CONNECTING A NETWORK  : WIRED & WIRELESS (PART 2)

Wired Networking

1. Twisted pair cable - a networking cable consisting of wire stands twisted in sets of two and bound into a cable. Can be used with both analog and digital data transmission and commonly used for LAN. The pair of wire are twisted together to reduce interference and improve performance.
2. Coaxial cable - a networking cable consisting of a centre wire inside a grounded, cylindrical shield, capable of sending data at high speeds. Commonly used today in computer networks, for short-run telephone transmissions outside of the home and for cable television delivery. It is much less susceptible to interference and can carry more date more quickly.
3. Fibre-optical cable - a networking cable that utilizes hundreds of thin transparent fibres over which lasers transmit data as light. Transfer data represented by light pulses at speed of billion of bits per second. Commonly used for to the high-speed backbone lines of a network.

Wireless Networking

1. Infra Red (IR) - a wireless networking medium that sends data as infrared light rays. Sends data as infrared light rays over relatively short distances. Used to beam data between some mobile devices, television remote control, etc.
2. Blue tooth - a networking standard for very short-range wireless connections, the devices are automatically connected once they get within the allowable range. Blue tooth through clothing and other nonmetallic objects.
3. WiMAX - a networking standard that is faster and has a greater range than WiFi.
4. WiFi - a widely used networking standard for medium-range wireless networks

CONNECTING A NETWORK  : HARDWARE (PART 1)

Network Hardware

• various types of hardware are to create a computer network, to connect multiple networks together, to connect a computer or network to the Internet.
• there are 7 types of hardware.

1. Network Interface Card (NIC) - an expansion card through which a computer can connect to a network. Provides the physical connection between the network & computer workstation. Major factor in determining the speed & performance of a network.
2. Repeater - are devices that amplify signals along a network. Are available for both wired & wireless networks, repeaters for a wired & wireless network are often called range extenders. Are extend the length of transmission media.
3. Switch - a device used to connect multiple devices on a single (typically wired) network, forwards packets to only the intended recipient. Contains ports to which the devices on the network connect (typically via networking cables) & facilitates communications between devices. Identifies which devices connected to the switch is the one the data is intended for & send the data only to that device, rather than sending data out to all connected devices.
4. Bridges - allows the computer on the individual network/separate parts of a network to exchange information. Advice used to bridge / connect two LANs. Most common often used to connect wired devices wireless to a network. Can only transfer information from one network to another. Also used to split on overloaded network into smaller parts.
5. Routers - connect multiple devices to a cellular network. can direct/route information to the correct destination. Automatically detect if a part of the network is not working/slow. Contain fast processors to help prevent network slowdown. Prevent looping problems by analysis the information the transfer 7 directing it to the proper destination. Are often used to connect LAN to a WAN. Can also be used to break up the WAN into segment.
6. Hubs / Concentrator - a type of multiplex that combines multiple messages & sends them via a single transmission medium in such a way that all the individual messages are simultaneously active, instead of being sent as a single combined message. The main function is to connect the wires in the network. Help to eliminate errors on the network that are caused by electrical interference.
7. Workstation - a special computer designed for technical applications. Intended primarily to be used by one person at a time. Are commonly connected to a LAN & run multi-user operating system.
8. File server - a computer attached to a network that has the primary purpose of providing a location for shared disk access, shared storage of computer files such as documents, photographs, movie, etc, that can be access by the workstation are attached to the same computer network.

here are some videos that you can watch :)

https://www.youtube.com/watch?v=U1-2gGD9sYk

https://www.youtube.com/watch?v=IRBaMcAYA-s
https://www.youtube.com/watch?v=BAQidNNnZhU

hope you will enjoy it :)

COMPUTER NETWORKING AND TOPOLOGY

Computer Networking

• a connection between two computers by direct cabling is qualified to be a network.
• in the world of computer, networking is the practise of linking two/more computing device together for the purpose of sharing data.
• networking are built with a mix of computer hardware & computer software.

Networking Classification.

