Evaluating the NGN performance based on duplicate transmission of voice packets

Abstract

This work aims to enhance the Quality of Service (QoS) of the third-generation (3G) cellular networks. The quality of voice traffic over IP networks (VoIP) is greatly reduced due to the fact that packets in IP networks suffer from packet loss which is inevitable due to the best-effort nature of these networks. Many techniques have been proposed to decrease the effect of packet loss on the speech quality. In this paper we study the effect of packet loss on speech quality; we propose sending a duplicate copy of the speech stream over the network and we study the effect on the speech quality due to this duplication. This is especially useful in networks with extra available bandwidth. The performance of the system is measured according to the E-Model as defined in the ITU-T's Recommendation G.107. The speech sources used during the experiments are artificial voices obtained from the ITU-T Recommendation P.50/Appendix I. The results of the proposed scheme suggest improvement in the system performance in terms of speech quality which can then be translated into greater percentage of users satisfied with the service and greater potential revenue. The proposed technique proves to be more effective when situations of higher percentages of packet loss and burst losses rise.