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.