The top two US operators – AT&T and Verizon Wireless – plan to enable interoperable Voice-over-LTE (VoLTE) services next year.
The move will be a major boost to the nascent VoLTE market, given the size of the two operators (more than 220 million connections combined, according to GSMA Intelligence).
Although both companies launched VoLTE services earlier this year, interoperability has been lacking in the VoLTE market to date and is seen as a crucial way for the technology to gain traction. As well as the US, interoperability work is going on behind the scenes in China, Japan and South Korea.
VoLTE is an all-IP technology that delivers voice calls over a 4G LTE network instead of the traditional voice network. VoLTE is claimed to be a much better bet in terms of voice quality and call performance than either 3G circuit-switched voice or Skype. South Korea’s three national operators and US operator MetroPCS (now owned by T-Mobile) were the first to commercially launch the technology for use only between their own customers, back in August 2012.
A joint statement today from AT&T and Verizon noted that engineers from both companies are “working through a full set of requirements, beginning with extensive testing in lab environments and then moving to field trials.” No specific timeframe was put on the “2015” interoperable launch date.
The statement added that interoperability of other Rich Communications Services (RCS) will follow, such as video calls, rich messaging, “and more.”
The two firms are leaving the door open for other operators to join them.
“We’re pleased to be working with AT&T as our first interoperating carrier, and we look forward to working with other operators as VoLTE continues to grow,” stated Tony Melone, chief technology officer at Verizon.
“Interoperability of VoLTE between wireless carriers is crucial to a positive customer experience,” added Krish Prabhu, president, AT&T Labs and CTO, AT&T. “Customers expect to be able to connect anywhere, anytime – and as LTE technology continues to evolve, it’s imperative that we provide a seamless experience between carriers. We are pleased to work with Verizon on this initiative. We continue to work with others in the industry on similar collaborative arrangements and hope to see similar collaboration across the industry in the near future.”
Meanwhile outspoken T-Mobile CEO John Legere reacted to the news in typical fashion (the operator launched VoLTE services within its own customer base in May). “Hell has frozen over. AT&T and Verizon Wireless are working together on something, but scared to mention us too?” he tweeted. In another tweet he wrote: “We’ve been testing cross-carrier HD Voice and VoLTE for a while – ’bout time the other guys catch up! We’re ready when you guys are!”