Question 1(a) [3 marks]#
Differentiate Basic modes of Communication: Broad casting communication and Point to Point Communication.
Answer:
| Parameter | Broadcasting Communication | Point to Point Communication |
|---|---|---|
| Definition | One transmitter sends signals to multiple receivers simultaneously | One transmitter communicates with one specific receiver |
| Direction | Unidirectional (one-way) | Bidirectional (two-way) |
| Examples | TV, Radio, FM | Telephone, Mobile calls, Private networks |
| Privacy | Low (signal available to everyone in range) | High (dedicated connection between endpoints) |
| Efficiency | High for mass communication | Better for personal/private communication |
Mnemonic: “BDPEC” - Broadcasting Distributes to Public, Endpoints Connect in point-to-point
Question 1(b) [4 marks]#
Define: Bit Rate, Baud Rate, Bandwidth and Repeater Distance.
Answer:
| Term | Definition |
|---|---|
| Bit Rate | Number of binary bits transmitted per second (bps). Measures actual data transfer speed. |
| Baud Rate | Number of signal units or symbols transmitted per second. One symbol may contain multiple bits. |
| Bandwidth | Range of frequencies used by a signal, measured in Hertz (Hz). Determines maximum data capacity of a channel. |
| Repeater Distance | Maximum distance between repeaters in a communication system before signal degradation requires regeneration. |
Diagram:
graph LR
A[Signal] --> B[Bandwidth = Max Frequency - Min Frequency]
C[Bits] --> D[Bit Rate = Bits/Second]
E[Symbols] --> F[Baud Rate = Symbols/Second]
G[Distance] --> H[Repeater Distance = Max Distance Before Signal Regeneration]
Mnemonic: “BBRR” - “Better Bandwidth Requires Repeaters”
Question 1(c) [7 marks]#
Draw the block diagram of digital communication system. Explain the functions of each block in brief. State advantages and disadvantages of it.
Answer:
Block Diagram:
graph LR
A[Input Source] --> B[Source Encoder]
B --> C[Channel Encoder]
C --> D[Digital Modulator]
D --> E[Channel]
E --> F[Digital Demodulator]
F --> G[Channel Decoder]
G --> H[Source Decoder]
H --> I[Output]
Functions:
| Block | Function |
|---|---|
| Source Encoder | Converts analog signal to digital, removes redundancy, compresses data |
| Channel Encoder | Adds redundancy for error detection and correction |
| Digital Modulator | Converts digital data to suitable form for transmission (ASK, FSK, PSK, etc.) |
| Channel | Medium through which signal travels (wired/wireless) |
| Digital Demodulator | Extracts original digital data from received modulated signal |
| Channel Decoder | Detects and corrects errors using added redundancy |
| Source Decoder | Decompresses data and converts to original form |
Advantages and Disadvantages:
| Advantages | Disadvantages |
|---|---|
| Better noise immunity | Requires more bandwidth |
| Easier signal regeneration | Complex implementation |
| Secure transmission possible | Synchronization required |
| Integration with computers | Quantization errors |
| Better quality for long distance | Higher cost for simple applications |
Mnemonic: “SECDCSO” - “Secure Encoding Creates Digital Communication System Output”
Question 1(c) OR [7 marks]#
Justify the needs of multiplexing techniques for digital communication. Draw and explain Time Division multiplexing technique in brief. Discuss its merits and demerits.
Answer:
Need for Multiplexing:
| Need | Explanation |
|---|---|
| Channel Efficiency | Allows multiple signals on one channel, saving bandwidth |
| Cost Reduction | Reduces need for multiple transmission media |
| Infrastructure Utilization | Maximizes use of expensive infrastructure |
| Spectrum Conservation | Conserves limited frequency spectrum |
Time Division Multiplexing (TDM):
graph LR
A1[Input 1] --> M[Multiplexer]
A2[Input 2] --> M
A3[Input 3] --> M
A4[Input 4] --> M
M --> T[Transmission Channel]
T --> D[Demultiplexer]
D --> B1[Output 1]
D --> B2[Output 2]
D --> B3[Output 3]
D --> B4[Output 4]
Working: In TDM, each input signal gets a specific time slot. The multiplexer samples each input sequentially, combining them into a single high-speed data stream. At the receiver, the demultiplexer separates the stream back into original signals based on timing.
