Скачать или смотреть Efficiently Generate Poisson Traffic with OMNeT+ + : Accessing Module Parameters and Using For Loops

Discover how to effectively access parameters across different modules in OMNeT+ + and implement for loops in your initialization files for effective simulation of Poisson traffic.
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Efficiently Generate Poisson Traffic with OMNeT+ + : Accessing Module Parameters and Using For Loops

When working with simulation frameworks like OMNeT+ + , you may encounter the challenge of configuring parameters across multiple modules efficiently. A particular scenario arises when trying to simulate Poisson arrivals of traffic while systematically setting start times for applications within clients. If you have 100 clients each featuring 20 applications, managing these settings can quickly become cumbersome, especially when aiming for a generic, scalable solution.

The Problem

The primary issue here is twofold:

You need to access parameters from different modules to set them as inputs for other modules.

You want to implement a for loop to simplify the repetitive task of defining multiple parameters.

For example, you want to initialize the start time of the first application for the first client. Following that, the start time for subsequent applications should rely on the previous application's start time, each calculated based on a specified inter-arrival time (iat). Hardcoding each parameter would result in a large file that's unwieldy to manage.

Example of Desired Setup

Your setup might look like this in the .ini file:

[[See Video to Reveal this Text or Code Snippet]]

Unfortunately, due to the limitations of INI files in OMNeT+ + , directly referencing another module's parameters in this way is not feasible.

Understanding INI File Limitations

INI files in OMNeT+ + serve as declarative constructs rather than procedural ones. This means that:

Each line in an INI file matches a module's initialization parameters based on the left side of the equals sign.

The right side specifies the parameter's value corresponding to the relevant module path.

The order of these matches can be unpredictable, which prevents referencing parameters from other modules effectively.

This means you cannot use constructs like loops within an INI file since they do not support cross-references or procedural operation.

Proposed Solutions

1. Use the initialize() Method

You can perform these initializations within the initialize() method of your module by writing C+ + code:

Access any other module's parameter using the appropriate C+ + APIs.

This way, you gain complete control over the initialization order and can easily implement loops.

Example in C+ + :

[[See Video to Reveal this Text or Code Snippet]]

2. Create a Configurator Module

If modifying existing applications is not ideal, consider creating a separate configurator module. This module will handle procedural initialization, iterating through your applications to set their parameters as needed. This approach is not uncommon in INET frameworks where computed initialization data is required.

3. Future Scripting Options

Though not currently supported in OMNeT+ + , consider future developments where you could set up simulation configurations using a scripting language, like Python. Such capabilities may eventually ease these limitations further.

Conclusion

To summarize, direct referencing parameters across modules in OMNeT+ + INI files is not feasible due to their static and declarative nature. Instead, you should implement your initialization logic within the initialize() method using C+ + to effectively set parameters dynamically or build a configurator to assist in that process. By adopting these strategies, you not only retain clarity in your simulation setup but also enhance its scalability, making handling large simulations manageable.

Embrace these methods, and you’ll streamline your process of managing