In cities like New York and San Francisco, AT&T admit that the heavy data usage has literally ripped it’s 3G network to shreds.
That’s for those that actually get 3G or even a slight signal, the US is covered with loads of countries and dotted with buildings which where actually making a call whatever phone you are using or on whatever network is a losing proposition.
That’s where femtocells come into it, little boxes which leech themselves off of home broadband connections in order to create little bubbles of cell phone service. AT&T call it a MicroCell, Sprint call it Airave and Verizon call it a Network extender. To read more go to pcmag.com