Computerworld - As the Universal Serial Bus (USB) approaches its 13th birthday, like other adolescents it's eager to start thinking and acting independently. For the USB, this means chucking the cable and connecting to a wide variety of printers, keyboards, hard drives and other office peripherals without wires.
The idea behind Wireless USB (WUSB) is simple and seductive. Instead of connecting directly to a computer, WUSB uses ultrawide band (UWB) technology to wirelessly connect a USB peripheral to the system.
UWB spreads the data out over a huge swath of spectrum, rather than blasting a powerful signal in a small portion of the spectrum, as is the case with cell phones, Bluetooth and Wi-Fi. Because the signal is just above the background-noise level, WUSB is able to move a good amount of data without interfering with any of your other wireless gear, like a Wi-Fi router, a cell phone or a Bluetooth headset. In the U.S., WUSB uses the range between 3.6 GHz and 6.0 GHz; there are plans to go as high as 10 GHz in the future to boost bandwidth.
On paper, WUSB matches the USB 2.0 limit of 480Mbit/sec. of throughput, but don't expect this level of performance from most real-life setups. As is the case with most communications technology, WUSB's actual performance tends to be lower, closer to 25Mbit/sec. at a distance of 5 feet. That's about one-quarter the speed that a cabled USB connection provides.
To get the two devices to work together, the transmitter and base station need to be paired. This process takes about 10 or 15 seconds and only needs to be done once. The next time the two devices meet, they can automatically connect. WUSB has a practical range of up to about 35 feet.
At the moment, there are only a handful of WUSB products available. These include cable replacement kits, USB hubs and video extenders for linking a computer to a projector or monitor.
In-Stat analyst Brian O'Rourke forecasts that sales of WUSB devices will grow quickly over the next few years. In 2007, sales were a piddling 100,000 units, which he thinks could increase to as much as 190 million units by 2012.
A big step forward will be building WUSB into a generation of peripherals, including printers, scanners, media players and displays. That's starting to happen. Later this year, Imation Corp. will introduce a WUSB external hard drive, Toshiba will have a WUSB docking station and projectors and monitors will be available from Asus, Samsung and others.
Currently, there are about a dozen notebooks available with WUSB built in, but they are nearly all special-order items that are hard to actually get. As a result, every WUSB device comes with a USB dongle that contains a transmitter and plugs into the computer. The remote device itself -- which contains the WUSB base station -- is powered by an AC adapter; some of the WUSB products add external antennas that can be aimed to grab the strongest signal while others have them buried inside.
To see what's possible with WUSB, I collected several currently available WUSB devices: hubs by D-Link and IOGear; the Cables Unlimited Wireless USB Adapter Set; and two video kits: Imation's Wireless Projection Link and IOGear's Wireless USB to VGA kit. I tried them out using a Dell Vostro 1510 notebook (with which I used the supplied dongles) and a Fujitsu LifeBook A6220 notebook (which comes equipped with WUSB).
Wireless USB has great potential to cure desktop clutter and end the hassle of stashing cables under carpets or taping them to walls, but it's still in its infancy. In other words, don't throw your USB cables away just yet.
The beauty of the Wireless USB standard is that rather than having to buy new wireless equipment, you can plug your favorite wired USB peripherals into the wireless hub, and they're connected to your PC or laptop without a wire in sight.
I tried the wireless hubs and cable kit with nine USB peripherals at a distance of 5 feet from my Dell Vostro 1510 test bed. They included a Kingston 1GB USB drive, a Western Digital MyBook 500GB external hard drive, a Toshiba external DVD drive, a Logitech wireless mouse, a Brother 2170W laser printer, a Sony voice recorder, a Memorex keyboard, a three-port USB hub and an 8GB iPod Nano.
With the DVD drive connected, I listened to an audio CD with an ear to whether there were any dropouts, skips or muddled sound. Finally, with the CD still playing, I walked away from the WUSB product with a connected notebook in hand and noted where the system lost its connection. Then I walked back toward the hub to see if it automatically reconnected.
Finally, I measured the throughput for each hub kit using a Passmark USB2.0 Loopback Plug and Passmark's USB2Test software, which sends data out and times how long it takes to return to the notebook. The system logs nine tests every second for a minute and tabulates the results. These figures, however, represent the upper theoretical performance limit you can expect from the hub or cable replacement product.
To get a real-world result, I connected a 500GB Western Digital My Book USB external hard drive and moved a 209MB folder with 250 files in it and timed how long it took to move all the data to the notebook. For comparison purposes, I repeated the tests with the Fujitsu LifeBook A6220.
For the video, I connected each video kit to the Vostro 1510 notebook and a Dell 17-in. LCD monitor. (I repeated each procedure with a Vizio 47-in. TV and then used the Fujitsu LifeBook A6220 notebook that has WUSB built in.)
I used each device to extend and then mirror the notebook's desktop to the monitor. I then walked away from the transmitter and noted where it lost contact. Next, I walked back to see if the system would reconnect.
I watched online and DVD videos and looked for artifacts, delay or dropouts in the video.
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