Bluetooth 3.0 arrives

The Bluetooth 3.0 specification has finally been ratified.

The main new feature is the Alternate MAC/PHY (AMP), that lets Bluetooth piggyback on Wi-Fi for high speed data transfers. The way it works is that applications write to the traditional Bluetooth Profile APIs, and connections are negotiated using the traditional Bluetooth radio. But then for high-speed data transfers the system switches to a direct peer-to-peer Wi-Fi session. This enables things like bulk syncing of photos from your phone to your PC, or streaming uncompressed CD stereo audio to wireless loudspeakers.

I wrote about Bluetooth AMP before, wondering why it retained a dependency on Bluetooth radio. The answer is that in idle, listening mode waiting for activity, Bluetooth is more power efficient than Wi-Fi, while Wi-Fi is more power efficient for bulk data transfers. This makes Bluetooth’s other next big thing, LE (formerly Wibree), an interesting complement to AMP: for power efficiency Bluetooth devices will reside in two modes, very low power idle mode (LE), and Wi-Fi mode when transferring data.

The Bluetooth 3.0 specification talks about 802.11 rather than 11g or 11n, since 802.11n is not yet ratified, but some of the companies involved will be supporting draft 802.11n anyway.

From an industry point of view there are several interesting aspects to this announcement, among them:

  • Atheros’ ascendence. Atheros, a leader in Wi-Fi, only recently got into the Bluetooth market, and currently only plays in the PC Bluetooth market. It dabbled in headset Bluetooth and got out, and has not yet announced Bluetooth for handsets. So Atheros is a minor player in Bluetooth, eclipsed by CSR and Broadcom, and several others. But Kevin Hayes of Atheros was the technical editor for the 802.11 Protocol Adaptation Layer of the Bluetooth 3.0 specification, and Atheros supplied the video and the demo of AMP at the 3.0 announcement event.
  • Potential movement of Wi-Fi into feature phones. Handset makers slice the market into four main segments: ultra low cost phones, basic phones, feature phones and smart phones. Wi-Fi is now pretty much ubiquitous in new smartphones, but effectively absent in all other types of cell phone. But feature phones have music and cameras which generate exactly the data that Bluetooth 3.0 was designed to sync with PCs, so Bluetooth 3.0 provides a motivation to handset manufacturers to add Wi-Fi to their feature phones. This will vastly boost the Wi-Fi attach rate in 2010 and beyond.
  • Another nail in the coffin of UWB (Ultra Wide-Band). In its original conception, AMP was to use WiMedia’s flavor of UWB. Later Wi-Fi was added to the mix, and now UWB is absent from the spec. UWB has so far failed to meet its performance expectations, and rather than fix it the WiMedia Alliance threw in the towel in March 2009. I suppose it is possible that the few companies still toiling away on fixing UWB will eventually overcome its performance woes, and that it will get adopted into the Bluetooth specification.

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