Thomas Little Boston University

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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OUTLINE: OPPORTUNITIES IN VLC What is VLC? The cup is half empty The cup is half full

Current evidence of the overflowing cup Final observations

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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WHAT IS VLC?

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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VISIBLE LIGHT COMMUNICATIONS Luminaire

Modulation and/or Dimming via toggling the lights

Light Intensity – “Baseband Modulation” (OOK, PAM, PPM)

Data!

Observer

Time Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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VISIBLE LIGHT COMMUNICATIONS Properties •Secure •Line of sight •High density •Free, unlicensed spectrum •Not affected by RF-noise •Mitigates RF health concerns

What’s it good for?

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Center-developed VLC transceiver

VLC: What’s It Good For? An enabling technology, NOT the main event Use it it in communications - Where LOS is important (good spatial reuse)  Where locality is important  As low cost – available – and opportune  For security, privacy Exploits how we can control solid state light engines Not ‘low power’ per se, but ‘free’ if used with lighting

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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TYPICAL VLC SIGNAL CHAIN: INDOOR SCENARIOS Wired Internet Typically Overhead Lighting

MCU/ Protocol Engine

“Downlink” “Uplink”

Channel

VLC Transceiver

“Free Space”

Typically a Mobile or Embedded Device

VLC Transceiver

MCU/Protocol Engine Device

Next: The Cup is Half Empty… Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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THE CUP IS HALF EMPTY

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HALF EMPTY “A solution looking for a problem” “No industry demand looking for VLC” “Many alternatives to using light to pass bits” Consumers of wireless systems busy adopting to new 802.11ac and 802.11ad standards No VLC products out there in the market/no contracts we are aware of Technology ‘on the verge’ Lighting industry does not understand data comms It will happen soon/don’t know when Hard nut – going to market Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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TO BOOT “VLC won’t work in the dark – how can I stream and watch TV in the dark?” “I can already do that with WiFi, right?” “It won’t work if it’s raining or foggy” (outdoors) “It’s not energy efficient” “It’s not built into my laptop” “I will see flicker” “IRDA never took off, why will this?”

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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THE CUP IS HALF FULL

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HALF FULL Rich ecosystem of international developers of VLC technologies

IEEE 802.15.7

VLC Ltd LiFi Consortium Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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HALF FULL

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HALF FULL

LiFi “one of 50 best inventions of 2011”

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HALF FULL

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HALF FULL

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HALF FULL Many have noted VLC will shine where other technologies cannot satisfy a need •Near field communications (including cable replacement) •When want to “Hide” communications or RF is not allowed •High density wireless – spatial reuse

•Where Line of Sight (LOS) makes a difference •Indoor GPS (indoor positioning)

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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NEAR FIELD COMMUNICATIONS Opportunity: High-speed download of HD movies

Video Kiosks NFC

Samsung Galaxy tab

NFC http://www.studiobriefing.net/2011/02/kiosks-replacing-video-stores/

Home Media Server

Download a DVD in seconds

Roku

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

Exchange a DVD between mobiles 18

“Hide” data Communication Continuous wireless telemetry of biodata from incident to hospital

Civilian

http://www.aircav.com/dodphoto/dod99/uh60-011.html

Defense

19 http://transition.fcc.gov/pshs/first-responders.html Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

RF NOT FEASIBLE Underwater Communications

Nakagawa Labs, Inc. Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

HIGH DENSITY WIRELESS • 500+ users • Severe contention for WiFi • Common scenario in classrooms, conference halls, other assembly spaces Airbus

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WHERE LINE OF SIGHT MAKES A DIFFERENCE

Vehicle-to-vehicle communications Safety critical latencies

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INDOOR GPS Lights are the basis for indoor positioning

Indoors

Iphone app

Outdoors Augmented Reality using location http://www.qrcodepress.com Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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CURRENT EVIDENCE OF THE OVERFLOWING CUP

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GROWTH IN WIRELESS Cisco’s Visual Network Index -- forecast the impact of modern apps •Annual growth in IP traffic •Gains in spectral efficiency

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

Spectral Efficiency

User Demand

User demand is increasing faster than gains in spectral efficiency!

Cisco VNI Forecast – Trends By 2015, traffic from wireless devices is expected to exceed traffic from wired devices.

Most of these devices are used for fixed position wireless!

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

Cisco VNI Forecast – Trends Mobile video is expected to account for a majority of internet traffic in the upcoming years.

Video streaming is an ideal use for asymmetric channels. These increases in network traffic require drastic changes in how we think of wireless communication.

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

VLC IS SET TO PROVIDE SCALE Dedicated Channels

Shared Channel

10 Mb/s

RF Wireless

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

10 Mb/s

10 Mb/s

E.g., Optical Wireless 30Mb/s Aggregate Bandwidth

FINAL OBSERVATIONS

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FINAL OBSERVATIONS • Unique characteristics of light provide opportunities • It’s not a race for speed (not a single dimension problem)  

Sure fast is good Cost, function & efficiency too

• Disruptive to RF-based businesses • Opportunistic – piggybacks on lighting • Part of ‘control’ infrastructure in immersive, adaptive lighting paradigm

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VLC APPLICATION OPPORTUNITIES Controllable LED Lighting

“Smart Grid Friendly Appliances” “Custom Lighting Control”

Hotels/Casinos

“Massive Energy Savings”

Office Buildings Stadiums/Arenas

“Streaming Video”

“Product Placement” “Indoor GPS”

Localization Services

“Asset Analysis”

