Comput3r N3tworks

Hi, everyone! Time passes so fast that here comes the fourth lesson of us with our lecturer, Dr.Dayang. Today we learn about 'Computer Networks'. After the lesson today, I gain some extra knowledge on networking, for example types of LAN used, definition of server, the differences of the four transmission media (Router, Gateways, Bridges and Hub). Besides, my coursemates have put pretty much effort on presenting the application of E-mail to us which is very informative and systematic. I really learn a lot and this is the first time I am exposed to the software named 'Thurderbird' that is very useful fo rme to check my e-mail even I am offline.

Below are the summarize of mine for today's lesson:

What is networking?

• Networking is a collection of computer and other hardware devices that are connected together to share hardware, software and data as well as to communicate of one another.

What is server?

• Server is to store all software that controls the network and to share by all the computers attached to the network. 

How many types of network classification?

• Network used based on geographic coverage.
• Basically have four types of Network: LAN (Local Area Network), WAN(Wide Area Network), MAN( Metropolitan Network) and PAN(Personal Area Network).

LAN

• restricted to relatively small area. e.g. lab, school or building
• rarely more than a mile apart.
• typical LAN configuration: 1 computer = a server
• cable are used to connect the network (cable can be bound and unbound)

WAN

• connect larger area such as JB Malaysia, World Cable or satellite uplinks used to connect this type.
• is complicated.
• using multiplexing to connect local and metropolitan network : hybrid network.

MAN

• usually spans a big/large campus.

PAN

• computer network organized around an individual person.

How are networks categorized?
 based on 3 properties: -

• Topology      : geometric arrangement of the network
• Protocol       : common set of rules and signals the communication on the network use to          communicate
• Architecture : peer to peer / client / server

How many types of transmission media?
2 types:-

• bounded media (with cable) and unounded media (wireless)
• bounded media e.g. twisted pair wire, co-axial cable, fiber optic cables
• unbounded media e.g. AM and FM radio, TV broadcasting, satellite communication, microwave radio, infrared signals.
•  e.g. Router, Gateways, Bridges and Hub.

Router

• Devices which connect two or more networks that use similar protocol.
• Operates at a network layer of O.S.I model
• Data is grouped into packets / block of data. Network address allows routers to calculate more accurately and efficiently the path of the computer.

Router

Gateways
• Devices which connect two or more networks that are different protocols.
• Operate at all seven layer of O.S.I model.
• Perform data conversion that is why slower in speed and expensive devices.

Gateways

Bridges

• Used to connect similar network segments
• Bridges work at the data link layer of O.S.I model.
• Bridge possesses infomation about the data they receive with slow performance.

Bridge

 Hub ( 4 types of Hubs : Passive Hub, Active Hub and Switch/Intelligent Hub)

• Are basically multiports repeaters for U.T.P. cables.
• Hubs have ports for other type of cable such as coaxial cable.
• Range on size for 4 ports and specific to the network type.

Hub

That's all from me.. Thank you for reading:)

Introduction to Data Communication

Hi, everyone!!! I'm back. Time passes so fast that we are already in week 3. Today is our third lesson for  telecommunication and networking class. The topic we learn today is 'Data Communication'. In today's lesson, I do obtain some input and gain extra knowledge on data communication. It's great to learn new things.

Okay, let's straight to the point!

What is the definition of Data Communication?

• Basically, Data Communication is simply means the collection and distribution  of the electronic representation of information FROM and TO remote facilities by electrical transmission system such as telephone lines, satellites or coaxial cable. *coaxial cable = a cable which has an inner conductor surrounded by flexible, tubular insulating layer with tubular conducting shield. It is used as the transmission line for radio frequency signals.

As illustrate on the diagram above, internet is collected in head office and distributed to regional office and remote/roaming users.

• Information appear in variety of format MUST BE DIGITIZED so that the information can be understood by the computer and convey the RIGHT message to the viewers.  

There are how many types of signal?

• 2 types :-   i) Analogue Signal  ii) Digital Signal

Analogue Signal
-  formed by continously varying voltage level that create a wave that can be grasped by an analogue transmitter like microphone.
- has features: frequency and amplitude

- Analogue signal is transmitted through PSTN (phone line).

Digital Signal

- Transmission of binary electrical ONLY in the the states of 0 and 1. e.g. bit, bytes, kilobytes, megabytes, gigabytes and terrabyte.

- Digital signal =) analogue signal to be transmitted through PSTN line.

How is the word 'MODEM' originated??? (MOdulator or DEModulator)

It is the process that converts data into electrical signals (analogue =) digital signal = MOdulation) that can be transmitted over the telephone and vice versa. (digital =) analog signal = )

DEModulation)

The continous conversion of signals

There are how many Data Transmission Mode???

