1Steps in Simulation StudyTELCOM 2120 Network PerformanceJoseph KabaraTelecommunications ProgramUniversity of PittsburghSpring 2008, notes6TELCOM 2120: Network Performance2Designing Simulation Studies•Types of simulation software– general purpose – event scheduled simulation language – process oriented simulation language– application oriented simulator. •The basic steps in a simulation study the same regardless what type of software used•Begin with basic problem formulation –independent of software!Spring 2008, notes6TELCOM 2120: Network Performance3A Simulation StudyYesEndStartResults statistically useful?NoNoResults sufficiently detailed?Choosing input andrunning simulationsSystem results accurate?Defining input and outputSpecifying the system modelNoChoosing aspectsto be modeledUnderstanding your goals for the simulationUnderstanding the system
has intentionally blurred sections.
Sign up to view the full version.
2Spring 2008, notes6TELCOM 2120: Network Performance4Essential Simulation Steps•Problem Formulation•Data Acquisition/Model Specification•Model Building•Model Translation• Verification• Validation•Design of Experiments•Output Analysis• DocumentationSpring 2008, notes6TELCOM 2120: Network Performance5Problem Formulation•Define clear problem statements, objectives, scopes–Bad:to study the performance of system X.–Better:to study the performance metric M of system X under factors A, B, C, D. –Bad:to study if system X is better than system Y.–Better:Compare systems X and Y with respect to performance metric M1, M2.•Measurable and specific goals.•Must consider cost, time frame, required resources.Spring 2008, notes6TELCOM 2120: Network Performance6Data Acquisition/Model Specification•Collect input data–Distributions of interarrival time–Input traffic model–Packet size distribution•Specify level of details–Too much detail ⇒more development time, more bugs, more execution time.–Too simplified ⇒less accurate. –Must capture essential features.•Ex: Queueing node with background traffic.–Generate 100 background traffic flows.–Or Generate a single aggregate flow to represent 100 flows.