This document is a seminar report on Li-Fi (Light Fidelity) technology submitted by Vivek Kumar Jha. It includes an acknowledgement, certificate, contents, abstract, and sections on the introduction of Li-Fi, system design, present scenario of wireless communication, issues with radio waves, Li-Fi as an alternative, implementation of Li-Fi, overcoming issues, applications, and conclusion. The report provides an overview of Li-Fi technology which uses visible light communication through LED lights for wireless data transmission.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Lifi(Light fidelity)-Efficient use of visible spectruminventionjournals
ABSTRACT : LEDs are beginning to be used in every home and office which makes LED’s light ideal for ubiquitous data transmitter This means that everywhere where LEDs are used, lighting bulbs can bring not only the light but wireless connection at the same time. With increasing demand for wireless data, lack of radio spectrum and issues with hazardous electromagnetic pollution, LiFi is a new wireless communication technology which enables a wireless data transmission through LED light. LiFi appears as a new greener, healthier and cheaper alternative to WiFi. Li-Fi is the emerging area of technology is also known as Visible Light Commu-nications (VLC) .Moreover LiFi makes possible to have a wireless Internet in specific environments (hospitals, airplanes etc.) where WiFi is not allowed due to interferences or security considerations.
At the heart of this technology, a new generation of high-brightness light-emitting diodes. Very simply, if the LED is ON, user can transmit a digital string of 1, if it’s OFF then user can transmit a string of 0. It can be switched ON and OFF very quickly, which gives instant opportunity for transmitting data. It is possible to encode data in the light by varying the rate at which the LEDs flicker ON and OFF to pass different strings of 1s and 0s. The modulation is so fast that the human eye doesn’t notice. There are over 14 billion light bulbs used across the world, which needs to be replaced with LEDs ones that transmit data.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Lifi(Light fidelity)-Efficient use of visible spectruminventionjournals
ABSTRACT : LEDs are beginning to be used in every home and office which makes LED’s light ideal for ubiquitous data transmitter This means that everywhere where LEDs are used, lighting bulbs can bring not only the light but wireless connection at the same time. With increasing demand for wireless data, lack of radio spectrum and issues with hazardous electromagnetic pollution, LiFi is a new wireless communication technology which enables a wireless data transmission through LED light. LiFi appears as a new greener, healthier and cheaper alternative to WiFi. Li-Fi is the emerging area of technology is also known as Visible Light Commu-nications (VLC) .Moreover LiFi makes possible to have a wireless Internet in specific environments (hospitals, airplanes etc.) where WiFi is not allowed due to interferences or security considerations.
At the heart of this technology, a new generation of high-brightness light-emitting diodes. Very simply, if the LED is ON, user can transmit a digital string of 1, if it’s OFF then user can transmit a string of 0. It can be switched ON and OFF very quickly, which gives instant opportunity for transmitting data. It is possible to encode data in the light by varying the rate at which the LEDs flicker ON and OFF to pass different strings of 1s and 0s. The modulation is so fast that the human eye doesn’t notice. There are over 14 billion light bulbs used across the world, which needs to be replaced with LEDs ones that transmit data.
Today’s majority of data technique uses Radio Spectrum. But the major drawback of data
technique using radio spectrum is that it is very congested and the demand for wireless data
double each year. Every one, it seems want to use wireless data but the capacity is drying up.
Light –Fidelity is the transmission of data through illumination .It comprises of sending data
through a Light Emitting Diode which varies in intensity faster than human eye can follow .It
uses the fact that light travels at a such a high speed which is faster than human eye to catch.
Therefore when we vary the intensity of light emitting source it become impossible for the
humans to catch that sensation. It leads to very high speed data transmission, which is for
superior to current technologies.
Li-Fi stands for Light-Fidelity. Li-Fi is transmission of data using visible light by sending data through an LED light bulb that varies in intensity faster than the human eye can follow. If the LED is on, the photo detector registers a binary one; otherwise it‟s a binary zero. The idea of Li-Fi was introduced by a German physicist, Harald Hass, which he also referred to as “Data
through Illumination”. The term Li-Fi was first used by Haas in his TED Global talk on Visible Light Communication. According to Hass, the light, which he referred to as „DLight‟, can be used to produce data rates higher than 1 Giga bits per second which is much faster than our average broadband connection.
This Project discusses the implementation of the most basic Li-Fi based system to
transmit Sound signal from one device to another through visible light. The purpose is to demonstrate only the working of the simplest model of Li-Fi with no major consideration about the data transfer speed. This model will demonstrate how the notion of one-way communication via visible light works, in which Light emitting diodes (LEDs) are employed as the light sources or Transmitter antennas. the sound is transferred by light and is detected at the receiver without fading.
Whether you’re using wireless internet in a coffee shop, stealing it from the guy next door, or competing for
bandwidth at a conference, you’ve probably gotten frustrated at the slow speeds you face when more than one device is
tapped into the network. As more and more people and their many devices access wireless internet, clogged airwaves
are going to make it increasingly difficult to latch onto a reliable signal. But radio waves are just one part of the
spectrum that can carry our data. What if we could use other waves to surf the internet? One German physicist,DR.
Harald Haas, has come up with a solution he calls “Data Through Illumination”—taking the fiber out of fiber optics by
sending data through an LED light bulb that varies in intensity faster than the human eye can follow. It’s the same idea
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. He envisions a
future where data for laptops, smartphones, and tablets is transmitted through the light in a room. And security would be
a snap—if you can’t see the light, you can’t access the data. Li-Fi is a VLC, visible light communication, technology
developed by a team of scientists
Li-Fi stands for Light-Fidelity. Li-Fi is transmission of data using visible light by sending data through an LED light bulb that varies in intensity faster than the human eye can follow. If the LED is on, the photo detector registers a binary one; otherwise it’s a binary zero. The idea of Li-Fi was introduced by a German physicist, Harald Hass, which he also referred to as “Data through Illumination”. The term Li-Fi was first used by Haas in his TED Global talk on Visible Light Communication. According to Hass, the light, which he referred to as ‘DLight’, can be used to produce data rates higher than 1 Giga bits per second which is much faster than our average broadband connection.
Here a practical circuit to transfer audio signal is implemented
Light Fidelity (Li-Fi) is a bidirectional, high speed , fully networked wireless communication technology similar to Wi-Fi. Li-Fi was first put forward by Professor Harald Haas,University of Edinburgh, during a TED Talk in 2011. Li-Fi is a form of visible light communication and a subset of optical wireless communications (OWC) and could be a complement to RF communication (Wi-Fi or Cellular network), or even a replacement in contexts of data broadcasting. It is so far measured to be about 100 times faster than some Wi-Fi implementations, reaching speeds of 224 gigabits per second.
