1. NET 222: COMMUNICATIONS AND NETWORKS FUNDAMENTALS ( NET 222: COMMUNICATIONS AND NETWORKS FUNDAMENTALS (PRACTICAL PART) Tutorial 4 : Chapter 5 Data & computer communications Networks and Communication Department 1

2. Chapter 5 pages 176-177 (Data & computer communications) Networks and Communication Department 2  Problems:  5.1  5.6  5.7  5.9  5.11

3. Question Networks and Communication Department 3  5.1 Which of the signals of Table 5.2 use differential encoding?

4. Answer Networks and Communication Department 4  NRZI, Differential Manchester.

5. Question Networks and Communication Department 5  5.6 For the bit stream 01001110, sketch the waveforms for each of the codes of Table 5.2. Assume that the signal level for the preceding bit for NRZI was high; the most recent preceding 1 bit (AMI) has a negative voltage;

6. Answer Networks and Communication Department 6

7. Question Networks and Communication Department 7  5.7 The waveform of Figure 5.25 belongs to a Manchester encoded binary data stream. Determine the beginning and end of bit periods (i.e., extract clock information) and give the data sequence.

8. Answer Networks and Communication Department 8

9. Question Networks and Communication Department 9  5.9 The bipolar-AMI waveform representing the binary sequence 0100101011 is transmitted over a noisy channel. The received waveform is shown in Figure 5.26; it contains a single error. Locate the position of this error and explain your answer.

10. Answer Networks and Communication Department 10  The error is at bit position 7, where there is a negative pulse. For AMI, positive and negative pulses are used alternately for binary 1. The pulse in position 1 represents the third binary 1 in the data stream and should have a positive value.

11. Question Networks and Communication Department 11  5.11 Given the bit pattern 01100, encode this data using ASK, BFSK, and BPSK.

12. Answer Networks and Communication Department 12

13. Any Questions ? The End 13 Networks and Communication Department