Presentation Of Communication SystemTopic:- Transmission mediaSubmitted to :- Sir Mohsin bhattiSubmitted by :- Muhammad Uzair Rasheed 2009-CPE-03 UCE&T BZU MULTAN
Transmission MediaThe means through which data is transformed fromone place to another is called transmission orcommunication media.Types Guided Media Twisted Pair Coaxial Cable Optical Fiber Unguided Media Radio waves Transmission Microwave Transmission Infrared Transmission Laser Transmission
Guided MediaGuided Media is that contain some conducting materialto carry data or signal. Many types of cable and wiresfall under this category. Each of them has its owncharacteristics like transmission speed, effects of noise.Guided media is also known as wired media. In this wewill use wires to send our data from one place to otherplace. Unguided MediaIt does not contain the signal in some physical conductoror metal. Rather, it transport electromagnetic signalthrough air. It is also known as wireless media. Becausein this we are not using any kind of cable.
Twisted PairPair of copper wires constitutes a single communicationlink . Twists minimize the effects of electromagneticinterference - 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 CableShielded, less susceptible to noise and attenuationthan 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 FiberCore: Thin strands of glass Cladding :Glass with different optical properties than core.Jacket: Plastic/Insulation
Unguided MediaRadio waves Transmission•The Radio waves have frequencies between 3khzand1Ghz•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.
Micro waves Transmission•Micro waves electromagnetic waves having frequencybetween 1 GHZ and 300 GHZ.•There are two types of micro waves datacommunication 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 300GHz to 400 THz are called IR waves or Infrared waves.•IR waves are used for short range communication anduse line of sight propagation.•Infrared waves cannot pass through solid objects, likewalls and be easily contained in a room.•They are cheap, easy to build and do not require anygovernment license to use them.
Laser Transmission•This type of transmission use thin laser to transfer dataup to few kilometers.•Laser beams are unidirectional, therefore this type oftransmission system use line of sight propagation.•In such a transmission system, a photo detector andlaser is set on both sender and receiver side.•Such a system offer very high band width at a very lowcost.•The major problem in this transmissionsystem is that laserbeams cannotPenetrate rain or thick fog.