1. (8pts) What is the difference between half-duplex and full-duplex transmission modes in term of capacity utilization and flow of data?

2. (12pts) What is a protocol? What are the key elements of a protocol? Give an example of a networking protocol?

3. (14pts) What is a standard? What are the two categories of standards? Name three organizations that are establishing, reviewing and publishing standards?

4. (8pts) For each of the following four networks, discuss the consequences if a connection fails.
   1. Five devices arranged in a mesh topology
   2. Five devices arranged in a star topology (not counting the hub)
   3. Five devices arranged in a bus topology
   4. Five devices arranged in a ring topology

5. (8pts) Explain two differences between a LAN and a WAN?

6. (8pts) For n devices in a network, what is the number of cable links required for a mesh, ring, bus, and star topology?

7. (8pts) Cite an advantage for each of the four basic network topologies (mesh, ring, bus, and star).

8. (4pts) What are the advantages of a multipoint connection over a point-to-point connection?

9. (6pts) What is the number of bits per baud for the following techniques?
   1. ASK with four different amplitudes
   2. FSK with 8 different frequencies
   3. PSK with four different phases

10. (6pts) Which characteristics of an analog signal are changed to represent the lowpass analog signal in each of the following analog-to-analog conversions?
    1. AM
    2. FM
    3. PM

11. (9pts) Find the bandwidth for the following situations if we need to modulate a 5-KHz voice.
    1. AM
    2. FM (set =5)
    3. PM (set =1)

12. (4pts) Define analog transmission.

13. (4pts) Define digital-to-analog conversion.

14. (4pts) Define analog-to-analog conversion.

15. (4pts) Distinguish between a link and a channel in multiplexing.

16. (15pts) We need to use synchronous TDM and combine 20 digital sources, each of 100 Kbps. Each output slot carries 2 bit from each digital source, but one extra bit is added to each frame for synchronization. Answer the following questions:
    1. What is the size of an output frame in bits?
    2. What is the output frame rate?
    3. What is the duration of an output frame?
    4. What is the output data rate?
    5. What is the efficiency of the system (ratio of useful bits to the total bits).

17. (4pts) Define FHSS and explain how it achieves bandwidth spreading.

18. (4pts) Distinguish between a signal element and a data element.

19. (4pts) Distinguish between data rate and signal rate.

20. (8pts) What is the Nyquist sampling rate for each of the following signals?
    1. A low-pass signal with bandwidth of 200 KHz?
    2. A band-pass signal with bandwidth of 200 KHz if the lowest frequency is 100 KHz?

21. (6pts) What is the maximum data rate of a channel with a bandwidth of 500 KHz if we use eight levels of digital signaling.

22. (6pts) What are the differences between parallel and serial transmission?

23. (12pts) Calculate the value of the signal rate for each of the following cases if the data rate is 24 Mbps and c =1/5
    1. r=1
    2. r=1/2
    3. r=2
    4. r=4/3