"Meet George Jetson. His boy Elroy. Daughter Judy. Jane, his wife." The theme song from the 1960s cartoon classic The Jetsons brings back memories, not only of the show itself, but also of that really "way out," futuristic house they lived in. Well, the smart home isn't so "way out" anymore.
We're still a long way from wisecracking robots, automatic dining-room-table setup and cleanup, total voice command and control, and the many other "smart" aspects of that home. Yet the dovetailing of low-cost sensors, abundant computing power, ubiquitous networking and communications, and other cutting-edge technologies is putting us on the path.
Sci-fi movies have idealized aspects of the automated or smart home, like natural speech recognition and synthesis, personal identification in the form of image recognition, automatic control of the lighting and heating, and intelligent message handling and entertainment. Again, thanks to today's technologies—whether it's broadband connections to the home, multiple types of local-area networks within the home, low-cost image sensors and image processors, or control nodes that can be placed anywhere—these capabilities can no longer be considered just science fiction. And to analyze and interpret the sensor and control inputs, huge amounts of low-cost compute and signal-processing power will be needed.
At the heart of this future home resides some form of a central or distributed computing nexus, perhaps a server. It provides data access and streaming-media distribution; collects and correlates sensor data; and acts as a gateway for Internet access, handles e-mail, and many other functions. By 2006, such a system will probably run on a 5-GHz dual-processor CPU that delivers over 1000 MIPS, 1 Gbyte of RAM, and close to a terabyte (Tbyte) of hard-disk storage.
Speaking of 1960s media icons, who can forget the movie 2001: A Space Odyssey? Discussions about the application of artificial intelligence to control environments always conjure images of the movie's star, HAL the insane computer. Though we're many decades from that level of sophistication, software-driven neural networks can accomplish rudimentary levels of decision making.
To that end, part of a server's abundant computational power will be used to implement some type of neural network, which in turn would create a coordinating intelligence. For command inputs and response outputs, a good percentage of the remaining MIPS will go toward speech recognition and synthesis. Though we won't have full continuous speaker-independent speech recognition by 2006, it will be possible to offer various command and control functions well beyond a few isolated words.
Smart appliances, a staple in the Jetsons' house, are now popping up in our everyday lives for real, with infrared-controlled water faucets, motorized paper-towel dispensers with infrared hand sensors, motion-activated light controls, and even Internet-enabled microwave ovens, dishwashers, and refrigerators. Most of these devices are standalone for now. But as they become networked, things like water, paper, and electricity usage will be trackable. Supplies like paper and food can then be inventoried automatically.
By packing a huge amount of horsepower into a small piece of silicon, smart-control nodes can embed control and communications capabilities into light switches, appliances, and even plumbing fixtures. While it's a few years old, the Neuron chip from Echelon Corp. is a good example of one solution that addresses distributed sensing and control. It typically contains a microcontroller, a communications interface with Echelon's communications protocol, logic to handle the I/O and control functions, and RAM and ROM (or flash memory) to hold the commands and data. Every Neuron chip features a 48-bit address called the Neuron ID, which allows the creation of large chip networks, with each chip individually addressable. As a result, each smart-control node would combine a Neuron chip, sensors, and/or power control circuits (Fig. 1).
Low-cost sensors continue to make greater inroads into homes, with uses ranging from simple infrared emitter/detector pairs for automatic hand-towel dispensers and faucet on/off control to smart-card-like radio-frequency tags that identify objects (or people) as they move. Personalized RF tags adjust lighting, audio, temperature, etc., as you go through your home. Large, wall-mounted LCDs tied to the home system via wired or wireless networks can display art, scenery, or photos, changing to suit your profile as you enter a room with your ID tag.
Communications plays a vital role in linking sensors, audio/video, computers, appliances, and other systems together. Today's megabit/second high-speed broadband Internet access from the home to the rest of the world is just the start. It gives us limited streaming-media capability for entertainment, but adequate bandwidth for most other needs—control, e-mail, voice communications, and more. In the future, watch for 10- to 100-Mbit/s bandwidths to become commonplace as optical networks reach closer to the home and higher-speed technologies improve last-mile data rates. With such bandwidth available, remote monitoring of the home via Internet-capable cameras and control using a browser interface will become simple.
