With “collaboration” the mantra in the IoT of lighting, Bluetooth technology specialist Silvair today gave plenty of cause to recite it, announcing several partnerships across the value chain including luminaire maker Feilo Sylvania and half a dozen subsystem makers such as driver maker Fulham.
Silvair, based in Krakow and San Francisco, led the push toward last summer’s certification of the Bluetooth Mesh protocol, which extends Bluetooth’s range well beyond the 30-ft limitation for which it’s known. Enthusiasts believe that Bluetooth Mesh will usher in a wave of Internet of Things (IoT) lighting implementations that, among other things, will make it possible to control lighting levels and temperatures remotely, wirelessly, and through the Internet.
Silvair provides Bluetooth Mesh firmware — chips programmed with software.
“We are very excited by the release of the Bluetooth Mesh standard, and in particular Silvair’s lighting control stack,” said Feilo Sylvania’s global senior product line manager for smart lighting and controls Edward Lees.
The Silvair firmware marks one of many IoT offerings to have caught Feilo’s eye, which as LEDs Magazine has reported is positioning itself as a systems integrator working with many different information technology partners to tie luminaires into the Internet. The company might even be eyeing the acquisition of GE’s commercial smart lighting and energy entity, called Current, powered by GE.
Silvair CEO Rafal Han said the collaborations mark “the next big step on the way to creating a fully interoperable global ecosystem” with Bluetooth Mesh technology.
Silvair CEO Rafal Han said the collaborations mark “the next big step on the way to creating a fully interoperable global ecosystem” with Bluetooth Mesh technology.
Feilo’s new SylSmart integration program is aimed at expanding the role of smart lighting to include luminaire-embedded sensors that collect data. The data helps facility managers analyze building use and to make informed decisions on how to allocate space. It can also help automate other building systems, such as heating, ventilation, and air conditioning (HVAC). (Watch for further insights on Feilo Sylvania’s smart lighting initiatives in LEDs’ Q&A with Feilo CEO Christian Schraft and global director of strategy and new business development Bastiaan de Groot in the March issue).
Feilo works with some of its partners such as Silvair through its two new Smart Lighting Innovation Centers (SLICs).
“We will continue our collaboration, fostering and pushing the adoption of this much-needed standard [Bluetooth Mesh] with Silvair as the industry pioneers,” Lees said.
Silvair and Feilo are expected to reveal more details of their partnership at the Light+Building 2018 exhibition later this month in Frankfurt.
Meanwhile, Silvair said Fulham and five other subsystem manufacturers are working to embed Silvair Bluetooth Mesh capabilities into their products, which between them include drivers, controllers, sensors, switches, LED engines, and other components. The idea is to provide Bluetooth Mesh-based smart lighting in commercial settings.
Silvair plans to reveal more details of the partnerships at Light+Building. At the same time, it will also launch software to assist in the commissioning process of Bluetooth Mesh smart lighting. The tools will include a web portal and a mobile app.
“I am truly excited for all the changes in the industry that are about to happen because of smart lighting solutions based on Bluetooth Mesh technology,” said Silvair CEO Rafal Han. “We are looking forward to presenting a vast number of high-quality products using our lighting control firmware as well as introducing our commissioning platform. This is undoubtedly the next big step on the way to creating a fully interoperable global ecosystem.”
In addition to Hawhtorne, CA-based Fulham, the other partners are McWong International, based in Sacramento with a significant presence in China; Murata, based in Kyoto, Japan; Danlers, based in Chippenham, UK; ERP Power, based in Moorpark, CA; and DG Light, based in Turin, Italy.
Marking further collaboration, Silvair said all of the products will support energy harvesting owing to Silvair’s ongoing partnership with EnOcean, based in Oberhaching, Germany.
“Addressing the needs of modern lighting control systems was a key requirement in the development of the Bluetooth Mesh networking standard,” said Ken Kolderup, vice president of marketing at the Bluetooth Special Interest Group, which oversaw the Bluetooth Mesh ratifications. “We are delighted to see the rapid adoption of Bluetooth in the lighting industry, which will help accelerate the deployment of interoperable connected lighting systems that will serve as a platform for a variety of IoT services in the future.”
Source: LEDs Magazine
Bluetooth mesh networking technology is finally here. Was it worth waiting for? Can it really drive widespread adoption of connected solid-state lighting (SSL)? And what exactly does it mean that it has been designed for professional lighting applications? As one of the leading contributors to the development of this new wireless standard, Silvair has answers to questions you might be asking yourself today. Let's review the development of the standard and consider the impact it may have in bringing LED lighting into the Internet of Things (IoT) movement.
A PINCH OF HISTORY
For Silvair, the interest in Bluetooth all started back in 2013 when Google rolled out Android 4.3 with API level 18, introducing support for Bluetooth Low Energy (BLE). At that time, the company wasn't too familiar with Bluetooth, but already knew that IPv6 over the 802.15.4 standard (used by ZigBee, for example) was a pipe dream. Even with the 6Lo compression (6LoWPAN - Ipv6 over Low Power Wireless Personal Area Network, a lightweight protocol envisioned to bring IP networking to embedded or IoT devices), IPv6 was simply too heavy to fly, and 802.15.4 turned out to be too slow to give it a lift. Back in 2012-2013, Silvair was experimenting with something very similar to what Thread is today. But eventually we found this combination (IPv6 + 802.15.4) incapable of addressing the needs of professional wireless lighting. Hence, Silvair kept looking for a suitable radio technology.
Google's announcement of support for Bluetooth Low Energy in Android sparked hopes. BLE was already supported by iOS, so with Android on board, it seemed like a good candidate to try. But it did not fly, either. The single-hop range was very limited and the hub-and-spoke topology was far from anything usable for lighting needs; it could provide only a handful of point-to-point connections. Great for linking a heart rate monitor to a phone but certainly not to control a ceiling with 500 lights in a hotel lobby. There was hope, though.
