Amanda Werner
Akea Shepard
“Li-Fi, Wireless of The Future?”
Subject Areas: Physical science, science, computer engineering, electrical engineering, and
technology
Associated Lesson: The electromagnetic spectrum, wireless communication
Activity Title: “Li-Fi, Wireless of The Future?”
Header: Insert image 1 here, alight right, wrap text
Grade Level: 6 (6-8)
Activity Dependency: Activity included in template
Time Required: 120 minutes
Group Size: 6 students per group
Cost Per Group: $15.00
Summary
There are many ways devices can connect to each other including component cables,
electrical wires, Ethernet cables, radio waves (Wi-Fi / Bluetooth), infrared signals, and
now, we can even transmit data through light! Electrical and computer engineers are now
exploring using LEDs to transmit high-speed and fully wireless networked communication.
During this activity, students will build their own “Li-Fi” systems that stream music from
cell phones to headphones using light communication!
Engineering Connection
Electrical and computer engineers investigate new technologies that improve the speed
and function of our current systems, including wireless communication. Using light to
transmit data has notable benefits like increasing the speed of data transmission, using an
existing network of lights for a new dual purpose, and improving security. Engineers are
currently exploring new applications for light communication technologies.
Engineering Category: #2 Engineering analysis or partial design
Keywords
Light, Li-Fi, visible light communication (VLC), LED, wireless, streaming, data,
transmission, music, technology, solar panel, electromagnetic spectrum, radio waves,
illuminication.
Educational Standards
 SC.6.N.1.5 Recognize that science involves creativity, not just in designing
experiments, but also in creating explanations that fit evidence.
 SC.6.N.2.3 Recognize that scientists who make contributions to scientific knowledge
come from all kinds of backgrounds and possess varied talents, interests, and goals.
 SC.8.N.4.1 Explain that science is one of the processes that can be used to inform
decision making at the community, state, national, and international levels.
 SC.912.P.12.7 Recognize that nothing travels faster than the speed of light in vacuum
which is the same for all observers no matter how they or the light source are
moving.
Learning Objectives
After this activity, students should be able to:
 Describe some of the existing methods of transmitting data between devices
 Explore how visible light communication can be used as a method to transmit data
 Evaluate the strengths and weaknesses of visible light communication (“Li-Fi”)
 Recognize their personal interests in STEM
Materials List
Each group needs:
 2 audio jacks
 6 alligator clip test leads
 9-volt battery
 Audio wire
 Cellular phone or music-playing device
 Head phones or speakers
 LED light (Super Bright White)
 Resister
 Resister, 220 Ohms
 Small solar panel
Introduction / Motivation
If I wanted to print a worksheet for class, how would I get that information from my
computer to the printer? There are multiple ways that the information from the computer
or data could be transmitted to the printer. It can go through wires or alternately use
wireless communication like Bluetooth or Wi-Fi, which transmit data using radio waves.
Radio waves are part of the nonvisible electromagnetic spectrum. Their signals transmit
not only music to our radio devices but also serve many other functions like allowing
access to the Internet using routers. One characteristic of radio waves are that they
transmit through solid matter like walls or doors. This is can be beneficial, but also adds
security concerns.
To provide wireless users with other options for wireless communication, engineers have
developed “Li-Fi”, the method of using light for data transmission! Li-Fi devices convert
electrical signals into light patterns. LEDs are capable of turning on and off much faster
than the human eye can detect. Receptors receive the signal and convert it back into an
electrical signal before sending it to the device, creating high-speed, fully wireless
networked communication
One advantage of using Li-Fi is that light does not transmit though solid materials, ensuring
localized wireless communication and security. Due to their superior efficiency and lifetime
LED lights are already found in every room in most houses, schools, offices, and businesses.
Using LED lights to transmit Li-Fi signals would allow already existing devices to serve a
second function, proving this to be a practical system. Hence, this technology is sometimes
also called illuminication. Imagine streaming a movie, downloading a document, playing
music, or surfing the web using the clean and efficient light we already illuminate our lives
with! This may be the wireless technology of the future!
Although Li-Fi is considered to be the wireless technology of the future, the idea of using
light for communication is not new! Guess who invented the first communication device
that uses the light. It is the inventor of the phone, Alexander Graham Bell! On June 3, 1880,
Bell and his assistant transmitted a wireless voice telephone message from the roof of the
Franklin School to the window of Bell's laboratory, some 700 ft away. He named this ahead
of the time invention “Photophone”. You can find more information about photophone on
the internet, particularly on Wikipedia. What do you think the reason why photophone has
not become widespread like Bell’s other invention the conventional phone?
One primary reason is the lack of light sources which could be switched on and off fast
enough to transmit large amount of data in short time. LED lights that have this speed have
become available only recently.
Vocabulary / Definitions
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Data – information
Data Transmission - information exchange between devices
LED – light emitting diodes; a type of light source
Li-Fi – (Light Fidelity) a nickname for the light communication technology
Illuminication – Another nick name for the visible light communication technology
derived from the words illumination and communication.
