Calls conducted on VoIP over LTE (VoLTE) consume twice as much power as those over a 2G CDMA network an investigation has found.

Radio field testing company Metrico Wireless, now part of Spirent, found that power consumption during a ten-minute VoLTE call was 1358mW compared to 680mW on CDMA circuit switched. According to GigaOM, the tests were likely to have been conducted on an LG Connect 4G on the MetroPCS network in the US, as this is the only commercially available VoLTE handset on the only US network to offer VoLTE.

As a result of the findings, battery life on the handset would drop from 502.6 minutes of CDMA call-time to just 251.8 minutes of VoLTE.

The first LTE capable phones were known for their poor battery life and flipping between circuit- switched voice calls and LTE for data were said to be one of the key reasons for this, so the poor battery performance of VoLTE calls will be of concern for the industry.

However, it is just one test, on one handset on one network, and performance is likely to improve once optimisations are made, Spirent Global Director of Insights Amit Malhotra told GigaOM, ““The disadvantage in battery life of VoLTE compared to circuit-switched voice is driven by a few different factors. One is the more strenuous exercise of the device, including conversion of voice to packet data, transmission and receipt over the data network, and reconversion back to voice. Another is the use of less power-efficient components such as data modems versus voice transceivers.”

However, the handset was found to use less power when making a VoLTE call and using data, than when making a 2G calls and using data.

Put the date in your diary now for the inaugural LTE Voice Summit, taking place in London in October 2013. Click here NOW to download a flyer.