Overall Findings
EDGE is a faster version of GSM, and TDMA is effectively obsolete. Therefore, TDMA is not a viable choice anymore. It effectively comes down to GSM and CDMA, with GSM beating out CDMA for user- and consumer-friendliness.
Speed: EDGE Has the Advantage
EDGE is three times faster than GSM and is built upon that standard. It is designed to accommodate streaming media on mobile devices. AT&T and T-Mobile have EDGE networks.
User-Friendliness: GSM Is Easiest to Transfer
CDMA phones may or may not have SIM cards. User information is stored with the service provider, which must give its permission to switch phones. CDMA phones must be programmed with every carrier you use. When you switch carriers, the phone must be reprogrammed for that carrier, even if it’s an unlocked phone.
Providers: Look for Your Favorites
GSM is the most popular cellular technology in the U.S., and it is bigger in other countries. China, Russia, and India have more GSM phone users than the U.S. It’s common for GSM networks to have roaming arrangements with foreign countries, which means GSM phones are good choices for overseas travelers. EDGE is an evolution of GSM, so it has the same availability as that older standard. CDMA competes with GSM. Sprint, Virgin Mobile, and Verizon Wireless use the CDMA technology standard in the U.S, as do other smaller cellular providers. Since 2015, all U.S. carriers are required to unlock customer’s phones after they fulfill their contracts. Even if you unlock your phone or to buy a new unlocked phone, it is either a GSM or CDMA phone, and you can only use it with compatible service providers. However, having an unlocked phone gives you a wider range of service providers to choose from. You aren’t limited to only one. TDMA, which predates the more advanced GSM technology standard, has been incorporated into GSM. TDMA, which was a 2G system, is no longer in use by the major U.S. cellphone service carriers.
Final Verdict
The quality of the phone service has nothing to do with the technology the provider uses. Quality depends on the network and how the provider structures it. There are both good and not-so-good networks with GSM and CDMA technology. You are more likely to run into quality concerns with smaller networks than with the big ones.
