CDMA vs. GSM: Which One Is For You?

Reader Scott Weidenhamer writes: I have read so much information on CDMA vs. GSM, also W-CDMA vs. EV-DO, and the more I read the more I can't make up my mind. I want the best technology, with the coolest features, but with great service behind it. (I live in northwest Ohio.) Is that too much to ask? What are your experinces with these technologies?

First, a primer. There are two major cell phone standards in the U.S. (not including the leftovers of the Nextel network, which had its own standard): CDMA and GSM. Verizon and Sprint use CDMA. Cingular and T-Mobile use GSM. So far, so good.

All carriers except T-Mobile now offer high-speed data services, also known as 3G. The high-speed CDMA network (from Verizon and Sprint) is called EV-DO. The high-speed GSM network (from Cingular) is called HSDPA. You might have gotten a little confused when hearing about W-CDMA networks, because a few other countries have W-CDMA networks, but U.S. services don't use this standard.

So, to recap:

Verizon & Sprint = CDMA (slow) and EV-DO (fast)
Cingular = GSM (slow) and HSDPA (fast)

Now to get to your real question: Which of these is best? Well, I've used all of these services extensively, and the first answer is that it depends on where you live. Start by checking out the various coverage locators. Here's Verizon's, and here's Cingular's. These maps aren't great, but they're a start. You can see that with Verizon, service is weak near the Michigan and Indiana borders, but Toledo and Lima are fully covered. Cingular has full coverage of that corner, with no service if you move a bit to the east. Depending on exactly where you live and where you frequently travel, this could determine your decision for you. (Another way to do this is to simply borrow a friend's phone and give the service a try for yourself. If it sounds good, it is good.)

Of course, high-speed access doesn't do you much good when you're just on the phone. Those fast 3G services I mentioned come into play when you're browsing the web, streaming music or video, or using the phone as a modem. These services are far more erratic than the slower voice services. I've had blazing speeds using an EV-DO modem in one hotel, while getting pokey throughput down the street. There's no way to really claim a "winner," though in my experience, HSDPA has much faster overall throughput, while EV-DO covers more of the country. If you travel a lot, you might want to go with EV-DO. If you only go to a few places and you know you can get an HSDPA signal there, I'd say stick with that technology.

I hope this has helped! With its zillions of acronyms, cellular technology is about as confusing as tech gets. Hang in there, and get a hands-on demo before you buy, if at all possible.

http://tech.yahoo.com/blog/null/1278