Why Is Bluetooth Blue?
Let's start at the beginning: As you probably already know, Bluetooth is a wireless protocol maintained by the Bluetooth Special Interest Group. What you might not know is that it's actually named after a 10th century Danish king, King Harald Blatand (Bluetooth) who brought together parts of Scandanavia. This is what Bluetooth was designed to do, except it's bringing together devices—rather than Viking hordes—with a universal wireless standard. The symbol for Bluetooth, even, comes from the runes for Harald Bluetooth's initials, H & B.

Basic Details
Bluetooth is a short-range wireless setup design for personal area networks that rides on the 2.4 to 2.485GHz bands. The core of the radio tech is that it uses a frequency-hopping spread spectrum signal that bounces between 79 different frequencies, which makes it less prone to interference from other 2.4GHz devices in the area—you know, like everything nowadays. It's designed to be low power, but the standard has three different classes of strength, using more power to go farther. Most mobile stuff is Class 2, using about 2.5mW power for a range of 33 feet, but Class 1 will stretch out over 100 feet meters using 100mW.

Profiles, or Where It Gets Confusing
The Bluetooth spec is a series of profiles, which you can think of like capabilities. Devices have to have compatible profiles in order to make certain magic happen. For instance, the Advanced Audio Distribution (A2DP) profile describes how to stream stereo audio, like to headphones from an MP3 player. No A2DP, no stereo. There's a ton of them, from FTP (file transfer profile) to headset profile, which defines how a Bluetooth headset should talk to a gadget. You've also got core protocols, like object exchange (OBEX), which is what you lets swap files between Bluetooth devices, famously crippled by Verizon on some phones.

Bluetooth Spec Versions
• Bluetooth 1.0, in a word, sucked. The puny 1Mbps connection was split between data and voice, so you really only got about 700Kbps transfer rates (if you were lucky) and you could only tether to one device at a time.

• 1.1 fixed some of 1.0 and 1.0B's suckiness

• 1.2 is where it started getting actually better, bringing in Adaptive Frequency Hopping to make it more resistant to interference from the constant 2.4GHz maelstrom, and Enhanced Voice Processing, so it doesn't sound like you're talking through a cat blender. Backward-compatible with 1.1. The original RAZR had Bluetooth 1.2.

• Bluetooth 2.0 + EDR, hello speed, goodbye power. Ratified in 2004, data transfer rates were boosted to 2.1Mbps with Enhanced Data Rate, and power consumption was cut in half. It's the Bluetooth standard that made good headsets possible. Technically, EDR is optional, but what's the point without it? The iPhone is an example of 2.0 + EDR, as is the HTC Touch Pro and T-Mobile's Android G1.

• Bluetooth 2.1 + EDR added further enhancements to the Bluetooth 2 spec—better, faster pairing, with fewer steps and lower power slurpage still, depending on what you're doing. It also adds support for Near Field Communications (NFC), for completely automagical pairing.

Bluetooth 3.0 + HS and Bluetooth Low Energy
Oh hey, you made it. The Bluetooth Core Specification 3.0 High Speed was formally adopted a week ago.

The big deal is that has crazy fast data speeds of up to 24Mbps (fast for Bluetooth, that is), thanks to the fact it piggybacks on good old 802.11 Wi-Fi radio. The standard Bluetooth radio is used for the boring, low intensity part, like profiles and whatnot, but the data shakedown happens over 802.11 when you're doing things like wirelessly syncing music libraries, downloading photos to a printer or sending video files, so you're only using lots of juice when you need to. Unicast Connectionless Data is a feature that'll make devices more responsive (less lag, yo) and Enhanced Power Control will use power more smart and efficiently (so, using less of it, though transferring heavy files like whole music libraries is gonna suck on the power teet hard, obviously). No device has it now, but we should be seeing it live in the next 9 to 12 months, which isn't a bad turnaround, considering it took 4 years for the first Bluetooth 1.0 devices to show up.

At about the same time, Bluetooth SIG revealed Bluetooth low energy technology that will let devices sip power so slowly they can last more than a year on a single battery. It's slow like Bluetooth 1.0 and isn't voice capable, but will be super useful in monitors and sensors and those kinds of gadgets, letting them connect to bigger computers and whatnot.

So that, in a nutshell, is the wacky world of Bluetooth. See, it doesn't have to be just used by douchey business guys.

Still something you still wanna know? Send any questions about why the sky is blue, evil clown dentists or how Coke rots your teeth to tips@gizmodo.com, with "Giz Explains" in the subject line.

Besides making batteries go further (obviously in terms of idleness, since every wireless connection uses more juice to send more data) Unicast Connectionless Data makes gadgets more responsive over Bluetooth, and Enhanced Power Control will supposedly translate to less disconnects from shoving your phone in your pocket.

Too bad we'll have to wait nearly a year for the first Bluetooth 3.0 gadgets. I'd like a Bluetooth 3.0 mouse with built-in flash storage, electric razor and mini cooling fan. [PC World]

Dvice says that the new protocol will be less prone to disconnects, thanks to 3.0's new Enhanced Power Control, and according to the press release 3.0 will have wi-fi speeds, making it possible to transfer "an entire music library, a complete DVD, a vacation's worth of photos, all within seconds at the touch of a button and wirelessly will now be possible." I remain skeptical on that last bit, but I am excited to see just what's under the hood of updated tech in a few weeks. [Bluetooth via Dvice]

That kind of speed blows the doors off Bluetooth 2.0, which pokes along at a mere 721Kbps 2.1 Mbps. The new Bluetooth gets its exponentially faster speed by teaming up with ultra wideband technology (UWB). But there are other contenders using similar tech such as Wireless USB (also 480Mbps), and it's hard to tell how these various protocols will compete with each other. The way we see it, Bluetooth is for near-distance, or personal area networking and Wireless USB has farther reach. But with the increased distance of Wireless USB, what would be the point of a shorter-distance protocol such as Bluetooth? Looks like we might have a horserace on our hands. Commenters, thoughts? – Charlie White

Next-generation Bluetooth technology may hit market in 2007 [TG Daily]