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DCO MCQ, UNIT III, 1. The sharing of a medium and its link by two or more devices is called _________, a) Fully duplexing, b) Multiplexing, c) Micropleixng, d) Duplexing, Answer: b, 2. Multiplexing is used in _______, a) Packet switching, b) Circuit switching, c) Data switching, d) Packet & Circuit switching, Answer: b, 3. Which multiplexing technique used to transmit digital signals?, a) FDM, b) TDM, c) WDM, d) FDM & WDM, Answer: b, 4. If there are n signal sources of same data rate, then the TDM link has _______ slots., a) n, b) n/2, c) n*2, n, d) 2, Answer: a, 5. If link transmits 4000 frames per second, and each slot has 8 bits, the transmission rate of circuit this TDM is, _________, a) 32kbps, b) 500bps, c) 500kbps, d) 32bps, Answer: a, Transmission rate= frame rate * number of bits in a slot., Given: Frame rate = 4000/sec and number of bits in slot = 8, Thus, Transmission rate = (4000 * 8) bps, = 32000bps, = 32kbps, 6. The state when dedicated signals are idle are called __________, a) Death period, b) Poison period, c) Silent period, d) Stop period, Answer: c, 7. Multiplexing provides _________, a) Efficiency, b) Privacy

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c) Anti jamming, d) Both Efficiency & Privacy, Answer: d, 8. In TDM, the transmission rate of a multiplexed path is always _______ the sum of the transmission rates of, the signal sources., a) Greater than, b) Lesser than, c) Equal to, d) Equal to or greater than, Answer: a, 9. In TDM, slots are further divided into _________, a) Seconds, b) Frames, c) Packets, d) Bits, Answer: b, 10. The sharing of a medium and its link by two or more devices is called?, a) Fully duplexing, b) Multiplexing, c) Micropleixng, d) Duplexing, Answer: Option b, 11. Multiplexing is used in?, a) Packet switching, b) Circuit switching, c) Data switching, d) Packet & Circuit switching, Answer: Option B, 12. Which multiplexing technique used to transmit digital signals?, a) FDM, b) TDM, c) WDM, d) FDM & WDM, Answer: Option B, 13. The transmission bandwidth of spread spectrum techniques is equal to the minimum required signal, bandwidth., a) True, b) False, Answer: b, 14. Why spread spectrum technique is inefficient for a single user?, a) Large transmission bandwidth, b) Small transmission bandwidth, c) Fixed transmission bandwidth, d) Fixed null bandwidth, Answer: a, 15. Which of the following is not a property of spread spectrum techniques?, a) Interference rejection capability, b) Multipath fading, c) Frequency planning elimination

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d) Multiple user, multiple access interface, Answer: b, 16. DSSS system spreads the baseband signal by ________ the baseband pulses with a pseudo noise sequence., a) Adding, b) Subtracting, c) Multiplying, d) Dividing, Answer: c, 17. Frequency hopping involves a periodic change of transmission _______, a) Signal, b) Frequency, c) Phase, d) Amplitude, Answer: b, 18. What is the set of possible carrier frequencies in FH-SS?, a) Hopset, b) Hop, c) Chips, d) Symbols, Answer: a, 19. The bandwidth of the channel used in the hopset is called _________, a) Hopping bandwidth, b) Total hopping bandwidth, c) Instantaneous bandwidth, d) 3 dB bandwidth, Answer: c, 20. The processing gain of FH systems is given by ratio of _______, a) Hopping bandwidth and hopping period, b) Instantaneous bandwidth and hopping duration, c) 3 dB bandwidth and bit rate, d) Total hopping bandwidth and instantaneous bandwidth, Answer: d, 21. FH systems do not have collisions., a) True, b) False, Answer: b, 22. In fast frequency hopping, hopping rate is less than the information symbol rate., a) True, b) False, Answer: b, 23. Virtual-Circuit Networks and datagram networks are sub categories of, a) Message-switched networks., b) Packet-switched networks., c) Circuit-switched networks., d) None of them., Answer» B. packet-switched networks.

