FCC 113 (Week 4)

Basic Networking Concept

       What I want to explain in this week is basically about Computer Network. So, what is Computer Network?

Computer Network is a group of interconnected computers that two or more computers are connected via hardware or software, and able to communicate with each other. For example of a computer network: the Internet, ATM, school network, e-banking, home network, etc. Nowadays, Computer Network has three basic networking concept, as we know three of them are:

1.     Topology (the physical layout of the network)

2.     Protocol (the rules in data communication)

3.     Architecture (how the hardware and software are integrated to form a working).

As the new knowledge for me, I would like to describe about the typical ways of networking computers.

q Communication Channel

Ø Some type of link through which the data can be transmitted or transferred from one computer to another.

Ø To send data through the channel requires some type of transmission media, which may be either physical or wireless.

q Network Medium

Ø Computers share access to common network medium that carries signals from one computer to another.

Ø Medium may be physical cable, such as twisted pair, coaxial, or fiber-optic.

Ø Medium may also be wireless.

q Physical Media

Ø Twisted-pair cable – consists of two independently insulated wires twisted around each other (least expensive type of cable—the kind that is used in many telephone systems)

Ø Coaxial cable – consists of an insulated center wire grounded by a shield of braided wire (the primary type of cabling used by the cable television industry;  it is more expensive than twisted pair)

Ø Fiber-optic cable – contains hundreds of clear fiberglass or plastic fibers (threads) (made from thin, flexible glass tubing; bandwidth is greater, so it can carry more data; it is lighter than metal wires and is less susceptible to interference; it is fragile and expensive)

Ø ISDN line – a special digital telephone line that transmits and receives information at very high speeds.

q Wireless Media (unguided medium)

 Ø Microwave system – transmits data via high-frequency radio signals through the atmosphere

Ø Satellite system – receive transmitted signals, amplify them, and then transmit the signals to the appropriate locations

Ø Cellular technology – uses antennae resembling telephone towers to pick up radio signals within a specific area (cell)

Ø Infrared technology – transmits data as infrared light waves from one device to another, providing wireless links between PCs and peripherals.

q Wireless Networking : Wi-Fi

Ø Wi-Fi is an abbreviation for Wireless Fidelity and a catch all phrase for the several different standards and recommendations that comprise wireless networking. 

Ø IEEE 802.11.b –2.4GHz – 11Mbps

Ø IEEE 802.11.a – 5GHz – 54 Mbps

Ø IEEE 802.11g – 2.4Ghz – Hybrid 11/54Mbps 

Ø Wi-Fi enables the user to deploy a computer network without needing to run cable throughout the facility.

Ø Microwave ovens, cordless phones, medical and scientific equipment, as well as Bluetooth devices, all work within the 2.4 GHz frequency band.

       Knowing and understanding types of Network is really important for users who always use the connection to connect among computers in the world. So, I will explain briefly about the types of network and its function. These types of network are called as LAN, MAN and WAN. So, what are they?

v LAN (Local Area Network) is a network in small geographical area, such as room, building or a campus.

v MAN (Metropolitan Area Network) is a network that allows users connect in a city.

v WAN (Wide Area Network) is a network spread geographically, likes country or across globe.