The 4th lecture :)

Seriously, while I'm still feeling like it's just the beginning of the semester, there goes the mid-term test and here it comes the
4th official lecture !

Ya, time and tide wait for no man.

This week, we got to explore more about network topology in the class, which I had covered through my own readings on last 2 week's blog entry :)

View me :) Scroll down :) Network topology's here :)


Furthermore, we learnt about ATM.

It's not the ATM  ( Automated Teller Machine ) which we withdraw money from okay XD

It's ATM ( Asynchronous Transfer Mode ) which is a standard switching technique designed to unify telecommunications and computer networks.

 

ATM

- uses asynchronous time-division multiplexing
- encode data into small, fixed-size cells
-provides data link layer services
- has functional similarity with both circuit switched networking and small packet switched networking.
- uses a connection-oriented in which a virtual circuit must be established between two endpoints before the actual data exchange begins.


There are 2 common types of architecture.

1. Peer-to-peer

* every workstation has equivalent capabilities and responsibilities. (workstations are peers to each other XD )
* generally simpler
* usually do not offer the same performance under heavy loads.
 
2. Client-server

* each computer or process on the network is either a client or a server.
* Servers are powerful computers or processes dedicated to managing disk drives (file servers), printers (print servers), or network traffic (network servers )
* Clients are PCs or workstations on which users run applications. 
* Clients rely on servers for resources.

Sharing is caring ^^ Click to view ^^

It's someone's coursework and he's doing a comparison of Peer-to-Peer Networks and Client/Server networks.

What is protocol ?

- special set of rules that end points in a telecommunication connection use when they communicate.
- specifies interactions between the communicating entities.
- a set of rules that governs the communications between computers on a network. In order for two computers to talk to each other, they must be speaking the same language.

There are 4 major network protocols:

1. Ethernet

 * a family of computer networking technologies for local area networks (LANs) commercially introduced in 1980.
 * uses a bus or star topology and supports data transfer rates of 10   Mbps.
 * The Ethernet specification served as the basis for the IEEE 802.3 standard, which specifies the physical and lower software layers.

2. Token Ring

* is a local area network protocol which resides at the data link layer (DLL) of the OSI model.
* second most widely-used protocol on local area networks after Ethernet.
* uses a special three-byte frame called a token that travels around the ring.


3. LocalTalk

* is a particular implementation of the physical layer of the AppleTalk networking system from Apple Computer.
* specifies a system of shielded twisted pair cabling, plugged into self-terminating transceivers, running at a rate of 230.4 kbit/s.

4. FDDI

* Fiber Distributed Data Interface
* a set of ANSI and ISO standards for data transmission on fiber optic lines in a local area network (LAN) that can extend in range up to 200 km (124 miles).
* based on the token ring protocol.
* frequently used on the backbone for a wide area network (WAN)



My little reflection of the day :


The more I sail into this subject , the more I realise my innocence.

It truly comprises a lot of facilities and resources behind the convenience of every single technology we use nowadays. 

We should have appreciated the ones who work these all out while enjoying the speed of internet and the ease of communication.

We should have learnt more and more, as there isn't anything simply coming by itself, so do knowledge and progress :)

Introduction to Networking

Again we attended the Telecommunication & Networking class with much enthusiastism after having to delay the lesson last week :)

The new topic learnt this week is " Introduction to Networking".

Dr. Dayang has provided an intriguing example to explain the term "networking" in a highly comprehensible way :D

Firstly, let's take a ride of time machine to travel back to the Stone Age. Put your safety belt on and here we go !! :D

Now you're caveman A. You normally use drums to transmit message.

One day, you want to invite your friend, the caveman B for a game of hurling rocks at each other.

 But caveman B is living too far away that he is unable to hear you banging the drum for invitation sake.

You have 3 options :

1. walk over to B's place
2. get a bigger drum
3. ask C who lives halfway in between to forward the message.

Performing NETWORKING, you'd choose the 3rd option.

Caveman C is equal to the data-sharing linkage between caveman A and B .o

In another context, NETWORKING is a collection of connected intelligent computing devices for the purpose of sharing data.

