Here is the URL for this bookmark: http://www.fiercebroadbandwireless.com/story/study-volte-slashes-smartphone-battery-life-50/2012-11-27
When you think about it though, it makes sense. VoLTE (Voice over LTE) is not using a traditional GSM or CDMA circuit, rather it is using a packet data network to encapsulate the voice traffic - so it is voice over a data network. We've known for a long time that data traffic (particularly higher speed data traffic) uses a lot more power than voice traffic. More power equals less talk time from the same charge.
This study is a US based one, so it brings the luggage of CDMA rather than GSM like the rest of the world uses, but I think there are lessons here for the GSM carriers around the world too. CDMA battery life (from my experience) has been on a par with GSM battery life. I think it would be reasonable to equate the CDMA battery life in this study with GSM battery life.
I am seeing more and more countries around the world clawing back the 2G spectrum for use with Digital TV, LTE or other local requirements. At some point in the future (at least for some markets) the only Voice traffic will be using VoLTE and those subscribers will have severely reduced standby and talk time compared to mobile phones of a few years back. Will that lead to a backlash in the community? By that point it may be too late with the spectrum re-deployed for other uses. Will we end up with VoLTE being the only voice option in some countries and others still having CDMA or GSM voice networks - and will that complicate things for phone manufacturers? (remember the days of so called 'Global phones' that had to be made to cater to all the different spectrums used around the world - yes multi band phones became pervasive, but will so called Global Phones that retain backward compatibility with GSM networks be so popular when the primary channel for mobile phone distribution is still the telephone carriers themselves (and they have committed to VoLTE in their own country)?
Who knows. I do think that we'll end up with a big group of primarily voice subscribers who aren't going to be happy campers!