Mobile communication Questions and Answers for exam preparation

 

1. What is mobile communication?
   Answer: Wireless communication technology that allows voice, data, and video transmission while users are mobile.

2. What is a cellular network?
   Answer: A type of mobile network divided into cells, each served by a base station for communication.

3. What are the generations of mobile communication?
   Answer: 1G (analog voice), 2G (digital voice), 3G (mobile data), 4G (high-speed internet), 5G (ultra-high speed, IoT).

4. What is a mobile station (MS)?
   Answer: A device (like a smartphone) used by the subscriber to access mobile communication services.

5. Define base transceiver station (BTS).
   Answer: A radio transmitter and receiver providing communication between mobile devices and the network.

6. What is a base station controller (BSC)?
   Answer: Manages multiple BTS and handles resource allocation, handoffs, and call setup.

7. What is handover in mobile networks?
   Answer: The process of transferring a call or data session from one cell to another as the user moves.

8. What is roaming in mobile communication?
   Answer: The ability to access mobile network services outside the subscriber’s home network.

9. What is a subscriber identity module (SIM)?
   Answer: A smart card that stores subscriber information for authentication and network access.

10. What is frequency reuse?
    Answer: Reusing the same frequencies in different cells separated by sufficient distance to avoid interference.

11. What is a control channel?
    Answer: A dedicated channel for transmitting network management and control signals.

12. What is the role of the mobile switching center (MSC)?
    Answer: Manages call routing, connection, and mobility within the mobile network.

13. What is the function of the HLR (Home Location Register)?
    Answer: A database storing subscriber information like authentication, billing, and location.

14. What is the role of the VLR (Visitor Location Register)?
    Answer: Temporarily stores subscriber data for users visiting a different network area.

15. What is a cell in mobile communication?
    Answer: A geographical area served by a BTS in a cellular network.

16. What is cell splitting?
    Answer: Dividing a cell into smaller cells to increase network capacity and coverage.

17. What is GSM?
    Answer: Global System for Mobile Communications, a 2G digital standard for mobile networks.

18. What is CDMA?
    Answer: Code Division Multiple Access, a technology allowing multiple users to share the same frequency band.

19. What is the role of an antenna in mobile communication?
    Answer: Transmits and receives electromagnetic signals for communication.

20. What is modulation?
    Answer: A process of modifying a carrier signal to encode information.

22. What is LTE?
    Answer: Long Term Evolution, a 4G technology offering high-speed wireless communication.

23. What is VoLTE?
    Answer: Voice over LTE, enabling voice calls over 4G networks.

24. What is 5G?
    Answer: The fifth generation of mobile communication providing ultra-fast speeds, low latency, and massive IoT support.

25. What is MIMO?
    Answer: Multiple Input Multiple Output, using multiple antennas for enhanced capacity and performance.

26. What is GPRS?
    Answer: General Packet Radio Service, a 2.5G technology for mobile internet access.

27. What is EDGE?
    Answer: Enhanced Data rates for GSM Evolution, an upgraded 2G technology for faster data speeds.

28. What is the bandwidth of 5G?
    Answer: Operates in sub-6 GHz and mmWave frequencies (24–100 GHz).

29. What is OFDM?
    Answer: Orthogonal Frequency Division Multiplexing, a digital transmission technique used in LTE and 5G.

30. What is a pico cell?
    Answer: A small cellular network covering a small area like an office or a mall.

31. What is a femtocell?
    Answer: A very small base station used to improve indoor coverage.

32. What is call setup time?
    Answer: The time taken to establish a call connection.

33. What is the function of the GMSC (Gateway Mobile Switching Center)?
    Answer: Routes calls from the mobile network to external networks.

34. What is a paging message in mobile networks?
    Answer: A signal sent to locate a mobile device for incoming communication.

35. What is cell breathing?
    Answer: Dynamic adjustment of a cell’s coverage area based on network load in CDMA systems.

36. What is TDM?
    Answer: Time Division Multiplexing, a method of transmitting multiple signals over a single channel.

