DATA COMMUNICATION Lecture-15

Recap of Lecture 14 Introduction to the Encoding Techniques Digital-To-Digital Encoding Types of Digital-To-Digital Encoding UniPolar Encoding Polar Encoding NRZ

Overview of Lecture 15 Types of Digital-To-Digital Encoding Polar Encoding Return to Zero (RZ) Encoding Biphase Encoding Bipolar Encoding

Conversion Methods

Types of Digital-to-Digital Encoding Digital/Digital Encoding Unipolar Polar Bipolar

Types of Polar Encoding

Return to Zero (RZ)

Biphase Encoding Best existing solution to the problem of Synchronization Signal changes at the middle of bit interval but does not stop at zero

Differential Manchester Biphase Encoding Biphase Encoding Differential Manchester Manchester

Manchester

Differential Manchester

Bipolar Encoding Like RZ, it uses three voltage levels: Unlike RZ, zero level is used to represent binary 0 Binary 1’s are represented by alternate positive and negative voltages

Bipolar Encoding

Alternate Mark Inversion (AMI) Simplest type of Bipolar Encoding Mark  Comes from Telegraphy (1) Alternate Mark Inversion means Alternate ‘1’ Inversion

Alternate Mark Inversion (AMI)

Bipolar 8 Zeros Substitution (B8ZS)

High Density Bipolar 3 (HDB3)

Summary Types of Digital-To-Digital Encoding Polar Encoding Return to Zero (RZ) Encoding Biphase Encoding Bipolar Encoding

Suggested Reading Section 5.1, “Data Communications and Networking” 2nd Edition by Behrouz A. Forouzan