BLE OFFERED THE PHYSICS
The underlying physics of BLE was very promising. Within a couple of months, Silvair managed to build a BLE module capable of communicating over a 500m single-hop distance. The company also discovered that with proper software engineering, it was able to run multiple Bluetooth roles (a GAP Observer and a GAP Broadcaster) at the same time (GAP stands for General Access Profile). This experiment was carried out in early 2014 and you can see it now being the fundamental requirement of the Mesh Profile specification (see the last paragraph in Section 3.3.1).
This could be described as the conception of Bluetooth mesh networking. After all, if the software part of an off-the-shelf Bluetooth SoC (system-on-chip) could be modified in a way that allowed receiving and retransmitting messages, building a mesh network on Bluetooth would be possible. It was "just" a matter of nailing down the details of this software and documenting it as an open specification, so others could do the same.
This "just" step took more than three years and resulted in the publication of three specifications, approximately 1000 pages combined. Indeed, it is a complex solution. But along the way, it turned out that a solid technology for connected lighting simply could not be outlined in a dozen pages and delivered within several months. The nature of wireless mesh networks is complex. Jet engines are complex, too. Cars are complex. So are cellular networks and many other technology wonders we're using every day. They are all successful because they are complex and solve the intricate nature of problems. This is what Bluetooth mesh is doing, too - trying to address the complex challenge of low-power communications in the resource-scarce IoT environment while ensuring wire-like performance in connected lighting networks. Many technologies have promised that, but none of them has delivered so far.
IT'S ALL ABOUT THE PACKET
Why should we trust that Bluetooth mesh will be different? As the Bluetooth mesh networking specifications are now public, we can start dissecting and discussing various building blocks of this new wireless standard. There are many novel and unique concepts in mesh, but perhaps the key asset and differentiator is the packet. It is extremely compact. This compactness contributes to the spectral efficiency (and throughput) of Bluetooth mesh networks.
Radio is a shared medium and data-packet collisions are one of the key problems to address. This is what makes scalability such an enormous challenge in connected lighting networks. The math is simple: A shorter packet means fewer collisions. But how short can it be? The answer is up to 29 bytes, as described in Section 3.4.4 of the Mesh Profile specification.
Of course, such design begins with the basics: compressed binary payload instead of a text representation. Covering a broad set of use cases (including connected lighting, building automation, and sensors), 11 bytes for the application payload seems appropriate. The standard allows 1-2 bytes for an opcode and up to 10 bytes for parameters, such as a value measured by a sensor, or a multidimensional light (light level, hue, saturation) with a transition time.
On top of that, there are two items that may be considered overhead, but it is an absolutely necessary overhead: addressing and propagation control (SRC, DST, CTL+TTL: 5 bytes in total) and security (IVI+NID, SEQ, AppMIC, and NetMIC). The IVI+NID is 1 byte. This byte helps identify a network (is this a network I know and have keys to interact with?). SEQ is 3 bytes and together with the unique concept of a slowly propagated IV Index, forms a 7-byte-long sequence number. Each packet sent on a mesh network has a unique sequence number, per given SRC address. The smart part here is that only 3 bytes are included in the air interface packet. The remaining 4 bytes are slow changing and are "known" to the network. Sequence is essential in two areas: detecting replayed packets (very trivial security attack) and also being the key ingredient of both network and application nonces - see Section 3.8.5 of the aforementioned spec.
SECURING THE SYSTEM
MICs, or Message Integrity Checks, define the level of security of the system. Bluetooth mesh has dual-layer security - it includes the network layer and the application layer. Messages may be secured with two independent keys. This is useful for relay nodes to authenticate a message on a network layer without enabling tampering with the application payload. A lightbulb that relays a message to a door lock cannot change the payload from "open" to "close," but it does check whether the packet belongs to its own network. The network layer MIC can be either 8 or 4 bytes long. In its shorter form, it is combined with the application layer MIC that can again be 8 or 4 bytes long.
The end result is an application payload that is sufficient for almost any building automation, lighting control, and sensor application, with strong security and flexible addressing. And this all comes in an extremely compact form factor. Combined with the modulation scheme offered by BLE, it is also feather light. Including all necessary radio interface fields, such as a preamble, an access address, and a CRC (cyclical redundancy check), it totals 47 octets. As a result, a single transmission on a single frequency lasts less than 400 μs. This is 10× less than it takes to transmit a comparable message using other existing wireless technologies. And when using the new 2M PHY introduced by Bluetooth 5, this advantage can potentially be doubled.
The success of any wireless system fundamentally relies on the spectral efficiency. It is similar to how the success of an airliner fundamentally rests on its fuel efficiency. In the low-power, ultrashort-message category, Bluetooth mesh delivers an order of magnitude more than other wireless solutions. As far as data transmission is concerned, it is the first wireless standard capable of meeting the enormous expectations of the IoT era.
Still, you may wonder why a technology from the IT and telecommunications field is right for lighting. When working on the architecture of the Bluetooth mesh system, the Bluetooth SIG's (Special Interest Group's) Mesh Working Group kept on diving deep into the roots of problems it was aiming to solve. In particular, the team of contributors has focused strongly on addressing the many challenges of the smart lighting environment. There are many reasons to treat lighting as the primary application for a mesh system. Most important, lights are everywhere and they are powered. So depending on how you look at it, a lighting control system may be the goal itself or may just be the initial step to develop more services that are based on a mesh-connected infrastructure.
Imagine an airport, a hospital, a company campus, or a high-rise, multi-tenant office building. Now imagine you want to roll out a service that requires a dense infrastructure of radio nodes - perhaps thousands of them. Rolling out adequate hardware would be very expensive, as each component would require a mounting point and power supply. Now suppose that each light is already mounted and powered, and is capable of supporting your wireless application. Suddenly, you realize the hardware is already there: a mesh network of thousands of low-power wireless computing nodes.
