CS601 - Data Communication - Lecture Handout 20

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Related Content: CS601 - VU Lectures, Handouts, PPT Slides, Assignments, Quizzes, Papers & Books of Data Communication

Introduction

Q: How do we relay encoded data from the generating device to the next device?

A: Interface

  • Defined by several popular standards
  • Physical layer of the OSI model
  • Mechanical/electrical/functional specifications

Digital Data Transmission

Do we send one bit at a time or do we group bits into larger groups and if so, How?

Digital Data Transmission

Parallel Transmission

  • Binary data consisting of 1s and 0s may be organized into groups of ‘n’ bits each
  • By grouping we can send data ‘n’ bits at a time instead of one bit

Parallel Transmission

Serial Transmission

  • One bit follows another, so we need only one channel rather than ‘n’ to transmit data between two devices
  • Conversion devices are required at the interface

Serial Transmission

Advantage

  • COST

Types of Serial Transmission

There are two types of Serial Transmission:

  • Asychronous Transmission
  • Synchronous Transmission

Asynchronous Transmission

  • It is so named because the timing of the signal is unimportant. Instead information is received and translated by agreed upon patterns
  • Start and Stop Bits

Asynchronous Transmission

Asynchronous Transmission

Advantages

  • Cheap
  • Effective

Disadvantages

  • Slow

Synchronous Transmission

Data is transmitted as an unbroken string of 1’s and 0’s and the receiver separates that string into the bytes or characters it need to reconstruct the information

Synchronous Transmission

Synchronous Transmission

Advantage

  • Speed

Summary

Introduction to Interfaces

  • Digitl Data Transmission
  • Parallel Transmission
  • Serial Transmission
  • Asynchronous Transmission
  • Synchronous Transmission

Reading Sections

  • Section 6.1,6.2, “Data Communications and Networking” 4th Edition by Behrouz A. Forouzan