IOE PapersTU
PYQs & Syllabus Archive
ENCT 253Bachelor in Computer Engineering · Semester 42 Papers Available

Data Communication

Past examination question papers and complete curriculum syllabus for Data Communication (ENCT 253), Bachelor in Computer Engineering Semester 4 under Institute of Engineering (IOE), Tribhuvan University.

Past Question Papers (PDF)

Switch tabs to view different exam papers
Available Papers:

4th-sem_Data Communication.pdf

IOE Past Examination Paper

Download PDF
Served via fast CDN. Read in full view or download for offline study.
Drive Mirror ↗Direct Download ↓

Document information: This past examination paper is identified as an IOE/TU academic document and was cataloged from a public Google Drive archive. This independent website did not create the examination paper and is not affiliated with TU or IOE.

Rights holders can request correction or removal by emailing subeshgaming@gmail.com with this page URL and supporting details.

Most Frequently Asked Questions

Top recurring IOE board exam questions for Data Communication with verified mark schemes, formula notation, and recurrence frequency.

Showing 30 of 30 top repeated questions

Introduction

3 Questions
#1Repeated 4 Times[8 Marks]Introduction
Describe transmission impairments in data communication systems (attenuation, distortion, and noise). State and explain Shannon-Hartley channel capacity theorem and Nyquist bit rate formula with their practical implications.
Appeared in:2080 Bhadra2075 Ashwin2072 Chaitra2070 Chaitra
#2Repeated 2 Times[6 Marks]Introduction
State Nyquist Bit Rate formula and Shannon Channel Capacity theorem. A telephone line has a bandwidth of $3.1\text{ kHz}$ and a signal-to-noise ratio of $30\text{ dB}$. Calculate the theoretical maximum channel capacity.
Appeared in:2082 Kartik2081 Chaitra
#3Repeated 2 Times[6 Marks]Introduction
Explain transmission impairments: Attenuation, Distortion, and Noise (Thermal noise, Intermodulation noise, Crosstalk, Impulse noise).
Appeared in:2082 Shrawan2080 Chaitra

Data Communication Fundamentals

9 Questions
#1Repeated 5 Times[8 Marks]Data Communication Fundamentals
Explain the operation of Cyclic Redundancy Check (CRC). Given data bit stream $D = 1010001101$ and divisor polynomial $G(x) = x^4 + x^2 + 1$, determine the CRC code (remainder) and transmitted codeword. Show error detection when one bit is corrupted.
Appeared in:2080 Bhadra2080 Baishakh2078 Bhadra2075 Chaitra2075 Ashwin
#2Repeated 4 Times[6 Marks]Data Communication Fundamentals
Distinguish between Energy signal and Power signal with examples. Check whether the unit step signal $x(t) = u(t)$ and rectangular pulse are energy or power signals.
Appeared in:2080 Baishakh2075 Chaitra2075 Ashwin2072 Chaitra
#3Repeated 4 Times[8 Marks]Data Communication Fundamentals
Define LTI system. Compute the convolution integral $y(t) = x(t) * h(t)$ between two continuous-time signals where $x(t) = e^{-at}u(t)$ and $h(t) = u(t)$ ($a > 0$). Sketch the resulting output signal.
Appeared in:2080 Baishakh2078 Bhadra2075 Ashwin2071 Chaitra
#4Repeated 4 Times[8 Marks]Data Communication Fundamentals
What are Hamming codes? Explain how parity bits are placed and calculated in a $(7, 4)$ Hamming code. If the received word is $r = 1010110$, detect and correct the single-bit error using syndrome decoding.
Appeared in:2078 Bhadra2075 Ashwin2072 Chaitra2070 Chaitra
#5Repeated 4 Times[8 Marks]Data Communication Fundamentals
What are Linear Block Codes? Given a $(6, 3)$ linear block code with generator matrix $G$, find all valid codewords, parity check matrix $H$, minimum Hamming distance $d_{min}$, and error detecting/correcting capabilities.
Appeared in:2078 Bhadra2075 Ashwin2072 Chaitra2071 Chaitra
#6Repeated 4 Times[8 Marks]Data Communication Fundamentals
Where are convolutional codes used? Explain a rate $r = 1/2$, constraint length $K = 3$ convolutional encoder with state diagram, tree diagram, and trellis diagram. Explain how the Viterbi algorithm performs decoding.
Appeared in:2080 Baishakh2078 Bhadra2075 Ashwin2074 Chaitra
#7Repeated 4 Times[8 Marks]Data Communication Fundamentals
State the properties of Continuous-Time Fourier Transform (CTFT). Find the Fourier transform of the double exponential pulse signal $x(t) = e^{-a|t|}$ ($a > 0$) and plot its magnitude spectrum.
Appeared in:2078 Bhadra2075 Ashwin2072 Chaitra2068 Chaitra
#8Repeated 2 Times[8 Marks]Data Communication Fundamentals
Given the dataword $100100$ and generator polynomial $G(x) = x^3 + x^2 + 1$. Generate the CRC codeword. At the receiver, verify if the received codeword has errors if bit 3 is inverted.
Appeared in:2082 Kartik2081 Chaitra
#9Repeated 2 Times[8 Marks]Data Communication Fundamentals
Explain Hamming code error correction. Construct a single-bit error correcting Hamming code for the 4-bit data word $1101$ and explain how an error at bit 5 is detected and corrected.
Appeared in:2082 Kartik2080 Chaitra

