Data Communications Simulator

A full-stack application that simulates physical data transmission channels. It calculates signal attenuation, thermal noise levels, Signal-to-Noise Ratio (SNR), Nyquist theoretical bit rates, and Shannon Capacity limits in real-time.

This project uses a highly performant C binary for the mathematical physics engine, a Node.js Express backend API to pipe data, and a stunning Vite React frontend with an animated oscilloscope.

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Architecture Overview

1. C Core Engine (core/)
   • The math engine written in standard C.
   • sim.exe acts as a fast CLI program. It intakes physical inputs (Distance, Bandwidth, Medium, etc.) via arguments, performs attenuation/noise calculations based on Bolton's constant, and outputs results in JSON format.
2. Node.js API (backend/)
   • An Express.js REST API running on port 3000.
   • It listens for simulation requests on /simulate, spawns a child process to execute the sim.exe binary, and returns the JSON payload to the web client.
3. React Web UI (ui/)
   • A modern, glassmorphic dashboard built with Vite and React.
   • It debounces slider inputs, sends HTTP requests to the backend, and visualizes the degraded signal in real-time versus a clean reference signal using an animated SVG Oscilloscope.

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Getting Started

To run the full stack locally, you need two terminal windows: one for the backend API and one for the frontend UI.

1. Compile the C Engine

If you make changes to core/*.c, you must recompile the math engine for the backend to use:

gcc core/*.c -o sim -lm

2. Start the Backend API

The Express backend executes your C simulation and serves the data.

cd backend
npm install
node server.js

The API will start running on http://localhost:3000.

3. Start the Frontend UI

The React dashboard serves the interactive simulation controls.

cd ui
npm install
npm run dev

Open your browser to http://localhost:5173/ to view the UI.

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UI Features

• Interactive Telemetry: Slide parameters like distance, temperature, input power, bandwidth, and signal levels to dynamically stress-test the simulation.
• Physical Medium Selection: Toggle between Twisted Pair ($0.2 \text{ dB/km}$) and Fiber Optic ($0.05 \text{ dB/km}$) attenuation profiles.
• Oscilloscope Noise Extrapolator: Due to naturally minuscule thermal noise amplitudes, we've provided a visual slider to artificially amplify the noise jitter on the SVG oscilloscope so you can visually study signal degradation mechanics at varying SNRs.

Physics Equations Standardized

• Attenuation ($P_{RX}$): $P_0 \cdot 10^{-(\alpha \cdot d) / 10}$
• Thermal Noise ($N$): $k \cdot T \cdot B$
• Nyquist Bit Rate: $2 \cdot B \cdot \log_2(M)$
• Shannon Capacity: $B \cdot \log_2(1 + \text{SNR})$