When AT&T rolls out its LTE service, its handsets will be slimmer and have better battery life than their Verizon Wireless counterparts, says AT&T CEO Ralph de la Vega.

According to de la Vega, AT&T's secret sauce is circuit-switched fallback. CSFB lets a 4G handset use LTE for data and legacy 3G networks for voice. This backwards compatibility forces each LTE handset to have two radios, but AT&T claims its implementation will not add a lot of bulk to the handset or excessively drain the battery.


CSFB improves battery life by allowing the handset to keep its 3G radio dormant until an incoming call is received or an outgoing call is placed. The phone doesn't have to fully power two cellular radios all the time, so its battery life is extended.

This Is My Next asked Verizon about CSFB and the carrier would neither confirm nor deny whether it uses this technology in its LTE handsets. Whether Verizon uses CSFB or not may not really matter. By the time AT&T gets its LTE handsets out the door, Verizon will be moving its voice services off 3G and onto LTE, a process that'll begin in 2012. [CNET via This Is My Next]