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24. Which of the following is not a characteristic of Virtual Circuit Network?, a) There are setup and teardown phases in addition to the data transfer phase, b) Resources can be allocated during setup phase or on demand, c) All packets follow the same path established during the connection, d) Virtual circuit network is implemented in application layer, Answer: d, 25. The address that is unique in the scope of the network or internationally if the network is part of an, international network is called as ______, a) Global address, b) Network address, c) Physical address, d) IP address, Answer: a, 26. The Identifier that is used for data transfer in virtual circuit network is called _______, a) Global address, b) Virtual circuit identifier, c) Network identifier, d) IP identifier, Answer: b, 27. Which of the following is not a phase of virtual circuit network?, a) Setup phase, b) Data transfer phase, c) Termination phase, d) Teardown phase, Answer: c, 28. During teardown phase, the source, after sending all the frames to destination, sends a _____ to notify, termination., a) teardown response, b) teardown request, c) termination request, d) termination response, Answer: b, 29. Delay of the resource allocated during setup phase during data transfer is ________, a) constant, b) increases for each packet, c) same for each packet, d) different for each packet, Answer: c, 30. Delay of the resource allocated on demand during data transfer is ________, a) constant, b) increases for each packet, c) same for each packet, d) different for each packet, Answer: d, 31. In virtual circuit network, the number of delay times for setup and teardown respectively are _______, a) 1 and 1, b) 1 and 2, c) 2 and 1, d) 2 and 2

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Answer: a, 32. In data transfer phase, how many columns does the table contain?, a) 1, b) 2, c) 3, d) 4, Answer: d, 33. Packet-switched networks can also be divided into _________ subcategories: virtual-circuit networks and, datagram networks., A) five, B) three, C) two, D) four, Answer: Option C, , 34. In __________, each packet is treated independently of all others., A) circuit switching, B) datagram switching, C) frame switching, D) none of the above, Answer: Option B, 35. Based on the Clos criteria, if N = 200, then k must be equal to or greater than _________., A) 19, B) 21, C) 31, D) 41, Answer: Option A, 36. In _________, resources are allocated on demand., A) circuit switching, B) datagram switching, C) frame switching, D) none of the above, Answer: Option B, 37. In _______ switching, the paths in the circuit are separated from one another spatially., A) time-division, B) two-dimensional, C) space-division, D) three-dimensional, Answer: Option C, 38. In a ________ network, two types of addressing are involved: global and local., A) datagram, B) virtual-circuit, C) circuit-switched, D) none of the above, Answer: Option B, , 39. A ________ network is made of a set of switches connected by physical links, in which each link is divided, into n channels., A) circuit-switched

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B) line-switched, C) frame-switched, D) none of the above, Answer: Option A, 40. In _________, there is no resource allocation for a packet., A) circuit switching, B) datagram switching, C) frame switching, D) none of the above, Answer: Option B, 41. A _________ network is a cross between a circuit-switched network and a datagram network. It has some, characteristics of both., A) packet-switched, B) frame-switched, C) virtual-circuit, D) none of the above, Answer: Option C, 42. The most popular technology in time-division switching is called the _________., A) TSI, B) STI, C) ITS, D) none of the above, Answer: Option A, 43. A switched WAN is normally implemented as a _______ network., A) virtual-circuit, B) datagram, C) circuit-switched, D) none of the above, Answer: Option A, 44. A switch in a datagram network uses a routing table that is based on the ______ address., A) destination, B) source, C) local, D) none of the above, Answer: Option A, 45. Traditionally, _____ methods of switching have been important., A) six, B) five, C) four, D) three, Answer: Option D, 46. Circuit switching takes place at the ________ layer., A) physical, B) data line, C) network, D) transport, Answer: Option A