AT&T has officially announced that it will roll out VoLTE service over its network in select markets beginning on May 23rd. AT&T will be branding the service as HD Voice, but unlike other carriers that are branding the Wideband AMR transmission standard as HD Voice without actually carrying voice calls over their LTE networks and disallowing simultaneous voice/data access, AT&T will allow simultaneous voice and data access with the rollout.
AT&T’s HD Voice service uses VoLTE to pass calls through its LTE data network rather than its current 3G voice network and the only device capable of supporting HD Voice will be the Samsung Galaxy S4 mini, though AT&T says more devices will follow shortly after it launches on the 23rd. AT&T further explained that Samsung worked directly with the carrier to develop this version of the S4 Mini with VoLTE service. AT&T HD Voice will first be available in select areas of Illinois, Indiana, Minnesota, and Wisconsin with more markets launching service during the year.
The launch of VoLTE on AT&T make it the first major carrier in the US to launch the long-expected voice transmission protocol after years of development. MetroPCS previously launched VoLTE service in 2012, but limited it to a small area close to its corporate headquarters in Dallas, TX and only one phone in the brand’s former lineup in the revised LG Connect 4G ever supported Metro’s deployment of the protocol before being purchased by T-Mobile and subsequently halting all network-related development.
While T-Mobile made statements alluding to the maintenance of the MetroPCS VoLTE service shortly after the beginning stages of the purchase in October 2012, the speed in which it rolled out its current LTE network and the transition speed from Metro’s CDMA network since starting last year meant that T-Mobile has essentially abandoned those maintenance plans in favor of moving everyone onto its own HSPA+/LTE network instead.