After arriving home from a hard day at work, most people long for a little rest and relaxation. Imagine popping in a DVD and automatically having the lights in the room dim to preset levels while the motorized blinds close. As you get into bed later that evening, you turn off your lights and TVs, and lock all the doors with a simple push of a button on the control panel sitting on your nightstand. Then, when you leave for work in the morning, you kick the thermostat down a notch and arm the security system by simply locking your front door.

All of this and more can be a reality with the wireless home automation technologies that began to hit the consumer market last year. In a sense, the home of the future is actually available today. With three major alliances formed last year to promote competing wireless home automation technologies — and a growing number of prominent manufacturers (including some major electrical original equipment manufacturers) backing each — many analysts predict the home automation market will explode over the next several years.

In fact, In-Stat, a technology market research firm based in Scottsdale, Ariz., estimates that by the year 2007, the home networking market will have grown to $5.3 billion, up from $1.8 billion in 2002. “The master planned community market is expected to grow from 376,000 homes in 2004 to almost 1.4 million homes in 2009,” says InStat market analyst Joyce Putscher. “The majority of these homes will be new communities, but also include retrofits as well. These are primary opportunities for installations of home automation systems.”

Although wireless technology is not a homeowner's only option to implement home automation, it certainly allows for more flexibility as to where devices and their controls can be located. Anything in the home that can be controlled electrically is a potential candidate for connectivity on a wireless home automation network. And though most wireless technologies are designed for easy installation, as home automation technology becomes more common, homebuyers may begin to expect a fully functioning command and control network to come standard with their new homes. That means keeping up with the latest home control technologies will become increasingly important for electrical contractors wanting to provide the latest and greatest options to their clients, and the distributors that stock the equipment.

Although the basic premise is the same, wireless technologies for home automation are very different from their Wi-Fi counterparts, used to transmit audio, video, or Internet content through a home. This is primarily because home control typically requires short, individual commands be transmitted, as opposed to a sustained broadband signal. Ken Fairbanks, vice president of business development at SmartLabs, a developer of electronic home improvement and home automation solutions based in Irvine, Calif., explains. “On the multimedia side, bandwidth is king,” he says. “You've got to be able to push content, and that takes lots of bandwidth. To push lots of bandwidth, the networking technology becomes more costly. On the home control side, price is king.”

Presently, three main technologies are vying for market share in the wireless home automation space. Insteon, developed by SmartLabs, is a proprietary combination wireless/wired dual mesh technology that transmits communication signals via radio frequency (RF) transmissions through the air and over home electrical wires. Z-Wave, developed by Zensys, based in Upper Saddle River, N.J., is a proprietary wireless mesh networking technology. Based on the IEEE low-rate wireless personal area networking standard 802.15.4, ZigBee is an open standard developed by an alliance of companies called the ZigBee Alliance, headquartered in San Ramon, Calif. This 2003 IEEE standard defines how multiple 802.15.4 radios will transmit and receive signals, but it doesn't define how these devices will organize into a useful network and talk to each other. This is where the ZigBee Alliance comes in, defining the mesh networking protocol, security suite and application profiles that will allow devices from different manufacturers to communicate.

Insteon, Z-Wave, and ZigBee have backing from major manufacturers. Insteon cites about 350 partners, naming CompUSA Digital Living, Perceptive Automation, and Home Automated Living (HAL) as some of its backers. The Z-Wave Alliance includes companies such as Leviton, Intermatic, Cooper Wiring Devices, Logitech and Panasonic. The ZigBee Alliance lists Motorola, Cisco Systems, Texas Instruments, Eaton and Legrand as some of its backers.

Because ZigBee is an open protocol (built on top of a well-established IEEE protocol) — meaning anyone can use this technology without having to pay licensing fees — some analysts believe it has a major edge over the competition. However, Zensys has been shipping Z-Wave chips for about three years now — much longer than ZigBee and Insteon, whose products only just started reaching the consumer market in 2005.

“Interoperability across a very broad alliance of Z-Wave industry partners is critical,” says Steve Troyer, vice president of marketing at Zensys. “We've been at this longer in terms of shipping product in the marketplace than anybody else.”

