Computer Networks

1. Telephone

2. Full-duplex

2.1. Both direction

3. Introduction

3.1. Transmission modes

3.1.1. Serial

3.1.1.1. One bit at a time

3.1.1.2. Typically used for long distance

3.1.1.3. Cheap too

3.1.2. Parallel

3.1.2.1. More than one bit simulaneously

3.1.2.2. Costly and complex

3.1.3. Unreliable for data communication

3.1.4. Simplex

3.1.4.1. Open loop

3.1.4.1.1. Unidirectional

3.1.4.2. TV broadcast

3.1.5. Half-duplex

3.1.5.1. One direction at a time

3.1.5.2. Bidirectional

3.2. Speed

3.2.1. Baud

3.2.2. BPS

3.3. Synchronization

3.3.1. Asynchronous

3.3.1.1. Not coordinated in time

3.3.1.2. Use of start and stop bit

3.3.1.3. Simpler and cheaper

3.3.2. Synchronous

3.3.2.1. Coordinated in time

3.3.2.2. No use of start and stop bit

3.3.2.3. Costlier