User's Manual Part 2

Nomad User’s Manual Appendix E – Introduction to POLQA

Appendix E – Introduction to POLQA

The worldwide prevailing standard for mobile voice quality analysis has been ITU-T P.862, known

as Perceptual Evaluation of Speech Quality (PESQ). PESQ implements automated testing of

telecommunications using actual speech samples, comparison of the reference signal (transmitting

side) to the degraded channel (listening side), and generation of mean opinion scores (MOS) to

model subjective listening patterns. This technique has been widely adopted due to its capability to

automate collections of large sample sets simulating real-world subscriber experience.

As network technologies mature and evolve, the drivers of performance change, and new

methodologies for measuring and assuring quality are required. PESQ is logically being succeeded

by ITU-T P.863, Perceptual Objective Listening Quality Analysis (POLQA).

Advantages of POLQA include:

 Significantly expanded set of codecs, including AMR-WB, EVRC, EVRC-WB, Skype / SLIK,

G.711 and G.729.

 Designed to handle more complex end-to-end network architectures and quality

management techniques such as smart loss concealment and time stretching.

 Two operational modes to distinctly address narrowband and super-wideband

communication.

 Three-fold increase in evaluation set used compared to PESQ, resulting in considerably

smaller residual prediction errors even as the application range has expanded substantially.

 Seamless upgrade path from, and backward compatibility with, PESQ.

POLQA provides more robust quality predictions for:

 Cross-technology quality benchmarking (such as GSM vs. CDMA)

 Noise reduction and voice quality enhancement

 Time scaling, unified communication and VoIP

 Non-optimal presentation levels

 Filtering and spectral shaping

 Recordings made at an ear simulator