Week 2 : Data Communication

Assalamualaikum

1.Introduction

Data communication is process of change / transfer information in a form of a digital data (binary) in between two or more devices using electronic delivery system.

Data communication is transmitted via medium such as wires, coaxial cables, fiber optics, radiated electromagnetic waves such as broadcast radio, infrared light, microwaves and satellites.

2.Type of signal

Data cames in variety styles text, voice, picture and video.

Analogue Signal 

Like a human voice. Formed by continuously varying voltage level that create wave than be grasped by an analogue transmitter like microphone.

Frequency is a number of completed wave's cycles. Measured in Hertz (Hz), which is cycle per second.
Amplitude is wave's height that measured in voltan (V). A strong signal will create higher amplitude.

Digital Signal

Transmission of binary electrical or light pulses that only have two possible states, 0 and 1 ( language of computers).  Presented as a square wave.

The process of changing :
1. Analogue to digital signal : modulation
2. Digital to analogue signal : demodulation
Modem is the hardware used to do changing process.

 

3. Data Transmission Mode

Parallel Transmission

Data is sent at least one byte at the time, each bit in the byte taking separate path. Means that a group of bits is transmitted simultaneously by using separate line for each bit.

 

Serial Transmission

Data sent one bit at time, one after another a long a single path. A bit slower compared to parallel transmission. For example between computer to printer.

 

 3 Serial transmission mode

1.Synchronous transmission (serentak)

2.Asynchronous transmission (data lain yang dihantar bersama) Example:keyboard

3.Isochronous transmission. Example: streaming voice, video and music.

4. Direction of data transmission 

1.Simplex- one way communication. Never allows transmitting back. Example radio station

2.Half duplex- 2 direction but never at the same time. Example walkie-talkie

3.Full duplex- moves both direction at same time. Example telephone

 

5.Data compression

Encoding information using fewer bits than original representation. Example of file compression formats such as ARC and ZIP.

 

Before the class dismiss, we've been asked to create a mind map using the application "mindomo" and send it to the elearning by using format png. 

First week : Introduction telecommunication

What do I want from this class?

I want to learn more about telecommunication and networking for my career as a teacher in the future that are technologically advanced. 

 

What might I expected from this class?

Dr Dayana full with surprises. For example, Dr Dayana ordered all the students to list input, process, output and communication and sent it to elearning UTM. So student can't sleep in the class and doing another work also student always pay attention to the class.

 

Why this class is relevant to my study?

This class is relevant to my study because world today is full advanced with technology especially communication and networking. 

 

What new thoughts have come into my head so far in this first class?

Copy paste can be detected using a specific application. You also can know about something with search at google. For example, "How to create blog" if want watch video "how to create blog youtube".

 

What will I learn from this class?

I will learn more about communication and networking. 

 

Introduction to telecommunication.

Telecommunication is refers to the transfer of data (communications) from a transmitter to a receiver across a distance.

Communication over a long distance ( tele = far off )

 

Elements of computer and communications technology.

6 elements involves 

1. People : People in the development or use of computer software and hardware systems, programmer and developer. Most important elements in communication. They built, analyse and develop the system. Professional - programmer and computer engineer. End user - clerks and teachers.

 

2.Procedure : Specification of the series of actions, acts operations which have to be executed in the same manner in order to obtain always the same result in the same circumstances.

 

3.Data/information 

Data- 'raw data' be used to get information. Binary, machine-readable representation of information. 

Information- data had been formulate to get result.

 

4.Hardware- physical objects that are part of the computer system. For example input, process, output, storage and communication.

 

5.Software- refers to instructions that control the functioning of the computer.

 

6.Communication- transmission of data ( electronic data ). Conversion of data analog-to-digital digital-to-analog.