AT&T has made improvements to its Edge network. iPhone carrier AT&T would not confirm that the work was being done to meet anticipated network demands of the Apple iPhone, which debuts in the US on 29 June.

"We continually enhance the capacity, coverage and overall performance of our network to ensure that our customers have the best experience possible," said AT&T Mobility spokesman John Kampfe.

Kampfe said that AT&T doesn't believe the iPhone's appearance on network links will bring the network crashing down. "We're confident in our network's ability to handle the traffic," he said. "After all, it already handles 62 million subscribers."

He would not, however, confirm or deny a report that cited an unnamed AT&T operations official and an internal AT&T report referring to a project called "Fine Edge" to beef up throughput, latency and coverage in preparation for iPhone's unveiling.

Reports suggest the operation has been under way for weeks and will finish 15 June. It describes upgrades to AT&T's data back end and tower configuration for allocating bandwidth to data and calls.

AT&T is adding more T1 lines in poorly performing towers to double the current EDGE performance of 40Kbit/sec. All the changes would affect all Edge handsets, not just iPhone, the report concludes.