1. 7.1 Chapter 7 Transmission Media Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. 7.2 Figure 7.1 Transmission medium and physical layer

3. 7.3 Figure 7.2 Classes of transmission media

4. 7.4 7-1 GUIDED MEDIA Guided media, which are those that provide a conduit from one device to another, include twisted-pair cable, coaxial cable, and fiber-optic cable. Twisted-Pair Cable Coaxial Cable Fiber-Optic Cable Topics discussed in this section:

5. 7.5 Figure 7.3 Twisted-pair cable

6. 7.6 Figure 7.4 UTP and STP cables

7. 7.7 Table 7.1 Categories of unshielded twisted-pair cables

8. 7.8 Figure 7.5 UTP connector

9. 7.9 Figure 7.6 UTP performance

10. 10 Twisted Pair Cable (Pros & Cons) pro: easy to understand low cost most widely used medium Cons: prone to electromagnetic interference in power plants, airport buildings, military facilities, cars… Note: In-building networks at our university are almost all twisted pair

11. 7.11 Figure 7.7 Coaxial cable

12. 7.12 Table 7.2 Categories of coaxial cables

13. 7.13 Figure 7.8 BNC connectors

14. 7.14 Figure 7.9 Coaxial cable performance

15. 7.15 Figure 7.10 Bending of light ray

16. 7.16 Figure 7.11 Optical fiber

17. 7.17 Figure 7.12 Propagation modes

18. 7.18 Figure 7.13 Modes

19. 7.19 Table 7.3 Fiber types

20. 7.20 Figure 7.15 Fiber-optic cable connectors

21. 7.21 Figure 7.16 Optical fiber performance

22. Optical Fiber (Pros & Cons) Pros: Low attenuation Large bandwidth Light Weight Immunity to electromagnetic interference Cons: Relatively “new” technology “Expensive” Unidirectional light propagation

23. 7.23 7-2 UNGUIDED MEDIA: WIRELESS Unguided media transport electromagnetic waves without using a physical conductor. This type of communication is often referred to as wireless communication. Radio Waves Microwaves Infrared Topics discussed in this section:

24. 7.24 Figure 7.17 Electromagnetic spectrum for wireless communication

25. 7.25 Figure 7.18 Propagation methods

26. 7.26 Table 7.4 Bands

27. 7.27 Figure 7.19 Wireless transmission waves

28. 7.28 Figure 7.20 Omnidirectional antenna

29. 7.29 Radio waves are used for multicast communications, such as radio and television, and paging systems. Note

30. 7.30 Figure 7.21 Unidirectional antennas

31. 7.31 Microwaves are used for unicast communication such as cellular telephones, satellite networks, and wireless LANs. Note

32. 7.32 Infrared signals can be used for short- range communication in a closed area using line-of-sight propagation. Note