Li fi(led transmission of data) presentationKakashi57
LIFI –”LIGHT FIDEALITY” is transmission of data through illumination, i.e. sending data through a LED light bulb that varies in intensity faster than human eye can follow. Li-Fi is a light based Wi-Fi it uses light instead of radio waves to transmit information.
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 world with the potential to use light for communication He demonstrated in year 2012.
5. IMPLEMENTATION OF LI-FI The LI-FI product consists of three primary sub assemblies A. Emitter B. RF Driver C. Power Supply
6. FUNCTION OF BULB ASSEMBLY - At the heart of LI-FI is the bulb sub assembly where a sealed bulb is embedded in a dielectric material The dielectric material serves two purposes A. Wave guide B. Electric field
7. RF DRIVER - Power amplifier (PA) assembly that uses an LDMOS device. Converts electrical energy into RF power. The PA is designed to ruggedness and efficiency. The RF driver also contains controls circuit for digital and analog lighting controls.
8. HOW LI-FI WORKS- Operational procedure is very simple, if the LED is on, you transmit a digit 1, if its off you transmit a digit 0. the LED’s can be switched on and off quickly, which gives nice opportunities for transmitting data. hence all that us required is some LEDS and a controller that code data into those LEDs. We have to just vary the rate at which the LEDs flicker depending upon the data we want to encode. Thus every light source will work as a hub for data transmission. IMPLEMENTATION OF LI-FI The LI-FI product consists of three primary sub assemblies A. Emitter B. RF Driver C. Power Supply
6. FUNCTION OF BULB ASSEMBLY - At the heart of LI-FI is the bulb sub assembly where a sealed bulb is embedded in a dielectric material The dielectric material serves two purposes A. Wave guide B. Electric field
7. RF DRIVER - Power amplifier (PA) assembly that uses an LDMOS device. Converts electrical energy into RF power. The PA is designed to ruggedness and efficiency. The RF driver also contains controls circuit for digital and analog lighting controls.
8. HOW LI-FI WORKS- Operational procedure is very simple, if the LED is on, you transmit a digit 1, if its off you transmit a digit 0. the LED’s can be switched on and off quickly, which gives nice opportunities for transmitting data. hence all that us required is some LEDS and a controller that code data into those LEDs. We have to just vary the rate at which the LEDs flicker depending upon the data we want to encode. Thus every light source will work as a hub for data transmission
INTRODUCTION LiFi , also known as "Light Fidelity" is a wireless optical networking technology, which uses lightemitting diodes (LEDs) to transmit data. In 2011, professor Haas made a LiFi Harald demonstration at the TED (Technology, Entertainment, Design) Global Talk on Visible Light Communication (VLC).
LiFi (also known as light fidelity) is a technology for the wireless transmission of data between devices LiFi uses light as a medium for transmission of data. LED are the source used for encoding data by switching the light on and off during regular intervals to create a binary code.
Today’s majority of data technique uses Radio Spectrum. But the major drawback of data
technique using radio spectrum is that it is very congested and the demand for wireless data
double each year. Every one, it seems want to use wireless data but the capacity is drying up.
Light –Fidelity is the transmission of data through illumination .It comprises of sending data
through a Light Emitting Diode which varies in intensity faster than human eye can follow .It
uses the fact that light travels at a such a high speed which is faster than human eye to catch.
Therefore when we vary the intensity of light emitting source it become impossible for the
humans to catch that sensation. It leads to very high speed data transmission, which is for
superior to current technologies.
Li-Fi stands for Light-Fidelity. Li-Fi is transmission of data using visible light by sending data through an LED light bulb that varies in intensity faster than the human eye can follow. If the LED is on, the photo detector registers a binary one; otherwise it‟s a binary zero. The idea of Li-Fi was introduced by a German physicist, Harald Hass, which he also referred to as “Data
through Illumination”. The term Li-Fi was first used by Haas in his TED Global talk on Visible Light Communication. According to Hass, the light, which he referred to as „DLight‟, can be used to produce data rates higher than 1 Giga bits per second which is much faster than our average broadband connection.
This Project discusses the implementation of the most basic Li-Fi based system to
transmit Sound signal from one device to another through visible light. The purpose is to demonstrate only the working of the simplest model of Li-Fi with no major consideration about the data transfer speed. This model will demonstrate how the notion of one-way communication via visible light works, in which Light emitting diodes (LEDs) are employed as the light sources or Transmitter antennas. the sound is transferred by light and is detected at the receiver without fading.
Whether you’re using wireless internet in a coffee shop, stealing it from the guy next door, or competing for
bandwidth at a conference, you’ve probably gotten frustrated at the slow speeds you face when more than one device is
tapped into the network. As more and more people and their many devices access wireless internet, clogged airwaves
are going to make it increasingly difficult to latch onto a reliable signal. But radio waves are just one part of the
spectrum that can carry our data. What if we could use other waves to surf the internet? One German physicist,DR.
Harald Haas, has come up with a solution he calls “Data Through Illumination”—taking the fiber out of fiber optics by
sending data through an LED light bulb that varies in intensity faster than the human eye can follow. It’s the same idea
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. He envisions a
future where data for laptops, smartphones, and tablets is transmitted through the light in a room. And security would be
a snap—if you can’t see the light, you can’t access the data. Li-Fi is a VLC, visible light communication, technology
developed by a team of scientists
Li-Fi stands for Light-Fidelity. Li-Fi is transmission of data using visible light by sending data through an LED light bulb that varies in intensity faster than the human eye can follow. If the LED is on, the photo detector registers a binary one; otherwise it’s a binary zero. The idea of Li-Fi was introduced by a German physicist, Harald Hass, which he also referred to as “Data through Illumination”. The term Li-Fi was first used by Haas in his TED Global talk on Visible Light Communication. According to Hass, the light, which he referred to as ‘DLight’, can be used to produce data rates higher than 1 Giga bits per second which is much faster than our average broadband connection.
Here a practical circuit to transfer audio signal is implemented
Light Fidelity (Li-Fi) is a bidirectional, high speed , fully networked wireless communication technology similar to Wi-Fi. Li-Fi was first put forward by Professor Harald Haas,University of Edinburgh, during a TED Talk in 2011. Li-Fi is a form of visible light communication and a subset of optical wireless communications (OWC) and could be a complement to RF communication (Wi-Fi or Cellular network), or even a replacement in contexts of data broadcasting. It is so far measured to be about 100 times faster than some Wi-Fi implementations, reaching speeds of 224 gigabits per second.
