To accommodate explosive growth in demand for wireless data, many mobile carriers have begun touting next-generation “4G” networks. But to consistently achieve fast speeds, especially indoors in densely populated areas, some carriers are starting to offer small, low-power indoor cellular access points called “femtocells.”
The original draft of this story included a discussion of Cooper’s Law, Shannon’s limit and the fact that 3/4 of a circle’s area lies outside an area delimited by half its radius. All of which explain why AT&T isn’t crazy to ask you to pay an extra $150 to make your smartphone’s 3G radio achieve data throughput better than a local WiFi network. But that was a bit much for a piece of this scale.