AT&T during the call to discuss its spring results revealed that its San Francisco upgrades lag about 90 days behind those in New York City. It didn't say when it expected upgrades to be completed, although Apple chief Steve Jobs alluded to the situation improving by the end of the summer. Among the upgrades are the addition of cell sites, third or fourth carriers and better antennas on existing sites and fiber optic to handle the backhaul supporting the network.
