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Quality of service for voice over next generation networks.

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The Global communications transformation is currently in progress. Packet switched technology has moved from data - only applications into the heart of the network to take up the functions of traditional circuit - switched equipment. Voice over A TM(VoATM) and voice over IP(VoIP) are the two main alternatives for carrying voice packets over NGN' s. A TM offers the advantage of its built in quality of service mechanisms. IP on the other hand could not provide QoS guarantees in its traditional form. IP QoS mechanisms evolved only in recent years. There are currently no QoS differences between Next Generation Networks based on VoATM or VoIP. However non QoS agreements are more in favour of VoIP instead of VoA TM. This gives VoIP the leading edge bet the Voice over packet technologies. In this thesis the E - Model was optimized and used to study the effects of delay, utilization and coder design on voice quality. The optimization was used to choose a coder and utilization levels given certain conditions. An optimization algorithm formed through the E - Model was used to assist with the selection of parameters important to VoIP networks. These parameters include the link utilization, voice coder and allowable packet loss. This research also shows us that different utilization, voice coder and packet loss levels are optimal in different situations. A remote and core VoIP Network simulation model was developed and used to study the complex queuing issues surrounding VoIP networks. The models look at some of the variables that need to be controlled in order to minimize delay.


Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2004.


Theses--Electronic engineering.