This term, increasingly in use in the wireless world, refers to the next—and fourth generation—stage in the evolution of networks for mobile devices.
4G technology promises to increase the rates at which phones and other portable devices can access the Internet and data services. The increase will be dramatic, to a rate as high as 70 to 100 megabits per second, or up to a hundred times faster than today’s high-speed, 3G networks allow. Though interference and other factors will limit how often those maximum speeds are achieved, 4G networks should alleviate network congestion and allow for music and video to be streamed and downloaded more quickly to phones and other mobile devices.
Quality levels could also be higher for that content—for example, video will likely be in high-definition mode, which is too data-heavy for today’s mobile networks to support. And 4G will also facilitate the uploading of content, such as high-def videos, from devices to the network and the Internet.
Alas, you likely won't enjoy 4G in any meaningful way for several years. That's because both of the two competing 4G technologies, WiMax and Long-Term Evolution (LTE), are only in the trial stage. WiMax proponent Sprint and its recently acquired partner Clearwire have been testing WiMax in several U.S. cities since 2008, but no rollout of the technology has yet been scheduled. LTE backer Verizon is pushing to launch its 4G network in 2010, but only in select areas. It's been reported that a 4G-enabled device from Apple is one reason for Verizon's aggressive timetable. Besides Verizon, LTE enjoys the support of AT&T and T-Mobile.
The faster a network is, as a rule, the more power demands it makes on devices that connect to it. (Case in point: iPhones that run on the slower 2G network have better battery life than when they run on 3G network.) Until there are significant improvements in battery technology and the energy efficiency of phones, 4G-compatible phones would likely either have unacceptably short run times or have to grow to an unacceptable size to accommodate a bigger battery. —Mike Gikas