1. INTRODUCTION

Communication may be considered as the art of expressing oneself coherently. In

the present electronic era, communication has taken the definition: the technique or

process of exchange of meaningful data among entities. With technology as the catalyst,

communication has burgeoned over the last couple of decades. The notion of a physical

medium for communication is fast vanishing. Technology has it that today

communication is possible without actual physical connection between devices. This

project explores one such technology namely, optical communication.

Infrared rays are an efficient means of communication and data transfer. The

merits of this technique are that it does not require physical connection between devices,

it is cost effective and it is simple and easy to implement.

1.1 OBJECTIVE

This project involves setting an optical communication link between two

computers and transmitting and receiving data. Each computer has a transmitter and

receiver attached to it and is thus capable of transmitting as well as receiving data. The

data to be transferred is first collected. The compression algorithm is performed on the

data. Then the encryption algorithm is used to encrypt the data to provide a basic level of

security. Finally the data are converted to infrared rays and then transferred

1.2 SYSTEM ANALYSIS

1.2.1 Why Infrared?

The main idea behind this project is to implement communication in a LAN

system efficiently. This communication can be established using

Radio Waves

Ultrasonic Waves

Laser Beam

Infrared Beam

Radio Waves travel in all the directions. So there is no privacy and security of

data. Special licenses are also required from government in order to use these waves for

transmission. Ultrasonic waves are directional and travel only to a limited distance. Laser

beam is highly directional. So alignment poses a very great problem. Laser diodes are

expensive. Laser beam is very hazardous to human beings. The problems mentioned

above are not encountered in case of Infrared beam.

1.2.2 How is the system ‘Secure’?

Since we are using a wireless system here, security of the data transmitted is of

utmost importance as any other external infrared device would be able to pick up the

optical pulses and demodulate it to get the message. Encryption plays a major role in data

privacy, and is used in this system to ensure security.

1.2.3 How fast is the File transfer?

The systems are connected through the serial communication port where the baud

rate can be set at 1200, 2400, 4800 or 9600, which indicates the bits per second transfer

rate. To enhance performance, we compress the file to be transferred, thereby reducing

transmission time.

2.0 PROBLEM DEFINITION AND METHODOLOGY

2.1 DEFINITION

This project aims to design wireless communication between two

computer systems for the transfer of data. The project must have the following

features.

1. The data transfer must be secured and the transmission should be fast.

2. The data transfer must be wireless.

2.2 METHODOLOGY

The development of the project is as follows:

1. At the transmitter we select the file to be transferred.

2. The destination of the file is also chosen on the receiver machine.

3. The encryption key is entered.

4. The file on being encrypted and compressed is then transferred to the receiver

machine using infrared rays.

5. At the receiver side the file to be received is chosen.

6. The reverse process then occurs.

7. The file on decryption and decompression is available to the receiver for use.