Impact of IP channel parameters on the final quality of the transferred voice

Ing. Oldrich Slavata

Department of measurement, Faculty of electrical engineering, Czech technical university in Prague, slavao1@fel.cvut.cz

The trend of the twenty-first century is the gradual merging voice and data network. The goal is the most efficient use of existing lines and switching facilities to meet user demand for faster and more stable connection. Transferring a call via internet network presents its own specific problems. To assess the quality of voice transmission is used scale MOS (mean opinion score).




sample length
12s120s
subjective testcurrent standard (ITU-T)problems with concentration, recency effect
objective algorithmirregular distribution of failuresrequired for proper evaluation
My thesis deals with searching connections between characteristics of IP channel and final voice transmission quality.



The second problem that I want to focus on is difficult applicability of current standards for subjective tests (ITU-T P.800, P.830, P.862.3) to certain types of disorders of IP network (packet loss, delay variations).