NETWORK

WHY?

Bad

Good

Sharing software

Sharing hardware

Networks need security measures to restrict access to users.

The set-up and maintenance costs can be expensive.

Users connected to a network have access to software on the network.

each computer on the network can have access to hardware on the network
such as laser printer

WHAT?

Collection of computers and devices ( also known as nodes) connected together via communication devices and transmission media.

download

HOW Network works ?

2) Communication devices

3) Transmission media

1) Nodes

what?

a point in a network or diagram at which lines or pathways intersect or branch

eg :

  • laptop
  • printers
  • modem

What ?

Types ( how it works ?)

any type of hardware capable of transmittting data, instructions and information between a sending device and a receiving device.

  1. Modem

Digital

  • device that sends and receives data and information to and from a digital line

Wireless

Dial-up

  • device that converts digital signals to analog signals to digital signals, so that data can travel along an analog phone line.
  • devices that uses a mobile service provider"s network to connect to the internet wirelessly from a computer or mobile device.
  1. NIC vs wireless NIC
  • wireless NICs are designed for Wi-Fi connections and often have an antenna to provide better wireless reception for the computer. Older wireless cards have PCI connections while most modern wireless NICs connect to a PCI Express slot.
  • device that enables a computer or device that does not have built-in networking capability to access a network.
  1. Hub vs switch
  • receives data from many directions and then forwards it to one or more destinations
  • a device that provides a central point for cables in a network
  1. Router
  • device that connects multiple computers or other routers together and transmits data to its correct destination on a network.
  1. Repeater
  • device that forwards wireless signals from the router to cover a larger area, such as multiple floors of a house
  1. WAP
  • a central communications device that allows computers and devices to transfer the data wirelessly amomng themselves or to transfer data wirelessly to a wired network.

What ?

  • Materials or substances capable of carrying one or more communications signals.

Physical/wired/cable ( how it works?)

  1. Twisted-pair
  • The wires are twisted together to reduce noise. Noise is an electrical distubance that can degrade communications.
  1. Coaxial
  • be cabled over
    longer distances than twisted-pair cable.
  1. Fibre-optic
  • consists of dozens or hundreds of thin strands of glass or plastic that use light to transmit signals.

Wireless ( how it works?)

  1. Infrared
  • sends siignals using infrared light waves.
  1. Broadcast radio
  • distibutes radio signals through the air over lomg distances and short distances.
  1. Cellular radio
  • is a form of broadcast radio that is used widely for mobile
    communications, specifically wireless modems and cell phones
  1. Microwaves
  • provide a high speed signal transmisson
  • it can trasmit data at rates up to 4,5000 times faster than a dial-up modem
  • it use line-of-sight transmission
  1. Communications satellite
  • receives microwave siignals from an earth-based station