blake_ch21.pdf

8/17/2019 blake_ch21.pdf

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9. SCM stands for:a. Service Class Mark c. Signal Class Mark

b. Station Class Mark d. Serial-Code Mode

ANS: B

10. SCM identifies the:a. code number of a cell phone c. signal classification (analog or digital)

b. base-station class d. maximum power level of a cell phone

ANS: D

11. SID stands for:

a. Sequential Interrupt Demand c. System Identification Number

b. Standard Identification Number d. Signal Intensity Descriptor

ANS: C

12. The SID is used by a cell phone to:

a. identify the type of system (analog or digital)b. recognize an AMPS systemc. set its transmitted power level

d. recognize that it is "roaming"

ANS: D

13. DCC stands for:

a. Digital Color Code c. Digital Communications Carrierb. Digital Communications Code d. Direct Channel Code

ANS: A

14. SAT stands for:a. Station Antenna Tower c. Supervisory Access Tone

b. Supervisory Audio Tone d. none of the above

ANS: B

15. CMAC stands for:

a. Control Mobile Attenuation Code c. Central Mobile Access Control

b. Control Mobile Access Code d. Carrier Mode Attenuation Control

ANS: A

16. The CMAC is used to:

a. control access to the cell site

b. set the access code of the cell phone

c. set the transmit power of the cell phone

d. select the transmit channel for the cell phone

ANS: C

17. In an AMPS system, voice is sent using:

a. AM c. FSK


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b. FM d. CDMA

ANS: B

18. In an AMPS system, control-channel signals are sent using:

a. AM c. FSK

b. FM d. CDMA

ANS: C

19. The ERP of a typical handheld AMPS cell phone is:

a. less than 600 µW. c. between 1 and 2 watts

b. less than 600 mW. d. 4 watts

ANS: B

20. BSC stands for:a. Base Station Controller c. Basic Service Contract

b. Base Signal Controller d. Basic Service Code

ANS: A

21. The combination of the mobile cell phone and the cell site radio equipment is called the:

a. BSC c. RF interface

b. MTSO d. air interface

ANS: D

22. The optimum cell-site radius is:

a. 2 km c. as small as possible

b. 0.5 km d. none of the above

ANS: D

23. Phone traffic is measured in:

a. calls c. number of users

b. erlangs d. number of blocked calls

ANS: B

24. One way to increase the capacity of a cell phone system is:

a. increase the number of cells c. increase the ERP

b. decrease the number of cells d. decrease the ERP

ANS: A

25. CDPD stands for:

a. Code-Division Packet Data c. Coded Digital Packet Data

b. Cellular Digital Packet Data d. Cellular Digital Pulse Data

ANS: B

COMPLETION


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1. AMPS uses the ____________________-MHz band.

ANS: 800

2. ____________________ is still the most common cellular phone system in North America.

ANS: AMPS

3. Frequency ____________________ is what makes cellular phone systems complex.

ANS: reuse

4. A ____________________ occurs when an in-use cell-phone moves from one cell site to another.

ANS: handoff

5. If a cell-site radius drops below ____________________ km, handoffs will occur too frequently.

ANS: 0.5

6. The number of ERP classes in AMPS is ____________________.

ANS: three

7. A cell phone permanently installed in a car would be ERP class ____________________.

ANS:I

one

8. The maximum ERP of class III cell phones is ____________________.

ANS: 600 mW

9. A portable, handheld cell phone would be ERP class ____________________.

ANS:

III

three

10. Mobile transmitter power is controlled by the ____________________.

ANS: land station

11. A MAC is a mobile ____________________ code.

ANS: attenuation

12. For security, you should always assume that AMPS transmissions are ____________________.


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ANS: public

13. A mobile switching center is also called an ____________________.

ANS: MTSO

14. The optimum size of a cell site depends on the amount of ____________________.

ANS: traffic

15. Telephone call traffic is measured in ____________________.

ANS: erlangs

16. A cell phone moving into a site with no available frequencies will have a ____________________ call.

ANS: dropped

17. The reduction in cell size to increase traffic is called cell ____________________.

ANS: splitting

18. A ____________________ site is a very small unit that can mount on a streetlight pole.

ANS: microcell

19. Very small cells called ____________________ are used for reliable indoor reception.

ANS: picocells

20. Compared with AMPS, digital cellular phones require ____________________ bandwidth.

ANS: less

SHORT ANSWER

1. Give two reasons why digital cell phone systems are more secure than analog cell phone systems.

ANS:

1. Digital is inherently more secure because of its format.

2. Digitized voice signals are easily encrypted.

2. If a 28.8-kbps modem is being used over a cell phone, how many words of text would be lost during a100-msec handoff interruption assuming 10 bits per letter and 5 letters per word?

ANS:

57.6

3. A certain cell site contains 200 cell phones. The probability that a given cell phone is being used is 15%.

What is the traffic in erlangs?


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ANS:

30

4. What is "trunking gain"?

ANS:For a given probability of being blocked, the maximum allowable traffic per channel increases as the

number of channels increases.

blake_ch21.pdf

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