POLQA Test Service
Serves to determine MOS values (Mean Opinion Scores), the next-generation voice quality testing technology for fixed, mobile and IP based networks
The POLQA coalition formed by OPTICOM, SwissQual and TNO is the outcome of the competitive standardization process run by the ITU-T (International Telecommunication - Telecoms). It spent more than four years on developing and evaluating various candidate algorithms to find a suitable successor to PESQ. OPTICOM, thereafter SwissQual and TNO have agreed to combine their expertise a joint and uniform solution – POLQA.
Recommendation ITU-T P.863 defines a single algorithm for assessing the speech quality of current and near future telephony systems that utilize a broad variety of coding, transport and enhancement technologies. The measurement algorithm is a full reference model which operates by performing a comparison between a known reference signal and a captured degraded signal. The test set of ITU-T P.863 covers the following languages: American English, British English, Chinese (Mandarin), Czech, Dutch, French, German, Italian, Japanese, Swedish, Swiss German. POLQA is not open source and also there is no public source code available for download from the ITU-T website. The purpose of the objective ITU-T P.863 model is to predict overall listening speech quality from narrowband (300 to 3'400 Hz) to superwideband (50 to 14'000 Hz) telecommunication scenarios as perceived by the user. ITU-T P.863 algorithm cannot be used to replace subjective testing.
Leading test & measurement manufacturers have adopted POLQA/P
More information:
2. http://opticom.de/
3. ITU-T P.863 - Methods for objective and subjective assessment of speech quality
Fig.1 Comparison of perceptual quality methods
Fig.2 Overview of the basic philosophy used in ITU-T P.863
Test factors |
Speech input levels to a codec |
Transmission channel errors |
Packet loss and packet loss concealment |
Bit rates if a codec has more than one bit-rate mode |
Transcodings |
Acoustic noise in sending environment |
Effect of varying delay in listening only tests |
Short-term time warping of audio signal |
Long-term time warping of audio signal |
Listening levels between 53 and 78 dB(A) SPL in superwideband mode |
Packet loss and packet loss concealment with PCM type codecs |
Temporal and amplitude clipping of speech |
Linear distortions, including bandwidth limitations and spectral shaping ('non-flat frequency responses') |
Frequency response |
What PAL can provide?
PAL has been certificated as 3rd party of Dell for IT production noise validation, Microsoft for audio/video qualification and Skype for audio/video certification. In recent years, PAL has invested many works in establishing VoIP test capability. We own qualified audio test environment and precision facilities and provide professional services that conformed to ITU-T standards. Another, the engineers are full of acoustic expertise. PAL also can provide consultant service for trouble-shooting.
If you need more detail information, please contact with PAL’s sales representative, Grace Wung
E-mail: grace_wung@pal-acoustics.com
Phone: 886-2-26272515 ext 113