This is why the lighting category is so crucial for Bluetooth mesh technology. And to be a winning solution in that category, the new wireless standard had to be outstanding for connected lighting applications. Everything else comes afterward.
A TOUGH WORLD OF LIGHTING CONTROLS
There are many important details that contribute to why a given solution is good for lighting. Let's take a closer look at two simple examples.
First, consider eliminating the so-called popcorn effect. There are two challenges for wireless lighting control systems here:
A lot of effort has been put into ensuring that Bluetooth mesh networking can effectively address both of these challenges. First, it is primarily optimized for multicast traffic. So regardless of whether there are ten, a hundred, or a thousand lights in a ceiling, they can all be addressed with a single message that goes out. This message, in real life, may reach around 90% of lights. To ensure that all of them are eventually reached, the message is repeated a couple of times. With two messages, the probability of delivery of at least one message goes up to approximately 99%. With five messages in a row, the reliability jumps to five nines, or 99.999%.
Now, some lights will receive the first message, while some lights will receive one of the later messages. But we want all of the lights to turn on at exactly the same time, since this is how lighting controls have worked for us for decades. How does the new standard ensure that? Here comes the Delay parameter to the rescue. Let's say that five messages are spaced 20 ms apart. The first one goes out at T=0 with the Delay set to 100 ms. The second is sent at T=20 ms with the Delay set to 80 ms. The scheme repeats until the fifth message is sent at T=100 ms with the Delay set to 0. Now, regardless of which one is picked by a given light, all lights will turn on at exactly the same time. Of course, there is the overall execution delay of 100 ms, but that is below the human perception level. The speed of the underlying radio, combined with multicast transmissions and time-compensated retransmissions, guarantees that the final effect matches application requirements.
The second example is simpler but nicely illustrates the attention to details characterizing the Bluetooth mesh specifications. How does a lighting system behave when the power is cut off and restored later on? How should it behave? The answer is that it depends. Of course, it depends on the type of lights, what purpose they serve, etc. In some cases, you might not want a power cycle to turn the lights on (this is unfortunately the case with some popular home lighting systems). But in many other scenarios, this may be the desired behavior.
In Bluetooth mesh networking, there is a configuration state called OnPowerUp (Section 3.1.4 of the Mesh Model specification). It can be set to Off, Default, or Restore (to the last value before the power was cut off). It works in tandem with another configuration state, the Light Lightness Default (Section 22.214.171.124), which can be any arbitrary level, or the last non-zero value (e.g., if you dimmed the lights down to 20% and then turned them off, after a power cycle they will turn on but at 20%, not at their full brightness). Again, the attention to tiny details presented by the design team seems to be going much deeper than in the case of other wireless solutions.
SCALING IT UP
Scalability was the initial reason why Silvair turned to BLE when trying to find a foundation for a robust low-power mesh networking technology. Its wireless capabilities were simply much better than anything else available. This was primarily due to the extremely compact packet structure, which flies over the fastest low-energy radio. But, of course, every solution has certain limits. So what are the limits of Bluetooth mesh? The answer is, as always, it depends. It depends what the network is doing (how many and what types of messages it keeps sending around) and how it is set up. Bluetooth mesh has many parameters that may be fine-tuned to adjust its performance to specific requirements.
As a general rule of thumb, one can assume that at 200 devices (or fewer), there is no need to worry about any tuning at all. The likelihood that any two communications will collide is pretty low. So let them loose at will.
Above 200 devices, depending on how talkative they are, some collisions might occur. This is why Bluetooth mesh provides a number of tools that help optimize the network and let it grow significantly while maintaining an excellent packet delivery ratio. The most important ones include the following.
TTL, or Time To Live. It defines how many relay hops a message is allowed to travel. It is rarely the case for large networks that every sender has to be heard across the entire network. An occupancy sensor, for example, usually needs to report only to light fixtures in the same room. And maybe to a gateway, but not across the entire building, to locations where nobody is interested in its status. Setting the Default TTL to a low value (even to 0 in some cases) is a good way to significantly increase scalability.
Relays. They retransmit received messages, obviously multiplying traffic in a given space. Usually, the default setting for the relay function is "on" in order to make setting up small networks seamless. In large networks, it pays to carefully select how many devices are designated as relays and disable relaying where it is not needed. Ericsson Research has recently published a thorough case study (http://bit.ly/2xV2XLm) modeling an office floor with close to 900 talkative mesh devices. It is based on real data captured from a live network. It shows that for a case like an office floor, it is enough to assign about 1.5% of nodes as relays.
Subnets. Mesh networks can be significant in size, spanning entire multi-story buildings. But it is extremely rare that devices on separate floors need to communicate with each other. Except for administrative tasks like re-keying the entire network or shutting down the whole building, typically each floor is self-contained. This fact is why subnets are a great mechanism to confine network traffic. A mesh node can be a member of multiple subnets, so it is a good practice to have the base network spanning all floors and then have a subnet defined for each floor. And to configure the nodes to transmit only on subnets they belong to, not on the main network (except the administrative tasks). A single mesh network can have more than 4000 subnets. We have yet to build a structure that vast. Until then, subnets should help in scaling up any network you imagine.
IS THIS THE BEGINNING OF A NEW ERA?
According to wireless architects from Silvair, the v1.0 of Bluetooth mesh is much more capable than anybody has anticipated. It is a complete system for low-power, fully-interoperable mesh networking, with a deep and flexible application layer addressed in the Mesh Model and Mesh Device Properties specifications. By defining basic functionalities of network nodes, mesh models make devices aware of what function they perform, what other nodes they can connect with, and what actions can be performed upon them.
To enable maximum design flexibility, models include multiple properties that can be adjusted in accordance with specific applications. In addition to covering a full range of standard lighting functionalities, mesh models fully support additional functionality such as advanced lighting control strategies including occupancy sensing, daylight harvesting, or time scheduling. They also come with multiple tunable parameters and properties, effectively future-proofing buildings against increasingly stringent environmental requirements that we can expect to see as the world strives for a low carbon future.
