1 Transmission Media Lesson 04 NETS2150/2850. 2 Lesson Outline Wired or guided Media –Electromagnetics waves are guided along a solid medium Wireless.
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Presentation on theme: "1 Transmission Media Lesson 04 NETS2150/2850. 2 Lesson Outline Wired or guided Media –Electromagnetics waves are guided along a solid medium Wireless."— Presentation transcript:
2 Lesson Outline Wired or guided Media –Electromagnetics waves are guided along a solid medium Wireless or unguided media –Transmission occurs through atmosphere, outer space or water Understand media characteristics and typical applications
17 Optical Fibre - Benefits Great for “ noisy ” environments! Tremendous bandwidth –Data rates of hundreds of Gbps Smaller size & weight Lower attenuation –Greater amplifier spacing –40-60 km at least before amplification required for SMF Used in backbone and high traffic inter-city or inter continent links (submarine cables - undersea)
20 Wireless Transmission 30MHz to 1GHz –Suitable for Omnidirectional –Broadcast radio 2GHz to 40GHz –Microwave range –Highly directional –Point to point 3 x 10 11 to 2 x 10 14 Hz –Infrared range –Used within confined areas
21 Broadcast Radio Omnidirectional FM radio UHF and VHF television Requires line of sight
26 Satellite Microwave Satellite is a relay station It receives on one frequency (uplink), amplifies or repeats signal and transmits on another frequency (downlink) Requires geo-stationary orbit –Height of 35,863 km Applications: –Television live cast –Long distance telephone –Private business networks
30 Infrared Line of sight (or reflection) Shirt-range communications Blocked by walls e.g. TV remote control, infrared port on printers, laptops, mobile phones, PDAs etc.
31 Summary Guide Media –Twisted pair, Coaxial cable, Optical fibre Unguided or wireless media –Uses antenna as transmitter and receiver (transceiver) –Terrestrial microwave, satellite microwave, Broadcast radio, Infrared Characteristics and quality determined by medium and signal For guided transmission, the medium is more important For unguided, the bandwidth produced by the antenna is more important