Lighting and the Internet of Things

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By Robert F. Karlicek, Jr., Ph.D.
Professor of Electrical, Computer and Systems Engineering
Director, Center for Lighting Enabled Systems & Applications
Rensselaer Polytechnic Institute

The Internet of Things (IoT) is a hot topic these days, driven by the explosion of low-cost sensors, microprocessors, and wireless communications to provide new types of services for consumers and businesses. When these IoT platforms are dispersed in any environment huge amounts of data about energy use, environmental conditions, and human activity can be generated. These data are perceived to be extremely valuable and can be used to provide new functionality, ranging from simple voice activated commands such as Alexa answering a parent’s question, “Are the lights still on in Jimmy’s room?” to complex building management systems that control lighting; heating, ventilation, and air conditioning (HVAC); security; and space utilization using algorithms that process whole building occupancy, temperature, CO₂ level information and humidity data, among others. Statistically speaking, there are three times more IoT sensors than humans (see Fig. 1), and deployment of new IoT devices is projected to grow rapidly.

IoT platforms are becoming a disruptive force in the lighting industry, as lighting systems have three properties coveted by key segments of the developing IoT market: ubiquity, vantage point, and access to power.¹ In IoT speak, a light fixture could be called an enabling powered system with a view containing one or more “things” (typically sensors) that use either wired or wireless connectivity to feed data to a control system. Sensor data can be processed through cloud computing but will more likely be processed locally (in the light fixture itself, in the room, or elsewhere in the building) to reduce the time between sensing and system response (latency) and to address cybersecurity issues. The value of IoT for lighting companies comes from data generation using sensors in light fixtures, creating intelligent services that consumers and building managers find indispensable. This is increasingly attractive to lighting companies as solid state lighting (SSL), a disruptive technology in its own right, gets increasingly commoditized and lighting company investors and shareholders look for new non-lighting paths to revenue growth.²

The result of these evolving new market opportunities means IoT enabled lighting is slowly entering commodity lighting markets with product offerings from almost all of the main lighting fixture manufacturers as well as many smaller startup companies. IoT offerings in lighting are usually referred to as connected, intelligent or smart lighting systems, and most IoT enabled lighting systems contain simple, passive infrared (PIR) occupancy and daylight sensors; but in the future, they may contain more advanced integrated sensors³ (e.g., CO₂ sensors, IR imagers, radar sensors). Currently, different connected lighting product offerings are not fully “interoperable,” so products from different vendors cannot typically work together on the same IoT communications protocol even if they use an “open” (nonproprietary) communications platform. The issue of interoperability is widely recognized, and IoT industry groups are working to address it.

As IoT gradually infiltrates the lighting market (and almost all other markets), significant progress will need to be made in analyzing all of the data generated by the sensors. Analytics that digest the information to provide value-added services will increasingly depend on machine learning (ML) and artificial intelligence (AI) to maximize the benefit from IoT platforms. Though ML/AI systems themselves are a disruptive technology in general, their practical use is only just beginning to be realized. They are rapidly being developed in other markets like autonomous vehicles, healthcare analytics, and voice activated smart home technologies and will be applied to adaptive control of lighting and building management systems.

To summarize the current situation, the old curse “may you live in interesting times” certainly applies to the whole lighting industry, which is in the throes of major disruptions from three convolved technology platforms: 1) the continuing introduction of new SSL technologies, 2) the gradual introduction of fixture based IoT concepts, and soon, 3) the use of increasingly sophisticated ML/AI embedded systems for lighting (and building management) control. While it will be challenging for those in the lighting markets to navigate these coming changes, many already recognize that the long-term trends are clear:

Lighting cannot escape an IoT future

IoT based services are the province of networking, telecommunications and information technology companies that will transmit sensor data to end users who provide value-added data based services. These companies will ultimately address broad interoperability issues, networking platforms, privacy/cybersecurity, and data ownership management. Non-lighting companies have the deep pockets⁴ (see Fig. 2), are already spending significant amounts of capital on IoT and ML/AI technologies, and will be best positioned to monetize a connected future – including lighting. Broad IoT applications are being addressed by large consortia within the IoT industry, where few, if any, lighting companies are represented.

What’s lighting got to do with IoT?

