When Ultra-Wideband (UWB) first came to market, it didn’t have a “killer app.” Everyone knew it was a high-speed wireless data option for short range, but that was about it. Moving video around wirelessly in consumer home entertainment centers was an early target, but that never got traction.
Nowadays, though, that’s changing. Generally, you can think of UWB as a wire replacement. It all began when someone decided to make a wireless USB radio, and that has become the killer app—so far. Over the last year or so, some really interesting and innovative applications have emerged.
USB is now the unquestioned PC peripheral interface. It connects virtually all external I/O devices to the PC, from mice and keyboards to printers and external hard drives. It can be used for anything. The USB Implementer’s Forum sets, maintains, and promotes the USB standard.
Certified Wireless USB, a formal standard using the WiMedia UWB technology, is totally seamless in connectivity. A PC can add a Wireless USB host radio that talks to a wireless USB hub, with one or more remote peripherals plugged into it (Fig. 1). Network products are already available from the likes of Belkin, D-Link, and IOgear.
If only one peripheral is involved, it can talk to the host PC via a simple dongle that plugs into the USB port or into the peripheral if UWB isn’t built in. The setup is automatic, making it fast and easy to use. Wireless USB connections to external hard drives are ideal applications, since UWB can easily handle lots of data that needs to move fast.
While the target for Wireless USB is any USB port device, some products are more likely than others to use them, like devices that have to transfer lots of data very quickly. Digital cameras hold huge files that take minutes or longer to download to PCs. With an internal Wireless USB link, the transfer can be super-fast and totally cordless. Speed also is a critical factor in video and audio transfers from devices like iPods.
Wireless USB additionally could be used to set laptops up in desktop docking stations. Instead of hardwiring for the mouse, keyboard, and monitor, you can use Wireless USB. Many laptop manufacturers already embed Wireless USB in their products. Dell, Fujitsu, Lenovo, NEC, Toshiba, and other key companies now offer it as a standard interface, making wireless peripherals common.
UWB OVER COAX
An interesting and innovative use of UWB involves the transmission of video, audio, and high-speed data over coax for home entertainment systems. Statistics indicate that about 90% of U.S. homes have installed cable TV coax within their walls. This medium can be shared with cable TV signals and used to distribute video and other signals within a home network.
One widely used standard, Multimedia over Cable Access (MoCA), is used in some consumer Internet Protocol TV (IPTV) installations. It can transmit data at a rate up to 175 Mbits/s using an orthogonal frequencydivision multiplexing (OFDM) scheme over 50 MHz of bandwidth above the usual cable frequency band of 875 MHz.
Sigma Designs has developed a chip set that puts the WiMedia standard on coax for home distribution of video. This eliminates some the problems with wireless distribution that can vary widely depending upon the home size, walls and ceilings, and other obstructions. It is reliable, and no new wires are needed.
For years, high-end sound equipment manufacturers have been seeking an ideal way to distribute stereo and surroundsound wirelessly to remote speakers. If you have ever attempted to install a 5.1 surroundsound system, which is common on audio systems as well as HDTV systems, you know the problem.
There are too many nuisance, ugly, and exposed wires in places that are hard to reach, so it’s UWB to the rescue. WiMedia company Radiient Technologies has developed a chip set and system called Roomcaster just for wireless audio (Fig. 2). UWB’s range is perfect for a single room.
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With a maximum data speed of 480 MHz, UWB is certainly an option for transmitting video from one place to another, especially compressed video. Since uncompressed video like 1080p needs a minimum of about 1.5 Gbits/s, UWB isn’t a good candidate—yet. But is uncompressed video really needed? Most video is compressed anyway by the cable, satellite, and IPTV companies, over the air or from a DVD.
With very impressive new compression standards like MPEG-4/H.264 that only require something like 6 Mbits/s, UWB is a natural. UWB is at least part of the solution to minimize the tangle of wires in the back of your TV set. WiMedia company TZero Technologies now offers a cool chip set implementing multiple input/ multiple output (MIMO) that facilitates reliable video transfers at a range of 20 m or so (Fig. 3). Or, try connecting your monitor to your other equipment via devices like Wireless USB to VGA adapters (Fig. 4).
The Wireless USB phenomenon now dominates UWB, and there are many fresh, new applications. But what’s next for this fast short-range technology? Current targets include game controllers and MP3 players. WiMedia company Artimi has a neat reference design using its UWB chips in a wireless LCD projector connection for laptops. And just for fun, how about a totally wireless USB flash drive?
Also, look for UWB eventually in cell phones. It’s an ideal radio for high-speed transfers of photos or video, and its interference potential is negligible as its high operating frequencies are well beyond the cellular spectrum and that of the 2.4-GHz band where Wi-Fi and Bluetooth reside. UWB could even compete with Near Field Communications (NFC), as NFC’s developers hope to see it in every cell phone for touch smart-card charges. Other short-range non-interfering applications are sure to develop. What’s your application?