A New Approach for Accurate Modelling of Medium Access Control（MAC）Protocols

A New Approach for Accurate Modelling of Medium access Control (Mac) protocols Presenter: moshe zukerman ARC Centre for ultra broadband information networks EEE Dept The University of melbourne Presented at EE Dept, City University of Hong Kong, 11 April, 2002 Credit: Chuan Foh (eee, melbourne) C UBIN THE UNIVERSITY OF MELBOURNE

A New Approach for Accurate Modelling of Medium Access Control (MAC) Protocols Presenter: Moshe Zukerman ARC Centre for Ultra Broadband Information Networks EEE Dept., The University of Melbourne Presented at EE Dept., City University of Hong Kong, 11 April, 2002 Credit: Chuan Foh (EEE, Melbourne)

OUTLINE The big picture 2. Classical performance models 3. Ethernet 4.IEEE802.3 5. How can we get performance statistics for a complicated protocol 6. Breaking the problem into two: saturation and SSQ fed by correlated SRD Markovian trafic 7. Numerical results

1. The big picture 2. Classical performance models 3. Ethernet 4. IEEE 802.3 5. How can we get performance statistics for a complicated protocol 6. Breaking the problem into two: Saturation and SSQ fed by correlated SRD Markovian traffic 7. Numerical results OUTLINE

The Big Picture

The Big Picture

Link and Network Design and dimensioning Traffic Performance Traffic Modelling Evaluation Prediction Traffic Queueing Simulations and Measurements Theory Fast Simulations Formulae in Numerical Closed Form Solutions

Traffic Modelling Queueing Theory Performance Evaluation Simulations and Fast Simulations Numerical Solutions Formulae in Closed Form Traffic Measurements Link and Network Design and Dimensioning Traffic Prediction

Research in performance evaluation 1. Exact analytical results(models) 2. Exact numerical results(models) approximations 4. Simulations(slow and fast 5. Experiments 6. Testbeds 7. deployment and measurements 8.Typically, 4-7 validate 1-3

Research in Performance Evaluation 1.Exact analytical results (models) 2.Exact numerical results (models) 3. Approximations 4. Simulations (slow and fast) 5.Experiments 6.Testbeds 7. Deployment and measurements 8.Typically, 4-7 validate 1-3

Classical Performance models Poisson traffic model Many simplified assumptions on System/protocol operation Inaccurate results

Classical Performance Models Poisson Traffic Model Many simplified assumptions on System/protocol operation Inaccurate results

We want Realistic Traffic Model No simplified assumptions on System/protocol operation accurate results

We want Realistic Traffic Model No simplified assumptions on System/protocol operation Accurate results

Example 1: Ethernet The ethernet mac protocol (1) Carrier Sensed Multiple Access with Collision Detection(CSMA/CD) (2 The Binary Exponential Backoff (BEB) Algorithm

Example 1: Ethernet The Ethernet MAC protocol: (1) Carrier Sensed Multiple Access with Collision Detection (CSMA/CD) (2) The Binary Exponential Backoff (BEB) Algorithm

Ethernet C E G time C D E FG The big bang ofe. f g D time E F G

Ethernet D time F G The Big Bang of E, F & G E C D E F G C D E F G time

Detailed Analysis LAN traffic Served CSMA/CD packets BEB collided packets Ethernet or IEEE 802.3

Detailed Analysis CSMA/CD BEB collided packets LAN traffic Served packets Ethernet -or - IEEE 802.3