Link to the complete post: http://www.3glteinfo.com/volte-battery-issue-and-solution-from-st-ericsson-20130
Lately there has been much attention on battery life for devices supporting the new
telephony system for LTE known as VoLTE. They main source of the underlying data is a
measurement report by Metrico made in MetroPCS’ CDMA+LTE network in late
November. It has since then been quoted and analyzed by many media and analysts
For obvious reasons, this white paper does not disclose detailed data about STEricsson’s
products and will instead try to shed some light on the underlying mechanics
and also make some projections of what can be expected in well-designed, commercial
VoLTE devices compared to what is available in the market in the fall of 2012.
First of all, without VoLTE CDMA/LTE systems suffer a severe penalty in that they use a
concept called Simultaneous Voice and LTE – SVLTE. This means that during a voice
call, both the CDMA radio and the LTE radio are in full operation. The consequence of
this is clearly visible in the Metrico data, which also shows the obvious fact that
VoLTE+LTE consume less power than CDMA+LTE.
LTE networks with a 3GPP-based legacy do not suffer this. Neither do CDMA+LTE
solutions based on fall-back schemes (such as the one used in iPhone 5).
When LTE and VoLTE where standardized years ago, great care was put into making the
system and the service as energy-efficient as possible.
Much of the media attention has been on first generation VoLTE implementations based
on first generation LTE chipsets. Chipsets developed with a focus on time to market and
on plain data services rather than more complex ones.
Given its long experience in wireless technology, ST-Ericsson has put its aim much higher
and is currently launching LTE solutions which will demonstrate a completely different
performance compared to what is currently on the market.
This white paper will offer some simple back-of-an-envelope calculations indicating the
kind of performance you will soon see in LTE phones in a shop near you.
Apart from the radio usage scheme used (single/double), there are really three major
factors influencing the battery life of a VoLTE enabled smartphone; software
architecture, radio hardware and transmission protocols.