Analysis of Stochastic Service Guarantees in Communication Networks: A Server Model

Many communication networks such as wireless networks only provide stochastic service guarantees. For analyzing stochastic service guarantees, research effort has been made in the past few years to develop stochastic network calculus, a probabilistic version of (min, +) deterministic network calculus. However, many challenges have made the development difficult. Some of them are closely related to server modeling, which include output characterization, concatenation property, stochastic backlog guarantee, stochastic delay guarantee, and per-flow service under aggregation. In this paper, we propose a server model, called stochastic service curve to facilitate stochastic service guarantee analysis. We show that with the concept of stochastic service curve, these challenges can be well addressed. In addition, we introduce strict stochastic server to help find the stochastic service curve of a stochastic server, which characterizes the service of the server by two stochastic processes: an ideal service process and an impairment process.