Quiznetik

Wireless Sensor Networks (WSN) | Set 2

1. Similarities between WSNs and MANETs networks is.

Correct : B. the nodes communicate each other using multi-hop communication

2. In which network access point is not required?

Correct : A. ad hoc network

3. As the number of nodes___________, every node spends almost all of its time forwarding packets of other nodes

Correct : B. increases

4. A central problem for WSN is to dynamically define and form sensor groups based on__________

Correct : C. both a and b

5. In wireless sensor networks, some of the information defining the objective function and constraints is available only at___________

Correct : B. run time

6. To ensure the ___________of the system, the communication and computation should be localized to relevant sensors only

Correct : C. both a and b

7. Networking allows geographical distribution of the sensor nodes and their placement close to signal sources

Correct : B. statement is correct

8. Within the coverage range, communication is done by__________

Correct : B. broadcast

9. ___________sub-layer manages access to the physical network medium, and its fundamental goal is to reduce or avoid packet collisions in the medium

Correct : A. mac

10. Following characteristics of wireless sensor networks point to the need for a specialized MAC protocol

Correct : D. all of above

11. Following MAC protocols have been developed for wireless voice and data communication networks

Correct : D. all of above

12. The main goal of the ___________is to reduce energy waste caused by idle listening, collisions, overhearing and control overhead

Correct : A. s-mac protocol

13. The S-MAC protocol includes following major components

Correct : D. all of above

14. In the S-MAC protocol, ___________is designed to reduce energy consumption during the long idle time when no sensing events happen, by turning off the radio periodically

Correct : B. periodic listen and sleep

15. Examples of data attributes may include

Correct : D. all of above

16. It may be more economical to use a smaller transmission radius for nodes in areas of high node density, w/o sacrificing adequate network connectivity. This is the issue of___________

Correct : A. topology control

17. Which multiple access technique is used by IEEE 802.11 standard for wireless LAN?

Correct : C. cdma/ca

18. What is the size of MAC Address?

Correct : C. 48-bits

19. This is what happens if two devices on the same Ethernet network determine the network is free, but attempt to transmit data at exactly the same time.

Correct : C. collision

20. This describes how the Ethernet protocol regulates communication among connection points.

Correct : A. carrier sense multiple access/collision detect

21. 802.11 wireless networking uses what method as the media access method?

Correct : C. csma/ca

22. ____________ assigns a unique number to each IP network adapter called the MAC address.

Correct : A. media access control

23. In ________ each station sends a frame whenever it has a frame to send.

Correct : A. pure aloha

24. In pure ALOHA, the vulnerable time is ______ the frame transmission time.

Correct : B. two times

25. In __________, each station is forced to send only at the beginning of the time slot.

Correct : B. slotted aloha

26. In ________, a station monitors the medium after it sends a frame to see if the transmission was successful. If so, the station is finished. If, however, there is a collision, the frame is sent again.

Correct : B. csma/cd

27. To avoid collisions on wireless networks, ________was invented.

Correct : A. csma/ca

28. In _______, collisions are avoided through the use of three strategies: the interframe space, the contention window, and acknowledgments.

Correct : A. csma/ca

29. In _______ methods, the stations consult one another to find which station has the right to send.

Correct : B. controlled access

30. In _______ methods, a station cannot send unless it has been authorized by other stations.

Correct : B. controlled access

31. In the ________ method, a station needs to make a reservation before sending data. Time is divided into intervals.

Correct : A. reservation

32. In the ______ method, all data exchanges must be made through the primary device even when the ultimate destination is a secondary device.

Correct : B. polling

33. In the _______ method, the primary device controls the link; the secondary devices follow its instructions.

Correct : B. polling

34. In ______, each station is allocated a band to send its data. In other words, each band is reserved for a specific station, and it belongs to the station all the time.

Correct : A. fdma

35. In _______, the stations share the bandwidth of the channel in time.

Correct : B. tdma

36. In _____, each station is allocated a time slot during which it can send data. Each station transmits its data in its assigned time slot.

Correct : B. tdma

37. In _____, each station transmits its data in its assigned time slot.

Correct : B. tdma

38. W-CDMA is ____.

Correct : A. wireless code division multiple access

39. You have 5 information signals and only one transmitter. What technique will help in transmitting all the 5 signals?

Correct : B. multiplexing

40. RTS/CTS period is called ( )

Correct : A. waiting period

41. Which is not a variant of S-MAC?

Correct : D. data gathering (dmac)

42. Fading of the received radio signals in a mobile communication environment occurs because of .....

Correct : B. multipath propagation

43. In .............. Frequency Spectrum is divided into smaller spectra and is allocated to each user.

Correct : C. fdma

44. In ................ multiple access is achieved by allocating different time slots for the different users.

Correct : A. tdma

45. A antenna which attempts to direct all its energy in a particular direction is called as a .............

Correct : A. directional antenna

46. Which of the FCC's RF bands operates in the frequency range of 2.4 GHz to 2.4835 GHz

Correct : A. ism

47. What is the term used to identify the broadcast or generated electrical signals that can disrupt wireless communications?

Correct : A. rfi

48. Which one of the following devices rebroadcasts the signals it receives after conditioning them for increased strength and clarity?

Correct : B. repeater

49. Wireless networks transmit using RF signals, which require a __________ to receive and transmit signals through the air.