A montage of different standards dictates local communications within the home: dedicated infrared for most A/V controls; point-to-point RF for some PC peripherals (keyboards, mice, etc.); and wireless networks, wired networks, and networking over powerlines that make up most of the remaining network schemes. But little internetworking exists between these networks, leading to small "islands" of communication. In the future, there may still be different subnetworks within the home. They will be unified, though, communicating through various gateways to a central coordinating computer.
Super remote controls can now replace the half-dozen or so controls typically found in the A/V center. In fact, a new class of network-capable multifunction devices can control networked PCs to stream media from hard drives to the audio center as well as various appliances—even lawn sprinklers! Based on an embedded PC, Philips' iPronto remote control includes a wireless network interface, a touchscreen control pad that can bring up multiple contexts, an Internet browser to navigate the control and media transfer options, and other features (Fig. 2).
Over the next few years, look for ultra-wideband (UWB), ZigBee, and Bluetooth technologies (www.bluetooth.org) to squelch many of the negative issues associated with the popular 802.11a, b, and g wireless network standards (interference, distance, quality of service, etc.). UWB (IEEE 802.15.3) shows great promise as a high-bandwidth interconnect. Currently, it allows over a 10-m span of 114 Mbits/s. In 2005, that will jump to 230 Mbits/s (over 400 Mbits/s if the distance is reduced to 5 m), and by 2006, expect 1 Gbit/s over a 5-m span. This would eradicate the otherwise complex wiring involved with the distribution of high-definition video and high-quality audio (www.uwb.org). (For more about these wireless schemes, go to www.palowireless.com.)
Wireless control and sensor connections will celebrate the arrival of ZigBee (IEEE 802.15.4), the wireless standard that focuses on low-rate personal-area networking. It should find many applications in homes as a sensor and control network. ZigBee in the U.S. translates into wireless links operating at either 2.4 GHz or 915 MHz (2.4 GHz and 868 MHz in Europe), so designers can select the best frequency to optimize propagation, path loss, and data rates. ZigBee transceivers can provide a range of 10 to 100 m for a single hop, based on the environment, antenna, and frequency band. Circuits designed for ZigBee will possess very low power drains, because active transmission time is less than one-tenth of 1%. In some applications, a wireless sensor with an AAA battery can run until the battery fails for reasons other than running out of energy.
Used worldwide, the 2.4-GHz band offers 16 channels and a maximum over-the-air data rate of 250 kbits/s via a direct-sequence spread-spectrum coding scheme. The 902- to 928-MHz band serves the Americas and much of the Pacific Rim, providing 10 channels and a burst data rate of 40 kbits/s. European systems will use one channel in the 868- to 870-MHz band, which brings a 20-kbit/s burst data rate. Mid-2005 to late 2005 is the target for first silicon and systems based on the soon-to-be-ratified standard. Lighting control will be one of the first applications.
When RF solutions can't work in the application, wired solutions may be the answer. But rather than drag wiring though the house, existing home power wiring could do the trick. What's the most popular control scheme right now? If you put an X next to X.10 technology, you're right. Mostly a low-data-rate system for control (www.x10.com), it doesn't permit file transfers over powerlines.
Many of the kinks with powerline-based networking have been hammered out—slow data rates, inability to connect through some wiring junctions, and interference from some high-energy appliances—making the approach more attractive than ever. The HomePlug Powerline Alliance (www.homeplug.com) unites many vendors crafting chips and systems for powerline control and data networking.
Chip sets that transfer data at rates of 10 Mbits/s can be had now. In the near future, the rate should climb to nearly 50 Mbits/s—enough to handle one or two standard-definition video streams. Data rates are soaring past the megabit/s rates practical a few years ago. By 2006, powerline-based systems will offer data rates of 10- to 100-Mbit/s systems, enabling the distribution of audio, some video, and plenty of control information.