With the Bluetooth mesh networking specifications already published, we will soon be able to see how these networks perform in practice, and whether this new wireless standard has what it takes to move connected lighting to another level. What already seems certain is that no other technology has fostered such a comprehensive approach to challenges typical for lighting applications. Time will tell whether this is enough.
Source: LEDs Magazine
Networked lighting controls are intelligent and programmable systems in which devices communicate to enact control strategies. Despite the extraordinary potential of these systems, adoption has been inhibited by difficulty in reliably projecting energy savings, unfamiliarity among specifiers and, notably, contractors, interoperability and complexity issues and cost. If some of these issues are addressed, the U.S. Department of Energy forecasts penetration of 28 percent in 2020 and 52 percent in 2025 in the commercial building installed lighting base.
Based on utility interest in increasing energy savings by using networked lighting controls, the DesignLights Consortium (DLC) launched an ambitious market transformation program focusing on a specification for networked lighting controls that utility rebates programs can use to qualify products, channel training focusing on contractors and distributors, and providing reliable data to guide energy savings estimates. These efforts are starting to germinate.
The DLC recently released Networked Lighting Controls Specification V2.0, updating its first specification from May 2016. The DLC is recertifying systems for the Qualified Products List (QPL) for Networked Lighting Controls. As of August 2017, 19 systems from 15 manufacturers were listed. U.S. and Canadian utilities use DLC QPLs to qualify lighting products for rebate programs. In 2017, utilities began to either require QPL listing for networked controls or launch new rebates specifically designed around this technology.
V1.0 of the specification included “required” and “reported” capabilities. The DLC required and verified system capabilities including networking of lighting and controls, luminaire and device addressability, continuous dimming, occupancy sensing, daylight harvesting, and high-end trim, and zoning. Additionally, the system must be commercially available and protected by a five-year warranty covering all components in the specification.
Reported capabilities include luminaire-level control (integrated or nonintegrated); time scheduling, load shedding, personal, or plug-load control; localized processing (distributed intelligence); BMS/EMS/HVAC integration; energy monitoring; device monitoring/remote diagnostics; type of user interface; and operational and standby power.
Most notably, V2.0 built upon V1.0 by differentiating interior and exterior systems and identifying specific requirements for exterior systems, as they often have different requirements. V2.0 also allows reporting more system information, such as application program interface, color tuning, start-up and configuration requirements, and security information.
“Advanced and networked lighting control systems have long been a complicated and confusing topic,” said Gabe Arnold, technical director, DLC. “There’s been little standardization, a myriad of options, constantly changing technology, and constantly changing offerings from manufacturers. With this new QPL resource, we are providing a tool to help break through some of that confusion. Whether you are looking to identify simple, room-based wireless systems to use on your retrofit project, a comprehensive system with cloud-based control for an enterprise client, or even just to find a system that can dim a certain type of load, the QPL provides a resource.”
More than 20 rebate programs have adopted the QPL. Of these, about a dozen have developed new programs to promote the technology through a rebate adder. Current rebates typically encourage networked controls to be installed along with LED lighting.
For example, the Mass Save Performance Lighting Program in Massachusetts offers a rebate of $2/watt saved for projects that use DLC-qualified luminaires and exceed energy code. If at least 80 percent of the connected lighting is controlled by a DLC-qualified networked control system, the rebate doubles. Through its Lighting Systems and Sensors prescriptive rebates program, Mass Save offers up to $95/DLC-qualified LED luminaire when combined with a DLC-qualified networked control system.
Rebate programs are expected to grow as the DLC addresses market barriers such as estimating energy savings and a lack of familiarity in the channel, and utilities find effective ways to incorporate networked controls. The DLC was building a database of manufacturer- and utility-reported energy savings for projects in more than 120 buildings and published its first report in September. This database will help utilities confidently project energy savings needed to justify rebates.
Meanwhile, the DLC is developing channel training on networked lighting controls specifically aimed at ECs and distributors. The DLC is planning pilot training with several utilities in 2018 and aims to offer an interactive online training program by late spring.
“All indicators show that what’s coming from connected networked lighting controls in the next few years will be even more disruptive than what occurred with LEDs,” Arnold said. “We encourage distributors and contractors to work with their local utility or rebate program and take advantage of these new resources and prepare for what’s coming.”
Another day, another matchup between a lighting company and an IT firm in an effort to turn lighting infrastructure into intelligent data networks. This time, LED lighting stalwart Acuity Brands has teamed with LocusLabs, an indoor mapping software specialist which has provided wayfinding programs to major airports such as Dallas/Fort Worth International.
LocusLabs is enabling its “location as a service” technology to work with Acuity's Atrius, which is Acuity's catch-all brand of an ever-widening set of smart lighting and lighting-based Internet of Things (IoT) services.
Acuity already offers indoor positioning services (IPS) through Atrius, so LocusLabs adds another arrow to the Acuity IPS quiver. LocusLabs has already installed its technology at airports including DFW as well as Houston's George Bush Intercontinental Airport and William P. Hobby Airport, helping passengers call up maps on their phones that guide them to terminals and shops. The lights are not believed to be involved in those cases.
Atlanta-based Acuity said LocusLabs' LocusMaps application “powers navigation in hundreds of millions of mobile devices used at airports, retail malls, multi-floor buildings, and campuses, making it easy to search, discover, and navigate large, complex indoor spaces.”
That is just the sort of thing that Acuity itself claims to have already provided at last count at over 50 million ft2 of retail space, to help shoppers find their way around sprawling aisles, and to engage those shoppers with information and discounts sent to their phones.
For example, Acuity is providing smart lights to US retail giant Target, which recently said it will roll out lighting-based indoor positioning systems accessible through a Target app at nearly half of its 1800 retail stores by Christmas.
