Dynamic QoS and Network Control for Commercial VoIP Systems in Future Heterogeneous Networks

This work examines new QoS models and dynamic network control methods for new commercial VoIP solutions. The R equation, derived by ITU for network planning that forms part of the E-Model (ITU-T G.107), has been the backbone of Quality-of-Service (QoS) prediction of telephony for decades and it has been very successful in predicting the Mean Opinion Score (MOS) and QoS for telephone systems. However, we question its applicability to Voice-over-IP(VoIP) systems and propose a preliminary VoIP equation, called VoIP-eM. We propose our own research directions and testing methodology to examine the new equation and new QoS model for dynamic control. Our work examines the assumptions behind the ITU-T E-Model R equation including the linearity of the disparate transmission parameters, the random assumption behind the packet loss and interpretation of Id and Ie equation parameters representing impairments due to echo and delay, and impairments from transmission equipment, respectively. Further examination into the combined behavior of packet loss and packet delay, and other impairment scenarios including various environmental factors based on our background and noise conditions will also form a part of this investigation. In addition, demographics and languages spoken may show the variability in the R to MOS prediction and will therefore be investigated. The new QoS models will be evaluated for CODEC G.711, G.729, AMR, and GSM-FR. The proposed work will lead towards developing a dynamic QoS and network control system for heterogeneous VoIP networks integrated into a middleware based solution for industry.