Merits and Demerits:
| Merits | Demerits |
|---|---|
| Efficient bandwidth usage | Requires synchronization |
| No guard bands needed | Complex buffering required |
| No cross-talk | Timing issues can cause errors |
| Flexible allocation | Unused slots waste capacity |
| Digital implementation | Higher data rate than individual channels |
Mnemonic: “TIME” - “Transmission Interleaves Multiple Endpoints”
Question 2(a) [3 marks]#
Differentiate: Coherent and Non-Coherent Detection Technique.
Answer:
| Parameter | Coherent Detection | Non-Coherent Detection |
|---|---|---|
| Phase Information | Uses phase information | Ignores phase information |
| Local Oscillator | Required | Not required |
| Complexity | More complex | Simpler |
| Performance | Better noise immunity | Less efficient in noise |
| Implementation | Difficult | Easier |
| Applications | High-quality systems | Low-cost systems |
Mnemonic: “PLCPIA” - “Phase Local Complex Performance Implementation Applications”
Question 2(b) [4 marks]#
Sketch the ASK, FSK, PSK and QPSK waveform for the data sequence 101100110110.
Answer:
Mnemonic: “AFPQ” - “Amplitude Frequency Phase Quadrature”
Question 2(c) [7 marks]#
Explain the principle of 16-QAM. Also explain constellation diagram and waveform for 16-QAM. Write its advantages and disadvantages.
Answer:
Principle of 16-QAM: 16-QAM (Quadrature Amplitude Modulation) combines amplitude and phase modulation to transmit 4 bits per symbol. It uses 16 different combinations of amplitude and phase, allowing higher data rates in the same bandwidth.
Constellation Diagram:
Waveform: The 16-QAM waveform varies in both amplitude (4 levels) and phase (4 phases), creating 16 unique symbols.
Advantages and Disadvantages:
| Advantages | Disadvantages |
|---|---|
| High spectral efficiency | Sensitive to noise and interference |
| Higher data rate | Requires higher SNR |
| Bandwidth efficient | Complex implementation |
| Better use of channel capacity | Susceptible to amplitude distortion |
Mnemonic: “SCHAP” - “Sixteen Combinations Have Amplitude and Phase”
Question 2(a) OR [3 marks]#
Compare: ASK and PSK
Answer:
| Parameter | ASK (Amplitude Shift Keying) | PSK (Phase Shift Keying) |
|---|---|---|
| Modulation Parameter | Amplitude | Phase |
| Noise Immunity | Poor | Good |
| Power Efficiency | Less efficient | More efficient |
| Bandwidth Efficiency | Lower | Higher |
| Implementation | Simple | More complex |
| BER Performance | Higher error rate | Lower error rate |
Mnemonic: “ANPBIP” - “Amplitude Noise Power Bandwidth Implementation Performance”
Question 2(b) OR [4 marks]#
Draw the block diagram of BPSK modulator and demodulator.
Answer:
BPSK Modulator:
graph LR
A[Binary Input] --> B[NRZ Encoder]
B --> C[Multiplier]
D[Carrier Generator] --> C
C --> E[BPSK Output]
BPSK Demodulator:
graph LR
A[BPSK Input] --> B[Multiplier]
C[Local Oscillator] --> D[Phase Synchronizer]
D --> B
B --> E[Low Pass Filter]
E --> F[Decision Device]
F --> G[Binary Output]
Mnemonic: “MNECO” - “Modulation Needs Encoding, Carriers, Oscillators”
Question 2(c) OR [7 marks]#
Explain QPSK generation and detection with the help of block diagram and waveform. Discuss its advantages and disadvantages.
