Sunday, 13 May 2012

week 7 :)

wireless enable people to connect networking using wireless connection across long distances. there are also infrared and radio frequency, but they are limited to area that is short-ranged. wireless are often defined as electronic waves, radio waves, and infrared.

in data networking, the type of wireless network are plenty. here are the list of them:

1) Infrared

infrared will always be associated with Infrared light. remember when we used to put our phones and friend's phones together in order to transfer pictures? that is the concept of Infrared. Infrared can only be used in a short-distance range and the transfer speed is 2400 Mbps to 4 Mbps. 

2) Bluetooth

bluetooth is also designed for a very short range which is less than 10 metres. it is used to connect and change information between devices such as computers and cellular phones. the data speed is around 3 Mbps. it also has a frequency of 2.4 GHz.

3) Broadband

Broadband is a type of wireless network that is very widely used nowadays as the speed of transmission is fast. it can be connected within 50 km of range from the transmitter. it is planned to used for many years as it is very popular among user and is considered reliable. 

Week 6 - Unbounded Media/Wireless Transmission Media

What is Wireless?

Wireless is a type of network but without cable. there are several devices that we can use to transport information via wireless and this devices are called unbounded media or transmission media. It is a very useful media as it enables user to conveniently connect to the Internet anytime they want to as long as there are connection. therefore, we will move on to the type of media that it unbounded. 

1) Satellite

satellite is one form of wireless device. in satellite, there are receiver and transmitter. satellite is also known as the strongest type of wireless media as it transmit information faster than any other wireless media. 
UPLINK : transmisson from Earth so satellite
DOWNLINK : transmission from satellite to Earth

2) Cellular phones

Another type of wireless media is cellular telephone which is commonly used in our society nowadays. it actually works by transmitting radio waves that can be used in longer distances. normally, if we want to connect to the Internet using Wireless connection, we have to be closer to the transmitter in order to get better connection. 

3) Antenna

There are two types of antenna. they are :
a) Parabolic dish
- it is normally placed on high places in order to transmit waves better.

b) Horn antenna
- it is used to receive and transmit waves. 
- the horn is designed specifically for minimise any disruption of unwanted signals. 

4) Broadcast radio
- can be used in farther distance
- transmission of waves require transmitter and receiver
- negative points : Slower

1G, 2G, 3G, 4G