Li fi(led transmission of data) presentationKakashi57
LIFI –”LIGHT FIDEALITY” is transmission of data through illumination, i.e. sending data through a LED light bulb that varies in intensity faster than human eye can follow. Li-Fi is a light based Wi-Fi it uses light instead of radio waves to transmit information.
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 world with the potential to use light for communication He demonstrated in year 2012.
5. IMPLEMENTATION OF LI-FI The LI-FI product consists of three primary sub assemblies A. Emitter B. RF Driver C. Power Supply
6. FUNCTION OF BULB ASSEMBLY - At the heart of LI-FI is the bulb sub assembly where a sealed bulb is embedded in a dielectric material The dielectric material serves two purposes A. Wave guide B. Electric field
7. RF DRIVER - Power amplifier (PA) assembly that uses an LDMOS device. Converts electrical energy into RF power. The PA is designed to ruggedness and efficiency. The RF driver also contains controls circuit for digital and analog lighting controls.
8. HOW LI-FI WORKS- Operational procedure is very simple, if the LED is on, you transmit a digit 1, if its off you transmit a digit 0. the LED’s can be switched on and off quickly, which gives nice opportunities for transmitting data. hence all that us required is some LEDS and a controller that code data into those LEDs. We have to just vary the rate at which the LEDs flicker depending upon the data we want to encode. Thus every light source will work as a hub for data transmission. IMPLEMENTATION OF LI-FI The LI-FI product consists of three primary sub assemblies A. Emitter B. RF Driver C. Power Supply
6. FUNCTION OF BULB ASSEMBLY - At the heart of LI-FI is the bulb sub assembly where a sealed bulb is embedded in a dielectric material The dielectric material serves two purposes A. Wave guide B. Electric field
7. RF DRIVER - Power amplifier (PA) assembly that uses an LDMOS device. Converts electrical energy into RF power. The PA is designed to ruggedness and efficiency. The RF driver also contains controls circuit for digital and analog lighting controls.
8. HOW LI-FI WORKS- Operational procedure is very simple, if the LED is on, you transmit a digit 1, if its off you transmit a digit 0. the LED’s can be switched on and off quickly, which gives nice opportunities for transmitting data. hence all that us required is some LEDS and a controller that code data into those LEDs. We have to just vary the rate at which the LEDs flicker depending upon the data we want to encode. Thus every light source will work as a hub for data transmission
INTRODUCTION LiFi , also known as "Light Fidelity" is a wireless optical networking technology, which uses lightemitting diodes (LEDs) to transmit data. In 2011, professor Haas made a LiFi Harald demonstration at the TED (Technology, Entertainment, Design) Global Talk on Visible Light Communication (VLC).
LiFi (also known as light fidelity) is a technology for the wireless transmission of data between devices LiFi uses light as a medium for transmission of data. LED are the source used for encoding data by switching the light on and off during regular intervals to create a binary code.
In Wireless communication, Wi Fi is the most versatile and effective technology which compact with radio frequencies for data transmission. But because of multiple accesses Wi Fi is facing many challenges namely capacity, availability, efficiency and security. The Wi Fi emits radio waves which are very harmful for the patients and the radio waves interpret the medical instruments. This paper focuses on developing a light fidelity Li Fi based system and analyzing its performance. This protocol can be adapted where radio waves are restricted, such as airplanes hospitals, and in some research facilities. Li Fi is a novel technology for high density wireless data transfer relieving no radio interferences in confined areas so it can be used in biosensors to measure various health parameters. This technology envisions a future where data for laptops, smart phones, and tablets will be transmitted in an economic and eco friendly medium of light in room. Bolli Jagadeeswari | Charapu Sai Anusha | Dangeti Monisa | Medisetti Preethi ""Audio Transmission using Li-Fi Technology"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23156.pdf
Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/23156/audio-transmission-using-li-fi-technology/bolli-jagadeeswari
Light–Fidelity (Li-Fi) is a technology that uses the Light Emitting Diodes (LEDs) to transmit wireless data instead of radio waves.
This is going to be the future of wireless data transmission.
Smart phones, tablets, and the rise of the Internet of Things are driving an insatiable demand for wireless capacity. This demand requires networking and Internet infrastructures to evolve to meet the needs of current and future multimedia applications. Wireless HetNets will play an important role toward the goal of using a diverse spectrum to provide high quality-of-service, especially in indoor environments where most data are consumed. An additional tier in the wireless HetNets concept is envisioned using indoor gigabit small-cells to offer additional wireless capacity where it is needed the most. The use of light as a new mobile access medium is considered promising. In this article, we describe the general characteristics of WiFi and VLC (or LiFi) and demonstrate a practical framework for both technologies to coexist. We explore the existing research activity in this area and articulate current and future research challenges based on our experience in building a proof-of-concept prototype VLC HetNet.
This paper attempts to clarify the difference between visible light communication (VLC) and Light-Fidelity (LiFi). In particular, it will show how LiFi takes VLC further by using light emitting diodes (LEDs) to realise fully networked wireless systems. Synergies are harnessed as luminaries become LiFi attocells resulting in enhanced wireless capacity providing the necessary connectivity to realise the Internet-of-Things (IoT), and contributing to the key performance indicators for the 5th generation of cellular systems (5G) and beyond
Li-Fi is a new wireless technology which provides the connectivity within localized network environment. The main principle of this technology is we can transmit the data using light illumination by using light emitting diodes where radio frequency is media in Wi-Fi and LED bulb light intensity is faster than human eye can follow. One germen phycist-Prof Harald Haas an expert in optical wireless communications at the University of Edinburgh, he demonstrated how an LED bulb equipped with signal processing technology could stream a high-definition video to a computer. By using this technology a one-watt LED light bulb would be enough to provide net connectivity to four computers. He coined the term "light fidelity" or Li-Fi. He visualizes a future where data for laptops, Smartphone, and tablets is transmitted through the light in a room. This technology is still under research and further exploitation could lead to wide applications.
Conceptual Design of LiFi Audio Transmission Using Pre-Programmed ModulesAuwal Amshi
We design a concept of Li-fi audio signal transmission by reusing and repurposing pre-programmed modules to simplify and discuss visible light communication (VLC) in other to give a new researcher the idea on how the concept of LiFi and VLC.
Li-Fi can be thought of as a light-based Wi-Fi. That is, it uses light instead of radio waves to transmit information. And instead of Wi-Fi modems, Li-Fi would use transceiver-fitted LED lamps that can light a room as well as transmit and receive information. Since simple light bulbs are used, there can technically be any number of access points.
What is sensitive skin?
It is a large area flexible array of sensors, with data processing capabilities, with the ability to sense the surroundings.
It make possible the use of unsupervised machine in our midst.
