Introduction; What Is Opera - OPTICOM OPERA - V 3.5 User Manual

C H A P T E R 1 :

1 INTRODUCTION

An Introduction to the OPERA™ Measurement
System and the OPERA™ Product Family.
À
fter reading this chapter you will be familiar with the basic ideas and
the concept behind this tool. The OPERA™ product family will be
outlined at the end of this chapter.
1.1 What is OPERA™?
Compression
communications – thus allowing for a great number, diverse and inexpensive
new components of the information age, such as: mobile phones, VoIP, MP3
internet audio, radio and TV satellite networks, DAB, DVD, and many more.
On the other hand the economic benefit of lowering data rates to a minimum is
contradictory to clear sound. In spite of "all digital technology", sound quality
and the intelligibility of speech have become issues again, and are of much
more impact than in those "good old analog days".
Our new generation of quality testers, called OPERA™ – short for "Objective
Perceptual Analyzer" – represent the latest development in objectively
evaluation and assure the quality of compressed speech and wide-band audio
signals by modelling the human ear: OPERA™ is your digital ear. OPERA™ is not
only suitable to assess a single processing device, with OPERA™ you can
achieve a comprehensive analysis of the end-to-end quality, from the studio
source to the receiver, or from the caller to the callee. And because OPERA™
works quite similar to the human ear, it is able to distinguish between
imperceptible, and more or less annoying transmission errors.
Other than traditional measurement methods (like S/N, THD+N), the new
OPERA™ system is able to simulate the subjective evaluation of human subjects.
The analysis is based on the most recent perceptual techniques, such as PEAQ,
PESQ and PSQM. As a major advantage, OPERA™ employs the same kind of
natural stimulus for a measurement as in practical operation: human speech or
music program material. Moreover, this makes it possible to monitor the
quality during network operation. Cultural and language differences may be
taken into account by the evaluation as well. As a consequence of the novel
approach to measure the perceived audio quality instead of signal
characteristics, it is possible for the first time to gain an objective quality metrics
which truly characterizes the quality of service („QoS") of a network.
I N T R O D U C T I O N
has become state-of–the-art technology
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in modern
1
Chapter