Spring is finally here and 2013 is the first year that all four major U.S. wireless carriers have 4G LTE networks in commercial operation. Many of you will know the basics of the 4G landscape: AT&T Inc. slightly edges Verizon Wireless on average speeds but Big Red has more than double the LTE footprint of Ma Bell. Sprint Nextel Inc. is lagging the big two in speeds and footprint and T-Mobile USA is just getting started with its deployment. Given these basic facts, the big question is: What can Sprint, T-Mobile and the regional carriers do to compete on LTE? The key word for both Sprint and T-Mobile in 2013 will be "unlimited." Just for smartphones, mind, not tablets or laptops. AT&T and Verizon will continue to push cheap US$10 jump-on costs for tablets on their shared plans (even if you end up blasting through the data cap with a tablet). What will be interesting to me is the services that Sprint and T-Mobile could add to the mix. T-Mobile's merger with MetroPCS should let it consider deploying video chat over LTE devices across its network. Whatever happens, it seems most likely that T-Mobile and Sprint will be competing for the same pool of value-hunting customers that want good-enough LTE speeds. Here's where we stand right now with LTE deployments in the US: I used data from RootMetrics and the operators themselves to compile the table. Please let me know if you have any new data. — Dan Jones, Site Editor, Light Reading Mobile