Answer:
QPSK Generation Block Diagram:
graph LR
A[Binary Input] --> B[Serial to Parallel]
B -->|I-channel| C[Multiplier I]
B -->|Q-channel| D[Multiplier Q]
E[Carrier Generator] --> C
E --> F[90° Phase Shifter]
F --> D
C --> G[Adder]
D --> G
G --> H[QPSK Output]
QPSK Detection Block Diagram:
graph LR
A[QPSK Input] --> B[Multiplier I]
A --> C[Multiplier Q]
D[Local Oscillator] --> B
D --> E[90° Phase Shifter]
E --> C
B --> F[LPF I]
C --> G[LPF Q]
F --> H[Decision Device I]
G --> I[Decision Device Q]
H --> J[Parallel to Serial]
I --> J
J --> K[Binary Output]
QPSK Waveform: Each symbol in QPSK represents 2 bits, with 4 possible phase states (0°, 90°, 180°, 270°).
Advantages and Disadvantages:
| Advantages | Disadvantages |
|---|---|
| Twice the data rate of BPSK | More complex implementation |
| Same bandwidth as BPSK | Sensitive to phase errors |
| Good noise immunity | Requires carrier recovery |
| Spectral efficiency | More complex synchronization |
Mnemonic: “PACE” - “Phase Alteration Carries Extra data”
Question 3(a) [3 marks]#
State the features of RS-422.
Answer:
| Features of RS-422 |
|---|
| Differential signaling for noise immunity |
| Maximum data rate of 10 Mbps |
| Maximum cable length of 1200 meters |
| Multi-drop capability (1 driver, up to 10 receivers) |
| Balanced transmission line |
| Higher noise immunity than RS-232 |
Mnemonic: “DMMBHN” - “Differential Maximum Multi-drop Balanced Higher Noise-immunity”
Question 3(b) [4 marks]#
Define: Entropy, Information, Mutual Information and Probability.
Answer:
| Term | Definition |
|---|---|
| Entropy | Measure of uncertainty or randomness in a message source, calculated as H(X) = -∑p(x)log₂p(x) |
| Information | Reduction in uncertainty when a message is received, measured in bits |
| Mutual Information | Measure of dependency between two random variables, indicating how much information one variable contains about the other |
| Probability | Mathematical measure of likelihood that an event will occur, ranging from 0 (impossible) to 1 (certain) |
Diagram:
graph TD
A[Entropy of X: H(X)] --- C[Mutual Information: I(X;Y)]
B[Entropy of Y: H(Y)] --- C
C --- D[Measures shared information between X and Y]
Mnemonic: “EIMP” - “Entropy Information Measures Probability”
Question 3(c) [7 marks]#
Explain Huffman Code and Shannon-Fano code with suitable example.
Answer:
Huffman Code: Huffman coding assigns variable-length codes to symbols based on their frequencies, with shorter codes for more frequent symbols.
Example:
| Symbol | Frequency | Huffman Code |
|---|---|---|
| A | 45% | 0 |
| B | 25% | 10 |
| C | 15% | 110 |
| D | 10% | 1110 |
| E | 5% | 1111 |
Huffman Tree:
graph TD
A[100%] --> B[60%]
A --> C[A: 40%/0]
B --> D[30%]
B --> E[B: 30%/10]
D --> F[15%]
D --> G[C: 15%/110]
F --> H[D: 10%/1110]
F --> I[E: 5%/1111]
Shannon-Fano Code: Shannon-Fano algorithm recursively divides symbols into two groups of similar frequency, then assigns 0 to one group and 1 to the other.
Example:
| Symbol | Frequency | Shannon-Fano Code |
|---|---|---|
| A | 45% | 0 |
| B | 25% | 10 |
| C | 15% | 110 |
| D | 10% | 1110 |
| E | 5% | 1111 |
Shannon-Fano Tree:
graph TD
A[A,B,C,D,E] --> B[A/0]
A --> C[B,C,D,E]
C --> D[B/10]
C --> E[C,D,E]
E --> F[C/110]
E --> G[D,E]
G --> H[D/1110]
G --> I[E/1111]
Mnemonic: “FREDS” - “Frequency Reduces Encoding Digit Size”
Question 3(a) OR [3 marks]#
State the features of RS-232.
