Virtual Office Featured Article

Tests Show VoLTE Consumes More Power than Regular Calls

December 10, 2012
By Mae Kowalke, TMCnet Contributor

Did you just feel that bump? The jarring sensation some in telecommunications industry felt recently was the discovery that VoIP over LTE (News - Alert) (VoLTE) consumes more energy than regular cellular calls using other mobile technology. Twice as much power, in fact. Ouch.


The discovery was made by Spirent Communications (News - Alert), which tested battery use when running VoIP over an LTE network. It found that VoLTE took twice as much power as voice using conventional cellular technology. The testing a measurement company, a subsidiary of Metrico Wireless (News - Alert), tested LTE using phones similar to those offered by MetroPCS, currently the only U.S. operator offering VoLTE, according to Stuart Zipper at Phone.com.

“I’ve got a lot of hope for the eventual emergence of VoIP services over Long Term Evolution (LTE) wireless, indeed of VoIP over LTE (VoLTE) replacing VoIP over the non-wireless technologies of today,” wrote Zipper. “But getting there isn’t going to be quite as simple as some think it will.”

The tests revealed that a 10-minute call using CDMA technology consumed 680 milliwatts (mW) of power, while a VoLTE call ate up 1,358 mW. That meant that the phone being tested would yield 502.6 minutes of talk time on CDMA but only 251.8 minutes using VoLTE. This definitely is a setback for VoLTE advocates, and for 4G LTE in general. But at least Zipper thinks that it is just a temporary setback.

“In my opinion, what we have here is little more than a bump in the road, an engineering challenge that the industry will overcome pretty rapidly,” wrote Zipper. “The latest finding may delay some aspects of VoLTE by a bit, but I’m quite confident that in the grand scheme of things, in retrospect the delay will be miniscule.”

It needs to be remembered that the vast majority of phones currently consume both traditional voice and data, whether GSM or CDMA. So while it is true that VoLTE consumes more energy than older voice technology, running voice over VoLTE isn’t necessarily going to cause the drain that the Spirent test implies.

That’s because if a voice call over CDMA takes place at the same time as LTE data transmission, the battery will drain even more than a VoLTE call happening at the same time as a LTE data transmission. There are two radios consuming power with the CDMA and LTE combo, only one when all traffic is going through LTE.

So the finds show that data transmission consumes more power than DMA transmission, but data transmission isn’t going away so the obstacle must be overcome anyway. Then there might even be an energy savings.

“The other thing to consider is that the power issue is not a consideration for desktop phones which, as I’ve predicted, will eventually start migrating to LTE,” added Zipper. “After all, LTE can dish up massive bandwidth, of more than 100 Mb/s, more than enough for dozens of simultaneous VoLTE conversations.”

So yes, there was a bump. But not, it won’t ultimately matter all that much.

Want to learn more about the latest in communications and technology? Then be sure to attend ITEXPO Miami 2013, Jan 29- Feb. 1 in Miami, Florida.  Stay in touch with everything happening at ITEXPO (News - Alert). Follow us on Twitter.




Edited by Amanda Ciccatelli

View All