37. What is FDMA?
    Answer: Frequency Division Multiple Access, a technology allocating separate frequency bands to each user.

38. What is SDMA?
    Answer: Space Division Multiple Access, separating signals by geographic location.

39. What is the difference between uplink and downlink?
    Answer: Uplink is from the device to the base station, and downlink is from the base station to the device.

40. What is WiMAX?
    Answer: A wireless communication standard for long-range internet access.

41. What is beamforming in 5G?
    Answer: Directing signals toward specific users for improved performance.

43. What is the architecture of GSM?
    Answer: Includes MS, BTS, BSC, MSC, HLR, VLR, and other subsystems.

44. What is an IMSI?
    Answer: International Mobile Subscriber Identity, a unique number assigned to each subscriber.

45. What is a TMSI?
    Answer: Temporary Mobile Subscriber Identity, used to enhance user privacy.

46. What is HSPA?
    Answer: High-Speed Packet Access, a 3G technology for faster data transmission.

47. What is carrier aggregation?
    Answer: Combining multiple frequency bands for higher data rates.

48. What is the core network in mobile communication?
    Answer: The central part of the mobile network responsible for routing and managing communication.

49. What is eNodeB?
    Answer: The base station in LTE networks that connects devices to the network.

50. What is the function of the PGW (Packet Gateway)?
    Answer: Handles data traffic between the mobile network and external packet data networks.

51. What is the EPC (Evolved Packet Core)?
    Answer: The core network architecture for LTE, handling data and signaling traffic.

52. What is the difference between GSM and CDMA?
    Answer: GSM uses time and frequency division for access, while CDMA uses code-based division.

54. What is a relay node?
    Answer: A relay node is an intermediary device in a network that retransmits signals to extend coverage and improve connectivity in areas with weak signals.

55. What is mobile IP?
    Answer: Mobile IP is a protocol that allows mobile devices to maintain their IP address while moving between different networks, enabling seamless connectivity.

56. What is the handoff delay?
    Answer: Handoff delay is the time taken to transfer a mobile connection from one cell or base station to another during movement.

57. What is the role of NAT in mobile networks?
    Answer: Network Address Translation (NAT) conserves IP addresses by mapping private IP addresses to a single public IP address when communicating outside the local network.

58. What is the function of DNS in mobile communication?
    Answer: The Domain Name System (DNS) translates human-readable domain names into IP addresses, allowing mobile devices to access resources on the internet.

59. What is network slicing in 5G?
    Answer: Network slicing is a technology in 5G that divides a physical network into multiple virtual networks, each optimized for specific applications, such as IoT or high-speed data.

60. What is the typical latency in 5G networks?
    Answer: Latency in 5G networks is typically around 1 millisecond, significantly lower than previous generations.

61. What is AMR in mobile communication?
    Answer: Adaptive Multi-Rate (AMR) is a speech codec used in GSM and UMTS networks to adjust audio quality based on network conditions.

62. What is carrier-to-noise ratio (CNR)?
    Answer: CNR is the ratio of the carrier signal strength to the background noise level in a communication channel, indicating the quality of the received signal.

63. What is the difference between IPv4 and IPv6?
    Answer: IPv4 uses 32-bit addresses and supports around 4.3 billion devices, while IPv6 uses 128-bit addresses, enabling a vastly larger number of unique addresses.

64. What is soft handoff?
    Answer: Soft handoff occurs when a mobile device connects to a new cell before disconnecting from the old one, ensuring no call drops.

65. What is hard handoff?
    Answer: Hard handoff involves breaking the connection with the old cell before establishing a new connection, which may cause momentary disruption.

66. What is the role of a SIP in VoIP?
    Answer: The Session Initiation Protocol (SIP) manages the initiation, modification, and termination of voice and video communication sessions over IP networks.

67. What is spectral efficiency?
    Answer: Spectral efficiency measures the amount of data transmitted over a given bandwidth in a communication channel, typically expressed in bits per second per Hz.

68. What is an HLR lookup?
    Answer: An HLR lookup retrieves subscriber information from the Home Location Register for tasks like routing calls or authenticating users.

