Smart Grid and Local Networking
The Smart Grid Meets the Digital Home
As the Smart Grid is built out with its security and intelligent networking, opportunities arise both in commercial and industrial facilities and now in the home for leveraging local networking to better manage energy as well as services for connected devices.
TOM WILLIAMS, EDITOR-IN-CHIEF
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The proliferation of wireless networks in homes, offices and commercial buildings may at first appear to be about more easily setting up computer networks that can link together in a local network that is then also connected to the Internet. The potential, however, is much more vast. We have seen wired and wireless networks at work in commercial buildings for managing energy efficiency and HVAC systems, lighting and security. Wireless sensor networks are in use in many fields from agriculture and environmental monitoring to industrial applications of many sorts. Now a huge market potential appears ready to open up for homes that will connect with the coming Smart Grid in what is becoming known as the “Internet of Things.”
The Internet of things is simply the connection of everyday objects that are networked for monitoring, control and interaction. The existence of very low-cost microcontrollers and a whole world connected via IP networks makes the connection of anything electrical—from sprinkler system controls to children’s toys—fairly straightforward. The kinds of connections that will link the home with the grid via the all-pervasive Internet will be aimed at some very specific developments that are driving this connection. The first of these is the build out of the Smart Grid itself.
The Smart Grid is both an energy distribution system and an intelligent data network. Its main purpose is a more reliable and efficient distribution system and one that is much more robust and resistant to catastrophic failure than the 70-year-old system that is now in place. One of the requirements for the Smart Grid to achieve its potential is for users, commercial, industrial and residential, to be able to manage their energy consumption, and this means that they must be able to interoperate with the Smart Grid. To this end, the U.S. National Institute of Standards and Technology (NIST) has worked with the Zigbee Alliance to sanction the Zigbee Smart Energy Profile 2.0 (SEP 2.0) as a standard for connecting the home area network (HAN) with the Internet and with the Smart Grid.
While based on Zigbee, SEP 2.0 is designed to be independent of any MAC/PHY so it can interact with a variety of networks including the HAN and the broadband Internet. From the home or from other locations, this protocol can be used to connect a wide variety of relatively low-speed devices over wired and wireless connections, enabling the potential expansion of access to the home to different products and services, many of which have not even been thought of yet. In the home, we see the convergence of the connection of traditional “consumer” products such as stereos, TVs, PCs and laptops with more “industrial” devices like heating systems, utility meters and other appliances along with the Internet of Things, which can include exercise machines, security cameras, lighting systems, smoke detectors and alarms and telemedicine devices. Many, but not all, of these things parallel what has become a wide practice in commercial buildings.
Tying all these seemingly disparate devices together is the venerable IP network. The ubiquity of IP networking in Wi-Fi, Ethernet, Internet and now Zigbee has made it the de facto center of connectivity between subnet domains and the connection to the wider world. It has put in place an infrastructure that can be expanded and adapted to even more application areas and domains of connectivity.
Several other factors driving the expansion of the home network and its connectivity to the wider world are the push for telemedicine to help keep down the rising costs of health care, and the sort of feedback loop that comes from an infrastructure that is coming into place. That is the fact that the mere existence of broadband connectivity into the home will motivate service providers to leverage that presence to offer more goods and services. Do you want to control your sprinkler system from a web page? Perhaps a knowledgeable service provider can analyze your situation (location, climate, etc.) and design a watering program to suit your needs, upload it and charge a small monthly fee for monitoring and maintenance. This is but one of myriad possible examples.
Given that the market and entrepreneurial spirit will come up with many ways to use such connectivity, getting a useable networking infrastructure into the home has its own set of requirements and these must start with where we are today. That is currently an audio/visual/data network that is mostly wireless and that connects entertainment systems and PCs to a central hub such as a router or set top box and then out to the Internet. In the home of the future (even if it doesn’t include a flying car), predicts Adam Lapede, senior director for Atheros, the home network will include other subnets, specifically one to manage energy and one for monitoring and control of other devices. All three will have different requirements but will be linked together by an IP network using the IPv6 protocol. All three will also present opportunities for expanded applications and business models down the road.
Since the home environment is not nearly as predictable or back-configurable as many commercial facilities, there will always be a need for a mix of wired and wireless connectivity to allow for such things as various construction materials or devices housed in metal enclosures that can block wireless signals. At the same time it is not always practical to run cables through a house—or an apartment building for that matter. Such buildings already have plenty of installed wiring in the form of their electrical lines.
To take advantage of this, the HomePlug Powerline Alliance has developed a standard for powerline communication called HomePlug Green PHY, which is also compliant with the IEEE 1901 draft standard for powerline networks. The Green PHY specification is a subset of the HomePlug audio/visual (AV) specification, which is designed for higher bandwidth needs in the home. Atheros is also now offering a Green PHY emulation platform for the development of “Internet of Things” products that will operate within the home network environment (Figure 1). There can also be things like Wi-Fi to HomePlug gateways and all these segments are united under IPv6, which will tie together subnets with different requirements and capabilities (Figure 2).
The PL-14 HPGP emulation development kit includes standards-based wired and wireless technologies to enable scalable IP infrastructures for smart grid, smart home, security, building automation, remote health and wellness monitoring, and other machine-to-machine (M2M) applications.
The Internet of Things in the home will involve different subnets with different requirements in a mixed wired/wireless environment. The HomePlug Av and HomePlug Green PHY specifications have been developed to tie together these domains via IPv6.
The first of these is the energy management subnet, which includes government-mandated higher levels of security. It is from here that the big energy consumers in the household—major appliances, electric vehicle chargers, HVAC systems, etc., can be monitored and controlled. For example, when time-of-day electricity pricing is implemented on the Smart Grid, major appliances should be able to detect when rates change and turn on to take advantage of the savings. Such appliances should also be available for both secure remote diagnostics and be able to send messages, alerts, etc., to the home owner. Here HomePlug Green PHY will be sufficient as it will in the third subnet, the monitor and control subnet.
Monitoring and control of small devices, “Things,” has a large potential in terms of the variety of devices and the combinations of applications in which they can participate. These include telemedicine devices, some of which might also or alternatively be connected to the higher bandwidth audio/visual/data subnet running the HomePlug AV. They will also include cameras for security or to identify users of other connected devices such as the garage door or the front door lock, intrusion and fire alarms, connections to sprinkler and pool systems and the list goes on.
Important for both the OEMs offering this infrastructure and its users is not so much what gets communicated from what devices. That is a matter for the appliance marketers and their ilk. What is important at this level is that it be a seamless, plug and play network environment where the user plugs in a device with the same confidence that its data will be available as there is that electricity will flow through the plug.
San Jose, CA.
HomePlug Powerline Alliance