1. Communication Modes
Communication modes define how data flows between two devices in a network or communication system.
2. Types of Communication
A. Simplex
- Definition: Data flows in one direction only.
- Example: A one-way street where cars only go in one direction.
- Key Features:
- Sender → Receiver.
- Receiver cannot send back any data.
- Use Cases:
- Television Broadcasts: TV station sends signals; viewers only receive.
- Radio Broadcasting.
B. Half-Duplex
- Definition: Data flows in both directions, but only one at a time.
- Example: A walkie-talkie where you “push-to-talk.”
- Key Features:
- Sender ↔ Receiver, but only one side communicates at a time.
- Requires a protocol to manage turns.
- Use Cases:
- Walkie-Talkies: One user speaks while the other listens.
- Shared Media Networks: Legacy Ethernet systems.
C. Full-Duplex
- Definition: Data flows in both directions at the same time.
- Example: A phone call where both parties can talk and listen simultaneously.
- Key Features:
- Sender ↔ Receiver communicate simultaneously.
- Faster and more efficient than half-duplex.
- Use Cases:
- Mobile Phones: Speak and hear in real time.
- Modern Ethernet Networks.
3. Key Comparisons
| Feature | Simplex | Half-Duplex | Full-Duplex |
|---|---|---|---|
| Data Flow | One Direction | Both Directions (One at a Time) | Both Directions (Simultaneously) |
| Communication | One-Way Only | Two-Way (Alternating) | Two-Way (Concurrent) |
| Speed | Slow | Moderate | Fast |
| Examples | TV, Radio | Walkie-Talkies | Phone Calls, Ethernet |
4. Quick Recap
- Simplex: One-way only (e.g., TV).
- Half-Duplex: Two-way, but one at a time (e.g., Walkie-Talkies).
- Full-Duplex: Two-way, simultaneously (e.g., Phones).
MCQ
1. What is Simplex Communication?
- A) A two-way communication system.
- B) Communication that occurs in one direction only.
- C) Data flow in alternate directions but one at a time.
- D) None of the above.
Answer: B
2. An example of Simplex communication is:
- A) Telephone call.
- B) Television broadcast.
- C) Walkie-talkie.
- D) Email communication.
Answer: B
3. Which type of communication allows data to flow in both directions, but only one direction at a time?
- A) Simplex.
- B) Half-duplex.
- C) Full-duplex.
- D) None of the above.
Answer: B
4. Walkie-talkies operate in which mode of communication?
- A) Simplex.
- B) Half-duplex.
- C) Full-duplex.
- D) All of the above.
Answer: B
5. Which communication mode allows simultaneous data flow in both directions?
- A) Simplex.
- B) Half-duplex.
- C) Full-duplex.
- D) None of the above.
Answer: C
6. Which of the following is an example of Full-duplex communication?
- A) Television broadcasting.
- B) Chat applications.
- C) Walkie-talkies.
- D) Public address system.
Answer: B
7. The primary distinction between Simplex and Half-duplex modes is:
- A) Simplex allows bidirectional communication; Half-duplex does not.
- B) Half-duplex allows bidirectional communication but not simultaneously; Simplex is unidirectional.
- C) Both allow simultaneous bidirectional communication.
- D) None of the above.
Answer: B
8. A telephone call is an example of which communication mode?
- A) Simplex.
- B) Half-duplex.
- C) Full-duplex.
- D) Multiplex.
Answer: C
9. In which communication mode is the entire bandwidth dedicated to a single direction at a time?
- A) Simplex.
- B) Half-duplex.
- C) Full-duplex.
- D) None of the above.
Answer: B
10. Which of these statements about Full-duplex communication is true?
- A) Data flows only in one direction.
- B) Data can flow in both directions but not at the same time.
- C) Data can flow in both directions simultaneously.
- D) None of the above.
Answer: C