Telecommunication and Networking lesson 7

Hi every body :) today I want to start class with a song which is I  love! Switch of the lights and close your eyes.. feel relax... :)))


okey guys that's enough Let's look at our topic ! 


This week we continue to Wireless Technology by looking to Wi-Fi and blue-tooth. 


# Bluetooth 

-it designed for short range (10m)

-we can send the information using by:

mobile phones, laptops, PCs, printers, digital cameras. 

-Frequency 2.4 GHz 

-Data speed up to 3Mbps

How data transfer by Bluetooth ??? It is clear and easy ! Let's watch this helpful video :) 

http://www.ehow.com/video_4756777_transfer-between-bluetooth_enabled-phones-devices.html

# Wi-fi produced for mobile phone but nowadays also we can use it for more services such as ;  Internet, Voip (phone access), Tv, DVD players etc. Wife use same radio frequency as Bluetooth but the speech is more powerful than bluetooth. 

 I draw a comparison table :) i wish it will help you :) 

Wireless networking Technologies Bluetooth VS Wi-fi J

Bluetooth                                           Wi-Fi

Frequency	Low	High
Power	low	hight
Security	2.4 GHz	2.4Ghz
Cost	Low	High
Primary devices	Bluetooth adaptor onb all the devices connecting with each other. Eg.mobile phone	Devices of the network, a wireless router etc.
Range	1O merters	100 meters
Standard	IEEE – 802.15.1	IEE – 802 .11
Data rate	723 kkbits/s	11 to 105 Mbits/s

Piconet and scatternet


The basic unit of networking in Bluetooth is a piconet. A piconet is the type of connection that is formed between two or more Bluetooth-enabled devices.  scatternet is a number of interconnected piconets that supports communication between more than 8 devices. 

Broadband

The term broadband refers to any type of transmission technique that carries several data channels over a common wire. For example, combines separate voice and data channels over a single telephone line.

Thank you so much for reading my Blog :) 


terima kasih :) jumpa lagi :)

Telecommunication and Networking lesson 6

Hi everyone :) this week our topis is ; 

Unbounded media or wireless technology 

Unbounded media transports the electromagnetic waves without using a physical conductors. They use signals thought air or water to transmit signals. therefore signals available to anyone who has a device capable of receiving them. 

Radio frequency (RF)

Radio communication is devided into eight ranges called bands.  I found same information about RF it is clear and easy to understand about it. 

A sound wave is produced with a frequency of 5 Hz - 20 kHz.
The sound wave is equivalent to a pressure wave traveling through the air.
A microphone converts the sound wave into an electrical signal.
The electrical wave traveling through the microphone wire is analogous to the original sound wave.
The electrical wave is used to encode or modulate a high-frequency "carrier" radio wave. The carrier wave itself does not include any of the sound information until it has been modulated.
The carrier wave can either be amplitude modulated (AM, top) by the electrical signal, or frequency modulated (FM, bottom).
The signal is transmitted by a radio broadcast tower.
Your radio contains an antenna to detect the transmitted signal, atuner to pick out the desired frequency, a demodulator to extract the original sound wave from the transmitted signal, and an amplifier which sends the signal to the speakers. The speakers convert the electrical signal into physical vibrations (sound).

 

Cellular telephony

it designed to provide stable communication connections between two moving devices or between one mobile unit and one stationary unit. 

Wireless technology

Let's look this topic by a video :) 

Telecommunication and Networking lesson 5

:) Hi everyone I am here again let's look for our topic :) 


Cabling :) 


everyday we use cable for connect to internet with our desktop or laptop. cables carry information from one network device to another . there are four types of cable ;

• Unshielded Twiested Pair (UTP) 
• Shielded Twisted Pair (STP) 
• Coaxial Cable
• Fiber Optic Cable

UTP and STP 

UTP is comes from two forms : unshielded and shielded. 

it transmitting data and voice . inside of  each twisted cable consist 

an solid copper conductors and outside covered with a PVC. 

this two wires are twisted around each other at regular intervals. 

Advantages UTP id cheap, flexible and easy to install.

electronic industries are produce 1 unshielded to 5 unshielded 

also UTP ha maximum segment length of 100 meters.

STP is shielded twisted pair cable. it has only one 

differences from UTP ,it has metal foil covering for each pair. 

it prevents electromagnetic noise and STP uses the same connectors as UTP, but the shield must be connected to a ground. 

STP more expensive then UTP but less susceptible to noise. 

COAXIAL CABLE 

Coax carries signals of higher frequency ranges than twisted-pair cable. 

from inside to outside it has inner conductor,insulator,outer conductor, 

insulator and plastic cover. the metal shield conserve the signals from outside effects.

OPTICAL FIBER 

Optical fiber transmit signals in the form of light and it consists glass core inside 

and it is transmits light rather than others.

also it is able to transmits data for long distance than coaxial and twisted pairs.  

10BaseT : Unshielded Twisted Pair : 100 meters

10Base2 : Thin Coaxial : 185 meters

10Base5 : Thick Coaxial : 500 meterS

10BaseF : Fiber Optic : 2000 meters

I hope this video will help more to understand better :)