Modeling Of The Basic Communication System With CPN Based On Hierarchical Thinking

There are many methods in modeling of communication systems, in which the object-oriented modeling and Petri Net modeling are the main modeling methods. UML, widely used in object-oriented modeling, is a semi-structured and semi-formal modeling language, so it can not provide rigorous formal reasoning and modeling checking, simulation execution and the quality of systems. Petri net is appropriate in concurrent and distributed systems modeling. Petri net is effective in rigorous analysis and verification because of its powerful mathematical theory, but along with the increasing complexity of the system, the models have many problems such as "state space explosion", reusability and maintainability. In order to solve the problems of the modeling, providing a right method to build communication system models is necessary.This paper first introduces the advantages and disadvantages and problems of object-oriented method and Petri net; then imports the concept of object-oriented and color set into the Petri net, and proposes a formal definition of the basic communication system based on its structural characteristics and hierarchical thinking, and gives the method of the basic communication system lamination and modeling; finally, the method is validated by an example of basic communication system.The method combines the advantages of both object-oriented technology and colored Petri nets. Compared with the basic Petri nets, colored Petri nets have the concept of color sets and arc expressions, which solve the problem of "state space explosion" effectively, and retain the analysis and verification methods of the basic Petri nets. Object-oriented models have excellent reusability and maintainability because of the characteristics of encapsulation and modularity. In addition, the method of lamination reduces the complexity of the large basic communication system models, and thus effectively reduces the system dependence intensity of the Petri net models. Therefore, the basic communication modeling method, which is based on hierarchical, utilizing color Petri net, combining object-oriented technology, can reduce the complexity of modeling, enhance the models verification, reusability and maintainability. It is a valuable modeling method.