Overview |
Main Features |
Waveform/Spectral Viewer
Voice Quality Testing (VQT) Results |
Buyer's Guide
Overview:
Testing on the extreme end-point of a network has become a priority for many people. This method of testing represents what an
end user is actually experiencing.
Voice quality testing within VoIP and PSTN networks is growing, a major concern is testing the VoIP phones and the analog Telephone
Adaptors (ATA) that will be used within the VoIP/PSTN networks. The VoIP phones and ATA's must be free noise and other hindrances that
may cause a degraded voice quality when using this equipment. The GL VQuad™ software combined with GL's
Voice Quality Testing (VQT) software permits this desired VQT testing, of the VoIP equipment, yielding results that include
PESQ/PAMS/PSQM+ Mean Opinion Scores (MOS). These results provide an excellent overall measure of voice quality of the equipment
under test.
The Universal Telephony Adapter (UTA) supports interfacing between the telephone and the handset, allowing audio to be injected
and recorded through the phone and across the given network. The UTA can interface with most phone handsets, including VoIP,
Analog and Digital phone/handset combinations.
The GL VQuad™ with the UTA provides the ability to automatically test after the call has been established. Up to four UTA's may be
connected to a single system, all utilizing the same VQuad™ application. Using the VQuad™ software, the user may configure automatic
generation and reception of voice files over an already established call. Once the call is established, the user may manually start the
GL VQuad™ (or configure the GL VQuad™ to start automatically based on system time). The VQuad™ software is solely responsible for sending and
recording the voice files, thus allowing the Voice Quality measurements to take place.
The GL VQT utilizes three widely accepted algorithms to perform the voice comparisons, the Perceptual Evaluation of Speech
Quality (PESQ LQ/LQO) per Rec. P.862/P862.1, the Perceptual Analysis / Measurement System (PAMS) per Rec. P.800, and the
Perceptual Speech Quality Measurement (PSQM) per Rec. P.861. PESQ provides an objective measurement of subjective listening
tests on telephony systems. PAMS predicts overall subjective listening quality (a human's perception of quality) without requiring
actual subjective testing (a very expensive and time-consuming process). PSQM predicts subjective quality of speech codecs without
requiring subjective testing. The GL VQT performs PESQ, PAMS, and PSQM (+) simultaneously, using two voice files (Reference File
and Degraded File) and provides the algorithm results along with analytical results in both a graphical and tabular format.
Main Features:
- Connect to any phone with a handset
- Test VoIP, Analog and Digital Phones, thus allowing VoIP ATA testing'
- Up to four UTA's connected to a single system.
- Automatic send/receive of voice files over already established calls
- Time/Digit/Tone triggering of send/receive voice files.
- Compact and portable solution for testing end-to-end voice quality
- Synchronized software for sending/recording of voice files at multiple locations
- Flexible architecture and features for recording locations, parameters, and time
- GL VQT Automatic Mode allows automatic execution of the VQT algorithms (PESQ LQ/LQO, PAMS, PSQM+).
- Additional measurements include Clipping, Jitter, Latency, Noise and Signal Levels.
- Results available in real-time or post-processing
Waveform/Spectral Viewer
The GL VQT software can be user-configured to provide a rating of each measurement based on the scores, latency, clipping, etc.
A poorly rated measurement can be viewed in graphical format using the waveform viewer. Dropouts, noise and other impairments
can be examined here.
Screen Shot of Waveform/Spectral Viewer
Voice Quality Testing (VQT) Results
GL's VQT may be executed automatically (real-time and/or post-processing) or manually by entering a Reference File and Degraded
File. Regardless of how GL's VQT is initiated, algorithms for PAMS, PSQM, PSQM+, PESQ MOS and PESQ LQ are executed simultaneously
for the two voice files and results are shown graphically as well as in a tabular format. GL's VQT also displays cumulative statistics for
large scale testing over long periods of time.
Screen Shot of PESQ Measurement Window
Screen Shot of VQT Measurement Results
Screen Shot of VQT Cumulative Statistics
Buyer's Guide:
* Specifications are subject to change without notice.
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