Communication

&

Telecommunication

Information/Data/Signals

2

Information Data Signal

001011101

Communication,

The exchanging of information, ideas or news is called Communication.

Communication is the activity of conveying meaning- ful information.

Technology includes non-telephone oriented systems such as radio-based communications systems for aircraft, ships, etc.

Two way process of reaching mutual understanding in which participants not only exchange of information  but also create and share information..

Telecommunication

Telecommunication is the process of transferring data electronically from one place to another. Data can be transferred using different medium.

Technology includes telephone networks(non-mobile&mobile) telex networks, etc

Communication over a distance by cable, telegraph, telephone, or broadcasting is called telecommunication.

Basic elements of data communication are:1. Sender

2. Medium

3. Receiver

SenderThe sender is the device that sends

the data. It is also called Source.

Example:Computer, mobile device etc

Basic elements of data communication…

MediumThe medium is the path that connects the sender and the receiver. It is used to transmit data. It is also called communication channel.

Example:Copper wire, Fiber-optic cable, air waves etc.

Basic elements of data communication…

ReceiverThe receiver is the device that accept the data. It is also called sink.

Example:Computer, Printer etc.

Communication Channels

The path through which data is transmitted from one place to another is called channel. It is also known as communication media. Or

A medium through which a message is transmitted to its intended audience, such as print media or broadcast (electronic) media.

Have Two types:

1.Wired Media2.Wireless Media

Communication Channels

1.Wired /Physical/Guided

In guided media, communication devices are directly connected with each other by using some physical media like wires.

Some examples of guided media. Twisted Pair Coaxial Cable Fiber Optics

Communication Channels

2.Wireless/ Unbounded/Unguided Media

In unguided media, communication devices communicate with each other through air or space.

Example. Microwave Communication Satellite Broadcast Radio Cellular Radio

Modes of Communication

Data is transferring by three ways Simplest

Half –Duplex

Full -Duplex

SimplestFeatures: a) Unidirectional

b) Send-only or Receive-only devicesc) Sender is unaware about the status of transmission.d) Rarely used for data communication.

In simplex mode the communication can take place in one direction. The receiver receives the signal from the transmitting device. In this mode the flow of information is Uni.-directional.e.g. Television, or Radio and Data from computer to Printer.

Sender Receiver

Half -DuplexFeatures:

a) Two-way communication but not simultaneously.b) At a moment it is unidirectional only.c) Can alternately send and receive data.c) Transmission direction can be changed when required.d) Delay factor (Line Turnaround Time) is associated.

In half-duplex mode the communication channel is used in both directions, but only in one direction at a time. Thus a half-duplex line can alternately send and receive data. e.g. Half-duplex system is a two-party system such as a "walkie-talkie" Sender

or Receiver

Receiver or

SenderOR

Full-duplexFEATURES:

a) Also known as Duplex Modeb) Communicates in both directions simultaneously.c) Line Turnaround time is eliminated.d) Much efficient mode.

In full duplex the communication channel is used in both directions at the same time.There is no need to switch from sending to receive mode like in half duplex.e.g. This mode of communication is the telephone line

Sender & Receiver Receiver &Sender

AND

Computer Networks

Network Network is a group of two or more computers and

devices connected via transmission media for communications purpose.

The computers can be geographically located

anywhere. Through Network we can share hardware resources, information etc.

Types of Network

PAN(Personal Area Network)  LAN (Local Area Network) MAN (Metropolitan Area Network) WAN(Wide Area Network)

Types of Network

PAN: A computer network organized around an individual person. Personal area networks typically involve a mobile computer, a cell phone and/or a handheld computing device such as a PDA. 

WPAN (wireless personal area network) is a PAN carried over

wireless network technologies such as Bluetooth,

Wireless USB etc.

The reach of a WPAN varies from a few centimeters to a

few meters.

LAN That interconnects computers in a limited area Network or a

small geographical Area (Room, Building or a Campus) is called LAN (Local Area Network)

such as a home, school, computer laboratory, or office building using network media.

Example: Computer network of a University campus

Types of Network

MAN A computer network that usually spans a city or a large

campus. A MAN usually interconnects a number of LANs using a high-capacity backbone technology, such as fiber-optical links, and provides up-link services to WAN and the Internet. or

A MAN is a large computer network that cross the campus but within the city. Its scope falls between a WAN and LAN.

It connects more then one LAN. Just like Medical College and Main campus etc.

WAN

Any network that links across metropolitan, regional, or national boundaries. Business and government entities with WANs to relay data among employees, clients, buyers, and suppliers from various geographical locations. or

A network in which computers are separated by great distances, typically across cities or even continents.

May consist of several interconnected LANs Example: The network connecting the ATM of a bank located in

various cities Internet