Visual and persistent co-design modeling for network systems

Network systems are challenging to model because of the complexity inherent in the software and hardware designs as well as the numerous ways that they may be synthesized. A desired goal towards describing computer network systems is: visual and persistent modeling of combined software and hardware components. Furthermore, the co-design modeling approach is poised to provide advanced capabilities to support separate and combined specifications of software and hardware layers of network systems. The Distributed Object Computing (DOC) approach offers an abstraction for modeling any network system in terms of logical specification of software and hardware components and the mappings of the former to the latter. The abstraction defines software (Distributed Cooperative Objects (DCO)), hardware (Loosely Coupled Network (LCN)), and Object System Mapping (OSM) models. These models can be described and simulated in DEVS/DOC—a DEVS-based environment for simulating DOC models. However, neither DOC nor DEVS offers visual and persistent model concepts and methods. In contrast, Scalable Entity Structure Modeler (SESM) framework supports a unified logical, visual, and persistence component-based model development for specifying families of complex system designs, but it lacks direct support for co-design. Considering the limitations of DEVS/DOC, SESM, and other modeling approaches, this dissertation develops an approach called SESM/DOC where logical co-design model specifications can be developed visually and stored in relational databases. This approach introduces visual and persistent co-design capabilities for describing a family of logical models for network systems. The SESM/DOC has been devised to support consistent logical, visual, and persistent modeling for the DCO, LCN, and OSM models. A prototype has been developed (i) to support separate visual working sections for software and hardware modeling and their synthesis, (ii) to store logical co-design models, and (iii) to automatically generate partial equivalent DEVS/DOC models. For the purposes of demonstration, an example of search engine systems is considered. The example is modeled in SESM/DOC and simulated in DEVS/DOC. The role of the proposed co-design modeling approach and its application for development of network system designs is examined and select future research directions are briefly described.