Queuing Systems

Code 3.5.3248.6
Semester 6th
Flow D - Telecommunication Systems and Computer Networks
Category Obligatory (main flow)
Credits 6
Class Hours - Lab Hours 3 - 1
Lecturers Symeon Papavassiliou, Eleni Stai, Maria Grammatikou (T & R Associates), Irene Kilanioti (T & R Associates)
Links Helios, Course's Website
Web Platform Class 1: Webex


The course aims at introducing students to methodologies in modeling and performance evaluation for Internet based communication networks and computer systems. The emphasis is on the analysis of such systems as simple queuing models, complemented by simulation techniques. Yearly updated On-line Lectures (synchronized video/audio and transparencies) are accessed via the Network Management & Optimal Design Laboratory (NETMODE) web site - www.netmode.ece.ntua.gr. Topics covered include:

  • Overview of probability theory with emphasis on memoryless probability distributions (Poisson and exponential distributions)
  • Definitions of Markov stochastic processes, ergodicity
  • Definitions and basic models of queuing systems. Arrival& departure processes, state definition, steady-state behavior, steady-state probabilities, utilization, average queue size and delay, Little’s formula, throughput, blocking probability
  • Birth – death processes and applications in simple Markov queuing systems. M/M/1, M/M/1/K, M/M/N, M/M/N/N, state dependent queues
  • Open and closed networks of queues. Product form state probabilities, Burke’s theorem, Jackson’s theorem, Gordon/Newell theorem, Buzen’s algorithm
  • Introduction to M/G/1 queues, Pollaczeck–Khinchin formulae
  • Applications in performance evaluation of data networks, telephone networks and computer systems