Answer:
| Features of RS-232 |
|---|
| Single-ended signaling |
| Maximum data rate of 20 kbps |
| Maximum cable length of 15 meters |
| Point-to-point communication (1 driver, 1 receiver) |
| Voltage levels: -15V to +15V |
| 25-pin or 9-pin DB connector standard |
Mnemonic: “SMPVD” - “Single Maximum Point-to-point Voltage DB-connector”
Question 3(b) OR [4 marks]#
What is channel capacity in terms of SNR? Explain its importance.
Answer:
Channel Capacity: The maximum rate at which information can be transmitted over a communication channel with an arbitrarily small probability of error.
Formula: C = B × log₂(1 + SNR)
Where:
- C = Channel capacity in bits per second
- B = Bandwidth in Hertz
- SNR = Signal-to-Noise Ratio
Importance:
| Importance of Channel Capacity |
|---|
| Sets theoretical limits for data transmission |
| Guides system design and optimization |
| Helps evaluate performance of communication systems |
| Determines required bandwidth for a given data rate |
| Informs coding techniques to approach capacity |
Diagram:
graph LR
A[Bandwidth] --> C[Channel Capacity]
B[SNR] --> C
C --> D[Maximum Achievable Data Rate]
Mnemonic: “BSNR” - “Bandwidth and SNR Need Relationship”
Question 3(c) OR [7 marks]#
Explain in detail any one error detection and error correction technique in digital communication.
Answer:
Hamming Code Error Detection and Correction
Hamming code is a linear error-correcting code that can detect and correct single-bit errors in data transmission.
Working Principle:
- Data bits are positioned at locations that are powers of 2 (1, 2, 4, 8, etc.)
- Parity bits are added at positions 1, 2, 4, 8, etc.
- Each parity bit checks specific data bits according to its position
- On receiving, parity checks identify error position
Example: 7-bit Hamming code (4 data bits, 3 parity bits)
| Position | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|
| Bit type | P₁ | P₂ | D₁ | P₄ | D₂ | D₃ | D₄ |
Parity Bit Calculation:
- P₁ checks bits 1, 3, 5, 7 (positions 1, 3, 5, 7)
- P₂ checks bits 2, 3, 6, 7 (positions 2, 3, 6, 7)
- P₄ checks bits 4, 5, 6, 7 (positions 4, 5, 6, 7)
Error Correction: If an error occurs, the parity checks will indicate the error position, which can then be flipped to correct the error.
Table: Error Position from Parity Check Results
| P₄ | P₂ | P₁ | Error Position |
|---|---|---|---|
| 0 | 0 | 0 | No error |
| 0 | 0 | 1 | Position 1 |
| 0 | 1 | 0 | Position 2 |
| 0 | 1 | 1 | Position 3 |
| 1 | 0 | 0 | Position 4 |
| 1 | 0 | 1 | Position 5 |
| 1 | 1 | 0 | Position 6 |
| 1 | 1 | 1 | Position 7 |
Mnemonic: “PECD” - “Parity Enables Correction of Data”
Question 4(a) [3 marks]#
Draw the block diagram of satellite communication and explain in brief.
Answer:
Satellite Communication Block Diagram:
graph TD
A[Ground Station 1] -->|Uplink| B[Satellite]
B -->|Downlink| C[Ground Station 2]
D[Transmitter] --> A
C --> E[Receiver]
Brief Explanation: Satellite communication involves transmitting signals from an Earth station to a satellite (uplink), which then amplifies and retransmits the signals back to Earth (downlink). The satellite acts as a repeater in space, enabling long-distance communication.
