DATA COMMUNICATION

Data Communication

• Data communication is the transmission of data from one location to the other.

• Data can be sent in two ways:• directly from one device to another. Eg. Bluetooth

connections• or via a server eg. Networked computers

Computer Networks

• A computer network is a set of computers that are linked together by cables or wirelessly that share information with each other.

• Computers on the network can:• Access the same files held on one server• Share resources like a printer or scanner• Share files with each other

Types of Computer Networks

• LAN – Local Area Network• MAN – Metropolitan Area Network• WAN – Wide Area Network

LAN (Local Area Network)

LAN

• A local area network is made up of 2 or more computers and or peripherals connected to each other within the same geographical area via cables or wirelessly. Not necessarily in the same building.

MAN (Metropolitan Area Network)

MAN

• A network built across a whole town or city.• It connects many LANs together and is usually run by one company.

WAN (Wide Area Network)

Remote connection

WAN

• A network that connects computers over a very wide area across different geographical locations.

• It uses satellite and other connections other than cables because of the distance.

• WANs share information across organizations so that files can be accessed from anywhere across the world.

Comparison ChartLAN MAN WAN

Location Same geographical area

Stretched across a city

Stretched across the world

Connection Cable Wireless and the internet.

Wireless, The internet and Satellite.

Businesses

Small companies Large organizations

Multi National Organizations

Advantages and DisadvantagesADVANTAGES DISADVANTAGES

All information stored on one server for easy access

Expensive to set up and may require additional employees to maintain

Many users can share files easily across large geographical barriers

Network security can be compromised by hackers

Easy management of company’s information

Easy way of communication via the internet or voice

Proper standards maintained across the company

Servers

• File Server• Stores files that will be accessed by the whole network

in one central location.

• Print Server• Connects a printer to one central location so that

everyone can print to it.

Modem• A device that converts digital signals to analogue and vice

versa. Measured in bps (bits per second)• Data sent is on wires is analog and needs to be converted

to digital so the computer can understand it.