• 2 types : - i) Parallel Transmission 

                          ii) Serial Transmission ~ Synchronous Transmission  

                                                                ~ Assynchronous Transmission

Parallel Transmission

A group of bits is transmitted simultaneously using a separate line for each bit.

Serial Transmission

Transmit all the bits one after another on a single line. This transmission is slower as compared to parallel trasmission.

i) Synchronous Tranmission - A large group of data is transmitted in blocks called FRAME.

ii) Assynchronous Transmission - Bits divided into small groups (bytes) and send independently.

                                                     - a group of bits send anytime and receiver unaware they arrive.

How many ways the data can flow?

Communication between 2 pieces of equipment in exchanging process can be done in three ways:

- simplex ( data is transmitted ONE direction only) e.g. radio station/TV

- half-duplex ( 2 direction BUT NEVER at the same time) e.g. Walkie-talkie

- full-duplex ( both station can transmit and receive simultaneously) e.g. phone call

Apart from that, MULTIPLEXING is a set of techniques that enable more than ONE DEVICE to combine and send their signals simulaneously through a single data link at the SAME TIME.

That's All From Me Today..Thank You for Reading!!!



Telecommunication and Networking

Wow!!! It is a brand new semester, new beginning and new hope for me. Everything gonna be change. Frankly, I see the difference in me when compared the PAST and PRESENT. Somehow it is a good sign. I realise myself growing up rapidly within these couple of months in the sense of I becoming more independent, stronger and tougher. I learn how to face difficulties and challenges in my life with a smiling face.@.@ It is also definitely a chance for me to learn how to appreciate my FAMILY. They are pretty essential to me as they are my supporters wherever I go and we share happiness and sorrow together.

      I really can't imagine myself I will write a blog as it is not my style. However,  I am glad that I have the opportunity to try something new.yaa.. thank you, Dr. Dayang! All of you might wonder who is Dr. Dayang. Well, before I introduce Dr. Dayang, please give her a big round applause first..xD She is our Telecommunication and Networking (SPPM 1013) lecturer. The first impression I get from Dr. Dayang is she is very friendly, cute, has a sense of humour and dedicated. She tries to remember all her students' name as she cares for us. She is also being an understandable person whereby she puts herself in her students' shoes. That's great!

Okay, back to the topic. What have I learnt for today's lesson? Today is the second lesson for telecommunication and networking class whereby Dr. Dayang starts the class by briefing us the individual and group assignment.(yup..it's a bit tense up). Next, Dr. Dayang gives us lecture on 'Introduction to Telecommunication and Networking'. For me, telecommunication and networking becomes more and more popular especially in this world of globalisation. Even a gorilla dwelling in a jungle know how to use ipad 2. It is pretty amazing!

Below are the summarize of mine for today's lesson:

• What is the meaning of 'communication'?

- Communication is the process of imparting, conveying /exchange of thoughts, messages, ideas, knowledge /information by sign and sounds like speech, signals, writing/behaviour.
- Communication can be said as complete once the receiver can get the meaning from the sender.
- Communication is effective when there is an interaction between the two communicating parties.

• What is the meaning of of 'telecommunication'? (tele = far off)

- Telecommunication is a form of communication over a long distance whereby transfer of data (communication) from a transmitter to a receiver across a distance is occured.
- The data/code for telecommunication is represented by some form of electromagnetic energy: electricity, radio, waves and lights which are transmitted through medium: wire, cable and atmosphere.

•  The 6 elements of computer and communications technology:-

1) People       2)Procedure   3)Data/Information
4)Hardware   5)Software     6)Communication/Connectivity 

However, the most important element is the PEOPLE. Without people, there is no point for us to communicate.

1) People
- user of the computer
- built, analyse and develop the system
- 2 categories of people:
  i) Professional: Those who have gone through specialised training in theory and technical                aspects.e.g.programmer, computer engineer and etc.
 ii) end user: Those who know how to use without training. e.g.clerks, teachers and etc.

2)Procedure
- an orderd set of tasks for performing some action.
- a clear specification for the sequence, training, execution of a process.

3)Data
- information stored on the computer system, used by application to accomplish task.

4)Hardware (equipment/devices)
- physical object that are part of computer syatem.
- basic operation of computer system.
- 5 categories of ICT equipment: IPOSC

I = Input   P = Processor  O = Output  S = Storage C = Communication

5) Software/Program
- 2 categories: i) system software (e.g. Window, doc and etc.)
                       ii) application software (e.g. antivirus, Microsoft Office and etc.)
- instructions that control the functioning of the computer.

6) Communication/Connectivity
- is the transmission of data (electonic data)
- is the conversion of data analog-to-digital and digital-to-analog.

That's all from me. Thank you!!!Looking forward to the next class.


To be continued...stay tuned yaar...