AT&T has expanded 4G voice-over-LTE (VoLTE) services to parts of South Carolina and is promising more markets and interoperability work in 2015.
"AT&T has rolled-out VoLTE and HD Voice in select areas in the District of Columbia, Georgia, Illinois, Indiana, Maryland, Michigan, Minnesota, Nevada, North Carolina, Ohio, Oregon, Pennsylvania, South Carolina, Tennessee, Texas, Utah, Virginia, Washington and Wisconsin, with more to come," writes John Donovan, senior executive vice president of AT&T Technology and Operations in a blog post.
VoLTE uses the 4G network for calls, converting the voice calls into packets over LTE. Carriers have been falling back to their 3G networks for voice calls so far.
"Our internal testing shows the VoLTE network performance is strong," writes Donovan. "In our launched areas, we've tested how easily consumers can place a VoLTE call (accessibility) and how likely they are to stay connected to the VoLTE network during calls (retainability)."
For the month of November, Donovan reports 99 percent success in both accessibility and retainability testing overall.
"We are committed to delivering an outstanding customer experience with our VoLTE rollout, and will continue to optimize, test and expand our VoLTE coverage throughout 2015," he notes.
Donovan also confirms that AT&T is working with carriers other than Verizon on interoperability testing to make VoLTE calls across networks. (See AT&T's Rinne: Carriers Working on VoLTE Interoperability and Verizon, AT&T Plan VoLTE Harmony in 2015.)
Of course, at the moment, it can be difficult to make a HD VoLTE call even if both users are on the AT&T LTE network. This is because devices with HD VoLTE support, such as the iPhone 6, are new on the market. Donovan is expecting to see more compatible devices out for the holiday season and in 2015, too.
— Dan Jones, Mobile Editor, Light Reading