These two abbreviations stand for 'time-division duplexing' and 'frequency-division duplexing'.
The good news is you can make phones that are compatible with both standards, as Samsung has just proved. But similar to America's different, incompatible GSM and CDMA phone systems, there are two different standards for LTE - TDD and FDD. LTE is the formal name for 4G, meaning Long Term Evolution.
The Galaxy S4 and S4 Mini are getting 'TDD/FDD Dual Mode LTE' versions, the company has announced. Samsung's not one to shy away from releasing zillions of different versions of essentially the same phone, but its two latest models are intriguing in one specific way.