69. What is dual connectivity in LTE/5G?
    Answer: Dual connectivity allows devices to connect simultaneously to LTE and 5G networks, enhancing throughput and reliability.

70. What is SINR in mobile networks?
    Answer: Signal-to-Interference-plus-Noise Ratio (SINR) measures the quality of a wireless signal by comparing it to interference and noise levels.

71. What is the difference between a macro cell and a micro cell?
    Answer: Macro cells cover large areas and serve many users, while micro cells cover smaller areas with fewer users, often for localized capacity improvement.

72. What is carrier frequency offset (CFO)?
    Answer: CFO refers to a mismatch between the transmitter and receiver frequencies, leading to performance degradation.

73. What is the role of HARQ in LTE?
    Answer: Hybrid Automatic Repeat Request (HARQ) improves data reliability by combining error correction and retransmission mechanisms.

75. What is the impact of IoT on mobile communication?
    Answer: IoT significantly increases the number of connected devices, driving the need for efficient communication protocols and advanced network infrastructure.

76. What is the role of AI in mobile networks?
    Answer: AI optimizes resource allocation, enhances traffic prediction, manages network congestion, and improves quality of service (QoS).

77. What is green mobile communication?
    Answer: Green mobile communication focuses on energy-efficient technologies and practices to reduce the environmental impact of mobile networks.

78. What are the key features of 6G?
    Answer: 6G promises ultra-high data rates (up to 1 Tbps), sub-millisecond latency, AI-driven automation, and enhanced IoT integration.

79. What is NB-IoT?
    Answer: Narrowband IoT (NB-IoT) is a low-power wide-area network technology designed for IoT devices, providing extended coverage and low energy consumption.

80. What is the Internet of Vehicles (IoV)?
    Answer: IoV is a network connecting vehicles, infrastructure, and users for real-time communication, enabling autonomous driving and smart transportation systems.

81. How does mobile edge computing work?
    Answer: Mobile edge computing processes data closer to the end-user at the network edge, reducing latency and improving application performance.

82. What is the role of blockchain in mobile networks?
    Answer: Blockchain ensures secure, decentralized, and transparent transactions in mobile networks, enhancing privacy and security.

83. What is the Doppler effect in mobile systems?
    Answer: The Doppler effect causes frequency shifts in signals due to the relative motion between the transmitter and receiver, affecting communication quality.

84. What is the difference between SIM and eSIM?
    Answer: A SIM is a removable physical card, while an eSIM is an embedded chip in devices, allowing remote provisioning of network profiles.

85. What is device-to-device communication?
    Answer: D2D communication allows devices to communicate directly without going through the network infrastructure, improving latency and efficiency.

86. What is the function of a repeater in mobile communication?
    Answer: A repeater amplifies and retransmits signals to extend coverage and improve signal strength in weak areas.

87. What is small cell technology?
    Answer: Small cells are low-power cellular base stations that provide localized coverage in areas with high user density.

88. What is the Shannon capacity theorem?
    Answer: It defines the maximum achievable data rate in a communication channel for a given bandwidth and noise level.

89. What is the significance of 256-QAM in LTE?
    Answer: 256-QAM increases spectral efficiency by encoding more bits per symbol, enhancing data rates in LTE networks.

90. What is the function of the RNC in UMTS?
    Answer: The Radio Network Controller (RNC) manages radio resources, handovers, and communication between the mobile devices and the core network.

91. What is a HetNet?
    Answer: A Heterogeneous Network (HetNet) combines different types of cells (macro, micro, pico, femto) to enhance coverage and capacity.

92. What is TDD in wireless communication?
    Answer: Time Division Duplex (TDD) allows uplink and downlink transmissions on the same frequency at different times.

93. What is the difference between LTE and LTE-A?
    Answer: LTE-A (LTE-Advanced) is an enhanced version of LTE with higher data rates, carrier aggregation, and improved spectral efficiency.

94. What is cooperative communication?
    Answer: Cooperative communication involves multiple devices working together to share resources and enhance network performance