The Specs Explained
As of this writing, the most current Bluetooth specification is Bluetooth 4.0. This new version promises more-frugal power consumption. "Low energy is the hallmark feature of this specification," says Michael Foley, executive director of the Bluetooth Special Interest Group (SIG).
The previous version, Bluetooth 3.0 + HS, allowed the Bluetooth protocol to piggyback on 802.11 Wi-Fi when you needed to take care of more-demanding tasks such as sending video from your camera to your TV.
Version 4.0 became final in July 2010. Products supporting the new spec should reach the market this year.
Foley predicts that the first crop of products incorporating the new spec will be "proximity-type devices." Such a product might be, for instance, "a key fob that will alert you if you accidentally leave your phone behind." As for other product classes, Foley expects "personal monitoring devices, like heart rate monitors, or personal fitness devices, like pedometers." He says that Bluetooth 4.0 will enhance home entertainment markets, too, along with security, automation, healthcare, and sports and fitness.
Bluetooth Standards: Old and New
Right now, we're seeing plenty of new cell phones, headsets, and car speakerphones that support earlier Bluetooth specs--primarily Bluetooth version 2.1 + EDR (and to a lesser extent, version 2.0 + EDR). Earlier in 2010, Samsung rolled out its Wave S8500, one of the first phones to support Bluetooth 3.0, in Europe. (On the computer front, some PC makers, including Dell, offer laptops with Bluetooth 3.0 support.)
All of the more recent Bluetooth versions are backward-compatible. So if your phone supports version 2.0 but the headset you choose supports 2.1, for example, the two devices will still work together; you just can't benefit from 2.1's enhancements (such as faster pairing), as both devices must support the newer spec for the added features to have effect. Conversely, be aware that, depending on your phone's operating system, you may not be able to take advantage of all the features that a particular headset or speakerphone unit promises. For instance, if your phone does not support automatic phone book transfers, you'll have to transfer your contacts' information manually via Bluetooth. Additionally, if you own a phone with Android version 2.1 or earlier, you will probably have trouble using some car kits' voice commands. And if your iPhone doesn't run iOS 3.0 or newer, you can't enjoy stereo A2DP Bluetooth support.
Development and licensing of the Bluetooth specs are the responsibility of the Bluetooth Special Interest Group (SIG), a trade association that consists of companies in various industries, including telecommunications, computing, automotive, and networking.
Bluetooth version 4.0: Products supporting this spec will enable very low battery use. The new specification will greatly affect low-tech gizmos, such as watches and pedometers, that run on button batteries and are designed to last for years. Computers, phones, cameras, and headsets, on the other hand, are on the high-power end of the Bluetooth spectrum.
Bluetooth version 3.0 + HS (High Speed, as in higher data rates): This spec will clamp onto a Wi-Fi signal when handling larger chunks of data, so you can download scads of photos or synchronize your music library, for instance. It also promises to give you longer battery life, better security, and beefed-up power control. This should result in fewer instances of dropped connections in Bluetooth headsets and in-car speakerphones, for example.
Bluetooth version 2.1 + EDR (Enhanced Data Rate): This version of Bluetooth offers beefed-up security, and it's designed to let you breeze through the pairing process without the need to enter a PIN. All you have to do is turn on the headset and then select 'Add Headset' from your phone's menu; your phone and headset will find each other and connect through an encrypted link.
Bluetooth version 2.0 + EDR (Enhanced Data Rate): Version 2.0 (released in 2004) requires you to go through a multistep procedure to pair a headset with a phone. With the headset turned on, your phone must search for and recognize the headset; and then to connect to it, you have to punch in a passkey (typically four zeros).
The "EDR" portion of the spec means faster transmission speeds and lower power consumption. For exhaustive details about the Bluetooth versions, check out the Bluetooth SIG's Specification Documents.
Your paired Bluetooth phone and headset/speakerphone don't need to be in direct line of sight to function properly and maintain their connection. Depending on your product's range, however, you can't roam too far. You can determine what a product's operating range is by looking at its classification. (This is applicable primarily to headset users; for speakerphones, range won't be as much of an issue since you'll have to keep your phone in your car.)
Bluetooth Class 2: On this kind of headset or speakerphone, you're limited to a working range of up to roughly 33 feet (10 meters). Most headsets and speakerphones today belong in this group.
Bluetooth Class 1: Headsets that meet this spec offer a range of up to 328 feet (100 meters). Models supporting this range are far less common. Only one headset we've seen, the Callpod Dragon V2, is categorized as Class 1.
Profiles for Mono Headsets
A Bluetooth profile is a spec that defines the standard capabilities of a Bluetooth-enabled device. For any Bluetooth headset you consider, look for the following two common profiles in the product's specifications list.
Headset Profile (HSP): You can talk on the phone through the headset, and you can do basic things such as accept incoming calls, hang up, and adjust the volume.
Hands-Free Profile (HFP): This profile enables you to talk on the phone and operate it. For example, you can redial the last number, handle call waiting, and dial by voice.
Profiles for Stereo Headphones
Most Stereo Bluetooth headphones also support the Hands-Free and Headset profiles, so you can make and receive phone calls with your Stereo Bluetooth headphones.
Advanced Audio Distribution Profile (A2DP): This Bluetooth profile enables your music source and the Bluetooth headset to stream music in stereo wirelessly.
Remote Control Profile (AVRCP): This profile enables your Bluetooth headset to control your music source wirelessly.
Profiles for Car Speakerphones
Car kits support the Headset and Hands-Free profiles. If your unit handles music, it will also support A2DP.
Object Push Profile (OPP): This profile enables sending data (or "objects"), such as virtual business cards or contact information. Car kits that support this profile can synchronize contact lists from the paired phone.
Phone Book Access Profile (PBAP): This allows the exchange of Phone Book Objects between devices. With a cell phone and a car kit talking nicely to each other, the speakerphone can display/announce the name of the person calling you.
Beyond Call Management
Bluetooth product makers continue to add features on top of the call-management capabilities you'd expect. These features have expanded recently to include handy voice prompts, text-to-speech tools, and information services.
Every time you switch on the Plantronics BackBeat 903+, for example, this stereo unit alerts you to the the time you have left for playing music and calls ("listen time remaining, 6 hours"). And products such as the BlueAnt S4 speakerphone and Q2 headset can announce your callers by name--provided that your phone supports automatic phone book transfer--and read your e-mail and text messages back to you.
Taking things to a whole new level, the Plantronics Savor M1100 is designed to work with the company's Vocalyst service. Free for 12 months with the purchase of the Savor M1100 (otherwise $3 per month or $25 per year), Vocalyst lets you listen to text messages, e-mail, and tweets. It also allows you to record messages and tweets as audio files. BlueAnt, Moshi, Plantronics, and other companies also integrate their products with the Bing 411 information service.