Improvement the performance of voice quality over UMTS system in packet switching networks

In this paper, we review the key features of the air interface of the Universal Mobile Telecom System (UMTS), standardized by 3GPP, in which functionality can be tailored to the requirement of VoIP applications. Then we evaluate the performance of the network and its effect on QoS of VoIP applications by adding a new entity for the system, a router with air interface, instead of a BS (base station) and BSC (base station controller) and using an intelligent mobile terminal (users using SIM cards) of next generation wireless networks, to initiate voice over IP (VoIP), using a session setup protocol, like H.323 Annex. Performance analysis proved that the effect of the proposed configuration enhanced the global evaluation of the voice´s service quality.