Verizon Wireless, AT&T and several major international carriers and vendors threw their support behind an IMS-based approach to delivering voice and SMS services over LTE networks. The level of operator support--the approach also is supported by Orange, Telefonica, TeliaSonera and Vodafone--sits in sharp contrast to another approach, called Voice over LTE via Generic Access, or VoLGA, which is supported by T-Mobile International.

Vendors including Alcatel-Lucent, Ericsson, Nokia Siemens Networks, Nokia, Samsung Electronics and Sony Ericsson also voiced their support for the initiative, dubbed One Voice. The companies said they concluded that an IMS-based approach "is 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."

The companies said that the purpose of the init