The two most widely used networks in the world are Global System for Mobile Communications network and Code Division Multiple Access. Most cellphones are designed to work exclusively with one network or the other. Most countries outside of the United States use GSM. Verison uses CDMA. While CDMA networks exist abroad, they’re present in fewer locations than GSM. Thus, Verizon 4G phones won’t work literally all over the world, but they will work in certain countries.
While Verizon offers some global phones designed to work with both GSM and CDMA networks, none of these are part of the company’s 4G lineup as of July 2011. Verizon offers three 4G phones. These are the LG Revolution, the HTC Thunderbolt and the Samsung Droid Charge. All of these are CDMA only and won’t work on any GSM network regardless of location.