This research develops a computer simulation method for federating an Arena© port operations model and a VISSIM© roadway network operations model. The development of this method is inspired by the High Level Architecture (HLA) standard for federating simulations, and incorporates several elements of the HLA principles into its design. The federated simulation model is then tested using a time-lag experiment to demonstrate the presence of feedback loops between federated model components wherein changes to input parameters of one model during runtime can be shown to affect the operational performance of the other model. This experiment also demonstrates how several initial transient phase and steady state operating characteristics of the federated system can be determined from the federation output data. The results indicate that the method developed in this study is capable of capturing the dynamic interaction of two models in federated simulation. It is shown that feedback loops can exist between two models in federated simulation. Most notably, the federation output shows that increased traffic volume in the roadway network model influences the accumulation of containers in the port terminal queue of the port model. The federation output also shows that increased container volume leaving the port terminal model affects both port and road truck utilization, as well as the total number of port trucks in the roadway network model. Challenges and future directions for research in federating transportation-related simulations are also presented.

Federated approach for the distributed simulation of a network, is an alternative method that aims to combine existing simulation models and software together using a Run Time Infrastructure (RTI), rather than building the whole simulation from scratch. In this study, an approach that significantly reduces the inter-federate communication load in federated simulation of communication networks is proposed. Rather than communicating packet-level information among federates, characteristics of packet flows in individual federates are dynamically identified and communicated. Flow characterization is done with the Gaussian Mixtures Algorithm (GMA) using a Self Organizing Mixture Network (SOMN) technique. In simulations of a network partitioned into eight federates in space parallel manner, it is shown that significant speedups are achieved with the proposed approach without unduly compromising accuracy.