Correct : C. antenna

50. Which one of the following RF band is allocated to the Industrial, Scientific and Medical industry?

Correct : D. 2.4 ghz to 2.4835 ghz

51. Since a wireless ad-hoc network is decentralized and its topology is dynamic, each of the wireless nodes must perform its own message __________.

Correct : A. forwarding

52. What is the networking device used to forward packets on a packet-switching network?

Correct : D. router

53. What signal transmission method intersperses message segments from multiple sessions into a single medium?

Correct : B. multiplexing

54. What is the term used to describe the height of a radio wave?

Correct : B. amplitude

55. Which of the RF multiplexing methods uses times slices to carry multiple data streams on a single carrier?

Correct : C. tdm

56. The general rule of __________ is the inverse-square law, which measures an electromagnetic wave's strength relative to the distance over which it is transmitted.

Correct : D. propagation

57. The __________ is designed to radiate the aura of the electromagnetic field created by the electric current.

Correct : B. antenna

58. __________ communications mode means that it can both transmit and receive, but only one action at a time.

Correct : D. half duplex

59. The radio communication spectrum is divided into bands based on ______.

Correct : A. frequency

60. Which of the following is a type of wireless network interference that can originate from a nearby radio wave transmitter?

Correct : B. rfi

61. What type of interference is emitted by nearby electrical motors, appliances, or faulty connections?

Correct : D. emi

62. What is the receive signal strength indicator used to measure?

Correct : C. the strongest signal on a particular channel at a specific location.

63. What is the measurement used to indicate the amount of interference to a particular location?

Correct : B. snr

64. Which of these is not true for Time-Division Duplex (TDD)?

Correct : C. it increases the battery life of mobile phones

65. Densor sensor field---------- the odds of detecting a signal source within the range

Correct : A. increases

66. As the number of nodes___________, every node spends almost all of its time forwarding packets of other nodes

Correct : B. increases

67. select the incorrect statement

Correct : B. radio communication is the less expensive operation a node performs in terms of energy usage

68. select the incorrect statement

Correct : D. wireless communication between nodes utilizes optical link links

69. select the incorrect statement

Correct : C. sensor networks are typically deployed in structured manner

70. Within the coverage range, nodes communication is by__________

Correct : B. broadcast

71. ___________sub-layer manages access to the physical network medium, and its fundamental goal is to reduce or avoid packet collisions in the medium

Correct : C. mac

72. Following characteristics of wireless sensor networks point to the need for a specialized MAC protocol

Correct : D. all of above

73. The main goal of the ___________is to reduce energy waste caused by idle listening, collisions, overhearing and control overhead

Correct : A. s-mac protocol

74. The S-MAC protocol includes following major component

Correct : D. all of above

75. The S-MAC protocol includes following major component

Correct : C. a and b both

76. In the S-MAC protocol, ___________is designed to reduce energy consumption during the long idle time when no sensing events happen, by turning off the radio periodically

Correct : B. periodic listen and sleep

77. __________in S-MAC is similar to the using an RTS/CTS exchange

Correct : A. collision avoidance

78. Following aspects of the energy cost in a sensor network make it challenging to reason about optimizing energy

Correct : D. a and b both

79. select the correct statement

Correct : A. since the nodes operate independently, their clocks may not be synchronized with one another

80. select the correct statement

Correct : C. a and b both

81. The latency in channel can be decomposed into following components

Correct : D. alln of above

82. The latency in channel can be decomposed into following components

Correct : C. a and b both

83. The Send time is

Correct : A. this is the time taken by the sender to construct the message

84. The Access time is

Correct : B. this is the delay incurred while waiting for access to the transmission channel due to contention, collisions etc

85. The Propagation time is

Correct : C. this is the time for message to travel across the channel to the destination node

86. The Receive time is

Correct : D. this is the time for the network interface on the receiver side to get the message and notify the host of its arrival

87. Receiving power additionally influenced by

Correct : D. all of above

88. Incorrect statement about Time and frequency multiplexing in combination is

Correct : D. no precise coordination required

89. in case of hidden terminal problem

Correct : B. two senders are not in the communication range of each other

90. in case of exposed terminal problem

Correct : A. two senders are in the communication range of each other

91. Throughput is defined as the number of bits or bytes successfully

Correct : C. transmitted per time unit t

92. Design Criteria for Medium Access Protocols

Correct : A. maximize the throughput by minimizing the delay and energy spent.

93. Design Criteria for Medium Access Protocols

Correct : B. to minimize the time in listening mode as much as possible.

94. Microcontroller has current drawn typically of 1.8 mA and 5.1 µA respectively in

Correct : A. active mode and sleep mode

95. RF Transceiver draws more current in

Correct : C. transmit mode

96. In centralized TDMA,

Correct : B. the schedule is calculated offline and provided to the sensor nodes at startup.

97. When a node has a packet to send, it listens for traffic on the channel.

Correct : C. if the channel is free, it initially sends message, rts.

98. If the channel is busy, continues sensing the channel until it becomes idle again.

Correct : A. 1-persistent csma

99. If the channel is busy, it back-offs for a random amount of time and then retries.

Correct : B. non-persistent csma

100. This version is time scheduled. A central controller in the network assigns a fixed transmission order

Correct : D. o-persistent csma