AT&T Chicago store (interior 001)

United States carrier AT&T said yesterday that some of its customers in select areas can now make Voice-over-LTE (VoLTE) calls to users on other carrier networks. Cross-network VoLTE calls are currently supported for just one unnamed carrier, but AT&T will eventually implement support for multiple carriers.

Unlike traditional calls that use a carrier’s voice network (which is separate from a 3G/4G data network), VoLTE calls use a 4G Long-Term Evolution (LTE) network, resulting in crisp sound quality and optimized bandwidth use.

“I’m pleased to report this month we saw the first VoLTE exchange between our customers and another carrier in limited, select areas,” wrote AT&T’s Bill Smith. “We’re working with others on this same feature, too.”

AT&T’s VoLTE network currently covers about 295 million Americans, with more than 27 million active subscribers.

Other advantages of VoLTE technology on iPhones include the ability to simultaneously surf the web and talk at 4G speeds and support for HD Voice technology which produces more natural sounding audio by extending the frequency range of the audio signals, resulting in “remarkably clearer calls.”

To see if AT&T’s VoLTE network is available in your area and for your device, check out AT&T’s coverage viewer.

Source: AT&T