Collaborates with the Signals Research Group Collaborate to evaluate Enhanced Voice Services to prove the benefits of EVS codec
Spirent Communications and Signals Research Group (SRG) have revealed their latest collaboration to evaluate Enhanced Voice Services (EVS) in the Lab and Live Network. With global interest in the 3GPP-defined EVS5, the two recently executed back-to-back studies to explore the benefits and user experience of this promising voice services codec.
The EVS codec is designed to support high quality and high efficiency and has intrigued wireless operators worldwide. Unlike its predecessor, AMR, which was used for initial VoLTE deployments and marketed as “HD Voice”, EVS was developed and optimized specifically for LTE. EVS is a feature-rich codec that supports everything from narrow band (NB) to super wide band (SWB) with bit rates starting at 5.9 kps to 128 kps and a multitude of advanced error treatment capabilities.
Michael Thelander, President of SRG said, “Naturally, we were excited to take a close look at the promises of this new voice codec. With all the hype over what EVS can deliver and the many features and deployment options for carriers, it is a great opportunity to evaluate many different use case scenarios and benchmark performance results. We ran round one on Spirent’s Elevate test system in the lab using Spirent Nomad to measure audio quality and then took the same Nomad measurement system to the field on a commercial network. The bottom line, EVS outperforms it predecessors and exhibited significant benefits.”
“Behind the VoLTE Curtain, Part 5” provided the industry’s first independent performance analysis of EVS and how it compares to AMR under a wide range of conditions in a tightly controlled lab environment. The Spirent lab configuration enabled precise control over the conditions (clean channel and noise) as well as the introduction of IP impairments including delay, jitter and packet loss which led to several key findings.
According to the release, the EVS codec, when configured to operate in super wide-band mode, can deliver superior voice quality to AMR-WB while simultaneously consuming fewer network resources. With noise in the channel or IP impairments the benefits of EVS are very evident especially with EVS –SWB. The quality and tuning of the audio circuitry can have an impact on the voice quality and potentially negate the benefits of the wider bandwidth and higher bit rate codec options.
Signals Research Group has partnered with Spirent for over a decade on various benchmark studies with the EVS studies being the most recent chapters in a two-year focus on the investigation and evaluation of all VoLTE-related activities including VoLTE vs OTT, Video telephony and VoWiFi. Spirent and SRG plan to continue exploring additional EVS testing in the lab and are preparing a second round of video testing in both lab and field – stay tuned for more exciting results.
