1. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter Three Data Communication Concepts

2. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. A typical communication link between two LANs Figure 3.1

3. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The periodic sine wave is a fundamental analog signal Figure 3.2

4. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Concept of phase shifts relative to time zero Figure 3.3

5. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Amplitude, period, and bit duration of two binary waveforms Figure 3.4

6. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Amplifiers compensate for energy losses along a channel Figure 3.5

7. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Electrical or optical power levels of a signal at points 1 and 2 Figure 3.6

8. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Attenuation and amplification in a transmission path Figure 3.7

9. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Analog and digital signal representations Figure 3.8

10. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Digitization of analog waveforms Figure 3.9

11. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Typical AM, FM, and PM waveforms Figure 3.10

12. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Constellation or phase-state diagrams for QPSK and 8-PSK Figure 3.11

13. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Two possible constellations for 16-QAM Figure 3.12

14. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Examples of several commonly used line codes Figure 3.13

15. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Measurement of the length of an error burst Figure 3.14

16. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The basic procedure for the CRC technique Figure 3.15

17. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Two different procedures for finding the CRC Figure 3.16

18. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Example of the stop-and-wait flow control method Figure 3.17

19. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Concept of the sliding-window protocol operation Figure 3.18

20. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Example of frame retransmission using go-back-N ARQ Figure 3.19

21. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Structure of an optical fiber waveguide Figure 3.20

22. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Comparison of single-mode and multimode optical fibers Figure 3.21

23. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Example of communication devices sharing a wireless LAN Figure 3.22

24. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The fundamental concept of multiplexing Figure 3.23

25. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. In the FDM process guard bands separate adjacent channels Figure 3.24

26. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Synchronous time division multiplexing (TDM) Figure 3.25

27. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The concept of statistical TDM Figure 3.26

28. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Example of statistical TDM Figure 3.27

29. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The concept of WDM based on the ITU-T G.692 grid Figure 3.28