Transmission Media and Data Compression

7 Questions
#1Repeated 5 Times[8 Marks]Transmission Media and Data Compression
Write down the binary Huffman Coding Algorithm clearly. Given a message source emitting symbols with probabilities $P = [0.35, 0.25, 0.15, 0.10, 0.08, 0.07]$, construct the Huffman tree, determine codeword for each symbol, average code length, source entropy $H(X)$, and coding efficiency.
Appeared in:2080 Baishakh2078 Bhadra2075 Ashwin2074 Chaitra2072 Chaitra
#2Repeated 4 Times[8 Marks]Transmission Media and Data Compression
Differentiate between Circuit Switching and Packet Switching. Contrast Datagram packet switching with Virtual Circuit packet switching with respect to setup phase, routing, and header overhead.
Appeared in:2080 Baishakh2075 Ashwin2072 Chaitra2069 Chaitra
#3Repeated 3 Times[6 Marks]Transmission Media and Data Compression
Compare the transmission characteristics and performance (bandwidth, attenuation, immunity to EMI, and cost) of Twisted Pair cable, Coaxial cable, and Optical Fiber cable.
Appeared in:2075 Ashwin2072 Chaitra2070 Chaitra
#4Repeated 2 Times[6 Marks]Transmission Media and Data Compression
Compare guided media (Twisted Pair, Coaxial Cable, Optical Fiber) in terms of bandwidth, attenuation, and EMI immunity. Explain step-index vs graded-index optical fibers.
Appeared in:2082 Kartik2079 Baishakh
#5Repeated 2 Times[6 Marks]Transmission Media and Data Compression
Compare Circuit Switching, Packet Switching (Datagram vs Virtual Circuit), and Message Switching in terms of setup delay, bandwidth utilization, and reliability.
Appeared in:2082 Shrawan2081 Chaitra
#6Repeated 2 Times[8 Marks]Transmission Media and Data Compression
Define entropy and information capacity. Given a discrete memoryless source with symbols $S_1, S_2, S_3, S_4, S_5$ with probabilities $0.4, 0.2, 0.2, 0.1, 0.1$. Construct Huffman code and calculate average code length and coding efficiency.
Appeared in:2082 Kartik2081 Chaitra
#7Repeated 2 Times[8 Marks]Transmission Media and Data Compression
Encode the message 'ABRACADABRA' using Lempel-Ziv-Welch (LZW) compression algorithm. Show the initial dictionary, generated output tokens, and updated dictionary entries.
Appeared in:2081 Chaitra2079 Chaitra

