---
title: "Types of data transmission technology"
subject: "Data Communication"
chapter: 1
key: "semester_5/data_communication:data-transmission-technologies"
source: https://www.bctengineer.com/q/semester_5/data_communication/data-transmission-technologies
site: BCT Engineering
---

# Types of data transmission technology

Data Communication · Chapter 1: Introduction

- Asked in: 2079 Baisakh, 4 marks
- Video: [Data Transmission in Computer Networks | Learn Coding](https://www.youtube.com/watch?v=seG-aeL3LdA) — Learn Coding
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/data_communication/data-transmission-technologies
- Whole chapter: https://www.bctengineer.com/md/semester_5/data_communication/chapter-1

## Question

What are the different types of data transmission technology?

## Short answer

Data transmission types: by direction (simplex, half-duplex, full-duplex); by number of lines (serial, parallel); by timing (asynchronous with start/stop bits, synchronous with clock); by signal (baseband digital, broadband analog); and by switching (circuit, packet, message).

## Answer

Data transmission technologies are classified by how bits are sent over the medium.

#### 1. Based on direction
- **Simplex**: one direction only (keyboard to computer, radio broadcast).
- **Half duplex**: both directions but one at a time (walkie-talkie).
- **Full duplex**: both directions at the same time (telephone).

#### 2. Based on the number of lines
- **Serial transmission**: bits are sent one after another over a single line. Cheap, used for long distance (USB, RS-232).
- **Parallel transmission**: several bits are sent together on separate lines (printer port, internal buses). Fast, but costly and has skew over distance.

#### 3. Based on timing
- **Asynchronous**: each character is framed by start and stop bits; no common clock.
- **Synchronous**: a continuous block of data with a common clock; faster, less overhead.

#### 4. Based on signal type
- **Baseband (digital) transmission**: the digital signal is placed directly on the line using line coding.
- **Broadband (analog) transmission**: the data modulates a carrier (ASK, FSK, PSK, QAM).

#### 5. Based on switching
- Circuit switching, packet switching and message switching.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which is half duplex?
   A. Radio broadcast
   B. Telephone call
   C. Keyboard to computer
   D. Walkie-talkie
   Answer: D. Half duplex allows both directions but one at a time. (Key point: Half duplex)

2. Why is serial transmission used for long distances?
   A. It is cheap, using one line, and avoids skew
   B. It sends many bits at once
   C. It needs no cable
   D. It is always faster than parallel
   Answer: A. Parallel is fast but costly and suffers skew over distance. (Key point: Serial vs parallel)

3. What marks each character in asynchronous transmission?
   A. A common clock
   B. Start and stop bits
   C. Sync flags per frame
   D. Header and trailer of a block
   Answer: B. Asynchronous has no common clock and frames each character. (Key point: Asynchronous)

4. In broadband transmission the data
   A. is placed directly on the line using line coding
   B. is switched by circuits
   C. modulates a carrier (ASK, FSK, PSK, QAM)
   D. is sent in parallel
   Answer: C. Baseband puts digital signal directly on the line. (Key point: Baseband vs broadband)

## Related in Data Communication

- [Transmission impairments](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Atransmission-impairments) — Data Communication, chapter 1, asked 6×
- [Transmission channels; sync vs async](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Atransmission-modes) — Data Communication, chapter 1
- [Transmission impairments; attenuation of cable](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Aattenuation-cable-numeric) — Data Communication, chapter 1
- [Guided vs unguided transmission media](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Aguided-vs-unguided-media) — Data Communication, chapter 4
- [Optical fiber vs satellite transmission](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Aoptical-fiber-vs-satellite) — Data Communication, chapter 4
- [Transmission characteristics of guided media](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Aguided-media-transmission-characteristics) — Data Communication, chapter 4

## Related in other subjects

- [Error detection in serial data transmission](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Aserial-error-detection) — Instrumentation II, chapter 3, asked 2×
- [Synchronous vs asynchronous serial transmission](https://www.bctengineer.com/question.md?key=semester_4%2Fmicroprocessor%3Async-async-serial) — Microprocessor, chapter 4, asked 3×
- [Character transmission time at 1200 baud](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Abaud-time-1200) — Instrumentation II, chapter 3, asked 2×
- [CVT and dual clutch transmission](https://www.bctengineer.com/question.md?key=semester_5%2Fautomotive_technology%3Acvt-dct-short-notes) — Automotive Technology, chapter 5