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Mobile

The 411: Tethering

Every two weeks, CNET editor Nicole Lee answers your questions about cell phones and cell phone accessories in The 411.

Welcome to the 411, my column answering all your questions about cell phones and cell phone accessories. I receive plenty of questions about these subjects via e-mail, so I figured many of you might have the same questions, too. At times, I might solicit answers from readers if I'm stumped. Send your questions and comments to me at nicole.lee@cnet.com. If you prefer to remain anonymous, let me know in the e-mail.

Question: I've heard about AT&T possibly allowing tethering for the iPhone in the future, and I was wondering if you could tell me what tethering actually is, and what's so great about it, especially since you can use Wi-Fi.--Bill, via e-mail.

Answer: Wi-Fi hot spots are more ubiquitous than ever before, but you still can't always get Wi-Fi everywhere, especially if you don't happen to live in a major metropolitan city. Even if you do, not all of them are open and free to use. An easy alternative is to use tethering, which is a way for you to use your cell phone to provide Internet access to another device, essentially using it as a modem. This is done either via Bluetooth or a USB cable.

Tethering in and of itself is a pretty old technology. I remember around nine or so years ago, I was able to use my Sony Ericsson T68i as a rather slow Bluetooth modem with my PowerBook G4, and that was without purchasing a special mobile broadband plan. These days, most carriers do require you to purchase an additional mobile broadband or tethering data plan, which may cost around $60 a month.

USB tethering is as simple as plugging in a USB cable from your cell phone to your laptop. However, not all computers have the appropriate software or drivers for that kind of connection. With Bluetooth, it's a little easier.

As long as your phone has the Dial-Up Networking (DUN) Bluetooth profile, it is theoretically possible to tether your phone to your laptop. The process differs from computer to computer, but here are the basic steps to get your phone to act as a Bluetooth modem.

First you have to pair your phone to your computer. You can often go through a Bluetooth pairing wizard on your computer that will help walk you through the process. For Mac OS X, be sure to check a box that says "Access the Internet with this phone's data connection" as the phone is paired; the next screen will prompt you for dial-up details. For Windows PCs, you then have to head over to the Network Connections area and then set up a new connection or network. You're essentially using your phone as a dial-up modem, so be sure to select Dial-up as the connection.

As for the number to enter, that differs from carrier to carrier. Sprint uses the phone number #777, while AT&T is either *99# or *99***3#, depending on your phone. For Sprint and Verizon, you can leave your username and password fields empty, whereas for AT&T and T-Mobile, you might have to enter a username/password combination. For AT&T, you can try WAP@CINGULARGPS.COM for the username and cingular1 for the password. Try asking your provider for more specifics if these steps don't work. Some carriers also provide their own dial-up applications so you don't have to go through this configuration process.

But, like you said, there are some phones that don't allow for tethering, like the Apple iPhone for AT&T. As far as we know, this is unique to the U.S. Other countries do allow the iPhone 3GS to have tethering. If you're willing to jailbreak your iPhone, you can do the same thing with AT&T, and there are rumors that the fourth iteration of the iPhone might allow it, too. Still, we wouldn't hold our breath.