Adaptive Maximums of Random Variables for Network Simulations

In order to enhance the precision of network simulations, the paper proposes an approach to adaptively decide the maximum of random variables that create the discrete probabilities to generate nodal traffic on simulated networks. In this paper, a statistical model is first suggested to manifest the bound of statistical errors. Then, according to the minimum probability that generates nodal traffic, a formula is proposed to decide the maximum. In the formula, a precision parameter is used to present the degree of simulative accuracy. Meanwhile, the maximum adaptively varies with the traffic distribution among nodes because the decision depends on the minimum probability generating nodal traffic. In order to verify the effect of the adaptive maximum on simulative precision, an optical network is introduced. After simulating the optical network, the theoretic average waiting time of nodes on the optical network is exploited to validate the exactness of the simulation. The proposed formula deciding the adaptive maximum can be generally exploited in the simulations of various networks. Based on the precision parameter K, a recursive procedure will be developed to automatically produce the adaptive maximum for network simulations in the future

Modeling and performance analysis of ATM LANs

Asynchronous Transfer Mode (ATM} is a method of data transmission using small fixed-length cells. This thesis presents a model of an ATM LAN which provides a realistic representation of data transmission over the system by explicitly modeling both the ATM network and the applications running over that network. Coloured timed Petri nets are used to create a compact model that is capable of representing a variety of different protocols at a high level of detail. The model is designed to allow easy reconfiguration or addition of detail at different levels of the system. Simulation is used to evaluate the performance of the model, and results are compared to actual data gathered from the Memorial University campus network