AuFi (Audio Fidelity) Technology

Objectives

Investigate sound based data transfer system for smartphone and integrate the methodology to communication app to demonstrate its functionality

Introduction

Sound is a vibration that travels through the air or solid medium. It is a longitude waveform that can propagate. Technology based on sound or acoustics are found in almost all aspects of modern society.

In recent days, the wireless communication technology has become an integral part of several types of communication devices as it allows users to communicate even from remote areas. Wi-Fi, WiMAX, Bluetooth are such technologies that uses in everyday life. The goal of this project is to research and develop a method to implement communication method using sound.

Au-Fi app is phone to phone data transferring app. Which uses its transferring method as sound. The app is mainly focus to overcome the challenges such as,

• Encoding and decoding data using frequencies
• Finding effective protocol to make reliable data transfer using sound spectrum
• Minimize the disturbances from sound when using the app

By using Au-Fi in smartphones in and around a building, the technology could enable cost effective and easy broadcasting features than a single Wi-Fi router. Drawbacks to the technology include the need for a silent area, difficulties with efficient and the requirement that range should be minimized.

Methodology

Let f(T1) and f(T2) are distinct frequencies (f(T1) > f(T2)) of the sound spectrum which can detect and provide by smartphone. If the present of the f(T1) denoted as “0” and  f(T2) denoted as “1” then binary model can be implemented to represent some data.
The app is targeting to implement this binary system  as communication method and investigate the protocols to do so.

Let transferring data to be digit 9 which should transfer to phone A to phone B. then The app encoding data into frequency by mapping bit code into f(T1) and f(T2). In this case It maps
1001   to   f(T2) f(T1) f(T1) f(T2)
Then the phone A uses its speaker to transfer the frequency by using a transfer protocol such as below,

T is constant time period which used to determine the existence of the bit and silent time period is used to distinct two bit from data confusions.

In the meantime Phone B is is set to receiving mode with the same app and it uses its microphone to listening to sound spectrum. If there is broadcast the app is guided to collect data and analyze using fourier transform and filtering methods.

The app is also guided to decode the data and present to the user or the GUI in android way manner. This part is also used to omit the noisy data and obtain reliable receiving.

Used Tool