CNET's quick guide to Bluetooth headsets

If you think your choice of cell phones is already too extensive, choosing a headset can be just as bewildering. With so many styles available, headsets are quickly becoming fashion accessories in their own right. And as their use proliferates, especially with the advent of hands-free legislation for drivers, you now can go far beyond clunky, tangle-prone wired headsets. Bluetooth headsets, which offer a convenient and user-friendly wireless connection between a headset and a Bluetooth-enabled cell phone, are now an "in" feature for frequent gabbers. But until recently, there weren't enough capable phones to match the wide array of headsets. Fortunately, those numbers are beginning to even out, and you can even buy adapters that let you use a headset with a non-Bluetooth phone.

To help you find the best fit, CNET's editors have compared several models on the market today and tested the headsets with a variety of phones from several manufacturers.

What's in a name?
In case you were wondering, Bluetooth gets its name from a 10th-century Danish king, Harald Blatand (or Bluetooth) who unified Denmark, Norway, and Sweden. According to legend, he had an affinity for teeth-staining blueberries. Oh, and the logo combines the runic alphabetic characters for H and B.

What is it?
Bluetooth is probably the most misunderstood child born in the wireless age. Beyond its oddball name, what it can do and how it works isn't exactly common knowledge. IDC now estimates there will be more than 100 million Bluetooth devices worldwide by the end of the year, and In-Stat/MDR expects a compound annual growth rate of 60 percent from 2003 to 2008. Truly, you now can find Bluetooth in an array of products: wireless phones, PCs, cameras, GPS devices, handhelds, and even cars.

While it may sound complicated, Bluetooth works in a simple manner. First developed by Ericsson, then formalized in 1999, it provides a way for different devices to communicate with each other by sending data via a secure, low-cost short-range radio frequency. Using the technology, cell phones can talk to headsets, PCs can talk to printers or keyboards, and handhelds can talk to each other without any wires. Up to seven connections can be made at one time, at a speed of 1Mbps. But even that's not the whole story. With the introduction of the Bluetooth-capable 2004 Toyota Prius and Lexus S430, drivers now can use their cell phone via the car's audio system and onboard navigation screen. All that's needed for any two Bluetooth-enabled devices to work is for them to be paired--normally, a hassle-free "handshaking" process for establishing a connection that takes seconds and can be found in most wireless connectivity menus.

While it may resemble Wi-Fi in its use of the same frequency range (the 2.45GHz band), the similarities stop there. Bluetooth covers one-fifth the total range of Wi-Fi, and Wi-Fi requires more-expensive hardware and reaches greater distances. Additionally, Bluetooth lets two devices communicate with each other while Wi-Fi establishes a wireless network.

Pairing up
Before you start talking, you do need to know a few facts. Bluetooth has a range of 30 feet (10 meters), and the devices in question must use compatible versions of Bluetooth. The majority of products currently in the marketplace work on Bluetooth 1.1. (Two previous versions, 1.0 and 1.0B, were plagued with compatibility issues and have since been discontinued.) The Bluetooth Special Interest Group (SIG), a trade association and development group, is releasing newer versions that promise several upgrades and backward compatibility. The most recent release, Bluetooth 1.2, includes the addition of an anonymity mode, which masks the hardware address of the device to protect from identity snooping and tracking, and adaptive frequency hopping, which cuts interference by avoiding crowded frequencies. And set for release possibly by the end of the year is Bluetooth 2.0. Among its expected enhancements are narrowband channels, which will enable messages to be broadcast to a high number of devices without the pairing process, and higher connection speeds of up to 12Mbps.

Be secure
As with any wireless device, Bluetooth has some some minor security concerns. The SIG has admitted that bluebugging, where a hacker secretly accesses a phone's commands (such as eavesdropping on conversations), and bluesnarfing, where a hacker can access a phone's data--such as the contacts--are possible, yet the group downplays both actions. While they work through Bluetooth, they also require the hacker to use a PC and to be within range of the victim. Still, Nokia and Sony have said these issues affect only older handsets that are available mainly outside of the United States, and Nokia is promising a software upgrade. To help combat both, Bluetooth devices can be locked with a code or simply turned off or put in Hidden mode when not in use. Another concern, depending on how you look at it, is bluejacking. This involves creating an often flirtatious introductory message, then sending it to another Bluetooth-discoverable phone nearby as a text message, only you can't get charged for it as you would a typical text message sent over a wireless data network.