I’m Cellular

Q: Want to make free calls, virtually anywhere?
    
Solution: Use your @Home cell phone and connect via W-Fi … 

You can make unlimited, free calls not only @Home, but also at any place that you have Internet access via Wi-Fi, like coffee shops. With a little help, you can expand that to any place where you have Internet access, such as your hotel room. This could save you a bundle in roaming charges if you are traveling internationally, as you will be able to call (and access the Internet) for free.

For @Home subscribers, T-Mobile does not distinguish between your usage on your home Wi-Fi network or on other Wi-Fi networks, so hopping onto a Wi-Fi network is a great way to save money. Calls are billed the same from any hotpot just as if you were at your @Home hotspot. So calls to/from the U.S. are free (as you said), and calls to foreign locations incur only Long Distance charges (instead of more costly roaming charges). 

Solution 1: Connect to the existing hotspot (from your Wi-Fi capable, @Home phone).
How: If the Wi-Fi hotspot already exists, you can connect to the hotspot and use it. This works whether the hotspot is open (no password) or requires a password. Just go the menu of your Wi-Fi capable phone and scan for networks, select the local network, and enter the password (if any). Done! Thereafter, all calls are free and your calls will be handed off to the cellular network if you leave the hotspot coverage. Calls that are originated on the hotspot are free, even if they end up being handed off to the cellular network (read in a previous, thorough @Home review).

When you are connected to the Wi-Fi network, you will see the words “UMA” in the handset display (where you’d usually see the serving, cellular network name). You must be connected to the Wi-Fi network to get free calls, so be sure to look for this indication. 

Solution 2: Create your own Wi-Fi hotspot for your @Home phone to use. 
How: If there is no Wi-Fi network but you do have access to an Internet connection, you can create your own hotspot for your phone to use. Just plug in a small, wireless router (like the minuscule, Apple’s AirPort Expressthat is about the size of a deck of playing cards). Apple’s portable, wireless router is made for this: it plugs into the wall, and you connect it to the Internet connection using a standard Ethernet cable (RJ-45). Then, just connect to the new network from your @Home handset (“Set Up Wi-Fi” on my BlackBerry 8320 Curve) and you’re in service!

Plug it in, and Connect to Ethernet

To make it completely simple to use when you are travelling, I configure the device and then toss it into my luggage. Although this device is extremely portable, I’ve not been impressed with the ability to set it up with a Windows OS (which I use on business travel), so it can be inconvenient to try to change settings while on the go. I configure my AirPort Express with a secure password for the Wi-Fi network that I will create.

There’s a nice, simple explanation of the use and setup of AirPort Express here, which includes the added benefits of acting as a wireless extension cord for your (a) printer, (b) stereo, (c) Ethernet connection, including extending the range of an existing Apple Wi-Fi network. For more on extending the range of your home Wi-Fi network, please see my notes here.

Wi-Fi Hotspot

You’re Secure: You are not at risk when using a public hotspot for these calls. There are multiple levels of security, even if you are using a public hotspot. Your @Home phone still uses embedded GSM security (the A3 & A5 algorithms), since UMA takes the whole GSM stack, packetizes it and sends it over the Wi-Fi (IP packet) network and the internet. While connected, your connection is also encrypted from the device to the T-Mobile network by encapsulation in an IPSec VPN tunnel. Genius!

Summary: Free calls at home is a great deal, but even better is free calls on the road (wherever you have an Internet connection), especially internationally.