Presentation2

Transmission of compressed video signal from PC to PC

through Microwave link.

Professor Sutapa Mukherjee. Ishan Aditya Debdyuti Banerjee Rohini Karmakar Abhisek Nag

¤ Communication ¤ PC to PC communication i) Using Lan ii) Using World Wide Web Net iii) Using Wan etc.

We are using :

Mic ro wa ve Li nk

The advantages of Microwaves are: 1.Frequency range is high(1Ghz-100Ghz) 2.Increased no. of channels with high SNR. 3.Can move freely through the ionized layer of the atmosphere. 4. Line of sight communication & Relatively smaller size antenna are used 5. Reliable & require less maintainance.

Project Sub modules : ¤ Done so far : Study : 1.Study of relevant software part. 2. Study of RS-232 port & DB-9 connector. 3. Study of Klystron source. 4. Study of various image compression techniques.

Procedure Part: 1.Transmission & reception of signal generated by a function generator over a microwave link. 2.Testing the data signals coming from a computer & sending it over microwave link. 3.Testing of data at the receiving terminal of the microwave link.

Yet to be done : 1. Testing of the retrieved data at the receiver end pc & pattern matching with the sent data. 2. Sending & receiving of compressed signal from one PC to another over a microwave. 3. Sending &receiving of compressed video signal from one PC to another over a Microwave link.

Study of Software part :

Study of RS-232 & DB-9 connector : DB-9 connector

Pin description

Null Modem :

Abbreviat ion

Full Name

Function

TD

Transmit Data

Serial Data Output (TXD)

RD

Receive Data

Serial Data Input (RXD)

CTS

Clear to Send

This line indicates that the Modem is ready to exchange data.

DCD

Data Carrier Detect

When the modem detects a "Carrier" from the modem at the other end of the phone line, this Line becomes active.

DSR

Data Set Ready

This tells the UART that the modem is ready to establish a link.

DTR

Data Terminal Ready

This is the opposite to DSR. This tells the Modem that the UART is ready to link.

RTS

Request To Send

This line informs the Modem that the UART is ready to exchange data.

RI

Ring Indicator

Goes active when modem detects a ringing signal from the PSTN.

Study of Klystron : Two cavity Klystron oscillator :

Image compression techniques • JPEG • It is used to compress natural images or photographs. • It can display 16 million colours. • It can achieve a compression of 20:1 without visible loss.It compresses an image having 24 bits per pixel to 2 bits per pixel

• GIF • It is used to compress line drawings on images with few colors. • It can display 256 colours • It can achieve a compression of 5:1.It compresses an image having 24 bits per pixel to 8 bits per pixel.

Transmission & reception of signal generated by a function generator:

Microwave setup made for the experiment

Klystron Oscillator

Output waveform seen on the oscilloscope

Transmission & reception of the signals (data) coming from a computer Data coming from computer

Data insertion at Klystron as External modulation signal

Transmition of data through Microwave link

Connecting oscilloscope directly with the computer & the receiving Horn antenna

60MHz Oscilloscope

Output waveform seen on the screen of the oscilloscope

Output saved in a floppy

Hurdles faced Hardware problems Handshaking signal problems Soldering problems Function generator problems Concept of serial port Compatibility problems Frequency modulation

Further works • • • • • • • •

USB Real time video conferencing Voltage level problem Db25 Secuirity check Compression techniques Synchronization of Tx and Rx (UART) Use of buffer.

Special thanks to : Professor B. Som. S