Key Components:
- Earth Stations: Transmit and receive signals
- Transponders: Receive, amplify, and retransmit signals
- Antennas: Transmit and receive electromagnetic waves
- Modems: Convert digital data to analog signals and vice versa
Mnemonic: “STAR” - “Satellite Transmits And Receives”
Question 4(b) [4 marks]#
Sketch the Unipolar NRZ, Polar RZ, Polar NRZ and AMI waveform for 10101101 data sequence.
Answer:
Mnemonic: “UPPA” - “Unipolar Polar Polar AMI”
Question 4(c) [7 marks]#
Explain data transmission techniques in details with suitable example for digital communication.
Answer:
Data Transmission Techniques:
| Technique | Description | Example |
|---|---|---|
| Serial Transmission | Data bits sent one after another over a single channel | USB, UART communication |
| Parallel Transmission | Multiple bits sent simultaneously over multiple channels | Printer ports, SCSI |
| Synchronous Transmission | Data sent in continuous stream with timing signals | Ethernet, HDLC |
| Asynchronous Transmission | Data sent with start/stop bits as timing references | RS-232, UART |
| Simplex | One-way communication | TV broadcasting |
| Half-Duplex | Two-way communication, one direction at a time | Walkie-talkie |
| Full-Duplex | Two-way simultaneous communication | Telephone calls |
Serial Transmission Example:
Parallel Transmission Example:
Mnemonic: “SPASH” - “Serial Parallel Asynchronous Synchronous Half-duplex”
Question 4(a) OR [3 marks]#
Interpret the aspects of spread spectrum techniques.
Answer:
Spread Spectrum Techniques:
| Aspect | Interpretation |
|---|---|
| Bandwidth Spreading | Signal spread over a wider bandwidth than required |
| Security | Difficult to intercept or jam due to spreading |
| Noise Immunity | Resistant to narrowband interference |
| Multiple Access | Allows multiple users to share same frequency band |
| Low Power Density | Signal power spread across wide band, appearing as noise |
Diagram:
graph LR
A[Narrow Band Signal] --> B[Spreading]
B --> C[Wideband Spread Signal]
D[Spreading Code] --> B
Mnemonic: “BSNML” - “Bandwidth Security Noise Multiple Low-power”
Question 4(b) OR [4 marks]#
Write a short note on probability and discuss its properties for digital communication.
Answer:
Probability in Digital Communication: Probability theory provides the mathematical foundation for analyzing performance, error rates, and reliability of digital communication systems.
Properties of Probability:
| Property | Description | Relevance in Digital Communication |
|---|---|---|
| Range | 0 ≤ P(E) ≤ 1 | Sets bounds for error probability |
| Certainty | P(S) = 1 for sample space S | Total probability of all possible outcomes |
| Additivity | P(A∪B) = P(A) + P(B) for disjoint events | Calculating overall system error rates |
| Conditional Probability | P(A|B) = P(A∩B)/P(B) | Useful for channel modeling |
| Independence | P(A∩B) = P(A)×P(B) | Analyzing uncorrelated noise sources |
Applications in Digital Communication:
- Bit Error Rate calculation
- Signal detection theory
- Channel capacity estimation
- Coding efficiency analysis
Mnemonic: “RACIC” - “Range Additivity Certainty Independence Conditional”
Question 4(c) OR [7 marks]#
Explain Data transmission mode in details with example.
Answer:
Data Transmission Modes:
| Mode | Description | Diagram | Example |
|---|---|---|---|
| Simplex | One-way communication only. Transmitter can only send, receiver can only receive. | graph LR; A[Transmitter] -->|One-way| B[Receiver] | TV broadcasting, Radio |
| Half-Duplex | Two-way communication, but only one direction at a time. | graph LR; A[Device A] -->|Time 1| B[Device B]; B -->|Time 2| A | Walkie-talkie, CB radio |
| Full-Duplex | Two-way simultaneous communication. | graph LR; A[Device A] -->|Channel 1| B[Device B]; B -->|Channel 2| A | Telephone, Mobile calls |
Example of Half-Duplex Communication:
Example of Full-Duplex Communication:
Mnemonic: “SHF” - “Simplex Half Full” or “Stop, Halt, Flow”
Question 5(a) [3 marks]#
Explain Edge Computing in detail.