Machines in unstructured environments
Societal needs and concerns
a) Health industry
b) Eco friendly
c) Difficulties of acceptance
Brain fingerprinting is based on finding that the brain generates a unique brain wave pattern when a person encounters a familiar stimulus Use of functional magnetic resonance imaging in lie detection derives from studies suggesting that persons asked to lie show different patterns of brain activity than they do when being truthful. Issues related to the use of such evidence in courts are discussed. The author concludes that neither approach is currently supported by enough data regarding its accuracy in detecting deception to warrant use in court.
In the field of criminology, a new lie detector has been developed in the United States of America. This is called “brain fingerprinting”. This invention is supposed to be the best lie detector available as on date and is said to detect even smooth criminals who pass the polygraph test (the conventional lie detector test) with ease. The new method employs brain waves, which are useful in detecting whether the person subjected to the test, remembers finer details of the crime. Even if the person willingly suppresses the necessary information, the brain wave is sure to trap him, according to the experts, who are very excited about the new kid on the block.
Fingerprinting is a controversial proposed investigative technique that measures recognition of familiar stimuli by measuring electrical brain wave responses to words, phrases, or pictures that are presented on a computer screen. Brain fingerprinting was invented by Lawrence Farwell. The theory is that the suspect's reaction to the details of an event or activity will reflect if the suspect had prior knowledge of the event or activity. This test uses what Farwell calls the MERMER ("Memory and Encoding Related Multifaceted Electroencephalographic Response") response to detect familiarity reaction. One of the applications is lie detection. Dr. Lawrence A. Farwell has invented, developed, proven, and patented the technique of Farwell Brain Fingerprinting, a new computer-based technology to identify the perpetrator of a crime accurately and scientifically by measuring brain-wave responses to crime-relevant words or pictures presented on a computer screen. Farwell Brain Fingerprinting has proven 100% accurate in over 120 tests, including tests on FBI agents, tests for a US intelligence agency and for the US Navy, and tests on real-life situations including actual crimes.
Abstract:
Brain fingerprinting is based on finding that the brain generates a unique brain wave pattern when a person encounters a familiar stimulus Use of functional magnetic resonance imaging in lie detection derives from studies suggesting that persons asked to lie show different patterns of brain activity than they do when being truthful. Issues related to the use of such evidence in courts are discussed. The author concludes that neither approach is currently supported by enough data regarding its accuracy in detecting deception to warrant use in court.
In the field of criminology, a new lie detector has been developed in the United States of America. This is called “brain fingerprinting”. This invention is supposed to be the best lie detector available as on date and is said to detect even smooth criminals who pass the polygraph test (the conventional lie detector test) with ease. The new method employs brain waves, which are useful in detecting whether the person subjected to the test, remembers finer details of the crime. Even if the person willingly suppresses the necessary information, the brain wave is sure to trap him, according to the experts, who are very excited about the new kid on the block.
Introduction:
Brain Fingerprinting is a controversial proposed investigative technique that measures recognition of familiar stimuli by measuring electrical brain wave responses to words, phrases, or pictures that are presented on a computer screen. Brain fingerprinting was invented by Lawrence Farwell. The theory is that the suspect's reaction to the details of an event or activity will reflect if the suspect had prior knowledge of the event or activity. This test uses what Farwell calls the MERMER ("Memory and Encoding Related Multifaceted Electroencephalographic Response") response to detect familiarity reaction. One of the applications is lie detection. Dr. Lawrence A. Farwell has invented, developed, proven, and patented the technique of Farwell Brain Fingerprinting, a new computer-based technology to identify the perpetrator of a crime accurately and scientifically by measuring brain-wave responses to crime-relevant words or pictures presented on a computer screen. Farwell Brain Fingerprinting has proven 100% accurate in over 120 tests, including tests on FBI agents, tests for a US intelligence agency and for the US Navy, and tests on real-life situations including actual crimes..
Brain fingerprinting is based on finding that the brain generates a unique brain wave pattern when a person encounters a familiar stimulus Use of functional magnetic resonance imaging in lie detection derives from studies suggesting that persons asked to lie show different patterns of brain activity than they do when being truthful. Issues related to the use of such evidence in courts are discussed. The author concludes that neither approach is currently supported by enough data regarding its accuracy in detecting deception to warrant use in court.
In the field of criminology, a new lie detector has been developed in the United States of America. This is called “brain fingerprinting”. This invention is supposed to be the best lie detector available as on date and is said to detect even smooth criminals who pass the polygraph test (the conventional lie detector test) with ease. The new method employs brain waves, which are useful in detecting whether the person subjected to the test, remembers finer details of the crime. Even if the person willingly suppresses the necessary information, the brain wave is sure to trap him, according to the experts, who are very excited about the new kid on the block.
Fingerprinting is a controversial proposed investigative technique that measures recognition of familiar stimuli by measuring electrical brain wave responses to words, phrases, or pictures that are presented on a computer screen. Brain fingerprinting was invented by Lawrence Farwell. The theory is that the suspect's reaction to the details of an event or activity will reflect if the suspect had prior knowledge of the event or activity. This test uses what Farwell calls the MERMER ("Memory and Encoding Related Multifaceted Electroencephalographic Response") response to detect familiarity reaction. One of the applications is lie detection. Dr. Lawrence A. Farwell has invented, developed, proven, and patented the technique of Farwell Brain Fingerprinting, a new computer-based technology to identify the perpetrator of a crime accurately and scientifically by measuring brain-wave responses to crime-relevant words or pictures presented on a computer screen. Farwell Brain Fingerprinting has proven 100% accurate in over 120 tests, including tests on FBI agents, tests for a US intelligence agency and for the US Navy, and tests on real-life situations including actual crimes.
Blue Gene_SM
Introduction
The word "supercomputer" entered the mainstream lexicon in 1996 and 1997 when IBM's Deep Blue supercomputer challenged the world chess champion in two tournaments broadcast around the world.
Since then, IBM has been busy improving its supercomputer technology and tackling much deeper problems.
Their latest project, code named Blue Gene, is poised to shatter all records for computer and network performance.
What is a Super Computer
A supercomputer is a computer that is at the frontline of current processing capacity, particularly speed of calculation.
Today, supercomputers are typically one-of-a-kind custom designs produced by "traditional" companies such as Cray, IBM and Hewlett-Packard, who had purchased many of the 1980s companies to gain their experience.
Why we need Super Computers
Supercomputers are very useful in highly calculation-intensive tasks such as
Problems involving quantum physics,
Weather forecasting,
Climate research,
Molecular modeling (computing the structures and properties of chemical compounds, biological macromolecules, polymers, and crystals),
Physical simulations (such as simulation of airplanes in wind tunnels, simulation of the detonation of nuclear weapons, and research into nuclear fusion).
