Bluetooth-enabled devices shown here included headsets, mobile phones, PC cards, electronic pens, in-car systems, video cameras, mobile music players and entertainment robots. "We are convinced that Bluetooth will change the consumer world, adding simplicity, friendliness and versatility [to consumer devices]," said Hiroshi Yoshioka, vice president of the Personal IT Network Co. at Sony Corp., in an opening keynote speech.

Broadcom Corp. too was apparently convinced of the importance of Bluetooth, bidding $440 million earlier this week for startup Innovent Systems Inc. (El Segundo, Calif.), a Bluetooth device designer. Innovent is the second company with Bluetooth technology that Broadcom has acquired, follwing its May acquisition of Pivotal Technologies Corp. (Pasadena, Calif.).

Anders Edlund, marketing director for Bluetooth at Ericsson Mobile Communications, acknowledged that the Bluetooth spec was intentionally written in such a way as to allow unusual silicon designs such as CMOS RF, with the expectation of further silicon integration in the future. But as a result, he said, many chip companies had to start their RF designs from scratch and many "underestimated the complexity of baseband design."

Although the Bluetooth version 1.0 spec came out in July 1999, the final test specification won't be completed until the end of this year. Lacking the details on test equipment, the Bluetooth special interest group (SIG) now offers an intermediate qualification process under which relatively relaxed interoperability testing is done against the so-called "Blue Units" system developed by Ericsson.

Intense debate

At a time when so many companies still need to correctly implement Bluetooth 1.0, the SIG members are reluctant to discuss details of version 2.0. "The spec is most likely to be released by the end of this year," said Edlund, but its rate is still under intense debate. Different parties are reportedly backing everything from 2 to 20 Mbits/second. In Edlund's view, the most important new function in version 2.0 will be "the automatic handover to the next access point" in voice applications.

Meanwhile, developers are concerned about how Bluetooth may play — both from a technology and a market perspective — with two other wireless nets in the 2.4-GHz ISM band, HomeRF and 802.11. Bluetooth offers 721-kbit/s data rates at a range of up to 10 meters, against 1.6 Mbits/s for HomeRF and as much as 11 Mbits/s for 802.11b. HomeRF and 802.11 also support transmission over considerably longer distances, albeit at a cost of additional power and die size.

Some developers said last week that if HomeRF does not get an OK from the Federal Communications Commission to extend transmissions to 10 Mbits/s, Bluetooth and 802.11 may split the market for wireless LANs. However, the two nets face some interoperability issues that are a particular concern for notebook computer makers whose products might use both links, said David Lyon, chairman and chief executive officer at Silicon Wave (San Diego), a chip company specializing in RF ICs.

When Bluetooth and 802.11b devices are used in close proximity, competing signals can cause a dramatic reduction in throughput, resulting in a much slower data rate and shorter transmission distances. Some industry players indicate that they expect a solution to arrive before the end of the year in the form of a high-level software layer that sits above Bluetooth and 802.11b.

The 802.11 net usually bears the brunt of the contention problems when the two collide. "We made sure the Bluetooth spec is extremely robust, withstanding interference," said Ericsson's Edlund.

That's because Bluetooth uses a narrowband fast-frequency-hopping scheme with a random-hop pattern. But 802.11 depends on direct-sequence spread-spectrum hopping. Hopping at a rate of 1,600 hops/second, Bluetooth can easily evade interference that could swamp 802.11, said Lyon.

While Bluetooth and 802.11 industry players have set up separate working groups to take a hard look at the issue, a few companies are claiming to be close to solving the difficult problem on their own. Silicon Wave, for one, claims to have a proprietary technology — "some extra thing we think we can help the industry," said Lyon.

By partnering with unnamed companies, "We hope to come up with recommendations before the end of this year," he said. "Our hope is that the solution would be on the software layer high above 802.11 and Bluetooth specifications," so that few if any changes will be necessary in hardware. Lyon, however, quickly added, "We are not making promises right now, though."

Lucent Technologies also claims to have "some thoughts" on managing graceful degradation between 802.11 and Bluetooth. As a player in both industry groups, "We have some intellectual property we think we can contribute," said Paul Kan, strategic marketing manager for Bluetooth at Lucent's Microelectronics Group. Elsewhere, Intel and Microsoft said they would cooperate on a software environment to bring Bluetooth to the PC in a standard way.

— John Walko of Electronics Times contributed to this report.