Should the smart grid be built on internet protocol? Opinions vary on this, but on the technology front, we’re seeing fewer excuses that IP can’t be applied to the “smart objects” of the grid.
That’s one observation to take away from the Internet Protocol for Smart Object Alliance (IPSO) and its end-to-end IP compatibility for smart devices test in Paris earlier this month. Participants including Atmel, Ericsson, INRIA, Lulea, NXP, Sensinode, SICS, STMicroelectronics, Watteco, Wisenet, and Texas Instruments were “able to exchange messages across different media, multiple hardware platforms, and various stack implementations,” according to Wednesday’s announcement.
Notably, the tests using IETF standard protocols “showed direct device-to-device interoperability, a first for the industry.” Device-to-device interoperability is critical, because so many smart grid systems communicate via mesh networks that rely on one another to get messages from one place to the other.
Application-layer compatibility, on the other hand, will be critical if we’re to open up the world’s software talent to “apps-store” concepts, like the Green Button standard for home energy data, or the various cloud-based utility services being built by startups and giants in the grid space. “At IPSO's April event, all nine participating companies used a common application layer protocol running on actual products to deliver such interoperability across all seven layers of the OSI stack,” the announcement says.
Test participants, representing a who’s-who of smart grid circuit-makers, used both powerline communications and sub-gigahertz and 2.4-gigahertz wireless in their interoperability tests. What they didn’t do is rely completely on standard software -- while some were build on Contiki, Java and TinyOS, others were built on proprietary stacks, the alliance said.
How prepared is the smart grid industry to adopt IP en masse? Silver Spring Networks was an early champion of IP-based smart meter networking, and the rest of the smart meter giants have come on board with their own IP offerings. Almost all of these contenders use at least one technology, whether it be the physical layer (the radios), the communications protocols or the applications architecture, that are proprietary in one aspect or another, however. Cisco’s acquisition of Arch Rock, and its partnership with Itron, comes close to a platform that could lay claim to end-to-end IP capabilities, but it will still have to communicate with lots of legacy grid gear that doesn’t speak its language, so to speak.
At the same time, alternative standards like ZigBee have grown to dominate the smart meter-to-home area network plans of North America’s utilities, although ZigBee Smart Energy Profile, the dominant “standard” in that space, isn’t IP-compatible. The ZigBee Alliance is working with the Wi-Fi and HomePlug alliances on a 2.0 version that is IP-enabled, but it’s taking a long time.
In the end, of course, no single standard can dominate in the smart grid. Let’s start with the harsh reality that all of today’s installed grid gear uses legacy protocols, and much of the SCADA “smarts” in the grid today lacks the processing power and bandwidth to adopt IP. That means lots of integration work that can’t be avoided.