Sprint and Verizon have recently launched brand-new 4G networks, which use a completely different technology from their existing 3G networks. T-Mobile and AT&T have continued to invest in improving their existing networks, and T-Mobile has labeled its improved network "4G." AT&T is set to deploy its new 4G network next year.
4G technology tends use wireless frequencies more efficiently than 3G, meaning networks can cram more data into a signal than they had been able to in the past. But that's only one part of the solution.
"4G on its own is not going to solve the problem," said Ashkay Sharma, analyst at Gartner. "Networks have to adopt a more holistic solution."