By: Ed Elkin, Director, IP Platforms Marketing, Alcatel-Lucent 

There’s been a lot of debate within the industry about VoLTE’s readiness and how it stacks up against 3G voice and applications like Skype.

Now Signals Research Group (SRG), a leading field research and consulting services leader covering the wireless telecommunications industry, has closely studied the performance of VoLTE, 3G and Skype in AT&T’s commercial network and issued their report.  As we noted last week, SRG conducted that independent network benchmark study in Minneapolis-St. Paul, in collaboration with Spirent Communications. This is a market where Alcatel-Lucent provides the infrastructure, so I’m particularly glad to share this report with my friends and colleagues who’ve helped design, deploy and optimize VoLTE. 

During June and July, SRG tested VoLTE, 3G and Skype for everyday conditions, including stationary and mobile locations, strong and weak radio coverage, and under a variety of network loading and multi-tasking conditions. The tests evaluated voice quality, call setup time, call reliability, eSRVCC handovers, network resource utilization, and battery life.

For subscribers, SRG concluded VoLTE delivers superior call quality even for weak radio coverage and loaded networks, along with faster connectivity and substantially less battery drain. For the operator, VoLTE consumed fewer network resources than Skype.

The SRG report states: “Whenever we do these types of studies we are always fearful that the results will fall short of our expectations and we will be in the precarious position of telling proud parents that their baby is less than beautiful. Fortunately we were not faced with this situation after completing the first part of the VoLTE study. VoLTE generally lived up to our expectations.”

The SRG results should settle the industry debate. A voice app such as Skype was shown to require a sunny day situation in order to sound good:  strong radio signals, little network loading, and no multi-tasking. VoLTE works all the time, including everyday conditions.  VoLTE’s audio fidelity is better: our voice tones are richer and warmer, and we don’t have annoying latency or lost audio during calls. Plus VoLTE provided significantly longer battery life than Skype, and only a bit less than 3G.

VoLTE’s user experience also beats 3G Circuit Switched Fallback (CSFB).  Calls were setup nearly twice as fast as CSFB.  VoLTE’s voice quality was measurably higher due to intrinsic AMR-WB, which isn’t in that 3G UMTS network. Particularly important for today’s data-hungry people, VoLTE subscribers get faster broadband, because LTE is always available, including voice calls.

SRG also measured how VoLTE provides efficient network utilization.  Its design shrinks the packet header so that it consumes less radio bandwidth (Robust Header Compression); it requires fewer scheduling grants and resource blocks; it provides better coverage (TTI-Bundling); and it takes greater advantage of techniques such as discontinuous reception or transmission (DRX, DTX).  When compared to Skype that means VoLTE ensures the LTE cell has more capacity for broadband data services. 

For consumers and enterprises, VoLTE is the clear winner. It provides a superior experience while simplifying everyday communications. VoLTE enables anyone to talk clearly while simultaneously browsing the Web, downloading videos, sending emails, playing games or sharing content at LTE speeds.