April 13, 2010 - Respondents to our Evolved Packet Core (EPC) survey are divided on one of the initial issues involved in the adoption of next-generation wireless: integrating new Long Term Evolution (LTE) technology with current 2G and 3G networks.

Existing cellular networks handle voice and data on separate circuit-switch and packet-switch elements, while LTE will combine both voice and data on a single IP architecture. The EPC is the infrastructure used to connect mobile users to applications in an LTE network, supporting mobility and QoS management functions, which will be crucial for voice and video over the all-IP network. (See Who's Ready to Buy Evolved Packet Core?)

As established carriers build out their LTE networks, however, they will still need to support fall-back to voice services over 2G and 3G and handover to the older networks in areas where the newer technology isn't available. In fact, Verizon Wireless doesn't expect to switch to a voice-over-LTE system -- using the IP Multimedia Subsystem (IMS) -- until 2011 or 2012. AT&T Inc. (NYSE: T)'s plan for that switch won't take hold until 2012 or later. Both carriers are expected to keep investing in 3G until the end of the decade.

source: Light Reading | Read Full Story