SE_EXTC MINI PROJECT future of wireless communication .pptx

second year project

1. RAM RAO ADIK INSTITUTE OF TECHNOLOGY DEPARTMENT OF ELECTRONICS AND TELECOMMUNICATION ENGINEERING MINI PROJECT -BY NAME ROLL NO. Abhishek Singh 19ET7009 Sairaj Pol 19ET7013 Anshuman Sengar 19ET7038 Omkar Salunke 19ET7043

2. LIGHT FIDELITY(Li-Fi) Future of wireless communication!

3. Contents Introduction to LI-FI History of LI-FI Implementation of LI-FI How it works! LI-FI vs WI-FI Applications Limitations Future Developments Conclusions

4. Introduction to LI-FI Li-Fi stands for Light Fidelity, which uses visible light as medium for data transmission. The Li-Fi system consists of normal LED light bulbs and modulating circuits. The idea of Li-Fi is to use existing light infrastructure to transmit data to our computer, Smartphones, tablets etc. This will eliminate some of the main limitations and disadvantages of traditional radio communication, such as Wi-Fi system that we use at home or office. Li-Fi utilizes LED light bulbs which are connected to a modulating circuit which will convert incoming data stream into rapidly flashing light. We human begins can’t perceive the high frequency flashing light but we will perceive a steady room lighting without any flicker. The receiver circuit can capture the high frequency flashing of LED and decodes it into understandable data stream for your computer or smartphone.

5. History The technology truly began during the year 1990’s in countries like Germany, Korea and Japan where they discovered LED’s could be retrofitted to send information. Prof. Harald Hass from university of Edinburgh, continues to wow the with the potential to use light for communication. He demonstrated in year 2012.

6. Implementation of LI-FI Components List: 3 x BC337 NPN Transistor 1 x 4.7K resistor 1 x 1K resistor 3 x 1000uF/25V electrolytic capacitor 1 x 1 Watt LED 1 x 100K Variable Resistor  1 x switch 1x 3V to 6V Solar cell        

7. Circuit Diagram

8. BLOCK DIAGRAM

9. How it works! The Li-Fi circuit serves two purposes: Room Lighting. Data transfer. While designing a Li-Fi circuit one must keep these two requirements in mind. Now consider the first requirement which is room lighting. The circuit must provide a steady lighting and must not flicker due to data transfer or the flicker rate must above our eyes persistence of vision while transferring data. The circuit proposed here has negligible flicker and always produce a steady brightness regardless of data transfer and still manage to transfer analog and digital data. You might wondering how can we transfer data without change in brightness? Actually there is very small change in brightness of the LED. The difference between maximum and minimum brightness of the LED is not perceivable to human eye because the difference is extremely small. The difference in the brightness can be detected by a solar cell easily, this can be witnessed by hooking a oscilloscope across its terminals and we can see the waveform peaks few millivolts.

10. The millivolts peaks from solar cell must be amplified adequately using  a USB computer speaker or any other good sensitive amplifier  so that it can drive a speaker. To keep the circuit simple as possible (to avoid multistage) of the transmitter, we have connected three low power transistor in parallel so that it can drive 1 watt LED with adequate current. The 4.7K and 1 K resistors provide necessary DC biasing for the three transistors which will put the transistors in  active mode  where the transistors acts as amplifier. We can spot the 4.7K resistor is connected in series with 100k variable resistor, this is to adjust the  quiescent current  of the amplifier (transmitter) thus adjusting the brightness of the LED. The quiescent current in the circuit is the reason why the LED stays ON regardless of the audio input. We have used the quiescent current to our advantage to glow the LED.

11. The receiver circuit is even simpler; make sure that you use a good sensitivity amplifier. The 3V to 6V solar cell can be used as light sensor,  you can use a good USB computer speaker to receive audio  or you can use any amplifier with good sensitivity.