Why we need Super Computers
Also, they are useful for a particular class of problems, known as Grand Challenge problems, full solution for such problems require semi-infinite computing resources.
NASA™s Linux-based Super Computer
Why Supercomputers are Fast
Several elements of a supercomputer contribute to its high level of performance:
Numerous high-performance processors (CPUs) for parallel processing
Specially-designed high-speed internal networks
Specially-designed or tuned operating systems
What is Blue gene
Blue Gene is a computer architecture project designed to produce several supercomputers that are designed to reach operating speeds in the PFLOPS (petaFLOPS = 1015) range, and currently reaching sustained speeds of nearly 500 TFLOPS (teraFLOPS = 1012).
It is a cooperative project among IBM(particularly IBM Rochester and the Thomas J. Watson Research Center), the Lawrence Livermore National Laboratory, the United States Department of Energy (which is partially funding the project), and academia.
Why Blue Gene
Blue Gene is an IBM Research project dedicated to exploring the
frontiers in supercomputing:
in computer architecture,
in the software required to program and control massively parallel systems, and
in the use of computation to advance the understanding of important biological processes such as protein folding.
Learning more about biomolecular mechanisms is expected to give medical researchers better understanding of diseases, as well as potential cures.
Why the name Blue gene
Blue - The corporate color of IBM
Gene - The intended use of the Blue Gene clusters was for Computational biology.
Blue Gene Projects
Blue Gene_SM
Introduction
The word "supercomputer" entered the mainstream lexicon in 1996 and 1997 when IBM's Deep Blue supercomputer challenged the world chess champion in two tournaments broadcast around the world.
Since then, IBM has been busy improving its supercomputer technology and tackling much deeper problems.
Their latest project, code named Blue Gene, is poised to shatter all records for computer and network performance.
What is a Super Computer
A supercomputer is a computer that is at the frontline of current processing capacity, particularly speed of calculation.
Today, supercomputers are typically one-of-a-kind custom designs produced by "traditional" companies such as Cray, IBM and Hewlett-Packard, who had purchased many of the 1980s companies to gain their experience.
Why we need Super Computers
Supercomputers are very useful in highly calculation-intensive tasks such as
Problems involving quantum physics,
Weather forecasting,
Climate research,
Molecular modeling (computing the structures and properties of chemical compounds, biological macromolecules, polymers, and crystals),
Physical simulations (such as simulation of airplanes in wind tunnels, simulation of the detonation of nuclear weapons, and research into nuclear fusion).
Why we need Super Computers
Also, they are useful for a particular class of problems, known as Grand Challenge problems, full solution for such problems require semi-infinite computing resources.
NASA™s Linux-based Super Computer
Why Supercomputers are Fast
Several elements of a supercomputer contribute to its high level of performance:
Numerous high-performance processors (CPUs) for parallel processing
Specially-designed high-speed internal networks
Specially-designed or tuned operating systems
What is Blue gene
Blue Gene is a computer architecture project designed to produce several supercomputers that are designed to reach operating speeds in the PFLOPS (petaFLOPS = 1015) range, and currently reaching sustained speeds of nearly 500 TFLOPS (teraFLOPS = 1012).
It is a cooperative project among IBM(particularly IBM Rochester and the Thomas J. Watson Research Center), the Lawrence Livermore National Laboratory, the United States Department of Energy (which is partially funding the project), and academia.
Why Blue Gene
Blue Gene is an IBM Research project dedicated to exploring the
frontiers in supercomputing:
in computer architecture,
in the software required to program and control massively parallel systems, and
in the use of computation to advance the understanding of important biological processes such as protein folding.
Learning more about biomolecular mechanisms is expected to give medical researchers better understanding of diseases, as well as potential cures.
Why the name Blue gene
Blue - The corporate color of IBM
Gene - The intended use of the Blue Gene clusters was for Computational biology.
Blue Gene Projects
There
Smart Note Taker is a helpful product that satisfies the needs of the people in today's technologic and fast life. This product can be used in many ways. The Smart Note Taker provides taking fast and easy note making to people who are busy with one's self.
With the help of Smart Note Taker, people will be able to write notes in air, while being busy with their work. The written note will be stored in the memory chip of the pen, and will be able to read in digital medium after the job is done. This saves time and facilitate life.
This product is simple but powerful. It has the ability to sense 3D shapes and motions that the user tries to draw. The sensed information will be processed and transferred to the memory chip and then will be monitored on the display device. The shape that is drawn can be broadcasted to the network or sent to a mobile device.
Smart Note Taker is a helpful product that satisfies the needs of the people in today's technologic and fast life. This product can be used in many ways. The Smart Note Taker provides taking fast and easy note making to people who are busy with one's self.
With the help of Smart Note Taker, people will be able to write notes in air, while being busy with their work. The written note will be stored in the memory chip of the pen, and will be able to read in digital medium after the job is done. This saves time and facilitate life.
This product is simple but powerful. It has the ability to sense 3D shapes and motions that the user tries to draw. The sensed information will be processed and transferred to the memory chip and then will be monitored on the display device. The shape that is drawn can be broadcasted to the network or sent to a mobile device.
Li-Fi is transmission of data through illumination by taking thefiber out of fiber optics by sending data through a LED lightbulb that varies in intensity faster than the human eye canfollow.
“At the heart of this technology is a newgeneration of high brightness light-emitting diodes”, saysHarald Haas from the University of Edinburgh, UK.”Verysimply, if the LED is on, you transmit a digital 1,
if it’s offyou transmit a 0,”Haas says, “They can be switched on and offvery quickly, which gives nice opportunities for transmitteddata.”
It is possible to encode data in the light by varying therate at which the LEDs flicker on and off to give differentstrings of 1s and 0s.The LED intensity is modulated so rapidlythat human eye cannot notice, so the output appears constant.
More sophisticated techniques could dramatically increaseVLC data rate. Terms at the University of Oxford and theUniversity of Edinburgh are focusing on parallel datatransmission using array of LEDs, where each LED transmits a different data stream. Other groups are using mixtures of red,green and blue LEDs to alter the light frequency encoding adifferent data channel.
Li-Fi, as it has been dubbed, has alreadyachieved blisteringly high speed in the lab. Researchers at theHeinrich Hertz Institute in Berlin, Germany have reached datarates of over 500 megabytes per second using a standardwhite-light LED.