It is highly probable that the answer to this question is not much, unless lighting companies can maintain control of the sensors and the socket. Of course, lighting system design will always be important, no longer so much for energy savings, but increasingly for human factors considerations and possibly Li-Fi.⁵ Energy considerations will still be important but only at the controls level, ultimately moving to automatic lighting control systems that will rely on sophisticated occupancy sensors, IoT connectivity, and ML/AI data analytics to squeeze energy savings out of responsive light utilization concepts and provide color tunable lighting designed to improve human health and wellness (in response to both occupancy sensing/tracking and daylighting).⁶

Is there a bright side to lighting and IoT?

There is still significant room for innovation and an upside in the lighting industry. It can come from embracing the IoT future, including the continued development of new lighting form factors and new optics capable of efficient dynamic color mixing and light pattern shaping (e.g., Lensvector,⁷ others). By working closely with IoT, IT, and lighting design software tool developers, the lighting community (designers and manufacturers) can help shape the future of the connected lighting industry.

Perhaps one of the best opportunities for lighting companies to benefit from an IoT future is to own the sensors and explore ways to make the light emission from the fixture an integral part of a luminaire’s sensory capabilities. Building off of daylight sensors incorporated into luminaires, there are new ways to use reflected light sensing of digitized illumination to perform highly accurate occupancy tracking and even generate pose-detection (e.g., standing, sitting, fallen) data. With improved lighting software design tools that take into account the spectral reflectance of a space’s surfaces, compensation for glare, and ocular light dose for human health and wellbeing, better lighting spectral power distributions could be calculated more accurately than using other non-light based techniques. When the lighting system can cost effectively sense its environment (ideally using privacy-preserving low-cost color and time-of-flight measurements^{8, 9, 10}), lighting becomes an integral and indispensable part of any lighting IoT solution.

Besides ubiquity, vantage point, and power, the lighting industry can generate invaluable lighting based data and information not only for lighting control systems but also for other IoT connected systems in building management, healthcare operations, communications, and even horticulture. By making lighting enabled sensing a requirement for IoT system operation, IoT solutions will need to embrace lighting system design and connectivity for maximum societal benefit. However, if the lighting industry cedes the sockets (and poles) and sensors (and data) to other enterprises outside of the lighting industry, a significant market opportunity will have been missed, and lighting will increasingly become a commodity non-smart plug-in to someone else’s IoT connected business future.

FOOTNOTES:
¹ Clear from digital ceiling concepts promoted by Cisco, for example, see https://industrial-iot.com/2017/04/smart_buildings_digital_ceiling/, Accessed 6/21/2018
² See Philip Lighting (now called Signify) in http://www.usa.lighting.philips.com/content/B2B_LI/en_US/internet-of-things.html, Accessed 6/18/2018
³ There are many now available for integration in lighting systems, for example, see https://gooee.com/products/sensors/, Accessed 6/20/2018
⁴ Market capitalizations for major internet and telecomm companies are ~100 times those of lighting companies
⁵ The IEEE 802.11 now has formed a light communications study group (see http://www.ieee802.org/11/Reports/lcsg_update.htm) looking at standards mobile wireless communications using light.
⁶ The most recent DOE funding opportunity seeks research on light utilization efficiency and lighting and health topics. See https://www.energy.gov/eere/ssl/articles/energy-department-announces-15-million-early-stage-solid-state-lighting-research, Accessed 6/1/2018
⁷ See, for example, http://lensvector.com, Accessed 6/21/2018
⁸ S. Afshari, T.-K. Woodstock, M.H.T. Imam, S. Mishra, A.C. Sanderson, and R.J. Radke, The Smart Conference Room: An Integrated System Testbed for Efficient, Occupancy-Aware Lighting Control. ACM International Conference on Embedded Systems for Energy-Efficient Built Environments (BuildSys), November 2015
⁹ L. Jia, S. Afshari, S. Mishra and R.J. Radke, Simulation for Pre-Visualizing and Tuning Lighting Controller Behavior. Energy and Buildings, Vol. 70, pp. 287-302, February 2014
¹⁰ L. Jia, S. Afshari, S. Mishra and R.J. Radke, Simulation for Pre-Visualizing and Tuning Lighting Controller Behavior. Energy and Buildings, Vol. 70, pp. 287-302, February 2014