Which of the two rival Ultra Wideband wireless technologies will the next version of Bluetooth be based on? The question may seem academic, as both offer similar promises: ranges of a few feet, and a data rate of around 100 Mbits/sec--enough to stream DVD-quality video. But it matters a great deal to the companies involved, and more importantly, to anyone thinking of using the technology. Business and consumer products using each of the two incompatible variants will appear over the coming months, and Bluetooth’s endorsement could decide which ends up as VHS and which as Betamax.

Right now, the Intel-led Wi-Media Alliance looks like a likely winner. It held its first successful interoperability tests earlier this month, with products from five different companies working together. The computer industry has also adopted its spec for wireless versions of the USB and Firewire (IEEE 1394) interfaces. At the Alliance’s meeting Thursday in San Francisco, the keynote speaker was Michael W. Foley, executive director of the Bluetooth Special Interest Group (SIG), the association of more than 4,000 vendors that sets the Bluetooth standard.

Foley won’t commit the SIG to a decision yet. “We're talking to both groups,” he says. The other group is the UWB Forum, led by Motorola spin-off Freescale. Though it hasn’t attracted as much vendor support, it's beating Wi-Media to market, with radio chips already shipping to device manufacturers. The IEEE formally disbanded its attempts to unite the two standards last month.

The first UWB products from each group will be replacements for USB extender cables--radio dongles that can connect a PC’s USB port to a peripheral such as a thumb drive or a printer. The long-term aim is to eliminate the ports and dongles altogether, building UWB straight into everything. Consumer electronics are the largest market, but the technology is also aimed at business tools such as PDAs and BlackBerrys, and even PC components like monitors.

Bluetooth is quickly becoming standard on cell phones, which in turn are beginning to replace other business and consumer devices. However, the present spec maxes out at 3 Mbits/sec--fast enough to play MP3 files in real time, but not to transfer large photo albums or PowerPoint presentations in real time. The hope is that by combining the two, Bluetooth will get a speed boost, and UWB will get a larger market share.

But some electronics vendors are concerned that neither existing version of UWB is good enough. Linksys, for example, will not include UWB until the data rate is sufficient for the High-Definition Multimedia Interface standard, which carries video without compression. “HDMI needs a gigabit,” says Malachy Moynihan, VP of home networking at Linksys. “That’s why Wi-Media is taking so long. People realized it would be too slow.”

Whichever group's proposal the Bluetooth SIG picks, actual UWB-based Bluetooth products are still about two years away. The SIG’s Foley estimates that the UWB Bluetooth standard will be finalized in fall 2007, with chips shipping a few months later.

Before that, the SIG will release an interim version aimed at improving audio performance and simplifying security. Bluetooth already has a QoS mechanism that can prioritize voice over data, but it works best with the low data rates of cell phone calls .The update aims to boost sound quality when Bluetooth headsets link to laptops running VoIP software, or stream stereo music from MP3 players.

New Bluetooth devices will start to support the interim spec in summer 2006. Unlike the planned UWB version, it doesn't require a new radio, so a software upgrade will be available for some existing users. But not for all of them. "It depends on how the phone is made," says Foley. "Phones with flash memory can be upgraded, but some manufacturers cut costs to the bone and use ROM instead."