OPTICOM and SwissQual’s initiative enables ITU-T SG12 to add new Implementer’s Guide to Recommendation P.863

POLQA (www.polqa.info), the global standard for benchmarking mobile voice quality can now also be safely applied to characterize EVS coded speech signals. Under the leadership of OPTICOM and SwissQual, both co-authors of the POLQA standard, successful validation results were recently reported to the January meeting of ITU-T study group 12. Based on this analysis, the ITU-T released the new ‘Implementer’s Guide on assessment of EVS coded speech with Recommendation ITU-T P.863’, which is now available from the ITU website. As a result, commercial T&M devices running POLQA version 2015 (v2.4) are already validated for EVS support, although OPTICOM and SwissQual might offer updated OEM DLL versions in the course of software maintenance.

Recently, 3GPP SA4 (www.3gpp.org) released the new Enhanced Voice Services (EVS) Codec[1] for advanced voice services over LTE networks. EVS, also referred to as “Full-HD Voice”[2], is designed to deliver superior voice quality, and more efficient usage of the available network bandwidth. While currently the audio bandwidth for voice calls in mobile networks is limited to either traditional telephony band, or an extension to 7kHz-wideband – also known as “HD-Voice” – EVS will even support wider bandwidth that spans over the full audible range of the human ear. This new mode will be known as Full-HD Voice.

Naturally, this latest codec development was not foreseen at the time when POLQA, the 3rd generation of perceptual voice quality measurement, was standardized by the International Telecommunication Union (ITU-T) as recommendation P.863, neither in 2011, nor at the latest revision in 2014. Consequently, OPTICOM, SwissQual and TNO, members to the POLQA coalition joined forces to investigate and validate how well POLQA would perform for services using EVS technology. Subjective tests at independent sites, comparing EVS with commonly used voice codecs, were conducted by the coalition to collect data and validate POLQA’s measurement accuracy. The outcome of these studies proved that POLQA is very well suited to be used in conjunction with EVS, especially in Full-HD voice mode. For the traditional and restricted bandwidth modes of EVS, POLQA also shows reliable results. Based on this new guideline, POLQA can be safely applied together with networks utilizing EVS.

The results of OPTICOM and SwissQual were reported to the recent study group meeting of ITU-T SG12 in January 2016 along with a similar study, contributed by one of the co-developers of the EVS codec. The meeting decided to publish all the findings provided by the individual contributions in the form of an Implementer’s Guide for P.863.

Recognising that ITU-T Rec. P.863 supports 14 kHz super-wideband as the main extension towards Full-HD-Voice, the POLQA Coalition also identified the need to continue working towards an extension of POLQA for fullband applications in the near future, along with further advancements and improvements in the course of ongoing Standard’s maintenance.

[1] http://www.3gpp.org/news-events/3gpp-news/1639-evs_news
[2] http://www.full-hd-voice.com/en/what-is-full-hd-voice.html