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SwissQual, the independent Swiss network quality measurement company, has carried out a mass experiment aimed at understanding how humans perceive “quality” in telecommunication services in order to support the development of a new ITU sponsored measurement standard.
Previous work at SwissQual’s purpose built multi media laboratory in Zuchwil, Switzerland, has shown how our perception of what makes a “good” or “bad” phone call is shaped by a wide variety of factors. These factors include not only issues such as clarity and noise but also such issues as where and how often poor quality occurs within a phone call. This understanding is vital to the development of tools for network quality measurement. To provide a true and meaningful measure of network quality, these tools need to accurately predict how a human being would “feel” about the quality being delivered. SwissQual’s experiments repeatedly compare the predicted quality perception provided by its measurement tools against the actual reported perceptions of live human subjects.
According to SwissQual CEO John May, the in depth understanding which such work provides allows the company to provide a much more accurate result for its customers: “We continually test and refine our own measurement algorithms. This means that SwissQual products are not simply up to date with current ITU standards, but are usually significantly ahead. We can provide solutions with the “industry standard” algorithms but we can also provide solutions with far more advanced technology.”
The current mass experiment has been specifically carried out to support the development of the new objective voice quality measure P.OLQA. This has been launched by the ITU-T in an ongoing project to address some of the known shortcomings in the existing standards ITU-T P.8621 and P.862 ‘PESQ’. The new P.OLQA measure is being developed to incorporate a wide range of telephony scenarios and therefore to provide a much more realistic prediction of quality in “real world” scenarios. Some of these scenarios address current issues and some address issues that are expected to arise in the future and which are not covered by current standards.
One of the main needs of the mobile industry is to understand the direct relationship of different distortion types to each other (i.e. coding distortions against audio band limitations) in order to provide a true benchmarking of complex scenarios. The objective is to enable operators to make the optimum trade off of different factors in order to deliver the best overall quality.
Dr Jens Berger, SwissQual’s Head of Applied Research, leads the related working group in ITU-T for perceptual based objective quality measures for many years and is now coordinating the efforts for the upcoming standard P.OLQA.
Says Dr Berger: “It is very important to carry out these tests according to ITU-T and ETSI standards, since they form the basis for future objective measures. At SwissQual we see the development of these objective measures as being central to the “science of quality”. They therefore remain a core element in our ongoing development program targeting latest technologies and future more ‘audio-like’ telecommunications.”
The company routinely carries out tests in this laboratory to assess the sensitivity of different types of people to a range of telecommunication quality problems. The results of these tests are used for adjusting the predicted scores delivered by SwissQual perceptual psycho-acoustic driven algorithms and network quality test equipment.
SwissQual use the range of SQuad™ (algorithms for voice) and VQuad® (for video) throughout their Diversity™ and QualiPoc® products. The algorithms are also available for use by third parties.
About SwissQual
SwissQual is an independent Swiss company specialising in the quality of service measurement and monitoring of fixed and mobile telecommunication networks. SwissQual offers a wide range of solutions to suit most needs including laboratory testing, radio network optimisation and benchmarking. It is also well known for its pioneering work in voice and video perceptual quality measures. Founded in 2000, SwissQual today has more than 70 employees and serves more than 120 customers in over 55 countries.
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