To be more precise, COMPUTER NETWORKING connects a computer with other computers or devices to bridge the communication.

The various types of network are categorized based on geographic coverage.

The most common ones are

LAN  ---> Local Area Network

• confined to relatively small area
• eg: lab, schook. building
• rarely a mile apart ( between LANs computers )
• typical configuration : 1 computer acts as a server to store all the softwares that control the network and to be shared by all the computers attached to the network.

 WAN  ---> Wide-Area Network

• Connect larger geographic areas
• eg : JB, Malaysia, the world.
• Schools in JB can communicate with places like KL
• cable and satellite uplinks 
• uses multiplexing

MAN ---> Metropolitan Area Network

• spans a city or a large campus
• interconnects a number of LANs using technologies like fibre-optical links
• provides up-links service to WAN and the internet.

PAN --->  Personal Area Network

• used for communication among computerized devices, including telephone and personal digital assistants
• intrapersonal communication 

How are networks categorized? Using 3 properties:

- Topology ( geometric arrangement of the network )
- Protocol ( common set of rules & signals )
- Architecture ( peer to peer, client/server )


Network topology indicates how a network is designed ; there are 4 main types of network structures :

Bus Network Structure

• Only 1 computer can transfer information at a time.
• Information moves through the entire length of the cable.
• There is a terminator at the end of each cable
• Terminator absorbs signals transmitted, prevents the signals from bouncing back and causing interference.
• Advantage : simple
• Disadvantage: difficult expansion, computer malfunction affects the entire network, expensive

 Star Network Structure

• Individual computer connected to a centre point of the network
• Most common type of network
• Central network connector : hub
• Cable length betwwen the hub and the computers < 100 meters.
• Advantage: easy, computer malfunction doesn't affect the network.
• Disadvantage : relies a lot on the hub to function, costly, large amounts of cable are used.

 Ring Strucure Structure

•  individual computers connected to a single length of cable arranged in a ring.
• The information travels in 1 direction only.
• Used to connect computers locate close to each other.
• No beginning or end in a ring network.
• Advantage: easy to install, low cost, easy to determine the location of faulty connection, help prevent network shutdown.
• Disadvantage: difficult expansion, expensive.

 Hybrid Network Structure

• A mixture of many different kinds of network structures.
• Centralization network layout.

Transmission Media:

* Bounded Media ( twisted pair wire, co-axial cable, fibre optic cables)
* Unbounded Media ( AM/FM radio, TV broadcasting, Satellite communication, Microwave radio, Infrare signals)

Network Electronic Device

1.  Bridges
2. Router
3. private brance exhange (PBX)
4. multiplexer
5. concentrator
6. front end processor
7. hubs
8. gateways

My little reflection of the day :

This life is also all about networking, isn't it ? XD

Befriend, Socialize, Study, Love....

and those are the stepping stones which get us nearer and make it easier to reach our destination :)

Data Communication

So soon that it's already my second official lecture XD

I have been blogging for quite some years but never ever blog in such a way of summarising class harvest week in and week out.

Guess what? I'm gradually falling in love with the making of this very personal learning trace :）

What I write is just all what I stand for and belong to in terms of knowledge.

This awesome week, we learnt about Data Communication.

It's about：

collection and distribution 

  of the  

  electronic information （What)

  from & to  

  remote facilities （Where)

  by means of

electrical transmission system.(How)

Data can appear in a variety of styles...

Be it TEXT

Be it STILL PICTURE

Be it ANIMATED GRAPHIC

Or even VIDEO

All these types of raw data must be digitized ( converted into signal that can be understood by the communication media ).

There are 2 forms of signal which can be converted into.

1. Analogue signal

* Formed by continuously varying voltage levels that create a wave

* Represented by characteristic sine wave.

*Frequency is the number of oscillations or wavelength cycles per second. It is measured in Hertz (Hz).

*Amplitude = Wave's height (V)/ decibel (dB) 

2. Digital signal 

* Transmission of binary electrical/ light pulses that only have to state 0 & 1.

* Need to be changed into analogue signal to be transmitted through PSTN line.

The process of changing...

 The hardware used in a computer to perform this process is the MoDem.

