The general business press is awash with coverage on the “Internet of Things” (IoT), a broad term that describes connecting various standalone devices to a network, typically the Internet; collecting and performing analytics on the collected data; and perhaps even controlling such devices remotely. However, many of the scenarios being envisioned are consumer focused. So what does the IoT mean for buildings professionals? How will the IoT change what facility managers (fms) specify, buy, and operate?
Networks in buildings are nothing new. Offerings from building automation system (BAS) providers have been around for at least 20 years. Often these systems already connect over a secure wide area network (WAN) for remote access from a service center.
What IoT adds is the use of IPv6 at the field bus and device level. Traditionally, buildings have not used IP-based field buses and controllers, and most devices have connected to field bus controllers using simple digital and analog I/O methods.
But the premise of IoT is that IP (specifically IPv6, because this IP version is required to grant enough addresses) can be driven down to each individual device and controller on the field bus. As a result, the cost and complexity of setting up, managing, and dynamically modifying a building network (moves, adds, and changes) is significantly reduced, and the ease of adding new services to the network is dramatically increased.
A move to an all-IP building network will eventually happen. One might think of the 1980s and 1990s, with DECNET, SNA, FDDI, and the protocol soup that characterized office networking. All gone; all replaced by IP.
The same will happen to building networks. But when and how?
An IoT For Controls Professionals
The distinctive characteristics of building control networks merit a distinct segment within the broader IoT. This segment could be called a “community of devices,” in which devices work cooperatively with each other to achieve a larger goal, such as the comfort of an entire facility.
A community of devices can be IP-enabled and feature Internet connectivity, but it mostly operates as an autonomous and resilient peer-to-peer network, even when there is no Internet connectivity. The current buildings network is an example of a “pre-IP” community of devices with sensors, actuators, and various controllers working harmoniously to optimize comfort, safety, and energy efficiency.
As an example of a community in action, fms can consider a networked smoke detector and actuator that control a door lock. The smoke detector tells the network if it detects smoke, and the actuator subscribes to the smoke detector’s information. When the actuator receives data that a certain smoke detector in its vicinity has detected smoke, it could act to override security policies and unlock the door to allow people to exit the building or room.
This simple example doesn’t include any “brain in the sky,” nothing needs to go to the Internet, no controller needs to come back and say, “I detected smoke, and I now command the door actuator to open the door.” Rather, all the action takes place directly between the smoke detector and the door lock actuator.
Traditional building networking technologies have evolved to support such use cases, with control networking features such as standardized data exchange models and reliable group communication methods. But what happens when the networks transition to all IP? Are such community and control services available on “vanilla” IP technology? Unfortunately, the answer is no. IP may be inevitable, but today’s IP is not sufficient.
No Legacy Device Left Behind
The world of devices predates the IoT. Before the term IoT, people referred to machine-to-machine communication; before that, it was just old-fashioned device networking. There are hundreds of millions of devices already out in the field that need to be migrated into the IoT or IP-enabled world.
Today’s facilities use device control protocols such as LonWorks and BACnet. Standards like these are important because, compared to proprietary and single vendor approaches, standards offer multiple options for integrating, managing, and lowering the costs of automation. And as standards evolve, fms can continue taking advantage of the benefits without having to change much.
Fms should be aware that while gateways are a functional way to tie an old network to a new network, they tend to be static and complex to manage over time. It’s better to use IP to integrate disparate legacy protocols at the device level itself, instead of at the gateway level—providing the best of all legacy control protocols instead of forcing a choice between them.
IP All The Way: To The Smallest, Lowest Powered Devices
The appeal of an IP-enabled building automation network is that it is easier and less expensive to manage. But the economics of IP-enabling a $50 device, for instance, doesn’t make sense if it costs $10 to set up the IP connection. Transforming small, low-powered devices into IP-enabled devices using currently available silicon has been cost-prohibitive.
To address this, BAS vendors need to work with the next generation of specialized Systems on Chips (SOCs) to IP-enable as much of their portfolios as possible. To drive IP into low-cost devices, the SOCs need to provide a secure IP stack, software services that enable communities of devices, a range of connectivity options (wired and wireless), and enough processing on low-power consumption to run simple to moderately complex application code.
Wired And Wireless
While wired networks represent the majority of BAS networks, wireless has its place, especially for retrofits or small installations. But even within wireless, choices range from lower bandwidth, Zigbee type networks to high bandwidth WiFi.
Wired presents choices, too: twisted pair, power line communication, high bandwidth Ethernet, and Power over Ethernet. But the “either/or” discussion is counterproductive. The answer is “all.” Each choice is optimized to a particular environment, and each potentially has a place within a network.
IP Solutions With Future In Mind
In considering a broadened IP approach for their facilities, fms can talk to BAS vendors about their IP-related capabilities and goals. These discussions might center around migration and connectivity. For example, fms can ask vendors how they plan to:
- migrate from LonWorks or BACnet, or their own proprietary protocols, to the world of IPv6;
- go “IP all the way” (while that end goal might not always be achievable, since some sensors and other devices will continue to use simple digital or analog I/O, this question will shed insight into how vendors are preparing for the future);
- migrate to IP all the way while providing the peer-to-peer capabilities or control features that are essential to build communities of devices; and
- provide a range of connectivity options, while ensuring the various products work together seamlessly.
Fms need a game plan to incorporate IP into their networks as deeply and broadly as possible. A forward-looking dialogue with the various vendors that supply automation systems and devices is a good start for developing that IP architecture.
Nagaraj is senior vice president, general manager, Internet of Things, at Echelon Corp. in San Jose, CA. He has more than 20 years of high-tech product planning and strategy experience. He holds a B.S.E.E. from IIT Bombay, an M.S. in Computer Engineering from North Carolina State University, and an M.B.A. from Boston University.