ISTM 6203-OL
Review 3

1. The device on a digital telephone that converts analog voice signals to digital signals is called _____.
a. analog decoder
b. modem
c. band pass filter
d. multiplexer
e. None of the above.

2. An alternative to PCM for codecs uses the same 8,000 samples per second but requires only 16 possible voice levels. It will generate a data stream of _____.
a. 8 kbps
b. 16 kbps
c. 32 kbps
d. 64 kbps
e. None of the above.

3. In 4-pair UTP, what is twisted?
a. All of the wires are twisted around one another.
b. The wires in each pair are twisted around each other.
c. The wires and the shield
d. Only the shield
d. None of the above.

4. When a signal grows weaker as it travels, it is called _____.
a. transmission
b. noise
c. interference
d. attenuation
e. error

5. The main benefit of parallel transmission over serial transmission is:
a. reliability
b. speed - faster transmission
c. less noise
d. modulation is not required
e. no loss

6. What is the ability to transmit in both directions simultaneously called?
a. parallel transmission
b. full-duplex transmission
c. multiplexed transmission
d. coded transmission
e. bipolar transmission

7. For full-duplex transmission, optical fiber requires _____.
a. one strand
b. two strands
c. four strands
d. eight strands
e. variable, depends on technology

8. Which of the following is a typical wavelength for optical fiber transmission?
a. 850 mm.
b. 850 cm.
c. 850 m.
d. 850 nm.
e. 850 microns.

9. Which can span longer distances?
a. Fiber systems with longer wavelengths.
b. Fiber systems with shorter wavelengths.
c. Both are same
d. Distance depends on the environment
e. None of the above

10. If you have fiber quality of 200 MHz-km, how much bandwidth would you have if you transmit a signal 200 meters?
a. 100 MHz.
b. 200 MHz.
c. 400 MHz.
d. 1 GHz.
e. None of the above.

11. For vertical wiring runs in a building, for telephony firms normally use _____, whereas for data they normally use ________.
a. 4-pair UTP cords, 4 pair UTP cords
b. 25-pair or more copper cable, Fiber
c. 4 pair UTP cords, Fiber
d. Single mode Fiber, Multi-mode fiber
e. 4 pair UTP cords, 25-pair or more copper cable

12. For horizontal wiring in buildings, for telephony firms normally use _____ whereas for data they normally use ________.
a. 1-pair copper wire, 4 pair UTP cords
b. 4 pair UTP cords, 4 pair UTP cords
c. 4 pair UTP cords, Fiber
d. Single mode Fiber, Multi-mode fiber
e. copper cable, fiber cable