There are 2 types of data transmission mode:

1. Parallel transmission, where a group of bits is transmitted simultaneously by using a separate line for each bit.

 like a supermarket having a number of cashier counters to serve groups of customer separately at the same time 

XD

2. Serial transmission transmits all the bits one after one another on a single line.

similar to... a single long queue !

Next, we'll take a look on Data Flow

There are 3 operation styles :

1. Simplex 
- Data is transmitted in one direction.
- The role of transmitter and receiver are fixed.
- eg: radio station, Television

2. Half-duplex 
- Message can flow in two direction.
- The role of transmitter and receiver can be exchanged.
- eg: walkie-talkie
- Better than simplex

3. Full-duplex
- Consists of 2 simplex channel
- Both station can transmit and receive simultaneously
- eg: onlie chatting, phone call

Multiplexing 

* a set of techniques that enable more than one device to combine and send their signals simultaneously through a single data link.

* Networks can transfer several types of information. Each type uses a different method.

* The latest technology of the link includes high-bandwith media eg coaxial cable, optical fibre and terrestrial and satellite microwaves.

* Each of the links has an adequate carrying capacity. When two or more devices share the same link, it will be cost-effective.

My little reflection of the day:

Have learnt the importance of being pro-active without having to wait for briefing and instruction all the time, as the only one in the class who emailed her blog url to Dr.Dayang, Sara managed to get full mark for the first class entry  due to her willing to take initiative ;)


A thousand miles of journey begins with a single step. So why afraid of taking the first move? 


We always wait for the right moment with the right self at the right place to do the right thing.


But realise it or not? We're living in a world which is elapsing..there's only RIGHT NOW.

Introduction to Telecommunications

We had our first lecture of SPPM 1013 (Telecommunication & Networking) today !

It's 29 February 2012, somehow a special day right? It only comes around once every 4 years.

I'm not a Computer Science student either. The subject only comes around when I'm doing TESL :)

I use my right hand to write, learning good English ; and my left hand to click on the keyboard, learning how to teach with the aid of technologies.

Well, today's lecture has seemingly given us a head start :)

At the very beginning, Dr.Dayang provided very lively examples to explain what communication is :D 

Dating a tree and getting no response is NOT a form of communication.

 However, instructing your pet..

" Sit here doggie bro. Let's be partners. Have the world under eyelids together！" 

Your pet listens, comes to you right behind the window..(what a literary dog XD)

Bingo ! 

and it's a 2-way-communication accomplished ! :D

In short, communication is imparting, conveying, exchange of meaningful thoughts, messages,ideas, knowledge or information by signs and sounds between 2 or more parties.


Telecommunication, on the other hand means communication over a long distance.

 So is long distance love telelove? hehe.

It's quite astonished to learn that communications technology has been started since as early as year 1562...

450 years of development maketh a world without borders today :)


Move on to the ELEMENTS of computer and communications technology...

Among six, PEOPLE is the most important element as peopleware builds, analyses and develops the entire system.

Who could the people be?

1. Professional - programmer, computer engineer,etc
2. End user (those who only know how to use without special training)- Clerk,teacher, etc

PROCEDURE is a specification of the series of actions which have to be executed.

DATA refers to binary, machine-readable representation of information.

Any physical objects that are part of the computer system, we name it HARDWARE.

There are 5 categories of ICT device :

1.  Input
2.  Process
3.  Output
4.  Storage
5.  Communication

SOFTWARE, on the contrary, has no material form.
It refers to instructions that control the functioning of the computer. There are

2 types of Software : System software & Application software.

Last but not least, COMMUNICATION involves conversion of data :

analog --> digital  

digital--> analog

With that, it's my summary of the first lesson XD

My little reflection of the day:

Dr. Dayang is a brisk and bright lecturer :) What I've really been inspired by her is that she knows students very well. She knows which part of the lecture is gonna be "boring". With this understanding, it sheered the boredom off in the opposite way round. It became the portrayal of a sense of humour.

“arr...boring yer...” said Dr.Dayang :)

I'll definitely keep this attention-drawing, tactical quote of hers in my mind and harness it appropriately when it comes to teaching topics which students normally find uninteresting in near future :D