Read Chapter 6. Also read Lesson 6 on this web site.  Then, complete this homework. Work to understand all problems even though all problems may not be assigned.

1. Define the following terms using your own words and complete sentences.  Don't just write the acronym.

a) start bit
b) odd parity
c) even parity
d) idle bits
e) stop bit
f) framing error
g) flag bits
h) half duplex
i) FDD
j) DCE

2. What is the difference between full and half duplex transmission?

3. Add even parity bits to the following:

a) 0110100
b) 0000110
c) 1110101

4. What would the 7-bit ASCII sequence be for:

a) upper case B
b) comma
c) backspace
d) space

5. Beginning with one start bit followed by 21 data bits, 2 parity bits and 1 stop bit:

a) What are the total number of bits in the frame?

b) What would the overhead and throughput be (answer in percent)?

c) How many ASCII characters could be carried in this frame?

d) What data rate would you need in order to deliver 9,600 ASCII characters per second to the destination?

6. A transmitter sends 100 bits per second but the receiver's clock runs too slowly causing it to measure once every 0.0107 seconds.  How many bits are measured in a row before the receiver misses a bit?

[Hint: After measuring the first bit, measurements get later and later with each incoming bit.  Eventually, the measurement drifts more than half a bit time and lands in the following bit.  Assume the first bit is measured exactly in the center of the bit time.]

7. How slowly could the receiver in question 6 measure the incoming bits and still measure 12 bits in a row correctly?

[Hint:  Think about how much the measurement can drift per bit so that the total drift over 12 bits is not more than half a bit time.]

Used with permission of the Author; Copyright (C) Kevin A. Shaffer 1998 - 2018, all rights reserved.