Category: News

06 Jan 2016

Researchers create 3Gbps LiFi network with LED bulbs

Researchers at the Fraunhofer Henrich Hertz Institute (HHI) in Germany have successfully transmitted data at 3Gbps using conventional LED bulbs in a laboratory setting. In a real-world setting (at a trade fair), the same system was capable of 500Mbps.

The concept of visible light communications (VLC), or LiFi as it is sometimes known, has received a lot of attention in recent years, mostly due to the growing prevalence of LED lighting. Unlike incandescent and fluorescent bulbs, LEDs are solid-state electronics, meaning they can be controlled in much the same way as any other electronic component, and switched at a high speed. VLC is essentially WiFi — but using terahertz radiation (light) instead of microwaves (WiFi). Instead of oscillating a WiFi transmitter, VLC oscillates an LED bulb — and of course, on the receiving end there’s a photodetector instead of an antenna.

vlc_prototypeNow, unfortunately the Fraunhofer press release is almost completely devoid of detail, except for the 3Gbps bit — but we do have the technical specifications of Fraunhofer’s previous VLC system, which the 3Gbps system is based on. The previous VLC system was capable of transmitting up to 500Mbps over four meters (13 feet), or 120Mbps over 20 meters (67 feet). Rather than actually using a standard LED bulb, Fraunhofer’s VLC system is a black box, with an LED and photodetector on the front, and an Ethernet jack on the back to connect it to the rest of the network. In this system, the hardware only allowed for 30MHz of bandwidth to be used, limiting the total throughput.

To reach 3Gbps, the HHI researchers have found a way of squeezing 180MHz of bandwidth out of the LEDs — and instead of using just one LED, they now use three different colors. It is not clear whether this new technique has a higher or lower range than the previous, but it is likely the same. In real-world testing at a trade fair, with less-than-optimal atmospheric conditions, 3Gbps becomes 500Mbps — still pretty darn fast.

Visible light communication has a slew of advantages. In essence, LiFi can turn any LED lamp into a network connection. LiFi, by virtue of operating at such high frequencies (hundreds of terahertz), is well beyond the sticky tentacles of the wireless spectrum crunch and regulatory licensing. For the same reason, LiFi can be used in areas where there’s extensive RF noise (conventions, trade fairs), or where RF noise is generally prohibited (hospitals, airplanes). The Fraunhofer researchers even claim that VLC improves privacy, because your signal can be easily obscured from prying eyes with opaque materials — but as you can imagine, that’s also a tick in the “con” column as well.

Moving forward, we’re still waiting for the first commercial LiFi LED bulbs and LiFi-equipped laptops/smartphones to come to market. There are a few startups that are making headway, and numerous research groups, but no one seems to have a definitive roadmap for commercial products. With so many possible uses, from street lamp-to-car communications through to ultra-fast short-range communications, and the growing maturity of LED lighting, it’s really just a matter of time until LiFi becomes a reality.

06 Jan 2016

Acuity embeds indoor location technology into retail luminaires

Lighting vendor Acuity Brands said it has built GPS-like indoor mapping and positioning services into LED luminaires for the retail industry, a move that allows stores to guide and track onsite customers around the aisles and ping them with promotions, discounts, loyalty incentives and product information.

The Atlanta-based company is using visible light communication (VLC) and Bluetooth technology it acquired when it purchased patents and other intellectual property in April from ByteLight, a lighting-based indoor location specialist.


