gsm-network-simulator

Desktop app that simulates workings of a GSM network.

About

This repo showcases my GSM network simulation project I did as one of my Java class assignments.

How it works

It's a simple chain of communication, where messages traverse through layers of different network elements:

VBD > BTS > BSC > ... > BSC > VRD

where:

VBD - source cellphone.
BTS - short-range cell tower.
BSC - long-range cell tower.
VRD - receiver cellphone.

Key rules

The unit receiving the message is always picked randomly (except for the VRD).
Towers pass messages with random delay, for BTS its [500, 3000] ms, for BSC [1000, 5000] ms.
If every tower in a layer has a message load > 5, a new one spawns.
The number of BSC tower layers depends on the user, but will always be >= 1.
If a BSC layer gets deleted by the user, every BSC in that layer passes its messages further with no delay.
If the end-point BTS can't find the receiving VRD (it got deleted by the user) an exception gets raised.

User action

The user may:

Add a VBD device, change its message sending frequency, deactivate, or remove it.
Add/remove BSC tower layers, extending or reducing the overall message travel time accordingly.
Add/remove VRD devices, choose whether their messages received counter should reset periodically.

Technology

The main purpose of this project was to practise multithreading, polymorphism and abstract classes. It's built in the Swing framework, and emphasises on a clear division between the program's GUI and internal logic modules.