Transmission Media : Data Communication and Computer Networks Asst. Prof. Chaiporn Jaikaeo, Ph.D. Computer Engineering Department Kasetsart University, Bangkok, Thailand Adapted from lecture slides by Behrouz A. Forouzan © The McGraw-Hill Companies, Inc. All rights reserved

2 Physical Layer

3 Classes of Transmission Media

4 Guided Media Provide a conduit from one device to another Provide a conduit from one device to another Include Include twisted-pair cables twisted-pair cables coaxial cables coaxial cables fiber-optic cables fiber-optic cables

5 Twisted-Pair Cable

6 UTP – Unshielded Twisted PairSTP –Shielded Twisted Pair UTP and STP Cables

7 Categories of UTP/STP Cables

8 CategoryBandwidthDigital/AnalogUse 1 very low AnalogTelephone 2 < 2 MHz < 2 MHzAnalog/digital 4Mbps token ring 3 16 MHz 16 MHzDigital Mbps Ethernet 4 20 MHz 20 MHzDigital 16 Mbps token ring MHz 100 MHzDigital 100 – 1000 Mbps Ethernet 5E 100 MHz Digital 100 – 1000 Mbps Ethernet MHz 250 MHzDigital 1 – 10 Gbps Ethernet 6A 500 MHz Digital 1 – 10 Gbps Ethernet MHz 600 MHzDigital 10 Gbps Ethernet 7A 1000 MHz Digital Gbps Ethernet

9 RJ – Registered Jack UTP Connectors

10 UTP Performance

11 Coaxial Cable

12 RG – Radio Government Categories of Coaxial Cables

13 BNC Connectors Bayonet Network Connector Bayonet Network Connector aka. Bayonet Neil-Concelman aka. Bayonet Neil-Concelman Used with coaxial cables Used with coaxial cables

14 Performance of Coaxial Cables

15 Optical Fiber Based on physics of light Based on physics of light

16 Optical Fiber

17 Propagation Modes

18 Fiber Types

19 Fiber Construction

20 Fiber-Optic Cable Connectors

21 Optical Fiber Performance

22 Unguided Media: Wireless Transport electromagnetic waves without using a physical conductor Transport electromagnetic waves without using a physical conductor Radio Waves Radio Waves Microwaves Microwaves Infrared Infrared Often referred to as wireless communication Often referred to as wireless communication

23 Electromagnetic Spectrum

24 Propagation Methods

25 Bands

26 Antennas Omni-directional AntennaUnidirectional Antennas

27 Wireless Transmission Waves used for multicast/broadcast communications, such as radio and television used for unicast communication such as cellular telephones, satellite networks, and wireless LANs used for short-range communication in a closed area using line-of-sight propagation