Wednesday, April 29, 2009
Bluetooth 3.0 includes a provision to use it for remote control applications, where battery life needs to be long and cost needs to be low--prompting rival the rival RF4CE/Zigbee Alliance. The RF4CE specificaiton uses a 2.4-GHz radio like Bluetooth, but is specifically designed for low-cost wireless RF replacement of the cheap, plentiful infrared (IR) remotes that litter eveyone's living room today. To the RF4CE mavin, using Bluetooth for a remote control is like using a Cadillac to transport troops. Yet I personally use my Bluetooth phone to control the playback of my iTunes music library. The real question here is whether Bluetooth will replace RF4CE before it even gets off the ground, to which I answer no. After all, not everyone can afford to drive a Cadillac.-R.C.J.
The recently ratified Bluetooth 3.0 specification not only ups the wireless interface's speed to 25 Mbits per second. The spec also defines a new function called Unicast Connectionless Data (UCD), putting it in direct competition with RF4CE, the wireless remote control specification that merged last month with the Zigbee Alliance efforts to replace infrared remote controls. While the rival interfaces were originally designed for different applications, TV makers will have to choose between them. Bluetooth was considered too power hungry and its latency too high for remote controls, burning through a set of batteries in three months and delaying a second or more before registering a button push. However, the new UCD functionality in the 3.0 spec extends battery life to about four years and lowers Bluetooth's latency to milliseconds.
Posted by R. Colin Johnson at 7:41 AM