There are two flavors of 4G LTE: FDD (frequency division duplex) and TDD (time division duplex). Without getting too technical, let’s just say that the former makes a lot more sense for operators who are already running a GSM network, whereas the latter isn’t expected to gain any widespread adoption outside China. Now Sprint entered the 4G race a year or two before everyone else by launching a WiMAX network, thinking that the industry would rally around that particular standard. The support never came, and Sprint was forced to announce that they’d have to switch to LTE to remain competitive. The thing is though, when Sprint built their WiMAX network they did it by creating a separate company called Clearwire. Why? So other companies could invest in said network. Clearwire is going to transition to 4G LTE using the TDD flavor, the one that’s China only for now. They can’t do FDD because they don’t have the right kind of spectrum. Sprint on the other hand is going to launch their own FDD 4G LTE network by reusing some of their PCS spectrum, which today is being used to run their CDMA network.
All of these complicated abbreviations aside, something important just happened on the other side of the world. The Chinese government announced that they’re not going to issue any 4G LTE licenses for another two to three years. This is significant because China is a huge market that infrastructure vendors and handset makers want to play in; translation: no one will give a shit about TDD 4G LTE for the next three years, which puts Clearwire in the exact same situation they were in back when they were using WiMAX.
It’s not all doom and gloom however. Qualcomm’s Snapdragon S4, which will be at the heart of a majority of Android smarpthones coming out over the next 12 to 24 months, supports both FDD LTE and TDD LTE, though we don’t know how much extra a device that complicated would cost.