ASM551/OSM554

Chapter 1

Introduction to Data Communications

Understand the difference between data communications Understand the difference between data communications and telecommunications.and telecommunications.

List the components of a data communications system.List the components of a data communications system.

Understand the needs for a network and its criteria. Understand the needs for a network and its criteria.

OBJECTIVES

Understand the data communications system effectiveness.Understand the data communications system effectiveness.

Understand the different types of network.Understand the different types of network.

Understand the difference between analog and digital data.Understand the difference between analog and digital data.

• Telecommunications is the transmission of data, or information, over a distance.

• Telecommunications is the communication by electrical, electromagnetic, or photonic means, over a distance.

• Eg: Telephony technologies - Mobile phones, land

lines, satellite phones and voice over Internet protocol (VoIP)

Radio, television and networks.

DATA COMMUNICATION VS TELECOMUNICATION

• A subset of telecommunication involving the transmission of data to and from computers and components of computer systems.

• Data communications is different from telecommunications in that it is a specialized function

• More specifically data communication is transmitted via mediums such as wires, coaxial cables, fiber optics, or radiated electromagnetic waves such as broadcast radio, infrared light, microwaves, and satellites.

DATA COMMUNICATION VS TELECOMUNICATION

Human process Human & Machine process

Machine & Machine process

DATA REPRESENTATION

PROTOCOL

DATA COMMUNICATIONS SYSTEM COMPONENTS

DATA COMMUNICATIONS SYSTEM COMPONENTS

DATA COMMUNICATIONS SYSTEM EFFECTIVENESS

NETWORKS

NETWORK CRITERIA

NETWORK CRITERIA

TYPES OF NETWORK

LOCAL AREA NETWORK (LAN)

METROPOLITAN AREA NETWORK (MAN)

WIDE AREA NETWORK (WAN)

INTERNETWORKS (The Internet)

DIGITAL AND ANALOG DATA

• Analog and digital signals are used to transmit information, usually through electric signals.

• In both these technologies, the information, such as any audio or video, is transformed into electric signals.

• In analog technology, information is translated into electric pulses of varying amplitude.

• In digital technology, translation of information is into binary format (zero or one) where each bit is representative of two distinct amplitudes.

DIGITAL AND ANALOG DATA

DIGITAL AND ANALOG DATA