Introduction to OPNET
Optimized Network Engineering Tools (OPNET) is a complete system design capable of simulating large communications networks with detailed protocol modeling and performance analysis. OPNET has been designed to provide a complete environment for the network model, which combines the advantages of the demanding graphics engineering workstations. OPNET tools in a tightly integrated system with the following principleFeatures
Data Collection Tools
• Domain Specific, hierarchical models, OPNET is specially designed for the development and analysis of communication networks and provides full details are not available in a simple resource-based simulation packages.
• Models of network hardware and software are structured hierarchically, so that an extensive re-use of models developed in different simulations. Graphical specification of the model - Where possible, the data are entered graphicallyEditors. These editors provide an efficient means to capture design through a coherent set of methods modems mouse-driven interface as menus and icons.
• Automatic generation of simulation - opening soon! reduces the effort for a simulation, providing an efficient event-driven simulation kernel, libraries and compilers, communications devices, take over the design specifications and automatically generates an executable simulation development. The largeSoftware development is usually associated with a simulated complex system is therefore drastically reduced.
• Analysis tools - debug design, analysis and trade-off analysis requires huge amounts of simulation results are interpreted by the technician. A set of analytical tools and an interactive debugger to offer sophisticated data reduction techniques, simulation results are easy to understand graphical summaries and monitor the behavior pattern in detail.
•Flexibility and detailed modeling - While much of the specific structural model of OPNET is done graphically, models and algorithms use a hybrid approach known as proto-c, which allows users to insert C code in a graph specified finite automaton.
The specification of the processes in C is an extensive library of support procedures, which makes it easier to offer a wide range of simulation services. Also indicated on the outside of the code of OPNETSystem can be connected to produce simulations in OPNET. Ability to fully integrate this general high-level language code provides the user with a high degree of flexibility in the construction of models at every level of detail.
OPNET can be used by networks of communication in many different application areas. Some examples of possible applications include local area networks, mobile packet radio networks, ISDN architecture, distributed sensors and control technology, networks and tactical networks.
ModelDomains
OPNET simulations on four separate domains of modeling called network nodes, process and network models Linkillustrates based on the definition of node models, process models to take back. In addition, models are used to characterize the connection links in the network domain. The design methodology for the simulation is typically created from the bottom to the top of the first users of process models and then builds models to integrate the node, and then buildsNetwork models are equipped with node models
The communication link.
Process Models in Proto-C language, which uses a graphical editor, given to capture the structure of the process in the form of a finite state machine (FSM). The FSM contains the logic of the process model in its states and transitions. Process models using a library of kernel procedures that support packet access, network variables, statistics, communication packages andother service programs of simulation.
The inclusion of links connecting domainallows personalized or customized simulation models in OPNET. The channels of communication between each pair is modeled as a transmission pipeline that provides flexibility in specifying the transfer of media between two nodes. Link templates are written in C and linked directly into the simulation.
The node domainconsists a series of modules that can be connected by arbitrarily complex node architectures together. TheProcessor modules and the run queue process models specified as finite state machines. The generator module produces packets according to user-specified stochastic probability density function. The transmitter and receiver modules are the interface for the connection-level modules, the packets transmitted between nodes.
In the network models are instantiated and domainnode each instance is independent attributes, including the identification and location assigned, and user-defined attributes.Within the network level editor can subnet objects, which provides an additional level of abstraction is also created. There are physical nodes connected wireless nodes, nodes and nodes in the mobile satellite network domain.
System design
OPNET system is a set of tools that are divided into three functional areas are: specification, simulation and analysis. The specification consists of five graphical editors that allow users to specify their design, which areNetwork Editor, Editor of the node, process editor, parameter editor, and editor of the sample. The simulation is the simulation tool and the simulation kernel. The analysis consists of the analysis tool that processes and presents graphically the results of the simulation and the filter editor to build the result of special processing filters. These three areas are supported by a continuous graphical window management system called Tool
Network Editor:
The instrument isbe used to specify network models, which consists of the subnet and node objects. The node objects are physical instantiation of the nodes in the models constructed node as well as publisher of the upper part of the modeling nodes subnet or on a global dimension for those airplane models, in which physical location is relevant places. Since the network editor provides the most comprehensive OPNET modeling, but also offers the necessary operations for all the other kids to connect to a specificsingle executable simulation.
Node Editor:
This tool is used to model node, the modules in a graph arbitrarily complex flow of information and the structural aspects of a particular class of communication nodes represent each configured to exist. Module Types Supported processors include general, generators, queues, transmitters and receivers and antennas.
Process Editor:
This tool is to specify process models, which provide tools,Algorithms, or decision-making processes in general. The data are based on the representations of the proto-c States finished machine language and include the names of states, transitions between states, the conditions for each transition, the actions that are executed when entering or leaving a coup or do variables of the transition, the time and the state and the formal characteristics of the process.
Parameter Editor:
This tool includes several different editing modes that will be used to specifyModel parameters that are more complex than simple numeric or string input. Types of parameters are functions of one or two independent variables that are specified graphically, and data tables that are specified using a spreadsheet like interface. The parameters created in the editor: The probability density function (PDF), packet formats, the interface information (LCI) formats, and also for OPNET / B Antenna Patterns and modulation function.
Champion Publisher:
This tool is used, Specify data collection, requests may be applied to a simulation run time to perform the execution of this model, the data of some detainees in an output file. A file created in the Sample Editor from a list of probes refers to a hierarchical statistical each module, a node, and a subnet.
Simulation tool:
The simulation tool provides an environment for the creation of one or more simulation runs, giving them input parameters and to guide theircollected data in output file name. The simulation tool uses a data table for the specific simulations and their parameters.
Analysis Tool:
This tool is used to simulate the experimental data, which were obtained using probes defined in the editor of the sample collected on a global or statistical reporting mechanisms to be analyzed. Data vectors can be represented with a variety of types of graphs. Scaler values from multiple simulation runs are obtained and presented together to respondSensitivity analysis for user-independent parameters of the model.
OPNET Modeler - A tool for network simulation