EC-803-A Wireless Networks - May 2024 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aDescribe the evolution of mobile telecommunication systems from GSM to UMTS (Universal Mobile Telecommunication System) in terms of the advancements in data transmission rates, coverage, and service offered.
   How to answer

   • Definition of GSM (2G) and UMTS (3G) with core network difference
   • Data rates: GSM 9.6 kbps / GPRS / EDGE vs UMTS up to 2 Mbps
   • Coverage, capacity and switching: circuit vs packet
   • Services: voice/SMS vs multimedia, internet, video
2. Marks
   bExplain the key features and advantages of HIPERLAN (High-Performance Radio Local Area Network) compared to IEEE 802.11 standards.
   How to answer

   • HIPERLAN definition and types / standards
   • Key features: high data rate, QoS, security, frequency band
   • Advantages over IEEE 802.11
   • Comparison table
3. 7 Marks
   aWhat is Wireless ATM (Asynchronous Transfer Mode)? How does it enable high-speed data transmission in wireless networks? Explain.
   How to answer

   • Definition of Wireless ATM and 53-byte cell concept
   • Adaptation to wireless: mobility, error control, handoff
   • How it enables high-speed transmission: fixed cells, QoS, multiplexing
   • Limitations / relevance
4. 7 Marks
   bWhat is the role of 3GPP in setting standards for mobile communication technologies, specifically LTE and LTE-A? Discuss the key objectives and principles underlying the LTE and LTE-A.
   How to answer

   • Role of 3GPP as standards body
   • LTE objectives: high data rate, low latency, all-IP
   • LTE-A objectives: carrier aggregation, higher MIMO, relay
   • Underlying principles: OFDMA, SC-FDMA, flat architecture
5. 7 Marks
   aDescribe the E-UTRAN (Evolved Universal Terrestrial Radio Access Network) architecture and its components for mobility management and resource allocation in LTE networks.
   How to answer

   • E-UTRAN definition and flat architecture concept
   • Components: eNodeB, UE, MME, S-GW, X2/S1 interfaces
   • Mobility management: handover, cell selection
   • Resource allocation: scheduling, bearer management
6. 7 Marks
   bDifferentiate between SISO and MIMO systems in wireless communication. How does MIMO technology improve signal reliability, coverage, and data rates in LTE networks compared to traditional SISO systems?
   How to answer

   • Definitions of SISO and MIMO
   • Difference table: antennas, capacity, diversity
   • MIMO gains: spatial multiplexing, diversity, beamforming
   • Impact on reliability, coverage and data rate in LTE
7. 7 Marks
   aWhat is a Wireless Sensor Network (WSN) and how does it differ from traditional wired networks? Explain the architecture of a WSN.
   How to answer

   • Definition of WSN and sensor node components
   • Differences from wired: energy, topology, reliability, mobility
   • WSN architecture: layered / clustered, sink, gateway
   • Diagram of WSN architecture
8. 7 Marks
   bDiscuss the challenges for Underwater Wireless Sensor Networks (UWSNs).
   How to answer

   • Definition of UWSN and underwater environment
   • Challenges: propagation delay, limited bandwidth, energy
   • Localization, deployment and communication issues
   • Effect on protocol design
9. 7 Marks
   aDiscuss the security challenges in Wireless Sensor Networks (WSN) and the techniques used to ensure data confidentiality, integrity, and authenticity.
   How to answer

   • Security threats in WSN: eavesdropping, spoofing, DoS
   • Requirements: confidentiality, integrity, authenticity
   • Techniques: encryption, key management, authentication
   • Lightweight protocols due to resource constraints
10. 7 Marks
    bIn wireless environments, how do routing algorithms ascertain the most efficient path for transmitting data? Also explain how they mitigate network congestion and guarantee the timely delivery of packets?
    How to answer

    • Role of routing in efficient path selection: metrics
    • Examples of wireless routing algorithms
    • Congestion mitigation: load balancing, multipath
    • Timely delivery: QoS, prioritization, reliability
11. 7 Marks
    aCompare the following:

    1. i)IPv4 and IPv6 addressing
    2. ii)TCP and UDP
    How to answer

    • IPv4 vs IPv6: address size, header, security, auto-configuration
    • TCP vs UDP: connection, reliability, overhead, use cases
    • Tabular comparison for both pairs
    • Suitability for wireless networks
12. 7 Marks
    bBriefly explain the enhancements and modifications made in indirect TCP, Reno, New-Reno, Tahoe, and Vegas TCP variants to improve performance in mobile and wireless networks.
    How to answer

    • Need for Indirect TCP in wireless with mobility
    • Reno: fast retransmit / fast recovery
    • New-Reno, Tahoe differences in congestion control
    • Vegas: delay-based improvement and performance in wireless
13. 7 Marks
    aDescribe the architecture of the Internet of Things (IoT) and its key components.
    How to answer

    • IoT definition and layered architecture
    • Key components: sensors, connectivity, cloud, analytics
    • Protocols and devices role
    • Diagram of IoT architecture
14. 7 Marks
    bWrite a case study on the implementation of a Sensor Body Area Network (BAN).
    How to answer

    • BAN concept and medical need
    • Implementation steps: sensors, coordinator, communication
    • Case study example: patient monitoring
    • Results, challenges and benefits
15. 14 Marks
    Write short notes on (any two)

    1. a)WiMAX
    2. b)Zigbee
    3. c)IEEE 802.15 WPAN
    4. d)GAGAN
    How to answer

    • Two topics selected with definition and standard
    • Architecture / working principle and features
    • Applications and advantages / limitations
    • Comparison or concluding remarks