Bluetooth Everywhere

Hi all,

Please allow me make a short comment/rant on the importance of DUN for mobile and wireless developers. Last week, I talked about what DUN is, and how it fits with the other Bluetooth Profiles. However, I failed to explain the importance of this profile. Let me put it succinctly:

If you want to your laptop to access the internet, the you need THIS profile enabled on your mobile phone and your laptop.

Yes, I do realize that DUN *could* be used by desktop computers to access the internet as well, but desktop computers are stationary devices, and WiFi is better suited for that task since power consumption is not a issue.

Yes, I also realize that PDAs *could* use DUN to connect to the internet, but nobody makes PDAs anymore. In fact, now that Microsoft has renamed Windows Mobile to Windows Phone, then that’s a good indicator that the PDA market is dead.

Please note however, that if you have a data plan on your mobile phone, your network carrier does NOT want you to connect your laptop to the internet over DUN. This concept is called “tethering”, and the carriers have decided to make DUN a complicated and pricey issue. Therefore, if you want to use DUN, you will most likely need to:

1. contact your network carrier
2. tell them that you want to tether over Bluetooth
3. wait for them to scream and faint
4. They will then tell you how much EXTRA you need to pay in order to tether (whether you use Bluetooth or not)
5. They will also tell you the username and passcode to enter in order to access the network over DUN

That doesn’t sound fair, does it? If you had a normal smartphone application on your phone, it doesn’t need to know a passcode to access the network. However, it you want to tether your laptop, then you do need to enter a  passcode on your laptop in order to access the internet.

I’m very tempted to write a hack that allow users to bypass all that nonsense. I’ll be sure to let you know if I make up my mind.

Alright, let’s continue to learn about the various intricacies of the Bluetooth specification by looking at another of one of the more common Bluetooth profiles: DUN.

Profile Name: Dial-up Networking Profile

Abbreviation: DUN

UUID:  0×1103

Description: The Dial-up Networking Profile (DUN) is a profile that largely depends on the functionality of the Serial Port Profile (SPP) in order to operate, as you can see from the image above. This profile is modeled after the connection mechanism that was widely used in the 1990’s for home computers to get access to the internet: the dial-up modem. Please note that even though dial-up modems are not available today, this profile is still widely used by laptops and other mobile devices to access the internet through a Bluetooth-enabled mobile phone.

Common Implementations: laptop computers, desktop computers, mobile phones