Most lighting control systems are still based on legacy connectivity models, which are proprietary to the domain. Deeper integration with Internet of Things (IoT) technologies stands out as the next major disruptive transformation leading to truly smart lighting seamlessly integrated with the infrastructure of connected managed buildings. Advanced IoT processing and connectivity enable improved sustainability and maintainability as well as enhanced, personalized user experiences in our interactions with the spaces where we live or work resulting in increased comfort and well-being.

Over the past three years, a consortium of leading European companies worked on defining and implementing a set of Open Architectures for Intelligent Solid-State Lighting (OpenAIS for short). The OpenAIS project, partly funded by the European Union within the Horizon 2020 program, has showcased how IoT technologies can be more deeply integrated and significantly transform lighting controls as part of the smart connected buildings of the near future.

The architecture deliverables of the OpenAIS project describe using digital network communication based on IP packets for lighting controls as well as for collecting integrated sensor data. This facilitates installation and maintenance associated with the lighting equipment. The same network infrastructure can be reused as a building-wide backbone for other application domains or to seamlessly integrate with generic IT and building management systems.

The OpenAIS architecture and its instantiation in a full-scale real office building pilot demonstrator also showed how open collaborative ecosystems can enable communities to deliver intelligent lighting solutions, which work well together and are easy to install, use, and maintain.

OPENAIS NETWORK ARCHITECTURE

The OpenAIS connectivity architecture is based on a common IPv6 wired and wireless mixed segment network fabric. The system technology recommendations are using Ethernet/PoE for the wired segments and Thread for the wireless segments. However, the OpenAIS network can also support any other IPv6-enabled transports.

IPv6 packets can flow end-to-end across the different segments interconnected via inexpensive, generic switching or routing equipment that does not require lighting application domain knowledge. Backbone and edge segments can be installed and managed in a unified manner leveraging IT network domain expertise or existing infrastructure. Furthermore, this generic network can be used for various other machine-to-machine signaling or data collection.

Guaranteeing multi-vendor interoperability was an essential requirement for the OpenAIS network system definition. For the wireless segments, interoperability requirements drove the recommendation of using the Thread protocol as the prominent IPv6 network technology for the IoT.

In summary, the OpenAIS architecture described a network system having the following characteristics:

• IPv6-based communication with UDP as the transport layer, supporting IPv6 multicast across both wired or wireless network segments.
• All application layer communication uses the well-standardized CoAP protocol defined by the IETF for use in the domain of constrained embedded devices.
• Security and privacy of data communication are achieved by using a combination of transport layer and application layer commissioning, provisioning and encryption.

LIGHTING DOMAIN COMMUNICATION PATTERNS

Expanding generic IP networks to adequately cover lighting controls at a large scale across multiple heterogeneous network segments presents challenges, which when addressed resulted in some of the most valuable OpenAIS architecture definitions:

• Defined as a low-latency, highly synchronous group communication pattern and protocol. This assumes a many-to-many topology using multicast IPv6 addressing. For lighting controls, group communication takes center stage and is recommended for increased scalability in high node count systems instead of the more traditional client-server or device-to-cloud unicast patterns.
• Described a decentralized controls operation model, which does not depend on a central management server for basic communication to be established and secured. The controls model can be built with redundancy and can degrade gracefully to achieve basic functionality even when connectivity to such central infrastructure is lost or not available. Such basic functionality may be simple but essential light switching, which is necessarily real-time.
• Provided a flexible application layer API, optimized for the underlying network - the OpenAIS project defined and delivered an Object Model for highly intelligent, versatile and future-proof connected lighting device functionality.

OPENAIS PILOT DEMONSTRATOR

The OpenAIS system pilot demonstrator was installed in early 2018 in the GGD offices located at the industrial heritage building De Witte Dame (The White Lady) in central Eindhoven, The Netherlands.

The demonstrator included:

• 400+ lighting nodes luminaires, connected by a digital IP network using Ethernet/PoE/UPoE for the backbone and wired segments and Thread for wireless segments
• Advanced lighting control strategies including local occupancy and light level sensing per luminaire, granular sensing and control strategies (local dimming), and personal control via a smartphone office app
• Aggregated data regarding zone occupancy was collected and made available to the facility managers so they can assess the space utilization efficiency.

For the pilot demonstrator, several OpenAIS consortium members provided Thread technology building blocks having undergone the Thread Group certification programs for the deployed components. The use of Thread as a native IPv6 protocol with each node having its own IPv6 address also allowed natural interconnection between the light points connected to the wireless network segments and the wired Ethernet-based segments via generic Thread Border Routers. Furthermore, Thread allowed the same non-differentiated application firmware modules to be reused across all wired and wireless devices.

The OpenAIS consortium and project partners were Signify (formerly Philips Lighting), Zumtobel Lighting, Tridonic, Johnson Controls, Dynniq, NXP, ARM, Eindhoven University of Technology and TNO-ESI.

A fully detailed description of the OpenAIS final architecture and pilot demonstrator validation results is available at the consortium website.

Another demonstrator of the project has been showcased at the LED professional Symposium and Expo 2018.

An overview video is available below: