In this paper the conservative Chandy-Misra parallel simulation algorithm is discussed. The basic algorithm is improved by using null message cancellation, simulation loop optimization and multicasting techniques. The algorithms are used for the simulation of a GSM mobile network application in a distributed workstation environment, Diworse. In the simulation results, special attention is paid to the execution time and the number of messages transmitted during the simulation. Results from several workstation configurations and different algorithms are compared. Results indicate that the algorithm with simulation loop optimization reduces the number of transmitted messages efficiently making the use of the distributed workstation environment profitable.