Call me if you can

I thought my needs were simple: mobile e-mail and voice communications from one device that works in every country on the planet. One phone, one SIM card, voice and data everywhere. It's not as easy as it sounds.

Turning to Wikipedia, I found that the Global System for Mobile Communications (GSM) is a second-generation (2G) technology used by over 2 billion people in more than 212 countries and territories. It has four major bands. GSM-900 and GSM-1800 are used in Europe, the Middle East, Africa and most of Asia. GSM-850 and GSM-1900 are used in the United States, Canada, and many other countries in the Americas. It's the system of choice for AT&T/Cingular.

Code division multiple access (CDMA) is a 2G technology used by over 350 million people worldwide, primarily in the U.S., Canada and Asia. It's the system of choice for Verizon.

Universal Mobile Telecommunications System (UMTS) is a 3G technology used by over 100 million people in 48 countries, primarily in Western Europe and Asia, including Japan, where NTT DoCoMo uses WCDMA, the most popular form of UMTS.

Once I mastered the alphabet soup, I set out to find a voice and data device that provided the coverage I needed. Of course, most devices are locked to a specific carrier, so you need to shop for a device/carrier combination. My experience in the U.S. is that CDMA/Verizon provides great call quality everywhere. GSM/AT&T may work in Paris and Stockholm, but try to complete a call in Boston.

Time to check out the phones. How about a cool new iPhone? It's a quad-band GSM phone (850, 900, 1800, 1900 MHz), and AT&T is the only carrier. Per my comments above, this means great service in Europe and China, and dropped calls throughout the U.S., and no Japan. Close.

How about BlackBerry? The 8830 sounded great - full CDMA coverage by Verizon in the U.S. on the high-quality CDMA200/EVDO networks, plus full roaming on the 900/1800-MHz GSM networks in Europe and most of Asia. Pretty cool. No Japan, however.

Other BlackBerries, such as the 8800, are quad-band GSM just like the iPhone, with the same coverage issues. The 8320 offers quad-band GSM plus WiFi roaming for data. Unfortunately, few carriers support voice calls over Wi-Fi at this point.

But wait! There's an obscure device from BlackBerry called the 8707G. It's quad-band GSM plus 2100-MHz UMTS, so it works everywhere. In addition, it’s not tied to any carrier. You can feel free to use AT&T, Vodaphone, O2 or whatever local carrier is inexpensive in the country you're traveling in. Because it is unlocked, no carrier wants to sell it to you. You have to buy it directly from RIM.

And then there's the Palm Treo 750, with quad-band GSM plus UMTS. It's a Windows Mobile device sold by AT&T that comes with a little stylus to navigate the Windows Mobile interface.

I purchased both a BlackBerry 8707G and a Palm Treo 750. Both worked in the U.S. before I left for Japan. Both worked the moment I landed in Tokyo. Both worked in my European travels. The winner - the BlackBerry using AT&T service via a single SIM card that roams anywhere on the planet. Just try doing 600 e-mails a day with a little stylus on a 2-by-2-in. Windows Mobile screen.

I've come to the end of my quest. After weeks of struggle and hours on Wikipedia, I have a single device that works for voice and data on every square inch of the planet. Makes you wonder why the device manufacturers and carriers make this so difficult.