Data Communication

WHAT IS DATA COMMUNICATION?

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• DATA COMMUNICATION is exchange of information between two devices through some medium (wired or wireless). This includes transfer of data, method of transfer and preservation of data during transfer process.

ELEMENTS OF COMMUNICATION SYSTEM

Humanmessage

message for another

person

TransmitterCommunication

channel or medium

Receiver

Noise

Transmitter: Designed to convert the information to electrical signal.

Communication Channel or Medium: Medium by means of which the electronic signal is sent.

Receiver: The receiver accept the signal from the communication channel, decodes it, and produces the

original information.THE PORTS OF DATA COMMUNICATION:

1) Message: The information which is to be sent to the receiver.

2) Sender: It refers to device that sends the message.3) Receiver: It refers to the device that receives the

message

PROTOCOL

A set of Rules.To be followed by both the sender and the receiver.

SENDERRECEIVER

FOR EXAMPLE

DATA TRANSMISSION

modeTHREE MODES OF DATA TRANSMISSION:

SIMPLEX

HALF DUPLEX

FULL DUPLEX

SIMPLEX

•Signal travels in one direction only.•eg. television

HALF DUPLEX• Receving and transmitting data cannot be done at the same time.• Eg. Walkie talkie

FULL DUPLEX

• Allows to transmit and receive data at the same time.• Eg. Telephone

BANDWIDTH•Maximum amount of information that can be transferred over any communication medium.

THREE CATEGORIES OF BANDWIDTH

• Capacity upto 64kbps

Narrow band

• Capacity Above 1.5mbps and less than 45mbps

Wideband

• Capacity Equal to 45 mbps

Broad band

MODEMS

Modems helps to transmit data from one computer to other through telephone lines.

The Modem transmits data from senders computer to receivers computer by converting digital signal into analog signal and vice- versa.

FAX MODEM

CABLE MODEM

TYPES OF MODEMS

FAX MODEM

FAX modem is used to transmit data, pictures and another files through telephone lines from one computer to other or from one computer to a fax machine.

Cable modem

CABLE MODEM is a technology that enables home computer users to connect to internet through cable TV connections with high speed than regular connection.

DSL TECHNOLOGY• It is a modem technology access over

ordinary copper telephone line from homes and business

DSL SERVICE• It is a high speed

internet• Several types such as • ADSL,HDSL,SDSL,VDSL,e

tc

Wireless Networks

• Introduction• Types• Advantages and disadvantages

Introduction

Wireless network refers to any type of computer network that utilizes some form of wireless network connection.

Types• Wireless PAN• Wireless LAN• Wireless MAN• Wireless WAN• Wireless SAN

Advantages And Disadvantages

Advantages• Flexibility

(wirelessness)• Ease of use• Planning• Place devices• Durability• Prices

Disadvantages• Ethernet.• Compatibility issues

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