pmichaud.com - Pm - CellularInternet

Last fall I decided to take an extended road trip, and in preparation for that trip I decided it would be a good idea to get a mobile phone. Many of my friends and colleagues were shocked, because I hadn't owned a mobile phone in over a decade.

Of course, this started the grand search for a mobile phone service provider, and the phone itself. I knew that on the road I would want access to electronic mail and the Internet, and Wi-Fi hotspots are not always easy to find--cellular and GPRS still have quite a bit more coverage options. Also, there have been many times where I've wanted to demonstrate something on the web but didn't have an available phone line or Internet connection with which to do it.

I finally settled on T-Mobile's Internet Unlimited Plan, which provides unlimited data transfer and data minutes for a flat $19.95/month over the cost of a T-Mobile voice plan. For the phone itself, I chose the Sony Ericsson T610 phone for its compact size and color display. As many people will tell you, I'm a real believer in small packages--my notebook computer is a Dell Latitude X300 which is only 3/4" thick and weighs under 3lbs.

Once I got everything working (details below), the package is really sweet. The T610 comes with Bluetooth capabilities, so all I have to do to connect from my notebook to the Internet is turn on my phone's Bluetooth option (I normally leave it off to conserve power), start a special dialup connection on my notebook, and I'm on the Internet. The connection speed is a bit slow--about the same as a good 33.6K dialup connection--but definitely adequate for checking email and viewing a few web pages. And coverage is excellent--it basically works anywhere that I have T-Mobile service. It's really nice to be able to pop open the notebook in a restaurant, meeting, park, etc., and grab some information of the Internet or jot down an entry to a wiki page. Even nicer is that the entire package--notebook computer, power, phone, and Bluetooth dongle--fits into a small leather portfolio case I often carry with me.

I found the most frustrating part of the setup to be in getting a Bluetooth connection between the computer and phone to function properly. The T610 phone can also communicate with the notebook using an infrared port, and it works great, but there's something very "geeky cool" about having it happen via RF. Also, when using the infrared link passers-by have a nasty tendency of picking up the T610 and saying "Wow, what a cool phone" as they unknowingly break my Internet connection. So, Bluetooth is a nicer option for me.

First, I had to get Bluetooth capabilities into my notebook. Dell sells a Bluetooth option for the X300 notebook, but it has to be installed at the time of purchase and when I bought the notebook I figured I didn't need it, or that I could upgrade later. Silly me--I did need it, and the internal Bluetooth capabilities aren't available as an upgrade. So, I purchased an Ambicom Bluetooth USB device from CompUSA and had lots of problems with getting the drivers to work--they tended to freeze up under Windows XP. I finally got fed up dealing with the Ambicom, bought a D-Link DBT-120 and have had no problems since.

So, the overall steps for getting my cellular internet connection were (not counting any of the missteps):

Sign up for T-Mobile's Internet Unlimited Plan
Purchase the T610 phone
Configure the T610 for a data connection
Enable Bluetooth capabilities between the notebook and the phone
Set up the computer for dialup connection through the phone

Finding the information for setting up the phone was another challenge, but a few Google searches came through for me there. On the T610 I had to do the following:

Main Menu => Connectivity => Data Comm => Data Accounts => New Account
Select "GPRS Data" for the account type
Give the new account a name (I chose "T-Internet")
Set the APN to "internet2.voicestream.com", which is apparently the gateway host for T-Mobile's internet service
Leave the Username and Password fields blank
Select "Save" to save the account

Once the data account has been set up, we then need to know the account's "CID". On the T610 you can find the CID by selecting the account from the "Data Accounts" menu. On my phone, my new connection ended up being "CID=2" (with CID=1 being used for T-Mobile's t-zones service).

From this point it's simply a matter of configuring the connection between the notebook and the phone and setting up the dialup networking. Although I knew I wanted to use Bluetooth, I started with the infrared connection first to reduce the number of variables. I turned on the T610's infrared port, pointed it at the infrared port on the notebook, and Windows XP automatically detected and installed the infrared modem hardware. From there I simply created a new dialup connection that dials the number "*99***2#". This is a special number "*99***" used by the phone to create a data connection using the account identified by the "2" (CID=2 from above). No username/password is needed--just dial and everything gets connected just like a normal dialup modem connection would.

Even though this is set up as a "dialup connection", it's not really making a standard "voice call"--i.e., it doesn't use any of my mobile plan's airtime minutes. It's a "GPRS data connection", which remains completely digital, and I can still receive voice calls on the phone while I'm on the network. Of course, it's difficult to talk on the phone if I'm connected via the infrared port.

After getting the infrared port to work, the next challenge was to get Bluetooth to work. Bluetooth setup was far easier with the D-Link than than Ambicom--for one, the Ambicom seems to work properly only if it was plugged in from a cold restart. It got pretty annoying to have to power off the computer and go through a reboot sequence just to plug in a simple USB device. The D-Link doesn't appear to have such limitations.

From the D-Link's "Bluetooth neighborhood", I simply do a search for Bluetooth devices, which finds the T610, double click on the T610 icon to see its available services, and then double-click on the "Dialup Networking" service. The Bluetooth software then goes through a process of "peering" the notebook with the T610. I don't completely understand the peering process yet (because I've had trouble getting it to work reliably with the Ambicom and under Linux), but it basically involves using a PIN code to authenticate the notebook and the phone with each other. Once the devices are peered, I set up a dialup connection to "*99***2#" as before and I'm connected.

Overall, I'm quite pleased with the setup and service, and it's come in quite handy many times. In January I gave a presentation on WikiWikiWebs at the North Texas Linux Users Group meeting and it was really nice to be able to connect to the Internet for the demonstration. While on the road last fall it was very convenient to be able to pull off to the side of a road to download a map/directions to a destination or search for nearby restaurants and Wi-Fi hotspots.

Questions and comments about this article can be sent to pmichaud@pobox.com. Coming soon: CellularInternetForLinux!