As our buildings will change when our mobile devices can receive huge amounts of data from the light fixtures above our heads? The LED not only brought us a highly efficient light source, but it is also a promising instrument for visible light communications (VLC). The light will not only be a means to support the vision, but is also an essential means of data communication. With the low power consumption of an LED, we can even set up fixtures without power cables and just install Ethernet cables. Welcome to the world of digital lighting!
Outdated incandescent light sources require high energy consumption, with cables to achieve a sufficient light output. However, modern LED fixtures require much less energy. So the engineers could apply alternative techniques to feed the lighting. “Power over Ethernet” (PoE) is a technology in which electric power is provided via Ethernet, which networks you use and connect to a router with a single click. Originally designed to carry data, these cables may contain a power LED lamp current, and may combine communication with the lighting. Ethernet cables for this application are inexpensive and easy to install and, consequently, help to save on installation. When connected to other interfaces such as sensors and weather systems and security, the network may aggregate data in real time to control the building of a more dynamic. “The Edge”, an office building with sustainable design in Amsterdam, designed by PLP Architecture, is a building where this technology has been used in thousands of lamps throughout your architecture. But PoE cabling is only part of the movement of digital lighting. Communication with visible light leads to another fascinating innovation.
Harald Haas, professor of mobile communication at the University of Edinburgh, is a pioneer in visible light communication. In a demonstration in 2011 at TED in Edinburgh, Haas presented the Li-Fi, or Light Fidelity, for the first time. Li-Fi is a wireless optical communication category, using the same spectrum used for architectural lighting. How LEDs are semiconductor devices, current and optical output can be adjusted according to extremely high speeds, which is imperceptible to our eyes. Some tests have shown that the Li-Fi can be 100 times faster than Wi-Fi. In your TED Talk in 2015, Haas connected to Li-Fi technology to solar cells as a receiver, allowing additional energy storage to receive data. The integration of solar cells to the devices to the Internet of Things is an important contribution to enable the wireless battery charging. Even if the light is low, or if the weather is cloudy, the data still flow without obstruction.
One can imagine all kinds of architectural applications, ranging from bus shelters and railway stations for the lighting of streets, where people seek information on their mobile devices-transport, tourist information updates or just entertainment. Commercially, the companies could use visible light communication to offer special discounts on retail, in connection with the positioning systems (GPS) and LED individual points. The first applications, as in “The Edge” in Amsterdam, demonstrate how the system interacts with applications on mobile devices of officials to change the lighting, change the temperature and to monitor the individual energy consumption. Due to the fact that the Li-Fi does not create electromagnetic interference, this technology has important benefits for sensitive areas such as health, with medical instruments. This individual control with sensors in real time opens the possibility to minimize energy consumption, compared with General lighting solutions, when the most demanding task leads to high levels of lighting for larger areas.
Even though experts see huge potential for the PoE and the Li-Fi, there are still some issues that need to be considered. These aspects range from technology, cost, privacy and security. With little daylight, the sensors will not be able to receive data from modulated light (although a reasonable level of ambient light wouldn’t cause problems). Another limitation is the direct line of sight for data communication. In contrast to Wi-Fi, the modulated light can’t go through walls. Although this is a good point in regards to security, would require a light source Li-Fi in each different environment to hold the data. The light visible communication will therefore create smart ceilings, where light flows up, preferably for applications with large areas and long hours of operations such as commercial or office spaces-because if you turn off the lights, the LCV would stop immediately. In addition, with the Li-Fi you only receive data without a request option. This means that the smartphone would not send feedback directly to the own LEDlamp, but would use Wi-Fi to respond to the lighting network. However, a benefit for the Li-Fi will be a debate on health called “electrosmog”: the Li-Fi does not produce electrosmog in comparison with systems based on radio frequency as Wi-Fi. A notable benefit of PoE can be lighting systems can be renewed without rewiring. Data cables would be flexible enough to update or even change the protocols of communication and thus contribute to reducing the costs of renovation. Without doubt, these new systems will require an additional investment at the moment.
With the new option of receiving data via mobile devices of users, there is the important issue of privacy. What kind of data will be collected and who will be the owner of the data? Will the owner of the building will maintain control of the information, or is a supplier of lighting system?
Even though the Li-Fi is more secure than WiFi, PoE lighting definitely connect with other data streams in the building. This type of network has already aroused the interest of hackers, for example, converted a building at MIT in a game of Tetris giant through the lamps behind the Windows.
It is obvious that the connected lighting offers numerous benefits and the challenge will be to adjust the level of connectivity in a smart way. We need to get used to the idea that algorithms will determine our life and our lighting. As architects, it is our task to find the right path between dominate space and expose the automatic scenarios for comfort and energy saving.
Light matters, a monthly column about lighting, is written by Thomas Schielke. Thomas is fascinated by architectural lighting and works for DIALillumination. He has published numerous articles and is co-author of the books ‘ Light Perspectives “and” SuperLux “. For more information, see www.arclighting.de or follow him at @arcspaces.