SwissQual’s SQUAD Updates PESQ Functionality

 

SwissQual, the independent Swiss network quality measurement company, continues its development of the SQUAD family of algorithms to address the limitations of ITU-T recognised MOS predictors when used with network embedded Voice Quality Enhancement (VQE) technology. VQE technology has become widely used by operators; providing benefits such as noise reduction, echo cancellation and gain control. However the ITU-T recommendation P.862 (PESQ), which has been in place, and left unchanged since 2000, shows limitations when applied to some of the recent advances in network technologies. This is particularly true when applied to the Enhanced Variable Rate Codecs (EVRC) used in CDMA networks. As a result, it is now acknowledged in the industry that these limitations make it impossible to benchmark voice quality of CDMA networks against GSM and UMTS networks using PESQ.

Says Pero Juric, SwissQual’s VP of Product Management: “The P.862 standard has provided a very useful tool for the estimation of speech quality.  However, the good work started with that algorithm back in 2000, now needs updating. Part of the need relates to being able to cope with newer VQE technologies, part relates to the need to more closely reflect the way in which mobile phones are used in real life. The actual speech quality delivered by a real network does not necessarily correspond with the listening quality predicted by the speech codec in noise free conditions. In normal “real life”, calls can be subject to noise, echoes, long latencies, gain control and double talk. Clearly, to deliver a true measure of network quality, these issues need to be covered. We have therefore developed a family of objective voice quality metrics called SQUAD to measure all the relevant quality aspects of a voice call under both field and simulated network conditions.

SQUAD has been calibrated with ongoing research into end user perception of quality across a wide range of network conditions, and is proven to be consistent across all network technologies to allow true benchmarking for operators in multi-technology markets.”

SQUAD is delivered as standard in SwissQual’s range of benchmarking, service monitoring and optimisation systems, supplementing or replacing the P.862 quality assessment method. It is also available for third parties on license base.