Saturday, 14 April 2012

Hardware Requirements : Devices

Communication devices are hardware components that enable a computer to send or receive data, instructions and information to and from one or more computers.

Examples of communication devices are:
  • Network Interface Card (NIC)
  • Wireless Network Interface Card (WNIC)
  • internal and external modem
  • hub or switch
  • router
  • wireless access point
NETWORK INTERFACE CARD

A network card, sometimes pronounced as NICK, is an adapter card or PC card  that enables the computer to access the network.
A Network Interface Card is a piece of computer hardware designed to allow computers to communicate over a computer network. The card implements the electronic circuitry required to communicate using a specific physical layer and data link layer standard such as ethernet or token ring

WIRELESS NETWORK  INTERFACE CARD
 
Wireless Network Interface Card is a network card that provides wireless  data transmission.
A Wireless Network Interface Card or WNIC is a network card which connects to a radio-based computer network.
WNIC is an essential component for wireless desktop computer. This card uses an antenna to communicate through microwaves.
WNICs are designed around the IEEE 802.11 standard which sets out low-level specifications on how all wireless networks operate and can operate in two modes known as infrastructure mode and ad hoc mode.

NETWORK COMMUNICATION CHANNELS

There are two types of modem, internal modem and external modem. An internal modem only works in stand-alone computers. It is built into the computer.
An external modem is separated from the computer and is also mobile.
A modem is a device that enables a computer to transmit data over telephone or cable lines.
Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem converts between these two forms.

HUB/SWITCH 
Hub or switch is a common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN.
Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports.
When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all the packets.
A hub connects all the devices on its ports together. A switch understands when two devices want to talk to each other, and gives them a switched connection.


ROUTER

A router is a communications device that connects multiple computers or other routers together and transmits data to the correct destination.
A router is a computer networking device that forwards data packets across a network toward their destinations, through a process known as routing.
A router acts as a junction between two or more networks to transfer data packets among them. In order to route packets, a router communicates with other routers using routing protocols.

WIRELESS ACCESS POINT

A wireless access point is a device that connects wireless communication devices together to form a wireless network.
Wireless access point (or Wireless AP) usually connects to a wired network and can relay data between wireless devices and wired devices.
Several Wireless APs can link together to form a larger network that allows "roaming". Wireless access points have IP addresses for configuration.



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