Bluetooth—an open wireless protocol for exchanging data over short distances—seems like it was invented for mobile phones. Compared with the 3G and Wi-Fi radios in the Google phone, which are designed primarily for Internet access, Bluetooth has a short range. The theoretical range for Bluetooth 2.0 with Enhanced Data Rate (EDR) is about 33 feet (10 meters), but in practice, it's more like 10 to 20 feet.
Bluetooth has many uses, such as creating personal area networks (PANs) and sharing data between devices, but its primary application in mobile phones is wireless headsets. I cover the various applications of Bluetooth in the following sections.
Although they make us look like Borgs wandering around talking to ourselves, Bluetooth headsets have become part of the technology landscape. There's no denying the convenience of being able to talk to someone on a mobile phone completely hands-free; it expands the freedom that started with cordless phones at home. The difference, of course, is that instead of being able to wander around our houses yapping, now we can walk just about anywhere in the world yapping.
Setting up a Bluetooth headset in Android is simple. After you initially pair (link) your headset and your Google phone, the phone will remember the settings so that you don't have to repeat the pairing exercise each time you want to use your headset.
To get started, follow these steps:
Tap Settings > Wireless Controls to display the Wireless Controls screen, which includes Bluetooth and Bluetooth Settings options (Figure 4.17).
Figure 4.17 Wireless Controls allows you to toggle Wi-Fi, Bluetooth, and Airplane mode on and off.
You can tell at a glance whether Bluetooth is turned on; if it is, you'll see a check in its check box.
- If Bluetooth isn't turned on, tap the check box to enable it.
Tap the Bluetooth Settings option to open the Bluetooth Settings screen (Figure 4.18, on the next page).
Figure 4.18 Android's Bluetooth Settings screen.
The Bluetooth Devices section of this screen is where all the action happens. Here, you'll see any Bluetooth devices that are within range of your phone and discoverable. If your headset isn't listed, make sure that it's in discoverable mode (if you're not sure how to do this, consult your headset's user manual for instructions) and then tap Menu > Scan for Devices.
- When you see your headset in the Bluetooth Devices list (mine is called Jawbone in Figure 4.18), tap it.
If you're prompted for a personal identification number (PIN) for your headset (Figure 4.19), enter that code to gain access to your device.
Figure 4.19 Most Bluetooth devices require a PIN.
Consult your manual for your particular device's PIN, or search for it on Google.
When Bluetooth is on, you'll see an icon in the status bar. The left icon in the margin here indicates that Bluetooth is on; the right icon indicates that you're connected to a Bluetooth device.
Like the other three radios covered in this chapter, Bluetooth drains battery quickly when it's enabled, although not as quickly as GPS, Wi-Fi, and 3G do (in that order). It's important to practice good conservation techniques and use Bluetooth sparingly when you're away from power for long stretches of time.
Other Bluetooth profiles
Bluetooth isn't limited to wireless headsets—well, sort of. Bluetooth is all about profiles—wireless interface specifications for communication among Bluetooth devices. As I write this chapter, the T-Mobile G1 supports only the Hands-Free Profile (HFP) and doesn't support stereo Bluetooth, also known as A2DP (Advanced Audio Distribution Profile). This means that you can't stream music from your gPhone to a pair of wireless stereo headphones over Bluetooth. Neither can you connect to wireless keyboards or transfer files over Bluetooth. The only Bluetooth accessories that the G1 supports out of the box are wireless headsets and hands-free kits. As with all software from our favorite company in Mountain View, however, this situation is certain to change.
Currently, 28 Bluetooth profiles are available, each with a different application. Several other mobile phones on the market already support additional Bluetooth profiles (especially A2DP), and it's only a matter of time before the Google phone does as well.
Keep in mind that the G1 is the first Android phone released and certainly will get improvements down the road. Also, the Bluetooth implementation on your Google phone depends on the hardware manufacturer and the carrier. Some handset manufacturers (HTC, in the case of the G1) limit the phone's Bluetooth capabilities; others limit the Bluetooth options available. Check the Bluetooth specs on your particular gPhone by going to the carrier's Web site and drilling down into the specs for your specific phone.