Read Chapter 8 in your text and lesson 8 on this web site. Then complete this hw8. Work to understand all problems even though all problems may not be assigned

1. Compare and contrast FDM with TDM.

2. Human voice:

a. What is the strongest frequency in the typical human voice?

b. What is the typical range of frequencies in human voice?

c. When digitizing an analog voice signal, how many times per second should it be sampled?

3. Draw a DS0 frame and label the least significant bit, the most significant bit and the first bit to be sent.

4. Draw a DS1 frame and label it in detail.

5. ISDN

 a. What is the data rate for a single BRI channel (which does not use bit robbing)?

b. Some home ISDN "modems" will combine two BRI channels together.  What would the data rate be if you could use both channels simultaneously for data transmission?

c. What is the data rate of a single channel on a T1 connection that does not use bit robbing?

d.  What is the overhead of a DS1 frame that uses bit robbing?

6. What are the advantages of using extended super frame rather than superframe or standard DS1 framing?

7. An E1 is the European version of our T1.  An E1 frame has 32 channels.  The first channel is channel 0.  All 8 bits of channel 0 are used for framing.  Channels 1 to 15 are used for data or voice and no bit robbing is used or needed.  Channel 16 is used for control information on all the voice and data channels.  Channels 17 to 31 are also for voice or data.

a. How many channels are overhead?

b. How many channels can be used to send data?

c. What is the overhead and the through put for an E1 frame?

d. Using the magic number, what is the total data rate used to send E1 frames?

e. What is the data rate for the users information?

f. How many framing bits are sent in one second?

8. Define upstream and downstream with respect to xDSL services.

9. Echo cancelation increases the cost of subscriber equipment but what is the main advantage of using it?

10. What is a headend ?

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