Retailers Hospitals Warehouse

“Resource Tracking” Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

High Density Communication Conference Halls Transportation Hubs Convention Centers

“Promotions”

“Smart Network” “Advertisements” 31

ERC EFFORTS

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GOALS IN THIS CONTEXT 1. Localized, high-data-rate communications, and adapting to the limitations of the medium 2. Low cost 3. Responsive low-latency interaction 4. Part of immersive lighting infrastructure Immersive Lighting

From NXP

Personal Interaction with Lighting

Indoor Navigation Lighting as Wireless Access

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

COOPERATIVE VLC AND RF SYSTEM (ACCOMPLISHMENTS) Rahaim, Little

Analysis of the potential aggregate bandwidth in a cooperative system. Asymmetric VLC 10 shows improvement due to spatial reuse

Wifi VLC (4) Hybrid (4) Hybrid (8)

Average Delay [ms]

8

6

4

Wifi Saturates Early due to the division of bandwidth Cooperation offers full utilization of the WiFi and VLC channels

2

0 0

5

10

15

20

25

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Streaming Users Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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Cooperation also benefits from the scalability of VLC!

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“Lights off” and Uplink VLC (T1.2.1) Borogovac, Rahaim, Tuganbayeva, Little Analysis of the “lights off” problem shows that signal coverage can be achieved with very low emissions from overhead lights, even in areas of the room with signal shadowing and high ambient noise

High ambient noise regions due to proximity to windows

Daylight illuminance distribution

Low signal regions due to shadowing of overhead lights Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

Overhead lights illuminance distribution

INDOOR LOCALIZATION (T1.2.3) Prince Indoor Environment: 12 Luminaires and 169 Rx Positions Noise Contributing Luminaire

Signal of Interest Luminaire

3.5

Coarse Performance finds closest luminary to target, with errors ~ 0.3 m

z axis [meters]

3 2.5 2 1.5 1 0.5 0 4 3 Discrete Rx Locations

4 3

2 2

1 y axis [meters]

Fine Performance improves upon Coarse estimate if it can, if not the estimate of location is the Coarse estimate

1 0

0

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

x axis [meters]

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Contention with RF in V2V Communications (T1.2.3) Agarwal, Ganick, et al.

Automotive VLC transceiver

•Ganick, M. Figueroa, J. Lobo, P. Schimitsch, T. Rich, and T.D.C. Little, MobiSys 2010, demo and poster. • A. Agarwal and T.D.C. Little,. Intelligent Vehicles Symposium, 2010. • A. Agarwal and T.D.C. Little, IEEE Vehicular Networking Conference, 2009.

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

VIDEO STREAMING WITH SDR TESTBED (T1.2.1) Rahaim, Borogovac, Mirvakili, Koomson, Little

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PEOPLE QUERIED Rick Roberts, Intel Gordon Povey, D-Light (VLC, Ltd) Walter Kraus, LiFi, IBSEN Tech Sridhar Rajagopal, Samsung Electronics Shinichiro Haruyama, VLCC Dominic O’Brien, Oxford Karl Jessen, Osram Sylvania Eric Meulenkamp, Philips Research Klaus-Dieter Langer, Fraunhofer Mohsen Kavehrad, PSU Aaron Ganick, Bytelight Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

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ADDITIONAL APPLICATIONS

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INDOOR WIRELESS COMMUNICATIONS

Characteristics • High Density • Free, unlicensed spectrum • Not affected by RFnoise • Secure • We are flooded with light anyway • Mitigates RF health concerns Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

Wireless Healthcare – Asset Tracking Characteristics • Many existing RF devices • Security and privacy • Patients • Staff • High value equipment • Visually impaired (navigation)

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

RETAIL ANALYTICS Characteristics: •Rich custom lighting environment •Smartphones •Behavior tracking of individual shoppers •People—product— purchase linkage •Value to consumers and retailers Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

Use Case – Warehouse Control

Characteristics •Tracking, localization •Harsh, hot environment •Sometimes crowded RF environment •Often clear LOS •Self-provisioning

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

MORE OPPORTUNITIES Casinos: • Rich lighting environment • Ubiquitous video monitoring environment • Video signal egress problem in the presence of crowded RF

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

Cabins (aircraft, auto) •Moving ‘hotspots’ create dynamic contention problems (with other vehicles or fixed infrastructure) •Isolate with VLC hotspots

MAJOR BARRIERS IN VLC Barrier

Effort

Driving illumination grade LEDs at high speed

Sources (S1.3)

Increasing data rate with parallelism/arrays

High Data Rate (T1.2.1), Sources (S1.2.1), Sensors (S2.1)

Achieving low complexity/low cost modulation

Modulation (T1.2.2)

LOS characteristic of light/mobility

Mobility (T1.2.3)

Seamless interoperability with other networks Mobility (T1.2.3) Disruptive nature of VLC as a lighting product and a networking product

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012

Translational Efforts

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Why Relevant? What’s the Market? Three Markets Energy-efficient lighting

Market Potential 829 million installed downlights (US) [SSL Roadmap]

Wireless access and 350K femtocells (est. US), growth to 49M units networking (globally) by 2014 [Informa Telecoms&Media]. Compare to 260K macrocells today (US) 81 million installed WAPs (US) [Skyhook] Smart grid control

$11B market for sensors and devices for smart grid applications, growing to $21.8B in 2014 (US) [SBI]

Smart Lighting Annual Industry-Academia Days, February 13-15, 2012