The G3 is LG's current flagship phone, but Sprint is pushing out an over-the-air update that shows some love to 2013's model, the G2, instead. This special delivery will bring in a number of general enhancements that some users may be happy to see. HD Voice is seeing improvements, and there are some LTE-related changes as well. These are joined by a security patch fixing something that's unspecified in the change log.
Verizon pre-announced its VoLTE service a few weeks ago, but now it's rolling out. Customers can finally start taking advantage of VoLTE calling starting today—that assumes people still make phone calls, which is debatable. You need to have a supported device of course, and there are still a few caveats.
AT&T has announced that the Galaxy S4 Mini, yes - the phone that came out back in November, is coming to the carrier May 23rd with HD Voice. It will be the first device on the network with support for making VoLTE (voice over LTE) calls. The handset isn't available for pre-order, but the carrier does have it listed as "coming soon."
AT&T is the first carrier to support making voice calls over LTE, supporting simultaneous voice and data over the IP network.