The lighting industry is pushing retailers and other building operators to embed location services into lights, thus taking advantage of an existing infrastructure and eliminating the need to construct separate networks of beacons that require their own maintenance and power. That logic was compelling to San Francisco-based LocusLabs.
“Through its Atrius IoT platform offering, Acuity Brands is incorporating location-based services into the fabric of buildings, and a ubiquitous solution is exactly what is needed going forward for an optimal user experience,” said Campbell Kennedy, LocusLabs CEO and co-founder. “By using Atrius IoT services and sensory network, LocusLabs' location-as-a-service software platform can deliver the most accessible solution in the market for all building stakeholders to leverage their smart building investment."
While the lighting and IT industries are increasingly working together in the smart building market, they are also competing against each other. Not all end users who deploy indoor sensors and communications chips will chose to embed them in the lighting. LocusLabs itself, for instance, has not always worked through lighting.
And when Barclays plc outfitted its London investment banking headquarters with sensors that track room occupancy, for instance, it mounted those sensors under employees' desks, and not in the lighting.
For location services, Acuity offers at least two different technologies. It will embed Bluetooth beacons into luminaires. It can also turn on a technology called visible light communications (VLC), which encodes data in the modulating light beams of an LED light source. A smartphone can pick up that data via the phone's camera.
Alliances between lighting vendors and IT companies are now happening on a regular basis. Last week alone, smart lighting company Gooee (which is really as much of an IT firm as a lighting outfit) gave an equity share to IoT cloud software company Evrythng, and lighting giant Osram bought a minority stake in retail software firm beaconsmind.
Source: LEDs Magazine
The world's largest known deployment of lighting-based indoor positioning is finally going full speed ahead, as US retail giant Target plans to roll out a customer engagement system in nearly half of its 1800 stores by Christmas.
Using Bluetooth chips embedded in LED ceiling lights from Acuity Brands, Target will send signals to shoppers' phones. Drawing on a Target app, the phones will display an interactive map that guides individuals around the aisles, helping them find specific items and providing information about discounts.
“This promises to make it easier than ever to find what you’re looking for, so you can fill up your cart and get on your way,” Target chief information and digital officer Mike McNamara said in a video blog on Target's website. “It'll even tell you if the product's on sale, so you never have to miss out on an opportunity to save.” He likened the system to driving a car using GPS.
Target has been piloting indoor positioning (IPS) for several years, as LEDs Magazine's sister publication Lux first reported exclusively back in April 2015.
But like many early indoor positioning implementations, Target has held back from full-on deployment. As of two years ago, it was trialing the technology in about 100 stores.
At the time, it was kicking the tires on different methods, including both Bluetooth wireless radio as well as something called visible light communication (VLC), which sends signals to phones via LED-generated lightwaves, rather than via radio frequencies.
The lights will not only illuminate, but will also help guide you and deliver information to your phone at hundreds of Target stores.
In a decision that will disappoint VLC advocates and which some observers will find surprising, the retail chain said it has decided to use Bluetooth but not VLC, a Target spokesperson told LEDs. He declined to elaborate, and Acuity would not comment.
It could be that improvements related to the recent ratification of a Bluetooth mesh standard convinced Target to choose the radio method. The mesh standard prescribes a common method for allowing Bluetooth chips to hand off instructions to each other, effectively extending the range of Bluetooth far beyond the 30 ft that it typically provides.
Bluetooth's disadvantage compared to VLC is that it is not as accurate — it can pinpoint a product's location on a shelf to within 2–3m (about 6.5–10 ft) versus VLC's 30 cm, which is less than a foot.
But one of VLC's drawbacks is that it requires a user's phone to constantly point to the ceiling lighting, because lightwaves have to hit the phone's camera in order for the technology to work. In contrast, Bluetooth does not require line of sight for such Internet of Things (IoT) applications.
Another downside for VLC in indoor positioning projects is that lights have to always be on. That means VLC would often not function in a store or mall with plenty of natural light — say, one with a glass atrium and skylights — unless the lights were switched on when they don't have to be for traditional illumination purposes. That's one reason why Philips Lighting, a pioneering VLC enthusiast, is now using Bluetooth as well, and in some instances combining the two technologies.
Target is embedding Bluetooth transmitters in Acuity ceiling lights, the Target spokesperson said, noting that the system will only work with iPhones at first. Android support will follow later.
The rollout at Target could help boost the lighting-based IPS concept and encourage further takeup of the IoT scheme, which has been characterized by one-off implementations in single or small groups of stores — such as at an EDEKA Paschmann store in Dusseldorf and E.Leclerc store in Langon, France; at the Dubai-based retail chain aswaaq; a Carrefour store in Lille, France, and elsewhere.
As of last July, Acuity itself claimed to have deployed lighting-based indoor positioning in over 50 million ft2 of retail space, although it has been reticent about naming its users. Its trials are believed to include Walmart.
Acuity has been steadily building its indoor positioning arsenal. It picked up VLC technology when it acquired VLC specialist company ByteLight in 2015. ByteLight had been working with GE prior to the acquisition. Acuity also uses VLC technology from Qualcomm called Lumicast, and, as LEDs has reported, Acuity has used the former ByteLight team to help integrate VLC and Bluetooth into one system (if that combination exists in the Bluetooth-led system at Target, no one is saying).
Last spring, it launched a systems integration program inviting partners to help develop indoor positioning and other indoor IoT programs such as asset tracking. It also launched a Bluetooth system that tracks shopping carts around stores in order to provide retailers with information on floor traffic and also to keep tabs on the carts' whereabouts.
It's all part of push by lighting companies to morph more into information technology companies, and to develop offerings that collect data, which can then be monetized in many ways, such as by offering promotions and discounts to the IoT application users.
There is the question of whether shoppers even want guidance on their phones as they navigate around physical-world stores.
Another issue that has possibly held back indoor positioning schemes is that they raise security and privacy concerns. With that in mind, Philips Lighting left personalization out of a recent implementation at the four-story Media Markt computer and electronics shop in Eindhoven.
