BASIC CONCEPT OF NETWORK	NETWORK ARCHITECTURE	NETWORK TOPOLOGY

BASIC CONCEPT OF NETWORK

What is NETWORK?
Network is a collection of computers and mobile devices connected together via communications devices and transmission media often wirelessly computers to share resources.

 

COMMUNICATION DEVICES: Hardware component that enables a computer to send(transmits)and receive data, intsructions and from one or more computers
Hub/Switch      a communication device that enables a computer or device that does not have built-in networking capability to access a network	Modem                    A device thet enables a computer to communicate over analog networking media WIRELESS MODEM: modem that connects to the serial port but does not connect to telephone lines.It receives through the air
Wireless Access Point                          A device on a network that connects wireless devices to that network	Router                   A device that connects multiple networks together
Hub The device that provides a common central connection point for nodes on network	Switch             A device used to connect multiple devices on asingle (typically wired)network
Network Interface Card(NIC)/Network card                   An adapter /expansion card that connect a computer to a network WIRELESS NETWORK INTERFACE CARD: An expansion cards through which a computer can connect to a network that provides wireless data transmission	Repeater                          A device that enhance the weaken signal and repeat it at its original strength
Mobile phones Portable DVD players Portable media players                                                                                        -these are devices that can be carried and transported easily by a person -They are used to communicate information to both the user and other people

HUB VS SWITCH

HUB	SWITCH
Transmits signal to all other ports a computer is connected to but only the intended recipients will acce[t the resr will ignore.	Transmit signal to only intended recipients

TRANSMISSION MEDIA
The materials or subtances capable of carrying one or more signals

PHYSICAL send signals through cable ,wire or tangible materials	WIRELESS send signals through the air or space
1)Twisted-pair cable             physical transmission media which the cable consisting of pairs of copper wire that are twisted together	1)infrared send signals using infrared light waves from one device to another
2)coaxial cable                          consists of a single copper wire surrounded by at least three layers:1)an insulating material,2)a woven or braided metal,and 3)a plstic outer coating	2)Microwaves Radio waves that provide a high-speed signal transmission using electromagnetic radio wave
3)Fiber optic                       physical transmission media that consists of dozens or hundreds of thin strands of glass or platic thar use ligth to transmits signals	3)Celular radio Is a form of broadcast radio that is in wide ude for moble communication
	4)Broadcast radio Distributes radio signal through the air over long distances
	5)Communication satellite An earth -orbiting device that relays communications signals over long distances.
	6)Bluetooth A networking standard for every short - range wireless connections ;the devices are automatically connected ince they get within the allowable range.

ADVANTAGES AND DISADVANTAGES OF NETWORK

ADVANTAGES	DISADVANTAGES
1)HARDWARE SHARING-Network facilitate the sharing of hardware devices such as printer	1)UNDESIRABLE SHARING-viruses are easily spread over network and the internet
2)DATA AND INFORMATION SHARING-enable many people to access and share the same data such as database and group software development	2)SECURITY ISSUES-a compuer hacker can get unauthorized access by using different tools
3)FACILITATE COMMUNICATION-People communicate efficiently and easily via e-mail,VoIP	3)NETWORK HARDWARE,SOFTWARE AND SETUP COSTS-setting up a network requires an investment in hardware ,software of network