Each of these wireless technologies are similar in that they use some form of a mesh network, meaning each device in the network can communicate with one another and retransmit a signal if it can't confirm a signal was received. However, the transmission methods for each of these technologies feature some fundamental differences.

While Insteon and Z-Wave use the 900 MHz frequency spectrum to transmit their wireless signals in the United States (Z-Wave transmits in the 800 MHz spectrum in Europe), ZigBee primarily uses the 2.4 GHz frequency spectrum, which is also used by Wi-Fi and other wireless technologies. The ZigBee standard does have a provision for 900 MHz transmission, but most ZigBee-compliant products transmit in the 2.4 GHz band. The ZigBee Alliance says this is because products that operate in the 2.4 GHz band can be used globally, whereas 900 MHz products can only be used in the United States.

Competitors claim that operating in this crowded spectrum makes ZigBee more likely to encounter noise issues. However, ZigBee Alliance chairman Bob Heile disagrees. “We've got 16 channels in the 2.4 band, and if a channel gets too noisy, the network can pick itself up and move to a clear channel,” says Heile, adding that the 900 MHz band is threatened by noise as well — from cordless phones that operate in this range.

The signal transmission method used by Insteon is simulcasting, as opposed to the routing method used by Z-Wave and ZigBee. With routing, the transmitter looks for the shortest or least noisy path to the receiver, but with simulcasting, the signal is broadcast to all receivers (or nodes) within range, then those nodes retransmit the signal to all nodes within their range until the message is received by the correct device. “If you think about each of those nodes being a member of a choir, they all sing at the same time,” Fairbanks says. “You get a very robust signal throughout the house.” He adds that simulcasting is a simpler technology for manufacturers to implement, which he says will give Insteon a cost advantage.

Competitors claim that Insteon's simulcasting has the potential of flooding the network with too many signals and consequently slowing down the response time of its devices or causing it to crash if 50 or more devices are used in a single network. Because initial Insteon products have had limited wireless capabilities, it remains to be seen if this will be the case.

Still, Insteon as well as ZigBee have addressing schemes that allow many thousands of devices to be added to a network, as opposed to Z-Wave's addressing scheme, which only allows for 256 devices. Although this is a potential drawback for Z-Wave users, George West, senior analyst at West Technology Research Solutions, a technology market research firm based in Mountain View, Calif., doesn't believe this is cause for concern in the average household. “Realistically, at my older home, I would probably top out at about 50 devices,” he says.

Z-Wave agrees that scalability should not be an issue. “Some of the other technologies out there have a lot of capability and can scale to very big node sizes, but there's a sacrifice that comes with that,” Troyer says. “In most cases it's cost, but in other areas its simplicity and ease of use.”

However, although single-family homes may not require the kind of scalability that ZigBee provides, analyst Putscher says that this scalability allows ZigBee to also market itself for commercial and industrial applications as well.

Meanwhile, Insteon claims a different marketing advantage — backward compatibility with its predecessor X10, which has been used for basic home networking for more than a decade. Analyst West notes that X10 is currently used by 7 million to 10 million consumers that Insteon could appeal to.

Though X10 backward compatibility isn't an inherent part of the Z-Wave or ZigBee wireless systems, both technologies have interfacing products available that allow interoperability. But some wonder how many of these X10 users will want to add on to their current network. “There are a whole series of products that interface ZigBee networks to X10 as well as many other lesser known networking protocols,” Heile says, but he adds that “because X10 does not work very well and is not very friendly to the less technical user, we do not expect these to be very high volume.”

ZigBee, Z-Wave, and Insteon networks all have the potential to be controlled and programmed through multiple access points, including computers, Web browsers, mobile phones, remotes, and simple wall switches. While backers of all three wireless technologies for residential applications claim to be more user friendly than the competition, ultimately, West indicates that they are all suitable for typical home automation needs.

“All these scenarios where you leave the house and hit one leaving-in-the-morning button and it turns off your coffee pot and lowers your thermostat — you can do that with any of these technologies,” West says.