Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


Untitled Prezi

No description

fatoma alshamrani

on 12 May 2013

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Untitled Prezi

King Khalid University
Computer Science Faculty
Computer sciences Department
Seminar (CS 481)
Level: 8
 Wi-Fi and Li-Fi technology Drawbacks Of Before Technologies Wi-Fi and Li-Fi Technology * Wi-Fi is the wireless way to handle networking

* Wireless Technology is an alternative to Wired Technology, which is commonly used, for connecting devices in wireless mode.

* Wi-Fi (Wireless Fidelity) is a generic term that refers to the IEEE 802.11 communications standard for Wireless Local Area Networks (WLANs).

* Wi-Fi Network connect computers to each other, to the internet .

* Wi-Fi is a wireless technology that uses radio frequency to transmit data through the air..

* The term Wi-Fi, first used commercially in August 1999 History of Li-Fi Contents Developed by : 
Fatima Al-Shamrani 430835787
Sarah Al-Asmari 430835571
Hend Al-Ghamdi 430835801
Maram Al-Shahrani 430834598 Supervised by :
Dr. Nermeen Talaat * History
* Drawbacks Of Before Technologies
* Different Between The Technologies
* Working process
* Applications
* Advantages
* Conclusion History of Wi-Fi WIRELESS NETWORK MADE UP OF :
a. An ad-hoc, or peer-to-peer wireless network

b. A wireless network can also use an access point, or base station

Multiple access points
Increasing the number of Wi-Fi access points provides network redundancy, support for fast roaming and increased overall network-capacity by using more channels or by defining smaller cells. Harald Haas has come up with a solution he calls “data through illumination” –taking the fibber out of fibber optic by sending data through an LED light bulb that varies in intensity faster than the human eye can follow. It’s the same idea band behind infrared remote controls but far more powerful. Haas says his invention, which he calls D-LIGHT, can produce data rates faster than 10 megabits per second, which is speedier than your average broadband connection.
Li-Fi means “Light Fidelity”.
At the heart of this technology is a new generation of high brightness light-emitting diodes
It is possible to encode data in the light by varying the rate at which the LEDs flicker on and off to give different strings of 1s and 0s. HOW A Wi-Fi NETWORK WORKS? Wi-Fi Li-Fi _ A Wi-Fi hotspot is created by installing an access point to an internet connection.
_ An access point acts as a base station.
_ When Wi-Fi enabled device encounters a hotspot the device can then connect to that network wirelessly.
_ Many access points can be connected to each other via Ethernet cables to create a single large network.
_ An AP broadcasts its SSID (Service Set Identifier, Network name) via packets that are called beacons, which are broadcasted every 100ms. The beacons are transmitted at 1Mbps, and are relatively short and therefore are not of influence on performance..
_ Based on the settings (i.e. the SSID), the client may decide whether to connect to an AP.
Li-Fi is typically implemented using white LED light bulbs at the downlink transmitter.
The LED bulb will hold a micro-chip that will do the job of processing the data
The operational procedure is very simple-, if the LED is on, you transmit a digital 1, if it’s off you transmit a 0. The LEDs can be switched on and off very quickly, which gives nice opportunities for transmitting data. .
with this technology we transmits 1000's of data stream in parallel at high speeds. Working process of Li-Fi Wi-Fi Li-Fi Home
Small Businesses
Large Corporations & Campuses
Health Care
Educational Institutions
Travellers APPLICATIONS Some of the applications of Li-Fi are given below:
Medical field
Power plant
Traffic Lights
Under sea water ADVANTAGES of Wi-Fi.... Mobility
Easy of Installation
Good Flexibility
Use unlicensed part of the radio spectrum
Speed is high. DISADVANTAGE OF Wi-Fi.. Advantages of Li-Fi..... High Security
Easy To Use
Fast Data Transfer Reliable
Low Cost Interference
Degradation in performance
High power consumption
Limited range
Wi-Fi pollution:-
excessive number of hotspots in a area. ADVANTAGES and DISADVANTAGES Conclusion The possibilities are numerous and can be explored further. If his technology can be put into practical use, every bulb can be used something like a Wi-Fi hotspot to transmit wireless data and we will proceed toward the cleaner, greener, safer and brighter future. and The concept of Li-Fi is currently attracting a great deal of interest, not least because it may offer a genuine and efficient alternative to radio-based wireless. Any queries please? ,,Thank you allah,,
,,Thank you for coming ,,
,, Thank you MyFriends ,,
,,Thank you Dr. Nermeen Talaat,,
Full transcript