The lighting industry also faces another challenge: Even as more large end users such as Target decide to deploy, those users might buy from a more conventional IT supplier rather than from a lighting company.
For example, Barclays plc has deployed sensors to help monitor office usage at its investment banking headquarters in London, without embedding those sensors in lights.
For reasons like that, lighting company Osram now has a business selling Bluetooth chips, such as when it provided a retail chain with Bluetooth hardware to connect to non-Osram lights for a system at Guess and Marc O'Polo fashion shops in Switzerland.
Likewise, smart lighting specialist Gooee last year teamed with Israel's PointGrab Ltd. to tie that company's CogniPoint wall-mounted sensors into the Gooee cloud data analysis system.
Source: LEDs Magazine
ANN ARBOR—In an advance that could boost the efficiency of LED lighting by 50 percent and even pave the way for invisibility cloaking devices, a team of University of Michigan researchers has developed a new technique that peppers metallic nanoparticles into semiconductors.
It's the first technique that can inexpensively grow metal nanoparticles both on and below the surface of semiconductors. The process adds virtually no cost during manufacturing and its improved efficiency could allow manufacturers to use fewer semiconductors in finished products, making them less expensive.
The inside of the main concourse of the molecular beam epitaxy apparatus, which University of Michigan engineering researchers used to make the advanced nanoparticle-infused gallium nitride semiconductors. The semiconductors could boost LED efficiency by up to 50 percent, and even lead to invisibility cloaking devices. Image credit: Joseph Xu, Michigan Engineering
The metal nanoparticles can increase the efficiency of LEDs in several ways. They can act as tiny antennas that alter and redirect the electricity running through the semiconductor, turning more of it into light. They can also help reflect light out of the device, preventing it from being trapped inside and wasted.
The process can be used with the gallium nitride that's used in LED lighting and can also boost efficiency in other semiconductor products, including solar cells. It's detailed in a study published in the Journal of Applied Physics.
"This is a seamless addition to the manufacturing process, and that's what makes it so exciting," said Rachel Goldman, U-M professor of materials science and engineering, and physics. "The ability to make 3-D structures with these nanoparticles throughout is going to open a lot of possibilities."
The key innovation
The idea of adding nanoparticles to increase LED efficiency is not new. But previous efforts to incorporate them have been impractical for large-scale manufacturing. They focused on pricey metals like silver, gold and platinum. In addition, the size and spacing of the particles must be very precise; this required additional and expensive manufacturing steps. Furthermore, there was no cost-effective way to incorporate particles below the surface.
Former materials science PhD student Sunyeol Jun prepares the molecular beam epitaxy apparatus that’s used to make the nanoparticle-infused gallium nitride semiconductors. The semiconductors could boost LED efficiency by up to 50 percent, and even lead to invisibility cloaking devices. Image credit: Joseph Xu, Michigan Engineering
Goldman's team discovered a simpler way that integrates easily with the molecular beam epitaxy process used to make semiconductors. Molecular beam epitaxy sprays multiple layers of metallic elements onto a wafer. This creates exactly the right conductive properties for a given purpose.
The U-M researchers applied an ion beam between these layers—a step that pushes metal out of the semiconductor wafer and onto the surface. The metal forms nanoscale particles that serve the same purpose as the pricey gold and platinum flecks in earlier research. Their size and placement can be precisely controlled by varying the angle and intensity of the ion beam. And applying the ion beam over and over between each layer creates a semiconductor with the nanoparticles interspersed throughout.
"If you carefully tailor the size and spacing of nanoparticles and how deeply they're embedded, you can find a sweet spot that enhances light emissions," said Myungkoo Kang, a former graduate student in Goldman's lab and first author on the study. "This process gives us a much simpler and less expensive way to do that."
Researchers have known for years that metallic particles can collect on the surface of semiconductors during manufacturing. But they were always considered a nuisance, something that happened when the mix of elements was incorrect or the timing was off.
"From the very early days of semiconductor manufacturing, the goal was always to spray a smooth layer of elements onto the surface. If the elements formed particles instead, it was considered a mistake," Goldman said. "But we realized that those 'mistakes' are very similar to the particles that manufacturers have been trying so hard to incorporate into LEDs. So we figured out a way to make lemonade out of lemons."
Former materials science PhD student Sunyeol Jun prepares the molecular beam epitaxy apparatus that’s used to make the nanoparticle-infused gallium nitride semiconductors. The semiconductors could boost LED efficiency by up to 50 percent, and even lead to invisibility cloaking devices. Image credit: Joseph Xu, Michigan Engineering
Toward invisibility cloaks
Because the technique allows precise control over the nanoparticle distribution, the researchers say it may one day be useful for cloaks that render objects partially invisible by inducing a phenomenon known as "reverse refraction."
Reverse refraction bends light waves backwards in a way that doesn't occur in nature, potentially directing them around an object or away from the eye. The researchers believe that by carefully sizing and spacing an array of nanoparticles, they may be able to induce and control reverse refraction in specific wavelengths of light.
"For invisibility cloaking, we need to both transmit and manipulate light in very precise ways, and that's very difficult today," Goldman said. "We believe that this process could give us the level of control we need to make it work."
The team is now working to adapt the ion beam process to the specific materials used in LEDs—they estimate that the higher-efficiency lighting devices could be ready for market within the next five years, with invisibility cloaking and other applications coming further in the future.
The study is titled "Formation of embedded plasmonic Ga nanoparticle arrays and their influence on GaAs photoluminescence." The research was supported by the National Science Foundation through the Materials Research Science and Engineering Center at U-M.
