Aplicaçãao da Suavização de Tráfego para Melhoria da Qualidade de Experiência em Sistemas IPTV

The transmission of real-time multimedia streams requires service guarantees, such as limited packet loss, minimum bandwidth and limited delay and jitter, in order to deliver a good quality of experience (QoE) for viewers. The spatial and temporal redundancy of videos is explored by coding algorithms, reducing the amount of information necessary to represent the images. As a consequence, multimedia traffic commonly presents variable bit rate behavior and self-similar characteristics. Although the reduction in bandwidth requirements is highly desirable, the burstiness of traffic leads to problems in network design and performance prediction. Particularly in the case of video streaming, the self similar behavior tends to increase the average packet delay and jitter, and increase the probability of packet loss. Even a low level of packet loss could severely affect the viewer QoE. In this paper, we propose the use of traffic shaping to reduce the burstiness of video traffic. We choose to use the token bucket algorithm due its simplicity and its wide utilization in computer networks. The main contribution of the paper is the method to configure the parameters of token bucket using the video characteristics. The efficiency of proposed method is demonstrated through computer simulations and the results indicate that the use of proposed method effectively improves the QoE.