VRÁNOVÁ, Zuzana; BEŠŤÁK, Robert; ONDRYHAL, Vojtěch. Speech signal quality assessment for different VoIP technologies. In: Proceedings of the International Conference on Military Technologies 2011, ICMT’11. Brno: University of Defence, 2011, p. 1177-1184. ISBN 978-80-7231-787-5.
SUMMARY: The new phenomenon in the communication world is called the convergence of telephony and data network in IP based principles. In line with global trends the structure of communication and information systems of the Armed Forces of the Czech Republic (ACR CIS) is undergoing profound changes. However, the modernization process brings not only economical advantages, but also many technical problems. One of the main challenges seems to be quality of speech signal in VoIP transmission channel. Nowadays, there are many standardized subjective and objective sophisticated methods of speech quality evaluations. Based on the knowledge of them and ITU-T standards, we have developed specific testbed and procedures to verify and compare the signal quality when using TDM and VoIP technologies. The presented results are obtained from the measurement done on systems which perform in the ACR network.
Keywords: VoIP, Signal Voice Quality, G.711, MOS, R-factor.