Pow! EXPLODING INTEREST IN VISIBLE LIGHT COMMUNICATIONS: AN APPLICATIONS VIEWPOINT. Thomas Little Boston University

Transcription

1 Pow! EXPLODING INTEREST IN VISIBLE LIGHT COMMUNICATIONS: AN APPLICATIONS VIEWPOINT Thomas Little Boston University 1

2 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 2

3 WHAT IS VLC? 3

4 VISIBLE LIGHT COMMUNICATIONS Luminaire Modulation and/or Dimming via toggling the lights Data! Light Intensity Baseband Modulation (OOK, PAM, PPM) Observer Time 4

5 VISIBLE LIGHT COMMUNICATIONS Properties Secure Line of sight High density Free, unlicensed spectrum Not affected by RF-noise Mitigates RF health concerns Center-developed VLC transceiver What s it good for? 5

6 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 6

7 TYPICAL VLC SIGNAL CHAIN: INDOOR SCENARIOS Wired Internet Downlink Uplink Typically Overhead Lighting MCU/ Protocol Engine VLC Transceiver Channel Free Space Typically a Mobile or Embedded Device VLC Transceiver MCU/Protocol Engine Device Next: The Cup is Half Empty 7

8 THE CUP IS HALF EMPTY 8

9 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 ac and ad 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 9

10 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? 10

11 THE CUP IS HALF FULL 11

12 HALF FULL Rich ecosystem of international developers of VLC technologies IEEE VLC Ltd LiFi Consortium 12

13 HALF FULL 13

14 HALF FULL LiFi one of 50 best inventions of

15 HALF FULL 15

16 HALF FULL 16

17 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) 17

18 NEAR FIELD COMMUNICATIONS Opportunity: High-speed download of HD movies Video Kiosks NFC Samsung Galaxy tab NFC Home Media Server Download a DVD in seconds Roku Exchange a DVD between mobiles 18

19 Hide data Communication Continuous wireless telemetry of biodata from incident to hospital Civilian Defense 19

20 RF NOT FEASIBLE Underwater Communications Nakagawa Labs, Inc.

21 HIGH DENSITY WIRELESS 500+ users Severe contention for WiFi Common scenario in classrooms, conference halls, other assembly spaces Airbus 21

22 WHERE LINE OF SIGHT MAKES A DIFFERENCE Vehicle-to-vehicle communications Safety critical latencies 22

23 INDOOR GPS Lights are the basis for indoor positioning Indoors Iphone app Outdoors Augmented Reality using location 23

24 CURRENT EVIDENCE OF THE OVERFLOWING CUP 24

25 User Demand Spectral Efficiency GROWTH IN WIRELESS Cisco s Visual Network Index -- forecast the impact of modern apps Annual growth in IP traffic Gains in spectral efficiency User demand is increasing faster than gains in spectral efficiency!

26 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!

27 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.

28 VLC IS SET TO PROVIDE SCALE Shared Channel Dedicated Channels 10 Mb/s 10 Mb/s 10 Mb/s RF Wireless E.g., Optical Wireless 30Mb/s Aggregate Bandwidth

29 FINAL OBSERVATIONS 29

30 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 30

31 VLC APPLICATION OPPORTUNITIES Controllable LED Lighting Hotels/Casinos Office Buildings Stadiums/Arenas Smart Grid Friendly Appliances Custom Lighting Control Massive Energy Savings Product Placement Streaming Video Indoor GPS Asset Analysis Localization Services Retailers Hospitals Warehouse High Density Communication Conference Halls Transportation Hubs Convention Centers Promotions Smart Network Resource Tracking Advertisements 31

32 ERC EFFORTS 32

33 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 Lighting as Wireless Access Indoor Navigation

34 Average Delay [ms] COOPERATIVE VLC AND RF SYSTEM (ACCOMPLISHMENTS) Rahaim, Little Analysis of the potential aggregate bandwidth in a cooperative system. 10 Asymmetric VLC shows improvement due to spatial reuse 8 6 Wifi VLC (4) Hybrid (4) Hybrid (8) 4 Wifi Saturates Early due to the division of bandwidth 2 Cooperation offers full utilization of the WiFi and VLC channels Cooperation also benefits from the scalability of VLC! Streaming Users 34

35 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 Overhead lights illuminance distribution

36 z axis [meters] INDOOR LOCALIZATION (T1.2.3) Prince Indoor Environment: 12 Luminaires and 169 Rx Positions Noise Contributing Luminaire Signal of Interest Luminaire Coarse Performance finds closest luminary to target, with errors ~ 0.3 m Discrete Rx Locations y axis [meters] x axis [meters] 4 Fine Performance improves upon Coarse estimate if it can, if not the estimate of location is the Coarse estimate 36

37 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, A. Agarwal and T.D.C. Little, IEEE Vehicular Networking Conference, 2009.

38 VIDEO STREAMING WITH SDR TESTBED (T1.2.1) Rahaim, Borogovac, Mirvakili, Koomson, Little 38

39 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 39

40 ADDITIONAL APPLICATIONS 40

41 INDOOR WIRELESS COMMUNICATIONS Characteristics High Density Free, unlicensed spectrum Not affected by RFnoise Secure We are flooded with light anyway Mitigates RF health concerns

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

43 RETAIL ANALYTICS Characteristics: Rich custom lighting environment Smartphones Behavior tracking of individual shoppers People product purchase linkage Value to consumers and retailers

44 Use Case Warehouse Control Characteristics Tracking, localization Harsh, hot environment Sometimes crowded RF environment Often clear LOS Self-provisioning

45 MORE OPPORTUNITIES Casinos: Rich lighting environment Ubiquitous video monitoring environment Video signal egress problem in the presence of crowded RF Cabins (aircraft, auto) Moving hotspots create dynamic contention problems (with other vehicles or fixed infrastructure) Isolate with VLC hotspots

46 MAJOR BARRIERS IN VLC Barrier Driving illumination grade LEDs at high speed Effort Sources (S1.3) Increasing data rate with parallelism/arrays Achieving low complexity/low cost modulation LOS characteristic of light/mobility High Data Rate (T1.2.1), Sources (S1.2.1), Sensors (S2.1) Modulation (T1.2.2) 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 Translational Efforts 46

47 Why Relevant? What s the Market? Three Markets Energy-efficient lighting Market Potential 829 million installed downlights (US) [SSL Roadmap] Wireless access and networking 350K femtocells (est. US), growth to 49M units (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]