In its attempts to quickly build up its 3G voice and data network, AT&T is knowingly reducing the signal strength of its existing 2G network used by the first-generation iPhone, Motorola's BlackBerry and RAZR and other handsets, according to a Friday Open for Business report. AT&T is said to have shifted some of its transmitters from the 850MHz 2G band to the 1,900MHz band in certain areas. AT&T subscribers and owners of 2G cellphones are finding weaker signal reception in areas that previously had strong reception, with the only fix available while remaining with AT&T being to upgrade their hardware to 3G devices.

AT&T continues to sell handsets equipped with 2G radios exclusively, with about half of all its devices relying on the older network. The signal issues have become apparent over the course of the last few months, and when the issues have been brought up to AT&T representatives, a one-time credit of $200 is offered if the user agrees to upgrade to a new handset.

The provider, along with Apple, has been named in a class-action lawsuit late last year over performance claims for the iPhone 3G on the high-speed data network due to the sheer number of devices saturating the market. For this reason, AT&T has been aggressively upgrading its 3G infrastructure.