Atlanta-based Acuity said the capability supports a lighting-as-as-a-service business model, in which retailers would store LED-linked customer data in the computing cloud.
“Our LED luminaires enabled with ByteLight technology deliver a superior indoor positioning solution that allows retailers to engage digitally with their customers anywhere in the store,” said Steve Lydecker, Acuity’s senior vice president of applied integrated solutions. “This new capability gives the retailers the potential for increased revenue and shopper loyalty.”
Lighting-based indoor positioning systems could become the greatest thing in retail technology since the barcode. Such indoor location services allow retailers to keep close tabs on a customer’s shopping patterns and interests, to extend the digital shopping experience to the brick-and-mortar world, and to engage the shopper through various means.
For instance, a shopper who has written a shopping list at home on an app would upon walking into a store receive a map on his or her smartphone showing where all the products are located. Smart ceiling lights would recognize the shopper when she’s next to a specific product under a particular light and offer a discount. The same system could reward her with a free cup of coffee during their visit.
It also supports product tracking, enabling retailers to keep better track of inventory and to know when to replenish shelves.
US retailer Target is experimenting with lighting-based indoor location systems at around 100 stores, as reported by our sister publication Lux Review. It has not identified its technology supplier. It is believed to be sampling both VLC and Bluetooth. France’s Carrefour, one of the world’s largest retailers, is trialing a VLC system from Philips at a store in Lille, France.
GE has said that it is trialing lighting-based indoor location technology with two retailers in Europe and two in the US, although it has declined to identify them. One is thought to be ASDA, the UK arm of American retail giant Wal-Mart Stores.
GE has worked with ByteLight on some of its VLC trials. It is not clear how the acquisition of ByteLight intellectual property by GE smart lighting rival Acuity might affect the GE trials, or vice versa. Acuity has also been tapping VLC technology from Qualcomm.
VLC makes use of an LED’s natural flicker (imperceptible to the human eye) by embedding product information in the wavelength modulation at the root of the flicker. A smartphone’s camera picks up the modulation and sends the information to the shopper’s app.
Another smart lighting vendor, Gooee, has so far avoided VLC for its indoor positioning offering. Gooee provides a “Gooee Inside” engine for luminaire makers to embed. While VLC can provide more pinpoint accuracy than can Bluetooth beacons in identifying a product’s location, Gooee notes that a user must keep his or her phone constantly pointing up toward the ceiling lights so that the camera lens has line of sight. By comparison, smartphones have dedicated, embedded Bluetooth chips that can receive signals as long as they’re near the Bluetooth beacon but not necessarily in its sight.
Acuity said it is offering indoor positioning in luminaires and drivers including its:

  • Traditional recessed grid volumetric architectural luminaire
  • High-efficiency recessed grid open louvered solution
  • Open ceiling suspended retail aisle performance luminaire
  • ECOdrive LED drivers from eldoLED

For the indoor location services industry to take off in a big way, the smart lighting industry will have to prove that they are safe from hackers and that they protect end user privacy.

06 Jan 2016

British LED specialist teams with IBM Watson for IoT

The dance of partners getting together from the digital lighting industry and the information technology world is getting livelier all the time. The latest example: British LED specialist PhotonStar has spun its relationship with IBM into a full-fledged Internet of Things (IoT) collaboration.

PhotonStar said it demonstrated its Halcyon intelligent lighting technology working with IBM’s Watson IoT Cloud system, at IBM’s new global Watson IoT headquarters in Munich (pictured).

The Highlight Towers at Mies-van-der-Rohe-Straße 6 in Munich, Germany will serve as the global headquarters for IBM’s new Watson IoT unit, as well as the company’s first European Watson innovation super center. The center represents IBM’s largest investment in Europe in more than two decades. (Photo copyright: Rainer Viertlböck for IBM, sourced from Flickr.)
Watson is IBM’s business unit that sells cloud computing and Big Data services using the company’s Watson supercomputer. The computer is renowned for having beaten former Jeopardy! champions on the US television game show. IBM is harnessing it to the IoT — including to data-gathering networked LED lights — to help businesses decipher mountains of information from disparate sources and make quick and intelligent decisions, a process sometimes referred to as cognitive computing.
In March IBM said it would invest $3 billion in a new IoT division over the next four years.
PhotonStar’s Halcyon includes software and hardware geared around data collection, circadian rhythm support, and energy-saving applications. The Romsey, UK-based company had teamed with IBM nearly a year ago around IBM’s Bluemix cloud computing service, and has now stepped up the partnership to specifically support the IoT.
“The power of the IBM Watson IoT team and cognitive computing will better equip our business to uncover opportunity and find new avenues of growth,” said PhotonStar CEO James McKenzie. “We will also be better positioned to fulfill client requirements for innovative, end- to-end solutions for the commercial built environment as part of the IBM Partner ecosystem.”
In addition to demonstrating Halcyon at Watson IoT headquarters in Munich, PhotonStar has integrated it into IBM’s mobile and IoT lab at IBM’s Hursley laboratory in Hampshire, UK, where IBM hosts clients interested in deploying IoT and cloud computing services.
PhotonStar also joined IBM’s PartnerWorld program under which PhotonStar and IBM will jointly develop IoT products and services.
IBM Internet of Things vice president Bret Greenstein said the combination of the IoT and smart lighting “ has tremendous opportunity for innovation, especially in the area of buildings retrofit,” adding that it “offers up a whole new world of IoT use cases and possibilities.”
The PhotonStar IBM hookup comes soon after lighting giant Philips linked arms with IT stalwart Cisco to offer IoT and Power over Ethernet (PoE) services. Likewise, small LED specialists such as Carlsbad, CA-based NuLEDs have worked with Cisco to install PoE and data-centric lighting at schools and offices. Gooee, a lighting-focused IT startup, has begun licensing technology to different LED lamp and luminaire manufacturers. Many LED lamp makers have also tied their wares into Google’s Nest home automation product.
The gyration of lighting and IT companies has also featured changing partners. For instance, lighting powerhouse GE recently hired away IBM Watson vice president of solutions Jeff Gordon and named him chief digital officer of Current, GE’s data-oriented energy division that includes LED lighting.

