UWB and Bluetooth roadmaps gain clarity

Bang! Last January with the IEEE's 802.15.3a task group members voting to get out of the high data rate UWB standards business, the two special interest groups -- the UWB Forum and the WiMedia Alliance -- were off to the races. The prize being market acceptance of a single radio standard for high data-rate, wireless, personal area networks.

Winner takes all. The UWB Forum, with Freescale as its leader, was championing Direct Sequencing-UWB as the better UWB PHY specification. The WiMedia Alliance said that multiband orthogonal frequency-division multiplexing would make for a better specification. The two technologies are incompatible. Both cannot be incorporated into the same standard, whether that standard be a wireless USB network or a wireless Firewire network, or Bluetooth.

Therefore, a giant step in winning the race was having the Bluetooth SIG with its 4,500 associate- and adopter-member companies selecting one or the other technology as basis for its next-generation, high data-rate products.

In last February's column, I talked about the Bluetooth SIG found itself in. It needed to define a way to boost the standard's 3-Mbps data rate to a much higher rate if Bluetooth devices were to survive beyond the next couple of years. Last year the SIG announced that it would go with UWB, but not with which technology. The SIG wanted more time to see which technology would win in the market, and it was waiting to see which technology the IEEE 802.15.3a task group would pick.

But the IEEE task group reneged. It didn't announce a preferred technology before voting to dissolve the 802.15.3a project. The Bluetooth SIG lost a significant criterion in its selection process.

While the UWB Forum products seemed to be getting to the market first, the WiMedia Alliance specification were gaining credibility through the standards process of Ecma and ISO. However, the Bluetooth SIG needed to make a choice soon if it was to stay on schedule and publish its Seattle release of the Bluetooth Core Specification in 2007.

Then (to oversimplify the sequence of events), CSR 'made' the decision for the SIG: In February CSR announced that it was backing the WiMedia Alliance's technology. And since CSR makes more than half of all the Bluetooth chips in the world, including those made by OEM licensees, its choice to go with WiMedia Alliance certainly moved the Bluetooth SIG in that direction as well.

By the end of March, Bluetooth SIG announced that it selected WiMedia Alliance's UWB technology. A few days later, Freescale announced that it was pulling out of the UWB Forum and going its own way with its 'Cable Free' version of an ultra wideband specification. The UWB Forum lost its major silicon provider and most visible proponent. It would appear that the UWB Forum has lost the race.

Having the race tilted in favor of one technology versus another is a boon for test equipment vendors as well. Last year the USB Implementers Forum also selected WiMedia UWB for its Certified Wireless USB specification. Coupled with the Bluetooth SIG's decision, the WiMedia Alliance is now positioned to service the majority of wireless, consumer devices. While large test equipment vendors have the resources to hedge their bets and belong to both UWB special interest groups, smaller T&M companies need to hold off placing their bets until they feel comfortable with which technology will win.

Last March WiMedia held its second formal interoperability testing event, where six of its PHY vendors -- Alereon, Realtek Semiconductor, Staccato Communications, WiQuest Communications, Wisair and TZero Technologies -- tested their chip-level implementations.


Agilent Technologies, LeCroy and Tektronix performed the analytical measurements, including error vector magnitude, power spectral density and signal quality measurements.

'Interest in interop events is steadily increasing, and the key players, such as testing experts and chip manufacturers, are participating heavily,' said Brad Hosler, chairman of the WiMedia Alliance certification and interoperability committee. 'Execution of these test processes lays the groundwork for the WiMedia Alliance certification program scheduled to roll out this year. There is terrific momentum behind this process.'

Other test equipment vendors including Advantest and Rhode & Schwarz already belong to WiMedia Alliance. Others will soon be joining or at least placing their bets and developing testing equipment later this year. Good news for developers of Bluetooth and wireless USB products.