Source: Nanoparticles could spur better LEDs, invisibility cloaks
Last week we mentioned the possibilities of wireless mesh controls integrating with LED light
fixtures. When the time comes that we are able to offer lighting options like this on a large
scale, the energy savings and environmental impact could be quite significant. Last Thursday
(August 3, 2017), an article came out that discussed a current application, in southern Holland
(yes - across the pond), at the Chemelot Industrial Park in Geleen. One top priority of the
conversion from fluorescent lighting to wireless mesh controlled LED lighting was to be able to
control the 17,000 outdoor lights to either turn on or off and/or increase or decrease the lumen
output when and where it is necessary. Now that is awesome!
The article that I am referring to is “Wireless mesh controls augur huge savings, slash light
pollution at Dutch chemical plant” Published on August 3, 2017, By Mark Halper, Contributing
Editor, LEDs Magazine, and Business/Energy/Technology Journalist. The article states:
“The new ability to turn lights off and to dim them augurs enormous savings in electricity and
CO 2 emissions. It should also drastically reduce light pollution…The combination of the LED
luminaires and the wireless mesh controls should also slash maintenance costs, given the
expected long life of the LEDs as well as the modules' ability to monitor the performance of the
“Because we 'switch' the lights with software, dimming and switching is now possible,” said Han
Bak, CEO of Haarlem-based Chess Wise, the company providing the mesh technology which it
calls MyriaMesh [Chess Wise is one of several lighting-related companies involved in a one-for-
one replacement of existing fluorescent luminaires with LED models in a 15-year service-based
scheme]. “The main thing is the lights are only on when you really need light, which is
completely the opposite of the existing situation, when the lights were on 24/7.”
“MyriaMesh uses Bluetooth radio chips, but Chess Wise deploys its own proprietary radio-
agnostic mesh protocol, rather than using the recently ratified Bluetooth mesh standard. Chess
Wise builds modules that operate at either 868 MHz or at the Bluetooth frequency of 2.4 GHz,
as it has done for Chemelot.
Bak said Chess Wise is considering a Bluetooth mesh version to support customers who might
prefer it. Different requirements would benefit from different protocols. For example,
MyriaMesh might work better when signals have to travel longer distances between luminaires.
Chemelot's 17,000 lights are an apt fit with the MyriaMesh brand name, as “myria” literally
means a unit of 10,000.”
We will keep our eyes out for more examples and do our best to keep you updated on the
progress of Bluetooth mesh and LED lighting.
Green Creative's THINFIT Series 6- and 4-in. LED downlights for new construction are Energy Star certified
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“These downlight’s quick-connect accessory makes installation fast and easy with no rewiring necessary.” says Green Creative’s Marketing Director, Matt Leonard. “As a result, these naturally low glare downlights integrate seamlessly into all ceiling applications.”
All wiring takes place inside the integrated J-box which features a pre-installed wire clamp, quick connects and an easily removable lid. The THINFIT Series slim design allows these IC-rated downlights to fit seamlessly into any type of ceiling, including those with shallow plenum space.
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Find out more here: GreenElectricalSupply.com
Source: LEDs Magazine
WEST CALDWELL, N.J. (August 19, 2016) – MaxLite has expanded its line of LED Post Top Lamps with higher output models designed to replace 125- to 175-watt metal halide sources in enclosed outdoor lighting fixtures.
Designed for use in post top luminaires with an E39 socket, such as acorn fixtures, the 30- and 50-watt retrofit lamps deliver respective outputs of 3,000 and 5,000 lumens with an omnidirectional beam that creates ample and even illumination. The new models are DesignLights Consortium (DLC) listed and eligible for utility rebate programs, making the lamps an economical choice for upgrading post top luminaires in parks, streets, campuses, airports and retail centers to more energy efficient lighting. Available in 3000K and 5000K color temperatures, the lamps save more than 70 percent in energy and operating costs over conventional light sources and feature a maintenance-free lifetime of 50,000 hours.
MaxLite LED Post Top Lamps are suitable for use in both dry and damp locations with ambient temperatures ranging from minus 20 degrees to 140 degrees Fahrenheit. The line of specialty outdoor lamps also includes 50-, 75- and 100-watt equivalents for use in lower wattage fixtures, such as bollards and globes. All lamps are backed by MaxLite’s five-year limited warranty and lifetime product support.
View complete product specifications at http://www.greenelectricalsupply.com/maxlite-30-watt-5000k-120-277v-led-corn-cob-post-top-retrofit.aspx
Hello MSSLC Members: I imagine most everyone is familiar with the recent position statement issued by the American Medical Association (AMA) on "high-intensity street lighting," due to the extensive media coverage following its release. We continue to field inquiries that include many passed along from our member municipalities and utilities, originating from their citizens and customers. The messages contained in the release have caused a stir.
DOE's Solid-State Lighting Program issued an SSL Postings within a few days of the AMA's release. This notes the importance of matching the characteristics of the product with the specific application, underscoring the AMA's call for the use of appropriate products. Since then a number of other organizations have also weighed in with very useful perspectives. You might want to check these out if you haven't already:
In addition to the above I thought I might also provide some numbers for your use should you continue to get inquiries from your respective agencies and citizens. Probably most people do not have access to the actual spectral contents of the different types of lighting in common use or know how they compare with one another, even if they understand that virtually all lighting sources produce some amount of melanopic content. Melanopic content is of interest here because it is regarded as a primary indicator of the relative potential for the listed light sources to stimulate the human biological responses that are the subject of much of the AMA's statement. Note, however, that influences from other photoreceptors like the rods and cones are also known to contribute to biological responses such as circadian and neurophysiological regulation, but in ways that are not fully clear to the medical research community.
Table 1 lists various sources used in street and area lighting and selected performance characteristics related to their spectral content. Data for each source includes a measured Correlated Color Temperature (CCT), the calculated percentage of radiant power contained in "blue wavelengths" (defined here from the literature related to sky glow as wavelengths between 405 and 530 nanometers [nm]), and the corresponding scotopic and melanopic multipliers relative to a high-pressure sodium (HPS) baseline, normalized for equivalent lumen output. Note that research on the contributions of different types of photoreceptors to visual and non-visual responses continues (e.g., see Amundadottir, 2016; Schlangen, 2016; Lucas et al., 2014) and may warrant updates to this table in the future.
