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PC industry causes Bluetooth U-turn on 1.2 spec: it's approved after all

The PC industry urgently needs Bluetooth wireless chips that don't interfere with WiFi. It's almost certainly because of the sense of urgency involved that the Bluetooth SIG has had to change its mind, and has approved the new 1.2 version of Bluetooth.

As reported here, earlier, there were parts of the standard which couldn't be approved by the expected September deadline. There were, also, a lot of features which worked, and were urgently required. It was decided to rewrite the spec.

The main reason for the panic was Adaptive Frequency Hopping, which allows Bluetooth to avoid interference with WiFi (they use the same 2.4 GHz frequency). It was one of these features which had been tested and worked, but couldn't be used under the terms of the Bluetooth patents.

We may still not get Bluetooth products with adaptive frequency hopping before the end of 2003, but the earlier fears that the version 1.2 specification might not be even approved until February, have now been quashed.

The work of changing the spec is what took the time, according to Jennifer Bray, a consultant to Cambridge Silicon Radio - whose Bluecore chips a rebuilt into almost every notebook PC if it has Bluetooth.

The problem, said Bray, was that in order to get the 1.2 spec approved, prototypes had to be tested. But relatively few silicon builders had built silicon using new features like scatter mode and extended SCO (synchronisation connection oriented) - and this meant that compatibility testing was pretty much restricted to seeing if CSR silicon would conform to itself.

Compatibility testing, however, is essential to approval.

"We had to take the un-approvable features out of the spec," said Bray. "That was going to take time, and it was expected that it would take a lot longer than it did." That was why Anders Eglund issued the notice (first published in "Incisor" magazine) that approval would not be possible for some time.

However, the estimate for the delay was based on the assumption that SIG members would not treat the task of editing the spec with as high a priority as in fact turned out to be the case. Staff who would normally have been expected to put in a heavy workload in their normal design jobs, were allowed to spend the hours on making sure that version 1.2 had no references to the unapprovable features.

As a result, a task which was regarded by optimists as "unlikely to be done till December at the earliest" is actually complete, and the SIG has announced that approval.

Products that actually work to this new standard exist, but turning on the new features, getting them tested by the SIG, and having final product approval, is still a bureaucratic process, and it may still be January before the first 1.2-compliant products appear.

They will, almost certainly, be notebook PCs, where the requirement for co-existence between Bluetooth and WiFi has been critical to some lost sales. The technique of adaptive frequency hopping extends the normal frequency hopping by actively avoiding channels being used by 802.11 wireless devices.

It's pretty clear that the squeals of panic from the PC industry were a major incentive to the SIG members, to get this problem treated as high priority.

Extended SCO is unlikely to be badly missed until people start wanting to create stereo Bluetooth headsets and speakers for high fidelity purposes.