Reducing the Number of Logical Channels in the Chandy-misra Algorithm

In this paper the logical process structure of the Chandy-Misra parallel simulation algorithm has been studied. The excessive synchronization caused by the algorithm is avoided by minimizing the number of connections between logical processes. The amount of connections are reduced by restricting the direct communication of the logical processes to their neighborhoods. Two methods, message path and broadcast messages, are proposed to solve the communication between non-connected logical processes. Simulation experiments are carried out in a previously implemented distributed simulation environment, Diworse. A GSM network is used as a simulation application and carrier per interference (C/I) values for GSM channels are used for measuring the correctness of the proposed methods. Execution time of the simulation and C/I errors are measured in order to find out the effect of connection reduction. The results indicate that both the broadcast message and message path method enable faster simulation. In the GSM application the broadcast method has a negligible distorting effect to the simulation results while the message path method shows stronger event distortion.