Li-Fi is typically implemented using white LED light bulbs at the downlink transmitter. These devices are normally used for illumination only by applying a constant current. However, by fast and subtle variations of the current, the optical output can be made to vary at extremely high speeds. This very property of optical current is used in Li-Fi setup.The operational procedure is very simple-,data from the internet and local network is used to modulate the intensity of the LED light source if any undetectable to the human eye. The photo detector picks up signal, which is converted back into a data stream and sent to the client.
The client can communicate through its own LED output or over the existing network. An overhead lamp fitted with an LED with signal-processing technology streams data embedded in its beam at ultra-high speeds to the photo-detector. A receiver dongle then converts the tiny changes in amplitude into an electrical signal, which is then converted back into a data stream and transmitted to a computer or mobile device.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Generating a custom Ruby SDK for your web service or Rails API using Smithyg2nightmarescribd
Have you ever wanted a Ruby client API to communicate with your web service? Smithy is a protocol-agnostic language for defining services and SDKs. Smithy Ruby is an implementation of Smithy that generates a Ruby SDK using a Smithy model. In this talk, we will explore Smithy and Smithy Ruby to learn how to generate custom feature-rich SDKs that can communicate with any web service, such as a Rails JSON API.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Epistemic Interaction - tuning interfaces to provide information for AI support
Li fi report
1. Li-Fi
2013
Li-Fi:
The latest tech in Wireless Communication
A Seminar Project Report submitted by: Vivek Kumar Jha
in partial fulfillment for the award of the degree of
Bachelor in Technology in Computer Science & Engg.
under the able guidance of Ms. Sarita Das (Project
Guide) & Ms. Nalini Prabha Behera (HOD, CSE).
2. 1
Acknowledgement
I take this opportunity to express my deep sense of gratitude
and thankfulness to my project guide, Ms. Sarita Das
andMs. Nalini Prabha Behera(HOD, CSE) under whose
able guidance I have been successful in finishing the project
work.
Vivek Kumar Jha
Regd. No – 1001215240
Branch – CSE
EAST
3. 2
Certificate
This is to certify that Master Vivek Kumar Jha, 6th Sem, CSE Branch
has completed & duly submitted his seminar report hard copy
correctly within the stipulated time. His work was found to be
genuine & correct.
Ms. N.P. Behera Ms. Sarita Das Ms. S. Mishra
(H.O.D, CSE) (Project Guide) (Principal, EAST)
5. 4
Abstract
hether you’re using wireless internet in a coffee
shop,stealing it from the guy next door, or competing for
bandwidth at a conference, you have probably gotten
frustrated at the slow speeds you face when more than one device is
tapped into the network. As more and more people and their
manydevices access wireless internet, clogged airwaves are going
tomake it.
One German physicist, Harald Haas has come up with asolution he
calls “data through illumination” –taking the fibberout of fiber optic by
sending data through an LED light bulbthat varies in intensity faster
than the human eye can follow.It’s the same idea band behind infrared
remote controls but farmore powerful.
Haas says his invention, which he calls D-Light,can produce data rates
faster than 10 megabits persecond, which is speedier than your average
broadbandconnection. He envisions a future where data for
laptops,smart phones, and tablets is transmitted through the light in
aroom. And security would be snap – if you can’t see the light,you can’t
access the data.
W
6. 5
Introduction to Li-Fi
i-Fi is transmission of data through illumination by taking
thefiber out of fiber optics by sending data through a LED
lightbulb that varies in intensity faster than the human eye
canfollow.
“At the heart of this technology is a newgeneration of high brightness
light-emitting diodes”, saysHarald Haas from the University of
L
7. 6
Edinburgh, UK.”Verysimply, if the LED is on, you transmit a digital 1,
if it’s offyou transmit a 0,”Haas says, “They can be switched on and
offvery quickly, which gives nice opportunities for transmitteddata.”
It is possible to encode data in the light by varying therate at which the
LEDs flicker on and off to give differentstrings of 1s and 0s.The LED
intensity is modulated so rapidlythat human eye cannot notice, so the
output appears constant.
More sophisticated techniques could dramatically increaseVLC data
rate. Terms at the University of Oxford and theUniversity of Edinburgh
are focusing on parallel datatransmission using array of LEDs, where
each LED transmits a different data stream. Other groups are using
mixtures of red,green and blue LEDs to alter the light frequency
encoding adifferent data channel.
Li-Fi, as it has been dubbed, has alreadyachieved blisteringly high
speed in the lab. Researchers at theHeinrich Hertz Institute in Berlin,
Germany have reached datarates of over 500 megabytes per second
using a standardwhite-light LED.
8. 7
System Design
Li-Fi is typically implemented using white LED light bulbs at the
downlink transmitter. These devices are normally used for illumination
only by applying a constant current. However, by fast and subtle
variations of the current, the optical output can be made to vary at
extremely high speeds. This very property of optical current is used in
Li-Fi setup.The operational procedure is very simple-,data from the
internet and local network is used to modulate the intensity of the LED
light source if any undetectable to the human eye. The photo detector
picks up signal, which is converted back into a data stream and sent to
the client.
The client can communicate through its own LED output or over the
existing network. An overhead lamp fitted with an LED with signal-
processing technology streams data embedded in its beam at ultra-high
speeds to the photo-detector. A receiver dongle then converts the tiny
changes in amplitude into an electrical signal, which is then converted
back into a data stream and transmitted to a computer or mobile
device.
10. 9
Methods of Visible Light Communication
Devices used for Visible Light Communication
Communication using Image Sensors
Devices used for Visible Light Communication
Transmitter Device Receiver Device
Methods of Visible Light Communication
Transmitter device of visible light communication
Visible Light LED
LED light intensity is modulated by controlling its current.
Data rate: low speed to very high speed (up to several hundred
Mbps)
Visible Light
11. 10
Visible Light LED
Fluorescent Lamp
FSK modulation of high frequency fluorescent light.
Data rate: up to several kilo bps.
Fluorescent Lamp
Receiver device of visible light communication
PIN photo diode:
A PIN diode is a diode with a wide, lightly doped 'near' intrinsic
semiconductor region between a p-type semiconductor and an n-type
semiconductor region. The p-type and n-type regions are typically
heavily doped because they are used for Ohmic contacts.
The wide intrinsic region is in contrast to an ordinary PN diode. The
wide intrinsic region makes the PIN diode an inferior rectifier (one
typical function of a diode), but it makes the PIN diode suitable for
12. 11
attenuators, fast switches, photo detectors, and high voltage power
electronics applications.
Operation:
A PIN diode operates under what is known as high-level injection.
