The once-mundane streetlight could become the key to networked municipalities.
As planners envision the infrastructure of the future, street lighting is emerging as a key part of the equation, with projects in areas as far-flung as London, U.K., and Atlanta, Ga., USA. “Really, the streetlight is becoming a node in a larger smart-city network,” says Marc Dyble of Osram Optoelectronics, “that can now communicate fixture to fixture and fixture to infrastructure and even now fixture to car.” Here’s a bit about how it might work.
1. The luminaire
The streetlight part of the smart-city vision begins with the luminaire, which—as LED sources have displaced others such as high-temperature sodium lighting—has become more compact, lighter and better-performing. While energy savings have driven much of the transition to more efficient LEDs, that shift also offers new opportunities for directing light and for customized control of color temperature, brightness and appearance. Future fixtures may even incorporate pixel-level LEDs, such as those now in some automobiles, for virtually unlimited control of light distribution and patterning.
2. The light pole
The luminaire will sit atop an increasingly functional light pole, tricked out with a camera, electronic signage and a variety of image, environmental, water, seismic and sound sensors—many of them bolted onto existing, older poles as late-stage add-ons. This smart pole will allow for municipalities to monitor power consumption and status of existing fixtures, but also to count traffic, monitor local pollution, change lighting based on ambient conditions (such a fog), or detect sounds, such as gunshots, that require a law-enforcement response.
Combining LED and sensor technology, networking and intelligence could bring highly adaptive driving experiences.
3. The network
These functional light poles gain significant power when tied together in a mesh network, via Bluetooth Mesh or other protocols being marketed by a number of firms. The mesh, consisting of the overlapping signals of multiple, wireless-enabled poles that “talk” with each other, allows a view of the entire lighting system and its status as an integrated whole. This connectivity—coupled with the rich data from pole-mounted sensors—could, for example, allow local authorities, in the event of an accident or a report of a crime, to shift light levels and redirect traffic in real time. And the overlapping mesh topology means that, if a fixture in the network fails, communication can easily hop around it to find an alternative path.
4. Communicative cars
Still more integration between traffic and infrastructure will come as vehicles increasingly communicate with the smart-streetlight network via wireless technologies. Earlier this year, for example, two startup firms in St. Louis, Mo., USA, demonstrated a project in which two electric cars communicated with each other, exchanging information via the streetlight mesh. Communications between streetlights and the cellphones in people’s pockets might also allow the lighting environment to adapt to individuals walking or cycling on the street.
5. Putting it all together
The combined result of LED and sensor technology, networking and intelligence could result in highly adaptive driving experiences. Industry sources, for example, talk about scenarios in which LED streetlights, dimmed to save power, ramp up to full power as a vehicle approaches, aim and re-aim light dynamically as the vehicle passes, and then dim back down. Patterned light from streetlight-mounted pixel LEDs could provide custom scenes and directionals as your vehicle approaches a public event in the city. But watch out—a smart streetlight might also be monitoring that great parking space you snagged, to be sure you’ve moved on when your allotted time is up.