According to the latest news on the Web, AT&T is performing upgrades to its network and is making use of the 850MHz spectrum so as to enhance the 3G network to alleviate dropped calls and poor connectivity for iPhone 3G and iPhone 3G S customers. “The 850, when it's turned on in individual markets, people notice a big difference,” AT&T spokesman Mark Siegel seems to have stated, as reported by Gearlog on Tuesday.

As many of you might already know, Apple recently announced that it managed to sell more than one million iPhone 3GS units during the first three days of availability, yet there are no details on how many of the devices were activated on AT&T's network. Even so, it is a common fact that iPhone users are employing the carrier's network more intensively than others, and additional handsets activated will probably slow down the network.

It seems that AT&T already thought about leveraging its network to handle more strain, and it will offer 3G services on the 850MHz spectrum. Up until now, the mobile phone carrier has been using mostly spectrum in the 1900MHz band for the 3G services, yet it seems that the spectrum has become saturated. As the operator sells more 3G devices, users will have to be crowded in the same spectrum band if another solution does not surface.

For what it's worth, users have already reported problems with the connectivity, including dropped calls and slow Internet speeds while using the iPhone 3G, and it seems that the problem was acute in some of the country's large cities, like New York and San Francisco, where the company uses mostly the 1900MHz spectrum.

The use of the 850MHz spectrum for 3G services should allow AT&T to fix some of the issues with the crowded network. In addition, it seems that the carrier is also improving the network in other ways, including the addition of more cell sites on the 2100MHz frequency, which offers faster speeds on shorter distances. In comparison, 850MHz works at longer distances and can penetrate walls much easier.