ESAT Forouzan - Chapter 13: Multiple Access

Question 1

The most primitive random access method is ______________.
a. ALOHA
b. CSMA
c. Channelization
d. Token passing

Answer 1

a. ALOHA

Question 2

In the ___________ random-access method there is no collision.
a. ALOHA
b. CSMA/CD
c. CSMA/CA
d. Token-passing

Answer 2

c. CSMA/CA

Question 3

In the ___________ random-access method, stations do not sense the medium.
a. ALOHA
b. CSMA/CD
c. CSMA/CA
d. Ethernet

Answer 3

a. ALOHA

Question 4

In the 1-persistent approach, when a station finds an idle line, it _______.
a. Waits 0.1 s before sending
b. Waits 1 s before sending
c. Waits a time equal to 1 - p before sending
d. Sends immediately

Answer 4

d. Sends immediately

Question 5

In the p-persistent approach, when a station finds an idle line, it _______.
a. Waits 1 s before sending
b. Sends with probability 1 – p
c. Sends with probability p
d. Sends immediately

Answer 5

c. Sends with probability p

Question 6

A network using the CSMA random-access method with p equal to 0.25 will send _______ percent of the time after accessing an idle line.
a. 25
b. 50
c. 75
d. 100

Answer 6

a. 25

Question 7

The 1-persistent approach can be considered a special case of the p-persistent approach with p equal to _______.
a. 0.1
b. 0.5
c. 1.0
d. 2.0

Answer 7

c. 1.0

Question 8

____________ is a random-access protocol.
a. MA
b. Polling
c. FDMA
d. CDMA

Answer 8

a. MA

Question 9

___________ is a controlled-access protocol.
a. Reservation
b. FDMA
c. TDMA
d. CSMA

Answer 9

a. Reservation

Question 10

_____________ is (are) a channelization protocol.
a. FDMA
b. TDMA
c. CDMA
d. All the above

Answer 10

d. All the above

Question 11

_______ is the access protocol used by traditional Ethernet.
a. CSMA
b. CSMA/CD
c. CSMA/CA
d. Token ring

Answer 11

b. CSMA/CD

Question 12

When a collision is detected in a network using CSMA/CD, _________.
a. The frame is immediately resent
b. A jam signal is sent by the station
c. The backoff value is set to 0
d. The backoff value is decremented by 1

Answer 12

b. A jam signal is sent by the station

Question 13

In the reservation access method, if there are 10 stations on a network, then there are _______ reservation minislots in the reservation frame.
a. 5
b. 9
c. 10
d. 11

Answer 13

c. 10

Question 14

_______ requires one primary station and one or more secondary stations.
a. Reservation
b. Polling
c. Token ring
d. CSMA

Answer 14

b. Polling

Question 15

When a primary device asks a secondary device if it has data to send, this is called _______.
a. Polling
b. Selecting
c. Reserving
d. Backing off

Answer 15

a. Polling

Question 16

If an FDMA network has eight stations, the medium bandwidth has _______ bands
a. 1
b. 2
c. 8
d. 16

Answer 16

c. 8

Question 17

If a TDMA network has eight stations, the medium bandwidth has _______ bands.
a. 1
b. 2
c. 8
d. 16

Answer 17

a. 1

Question 18

If a CDMA network has eight stations, the medium bandwidth has _______ bands.
a. 1
b. 2
c. 8
d. 16

Answer 18

a. 1

Question 19

A Walsh table for 16 stations has a chip sequence of _______ chips.
a. 4
b. 8
c. 16
d. 32

Answer 19

c. 16