Análise de QoS em aplicações VoIP em dispositivos móveis

Abstract

This paper aims to compare the QoS of Whatsapp and SOMAapp applications in scenarios in which factors of variation of network conditions were used such as delay, packet loss and jitter and also a configuration of the transmission rate at 10Mbps. The applications were submitted to all scenarios. In each scenario a call is made by Whatsapp and another by SOMAapp, which are made between two smartphones and transmitted audio. The audio captured on the smartphone that received the call is the audio that suffered network degradation and is used for analysis. At the end of each scenario the collected degraded audio was subjected to analysis using the objective PESQ method which generates a MOS equivalent score between 1 (poor) and 5 (excellent). The work first evaluated, in preliminary tests, how much QoS of applications is affected by each factor and later their combination. To create the scenarios, the Core 4.8 network condition emulation tool was used. Finally, it could be concluded that the application SOMAapp application generally had better performance than Whatsapp, because, in the preliminary scenarios, in 06 of the 09 scenarios obtained a higher PESQ MOS scores. In scenarios with a lower grade, the difference was less than 0.5 scores. Another observation from the preliminary tests is that both were more affected by the jitter factor. In the evaluation scenarios, the application SOMAapp also presented better grades PESQ MOS, but presented greater grade variation, while whatsapp was more stable. Overall, out of 37 scenarios, in 91.0% of cases the SOMAapp application scored higher