Try to remember what the booming short-range wireless technologies were 10 years ago. Nothing comes to mind except for garage-door openers, CB, and a few ISM (industrial-scientific-medical) radios. Since then, a deluge of short-range wireless technologies has descended on the masses.
Developments went from a yawn to hyperfrantic information overload. And there’s no stopping them, with short-range wireless devices now embedded in almost every electronic product. Bluetooth and Wi-Fi dominate such connectivity, but standards like Ultra-Wideband (UWB) and WiMAX are making progress.
Bluetooth
Bluetooth stands tall among the wireless standards simply because it leads the pack in worldwide device deployment. With chip shipments exceeding 1 billion, no other wireless technology comes close.
Half of today’s cell phones—which have the highest volume sales of any consumer product on the planet—contain Bluetooth for hands-free cordless connectivity to handsets. Bluetooth also is popular for other wireless connections in the automotive, consumer, PC, and PDA markets.
CSR is the leading Bluetooth chip provider, taking 60% market share. Its fifth-generation technology packs Bluetooth connectivity into a single chip. CSR offers versions with a multimedia processor for noise-cancellation software and various voice-processing applications. Other versions include a built-in FM radio.
The forthcoming 3.0 version of the standard will feature a UWB physical layer (PHY). These Bluetooth radios, which use the WiMedia orthogonal frequency-division multiplexing (OFDM) standard, should work in the 5-GHz range rather than the 3.1- to 4.9-GHz range of wireless USB UWB radios. The complete standard won’t be ratified until December, but expect some new Bluetooth applications that require data rates in excess of 100 Mbits/s, like video.
Ultra-Wideband
The first UWB products are a far cry from what was originally imagined. But the result is a new wireless technology with a solid niche, in this case wireless USB. Most companies that make UWB chips follow the WiMedia Alliance standard based on OFDM. Their products address the wireless USB applications of PC and laptop connectivity to peripherals, digital cameras, and other high-data-rate extensions (Fig. 1 and 2).
Since UWB has the potential to achieve 480 Mbits/s, it’s seriously being considered by companies seeking to integrate wireless video connectivity in consumer electronics. Despite its limited range, UWB certainly can support video. But can it deliver the required performance?
Nonetheless, UWB is a winner, and future developments will further broaden its usage. In fact, the Bluetooth Special Interest Group has made UWB its next PHY of choice. Future versions of UWB will exploit bands beyond 4.9 GHz, opening new possibilities and providing versions that are more compatible with the spectrum and regulatory limitations of other countries. What once was considered an exotic wireless technology is turning into one of the most flexible.
Wi-Fi
Next to Bluetooth, Wi-Fi is by far the most successful and widely deployed short-range wireless technology. What laptop doesn’t contain an 802.11b/g transceiver that lets you get online via the hundreds of thousands of hot spots worldwide or through your own wireless home network?
Research firm ABI indicates that at the end of 2006, there were 147,300 Wi-Fi hot spots worldwide. Europe leads the way—and that doesn’t include the hundreds of thousands of regular local-area-network (LAN) access points.
Work continues on the next version of Wi-Fi, designated by the IEEE as 802.11n. It promises better than 100-Mbit/s service with greater reliability thanks to its multiple-input multiple-output (MIMO) antenna technology. A first draft of the standard is complete, but final details are being ironed out by the IEEE Task Group.
In the meantime, chip and wireless LAN equipment companies are going ahead with pre-n or draft-n versions of their products. The Wi-Fi Alliance also initiated a testing and certification procedure of the draft-n products that will begin in July this year. Final ratification isn’t expected until early 2008.
The big news surrounding Wi-Fi is the rapid build-out of municipal mesh networks. Cities across the U.S. have installed mesh Wi-Fi networks open to citizens, travelers, and city employees. Mesh topology lets individual nodes, with their usual restricted range of about 300 feet, talk to one another and relay data from one to another.
As a result, super-low-cost nodes can cover many square miles. Over 350 new mesh Wi-Fi networks were installed in the past 30 months, according to Karen Hanley of the Wi-Fi Alliance. Expect that number to grow.
Dual-mode cell phones have taken to Wi-Fi too, providing Voice over Internet Protocol (VoIP) calling using the Session Initiation Protocol. They’re available now, and cell-phone network providers are testing out the service. Problems such as handoffs between cell and Wi-Fi, high handset power consumption, and using one rather than two phone numbers still must be resolved. Still, it could be another profitable niche for Wi-Fi.
Reprints