Signal Encoding Technique

7 Questions
#1Repeated 4 Times[8 Marks]Signal Encoding Technique
Encode the bit stream `1010011001` using NRZ-L, NRZ-I, RZ, Manchester, Differential Manchester, and Bipolar AMI schemes. Explain DC component and baseline wandering.
Appeared in:2080 Baishakh2075 Ashwin2074 Chaitra2072 Chaitra
#2Repeated 4 Times[8 Marks]Signal Encoding Technique
Explain the working principle of Pulse Code Modulation (PCM). Detail sampling (Nyquist rate), uniform vs non-uniform quantization, companding ($\mu$-law and A-law), and PCM frame format.
Appeared in:2080 Bhadra2078 Bhadra2075 Ashwin2072 Chaitra
#3Repeated 3 Times[6 Marks]Signal Encoding Technique
Encode the sequence `111000000000000011` using B8ZS and HDB3 scrambling techniques. Why is scrambling necessary in digital transmission?
Appeared in:2080 Baishakh2078 Bhadra2076 Ashwin
#4Repeated 2 Times[8 Marks]Signal Encoding Technique
Compare line coding schemes: Unipolar, Polar (NRZ-L, NRZ-I, RZ), Bipolar (AMI), and Biphase (Manchester, Differential Manchester) in terms of DC component, self-synchronization, and bandwidth requirements.
Appeared in:2082 Kartik2081 Chaitra
#5Repeated 2 Times[8 Marks]Signal Encoding Technique
Explain Pulse Code Modulation (PCM) system with a block diagram. Explain Sampling, Quantization, and Encoding. Derive the expression for Signal-to-Quantization Noise Ratio ($SQNR$) for sinusoidal input.
Appeared in:2082 Kartik2080 Chaitra
#6Repeated 2 Times[8 Marks]Signal Encoding Technique
Explain Delta Modulation (DM) and Adaptive Delta Modulation (ADM). Explain Slope Overload Distortion and Granular Noise in DM.
Appeared in:2081 Chaitra2079 Chaitra
#7Repeated 2 Times[8 Marks]Signal Encoding Technique
Explain Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), Phase Shift Keying (PSK), and Quadrature Phase Shift Keying (QPSK). Draw constellation diagrams for QPSK and 16-QAM.
Appeared in:2082 Kartik2081 Chaitra

Multiplexing and Switching

4 Questions
#1Repeated 5 Times[8 Marks]Multiplexing and Switching
What is multiplexing? Compare Synchronous TDM with Statistical (Asynchronous) TDM. Describe Frequency Division Multiplexing (FDM) and Wavelength Division Multiplexing (WDM).
Appeared in:2080 Baishakh2078 Bhadra2075 Ashwin2074 Chaitra2072 Chaitra
#2Repeated 4 Times[8 Marks]Multiplexing and Switching
Explain the working principle of Spread Spectrum. Differentiate between Frequency Hopping Spread Spectrum (FHSS) and Direct Sequence Spread Spectrum (DSSS) with waveforms and block diagrams.
Appeared in:2080 Baishakh2078 Bhadra2076 Chaitra2073 Shrawan
#3Repeated 2 Times[8 Marks]Multiplexing and Switching
Differentiate between Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), and Wavelength Division Multiplexing (WDM). Explain Synchronous TDM vs Statistical TDM.
Appeared in:2082 Kartik2080 Chaitra
#4Repeated 2 Times[8 Marks]Multiplexing and Switching
Explain Spread Spectrum communication. Differentiate between Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) with block diagrams.
Appeared in:2081 Chaitra2078 Bhadra

Curriculum Syllabus & Course Topics

Sourced from TU curriculum portal
Full Syllabus (PDF)
Chapter-wise Units & Micro-Syllabus Topics (6 Units)

  1. 1. Introduction

    • 1.1Analog data communication, data representation, data flows
    • 1.2Evolution of data communication
    • 1.3A communication model, data communication model
    • 1.4Networks (LAN, WAN), simplified network architecture, the OSI model
    • 1.5Data communication and networking for today enterprise

