Over the past year, EM’s editors have noticed a shift of emphasis in the lighting market by companies marketing LED lighting’s savings in energy and maintenance costs to marketing its promise as the backbone for the Internet of Things (IoT). Connected lighting systems may well be key in making the IoT reach its full potential, but its success in the LED lighting market will depend on the interoperability of the systems and the devices they connect.
A new study by the U.S. Department of Energy (DOE) looks at connected lighting systems and what it takes to get different systems to work together. First in a series of studies that DOE plans to do on connected lighting system (CLS) interoperability, the preliminary study, entitled “Connected Lighting System Interoperability Study Part 1: Application Programming Interfaces,” was prepared by researchers at Pacific Northwest National Laboratory (PNNL) and focuses on application programming interfaces (APIs) — the bits of coding that allow internet-connected devices to exchange data.
What PNNL researchers found in the study has implications for the whole universe of connected devices that make up the IoT, particularly the prospects for creating the seamless interactive network that IoT proponents tout as the key to making connected lighting systems part of a fully responsive built environment. PNNL’s conclusions point to the fact that there’s still a very long way to go.
Through a series of mock-up system tests at PNNL’s Connected Lighting Test Bed, documented extensively in the study, DOE’s researchers found that there is very little interoperability among different manufacturers’ connected lighting systems. Lighting manufacturers have to this point concentrated on developing and promoting their proprietary technologies. While more of them offer a software API, this adds complexity and expense to the integration process because it takes time and experimentation to make things work as desired.
“Integrating multiple CLS through APIs does not result in a homogenous system. At best it yields a common user interface and experience,” the report said. “Differences among network protocols, device representations, and access policies that affect performance must be understood, addressed (if possible), and managed — not only initially, but over the course of hardware, firmware, and software upgrades. Asynchronous data flow can lead to latency issues and bandwidth bottlenecks. Integrated system failures and performance issues can be very difficult to debug and subsequently isolate and mitigate, without taking down the entire system.
“Implementing mechanisms and policies that maximize reliability and quality of service while still allowing the integrated system to scale and simultaneously continue to deliver end-use functionality requires advanced developer skills,” the DOE report continued. “Further, at present, system integrators may have to navigate API implementations that are poorly or insufficiently documented, or have not been well-exercised, rendering them immature or, in some cases, unusable.”
The report acknowledges that connected lighting technology is still in its very early stages, and DOE sees its role as providing a feedback loop for developers to make improvements in the interoperability of lighting systems to avoid unnecessary duplicated effort and expense. DOE touches on the various efforts to provide a platform for interoperability, including the Open Connectivity Foundation, the TALQ Consortium, oneM2M, Bluetooth SIG, the Industrial Internet Consortium and the ZigBee Alliance. As with other technological advances, these various standardization efforts will eventually result in easier interoperability. But there’s lots of work ahead before the industry gets there.
“The APIs provided by current market-available CLS vendors can be utilized to facilitate enough interoperability between lighting systems to enable lighting-system owners and operators to implement some level of multi-vendor integration and some remote configuration and management services, as well as some adaptive lighting strategies. However, in many instances, API inconsistency and immaturity unnecessarily increase the effort required to implement these services and strategies, and reduce the value and performance that they deliver.”