In other words, the intrinsic "i" region is flooded with charge carriers
from the "p" and "n" regions. Its function can be likened to filling up a
water bucket with a hole on the side. Once the water reaches the hole's
level it will begin to pour out. Similarly, the diode will conduct current
once the flooded electrons and holes reach an equilibrium point, where
the number of electrons is equal to the number of holes in the intrinsic
region. When the diode is forward biased, the injected carrier
concentration is typically several orders of magnitude higher than the
intrinsic level carrier concentration. Due to this high level injection,
which in turn is due to the depletion process, the electric field extends
deeply (almost the entire length) into the region. This electric field
helps in speeding up of the transport of charge carriers from P to N
region, which results in faster operation of the diode, making it
a suitable device for high frequency operations.
13. 12
PIN photodiode
Avalanche photo diode
An avalanche photodiode (APD) is a highly sensitive
semiconductor electronic device that exploits the photoelectric effect to
convert light to electricity. APDs can be thought of as photo
detectors that provide a built-in first stage of gain through avalanche
multiplication. From a functional standpoint, they can be regarded as
the semiconductor analog to photo multipliers.By applying a high
reverse bias voltage (typically 100-200 V in silicon), APDs show an
internal current gain effect (around 100) due to impact
ionization (avalanche effect). However, some silicon APDs employ
alternative doping and beveling techniques compared to traditional
APDs that allow greater voltage to be applied (> 1500 V) before
breakdown is reached and hence a greater operating gain (> 1000).In
general, the higher the reverse voltage the higher the gain.
14. 13
Figure-2.6: Avalanche photo diode
APD applicability and usefulness depends on many parameters.
Two of the larger factors are: quantum efficiency, which indicates how
well incident optical photons are absorbed and then used to generate
primary charge carriers; and total leakage current, which is the sum of
the dark current and photocurrent and noise. Electronic dark noise
components are series and parallel noise. Series noise, which is the
effect of shot noise, is basically proportional to the APD capacitance
while the parallel noise is associated with the fluctuations of the APD
bulk and surface dark currents. Another noise source is the excess
noise factor, F. It describes the statistical noise that is inherent with the
stochastic APD multiplication process.
Image sensor
An image sensor is a device that converts an optical image into
an electronic signal. It is used mostly in digital cameras, camera
modules and other imaging devices. Early analog sensors were video
camera tubes; most currently used are digital charge-coupled
15. 14
device (CCD) or complementary metal–oxide–semiconductor
(CMOS) active pixel sensors.
Image sensor
Communication using Image Sensors
Principles of communication using image sensor
16. 15
Principles of Communication Using Image
Sensor
Camera (receiver) continuously takes images of a scene with an LED
light and a receiver detects the optical intensity at a pixel where the
LED light is focused on.
Even if multiple visible light sources send data simultaneously, an
image sensor is able to receive and demodulate all the data
simultaneously without any interference between them.
Merits of communication using image sensor
Number of signal: Multiple.
Robustness: no cross talk/no Interference.
Distance: Very Long (2km).
Space Resolution: Each pixel.
17. 16
Areas to which visible light communication technology may be
applied
Applications that do personal area communication.
Applications that enable users to know users locations in
several meter accuracy.
Applications that enable users to know users locations in
several millimeter accuracy.
Applications that use augmented reality.
Applications that cannot be achieved by radio-wave technology.
Present Scenario
We have 1.4million cellular mast radio waves base stations
deployed.
We also have over 5 billions of mobile phones.
Mobile phone transmits more than 600 Tb of data.
Wireless communication has become a utility like electricity &
water.
We use it in our everyday life, in our private life, business life.
Currently Wi-Fi uses Radio Waves for communication.
It is important to look into this technology which has become
fundamental to our life.
18. 17
Four Issues with Radio Waves
1.Capacity:
Radio waves are limited.
Radio waves are scarce and expensive.
We only have a certain range of it.
With the advent of the new generation technologies like
2.5G, 3G, 4G and so on we are running out of spectrum.
2. Efficiency:
There are 1.4 million cellular radio base stations.
They consume massive amount of energy.
Most of this energy is not used for transmission but for
cooling down the base stations.
Efficiency of such a base station is only 5%.
3. Availability:
Availability of radio waves is another cause of concern.
We have to switch off our mobiles in aero planes.
It is not advisable to use mobiles at places like petrochemical
plants and petrol pumps.
4. Security:
Radio waves penetrate through walls.
They can be intercepted.
19. 18
If someone has knowledge and bad intentions then he may
misuse it.
Alternative to Radio Waves in electromagnetic
Spectrum
There are four major concerns i.e., capacity, efficiency,
availability and security related with Radio waves.
But on the other hand we have 40 billions of light box already
installed and light is the part of electromagnetic spectrum.
Gamma rays are simply very dangerous and thus can’t be used for our
purpose of communication.
X-rays are good in hospitals and can’t be used either.
Ultra-violet rays are good for getting a sun-tan but exposure for long duration
is dangerous.
Infrared rays are bad for our eyes and are therefore used at low power levels.
We have already seen the shortcomings of Radio waves.
So we are left with only Visible Light Spectrum.
20. 19
Also if we see the spectrum band of visible light than we will find that it
is 10000 times more than that of radio waves.
21. 20
Light for Wireless Communication
Light has been around for millions of years.
It has created us created life and has created all stuffs of life.
Visible light Communication (VLC) uses rapid pulses of light to
transmit information wirelessly. Now it may be ready to compete
with conventional Wi-Fi.
So it is inherently safe to use for wireless communication.
IMPLEMENTATION
This brilliant idea was first showcased by Harald Haas from University
of Edinburgh, UK, in his TED Global talk on VLC. He explained,” 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.” So what you require at all are
some LEDs and a controller that code data into those LEDs. We have to
just vary the rate at which the LED’s flicker depending upon the data
we want to encode. Further enhancements can be made in this method,
like using an array of LEDs for parallel data transmission, or using
mixtures of red, green and blue LEDs to alter the light’s frequency with
each frequency encoding a different data channel.
Such advancements promise a theoretical speed of 10Gbps–
meaning you can download a full high-definition film in just 30
22. 21
seconds. Simply awesome! But blazingly fast data rates and depleting
bandwidths worldwide are not the only reasons that give this
technology an upper hand. Since Li-Fi uses just the light, it can be used
safely in aircrafts and hospitals that are prone to interference from
radio waves. This can even work underwater where Wi-Fi fails
completely, thereby throwing open endless opportunities for military
operations.
Imagine only needing to hover under a street lamp to get public
internet access, or downloading a movie from the lamp on your desk.
