AT&T Inc. plans to buy wireless spectrum from Qualcomm Inc. for $1.93 billion and boost its 4G network, aiming to counter criticism over iPhone service quality and a threat from rivals such as Verizon Wireless.

AT&T is the sole U.S. carrier for Apple Inc.’s iPhone, but smaller rivals including  Sprint Nextel and Clearwire Corp. have been adopting 4G, a new wireless standard that enables better Internet access including video. Get the full story »