Table 1. Selected blue light characteristics of various outdoor lighting sources at equivalent lumen output.
* Percent blue calculated according to LSPDD: Light Spectral Power Distribution Database, http://galileo.graphycs.cegepsherbrooke.qc.CA/app/en/home. The specific calculation, developed for evaluating the potential for affecting sky glow, divides the radiant power contained in the wavelengths between 405 and 530 nm by the total radiant power contained from 380 to 780 nm, for each light source.
** Melanopic content calculated according to CIE Irradiance Toolbox, http://files.cie.co.at/784_TN003_Toolbox.xls, 2015 as derived from Lucas et al., 2014.
Key: PC -- Phosphor Converted; LED -- Light Emitting Diode
As most products differ slightly from one another, the scotopic and melanopic values presented should be taken as being typical for the associated light source type, rather than exact. We have included ranges, for which we have data, to indicate the upper and lower limits that might be found in a representative set of LED product samples. The number of product samples underlying each CCT ranges from 2 (for 2700 K) to 19 (for 3000 K), with others falling in between (76 samples in all). Conventional light sources are all listed with single values rather than a range because DOE has performed less testing on those, but they would likewise be most accurately characterized by a range (albeit narrower than LED).
It is important to understand that performing a calculation with these values only provides an idea of the relative potential to cause human health impacts, rather than the actual (if any) impact of the melanopic content. These values do not yet take into account several critically-contributing factors noted in the LRC paper linked above, such as the intensity one might expect to find inside a bedroom from a streetlight outside. Furthermore, the melanopic content itself directly scales with light output for a given source, so reducing output by dimming dynamically reduces the corresponding content.
Finally, note that the scotopic and melanopic contents reported are listed relative to HPS, which was selected as the baseline for comparison due to its predominance in the existing outdoor lighting market.
The influence of blue wavelengths is immediately evident in all "white light" sources containing them. In addition, as demonstrated by the relative melanopic contents of conventional lighting sources in the table, the blue light issues being raised by the AMA are clearly nothing new to our lighted environment. What is new is our increased understanding of their potential influence regarding human and environmental health issues, as the related research progresses.
Estimating the potential impacts
A commonly cited advantage of LED lighting is the superior control available over its light distribution. This advantage arises because a luminaire needs to fit its output to a target area, for example a rectangular stretch of roadway extending 100+ feet out from under each side of a streetlight. To satisfy the application, fixtures employing omni-directional emitters like glass lamps require significant reshaping of the lamp's output through reflectors and lenses, and despite great skill in this regard, the results remain far from perfect with large components of the light continuing to exit the fixture in unwanted directions. The latter often results in light trespass, glare, uplight (in older installations especially) and non-uniform illumination on the ground, all of which amount to wasted light and energy. In contrast, because LEDs emit in only one hemispherical direction, the optics' job of shaping their light output into the pattern wanted is much easier from the start, and thereby enables the elimination of much of this waste.
One direct benefit resulting from the improved distribution is that lamp-based fixtures are now routinely being replaced with LED products that emit only half (or less) of the light output of the replaced conventional light source. This is a key concept for estimating the potential for impact from a lighting conversion program. For example, if product X has a melanopic content twice that of product Y, but can be run at one-third the output, then converting to product X might actually reduce melanopic output. As previously noted, dimming a given product similarly reduces its emitted melanopic content, in direct proportion to the reduced light output.
Numerous real-world examples exist of such reductions being achieved in actual street lighting conversion programs around the U.S. As a salient example, the city where I live, Portland, OR, has replaced its previous 100 W HPS fixtures emitting about 9,000 lumens (initial) with 4000 K LED products that are set to an initial output of 3,000 lumens, achieving a two-thirds reduction. As a result, in absolute terms, the LED products in Portland have likely had little impact on the melanopic output compared to the previous (and notably non-white) HPS fixtures they replaced, because the reduced light output offsets the LED's higher melanopic multiplier.
A second example is Cambridge, MA, which installed a dimming control system when it converted its street lighting to LED in 2013. According to a complete inventory of its lighting system at the time, the city replaced a total of about 54 million lumens (initial) of HPS lighting with about 32 million lumens (initial) of 4000 K LED lighting. The city's "maintained" setting of the controls system is at 70% output, meaning it actually only uses about 22.4 million lumens to light its streets at dusk when the lights first come on. Moreover, at midnight the dimmer setting is further reduced by another 50% (i.e., to 35% of full output), where it remains until early morning. Assuming even a high melanopic content factor relative to the original HPS of 3.4, during the initial evening hours its relative melanopic content emissions would amount to 3.4 x (22.4/54) = 1.41x those of the original HPS system. From midnight to the early morning hours, this value is reduced again by 0.5, yielding a factor of about 0.71x. In other words, the Cambridge system has offset the increase in melanopic content of converting to 4000 K lights, at least during the middle of the night, by reducing their output while still gaining the benefits of improved visibility, reduced energy and maintenance, and increased lifetime and reliability.
To summarize a few key takeaways:
The real value in LEDs, as has been stressed all along, comes from the combination of these elements. The wide-ranging capabilities and characteristics of LEDs are greater than any other lighting source that has come before them, and thus they offer unparalleled potential for addressing the issues raised by the AMA. As noted in the SSL Postings, LEDs are a critical part of the solution provided that these functionalities are applied. This is the message that should be shared.
I hope this information is helpful in planning and understanding the potential impacts of your own conversion efforts. I would like to extend my sincere thanks to George Brainard, Ph.D., and Robert Lucas, Ph.D., who reviewed and commented on this issue of The Light Post for accuracy. Their assistance is greatly appreciated. Bruce Kinzey, MSSLC Director Pacific Northwest National Laboratory MSSLC@pnnl.gov
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