1. LAN (Local Area Network) - a computer that interconnects computers within a limited area & has its network equipment & interconnects locally manage. e.g: a residence, school, laboratory, university campus, office building.
2. MAN (Metropolitan Area Network) - a computer network that interconnects user with computer resources in a geographic area/region larger than that covered by even a large LAN but smaller than area covered by WAN. e.g: the cable television network available in many cities.
3. WAN (Wide Area Network) - a computer that extends over a large geographical distance. The Internet may be considered a WAN. e.g: use technology like ATM for connectivity over the long distance.
4. PAN (Personal Area Network) - a computer network used for data transmission amongst devices. PAN can be used for communication amongst the personal devices themselves. e.g: computers, telephones, tablets, printer, fax machine, scanner, PD A's.

Network Components

1. Terminal & Workstation - normally refers to data sources & destination. e.g : personal computer, terminals, workstation.
2. Network electronic devices (network hardware) - network hardware includes all computers, peripherals, interface cards & other equipment needed to perform data-processing & communications within the network. e.g : hub, bridge, router, switch gateway.
3. Network Software - the information, data/programming used to make it possible for computers to communicate/connect to one another. e.g : Windows 95, Win 98, NOS (Networking Operating System)
4. Network Architecture Standard - Blueprint of standards for a network consisting of items such as media interface, encoding methods, transmission protocols, routing protocols.
5. Transmission media - the physical pathway that connect computers & devices on a network. have two categories which are bounded & unbounded.

• Bounded - which provide a conduct from one to another. e.g : twisted-pair cable, coaxial cable & fibre-optic cable.
• Unbounded - media transport electromagnetic waves without using physical conductor. e.g : satellite communication, cellular telephony & microwave transmission.

The Use Computer Network

• sharing physical resources such as printers.
• provide a powerful communication medium among employees.
• using computer network, manufactures can place order electronically as needed. this reduces the needed for large inventories & enhances efficiency.
• home user can access information, communicate with other people & buy products & services with e-commerce.
• can be surfing the World Wide Web for information/just for fun.
• sharing public domain music, families sharing photos, movies & user downloading public software package.
• can be used by applications to carry audio & video.

Advantages Computer Network

1. Speed - networks provide very rapid method for sharing & transferring files. This method of transferring files (referred to as sneaker-net) is very time-consuming.
2. Cost - network able versions of many popular software programmes are available at considerable savings when compared to buying individually licensed.
3. Security - files & programmes on a network can be designated as "copy inhibit", so that you do not have to worry about illegal copying of programmes.

Network Topology

- indicates how a network is design or lay out.

- network topology has 2 part which are physical topology & logical topology.

• Logical Topology : the mapping of the 'flow of'' data between the nodes in the network.
• Physical Topology : indicates how the devices in the network are arranged.

- there are 4 most common physical topology.

1. Bus network - consists of a continuous length of cable that connects 2 / more devices together. A bus called a backbone network. Each end of the cable on the bus network must have a terminator.
2. Star network - consists of individual computer connected to a centre point on the network. Each computer connected to a centre network connector, called a hub.
3. Ring network - consists of individual computer connected to a single length of cable arranged in a ring. The information travels in one direction only. There is no beginning / end in a ring network.
4. Hybrid network - a network structure used a mixture of many different of network structure. Hybrid network structure such as ring, star, bus network in one large network.

 

there are some video that you can watch :)
https://www.youtube.com/watch?v=Ap0UrGYsxrk
https://www.youtube.com/watch?v=osWctsnbMa4

HAVE FUN !!!   😉 😊

DATA COMMUNICATIONS

• Is the very simply, the collection & distribution of the electronic representation of information from & to remote facilities another by means of electrical transmission system likes telephone lines, satellites or coaxial cables.
• The information can appear in a variety of formats, data, text, voice, pictures,, graphics & video.
• Prior transmission, the raw information must be digitised.
• There are 2 type of signal which are analogue signal & digital signal.

1. Analogue signal - those used by conventional telephone systems, represent data with continuous waves.

    2. Digital signal - Which data is represented by only two discrete states 0s & 1s.

   *Analogue data that is to be sent using digital signal (such as analogue music broadcast by a digital radio station)
   *Digital data to be sent using analogue signal (such as computer data sent over a converted into analogue form before it can be transmitted)

FIGURE 1 : Picture of digital & analogue signal.

there are some video that you can watch :)

https://www.youtube.com/watch?v=EnfjYwe2A0w&t=29s

https://www.youtube.com/watch?v=Y2OPnrgb0pY

https://www.youtube.com/watch?v=C3rVRH7qCxc

Data Transmission

Data transmission has 2 types :

• Parallel transmission - The message is sent at least one byte at a time, with each bit in the byte taking a separate path.
• Serial transmission - Data is sent one bit at a time, one after the other along single path.      

