Voice over LTE - Top Wireless Technologies in 2013


What is it?
One of the advantages of LTE is IP Multimedia Subsystem (IMS) technology, which allows carriers to deliver voice as a data application. Verizon Wireless (NYSE:VZ), one of LTE's early pioneers, recognized this as far back as three years ago. The IMS approach to Voice over LTE, which has simply become known as Voice over LTE or VoLTE, quickly won out over a competing approach, Voice over LTE via Generic Access, or VoLGA. The multitude of companies that threw their weight behind VoLTE concluded that it was "the most applicable approach to meeting the consumers' expectations for service quality, reliability and availability when moving from existing circuit-switched telephony services to IP-based LTE services. This approach will also open the path to service convergence, as IMS is able to simultaneously serve broadband wireline and LTE wireless networks."

In August 2012, MetroPCS (NYSE:PCS) became the first U.S. carrier to commercially launch a VoLTE device, announcing that its LG Connect 4G smartphone would  be sold with VoLTE support. South Korean carrier SK Telecom also announced the launch of its VoLTE service around the same time. 

Why is it important?
Multiple carriers, including some in the United States, are testing VoLTE ahead of commercial launches. Verizon Wireless (NYSE:VZ) CTO Nicola Palmer recently disclosed the operator expects to begin consumer trials of VoLTE in late 2013 with commercial VoLTE service expected in 2014, two years later than the carrier's initial commercial launch plans. AT&T Mobility (NYSE:T) plans to launch VoLTE sometime this year, and Clearwire (NASDAQ:CLWR) has said it will offer VoLTE when it launches its TDD-LTE network by the middle of 2013. Additionally, U.S. Cellular (NYSE:USM) has started testing VoLTE but has not yet said when it will launch the service.

The industry's move to VoLTE is primarily driven by carriers' desire to reduce the cost of delivering voice traffic. If voice can be delivered an all-IP environment, over time that could let carriers repurpose spectrum currently reserved for legacy voice services. VoLTE also could allow carriers to create more advanced voice services, much like the current crop of VoIP providers are doing.