Hello again..
As I mentioned in my previous post, I have to mention about the things that I learn in this second semester for science computer. So lets get started.
Last week I learned about NETWORK. What is network is mainly about? Well , Network is a collection of computers and devices connected together via communications devices and transmission media.
THE APPLICATION OF NETWORK
Resource sharing ( hardware and software)
Information sharing ( easy accessibility from anywhere, search capability)
Communication (email, message broadcast)
Communication Device
A
communications device is any type of hardware capable of transmitting data,
instructions, and information between a sending device and a receiving device.
There are various type of communication device
A communications
device that can convert
digital signals to analog signals and analog signals to digital signals, so that data can travel along an analog telephone line.
A communications
device that sends and receives data and
information to and from a digital line.
Some mobile users have a wireless modem that uses the cell
phone network to connect to the
Internet wirelessly from a notebook computer, a smart phone, or other mobile
device.
Sometimes called a network interface card, is a communications device that enables a computer or device
that does not have built-in networking capability to access a network.
A central
communications device that allows computers and devices to transfer data
wirelessly among themselves or to transfer
data wirelessly to a wired network .
*Wireless access points have high-quality antennas for
optimal signals.
A communications
device that connects multiple computers or other routers together and transmits
data to its correct destination on a network.
A connection device similar to a hub but more sophisticated, including functionality that allows it to control and manage data transmissions.
A connection device that
allows multiple connections to the network
 |
Figure shows the connection between devices ( router, modem and computer in a network)
Transmission media
There are two types of transmission media, which is
|
1.Physical
transmission
media/Guided media/Wired
•Twisted-Pair
CableCoaxial Cable, Fiber-Optic Cable.
2.Wireless
transmission media/Unguided
media/ Wireless
Infrared
Infrared (IR) is a wireless transmission medium that sends
signals using infrared light waves.
Broadcast Radio ( Bluetooth, Ultra Wideband (UWB),Wi-Fi, WiMAX)
A wireless transmission medium that distributes radio
signals through the air over long distances
such as between cities, regions,
and countries and short distances such as within an office or home.
Cellular Radio( 2G, 3G, 4G, 5G)
A form of
broadcast radio that is used widely for mobile communications, specifically
wireless modems and cell phones
Microwave
Microwaves are radio waves that
provide a high-speed signal transmission.
* Microwave transmission, often called fixed wireless, involves sending signals from one microwave station to another.
Communications satellite
Is a space station that receives microwave signals from an
earth-based station, amplifies (strengthens) the signals, and broadcasts the
signals back over a wide area to any number of earth-based stations.
SHARING HARDWARE
It can reduce the cost of purchasing hardware
SHARING SOFTWARE
It can reduce the cost of buying software
SECURITY
A network can be password protected and can only be accessed by authorized users.
SPEED
Sharing and transferring files within network is very rapid
Breakdown and possible loss of resources
Breakdown of the
whole network due to an issue of the server may lead to loss of important data of the server.
Expensive
to Build
Building a
network for large scale organizations
are very pricey especially to buy
and replace cables and other hardware
Security Threats
There are hackers who are trying to steal
valuable data of
large companies for their own benefit.
Bandwidth issue
Heavy users who
consume a lot more bandwidth will affect other users.
I hope that this information will gain your knowledge in computer