06 Jan 2016

Plessey announces silicon-LED case study, die, and filaments

GaN-on-Si specialist retrofits its Plymouth manufacturing facility with light engines based on its LEDs while also announcing new LED die products and filaments for retro-styled SSL lamps

Plessey has announced that it has retrofitted its LED manufacturing facility in Plymouth, England using modular light engines that integrate the company’s gallium-nitride-on-silicon (GaN-on-Si) LEDs. The company also recently announced a new group of blue-pump LEDs that deliver wall plug efficiency of 60%. And Plessey is using its GaN-on-Si LEDs to deliver filament components that solid-state lighting (SSL) manufacturers can use to develop lamps with a classic look with multiple filaments.

Plessey has long been an advocate of GaN-on-Si technology as a way to lower LED component cost through the cheaper silicon substrate, relative to sapphire or silicon carbide, and the use of depreciated silicon IC fabs for the back end of the manufacturing process. The company first shipped its GaN-on-Si Magic (Manufactured on GaN-on-Si I/C) LEDs in early 2013, when output levels weren’t really capable of supporting general lighting applications, but the company more than doubled performance in 2013 and has continued to make improvements. Still, neither Plessey, nor any other GaN-on-Si manufacturer, has matched legacy LED performance and few such LEDs have found use in actual applications.

Clearly, Plessey is intent on showing the SSL community that its LEDs are ready for general lighting applications. The company developed its own modular light engines that it is using to retrofit a variety of linear- and compact-fluorescent lighting fixtures in its manufacturing facility. “With recent process enhancements, our LED modules create efficiencies well above existing lighting technologies,” said Mike Snaith, operation director at Plessey. “We have not only developed an efficient fixture, but have developed cost-effective ways to implement the retrofits, which is key in the return-on-investment calculation. Generally, all lamps on site are replaced annually. Fluorescent lamps, due to their mercury content, cannot just be thrown in the bin and have to be processed by a special waste facility. Therefore, they also present a toxic hazard when carrying out maintenance should a lamp break.”
The company is in the process of replacing 4200 fluorescent lamps that consume 1,000,000 kWh of electricity annually. The company said it took 200 man hours per year to maintain the legacy lighting. The retrofit is projected to save 25% to 40% on energy consumption in addition to maintenance savings.
It’s not clear whether Plessey will sell the modules commercially, although many LED makers are in the module business these days. A comment from a company executive would indicate that possibility. “The LED retrofit kits offer the facilities engineers and installation contractors a cost-effective, quick, and easy method to take advantage of the new technology,” said Thomas Abbott, Plessey’s senior facilities engineer. “Another benefit is the dramatically reduced power consumption. It only takes between 5-10 minutes to retrofit a fixture, and as a result, the emergency light fixtures now require less or smaller battery backup, meaning increased cost savings as well as reduced frequency for maintenance.”
LED emitters
At the component level, Plessey announced its second generation of blue LEDs intended for white-light applications with the addition of phosphor. The company first launched blue-pump LEDs in mid-2013 with components that could be driven at 1A. The new family includes products rated for as much as 3A of drive current.
“We have developed a wide range of LED die for a number of applications and our GaN-on-silicon technology works particularly well in higher-power applications such as high bay, street lights, projector lamps, spot lamps, and floodlighting,” said Keith Strickland, Plessey CTO. “This current process technology will become the base for our application-specific LEDs, the ASLED, which bridges the gap between LED component suppliers, solid state lighting fixture designers, and the OEMs.”
Décor lamps
The other recent Plessey announcement centered on 1×48-mm filaments that consist of a string of LEDs connected in series. The filaments are intended for use in the increasingly popular lamps that include a number of filaments that mimic incandescent lamps styled like antique lamps or what Plessey calls Décor lamps. The filaments deliver 50 lm from 18 mA and have a forward voltage of 76V.
“We have taken our existing chip-scale-packaging technology, also used for our dotLEDs, into a revised format for the filament,” said Strickland. “Not only do we have an improvement in terms of manufacturability with GaN-on-silicon and enhanced the power control for filament resistors, but Plessey will also be incorporating other active and passive electronic components for chip-on-board and chip-scale-packaging solutions in the next generation of filaments.”
The company said it will ship samples of the filaments in September. Production volumes are due in October.