User's Manual Part 2

Nomad User’s Manual Appendix E – Introduction to POLQA
Copyright © Spirent Communications, Inc. 2013 154
The table below compares PESQ and POLQA at a glance:
PESQ
POLQA
Codecs
 AMR
 EFR
 AMR
 AMR-WB
 EFR
 EVRC
 EVRC-WB
 iLBC
 AMB+
 AAC
 Skype / SILK
 G.711
 G.729
Reference Speech Material
 8 kHz
 8 kHz
 48 kHz
Applications
 POTS
 VoIP
 3G
 HD Voice
 Voice Enhancement
Devices
 Skype Calls
 Benchmarking CDMA and
GSM
POLQA scoring is available as an optional upgrade to Nomad. To configure a POLQA-enabled
Nomad installation for POLQA scoring:
 On the Settings→ Voice Quality tab, set the Default Scoring Algorithm to POLQA.
 When creating a new Voice Quality task, confirm that the Scoring Model in the Session
dialog is set to POLQA.
During a Voice Quality test using POLQA, the Voice Quality Task Status Window displays
Attenuation as the amplitude of the current waveform. Attenuation measures the downlink signal
gain reduced by Nomad. For the best results, Spirent Communications recommends maintaining
downlink attenuation between 0 and 7 dB, ideally as close to 0 dB as possible. Increase Input Level
to decrease Attenuation toward 0 dB. Note that compared to PESQ, POLQA is more forgiving when
it comes to attenuation adjustment.
During a Voice Quality test using POLQA, the Voice Quality Task Status Window displays the
Algorithm as POLQA.