Performance Measurement, Evaluation and Analysis of Push-to-Talk in 3G Networks

Push-to-talk over cellular (PoC) is considered as one of important applications in next generation networks (NGN). The main objective of this study is to investigate the performance of our PoC system evaluated over three operational 3G networks in the US. Measurements are conducted in two stages. First, several generic measurements such as round trip time (RTT), UDP, TCP, and dormant mode are made to understand the fundamental characteristics of 3G packet switched (PS) networks for the voice and data transmissions of the PoC service. Next, various parameters and features in our PoC software are tested to evaluate the performance of startup latency, voice latency, and voice quality. In conclusion, through empirical study we have shown that PoC applications can achieve high quality in current 3G PS networks. Furthermore from these results we study the network requirements to be solved in NGN for the voice and data communications.