Quiznetik

Mobile Communication | Set 1

1. Which model of loss system allows the usage of Poisson distribution model for traffic analysis especially by assuming infinite number of users?

Correct : A. lost calls cleared (lcc)

2. Which type of holding time distribution is assumed for the voice conversation on telephone?

Correct : B. exponential

3. If the queuing systems are connected in tandem configuration, what would be the nature of delay?

Correct : A. commutative

4. In analyzing the traffic performance, how is the number of trunk decided with the provision of the Grade of Service (GoS) especially for larger group?

Correct : B. by overload condition

5. By which name/s is the Grade of Service (GOS) well-known?

Correct : A. call congestion

6. How is the relation between Erlang and CCS specified?

Correct : A. 1 erlang = 36 ccs

7. The ratio of number of successful calls to the number of call attempts is known as ______

Correct : A. call completion rate (ccr)

8. Which assumption prooves call arrivals has Poisson's distribution?

Correct : A. pure chance traffic

9. The process in which control signal shares the same path as voice and data is called as __________

Correct : B. inband signalling

10. Percentage of occupancy can be defined as the percentage of _____ for which the server seems to be busy.

Correct : D. time

11. Erlang -B and Erlang-C formulae became foundational results in _________

Correct : C. both 1 and 2

12. A message of one signal unit length is called as _________

Correct : A. single unit message

13. ________ group of trunk's system is more efficient.

Correct : C. large

14. The system in which call requests are kept waiting due to unavailability of trunks is known as ____________

Correct : B. queueing system

15. If a group of trunk is offered 1200 calls during the busy hour & 20 calls are lost along with the average call duration of about 7 min, then what would be the total duration of congestion period?

Correct : C. 57.6 sec

16. Customer line signalling is used for __________

Correct : D. all of the above

17. CCS signalling network is based on __________

Correct : D. all of the above

18. During Busy hour, 1000 calls were offered to a group of trunks and 5 calls were lost. The average call duration was 2 minutes. Find Grade of Service (B)

Correct : B. 0.005

19. A group of 5 trunks is offering 2 Erlangs of traffic. Find the probability that at least one trunk is free.

Correct : D. 0.963

20. During Busy hour, 1200 calls were offered to a group of trunks and 6 calls were lost. The average call duration was 3 minutes. Find Traffic carried(Ac)

Correct : C. 59.7e

21. A group of 20 servers carry a traffic of 10 Erlangs. If average duration of calls is 3 minutes, calculate the no. of calls put through by a single server and a group as a whole in 1 hour period.

Correct : A. 10 calls by single server and 200 calls by a group

22. Over 20 minutes observation interval, 40 subscribers initiate a call. Total duration of calls is 4800sec. Calculate load offered to network by the subscribers and average subscriber traffic?

Correct : C. 4e and 0.1e respectively

23. Formats of signal units in CCTTT no. 7 signalling system are ________________

Correct : D. all of the above

24. Features of CCITT no. 7 signalling system (SS7) are ________________

Correct : D. all of the above

25. If a telephone exchange serves 1500 users with the average BHCA of about 9000 and CCR is about 50%, what would be the busy hour calling rate?

Correct : B. 3

26. Major classes of signalling are ___________

Correct : D. both 2 and 3

27. On an average, one call arrives every 5 seconds. During a period of 10 seconds, what is the probability that no call arrives?

Correct : B. 0.135

28. Standards of CCITT Signalling system are _____

Correct : D. both 1 and 3

29. Inter register signalling can be done by _________

Correct : D. all of the above

30. In Erlang's analysis of efficient telephone line usage he derived the formulae for two important cases, ________,

Correct : D. both 1 and 2

31. What are the types of inter register signalling?

Correct : C. both 1 and 2

32. Erlang determined GoS of lost call system of finite number of trunks based on assumptions: 1. Pure chance traffic 2. Statistical equilibrium 3. Full availability 4. calls which face congestion and get lost

Correct : D. all of the above

33. Traffic tables show relationships of ____________

Correct : D. all of the above

34. A group of 10 servers carry a traffic of 5E. If the average duration of calls is 1.5 minutes, calculate the number of calls put through by a single server and a group as a whole in 1 hr period.

Correct : A. 20 calls and 200 calls

35. A group of 5 trunks carry a traffic of 2E. Find 1. GoS 2. Probability that only one trunk is busy.

Correct : A. 0.037 and 0.275

36. Over 10 minutes observation interval, 20 subscribers initiate a call. Total duration of calls is 2400sec. Calculate load offered to network by the subscribers and average subscriber traffic?

Correct : A. 4e and 0.1e respectively

37. Which among the following represents the flawless hand-off with no perceivable interruption of service?

Correct : B. Soft hand-off

38. If more number of cells are necessary in the frequency reuse distance, then the segmentation & dualization techniques get ________

Correct : A. United

39. Which method of cellular network assists in minimizing the co-channel interference associated with the angle of degree?

Correct : B. Cell Sectoring

40. Which effect is widespread in adjacent-channel interference especially after the reception of a weak signal by a mobile user from the base-station?

Correct : A. Near-far effect

41. Which antennas are used at the center of the cells for the system with hexagonal-shaped cells?

Correct : A. Omni-directional antennas

42. The most comman dial up service used by a person making home telephone call is_____________

Correct : A. Analog Switched Service

43. For Telephone voice Transmission to use a T line, the signal must be __________________ before the multiplexed.

Correct : C. Sampled

44. The propagation model that estimates radio coverage of a transmitter is called ___________

Correct : A. Large scale propagation model

45. The mechanism behind electromagnetic wave propagation cannot be attributed to _____

Correct : D. Sectoring

46. Small scale propagation model is also known as _______

Correct : A. Fading model

47. Which of the following techniques do not help in expanding the capacity of cellular system?

Correct : B. Scattering

48. Which of the following technology distributes the coverage of the cell and extends the cell boundary to hard-to-reach places?

