Week 4 (part 1)

Week 4 (part 1)

In week 4 the lecturer taught us about the networks. Networking is really important in field of ICT. We did alot discussions in this week about Networking and we finally concluded without networking its really difficult  to do new inventions.
Computer network:
It is simply a group of interconnected computers. eg the internet, ATM, school network etc.
Network components:
Major components of a computer network:

• Communication media
• Interconnecting devices
• Computers
• Network software
• Applications

Data communications:
Data communication is the transmission of electronic data over some media .The media may be cable, microwave.

 Characteristic of Data Transmission :

There are three main characteristics of data transmission which ,I am going to discuss below.

• Bandwidth
• Serial or Parallel data transmission 
• Analog and Digital signal

First I am going to describe Bandwidth.

Bandwidth:
The bandwidth is related to the connection speed at which certain portion of data are transferred over the internet.

Parallel and Serial transmission of data :

Parallel data transmission:

In parallel transmission,multiple bits are sent simultaneously on different channels within the same cable,or radio path, and synchronized to a clock.

Serial data transmission:

In serial transmission, bits are sent sequentially on the same channel (wire) which reduces costs for wire but slow the speed of transmission. Also,for serial transmission, some overhead time is needed since bits must be  assembled and sent as a unit and then disassembled at the receiver.

Analog and Digital signal:
Analog signal:
Analog signal is a continuously varying representation of a condition,physical phenomenon ,or quantity such as flow, pressure, or temperature, transmitted as electrical,mechanical, or pneumatic energy.
Digital signal:
A digital refers to an electrical signal that is converted into pattern of bits.Unlike an analog signals,Which is a continuous signal that contains time- varying quantities, a digital signals has a discrete value at each sampling point