Análisis e implementación en NS3 de un modelo de propagación difusivo para comunicaciones moleculares

Abstract

In this research, analysis and implementation of a MPD for MCs are performed in NS-3. The work is based on the IEEE 1906.1-2015 standard recommendation, which seeks to create a reference framework for MCs. The standard provides a simulation module in NS-3, which contains only the general structure components of MC and their interaction. The components mentioned are Message Carrier, Motion, Field, Perturbation and Specifity. The research is focused on four aspects: Modulation, Molecules movement, Inter Symbol Interference, and Demodulation. For modulation, the Perturbation component is modified, and the CSK modulation is implemented, which releases a certain number of molecules depending on the transmitted bit. Concerning the molecules movement, the Brownian mathematical model is implemented within the motion component. Also, two types of BM are considered: simple and drifting. The former refers to a free molecular motion, and the latter refers to a motion influenced by the direction of the fluid in which it moves. On the other hand, the fundamental element in the simulation is the medium, which manages the components motion and field. Within the medium the ISI is implemented. This interference considers molecules that remain moving in the medium and arrive at the receiver out of time. Finally, for the demodulation, the receiver has been modified to use the amplitude-based molecule detection technique. This technique demodulates the information depending on the number of molecules that have arrived at a determined time. Free BM, BM with drift, free BM bounded by the medium, and BM with drift bounded by the medium are considered. In addition to the modifications made, a data collection model was implemented to analyze the results, where the movement of the molecules is captured and, if they reach the receptor, the time is recorded. As a result, the pulse train of the concentration of molecules as a function of time at the receiver is obtained. Also, the delay time, the amplitude of the number of molecules, the pulse width, and the channel capacity as a function of distance at the receiver are evaluated. Besides, the obtained results are validated with an investigation performed in N3Sim. Finally, it is corroborated that the receiver’s concentration using the MPD implemented complies with the mathematical model established by Fick’s second law