Analysis and Estimation of the Quality of Service of Group Communication Protocols

QoS (defined as a proper set of quantitative characteristics) analysis is a necessary step for the early verification and validation of an appropriate design, and for taking design decisions about the most rewarding choice, in relation with user requirements. In this paper, we describe an analytical approach for the evaluation of the QoS offered by a family of group communication protocols in a wireless environment, and use experimental data for feeding our models. Specific indicators have been defined and evaluated, which capture the main characteristics of the protocols and of the environment, focusing our attention on performance and dependability attributes. The main purpose of our analysis is to provide a fast, cost effective, and formally sound way to further analyze and understand the protocol behavior and its environment. The physical characteristics of the system have been considered and the models introduced in this paper account for the correlation among successive packet transmissions due to fading and users mobility.