  2. 2. Data Communication Fundamentals

    • 2.1Analog and digital data
    • 2.2Analog signals, periodic and aperiodic signals, periodic signals characteristics (Time, frequency domain)
    • 2.3Introduction to Fourier series representation of periodic signal, Fourier transform representation of aperiodic signals, digital signals and its characteristics
    • 2.4Analog and digital transmission, transmission mode, transmission impairments (Attenuation, distortion, noise)
    • 2.5Data rate limits channel capacity, Nyquist bandwidth, Shannon capacity formula
    • 2.6Performance of network (Bandwidth, throughput, latency, jitter)

  3. 3. Transmission Media and Data Compression

    • 3.1Guided transmission media: Co-axial cable, twisted pair, optical fiber
    • 3.2Unguided transmission media: Radio waves, microwaves, infrared
    • 3.3Antenna basics, satellite communication, Bluetooth, Wi-Fi
    • 3.4Wireless propagation (Introduction to groundwave propagation, sky wave propagation and line of sight propagation), frequency bands
    • 3.5Error detection and correction: Parity, check sum, cyclic redundancy check, hamming code
    • 3.6Data compression: Lossy and lossless

  4. 4. Signal Encoding Technique

    • 4.1Analog data, analog signals: Modulation and its need, AM, FM, PM
    • 4.2Analog data, digital signals: PAM, PWM, PPM, PCM, DPCM, DM
    • 4.3Digital data, analog signal: ASK, FSK, PSK, QPSK, QAM
    • 4.4Digital data, digital signal: RZ, NRZ, AMI, Manchester, differential Manchester, B8ZS, HDB3 for data transmission

  5. 5. Multiplexing and Switching

    • 5.1Access introduction to multiplexing, application of multiplexing
    • 5.2Frequency division multiple
    • 5.3Time division multiple access
    • 5.4Asymmetric digital subscriber line, XDSL
    • 5.5Spread spectrum: DHSS, FHSS, CDMA
    • 5.6Intro switched communication network, connection oriented and connectionless
    • 5.7Switching devices: Types, importance and application
    • 5.8Circuit switching network: Circuit switching concepts, message switching
    • 5.9Packet switching: Virtual switching, datagram switching

  6. 6. Cellular Wireless Communications and Latest Trends

    • 6.1Overview of 1G, 2G, 3G and 4G
    • 6.2Cellular technology fundamental terminology: Cell, frequency-reuse, cluster, adjacent cell interference, co-channel interference, handoff strategies, architecture of GSM basics
    • 6.3Introduction to 5G networks, software defined networking, IOT communication, cloud computing and virtualization in data communication

Examination Scheme & Marks Distribution

Evaluation Structure

  • Final Board Theory Exam: 60 Marks (Pass mark: 24)
  • Internal Assessment: 40 Marks (Pass mark: 16)
  • Practical / Lab Exam: 25 or 50 Marks (Continuous lab evaluation + viva, where applicable)

* This is the general current IOE 60/40 scheme; verify course-specific details in the syllabus above.

Exam Preparation Guidelines

  • Review the 2 available past examination papers to identify recurring patterns, core problem types, and chapter weightage.
  • Cross-reference key answers with official syllabus units, standard textbooks, and lecture notes.
  • Structure answers with labeled diagrams, concise bullet points, and highlight final answers in numerical solutions.

Frequently Asked Questions (Data Communication)

Q: How can I download Data Communication past question papers?

You can preview or download the Data Communication question papers (PDF) directly using the built-in viewer on this page with zero redirects or paywalls.

Q: What is the pass mark for Data Communication?

The general current scheme is a 60-mark final theory exam and a 40-mark internal assessment, with pass marks of 24 and 16. Verify the course-specific syllabus above.

Q: Where can I find the complete syllabus for this subject?

The available chapter-wise syllabus and topic breakdown is indexed in the Syllabus section above, with links to the curriculum PDF source.

Authentic IOE Past Papers
Free Direct PDF Download
Curriculum Syllabus & Marking Scheme