Networking / Beginners

Understanding Pairing and Discovery

A key concept to understand when you're dealing with a Bluetooth device (like a cell phone or cordless headset) is pairing. Pairing is simply the process of two Bluetooth-enabled devices exchanging an electronic handshake (an electronic "greeting" where they introduce themselves and their capabilities) and then "deciding," based on their capabilities and your preferences (which you set up within the Bluetooth preferences menu on your device), how to communicate.

A typical Bluetooth cell phone has three key settings you need to configure to pair with another Bluetooth device:

  • Power: First, you need to make sure that Bluetooth is turned on. Many phones (and other battery-powered devices) have Bluetooth turned off by default, just to lower power consumption and maximize battery life. On your phone's Bluetooth menu, make sure that you have turned on the power.
  • Discoverable: With most Bluetooth devices (such as cell phones or PCs and Macs), you can configure your Bluetooth system to be discoverable, which means that the device openly identifies itself to other nearby Bluetooth devices for possible pairings. If you set your device to be discoverable, it can be found - if you turn off this feature, your phone can still make Bluetooth connections, but only to devices with which it has previously paired.
    TipThis setting has different names on different phones. On Pat's Motorola phone, it's Find Me; yours may be different.
    Remember Some phones and other devices aren't discoverable all the time. For example, Pat's RAZR phone becomes discoverable for 60 seconds when you select Find Me.
  • Device name: Most devices have a generic (and somewhat descriptive) name identifying them (like Motorola V3 RAZR). You can modify this name to whatever you want ("Pat's phone," for example) so that you recognize it when you establish a pairing.

One other important Bluetooth concept affects the ability of two Bluetooth devices to talk to each other: Bluetooth profiles. A profile is simply a standardized service, or function, of Bluetooth. There are more than two dozen profiles for Bluetooth devices, such as HFP (Hands Free Profile) for hands-free cell phone use, or FTP (File Transfer Profile) for sending files (like pictures or electronic business cards) from one device to another.

Remember For two devices to communicate using Bluetooth, they both must support a common profile (or profiles). And, for two Bluetooth devices to not only communicate but also do whatever it is that you want to do (such as send a picture from your camera to your Mac), they both need to support the profile that supports that function (in this case, the FTP profile).

Making all this happen is, we're sorry to tell you, highly dependent on the particular Bluetooth devices you're using. And because more than a thousand Bluetooth devices are available, we can't account for every possibility here. This is one of those times where you should spend a few minutes reading the manual (sorry!) and figuring out exactly which steps your device requires. (We hate having to tell you that, but it's true.)

We don't totally leave you hanging here though. Here are some generic steps you need to take:

  1. Go to the Bluetooth setup or configuration menu of both devices and do the following:
    1. Turn on the Bluetooth power.
    2. (Optional) Customize your device name to something you recognize.
    3. Make the devices discoverable.
      Typically, you set up one device to be discoverable and the other to "look" for discoverable devices. For example, you may press a button on a Bluetooth cordless headset to make it discoverable, and invoke a menu setting on your phone to allow it to discover compatible Bluetooth devices.
    One device notifies you with an alert or onscreen menu item that it has discovered the other, and asks whether you want to pair. For example, if you press the button on your headset, your cell phone displays a message asking whether you want to pair.
  2. Confirm that you do indeed want to make your device discoverable by pressing Yes or OK (or whatever positive option your device offers).
  3. Enter the passkey and press Yes or OK.
    Most Bluetooth devices use a passkey (numeric or alphanumeric code), which allows you to confirm that it's your device that's pairing and not the device belonging to the guy in the trench coat who's hiding behind a newspaper across the coffee shop. You find the passkey for most devices in their manuals (drat! - the dreaded manual pops up again). In some cases (like pairing with a PC or Mac), one device generates and displays a passkey, which you then enter into the other device.
    Your devices verify the passkey and pair. That's all you have to do in most cases - you now have a nice wireless Bluetooth connection set up, and you're ready to do whatever it is you want to do with Bluetooth (like talk on your phone hands free!).

Tip After you've paired two devices, they should be paired for good. The next time you want to connect them, you should only have to go through Steps 1 and 2 (maybe even just Step 1) and skip the whole passkey thing. Bluetooth devices are supposed to mate for life (like penguins). Sometimes, however, Bluetooth is a bit funky and things don't work as you had planned. Don't be surprised if you have to repeat all these steps the next time you want to connect. A great deal of work is going on to make Bluetooth more user friendly, and making pairing easier and more consistent is the primary focus.

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