MetroPCS today announced that it has become the first carrier in the
world to launch Voice-over-LTE (VoLTE) service, and started selling the
world's first commercially-available VoLTE phone. All previous 4G LTE phones must rely on 3G or 2G networks for
voice calls, requiring two overlapping networks for full service, one
for voice and one for data. The launch of VoLTE permits 4G-only voice
and data, paving the way for the eventual sunset of 2G and 3G networks.
In MetroPCS' case, it will allow the company to shut down its CDMA
network sooner. LTE is more efficient than CDMA, and running two
networks adds its own inefficiencies.
Therefore an accelerated move to
4G LTE-only service will allow MetroPCS to make better use of its
licensed radio spectrum.