There's a new technology on the block which could, quite literally as
well as metaphorically, 'throw light on' how to meet the ever-increasing
demand for high-speed wireless connectivity. Radio waves are replaced
by light waves in a new method of data transmission which is being
called Li-Fi. Light-emitting diodes can be switched on and off faster
than the human eye can detect, causing the light source to appear to be
on continuously. A flickering light can be incredibly annoying, but has
turned out to have its upside, being precisely what makes it possible to
use light for wireless data transmission. Light-emitting diodes
(commonly referred to as LEDs and found in traffic and street lights,
car brake lights, remote control units and countless other applications)
can be switched on and off faster than the human eye can detect,
causing the light source to appear to be on continuously, even though it
is in fact 'flickering'. This invisible on-off activity enables a kind of data
transmission using binary codes: switching on an LED is a logical '1',
23. 22
switching it off is a logical '0'. Information can therefore be encoded in
the light by varying the rate at which the LEDs flicker on and off to give
different strings of 1s and 0s. This method of using rapid pulses of light
to transmit information wirelessly is technically referred to as Visible
Light Communication (VLC), though it’s potential to compete with
conventional Wi-Fi has inspired the popular characterization Li-Fi.
Visible light communication “A potentialsolution
to the global wireless spectrum shortage”
Li-Fi (Light Fidelity) is a fast and cheap optical version of Wi-Fi, the
technology of which is based on Visible Light Communication
(VLC).VLC is a data communication medium, which uses visible light
between 400 THz (780 nm) and 800 THz (375 nm) as optical carrier
for data transmission and illumination. It uses fast pulses of light to
transmit information wirelessly.
The main components of this communication system are
a high brightness white LED, Which acts as a communication
source and
a silicon photodiode which shows good response to visible
wavelength region serving as the receiving element.
LED can be switched on and off to generate digital strings of 1s and 0s.
24. 23
Data can be encoded in the light to generate a new data stream by
varying the flickering rate of the LED. To be clearer, by modulating the
LED light with the data signal, the LED illumination can be used as a
communication source. As the flickering rate is so fast, the LED output
appears constant to the human eye. A data rate of greater than 100
Mbps is possible by using high speed LEDs with appropriate
multiplexing techniques. VLC data rate can be increased by parallel
data transmission using LED arrays where each LED transmits a
different data stream. There are reasons to prefer LED as the light
source in VLC while a lot of other illumination devices like fluorescent
lamp, incandescent bulb etc. are available.
COMPARISION BETWEEN Li-Fi & Wi-Fi
LI-FI is a term of one used to describe visible light
communication technology applied to high speed wireless
communication. It acquired this name due to the similarity to WI-FI,
only using light instead of radio. Wi-Fi is great for general wireless
coverage within buildings, and Li-Fi is ideal for high density wireless
data coverage in confined area and for relieving radio interference
issues, so the two technologies can be considered complimentary.
25. 24
Technology Speed Data density
Wireless (current)
Wi-Fi – IEEE 802.11n 150 Mbps *
Bluetooth 3 Mbps **
IrDA 4 Mbps ***
Wireless (future)
WiGig 2 Gbps **
Giga-IR 1 Gbps ***
Li-Fi >1Gbps >1Gbps ****
Comparison between current and future wireless technology
The table also contains the current wireless technologies that can be
used for transferring data between devices today, i.e. Wi-Fi, Bluetooth
and IrDA. Only Wi-Fi currently offers very high data rates. The IEEE
802.11.n in most implementations provides up to 150Mbit/s (in theory
the standard can go to 600Mbit/s) although in practice you receive
considerably less than this. Note that one out of three of these is an
optical technology.
How it is different?
Li-Fi technology is based on LEDs for the transfer of data. The
transfer of the data can be with the help of all kinds of light, no matter
the part of the spectrum that they belong. That is, the light can belong
to the invisible, ultraviolet or the visible part of the spectrum. Also, the
speed of the internet isincredibly high and you can download movies,
games, music etc in just a few minutes with the help of this technology.
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Also, the technology removes limitations that have been put on the
user by the Wi-Fi. You no more need to be in a region that is Wi-Fi
enabled to have access to the internet. You can simply stand under any
form of light and surf the internet as the connection is made in case of
any light presence. There cannot be anything better than this
technology.
What we have to do?
We have to replace inefficient fluorescents with this new dignitary
of LED lights.
The LED will hold a micro-chip that will do the job of processing
the data.
Light intensity can be modulated at very high speeds to send data
by tiny changes in amplitude.
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Achieving Communication through Light
Let’s start with the foremost communication device which everyone has
in their homes i.e., a Remote Control. A remote control has an
Infrared-LED. It creates a single data stream and the data rate
achieved is around 10000b/s to 20000b/s. Now if we replace the
remote control with a light box, we are able to transmit 1000’s of data
stream in parallel at high speeds. This technology is termed as Spatial
Modulation.
Remote Control Data via LED
Is it a Proven Technology?
Yes, this is already proven.
Harald Haas demonstrated his invention using an ordinary table lamp
that successfully transmitted data at speeds exceeding 10Mbps using
light waves from LED light bulbs to a computer located below the
lamp.
To prove that the light bulb was the source of the data stream, he
periodically blocked the beam of light, causing the connection to drop.
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Overcoming the four issues with RW in Li-Fi
1.Capacity:
10000 times more spectrum than RW.
LEDs are already present.
So we have the infrastructure available and already
installed.
2.Efficiency:
Data through illumination and thus data transmission
comes for free.
LED light consumes less energy
Highly efficient
3.Availability
Light is present everywhere.
4.Security:
Light waves don’t penetrate through walls.
Data is present where there is light.
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Applications of Li-Fi
At present its applications are beyond imagination but still if to think
about few then they are:
Can be used in places where it is difficult to lay the optical fiber
like hospitals. In operation theatre Li-Fi can be used for modern
medical instruments.
In traffic signals Li-Fi can be used which will communicate with
LED lights of the cars and accident numbers can be decreased.
Thousand and millions of street lamps can be transferred to Li-Fi
Lamps to transfer data.
In aircraft Li-Fi can be used for data transmission.
It can be used in petroleum or chemical plants where other
transmission or frequencies could be hazardous.
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Conclusion
he possibilities are numerous and can be explored further. If this
technology can be put into practical use, every bulb can beused
something like a Wi-Fi hotspot to transmit wireless dataand we will
proceed toward the cleaner, greener, safer andbrighter future. The
concept of Li-Fi is currently attracting agreat deal of interest, not least
because it may offer a genuineand very efficient alternative to radio-
based wireless. As agrowing number of people and their many devices
accesswireless internet, the airwaves are becoming
increasinglyclogged, making it more and more difficult to get a
reliable,high-speed signal. This may solve issues such as the shortageof
radio-frequency bandwidth and also allow internet wheretraditional
radio based wireless isn’t allowed such as aircraftor hospitals. One of
the shortcomings however is that it onlywork in direct line of sight.
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