Module 4

Question 1

List three types of guided media.

Answer 1

Coaxial Cable, Fiber Optic, Twisted Pair

Question 2

Q6-4 We need to use synchronous TDM and combine 20 digital sources each of 100Kbps. Each output slot carries 1 bit from each digital source, but one extra bit is added for synchronization. Answer the following questions.

A) What is the size of an output frame in bits.

B) What is the output frame rate?

C) 1/100000 = 0.0 10 us

D) What is the output data rate 

E) What is the efficiency?

Answer 2

A) What is the size of an output frame in bits.

20 x 1 +1 = 21 21 bits

B) What is the output frame rate?

100,000 frames/second

C) 1/100000 = 0.0 10 us

D) What is the output data rate 100,000 x 21 bits per frame 2100,000 = 2.1Mbps 

E) 20:21

Question 3

P6-8 Four channels, two with a bit rate of 200kbps and two with a bitrate of 150kbps, are to be multiplexed using multiple-slot TDM with no synchronization bits. Answer the following questions:

A) What is the size of a frame in bits?

B) What is the frame rate?

C) What is the duration of a frame?

D) What is the data rate?

Answer 3

A) What is the size of a frame in bits?

B) What is the frame rate? 50,000 frames per second

C) What is the duration of a frame? 1/50,000 = 20us

D) What is the data rate? 700kbps

Question 4

P6-1 Assume that a voice channel occupies a bandwidth of 4KHz. We need to multiplex 10 voice channels with guard bands of 500Hz using FDM. Calculate the required bandwidth.

Answer 4

44.5KHz = (4KHz x 10) + (500Hz) x 9

Question 5

Q6-4 Which of the three multiplexing techniques is (are) used to combine analog signals? Which of the three multiplexing techniques is (are) used to combine digital signals?

FDM, WDM, TDM

Answer 5

FDM - Analog
WDM - Analog
TDM - Digital