Voice over LTE finally finds a unified home

Given that 'voice' has only ever been the one true killer app for mobile technology, it now seems difficult to believe that prior to this year's Congress the industry was split on the best approach to providing voice and text services over next-generation (all-IP, data-focused) LTE networks. This uncertainty is all the more surprising given the fact that LTE networks are already a commercial reality in Sweden and Norway and will be switched on throughout China, Japan and the US by the end of this year. However, news that more than 40 organisations – including operator titans such as AT&T, China Mobile, Telefonica, Vodafone and Verizon Wireless; vendors Alcatel-Lucent, Ericsson, Nokia, NSN, LG, Qualcomm and Samsung; and industry bodies NGMN Alliance and 3GPP – have thrown their weight behind an IMS-based initiative looks set to unite this previously fragmented sector.

The initiative – dubbed VoLTE (Voice over LTE) – was previously known as One Voice and will now be led by the GSMA, which expects to complete production of specifications (that will enable interconnection and international roaming) by the first quarter of next year. Verizon's support for the IMS approach was particularly telling, especially given the US operator's new partnership with Skype (also announced last week). However, Verizon played down the idea of using Skype as its voice solution for LTE networks, stating that its 3G EV-DO network will be used for voice services during the early stage of LTE launch, whilst the IMS (VoLTE) solution is being developed. General long-term industry support for VoLTE is likely to sound the death knell for rival initiatives such as the VoLGA (Voice over LTE via Generic Access) Forum, which touts a circuit-switch-over-packet approach to the issue (where the circuit-switch voice or SMS traffic is tunnelled over LTE). Although a number of vendors signed up to VoLTE have also previously pledged support to VoLGA, it's telling that VoLGA can only claim one operator member (T-Mobile, also now a supporter of VoLTE). At best, VoLGA will serve as an interim solution on the path to IMS, a battleground where it could compete with a 'circuit-switch fallback' approach (another interim solution championed by the NGMN Alliance).

(This article is part of a series of follow-ups on Mobile World Congress 2010 from the GSMA Intelligence team.)