Correct : D. Micro cell zone concept

49. Cell splitting increases the capacity of a cellular system since it increases the number of times ________ are reused.

Correct : B. Channels

50. Small scale variations of a mobile radio signal are directly related to _______

Correct : A. Impulse response of mobile radio channel

51. Discretization of multipath delay axis of impulse response into equal time delay segments is called __________

Correct : A. Excess delay bins

52. In cellular telephone network, which component controls the switching between public wireline telephone network and the base station of cells for supporting the different calls between landline to mobile, mobile to landline and mobile to mobile calls?

Correct : A. Electronic Switching Center (ESC)

53. In a cellular telephone system, which type of interference results from imperfect design of filters in receivers by allowing nearby frequencies to enter the receiver?

Correct : B. Adjacent-channel Interference

54. If the system is designed with the usage of hexagonal-shaped cells, how are the base-stations located?

Correct : D. All of the above

55. Station Busy is sometime called

Correct : B. Slow Busy

56. Relation between gain and effective aperture is given by ______

Correct : A. G=(4πAe)/λ2

57. Which of the following is not an advantage of micro cell zone technique?

Correct : D. Increasing number of base stations

58. Which of the following is not a channel parameter?

Correct : A. Bandwidth

59. Flat fading channel is also known as _____

Correct : A. Amplitude varying channel

60. For fast fading channel, the coherence time of the channel is smaller than _______ of transmitted signal.

Correct : C. Symbol period

61. The time dispersive properties of wideband multipath channel are quantified by ______ and _______

Correct : A. Mean excess delay, rms delay spread

62. The received power of a wideband signal fluctuates significantly when a receiver is moved about a local area. State whether True or False.

Correct : B. false

63. Why is the phase of individual multipath components are not received in RF Pulse system?

Correct : D. Due to use of envelope detector

64. Anyone who uses atelephone or data modem on the telephone circuit is a part of globle communication network called as__________________ and the pair of wires connecting a subscriber to the closest telephone office is called as ____________________.

Correct : D. Public Telephone Network, Local Loop

65. Free space propagation model is to predict ______,Which of the following do not undergo free space propagation?

Correct : A. Received signal strength,Wired telephone systems

66. The free space model predicts that received signal decays as a function of _____

Correct : B. T-R separation

67. Which hand-off stage deals with the relinquishment of unnecessary frequency channels by keeping the availability for other mobile users?

Correct : D. Call Completion

68. Free space propagation model is to predict ______ and Propagation model that characterize rapid fluctuation is called ________

Correct : B. Received signal strength, Fading model

69. Differentiate GSM and DECT.

Correct : A. Both B and C

70. ______ leads to time dispersion and frequency selective fading. What is characteristic of flat fading?

Correct : B. Multipath delay spread, Non linear phase response

71. What is the order of typical values of rms delay spread in outdoor mobile radio channels?

Correct : A. Microseconds

72. Power delay profile and magnitude frequency response of a mobile radio channel are related through _______

Correct : B. Fourier Transform

73. _____ and coherence bandwidth are inversely proportional to one another.Coherence bandwidth is a statistical measure of range of frequencies over which channel is considered _______

Correct : A. Rms delay spread, Flat

74. Verify True or False A.Frequency domain channel sounding technique do not require hard wired synchronization between transmitter and receiver. B.There is no relationship between time domain and frequency domain techniques.

Correct : D. Only B true

75. Which of the following is not an advantage of spread spectrum channel sounding system?

Correct : A. Real time

76. Verify True or False A. Impulse response is a narrowband characterization. B.Impulse response does not play any role in characterization of the channel.

Correct : B. Both Statements False

77. Which of the following is the world’s first cellular system to specify digital modulation and network level architecture?

Correct : A. GSM

78. Who set the standards of GSM?

Correct : C. ETSI

79. Which of the following memory device stores information such as subscriber’s identification number in GSM?

Correct : C. SIM

80. Which of the following does not come under subsystem of GSM architecture?

Correct : D. Channel

81. Which of the following subsystem provides radio transmission between mobile station and MSC?

Correct : A. BSS

82. ____ manages the switching function in GSM.

Correct : B. NSS

83. ______ supports the operation and maintenance of GSM.

Correct : C. OSS

84. Which modulation technique is used by GSM?

Correct : A. GMSK

85. Which one is not a TDMA standard of second generation networks?

Correct : C. AMPS

86. Which is one of the disadvantages of 2G standards?

Correct : D. Limited Internet Browsing

87. The 2G GSM technology uses a carrier separation of _______

Correct : B. 200 KHz

88. GSM is an example of

Correct : A. TDMA cellular systems

89. GSM stands for...

Correct : B. Global System for Mobile Communications

90. What is the air interface between the Mobile Station (MS) and Base Transceiver Station (BTS) called?

Correct : A. Um

91. What is the basic service unit of GSM communications?

Correct : B. Cell

92. The first cellular systems were....

Correct : A. Analogue

93. The Base Station Subsystem (BSS) comprises of what?

Correct : B. The Base Transceiver Station and Base Station Controller

94. The Base Station Controller (BSC) communicates with the Base Transceiver Station (BTS) over what interface?

Correct : C. Abis

95. A duplex transmission is realized in 2G GSM with the help of ……..

Correct : A. FDD

96. FDD stands for ……..

Correct : A. Frequency Division Duplex

97. What is the interface between the BSS and MSC?

Correct : C. A

98. SIM stands for....

Correct : C. Subscriber Identity Module

99. 2G standards support

Correct : C. Both a & b

100. GSM system is a …………..system.

Correct : D. a and b