Presentation Of Communication System

Topic:- Transmission media

Submitted to :- Sir Mohsin bhatti

Submitted by :- Muhammad Uzair Rasheed

2009-CPE-03UCE&T BZU MULTAN

Transmission MediaThe means through which data is transformed from one place to another is called transmission or communication media.Types Guided Media Twisted Pair Coaxial Cable Optical Fiber Unguided Media Radio waves Transmission Microwave Transmission Infrared Transmission Laser Transmission

Guided Media

Guided Media is that contain some conducting material to carry data or signal. Many types of cable and wires fall under this category. Each of them has its own characteristics like transmission speed, effects of noise.Guided media is also known as wired media. In this we will use wires to send our data from one place to other place. Unguided Media

It does not contain the signal in some physical conductor or metal. Rather, it transport electromagnetic signal through air. It is also known as wireless media. Because in this we are not using any kind of cable.

Twisted Pair Coaxial cable Optical fiber

Frequency

1Khz 1Mhz 1Ghz 1Thz 1000Thz

TwistedPair

CoaxFiberOptics

Guided Transmission Media

Twisted Pair

Pair of copper wires constitutes a single communication link . Twists minimize the effects of electromagnetic interference

- emit less energy- less susceptible to energy

Unshielded and Shielded TPUnshielded Twisted Pair (UTP)

Ordinary telephone wire Cheapest Easiest to install Suffers from external EM interference

Shielded Twisted Pair (STP) Metal braid or sheathing that reduces

interference More expensive Harder to handle (thick, heavy)

Coaxial Cable

Shielded, less susceptible to noise and attenuation than Twisted Pair.

Coaxial Cable Applications

Most versatile medium Television distribution

Cable TV Long distance telephone transmission

Can carry 10,000 voice calls simultaneously Being replaced by fiber optic

Short distance computer systems links Local area networks

More expensive than twisted pair, not as popular for LANs

Optical Fiber

Core: Thin strands of glass Cladding :Glass with different optical properties than core.Jacket: Plastic/Insulation

Radio waves Transmission

•The Radio waves have frequencies between 3khz and1Ghz•Radio waves can penetrate buildings easily, so that are widely use for communication both indoors outdoors.•They also absorbed by rains•At high frequency, radio wave tends to travel in straight line and bounces off the obstacles.

Unguided Media

Micro waves Transmission

•Micro waves electromagnetic waves having frequency between 1 GHZ and 300 GHZ.•There are two types of micro waves data communication system :• terrestrial and satellite•Micro waves are widely used for one to one communication between sender and receiver, cellular phone, satellite networks and in wireless LANs.

Infrared Waves•Electromagnetic waves having frequencies from 300 GHz to 400 THz are called IR waves or Infrared waves.•IR waves are used for short range communication and use line of sight propagation.•Infrared waves cannot pass through solid objects, like walls and be easily contained in a room.•They are cheap, easy to build and do not require any government license to use them.

Laser Transmission•This type of transmission use thin laser to transfer data up to few kilometers.•Laser beams are unidirectional, therefore this type of transmission system use line of sight propagation.•In such a transmission system, a photo detector and laser is set on both sender and receiver side.•Such a system offer very high band width at a very low cost.•The major problem in this transmission system is that laserbeams cannot Penetrate rain or thick fog.