Visible Light Communication (VLC) – Using blinking LED lights to transmit data
wirelessly
Radio Waves – a frequency of waves found on the electromagnetic spectrum, also
most commonly use method of wireless communication
Streaming – a method of data transmission where data is continuously sent or
received
Procedure
1. Collect Materials
First Circuit:
2. Connect 9-volt battery wire to the first test lead.
3. Use the other end of the first test lead to connect the resistor.
4. Using a test lead, connect the resistor to the LED light on the short post.
5. Using a test lead, connect the long post of the LED to the middle post on the audio
jack.
6. Using a test lead, connect the positive end (long end) of the LED to the audio jack
ground (located at the top) using a test lead.
7. Using a test lead, connect either bottom post (right or left ear output) of the audio
jack the battery.
8. Plug an audio cable into the phone audio transmission hole.
9. Plug in the audio cable to the audio jack.
Second Circuit:
10. Connect solar panel to the audio jack using a test lead.
11. Connect the ground of the audio jack to the solar panel using another test lead.
12. Plug in the head phones to the audio jack.
13. Aim the light at the solar panel.
14. Cover and uncover the LED or move it farther from the solar cell to see what will
happen
15. Record findings in lab report
16. As an extension, aim 2 LED lights connected to 2 different phones playing different
audio files on the same solar panel.
17. Record findings.
Background
Teachers and students should be familiar with data transmission, wireless technology, and
the electromagnetic spectrum (light)
Before the Activity
Teacher should introduce topics related to data transmission and talk about the historical
development of wireless communications and express how engineers have strived to
improve this technology using STEM.
With the Students
After the activity, teachers should have groups present their ideas for using this technology,
and then discuss the applications that are currently being explored by engineers.
Attachments
Pictures, worksheet
Safety Issues
If the students are allowed to select which music they will play off of their mobile devices,
they might find media with foul language or inappropriate topics.
Troubleshooting Tips
Try to use a bright LED light so the light can be placed far from the solar cell. Additionally,
different colors and types of LEDs can be tested to see how the change the sound output.
Investigating Questions
See worksheet.
Assessment
Students will be assessed on their understanding through the worksheet and through class
and group discussions.
Pre-Activity Assessment
Review related topics before beginning lesson
Activity Embedded Assessment
Lab report and worksheet
Post-Activity Assessment
Classroom and group discussion
Activity Extensions
Reflect on and design other applications for light communications
Activity Scaling
Additional Multimedia Support
None
Redirect URL
We used: www.sparkfun.com to purchase all of the materials all except for the solar cells,
which are from amazon.com (Small Solar Panel 3.0V 200mA with wires).
Contributors
Akea Shephard, Amanda Werner, Dr. Nezih Pala, David Andrade
Supporting Program
Research Experience for Teachers at Florida International University School of Engineering
and Computing
Group Member Names:
______________________________________________________________________________
______________________________________________________________________________
Date: ______________________________ Period:__________________________________
Li-Fi: Wireless of the Future?
Select one student as the recorder and one student as the presenter. Work as a group
to complete this worksheet regarding Li-Fi (Light Communication). After you have
completed both sides, the presenter will introduce your ideas in a class discussion.
3 W’s
As a group, discuss the following categories regarding light communication and
write a short description of how you felt.
Wow
Wonder
Why
1. What “wowed” you about this technology?
(Student responses will vary)
2. What do you “wonder” about regarding this technology?
(Student responses will vary)
3. “Why” is it important that engineers are exploring the use of Li-Fi?
(We have more technology than ever that depends on wireless data
communication. Using multiple sources of data transmission like Wi-Fi and Li-Fi
together will allow us to have more connected devices. Lifi helps solve some of
the current concerns like security and speed. We can utilize lights we already
have for this technology. (Student responses may vary.)
Compare and contrast the use of radio waves vs. light using a Venn Diagram:
4.
(Possible responses: Compare: Data can be transmitted through both visible
light and radio waves. Contrast(Light): Fast, cannot travel through walls.
Contrast(Radio): travels far through some materials, slower)
Engineering with Light
1. Brainstorm applications for this technology and record some of your ideas:
(Possible responses: [student responses will vary] using classroom light for
computer internet connection, street lights helping with directions, lights in front
stores giving coupons, etc.)
2. Chose one of your ideas and write a detailed plan on how this can be
implemented and used. Draw a diagram of your design and label the parts
involved in your design.
(Student responses will vary. Must include labels)
3. Are these technologies currently available? What would be the biggest
challenge in producing your design and how would you overcome the
challenge?
(Student responses will vary. Challenge students to think of possible obstacles like
cost, constant lighting, limitations of Li-Fi, competition or push back from other
means of transmitting data, etc. as well as possible solutions)
4. Was your group more interested in the science, technology, or engineering
aspects of this exercise and why?
(Student responses will vary. Must include explanation.)