Enhancing QoS/QoE in multimedia networks

In a multimedia context, QoS (Quality of Service) is a measure of success. It represents the guarantee of successfully delivering packets, without delaying or dropping any, therefore, the guarantee of providing high quality experience for end-users. Depending on the content being delivered, there exist various parameters which need to be considered when designing QoS architectures, such as latency, jitter, bandwidth and packet loss. There is a direct and high impact of such parameters on voice quality, video streaming, data traffic etc. On the other hand, high-performance networks are required to support different traffic types, alternating from continuous data streams for real-time communication to burst traffic for best-effort communication. The traffic on high-performance networks can be divided into four categories: Constant Bit Rate, Variable Bit Rate, Available Bit Rate and Unspecified Bit Rate, according to the service requirements of source applications and to the arrival characteristics. The aim of the research work presented in this paper is to identify the most appropriate QoS-related techniques to be applied in order to provide qualitative services and to ensure the efficiency of resource consumption, under the constraints imposed by each traffic type. The research results are based on performance measurements conducted within our Competence Center for Network Management, taking into consideration various traffic types, queuing mechanisms and resource reservation protocols.