Answer:
Edge Computing: Edge computing is a distributed computing paradigm that brings computation and data storage closer to the location where it is needed to improve response times and save bandwidth.
Key Aspects:
| Aspect | Description |
|---|---|
| Decentralization | Processing at network edge instead of central cloud |
| Reduced Latency | Faster response due to proximity to data source |
| Bandwidth Efficiency | Less data sent to cloud, reducing network congestion |
| Local Data Processing | Data processed near collection point |
| Improved Security | Sensitive data remains local, reducing exposure |
| Reliability | Continues to function during cloud connectivity issues |
Diagram:
graph LR
A[IoT Devices] --> B[Edge Computing]
B --> C[Local Processing]
B --> D[Local Storage]
B --> E[Cloud]
E --> F[Central Storage & Processing]
Mnemonic: “DRBLES” - “Decentralized Reduces Bandwidth, Latency, Exposure, Strengthens reliability”
Question 5(b) [4 marks]#
Enlist the features of 5G Technology in data communication.
Answer:
| Features of 5G Technology |
|---|
| High Data Rates (up to 20 Gbps peak) |
| Ultra-Low Latency (1 ms or less) |
| Massive Device Connectivity (1 million devices per km²) |
| Network Slicing (customized virtual networks) |
| Beamforming (directed signal transmission) |
| Millimeter Wave Spectrum (24-100 GHz) |
| Enhanced Mobile Broadband (eMBB) |
| Ultra-Reliable Low-Latency Communication (URLLC) |
Diagram:
graph TD
A[5G Technology] --> B[High Data Rates]
A --> C[Ultra-Low Latency]
A --> D[Massive Connectivity]
A --> E[Network Slicing]
A --> F[Three Main Use Cases]
F --> G[eMBB]
F --> H[URLLC]
F --> I[mMTC]
Mnemonic: “HUMBLE-MN” - “High-speed Ultra-low-latency Massive Beamforming Low-latency Enhanced Millimeter Network”
Question 5(c) [7 marks]#
Write a details note on Data communication including its characteristics and components.
Answer:
Data Communication: Data communication is the process of transferring digital information between two or more points.
Characteristics of Data Communication:
| Characteristic | Description |
|---|---|
| Delivery | System must deliver data to correct destination |
| Accuracy | System must deliver data accurately, without errors |
| Timeliness | System must deliver data in a timely manner |
| Jitter | System must maintain consistent timing between data arrivals |
| Security | System must protect data from unauthorized access |
Components of Data Communication:
| Component | Description |
|---|---|
| Message | The information (data) to be communicated |
| Sender | Device that sends the data message |
| Receiver | Device that receives the message |
| Transmission Medium | Physical path by which message travels |
| Protocol | Set of rules governing data communication |
Data Communication Model:
graph LR
A[Sender] --> B[Encoder]
B --> C[Transmission Medium]
C --> D[Decoder]
D --> E[Receiver]
F[Protocol] --> A
F --> B
F --> C
F --> D
F --> E
Data Communication Types:
| Type | Description |
|---|---|
| Analog | Continuous signal that varies in amplitude or frequency |
| Digital | Discrete signal represented by binary digits (0s and 1s) |
| Parallel | Multiple bits transmitted simultaneously on separate channels |
| Serial | Bits transmitted sequentially on a single channel |
Mnemonic: “DATJS-MSRTP” - “Delivery Accuracy Timeliness Jitter Security - Message Sender Receiver Transmission Protocol”
Question 5(a) OR [3 marks]#
Identify and write privacy consideration in Data communication.