12. Features LI-FI WI-FI Operation Interference Technology Applications Merits (advantages) Privacy Data transfer speed Li-Fi transmits data using light with the help of LED bulbs Do not have any interference issues similar to radio frequency waves. Present IrDA compliant devices. Used in airlines, undersea explorations, operation theatres in the hospitals for data transfer and internet browsing. Interference is less, can pass through salty sea water, works in dense region In Li-Fi, light is blocked by the walls and hence will provide more secure data transfer About 1 Gbps WLAN-11n offers 150 Mbps Wi-Fi transmits data using radio waves with the help of Wi-Fi router. Will have interference issues from nearby access points(routers). WLAN 802.11a/b/g/n/ac/ad standard compliant devices. Used for internet browsing with the help of Wi-Fi hotspots. Interference is more, cannot pass through sea water, works in less dense region In Wi-Fi, RF signal cannot be blocked by the walls and hence need to employ techniques to achieve secure data transfer. About 1 - 2 Gbps can be achieved using Wi-Gig/Giga-IR

13. Applications   Airplanes The best I‘ve heard so far is that passengers will "soon" be offered a "high-speed like"  connection on some airlines. United States is planning on speeds as high as 9.8 Mbps per plane. Smarter Power Plants Wi-Fi and many other radiation types are bad for sensitive areas. Like those surrounding power  plants. But power plants need fast, inter-connected data systems to monitor things like demand,  grid integrity and (in nuclear plants) core temperature..

14. Undersea Awesomeness Underwater ROVs, those favourite toys of treasure seekers and James Cameron, operate from large cables that supply their power and allow them to receive signals from their pilots above. ROVs work great, except when the tether isn‘t long enough to explore an area, or when it gets stuck on something. If their wires were cut and replaced with light — say from a submerged, high-powered lamp — then they would be much freer to explore. It Could Keep You Informed and Save Lives Say there‘s an earthquake in New Delhi, or a hurricane. Take your pick — it‘s a wacky city. The average Delhiite may not know what the protocols are for those kinds of disasters. Until they pass under a street light, that is. Remember, with Li-Fi, if there‘s light, you‘re online..

15. limitations 1) Radio waves have limited bandwidth: Due to increasing of wireless devices per person and emerging of internet of things (IoT) devices, allocating the radio frequencies is getting tighter day by day and licensing the radio spectrum costs enormous. 2) Restriction of Radio waves: You cannot always enjoy Wi-Fi internet in a hospital or in an airplane or in a place where the radio communications are restricted, because there could be interference with sensitive hospital equipments , which treats valuable patient’s life or very expensive experiment and interference of radio waves could alter the results. 3) Security: Wi-Fi can penetrate through walls and surround you area, you may say that my Wi-Fi is secured with a password but, a skilled black hat can break in to your network without any notice, and many of you are not good at setting a strong password for you router. 4) Health Hazard: High energetic radio waves are suspected to cause health issues; there are some people who complained that they are affected from high energetic radio waves.

16. Future development First applications of Li-Fi have been put to use already, for example, in hospitals where RF  signal are a threat due to interference problems with medical equipment such as blood pumps  and other life supporting instruments. Axiomtek Europe presented such a product at the  Embedded World exhibition in Nurnberg, Germany. The prototype of a mobile phone with an  incorporated VLC system was presented by Casio at the Consumer Electronics Show in Las  Vegas in January this year. In the coming years, we will see more Li-Fi products entering the  market, both in the industrial as well as consumer markets.

17. Conclusions The concept of Li-Fi is currently attracting a great deal of interest, not least because it may offer a genuine and very efficient alternative to radio-based wireless. As a growing number of people and their any devices access wireless internet, the airwaves are becoming increasingly clogged, making it more and more difficult to get a reliable, high-speed signal. This may solve issues such as the shortage of radio-frequency bandwidth and also allow internet where traditional radio based wireless isn‘t allowed such as aircraft or hospitals. One of the shortcomings however is that it only work in direct line of sight.

18. THANK YOU!