There are 3 serial transmission modes which are Synchronous transmission, Asynchronous transmission & Isochronous transmission.

1. Synchronous transmission - data is organized into group / blocks of data, which are transferred at regular, specified intervals.
2. Asynchronous transmission - data is sent when it is ready to be sent, without being Synchronous transmission. To identify the bits that belong in each byte, a start bit & stop bit are used at the beginning & end of the byte.
3. Isochronous transmission - data is sent at the same time as other related data to support certain types of real-time applications that require the different types of data to be delivered at a proper speed for that applications.

FIGURE 2 : Picture of parallel & serial transmission.

FIGURE 3 : Picture of synchronous, asynchronous & isochronous transmission.

There is the video that you can watch :)
https://www.youtube.com/watch?v=PJ_bS7meE7s

Data Flow / Data Move

1. Simplex transmission - data travels in a single direction only (like doorbell). Relatively uncommon in data transmission because most devices that are mainly on-directional, e.g, printer.
2. Half-Duplex transmission - data can travel in either direction, but only in one direction at a time, e.g, walkie-talkie.
3. Full-Duplex transmission - data can move in both directions at the same time, e.g, telephone.

FIGURE 4 : Picture of simplex, half-duplex & full-duplex.

There is the video that you can watch.

https://www.youtube.com/watch?v=ju55-ffiv_M

HOPE YOU WILL ENJOY WITH THIS NOTE :)

INTRODUCTION TO TELECOMMUNICATIONS

Communication

• is the mechanism through which human relations exists and develop.
• is the simply the imparting (memberi), conveying (menyampaikan) or exchange of thoughts, message, ideals, knowledge or information by sign or sound like speech, signal, writing or behaviour.
• simply the sharing of an orientation toward a set of informational sign.
• Communication process involves 6 basics elements which are :

1. Sender / source (encoder)
2. Message
3. Channel
4. Receiver (decoder)
5. Noise
6. Feedback

Communication model

Telecommunications - is over long distance, cover all forms of distance & conversion of the original communications, including radio, telegraphy, television, telephony, data communication & computer networking.

Development of Communications Technology & Computer Technology

Here the link that you can watch about the development of communication technology & computer technology. Hope you enjoy :)

 https://www.youtube.com/watch?v=be3KZDFvDeA
https://www.youtube.com/watch?v=v94EH_cE7GY

6 Elements of Communication Technology & Computer Technology

1. People
• professional - who write the programs that computer use. e.g, programmer, computer engineer, etc.

• end user - including electronically preparing a client's taxes, an office worker using a word processing program to create a letter, a parent e-mailing his/her child's teacher, a person shopping on line, etc.  

      2. Procedure - is a clear specification for the sequence, timing, execution or a process.

      3. Data / information

• data - raw, unorganised facts.
• information - data that had been processed into a meaningful form.
• e.g, bit, byte, kilobyte (KB), megabyte (MB), etc.

     4. Hardware - physical parts of a computer.

                         - hardware component can be internal (located inside the main box/system unit of

                          computer) or external (located outside the system unit & connected to the system

                           unit via a wired / wireless connection)

                         - there are 5 categories computer operations which are input device,processing

                           devices, output devices, storage devices & communications devices.

      5. Software - the programs or instructions used to tell the computers use what to do.

                           - 2 types of software :

• system software - the program that allow a computer to operate a collectivity referred to.
• application software - consists of programs designed to allow people to perform specific tasks using a computer. e.g: playing games, watching videos, listening to musics, exchanging e-mail, etc.

      6. Communication / connectivity - the transmission of data from one device to another.
                                                            - such as, sending/retrieving data via the Internet,accessing
                                                               information located in a shared company database or
                                                               exchanging data/e-mail message with others.

THAT'S ALL .. HOPE YOU WILL ENJOY IT  :)