Digital Communications

Multiple Access Techniques for LAN and Access Algorithms

Question 1
Marks : +2 | -2
Pass Ratio : 100%
In which technique, packet size are constant?
Pure Aloha
Slotted Aloha
Pure & Slotted Aloha
None of the mentioned
Explanation:
The Pure Aloha technique has constant packet lengths.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
The interface between the ring and the stations are passive.
True
False
Explanation:
The interface between the rings and the stations are active rather than passive.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
The maximum packet size of Ethernet is
1426 bytes
1526 bytes
1256 bytes
1626 bytes
Explanation:
The maximum packet size of Ethernet is 1526 bytes where a byte is 8 bits.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
In Aloha technique, the re-transmission takes place immediately.
True
False
Explanation:
In Aloha technique if the negative acknowledgment is received, the re-transmission is done after a random delay so that it doesn’t collide again.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
LAN uses _________ cables.
Low bandwidth
High bandwidth
Low & High bandwidth
None of the mentioned
Explanation:
Local area network uses high bandwidth cables for designing.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
The minimum packet size of Ethernet is
81 bytes
75 bytes
72 bytes
64 bytes
Explanation:
The minimum packet size is 72 bytes, consisting of 8 byte preamble, 14 byte header, 46 byte data, 4 byte parity.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
For a throughput of value less than 0.20, which has less average delay?
S-ALOHA
Pure ALOHA
R-ALOHA
None of the mentioned
Explanation:
For a throughput value of less than 0.20, S-ALOHA has less average delay than R-ALOHA.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
A local area network can be used to interconnect
Computers
Terminals
Printers
All of the mentioned
Explanation:
A local area network can be used to interconnect computers, terminals, printers and so on located within a building or a small set of buildings.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
As channel capacity increases, channel throughput
Increases
Decreases
Remains the same
None of the mentioned
Explanation:
As channel capacity R increases, the channel throughput should also increase.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Bit stuffing is done by inserting _____, after ____ consecutive ones.
Zero, seven
Zero, five
One, seven
One, five
Explanation:
Bit stuffing is done by inserting a zero in the data stream after seven consecutive ones.