iPhone owners in the New York City and San Francisco Bay areas are starting to see much needed improvements in the quality of AT&T's 3G network, according to reports received by Electronista and others. Carrier spokesman Seth Bloom recently indicated that parts of New York City have received 3G over the 850MHz frequency on their network and that some users are noticing a much more reliable signal than they have before. Which areas have been upgraded haven't been detailed, nor has the timetable for remaining updates.

A separate anecdote from TechCrunch also notes that service in the South of Market area of San Francisco also appears to be much better than it has in the past. The wider Bay Area, and particularly downtown San Francisco, has been infamous for poor and often completely non-functional 3G due to a network oversaturated with iPhone 3G and 3GS units. However, it now seems to be at least mostly functional in at least small regions of the main city.

"People started telling me they were noticing the same thing," the site's MG Siegler writes. "It would go in and out at certain times, but for the most part, AT&T’s network actually seemed to be working in the area."

The provider has been filling out the gaps in 850MHz coverage since at least late spring, with updates in major but less noticeably bogged-down cities such as Atlanta, Las Vegas and San Diego. Many of the areas suffering from severe slowdowns have been relying on 3G over the 1,900MHz band, which has considerably less available bandwidth than 850MHz data, a shorter range that requires more towers, and weaker penetration indoors. In Canada, where 850MHz 3G is much more widespread on Rogers' service, such slowdowns are rare.

On a larger scale, the 850MHz upgrade is expected to finish in the next few months and should be matched by the long-promised 7.2Mbps HSPA update as well as upgrades to the backbone to ensure that 850MHz access isn't hamstrung by the underlying infrastructure.