10
TEMS
™
AUTOMATIC 8.2
VSQI
Video Streaming Quality Index is a non-reference method for video streaming
quality assessment. VSQI is based on the quality of the encoded (com-
pressed) signal prior to transmission, the amount of initial delay, and the
subsequent interruptions during playback of the video sequence; that is,
the time required for initial buffering and the incidence of rebuffering. It
also takes into account the amount of packet loss at the application level
(in other words, in the video streaming client). VSQI is expressed in the MOS
scale.
VTQI
Video Telephony Quality Index is a non-reference method for assessing the
quality of video telephony calls. VTQI is based chiefly on the block error rate
(BLER) measured during the call, while also considering the quality of the
signal prior to transmission. The VTQI score is expressed as a value in the
MOS scale.
Speech quality
TEMS Automatic offers functionality for advanced speech quality assessment
by testing Mobile-To-Mobile or Mobile-To-Fixed. The Perceptual Evaluation
of Speech Quality (PESQ) and Speech Quality Index (SQI) are two of the most
important parameters when checking voice quality. These parameters can
be compared with each other, which greatly facilitates quality evaluation
analysis by giving a more complete view of speech quality, as well as making
it possible to conclude if a problem is in the fixed or mobile network.
PESQ
PESQ is an objective algorithm used for end-to-end speech quality assessment.
It is the ITU-T P.862.1 standard algorithm for measuring speech quality,
providing scores calibrated to the MOS scale. In addition, TEMS Automatic
includes frequent Audio Quality Measurements (AQM), an objective speech
quality score derived from the PESQ algorithm. An advanced algorithm, AQM
gives quality scores with twice the frequency of PESQ. This makes it easier
to geographically pinpoint speech quality problems and to find the corre-
sponding radio problem. TEMS Automatic also verifies volume, echo, and
silent as part of the PESQ measurements.
TEMS Automatic provides the ability to:
▪
Improve QoS
– By reporting quality trends that show
the impact of optimization efforts on a
daily, weekly, or monthly basis.
– By providing continuous feedback on the
Quality of Service of the live network as
experienced by subscribers, in regards to
both speech quality and data services.
▪
Reduce churn and increase revenue
– By detecting faults, capacity bottle-
necks, and configuration problems imme-
diately – before subscribers do.
▪
Reduce costs
– By allowing field engineers to focus on
planning, troubleshooting, and fixing er-
rors rather than merely collecting data.
– By minimizing the time it takes to create
and distribute quality reports.