Poor iPhone data coverage in big cities has been one of the major gripes against the iPhone and specifically against its sole US carrier, AT&T. According to AT&T spokesman, Mark Siegel (via Gearlog), they’re doing three major things to improve their coverage and speeds, some of which will have a huge positive effect on coverage in cities like New York, San Francisco and Los Angeles.
"3G on 850 Mhz."
AT&T is rolling out the 3G on 850 MHz over the next few months and, according to Siegel, "The 850, when it’s turned on in individual markets, people notice a big difference."
850Mhz connections are better at penetrating buildings but can’t travel as far as 1900MHz.
AT&T already announced its other two initiatives which are improving the line speed to the cell towers by installing fiber and also upgrading the networks to the double speed 7.2 Mbs HSDPA+ equipment. AT&T has a private 7.2Mbs network running in Chicago that isn’t yet visible by their customers.