COMPUTER NETWORK

Assalamualaikum,

This week I have been learn about computer network. It is simply a group of interconnected computers. Two or more computers are connected via hardware or software, and able to communicate with each other. Example of a computer network, the Internet, ATM, school network, e-banking, home network, etc. 

Network computer

Major components of a computer network:

–      Communication Media

–      Interconnecting Devices

–      Computers

–      Networking Software

–      Applications

Data transmission characteristics

Bandwidth (rate of transmission)

The rate at which the data can be transmitted is measured in Bits/sec.Bandwidth is the range that a medium can correctly transmit data. The rate at which the signal changes is known as Baud rate

Analog or Digital (type of signal)

Analog transmission is takes the form of continuous waves transmitted over a medium at a certain frequency rage.Digital transmission is sends data in the form of bits

Serial or Parallel (order of bits)

Serial transmission is all of the data bits are transmitted one bit after another in a continuous line and Parallel transmission is data bits are sent at the same time along multiple paths.

Communication Channel

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

Network Medium

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

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

• Medium may also be wireless. 

PHYSICAL MEDIA

•       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)

•       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)

•       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)

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

WIRELESS MEDIA

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

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

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

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

TYPES OF NETWORK

•       Network in small geographical Area (Room, Building or a Campus) is called LAN (Local Area Network)

•       Network in a City is call MAN (Metropolitan Area Network)

•       Network spread geographically (Country or across Globe) is called WAN (Wide Area Network)

Peer-to-Peer Networking Advantages

•       Easy to install and configure

•       No dedicated server

•       Users control own shared resources

•       Inexpensive to purchase and operate

•       No additional equipment or software

•       No dedicated administrators

•      Works best with 10 or fewer users

Peer-to-Peer Networking Disadvantages

•       Security applies to single resource at a time

•       Users may have many different passwords

•       Must back up each machine individually

•       Machine sharing resources may suffers reduced performance

•       No centralized organization scheme to locate or control access to data

•       Does not usually work well with more than
10 users

I  HOPE U WILL GET SOME INFORMATION FROM MY EXPLAINATION