110 likes | 351 Vues
DATA COMMUNICATION. Done by: Nandanie Gayadeen Carissa Edoo. Data Communication. What is transmission media? Wireless media, radio, satellite, Microwave, infrared:1. How they work ? 2. Where used? What is bandwidth? Data sources. What is Transmission Media?.
E N D
DATA COMMUNICATION Done by: Nandanie Gayadeen Carissa Edoo
Data Communication What is transmission media? Wireless media, radio, satellite, Microwave, infrared:1. How they work ? 2. Where used? What is bandwidth? Data sources
What is Transmission Media? • Just as humans can communicate through telephone wires or sound waves in the air, computers can communicate through cables, light and radio waves. Transmission Media enables computers to send and receive messages but it is not guaranteed that all of these messages would be understood.The most common type of media is copper cable. The most common types of copper cabling are twisted-pair and coaxial. Twisted-pair cabling used in a LAN is similar to the cabling used to connect your telephone to the wall outlet. Network coaxial cabling, on the other hand, is similar to the cable used to connect your television set to the cable TV outlet.
Wireless Media • What is wireless media? • Wireless media is the transmission of waves that takes place in the electromagnetic spectrum. The hertz (cycles per second) is used to express the carrier frequency of the data. Low frequency signals cannot carry a high bandwidth of date but can travel long distances through lots of obstacles, while high frequency signals can carry a high bandwidth of data but cannot travel for long distances through many obstacles.
Radio • A radio is the transmission of signals by modulation of electromagnetic waves with the frequencies below those of visible light. In radio broadcast, as in most electronic sound transmission, the microphone and the loudspeaker are critical pieces of equipment because they provide the link between sound waves and radio waves. The microphone converts sound waves into electrical signals and the loudspeaker converts electrical signals back into sound waves.
Satellite • A satellite is an object placed into orbit. There are many types of satellites and they are used for many purposes, such as broadcasting T.V, Weather forecasting, Earth observation and many more. • Some of the different types of satellites are : • Communication satellites: This type of satellite is most common and besides providing T.V programmes they also provide us with telephone, internet, information, and communication for ships at sea. The bandwidth of a satellite in 99 megabits per second or a million bits of data per second.
Microwave • It is a electromagnetic wave with wave lengths ranging from as long as one millimetre to as long as a metre. • Electromagnetic radiation beyond the frequency range of radio and television can be used to transport information. • Microwave transmission is usually point to point using directional antenna with a clear path between transmitter and receiver. • Microwave technology has applications in all three of the wireless networking scenarios: LAN, Extended LAN, and Mobile networking. • The bandwidth of a microwave is27MHz OR 3MHz to 30MHz.
Infrared • Infrared light is a form of electromagnetic waves and can be visible light or can be in the form of microwaves. • Infrared can be seen as red or violet in its visible form. Visible infrared waves are very short, about 750 mm in length. Longer infrared waves which are closest to microwaves are about 1mm in length. • Infrared transmission is mostly limited to one small area, for example, a room, with the transmitter pointed towards the receiver. The hardware does not require and antenna.
What is Bandwidth? • What is bandwidth? • Bandwidth is a rate of data transferred through bit rate measured in bits per second.
Sources of Information • Types of transmission media: http://dev.fyicenter.com/InterviewQuestions/Networking/What_are_the_types_of_Transmission_media_.html • What is transmission media: http://www.measureup.com/testobjects/ms_netess/5a671dd.htm • Wireless Media: http://www.comptechdoc.org/independent/networking/cert/netwireless.html