Answer:
Privacy Considerations in Data Communication:
| Privacy Consideration | Description |
|---|---|
| Data Encryption | Protecting data during transmission using encryption algorithms |
| Access Control | Ensuring only authorized users can access communication systems |
| Authentication | Verifying the identity of users and devices |
| Data Minimization | Collecting only necessary data to minimize privacy risks |
| Secure Protocols | Using communication protocols with built-in security features |
| End-to-End Security | Ensuring data is protected throughout the entire communication path |
Diagram:
graph TD
A[Privacy in Data Communication] --> B[Data Encryption]
A --> C[Access Control]
A --> D[Authentication]
A --> E[Data Minimization]
A --> F[Secure Protocols]
A --> G[End-to-End Security]
Mnemonic: “DAAESE” - “Data is Authenticated, Accessed, Encrypted Securely End-to-end”
Question 5(b) OR [4 marks]#
What is block chain in communication security? Enlist its features.
Answer:
Blockchain in Communication Security: Blockchain is a distributed ledger technology that provides secure, tamper-proof record-keeping for data communication through cryptographic linking of data blocks.
Features of Blockchain:
| Feature | Description |
|---|---|
| Decentralization | No central authority; distributed across network nodes |
| Immutability | Once recorded, data cannot be altered without consensus |
| Transparency | All transactions visible to authorized participants |
| Cryptographic Security | Data secured using advanced cryptographic techniques |
| Consensus Mechanism | Network agrees on validity of transactions |
| Smart Contracts | Self-executing contracts with terms directly written in code |
| Distributed Storage | Data stored across multiple nodes, preventing single point of failure |
Diagram:
graph LR
A[Block 1] -->|Hash Link| B[Block 2]
B -->|Hash Link| C[Block 3]
C -->|Hash Link| D[Block 4]
A --> A1[Transactions]
A --> A2[Hash]
A --> A3[Previous Hash]
B --> B1[Transactions]
B --> B2[Hash]
B --> B3[Previous Hash]
Mnemonic: “DITCSD” - “Decentralized Immutable Transparent Cryptographic Secure Distributed”
Question 5(c) OR [7 marks]#
Write and illustrate different communication ports: USB, HDMI, RCA and Ethernet.
Answer:
Communication Ports:
- USB (Universal Serial Bus):
Features:
- Data transfer, power delivery, and device connection
- Versions: USB 1.0 to USB 4.0
- Speed: Up to 40 Gbps (USB4)
- Hot-swappable
- Supports up to 127 devices in cascade
- HDMI (High-Definition Multimedia Interface):
Features:
- Digital audio/video transmission
- Versions: HDMI 1.0 to HDMI 2.1
- Resolution support: Up to 10K
- Bandwidth: Up to 48 Gbps (HDMI 2.1)
- HDCP (High-bandwidth Digital Content Protection)
- CEC (Consumer Electronics Control) for device control
- RCA (Radio Corporation of America):
Features:
- Analog audio/video transmission
- Color-coded connectors (Red, White, Yellow)
- Used for composite video and stereo audio
- Simple connection but limited quality
- No digital content protection
- Being phased out by digital standards
- Ethernet (RJ-45):
Features:
- Network connectivity
- Standards: 10BASE-T to 10GBASE-T
- Speed: 10 Mbps to 10 Gbps
- Uses twisted-pair cabling (Cat5e, Cat6, Cat6a)
- Supports Power over Ethernet (PoE)
- Base communication for TCP/IP networks
- Maximum cable length: 100 meters
Comparison Table:
| Port | Type | Data Type | Max Speed | Power Delivery | Max Length |
|---|---|---|---|---|---|
| USB | Digital | Data/Power | 40 Gbps | Yes (100W) | 5m |
| HDMI | Digital | Audio/Video | 48 Gbps | Limited | 15m |
| RCA | Analog | Audio/Video | Low | No | 10m |
| Ethernet | Digital | Network Data | 10 Gbps | Yes (PoE) | 100m |
Mnemonic: “UHRE” - “USB Handles Rapid Ethernet, HDMI Delivers Rich Entertainment”