ESAT Forouzan - Chapter 15: Wireless Lans

Question 1

A wireless LAN using FHSS hops 10 times per cycle. If the bandwidth of the original signal is 10 MHz, the spread spectrum is _____ MHz.
a. 10
b. 100
c. 1000
d. 10,000

Answer 1

b. 100

Question 2

A wireless LAN using FHSS hops 10 times per cycle. If the bandwidth of the original signal is 10 MHz and 2 GHz is the lowest frequency, the highest frequency of the system is _____ GHz.
a. 1.0
b. 2.0
c. 2.1
d. 3.0

Answer 2

c. 2.1

Question 3

An FHSS wireless LAN has a spread spectrum of 1 GHz. The bandwidth of the original signal is 250 MHz, and there are _____ hops per cycle.
a. 1
b. 2
c. 3
d. 4

Answer 3

d. 4

Question 4

A wireless LAN using DSSS with an 8-bit chip code needs _____ MHz for sending data that originally required a 10-MHz bandwidth.
a. 2
b. 8
c. 20
d. 80

Answer 4

d. 80

Question 5

A wireless LAN using DSSS with _____-bit chip code needs 320 MHz for sending data that originally required a 20-MHz bandwidth.
a. A 2
b. An 8
c. A 16
d. A 32

Answer 5

c. A 16

Question 6

A wireless LAN using DSSS with a 4-bit chip code needs 10-MHz for sending data that originally required a _____-MHz bandwidth.
a. 2.5
b. 20
c. 25
d. 40

Answer 6

a. 2.5

Question 7

In an ESS the _____ station is not mobile.
a. AP
b. Server
c. BSS
d. None of the above

Answer 7

a. AP

Question 8

In an ESS the _____ stations are part of a wired LAN.
a. AP
b. Server
c. BSS
d. All of the above

Answer 8

a. AP

Question 9

A station with _____ mobility can move from one BSS to another.
a. No-transition
b. BSS-transition
c. ESS-transition
d. B and C

Answer 9

b. BSS-transition

Question 10

A station with _____ mobility can move from one ESS to another.
a. No transition
b. BSS-transition
c. ESS-transition
d. B and C

Answer 10

c. ESS-transition

Question 11

A station with _____ mobility is either stationary or moving only inside a BSS.
a. No-transition
b. BSS
c. ESS
d. A and B

Answer 11

a. No-transition

Question 12

A _____ frame usually precedes a CTS frame.
a. DIFS
b. SIFS
c. RTS
d. Any of the above

Answer 12

c. RTS

Question 13

A _____ frame usually precedes an RTS frame.
a. DIFS
b. CIFS
c. CTS
d. None of the above

Answer 13

d. None of the above

Question 14

Stations do not sense the medium during _____ time.
a. RTS
b. CTS
c. SIFS
d. NAV

Answer 14

d. NAV

Question 15

Wireless transmission is _____ prone to error than/as wired transmission.
a. More
b. Less
c. Half as
d. None of the above

Answer 15

a. More

Question 16

Which MAC sublayer does IEEE 802.11 define?
a. LLC
b. PCF
c. DCF
d. B and C

Answer 16

d. B and C

Question 17

What is the basic access method for wireless LANs as defined by IEEE 802.11?
a. LLC
b. DCF
c. PCF
d. BFD

Answer 17

b. DCF

Question 18

The access method for wireless LANs as defined by IEEE 802.11 is based on ______.
a. CSMA
b. CSMA/CD
c. CSMA/CA
d. Token passing

Answer 18

c. CSMA/CA

Question 19

FHSS, DSSS, and OFDM are ______ layer specifications.
a. Physical
b. Data link
c. Network
d. Transport

Answer 19

a. Physical

Question 20

In the ______ method, the sender hops from frequency to frequency in a specific order.
a. FHSS
b. DSSS
c. OFDM
d. HR-DSSS

Answer 20

a. FHSS

Question 21

A wireless LAN uses ______ frames for acknowledgement.
a. Management
b. Control
c. Data
d. None of the above

Answer 21

b. Control

Question 22

A wireless LAN uses ______ frames for the initial communication between stations and the access points.
a. Management
b. Control
c. Data
d. None of the above

Answer 22

a. Management

Question 23

A Bluetooth network can have ______ meter(s).
a. One
b. Two
c. Three
d. Eight

Answer 23

a. One

Question 24

______ combine to form a scatternet.
a. BSSs
b. ESSs
c. APs
d. Piconets

Answer 24

d. Piconets

Question 25

Bluetooth uses _____ in the physical layer.
a. FHSS
b. DSSS
c. DHSS
d. OFDM

Answer 25

a. FHSS

Question 26

A bluetooth frame needs ______ μs for hopping and control mechanisms.
a. 625
b. 259
c. 3
d. a multiple of 259

Answer 26

b. 259