The iPhone 4S Is the First Bluetooth 4.0 Phone

Among the many novel technological features of the iPhone 4S like Siri and the A5 processor, one that's gotten little attention is that it's the first cell phone to feature Bluetooth 4.0, which makes the iPhone compatible with a whole new category of low-energy wireless devices. That means the phone will be able to talk to things like special thermometers and scales, which previously couldn't have Bluetooth technology since it consumed too much power.

Bluetooth 4.0, which was announced in April last year, expands wireless abilities to many different kinds of products. Now not only can your phone and laptop have wireless abilities, so can your wristwatch, medical bracelet, or anything you can think of that includes a battery. Since the low-power Bluetooth 4.0 radio sips power, devices that previously had to send their data only when connected manually can now do so over the air. All they need is a Bluetooth 4.0-compatible device, like the iPhone 4S and the newly announced Motorola Droid RAZR, on the other side.

Although Bluetooth 4.0 expands the definition of Bluetooth, it risks making things more confusing, since the spec actually includes two different kinds of devices. First, there are the low-energy devices that now have low-power Bluetooth radios. But they need to be designated separately from the traditional products—phones, tablets, and PCs, mainly—that those low-energy gadgets will talk to.

In the hopes of clarity, the Bluetooth Special Interest Group (SIG) today introduced what it calls "Smart Marks," two different labels for the two different classes of Bluetooth devices. Those low-power doodads will now be called Bluetooth Smart devices, while Bluetooth 4.0 devices like your cell phone fall into the category Bluetooth Smart Ready.

The main physical distinction is the radio. Bluetooth Smart devices will have just a single-mode low-power radio while the Smart Ready ones must have a dual-mode radio that does both low and normal power. In addition, a Smart Ready device must be capable of downloading new software to keep its Bluetooth profiles up to date. If it helps, think of the Smart Ready device as a mothership, while the Smart devices are shuttlecraft.

In addition to the iPhone 4S and Motorola RAZR, both the MacBook Air and the Mac Mini include Bluetooth 4.0. It's also on board the Acer Aspire Ultrabook and a few phones recently launched in Japan, the Bluetooth SIG said.