Experimental Setup for Subjective Evaluation of Interactive Multimedia Quality over IP Networks

Project Type: Master/Diploma Thesis
Student: Bräuer Franz
Mentor: Gernot Kubin


 Human perception of Voice- and Video-over-IP connection quality is influenced by many factors, first of all the network conditions like packet loss rate, delay and jitter but also others like the hard- and software (speech or video codec) in use. In this thesis an experimental setup is presented which allows adjustment of certain network parameters to study their impact on the perceived connection quality. In the first part of this work the implementation of the laboratory setup is documented in detail. The second main issue of this work is finding suitable test scenarios for the subjective assessment of Voice- and Video-over-IP connections. Existing VoIP scenarios are adapted to include assessment of the video connection, and also a new scenario is thought up. These scenarios are examined in a first user assessment involving 12 voluntary test persons. In the third part the results of a more comprehensive test session involving 28 test persons are presented. The test showed that users seem to tolerate delay to a large extent, even if the delay times are beyond the 400 ms threshold that is recommended by the ITU.