It wasn't that long ago, but it is so easy to forget the state of play before a consortium of companies including IBM, Intel, and Microsoft introduced Version 1.1 of the Universal Serial Bus, or USB, in September 1998. Do you remember that junk drawer full of cords that were hopelessly ill-suited to anything but the items with which they were packaged, but you kept them "just in case"? When USB came along, and then USB 2.0--which, in 2002, increased the standard's data-transfer rate from 12 megabytes per second to 480 MB/s--the result was a connection that worked every time without any heroic action on the part of the user and allowed PC and Macintosh users to share peripherals for the first time. Simply put, USB has become the de facto connection standard for consumer electronics.
Now USB is poised to get even better. Starting this year, electronics manufacturers will introduce products that cut the cords tethering USB peripherals to their hosts. That's a lot of cords, especially when you consider analysts' prediction that there will be more than 3.5 billion USB interfaces included in consumer electronics by 2008. The wireless USB hub, to be introduced this spring by consumer electronics manufacturer Belkin Corp., in Compton, Calif., will put a base station for plugging in your peripherals exactly where you want it. Also available this spring, will be a USB extender from Gefen Inc., in Woodland Hills, Calif. Units plugged into the host and the peripheral will talk to each other over distances as far as 10 meters.
What's the big deal? With wireless USB, no longer will you have to deal with the inconvenience of getting down on all fours under your desk to unplug one device so you can plug in another. Going wireless will also allow effortless networking of electronic devices. Gone will be the clumsy workarounds you have to employ when you want to use a stationary, networked printer to print from your laptop or deliver a PowerPoint presentation using unfamiliar A/V equipment. You will be able to simultaneously transfer digital images from your still or video camera straight to a printer or external hard drive, play music directly from your iPod to your stereo speakers, and send a scanned image to your computer--all without any physical connections.
Initially, wireless USB hookups will happen via a dongle--a small device that plugs into a computer to authenticate software, expand memory, or facilitate communication--connected to the host's USB port. The dongle will exchange signals with a USB hub or a transceiver plugged into a peripheral. Soon after, computer and device makers will start embedding wireless USB interfaces in their products, making the dongle-and-transceiver setup unnecessary except with legacy computer systems and devices.
That's the good news. But for every silver lining there's a cloud. The confidence that comes from knowing exactly what you're getting when you see the letters USB may not hold for its wireless incarnation--at least not in the early going. Here's why:
Wireless USB will transfer data over a short-range, low-power, high-data-rate communications technology known as ultrawideband (UWB). In this approach, the transmit power of the digital signal is spread across a broad swath of the spectrum, emitting just a tiny amount in each frequency. Although UWB uses portions of the spectrum "owned" by other users, interference is limited by the fact that its low power output makes its transmission on any given frequency indistinguishable from noise.
Two camps--one led by Freescale Semiconductor Inc., based in Austin, Texas and an offshoot of Motorola Inc., and the other by Intel Corp., in Santa Clara, Calif.--are vying for the right to call their versions of UWB the worldwide standard. The fight over which group's technology would be named the IEEE 802.15.3a UWB standard dragged on for more than two and a half years [see "Ultrawide Gap on Ultrawideband," IEEE Spectrum, January 2004]. Then, in January 2006, the IEEE standards group finally acknowledged that the stalemate would not be broken, and it voted to disband. Now both UWB technologies--and the technologies that they enable, such as wireless USB--will have to fight it out in the marketplace. Until consumers declare a winner, there will be two incompatible types of wireless USB.
Freescale was the first to produce chips that made wireless USB over UWB possible. At the 2006 International Consumer Electronics Show in Las Vegas in January, Belkin and Gefen demonstrated prototypes of the aforementioned wireless USB devices. Belkin's four-port hub communicates with a dongle containing a UWB radio made by Freescale. USB devices plug into the hubs with cords, but the advantage is that, because the hub has no physical connection to, say, a computer, it can be placed where it is most convenient for the user. Belkin has announced that its hub will sell for US $129. Gefen, whose product dispenses with wires altogether because the transceiver plugs directly into the peripheral's USB port, hasn't released any price information. Industry analysts note that these devices will start off a bit pricey, and first adopters will pay a lot. But as demand picks up, prices will fall with greater production.
Each side in the wireless USB battle makes valid arguments for why its approach is best. Freescale says its aim is not to change a thing. The company wants its wireless USB to maintain the universal compatibility and simple plug-and-play utility that are the hallmarks of wired USB. Jerry Lynch, Freescale's director of applications engineering and product implementation, says the company's decision to take the wired USB 2.0 protocol and place it on a wireless medium will make for the smoothest transition to cordless USB. (Freescale doesn't use the term "wireless USB," because the phrase is part of the name adopted by the rival camp; instead it has adopted the phrase "Cord-Free USB" for the industry group promoting its products.) Lynch says Cord-Free USB will "allow anything that is certified USB to work without a cable--and the transition is seamless to the user." He points out that the Intel camp's competing technology is "an entirely new standard that will force users to download new drivers and get new hardware."
The other flavor of wireless USB, to which Lynch was referring, is Certified Wireless USB, the one backed by the USB Implementers Forum, the industry group led by Intel. This group, under the name Multiband-OFDM Alliance (now the WiMedia Alliance), pushed for the adoption of orthogonal frequency division multiplexing, or OFDM, ultrawideband technology (in opposition to Freescale's direct sequencing method) as the IEEE standard. So far, products based on WiMedia technology have yet to appear on the market. But Jeff Ravencraft, a technology strategist at Intel who is also president and chairman of the USB IF, is confident that Certified Wireless USB's features will make it the consumer choice.
Ravencraft doesn't disagree with the characterization of Certified Wireless USB as a different standard from USB 2.0. But he says the benefits these changes provide are well worth it. "We built the protocol from the ground up to tailor power management, security, data throughput, and isochronous [time-uniform] support for applications such as streaming HDTV specifically for the wireless environment," says Ravencraft.
One important virtue of Certified Wireless USB, he says, is that each host can talk to 127 different devices. That is, one dongle will trade signals with up to that many peripherals as long as they have wireless USB transceivers attached. He notes that with Cord-Free USB devices, the host-receiver set is paired at the factory so that one host connects to only one transceiver. Although Freescale's Lynch says the same type of multiplexing can be done with the Cord-Free USB products from Belkin and Gefen by plugging, say, a four-port hub into each of a single hub's ports, this setup would require users to buy multiple hubs.
The combatants naturally disagree on a number of other fronts, including which technology is best suited to meet coming regulatory mandates in Europe and Asia. Contemplating the situation, Robert F. Heile, an IEEE Senior Member who was chair of the recently disbanded IEEE ultrawideband working group, says, "Let them duke it out in the marketplace."
Heile told IEEE Spectrum in January 2004 that he wanted to see both sides proceed with production of devices based on their proprietary specifications "so we can get the experience we need to write an even better standard." It looks as though he is getting his wish.