Sprint would have to pay more than $1 billion if its plan was rejected, The Wall Street Journal reported.
Details of an agreement to merge T-Mobile with SoftBank's Sprint aren't yet available.
The update fixes a bug that wouldn't allow GS5 owners to receive SMS or MMS messages.
Carrying voice calls over LTE means faster call setup, the carrier said. And it beats AT&T's own announcement, too.
With the FCC giving AT&T's Leap acquisition the thumbs up two months ago, AT&T is targeting Sprint and T-Mobile with its no-contract, low-cost provider.
The carrier added 1.3 million subscribers in the first quarter, proving that wireless customers aren't the only people gaining in the ongoing price war among wireless providers.
The carrier continues to wage war against its rivals with a petition to eliminate overage penalties across the board.
Of the big four U.S. carriers, only T-Mobile will let you use Samsung's new feature.
Subscribers can now snag an LTE-enabled tablet for the same price as the Wi-Fi-only model.
The $40 plan will offer unlimited data, but only 500MB of LTE.